On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: Hi All, OS Version: CentOS 8 389-DS Version: 1.4.3.22 from EPEL I have a server set up with minssf=256 and have been surprised that either 389-DS, or openssl, does not appear to be doing what I would consider a logical TLS negotiation. I had thought that the system would start with the strongest cipher and then negotiate down to something that was acceptable. Instead, I'm finding that I have to nail up the ciphers to something that the 389-DS server both recognizes and is within the expected SSF. Is this expected behavior or do I have something configured incorrectly?

Thanks, Trevor -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information -- _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

On 23 Apr 2021, at 03:23, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: Hi William, In terms of the STARTTLS bits (in theory) properly configuring your client software mitigates the password leak risk. But this also happens with pure (non-RFC) LDAPS connections.

The docs note that minssf applies to the crypto required bits as well as the SASL layer. Ignoring most of that, my issue is that I don't understand why I have to nail my client software to ciphers explicitly known by 389-DS instead of the two negotiating the strongest things possible out of the gate. For instance, if I use AES256 with a minssf=256, everything works just fine. But, if I use AES128:AES256:@STRENGTH (which should sort strongest to weakest) then access is denied.

How do I get 389-DS to negotiate the strongest ciphers first (regardless of the method)?

Thanks, Trevor On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de&gt; wrote: Hi there, > On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > Hi All, > > OS Version: CentOS 8 > 389-DS Version: 1.4.3.22 from EPEL > > I have a server set up with minssf=256 and have been surprised that either 389-DS, or openssl, does not appear to be doing what I would consider a logical TLS negotiation. > > I had thought that the system would start with the strongest cipher and then negotiate down to something that was acceptable. > > Instead, I'm finding that I have to nail up the ciphers to something that the 389-DS server both recognizes and is within the expected SSF. > > Is this expected behavior or do I have something configured incorrectly? That's not what minssf does. minssf says "during a bind operation, reject if the encryption strength used is less than 256 bits or equivalent". The "bit strength" is arbitrary though, because it's a concept from sasl, and generally is very broken. Remember, minssf does NOT do what you think though! Because bind is the *first* message on the wire, the series of operations is client server open plain text conn -> <- accept connection send bind on conn -> <- reject due to minsff too weak. So you have already leaked the password! The only way to ensure this does not occur is to set "nsslapd-port: 0" which disables plaintext. Then you *only* use ldaps on port 636, which is guarantee encrypted from the start. It is worth noting that the use of starttls over ldap, does *NOT* mitigate this issue, for a similar reason. Caveat: If you are using kerberos/gssapi you can NOT disable plaintext ldap due to these protocols attempting to install their own encryption layers. Hope that helps, > > Thanks, > > Trevor > > -- > Trevor Vaughan > Vice President, Onyx Point, Inc > (410) 541-6699 x788 > > -- This account not approved for unencrypted proprietary information -- > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure — Sincerely, William Brown Senior Software Engineer, 389 Directory Server SUSE Labs, Australia _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information -- _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

Hi William, In terms of the STARTTLS bits (in theory) properly configuring your client software mitigates the password leak risk. But this also happens with pure (non-RFC) LDAPS connections. The docs note that minssf applies to the crypto required bits as well as the SASL layer. Ignoring most of that, my issue is that I don't understand why I have to nail my client software to ciphers explicitly known by 389-DS instead of the two negotiating the strongest things possible out of the gate. For instance, if I use AES256 with a minssf=256, everything works just fine. But, if I use AES128:AES256:@STRENGTH (which should sort strongest to weakest) then access is denied. How do I get 389-DS to negotiate the strongest ciphers first (regardless of the method)? Thanks, Trevor On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de&gt; wrote: > Hi there, > > > On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; > wrote: > > > > Hi All, > > > > OS Version: CentOS 8 > > 389-DS Version: 1.4.3.22 from EPEL > > > > I have a server set up with minssf=256 and have been surprised that > either 389-DS, or openssl, does not appear to be doing what I would > consider a logical TLS negotiation. > > > > I had thought that the system would start with the strongest cipher and > then negotiate down to something that was acceptable. > > > > Instead, I'm finding that I have to nail up the ciphers to something > that the 389-DS server both recognizes and is within the expected SSF. > > > > Is this expected behavior or do I have something configured incorrectly? > > That's not what minssf does. > > minssf says "during a bind operation, reject if the encryption strength > used is less than 256 bits or equivalent". > > The "bit strength" is arbitrary though, because it's a concept from sasl, > and generally is very broken. > > Remember, minssf does NOT do what you think though! Because bind is the > *first* message on the wire, the series of operations is > > > client server > open plain text conn -> > <- accept connection > send bind on conn -> > <- reject due to minsff too weak. > > > So you have already leaked the password! > > > The only way to ensure this does not occur is to set "nsslapd-port: 0" > which disables plaintext. Then you *only* use ldaps on port 636, which is > guarantee encrypted from the start. > > It is worth noting that the use of starttls over ldap, does *NOT* > mitigate this issue, for a similar reason. > > > Caveat: If you are using kerberos/gssapi you can NOT disable plaintext > ldap due to these protocols attempting to install their own encryption > layers. > > > Hope that helps, > > > > > > Thanks, > > > > Trevor > > > > -- > > Trevor Vaughan > > Vice President, Onyx Point, Inc > > (410) 541-6699 x788 > > > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > > — > Sincerely, > > William Brown > > Senior Software Engineer, 389 Directory Server > SUSE Labs, Australia > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information -- _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

On 23 Apr 2021, at 22:11, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: Bill and Pierre, Thanks for the responses! It sounds like I have to figure out how to configure the NSS library for 389-DS specifically. In EL8+ I know that I can configure the global crypto policy but I'm hoping that I can do it for the specific application. I haven't found anything in the documentation so far but at least this gets me pointed in the right direction. Thanks, Trevor On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier <progier(a)redhat.com&gt; wrote: Hi Trevor, I do not think it is possible to specify the cypher order negotiation: I am not sure whether TLS protocol allow to specify an order when negotiating the cypher, but at 389 level there is no way to specify an order: The NSS security layer provides the list of supported cypher and 389 use nsSSL3Ciphers config parameter to enable/disable theses cyphers in the list (without changing the order) So my feeling is that if there is an order it is up to the different security layer implementations and may differs between the applications, Regards, Pierre On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: Hi William, In terms of the STARTTLS bits (in theory) properly configuring your client software mitigates the password leak risk. But this also happens with pure (non-RFC) LDAPS connections. The docs note that minssf applies to the crypto required bits as well as the SASL layer. Ignoring most of that, my issue is that I don't understand why I have to nail my client software to ciphers explicitly known by 389-DS instead of the two negotiating the strongest things possible out of the gate. For instance, if I use AES256 with a minssf=256, everything works just fine. But, if I use AES128:AES256:@STRENGTH (which should sort strongest to weakest) then access is denied. How do I get 389-DS to negotiate the strongest ciphers first (regardless of the method)? Thanks, Trevor On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de&gt; wrote: Hi there, > On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > Hi All, > > OS Version: CentOS 8 > 389-DS Version: 1.4.3.22 from EPEL > > I have a server set up with minssf=256 and have been surprised that either 389-DS, or openssl, does not appear to be doing what I would consider a logical TLS negotiation. > > I had thought that the system would start with the strongest cipher and then negotiate down to something that was acceptable. > > Instead, I'm finding that I have to nail up the ciphers to something that the 389-DS server both recognizes and is within the expected SSF. > > Is this expected behavior or do I have something configured incorrectly? That's not what minssf does. minssf says "during a bind operation, reject if the encryption strength used is less than 256 bits or equivalent". The "bit strength" is arbitrary though, because it's a concept from sasl, and generally is very broken. Remember, minssf does NOT do what you think though! Because bind is the *first* message on the wire, the series of operations is client server open plain text conn -> <- accept connection send bind on conn -> <- reject due to minsff too weak. So you have already leaked the password! The only way to ensure this does not occur is to set "nsslapd-port: 0" which disables plaintext. Then you *only* use ldaps on port 636, which is guarantee encrypted from the start. It is worth noting that the use of starttls over ldap, does *NOT* mitigate this issue, for a similar reason. Caveat: If you are using kerberos/gssapi you can NOT disable plaintext ldap due to these protocols attempting to install their own encryption layers. Hope that helps, > > Thanks, > > Trevor > > -- > Trevor Vaughan > Vice President, Onyx Point, Inc > (410) 541-6699 x788 > > -- This account not approved for unencrypted proprietary information -- > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure — Sincerely, William Brown Senior Software Engineer, 389 Directory Server SUSE Labs, Australia _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information -- _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure -- -- 389 Directory Server Development Team _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information -- _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

William, I do apologize! I'll keep that in mind in the future. Thanks again for your help, Trevor On Fri, Apr 23, 2021, 7:50 PM William Brown <wbrown(a)suse.de&gt; wrote: > Sorry to call this out, but my name is "William" not "Bill". I have > personal reasons to dislike being called that name. > > Regardless, happy to help out :) > > > On 23 Apr 2021, at 22:11, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; > wrote: > > > > Bill and Pierre, > > > > Thanks for the responses! > > > > It sounds like I have to figure out how to configure the NSS library > for 389-DS specifically. > > > > In EL8+ I know that I can configure the global crypto policy but I'm > hoping that I can do it for the specific application. I haven't found > anything in the documentation so far but at least this gets me pointed in > the right direction. > > > > Thanks, > > > > Trevor > > > > On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier <progier(a)redhat.com&gt; > wrote: > > Hi Trevor, > > > > I do not think it is possible to specify the cypher order negotiation: > > I am not sure whether TLS protocol allow to specify an order when > negotiating the cypher, > > but at 389 level there is no way to specify an order: > > The NSS security layer provides the list of supported cypher and 389 > use > > nsSSL3Ciphers config parameter to enable/disable theses cyphers in the > list (without changing the order) > > > > So my feeling is that if there is an order it is up to the > different > > security layer implementations and may differs between the > applications, > > > > Regards, > > Pierre > > > > On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; > wrote: > > Hi William, > > > > In terms of the STARTTLS bits (in theory) properly configuring your > client software mitigates the password leak risk. But this also happens > with pure (non-RFC) LDAPS connections. > > > > The docs note that minssf applies to the crypto required bits as well > as the SASL layer. > > > > Ignoring most of that, my issue is that I don't understand why I have > to nail my client software to ciphers explicitly known by 389-DS instead of > the two negotiating the strongest things possible out of the gate. > > > > For instance, if I use AES256 with a minssf=256, everything works just > fine. > > > > But, if I use AES128:AES256:@STRENGTH (which should sort strongest to > weakest) then access is denied. > > > > How do I get 389-DS to negotiate the strongest ciphers first > (regardless of the method)? > > > > Thanks, > > > > Trevor > > > > On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de&gt; wrote: > > Hi there, > > > > > On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; > wrote: > > > > > > Hi All, > > > > > > OS Version: CentOS 8 > > > 389-DS Version: 1.4.3.22 from EPEL > > > > > > I have a server set up with minssf=256 and have been surprised that > either 389-DS, or openssl, does not appear to be doing what I would > consider a logical TLS negotiation. > > > > > > I had thought that the system would start with the strongest cipher > and then negotiate down to something that was acceptable. > > > > > > Instead, I'm finding that I have to nail up the ciphers to something > that the 389-DS server both recognizes and is within the expected SSF. > > > > > > Is this expected behavior or do I have something configured > incorrectly? > > > > That's not what minssf does. > > > > minssf says "during a bind operation, reject if the encryption strength > used is less than 256 bits or equivalent". > > > > The "bit strength" is arbitrary though, because it's a concept from > sasl, and generally is very broken. > > > > Remember, minssf does NOT do what you think though! Because bind is the > *first* message on the wire, the series of operations is > > > > > > client server > > open plain text conn -> > > <- accept connection > > send bind on conn -> > > <- reject due to minsff too weak. > > > > > > So you have already leaked the password! > > > > > > The only way to ensure this does not occur is to set "nsslapd-port: 0" > which disables plaintext. Then you *only* use ldaps on port 636, which is > guarantee encrypted from the start. > > > > It is worth noting that the use of starttls over ldap, does *NOT* > mitigate this issue, for a similar reason. > > > > > > Caveat: If you are using kerberos/gssapi you can NOT disable plaintext > ldap due to these protocols attempting to install their own encryption > layers. > > > > > > Hope that helps, > > > > > > > > > > Thanks, > > > > > > Trevor > > > > > > -- > > > Trevor Vaughan > > > Vice President, Onyx Point, Inc > > > (410) 541-6699 x788 > > > > > > -- This account not approved for unencrypted proprietary information > -- > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > > To unsubscribe send an email to > 389-users-leave(a)lists.fedoraproject.org > > > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > > > > — > > Sincerely, > > > > William Brown > > > > Senior Software Engineer, 389 Directory Server > > SUSE Labs, Australia > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > > > > > > -- > > Trevor Vaughan > > Vice President, Onyx Point, Inc > > (410) 541-6699 x788 > > > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > > > > > > -- > > -- > > > > 389 Directory Server Development Team > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > > > > > > -- > > Trevor Vaughan > > Vice President, Onyx Point, Inc > > (410) 541-6699 x788 > > > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > > — > Sincerely, > > William Brown > > Senior Software Engineer, 389 Directory Server > SUSE Labs, Australia > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

On 24 Apr 2021, at 22:30, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: Hi Marc, I was under the impression that it would pick the highest supported, but that doesn't seem to be what is happening based on my previous example. Instead, it seems to just be picking the first compatible, regardless of strength.

Trevor On Fri, Apr 23, 2021, 10:03 PM Marc Sauton <msauton(a)redhat.com&gt; wrote: about ciphers order and TLS cipher suite discovery, NSS will pick the one with highest strength from the available ciphers, and compatible with the TLS client ( handshake) you can check the configuration with for example (replace the string m1 with an instance name): dsconf m1 security get dsconf m1 security ciphers list dsconf m1 security ciphers list --supported | less dsconf m1 security ciphers list --enabled ldapsearch -o ldif-wrap=no -LLLxD "cn=Directory Manager" -W -b cn=encryption,cn=config | less and to set ciphers (can be "delicate"): /usr/lib64/nss/unsupported-tools/listsuites | grep -B1 --no-group-separator "Enabled" | less dsconf m1 security ciphers set xxxxx doc ref: https://access.redhat.com/documentation/en-us/red_hat_directory_server/11... and NSS source: ./lib/ssl/ssl3con.c ./lib/ssl/sslenum.c On Fri, Apr 23, 2021 at 4:57 PM Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: William, I do apologize! I'll keep that in mind in the future. Thanks again for your help, Trevor On Fri, Apr 23, 2021, 7:50 PM William Brown <wbrown(a)suse.de&gt; wrote: Sorry to call this out, but my name is "William" not "Bill". I have personal reasons to dislike being called that name. Regardless, happy to help out :) > On 23 Apr 2021, at 22:11, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > Bill and Pierre, > > Thanks for the responses! > > It sounds like I have to figure out how to configure the NSS library for 389-DS specifically. > > In EL8+ I know that I can configure the global crypto policy but I'm hoping that I can do it for the specific application. I haven't found anything in the documentation so far but at least this gets me pointed in the right direction. > > Thanks, > > Trevor > > On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier <progier(a)redhat.com&gt; wrote: > Hi Trevor, > > I do not think it is possible to specify the cypher order negotiation: > I am not sure whether TLS protocol allow to specify an order when negotiating the cypher, > but at 389 level there is no way to specify an order: > The NSS security layer provides the list of supported cypher and 389 use > nsSSL3Ciphers config parameter to enable/disable theses cyphers in the list (without changing the order) > > So my feeling is that if there is an order it is up to the different > security layer implementations and may differs between the applications, > > Regards, > Pierre > > On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > Hi William, > > In terms of the STARTTLS bits (in theory) properly configuring your client software mitigates the password leak risk. But this also happens with pure (non-RFC) LDAPS connections. > > The docs note that minssf applies to the crypto required bits as well as the SASL layer. > > Ignoring most of that, my issue is that I don't understand why I have to nail my client software to ciphers explicitly known by 389-DS instead of the two negotiating the strongest things possible out of the gate. > > For instance, if I use AES256 with a minssf=256, everything works just fine. > > But, if I use AES128:AES256:@STRENGTH (which should sort strongest to weakest) then access is denied. > > How do I get 389-DS to negotiate the strongest ciphers first (regardless of the method)? > > Thanks, > > Trevor > > On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de&gt; wrote: > Hi there, > > > On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > > > Hi All, > > > > OS Version: CentOS 8 > > 389-DS Version: 1.4.3.22 from EPEL > > > > I have a server set up with minssf=256 and have been surprised that either 389-DS, or openssl, does not appear to be doing what I would consider a logical TLS negotiation. > > > > I had thought that the system would start with the strongest cipher and then negotiate down to something that was acceptable. > > > > Instead, I'm finding that I have to nail up the ciphers to something that the 389-DS server both recognizes and is within the expected SSF. > > > > Is this expected behavior or do I have something configured incorrectly? > > That's not what minssf does. > > minssf says "during a bind operation, reject if the encryption strength used is less than 256 bits or equivalent". > > The "bit strength" is arbitrary though, because it's a concept from sasl, and generally is very broken. > > Remember, minssf does NOT do what you think though! Because bind is the *first* message on the wire, the series of operations is > > > client server > open plain text conn -> > <- accept connection > send bind on conn -> > <- reject due to minsff too weak. > > > So you have already leaked the password! > > > The only way to ensure this does not occur is to set "nsslapd-port: 0" which disables plaintext. Then you *only* use ldaps on port 636, which is guarantee encrypted from the start. > > It is worth noting that the use of starttls over ldap, does *NOT* mitigate this issue, for a similar reason. > > > Caveat: If you are using kerberos/gssapi you can NOT disable plaintext ldap due to these protocols attempting to install their own encryption layers. > > > Hope that helps, > > > > > > Thanks, > > > > Trevor > > > > -- > > Trevor Vaughan > > Vice President, Onyx Point, Inc > > (410) 541-6699 x788 > > > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > — > Sincerely, > > William Brown > > Senior Software Engineer, 389 Directory Server > SUSE Labs, Australia > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > -- > Trevor Vaughan > Vice President, Onyx Point, Inc > (410) 541-6699 x788 > > -- This account not approved for unencrypted proprietary information -- > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > -- > -- > > 389 Directory Server Development Team > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > -- > Trevor Vaughan > Vice President, Onyx Point, Inc > (410) 541-6699 x788 > > -- This account not approved for unencrypted proprietary information -- > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure — Sincerely, William Brown Senior Software Engineer, 389 Directory Server SUSE Labs, Australia _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

On 25 Apr 2021, at 11:39, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: Well, in this case, I've got to be able to work with regulatory requirements so not much I can do there. Trevor On Sat, Apr 24, 2021, 9:03 PM William Brown <wbrown(a)suse.de&gt; wrote: > On 24 Apr 2021, at 22:30, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > Hi Marc, > > I was under the impression that it would pick the highest supported, but that doesn't seem to be what is happening based on my previous example. > > Instead, it seems to just be picking the first compatible, regardless of strength. It choose aes128 over 256 because of processing speed, and "strong enough". > > Trevor > > On Fri, Apr 23, 2021, 10:03 PM Marc Sauton <msauton(a)redhat.com&gt; wrote: > about ciphers order and TLS cipher suite discovery, NSS will pick the one with highest strength from the available ciphers, and compatible with the TLS client ( handshake) > > you can check the configuration with for example (replace the string m1 with an instance name): > dsconf m1 security get > dsconf m1 security ciphers list > dsconf m1 security ciphers list --supported | less > dsconf m1 security ciphers list --enabled > ldapsearch -o ldif-wrap=no -LLLxD "cn=Directory Manager" -W -b cn=encryption,cn=config | less > > and to set ciphers (can be "delicate"): > /usr/lib64/nss/unsupported-tools/listsuites | grep -B1 --no-group-separator "Enabled" | less > dsconf m1 security ciphers set xxxxx > > doc ref: > https://access.redhat.com/documentation/en-us/red_hat_directory_server/11... > > and NSS source: > ./lib/ssl/ssl3con.c > ./lib/ssl/sslenum.c > > > On Fri, Apr 23, 2021 at 4:57 PM Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > William, > > I do apologize! I'll keep that in mind in the future. > > Thanks again for your help, > > Trevor > > On Fri, Apr 23, 2021, 7:50 PM William Brown <wbrown(a)suse.de&gt; wrote: > Sorry to call this out, but my name is "William" not "Bill". I have personal reasons to dislike being called that name. > > Regardless, happy to help out :) > > > On 23 Apr 2021, at 22:11, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > > > Bill and Pierre, > > > > Thanks for the responses! > > > > It sounds like I have to figure out how to configure the NSS library for 389-DS specifically. > > > > In EL8+ I know that I can configure the global crypto policy but I'm hoping that I can do it for the specific application. I haven't found anything in the documentation so far but at least this gets me pointed in the right direction. > > > > Thanks, > > > > Trevor > > > > On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier <progier(a)redhat.com&gt; wrote: > > Hi Trevor, > > > > I do not think it is possible to specify the cypher order negotiation: > > I am not sure whether TLS protocol allow to specify an order when negotiating the cypher, > > but at 389 level there is no way to specify an order: > > The NSS security layer provides the list of supported cypher and 389 use > > nsSSL3Ciphers config parameter to enable/disable theses cyphers in the list (without changing the order) > > > > So my feeling is that if there is an order it is up to the different > > security layer implementations and may differs between the applications, > > > > Regards, > > Pierre > > > > On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > Hi William, > > > > In terms of the STARTTLS bits (in theory) properly configuring your client software mitigates the password leak risk. But this also happens with pure (non-RFC) LDAPS connections. > > > > The docs note that minssf applies to the crypto required bits as well as the SASL layer. > > > > Ignoring most of that, my issue is that I don't understand why I have to nail my client software to ciphers explicitly known by 389-DS instead of the two negotiating the strongest things possible out of the gate. > > > > For instance, if I use AES256 with a minssf=256, everything works just fine. > > > > But, if I use AES128:AES256:@STRENGTH (which should sort strongest to weakest) then access is denied. > > > > How do I get 389-DS to negotiate the strongest ciphers first (regardless of the method)? > > > > Thanks, > > > > Trevor > > > > On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de&gt; wrote: > > Hi there, > > > > > On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com&gt; wrote: > > > > > > Hi All, > > > > > > OS Version: CentOS 8 > > > 389-DS Version: 1.4.3.22 from EPEL > > > > > > I have a server set up with minssf=256 and have been surprised that either 389-DS, or openssl, does not appear to be doing what I would consider a logical TLS negotiation. > > > > > > I had thought that the system would start with the strongest cipher and then negotiate down to something that was acceptable. > > > > > > Instead, I'm finding that I have to nail up the ciphers to something that the 389-DS server both recognizes and is within the expected SSF. > > > > > > Is this expected behavior or do I have something configured incorrectly? > > > > That's not what minssf does. > > > > minssf says "during a bind operation, reject if the encryption strength used is less than 256 bits or equivalent". > > > > The "bit strength" is arbitrary though, because it's a concept from sasl, and generally is very broken. > > > > Remember, minssf does NOT do what you think though! Because bind is the *first* message on the wire, the series of operations is > > > > > > client server > > open plain text conn -> > > <- accept connection > > send bind on conn -> > > <- reject due to minsff too weak. > > > > > > So you have already leaked the password! > > > > > > The only way to ensure this does not occur is to set "nsslapd-port: 0" which disables plaintext. Then you *only* use ldaps on port 636, which is guarantee encrypted from the start. > > > > It is worth noting that the use of starttls over ldap, does *NOT* mitigate this issue, for a similar reason. > > > > > > Caveat: If you are using kerberos/gssapi you can NOT disable plaintext ldap due to these protocols attempting to install their own encryption layers. > > > > > > Hope that helps, > > > > > > > > > > Thanks, > > > > > > Trevor > > > > > > -- > > > Trevor Vaughan > > > Vice President, Onyx Point, Inc > > > (410) 541-6699 x788 > > > > > > -- This account not approved for unencrypted proprietary information -- > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > — > > Sincerely, > > > > William Brown > > > > Senior Software Engineer, 389 Directory Server > > SUSE Labs, Australia > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > > > -- > > Trevor Vaughan > > Vice President, Onyx Point, Inc > > (410) 541-6699 x788 > > > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > > > -- > > -- > > > > 389 Directory Server Development Team > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > > > -- > > Trevor Vaughan > > Vice President, Onyx Point, Inc > > (410) 541-6699 x788 > > > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > — > Sincerely, > > William Brown > > Senior Software Engineer, 389 Directory Server > SUSE Labs, Australia > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure — Sincerely, William Brown Senior Software Engineer, 389 Directory Server SUSE Labs, Australia _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

Going full circle on this, I confirmed using s_client that what I was seeing was indeed happening but not for the reason that I thought it was. Given that the min_ssf is 256, the connection requires a 256-bit cipher and hash to communicate with the server. Strangely, the internal strength logic on the 389-DS side appears to pick ECDHE-RSA-AES128-GCM-SHA256 *before* ECDHE-RSA-AES256-GCM-SHA384. Likewise, if I add any of the AES128 ciphers to the list after the AES256 ciphers, one of the 128-bit ciphers will be chosen first. This seems incorrect given that the server should be using the strongest cipher suite available if possible. The client cipher order preference is completely ignored (which is fine). As pointed out in the last response, I did indeed need to explicitly enable only the 256-bit+ hash/cipher combinations in the confusingly-named nsSSL3Ciphers attribute. After figuring this out and dumping the internal supported cipher list, I can confirm that the ciphers in the nsSSL3Ciphers list are the only ones that are presented to the client. While not ideal, this does provide a solution to the issue where I don't have to tell all system users that they need to nail up the cipher lists on the client side in order for things to function properly. But that leaves me with two questions: 1) Why, when the nsslapd-minssf option is set in the global configuration, does 389-DS not automatically prune any options that will result in an unsuccessful connection. 2) Why is the internal cipher sorting order choosing weaker cipher suites before stronger ones?

On Mon, Apr 26, 2021 at 11:50 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de>> wrote: Then youll need to disable everything except aes256 then I suspect ... :( > On 25 Apr 2021, at 11:39, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > Well, in this case, I've got to be able to work with regulatory requirements so not much I can do there. > > Trevor > > On Sat, Apr 24, 2021, 9:03 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de>> wrote: > > > > On 24 Apr 2021, at 22:30, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > > Hi Marc, > > > > I was under the impression that it would pick the highest supported, but that doesn't seem to be what is happening based on my previous example. > > > > Instead, it seems to just be picking the first compatible, regardless of strength. > > It choose aes128 over 256 because of processing speed, and "strong enough". > > > > > Trevor > > > > On Fri, Apr 23, 2021, 10:03 PM Marc Sauton <msauton(a)redhat.com <mailto:msauton@redhat.com>> wrote: > > about ciphers order and TLS cipher suite discovery, NSS will pick the one with highest strength from the available ciphers, and compatible with the TLS client ( handshake) > > > > you can check the configuration with for example (replace the string m1 with an instance name): > > dsconf m1 security get > > dsconf m1 security ciphers list > > dsconf m1 security ciphers list --supported | less > > dsconf m1 security ciphers list --enabled > > ldapsearch -o ldif-wrap=no -LLLxD "cn=Directory Manager" -W  -b cn=encryption,cn=config | less > > > > and to set ciphers (can be "delicate"): > > /usr/lib64/nss/unsupported-tools/listsuites | grep -B1 --no-group-separator "Enabled" | less > > dsconf m1 security ciphers set xxxxx > > > > doc ref: > > https://access.redhat.com/documentation/en-us/red_hat_directory_server/11... > > > > and NSS source: > > ./lib/ssl/ssl3con.c > > ./lib/ssl/sslenum.c > > > > > > On Fri, Apr 23, 2021 at 4:57 PM Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > William, > > > > I do apologize! I'll keep that in mind in the future. > > > > Thanks again for your help, > > > > Trevor > > > > On Fri, Apr 23, 2021, 7:50 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de>> wrote: > > Sorry to call this out, but my name is "William" not "Bill". I have personal reasons to dislike being called that name. > > > > Regardless, happy to help out :) > > > > > On 23 Apr 2021, at 22:11, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > > > > Bill and Pierre, > > > > > > Thanks for the responses! > > > > > > It sounds like I have to figure out how to configure the NSS library for 389-DS specifically. > > > > > > In EL8+ I know that I can configure the global crypto policy but I'm hoping that I can do it for the specific application. I haven't found anything in the documentation so far but at least this gets me pointed in the right direction. > > > > > > Thanks, > > > > > > Trevor > > > > > > On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier <progier(a)redhat.com <mailto:progier@redhat.com>> wrote: > > > Hi Trevor, > > > > > > I do not think it is possible to specify the cypher order negotiation: > > >      I am not sure whether TLS protocol allow to specify an order when negotiating the cypher, > > >      but at 389 level there is no way to specify an order: > > > The NSS security layer provides the list of supported cypher and 389 use > > > nsSSL3Ciphers config parameter to enable/disable theses cyphers in the list (without changing the order) > > > > > >     So my feeling is that if there is an order it is up to the different > > >      security layer implementations and may differs between the applications, > > > > > > Regards, > > >    Pierre > > > > > > On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > Hi William, > > > > > > In terms of the STARTTLS bits (in theory) properly configuring your client software mitigates the password leak risk. But this also happens with pure (non-RFC) LDAPS connections. > > > > > > The docs note that minssf applies to the crypto required bits as well as the SASL layer. > > > > > > Ignoring most of that, my issue is that I don't understand why I have to nail my client software to ciphers explicitly known by 389-DS instead of the two negotiating the strongest things possible out of the gate. > > > > > > For instance, if I use AES256 with a minssf=256, everything works just fine. > > > > > > But, if I use AES128:AES256:@STRENGTH (which should sort strongest to weakest) then access is denied. > > > > > > How do I get 389-DS to negotiate the strongest ciphers first (regardless of the method)? > > > > > > Thanks, > > > > > > Trevor > > > > > > On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de>> wrote: > > > Hi there, > > > > > > > On 22 Apr 2021, at 03:52, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > > > > > > Hi All, > > > > > > > > OS Version: CentOS 8 > > > > 389-DS Version: 1.4.3.22 from EPEL > > > > > > > > I have a server set up with minssf=256 and have been surprised that either 389-DS, or openssl, does not appear to be doing what I would consider a logical TLS negotiation. > > > > > > > > I had thought that the system would start with the strongest cipher and then negotiate down to something that was acceptable. > > > > > > > > Instead, I'm finding that I have to nail up the ciphers to something that the 389-DS server both recognizes and is within the expected SSF. > > > > > > > > Is this expected behavior or do I have something configured incorrectly? > > > > > > That's not what minssf does. > > > > > > minssf says "during a bind operation, reject if the encryption strength used is less than 256 bits or equivalent". > > > > > > The "bit strength" is arbitrary though, because it's a concept from sasl, and generally is very broken. > > > > > > Remember, minssf does NOT do what you think though! Because bind is the *first* message on the wire, the series of operations is > > > > > > > > >    client                   server > > > open plain text conn  ->    > > >                       <-   accept connection > > > send bind on conn     ->    > > >                       <-   reject due to minsff too weak. > > > > > > > > > So you have already leaked the password! > > > > > > > > > The only way to ensure this does not occur is to set "nsslapd-port: 0" which disables plaintext. Then you *only* use ldaps on port 636, which is guarantee encrypted from the start. > > > > > > It is worth noting that the use of starttls over ldap, does *NOT* mitigate this issue, for a similar reason. > > > > > > > > > Caveat: If you are using kerberos/gssapi you can NOT disable plaintext ldap due to these protocols attempting to install their own encryption layers. > > > > > > > > > Hope that helps, > > > > > > > > > > > > > > Thanks, > > > > > > > > Trevor > > > > > > > > -- > > > > Trevor Vaughan > > > > Vice President, Onyx Point, Inc > > > > (410) 541-6699 x788 > > > > > > > > -- This account not approved for unencrypted proprietary information -- > > > > _______________________________________________ > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > > > — > > > Sincerely, > > > > > > William Brown > > > > > > Senior Software Engineer, 389 Directory Server > > > SUSE Labs, Australia > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > > > > > > -- > > > Trevor Vaughan > > > Vice President, Onyx Point, Inc > > > (410) 541-6699 x788 > > > > > > -- This account not approved for unencrypted proprietary information -- > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > > > > > > -- > > > -- > > > > > > 389 Directory Server Development Team > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > > > > > > -- > > > Trevor Vaughan > > > Vice President, Onyx Point, Inc > > > (410) 541-6699 x788 > > > > > > -- This account not approved for unencrypted proprietary information -- > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > > > — > > Sincerely, > > > > William Brown > > > > Senior Software Engineer, 389 Directory Server > > SUSE Labs, Australia > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > > — > Sincerely, > > William Brown > > Senior Software Engineer, 389 Directory Server > SUSE Labs, Australia > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure — Sincerely, William Brown Senior Software Engineer, 389 Directory Server SUSE Labs, Australia _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information -- _______________________________________________ 389-users mailing list -- 389-users(a)lists.fedoraproject.org To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure

How odd, maybe it's the version in EPEL.

On Tue, Apr 27, 2021 at 6:32 PM Rob Crittenden <rcritten(a)redhat.com <mailto:rcritten@redhat.com>> wrote: Trevor Vaughan wrote: > Going full circle on this, I confirmed using s_client that what I was > seeing was indeed happening but not for the reason that I thought it was. > > Given that the min_ssf is 256, the connection requires a 256-bit cipher > and hash to communicate with the server. > > Strangely, the internal strength logic on the 389-DS side appears to > pick ECDHE-RSA-AES128-GCM-SHA256 *before* ECDHE-RSA-AES256-GCM-SHA384. > Likewise, if I add any of the AES128 ciphers to the list after the > AES256 ciphers, one of the 128-bit ciphers will be chosen first. This > seems incorrect given that the server should be using the strongest > cipher suite available if possible. > > The client cipher order preference is completely ignored (which is fine). > > As pointed out in the last response, I did indeed need to explicitly > enable only the 256-bit+ hash/cipher combinations in the > confusingly-named nsSSL3Ciphers attribute. > > After figuring this out and dumping the internal supported cipher list, > I can confirm that the ciphers in the nsSSL3Ciphers list are the only > ones that are presented to the client. > > While not ideal, this does provide a solution to the issue where I don't > have to tell all system users that they need to nail up the cipher lists > on the client side in order for things to function properly. > > But that leaves me with two questions: > > 1) Why, when the nsslapd-minssf option is set in the global > configuration, does 389-DS not automatically prune any options that will > result in an unsuccessful connection. > > 2) Why is the internal cipher sorting order choosing weaker cipher > suites before stronger ones? I'm pretty sure that 389-ds still uses NSS for server-side crypto and unless something has changed NSS doesn't do cipher sorting. It picks the "best" for you. AFAIR the server has no say in the matter. But, as a goof I used a pure NSS server tool to see what happens and it picked the expected cipher. Enable your two ciphers (in hex form): $ /usr/lib64/nss/unsupported-tools/selfserv -n Server-Cert -d /etc/dirsrv/slapd-EXAMPLE-TEST/ -p 8389 -f /etc/dirsrv/slapd-EXAMPLE-TEST/pwdfile.txt -c :C02F -c :C030 -v -V tls1.2:tls1.2 run s_client: New, TLSv1.2, Cipher is ECDHE-RSA-AES256-GCM-SHA384 Server public key is 2048 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE No ALPN negotiated SSL-Session:     Protocol  : TLSv1.2     Cipher    : ECDHE-RSA-AES256-GCM-SHA384     Session-ID: 2AF9EFDDB3EA99C101C4E4F99A47CD479D294C15309D7E994ADA21C083D8E096     Session-ID-ctx:     Master-Key: 85646A59B24D5A88080227BD59E328C688910FB0B2E2BAD77D7B1A96F6A9A3ACBF74EEC6C844A7D59527152928580743     PSK identity: None     PSK identity hint: None     SRP username: None     Start Time: 1619562457     Timeout   : 7200 (sec)     Verify return code: 0 (ok)     Extended master secret: yes So even more confusing unless I've goofed something up, sorry. I didn't mess with minssf, maybe that does make a difference. The ciphers are: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256   0xC02F TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384   0xC030 Don't mean to stir up the mud but this may be a question for the NSS team. rob > On Mon, Apr 26, 2021 at 11:50 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> > <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: > >     Then youll need to disable everything except aes256 then I suspect >     ... :( > >     > On 25 Apr 2021, at 11:39, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> >     <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > >     > Well, in this case, I've got to be able to work with regulatory >     requirements so not much I can do there. >     > >     > Trevor >     > >     > On Sat, Apr 24, 2021, 9:03 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> >     <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: >     > >     > >     > > On 24 Apr 2021, at 22:30, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> >     <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > >     > > Hi Marc, >     > > >     > > I was under the impression that it would pick the highest >     supported, but that doesn't seem to be what is happening based on my >     previous example. >     > > >     > > Instead, it seems to just be picking the first compatible, >     regardless of strength. >     > >     > It choose aes128 over 256 because of processing speed, and "strong >     enough". >     > >     > > >     > > Trevor >     > > >     > > On Fri, Apr 23, 2021, 10:03 PM Marc Sauton <msauton(a)redhat.com <mailto:msauton@redhat.com> >     <mailto:msauton@redhat.com <mailto:msauton@redhat.com>>> wrote: >     > > about ciphers order and TLS cipher suite discovery, NSS will >     pick the one with highest strength from the available ciphers, and >     compatible with the TLS client ( handshake) >     > > >     > > you can check the configuration with for example (replace the >     string m1 with an instance name): >     > > dsconf m1 security get >     > > dsconf m1 security ciphers list >     > > dsconf m1 security ciphers list --supported | less >     > > dsconf m1 security ciphers list --enabled >     > > ldapsearch -o ldif-wrap=no -LLLxD "cn=Directory Manager" -W  -b >     cn=encryption,cn=config | less >     > > >     > > and to set ciphers (can be "delicate"): >     > > /usr/lib64/nss/unsupported-tools/listsuites | grep -B1 >     --no-group-separator "Enabled" | less >     > > dsconf m1 security ciphers set xxxxx >     > > >     > > doc ref: >     > > >     https://access.redhat.com/documentation/en-us/red_hat_directory_server/11/html/administration_guide/enabling_tls#setting_encryption_ciphers >     > > >     > > and NSS source: >     > > ./lib/ssl/ssl3con.c >     > > ./lib/ssl/sslenum.c >     > > >     > > >     > > On Fri, Apr 23, 2021 at 4:57 PM Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > William, >     > > >     > > I do apologize! I'll keep that in mind in the future. >     > > >     > > Thanks again for your help, >     > > >     > > Trevor >     > > >     > > On Fri, Apr 23, 2021, 7:50 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> >     <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: >     > > Sorry to call this out, but my name is "William" not "Bill". I >     have personal reasons to dislike being called that name. >     > > >     > > Regardless, happy to help out :) >     > > >     > > > On 23 Apr 2021, at 22:11, Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > > >     > > > Bill and Pierre, >     > > > >     > > > Thanks for the responses! >     > > > >     > > > It sounds like I have to figure out how to configure the NSS >     library for 389-DS specifically. >     > > > >     > > > In EL8+ I know that I can configure the global crypto policy >     but I'm hoping that I can do it for the specific application. I >     haven't found anything in the documentation so far but at least this >     gets me pointed in the right direction. >     > > > >     > > > Thanks, >     > > > >     > > > Trevor >     > > > >     > > > On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier >     &lt;progier(a)redhat.com <mailto:progier@redhat.com> <mailto:progier@redhat.com <mailto:progier@redhat.com>>> wrote: >     > > > Hi Trevor, >     > > > >     > > > I do not think it is possible to specify the cypher order >     negotiation: >     > > >      I am not sure whether TLS protocol allow to specify an >     order when negotiating the cypher, >     > > >      but at 389 level there is no way to specify an order: >     > > > The NSS security layer provides the list of supported cypher >     and 389 use >     > > > nsSSL3Ciphers config parameter to enable/disable theses >     cyphers in the list (without changing the order) >     > > > >     > > >     So my feeling is that if there is an order it is up to the >     different >     > > >      security layer implementations and may differs between >     the applications, >     > > > >     > > > Regards, >     > > >    Pierre >     > > > >     > > > On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > > Hi William, >     > > > >     > > > In terms of the STARTTLS bits (in theory) properly configuring >     your client software mitigates the password leak risk. But this also >     happens with pure (non-RFC) LDAPS connections. >     > > > >     > > > The docs note that minssf applies to the crypto required bits >     as well as the SASL layer. >     > > > >     > > > Ignoring most of that, my issue is that I don't understand why >     I have to nail my client software to ciphers explicitly known by >     389-DS instead of the two negotiating the strongest things possible >     out of the gate. >     > > > >     > > > For instance, if I use AES256 with a minssf=256, everything >     works just fine. >     > > > >     > > > But, if I use AES128:AES256:@STRENGTH (which should sort >     strongest to weakest) then access is denied. >     > > > >     > > > How do I get 389-DS to negotiate the strongest ciphers first >     (regardless of the method)? >     > > > >     > > > Thanks, >     > > > >     > > > Trevor >     > > > >     > > > On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> >     <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: >     > > > Hi there, >     > > > >     > > > > On 22 Apr 2021, at 03:52, Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > > > >     > > > > Hi All, >     > > > > >     > > > > OS Version: CentOS 8 >     > > > > 389-DS Version: 1.4.3.22 from EPEL >     > > > > >     > > > > I have a server set up with minssf=256 and have been >     surprised that either 389-DS, or openssl, does not appear to be >     doing what I would consider a logical TLS negotiation. >     > > > > >     > > > > I had thought that the system would start with the strongest >     cipher and then negotiate down to something that was acceptable. >     > > > > >     > > > > Instead, I'm finding that I have to nail up the ciphers to >     something that the 389-DS server both recognizes and is within the >     expected SSF. >     > > > > >     > > > > Is this expected behavior or do I have something configured >     incorrectly? >     > > > >     > > > That's not what minssf does. >     > > > >     > > > minssf says "during a bind operation, reject if the encryption >     strength used is less than 256 bits or equivalent". >     > > > >     > > > The "bit strength" is arbitrary though, because it's a concept >     from sasl, and generally is very broken. >     > > > >     > > > Remember, minssf does NOT do what you think though! Because >     bind is the *first* message on the wire, the series of operations is >     > > > >     > > > >     > > >    client                   server >     > > > open plain text conn  ->    >     > > >                       <-   accept connection >     > > > send bind on conn     ->    >     > > >                       <-   reject due to minsff too weak. >     > > > >     > > > >     > > > So you have already leaked the password! >     > > > >     > > > >     > > > The only way to ensure this does not occur is to set >     "nsslapd-port: 0" which disables plaintext. Then you *only* use >     ldaps on port 636, which is guarantee encrypted from the start. >     > > > >     > > > It is worth noting that the use of starttls over ldap, does >     *NOT* mitigate this issue, for a similar reason. >     > > > >     > > > >     > > > Caveat: If you are using kerberos/gssapi you can NOT disable >     plaintext ldap due to these protocols attempting to install their >     own encryption layers. >     > > > >     > > > >     > > > Hope that helps, >     > > > >     > > > >     > > > > >     > > > > Thanks, >     > > > > >     > > > > Trevor >     > > > > >     > > > > -- >     > > > > Trevor Vaughan >     > > > > Vice President, Onyx Point, Inc >     > > > > (410) 541-6699 x788 >     > > > > >     > > > > -- This account not approved for unencrypted proprietary >     information -- >     > > > > _______________________________________________ >     > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > — >     > > > Sincerely, >     > > > >     > > > William Brown >     > > > >     > > > Senior Software Engineer, 389 Directory Server >     > > > SUSE Labs, Australia >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > >     > > > -- >     > > > Trevor Vaughan >     > > > Vice President, Onyx Point, Inc >     > > > (410) 541-6699 x788 >     > > > >     > > > -- This account not approved for unencrypted proprietary >     information -- >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > >     > > > -- >     > > > -- >     > > > >     > > > 389 Directory Server Development Team >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > >     > > > -- >     > > > Trevor Vaughan >     > > > Vice President, Onyx Point, Inc >     > > > (410) 541-6699 x788 >     > > > >     > > > -- This account not approved for unencrypted proprietary >     information -- >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > >     > > — >     > > Sincerely, >     > > >     > > William Brown >     > > >     > > Senior Software Engineer, 389 Directory Server >     > > SUSE Labs, Australia >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > >     > — >     > Sincerely, >     > >     > William Brown >     > >     > Senior Software Engineer, 389 Directory Server >     > SUSE Labs, Australia >     > _______________________________________________ >     > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > _______________________________________________ >     > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure > >     — >     Sincerely, > >     William Brown > >     Senior Software Engineer, 389 Directory Server >     SUSE Labs, Australia >     _______________________________________________ >     389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines >     List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure > > > > -- > Trevor Vaughan > Vice President, Onyx Point, Inc > (410) 541-6699 x788 > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information --

So, I just ran this test with selfserv as you have above and everything worked as expected with s_client. It seems to be something in 389 itself. On Tue, Apr 27, 2021 at 6:32 PM Rob Crittenden <rcritten(a)redhat.com&gt; wrote: > Trevor Vaughan wrote: > > Going full circle on this, I confirmed using s_client that what I was > > seeing was indeed happening but not for the reason that I thought it > was. > > > > Given that the min_ssf is 256, the connection requires a 256-bit cipher > > and hash to communicate with the server. > > > > Strangely, the internal strength logic on the 389-DS side appears to > > pick ECDHE-RSA-AES128-GCM-SHA256 *before* ECDHE-RSA-AES256-GCM-SHA384. > > Likewise, if I add any of the AES128 ciphers to the list after the > > AES256 ciphers, one of the 128-bit ciphers will be chosen first. This > > seems incorrect given that the server should be using the strongest > > cipher suite available if possible. > > > > The client cipher order preference is completely ignored (which is > fine). > > > > As pointed out in the last response, I did indeed need to explicitly > > enable only the 256-bit+ hash/cipher combinations in the > > confusingly-named nsSSL3Ciphers attribute. > > > > After figuring this out and dumping the internal supported cipher list, > > I can confirm that the ciphers in the nsSSL3Ciphers list are the only > > ones that are presented to the client. > > > > While not ideal, this does provide a solution to the issue where I don't > > have to tell all system users that they need to nail up the cipher lists > > on the client side in order for things to function properly. > > > > But that leaves me with two questions: > > > > 1) Why, when the nsslapd-minssf option is set in the global > > configuration, does 389-DS not automatically prune any options that will > > result in an unsuccessful connection. > > > > 2) Why is the internal cipher sorting order choosing weaker cipher > > suites before stronger ones? > > I'm pretty sure that 389-ds still uses NSS for server-side crypto and > unless something has changed NSS doesn't do cipher sorting. It picks the > "best" for you. AFAIR the server has no say in the matter. > > But, as a goof I used a pure NSS server tool to see what happens and it > picked the expected cipher. > > Enable your two ciphers (in hex form): > > $ /usr/lib64/nss/unsupported-tools/selfserv -n Server-Cert -d > /etc/dirsrv/slapd-EXAMPLE-TEST/ -p 8389 -f > /etc/dirsrv/slapd-EXAMPLE-TEST/pwdfile.txt -c :C02F -c :C030 -v -V > tls1.2:tls1.2 > > run s_client: > > New, TLSv1.2, Cipher is ECDHE-RSA-AES256-GCM-SHA384 > Server public key is 2048 bit > Secure Renegotiation IS supported > Compression: NONE > Expansion: NONE > No ALPN negotiated > SSL-Session: > Protocol : TLSv1.2 > Cipher : ECDHE-RSA-AES256-GCM-SHA384 > Session-ID: > 2AF9EFDDB3EA99C101C4E4F99A47CD479D294C15309D7E994ADA21C083D8E096 > Session-ID-ctx: > Master-Key: > > 85646A59B24D5A88080227BD59E328C688910FB0B2E2BAD77D7B1A96F6A9A3ACBF74EEC6C844A7D59527152928580743 > PSK identity: None > PSK identity hint: None > SRP username: None > Start Time: 1619562457 > Timeout : 7200 (sec) > Verify return code: 0 (ok) > Extended master secret: yes > > So even more confusing unless I've goofed something up, sorry. I didn't > mess with minssf, maybe that does make a difference. > > The ciphers are: > > TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 0xC02F > TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 0xC030 > > Don't mean to stir up the mud but this may be a question for the NSS team. > > rob > > > On Mon, Apr 26, 2021 at 11:50 PM William Brown <wbrown(a)suse.de > > <mailto:wbrown@suse.de>> wrote: > > > > Then youll need to disable everything except aes256 then I suspect > > ... :( > > > > > On 25 Apr 2021, at 11:39, Trevor Vaughan <tvaughan(a)onyxpoint.com > > <mailto:tvaughan@onyxpoint.com>> wrote: > > > > > > Well, in this case, I've got to be able to work with regulatory > > requirements so not much I can do there. > > > > > > Trevor > > > > > > On Sat, Apr 24, 2021, 9:03 PM William Brown <wbrown(a)suse.de > > <mailto:wbrown@suse.de>> wrote: > > > > > > > > > > On 24 Apr 2021, at 22:30, Trevor Vaughan < > tvaughan(a)onyxpoint.com > > <mailto:tvaughan@onyxpoint.com>> wrote: > > > > > > > > Hi Marc, > > > > > > > > I was under the impression that it would pick the highest > > supported, but that doesn't seem to be what is happening based on my > > previous example. > > > > > > > > Instead, it seems to just be picking the first compatible, > > regardless of strength. > > > > > > It choose aes128 over 256 because of processing speed, and "strong > > enough". > > > > > > > > > > > Trevor > > > > > > > > On Fri, Apr 23, 2021, 10:03 PM Marc Sauton <msauton(a)redhat.com > > <mailto:msauton@redhat.com>> wrote: > > > > about ciphers order and TLS cipher suite discovery, NSS will > > pick the one with highest strength from the available ciphers, and > > compatible with the TLS client ( handshake) > > > > > > > > you can check the configuration with for example (replace the > > string m1 with an instance name): > > > > dsconf m1 security get > > > > dsconf m1 security ciphers list > > > > dsconf m1 security ciphers list --supported | less > > > > dsconf m1 security ciphers list --enabled > > > > ldapsearch -o ldif-wrap=no -LLLxD "cn=Directory Manager" -W -b > > cn=encryption,cn=config | less > > > > > > > > and to set ciphers (can be "delicate"): > > > > /usr/lib64/nss/unsupported-tools/listsuites | grep -B1 > > --no-group-separator "Enabled" | less > > > > dsconf m1 security ciphers set xxxxx > > > > > > > > doc ref: > > > > > > > https://access.redhat.com/documentation/en-us/red_hat_directory_server/11... > > > > > > > > and NSS source: > > > > ./lib/ssl/ssl3con.c > > > > ./lib/ssl/sslenum.c > > > > > > > > > > > > On Fri, Apr 23, 2021 at 4:57 PM Trevor Vaughan > > <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > > William, > > > > > > > > I do apologize! I'll keep that in mind in the future. > > > > > > > > Thanks again for your help, > > > > > > > > Trevor > > > > > > > > On Fri, Apr 23, 2021, 7:50 PM William Brown <wbrown(a)suse.de > > <mailto:wbrown@suse.de>> wrote: > > > > Sorry to call this out, but my name is "William" not "Bill". I > > have personal reasons to dislike being called that name. > > > > > > > > Regardless, happy to help out :) > > > > > > > > > On 23 Apr 2021, at 22:11, Trevor Vaughan > > <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > > > > > > > > Bill and Pierre, > > > > > > > > > > Thanks for the responses! > > > > > > > > > > It sounds like I have to figure out how to configure the NSS > > library for 389-DS specifically. > > > > > > > > > > In EL8+ I know that I can configure the global crypto policy > > but I'm hoping that I can do it for the specific application. I > > haven't found anything in the documentation so far but at least this > > gets me pointed in the right direction. > > > > > > > > > > Thanks, > > > > > > > > > > Trevor > > > > > > > > > > On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier > > <progier(a)redhat.com <mailto:progier@redhat.com>> wrote: > > > > > Hi Trevor, > > > > > > > > > > I do not think it is possible to specify the cypher order > > negotiation: > > > > > I am not sure whether TLS protocol allow to specify an > > order when negotiating the cypher, > > > > > but at 389 level there is no way to specify an order: > > > > > The NSS security layer provides the list of supported cypher > > and 389 use > > > > > nsSSL3Ciphers config parameter to enable/disable theses > > cyphers in the list (without changing the order) > > > > > > > > > > So my feeling is that if there is an order it is up to the > > different > > > > > security layer implementations and may differs between > > the applications, > > > > > > > > > > Regards, > > > > > Pierre > > > > > > > > > > On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan > > <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > > > Hi William, > > > > > > > > > > In terms of the STARTTLS bits (in theory) properly configuring > > your client software mitigates the password leak risk. But this also > > happens with pure (non-RFC) LDAPS connections. > > > > > > > > > > The docs note that minssf applies to the crypto required bits > > as well as the SASL layer. > > > > > > > > > > Ignoring most of that, my issue is that I don't understand why > > I have to nail my client software to ciphers explicitly known by > > 389-DS instead of the two negotiating the strongest things possible > > out of the gate. > > > > > > > > > > For instance, if I use AES256 with a minssf=256, everything > > works just fine. > > > > > > > > > > But, if I use AES128:AES256:@STRENGTH (which should sort > > strongest to weakest) then access is denied. > > > > > > > > > > How do I get 389-DS to negotiate the strongest ciphers first > > (regardless of the method)? > > > > > > > > > > Thanks, > > > > > > > > > > Trevor > > > > > > > > > > On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de > > <mailto:wbrown@suse.de>> wrote: > > > > > Hi there, > > > > > > > > > > > On 22 Apr 2021, at 03:52, Trevor Vaughan > > <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: > > > > > > > > > > > > Hi All, > > > > > > > > > > > > OS Version: CentOS 8 > > > > > > 389-DS Version: 1.4.3.22 from EPEL > > > > > > > > > > > > I have a server set up with minssf=256 and have been > > surprised that either 389-DS, or openssl, does not appear to be > > doing what I would consider a logical TLS negotiation. > > > > > > > > > > > > I had thought that the system would start with the strongest > > cipher and then negotiate down to something that was acceptable. > > > > > > > > > > > > Instead, I'm finding that I have to nail up the ciphers to > > something that the 389-DS server both recognizes and is within the > > expected SSF. > > > > > > > > > > > > Is this expected behavior or do I have something configured > > incorrectly? > > > > > > > > > > That's not what minssf does. > > > > > > > > > > minssf says "during a bind operation, reject if the encryption > > strength used is less than 256 bits or equivalent". > > > > > > > > > > The "bit strength" is arbitrary though, because it's a concept > > from sasl, and generally is very broken. > > > > > > > > > > Remember, minssf does NOT do what you think though! Because > > bind is the *first* message on the wire, the series of operations is > > > > > > > > > > > > > > > client server > > > > > open plain text conn -> > > > > > <- accept connection > > > > > send bind on conn -> > > > > > <- reject due to minsff too weak. > > > > > > > > > > > > > > > So you have already leaked the password! > > > > > > > > > > > > > > > The only way to ensure this does not occur is to set > > "nsslapd-port: 0" which disables plaintext. Then you *only* use > > ldaps on port 636, which is guarantee encrypted from the start. > > > > > > > > > > It is worth noting that the use of starttls over ldap, does > > *NOT* mitigate this issue, for a similar reason. > > > > > > > > > > > > > > > Caveat: If you are using kerberos/gssapi you can NOT disable > > plaintext ldap due to these protocols attempting to install their > > own encryption layers. > > > > > > > > > > > > > > > Hope that helps, > > > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > > > Trevor > > > > > > > > > > > > -- > > > > > > Trevor Vaughan > > > > > > Vice President, Onyx Point, Inc > > > > > > (410) 541-6699 x788 > > > > > > > > > > > > -- This account not approved for unencrypted proprietary > > information -- > > > > > > _______________________________________________ > > > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > > > > > > > — > > > > > Sincerely, > > > > > > > > > > William Brown > > > > > > > > > > Senior Software Engineer, 389 Directory Server > > > > > SUSE Labs, Australia > > > > > _______________________________________________ > > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > > > > > > > > > > > > -- > > > > > Trevor Vaughan > > > > > Vice President, Onyx Point, Inc > > > > > (410) 541-6699 x788 > > > > > > > > > > -- This account not approved for unencrypted proprietary > > information -- > > > > > _______________________________________________ > > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > > > > > > > > > > > > -- > > > > > -- > > > > > > > > > > 389 Directory Server Development Team > > > > > _______________________________________________ > > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > > > > > > > > > > > > -- > > > > > Trevor Vaughan > > > > > Vice President, Onyx Point, Inc > > > > > (410) 541-6699 x788 > > > > > > > > > > -- This account not approved for unencrypted proprietary > > information -- > > > > > _______________________________________________ > > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > > > > > — > > > > Sincerely, > > > > > > > > William Brown > > > > > > > > Senior Software Engineer, 389 Directory Server > > > > SUSE Labs, Australia > > > > _______________________________________________ > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > _______________________________________________ > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > _______________________________________________ > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > _______________________________________________ > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > > > — > > > Sincerely, > > > > > > William Brown > > > > > > Senior Software Engineer, 389 Directory Server > > > SUSE Labs, Australia > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > _______________________________________________ > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > > List Guidelines: > > https://fedoraproject.org/wiki/Mailing_list_guidelines > > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > — > > Sincerely, > > > > William Brown > > > > Senior Software Engineer, 389 Directory Server > > SUSE Labs, Australia > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > <mailto:389-users@lists.fedoraproject.org> > > To unsubscribe send an email to > > 389-users-leave(a)lists.fedoraproject.org > > <mailto:389-users-leave@lists.fedoraproject.org> > > Fedora Code of Conduct: > > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: > https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > > > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: > > https://pagure.io/fedora-infrastructure > > > > > > > > -- > > Trevor Vaughan > > Vice President, Onyx Point, Inc > > (410) 541-6699 x788 > > > > -- This account not approved for unencrypted proprietary information -- > > > > _______________________________________________ > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org > > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org > > Fedora Code of Conduct: > https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > > List Archives: > https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > > Do not reply to spam on the list, report it: > https://pagure.io/fedora-infrastructure > > > > -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information --

Interestingly, if I remove the cipher specification, I get the result of ECDHE-RSA-AES128-GCM-SHA256. Can you see if this also happens with your version of nss?

Thanks, Trevor On Wed, Apr 28, 2021 at 8:27 AM Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com>> wrote: So, I just ran this test with selfserv as you have above and everything worked as expected with s_client. It seems to be something in 389 itself. On Tue, Apr 27, 2021 at 6:32 PM Rob Crittenden <rcritten(a)redhat.com <mailto:rcritten@redhat.com>> wrote: Trevor Vaughan wrote: > Going full circle on this, I confirmed using s_client that what I was > seeing was indeed happening but not for the reason that I thought it was. > > Given that the min_ssf is 256, the connection requires a 256-bit cipher > and hash to communicate with the server. > > Strangely, the internal strength logic on the 389-DS side appears to > pick ECDHE-RSA-AES128-GCM-SHA256 *before* ECDHE-RSA-AES256-GCM-SHA384. > Likewise, if I add any of the AES128 ciphers to the list after the > AES256 ciphers, one of the 128-bit ciphers will be chosen first. This > seems incorrect given that the server should be using the strongest > cipher suite available if possible. > > The client cipher order preference is completely ignored (which is fine). > > As pointed out in the last response, I did indeed need to explicitly > enable only the 256-bit+ hash/cipher combinations in the > confusingly-named nsSSL3Ciphers attribute. > > After figuring this out and dumping the internal supported cipher list, > I can confirm that the ciphers in the nsSSL3Ciphers list are the only > ones that are presented to the client. > > While not ideal, this does provide a solution to the issue where I don't > have to tell all system users that they need to nail up the cipher lists > on the client side in order for things to function properly. > > But that leaves me with two questions: > > 1) Why, when the nsslapd-minssf option is set in the global > configuration, does 389-DS not automatically prune any options that will > result in an unsuccessful connection. > > 2) Why is the internal cipher sorting order choosing weaker cipher > suites before stronger ones? I'm pretty sure that 389-ds still uses NSS for server-side crypto and unless something has changed NSS doesn't do cipher sorting. It picks the "best" for you. AFAIR the server has no say in the matter. But, as a goof I used a pure NSS server tool to see what happens and it picked the expected cipher. Enable your two ciphers (in hex form): $ /usr/lib64/nss/unsupported-tools/selfserv -n Server-Cert -d /etc/dirsrv/slapd-EXAMPLE-TEST/ -p 8389 -f /etc/dirsrv/slapd-EXAMPLE-TEST/pwdfile.txt -c :C02F -c :C030 -v -V tls1.2:tls1.2 run s_client: New, TLSv1.2, Cipher is ECDHE-RSA-AES256-GCM-SHA384 Server public key is 2048 bit Secure Renegotiation IS supported Compression: NONE Expansion: NONE No ALPN negotiated SSL-Session:     Protocol  : TLSv1.2     Cipher    : ECDHE-RSA-AES256-GCM-SHA384     Session-ID: 2AF9EFDDB3EA99C101C4E4F99A47CD479D294C15309D7E994ADA21C083D8E096     Session-ID-ctx:     Master-Key: 85646A59B24D5A88080227BD59E328C688910FB0B2E2BAD77D7B1A96F6A9A3ACBF74EEC6C844A7D59527152928580743     PSK identity: None     PSK identity hint: None     SRP username: None     Start Time: 1619562457     Timeout   : 7200 (sec)     Verify return code: 0 (ok)     Extended master secret: yes So even more confusing unless I've goofed something up, sorry. I didn't mess with minssf, maybe that does make a difference. The ciphers are: TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256   0xC02F TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384   0xC030 Don't mean to stir up the mud but this may be a question for the NSS team. rob > On Mon, Apr 26, 2021 at 11:50 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> > <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: > >     Then youll need to disable everything except aes256 then I suspect >     ... :( > >     > On 25 Apr 2021, at 11:39, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> >     <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > >     > Well, in this case, I've got to be able to work with regulatory >     requirements so not much I can do there. >     > >     > Trevor >     > >     > On Sat, Apr 24, 2021, 9:03 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> >     <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: >     > >     > >     > > On 24 Apr 2021, at 22:30, Trevor Vaughan <tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> >     <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > >     > > Hi Marc, >     > > >     > > I was under the impression that it would pick the highest >     supported, but that doesn't seem to be what is happening based on my >     previous example. >     > > >     > > Instead, it seems to just be picking the first compatible, >     regardless of strength. >     > >     > It choose aes128 over 256 because of processing speed, and "strong >     enough". >     > >     > > >     > > Trevor >     > > >     > > On Fri, Apr 23, 2021, 10:03 PM Marc Sauton <msauton(a)redhat.com <mailto:msauton@redhat.com> >     <mailto:msauton@redhat.com <mailto:msauton@redhat.com>>> wrote: >     > > about ciphers order and TLS cipher suite discovery, NSS will >     pick the one with highest strength from the available ciphers, and >     compatible with the TLS client ( handshake) >     > > >     > > you can check the configuration with for example (replace the >     string m1 with an instance name): >     > > dsconf m1 security get >     > > dsconf m1 security ciphers list >     > > dsconf m1 security ciphers list --supported | less >     > > dsconf m1 security ciphers list --enabled >     > > ldapsearch -o ldif-wrap=no -LLLxD "cn=Directory Manager" -W  -b >     cn=encryption,cn=config | less >     > > >     > > and to set ciphers (can be "delicate"): >     > > /usr/lib64/nss/unsupported-tools/listsuites | grep -B1 >     --no-group-separator "Enabled" | less >     > > dsconf m1 security ciphers set xxxxx >     > > >     > > doc ref: >     > > >     https://access.redhat.com/documentation/en-us/red_hat_directory_server/11/html/administration_guide/enabling_tls#setting_encryption_ciphers >     > > >     > > and NSS source: >     > > ./lib/ssl/ssl3con.c >     > > ./lib/ssl/sslenum.c >     > > >     > > >     > > On Fri, Apr 23, 2021 at 4:57 PM Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > William, >     > > >     > > I do apologize! I'll keep that in mind in the future. >     > > >     > > Thanks again for your help, >     > > >     > > Trevor >     > > >     > > On Fri, Apr 23, 2021, 7:50 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> >     <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: >     > > Sorry to call this out, but my name is "William" not "Bill". I >     have personal reasons to dislike being called that name. >     > > >     > > Regardless, happy to help out :) >     > > >     > > > On 23 Apr 2021, at 22:11, Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > > >     > > > Bill and Pierre, >     > > > >     > > > Thanks for the responses! >     > > > >     > > > It sounds like I have to figure out how to configure the NSS >     library for 389-DS specifically. >     > > > >     > > > In EL8+ I know that I can configure the global crypto policy >     but I'm hoping that I can do it for the specific application. I >     haven't found anything in the documentation so far but at least this >     gets me pointed in the right direction. >     > > > >     > > > Thanks, >     > > > >     > > > Trevor >     > > > >     > > > On Fri, Apr 23, 2021 at 4:42 AM Pierre Rogier >     &lt;progier(a)redhat.com <mailto:progier@redhat.com> <mailto:progier@redhat.com <mailto:progier@redhat.com>>> wrote: >     > > > Hi Trevor, >     > > > >     > > > I do not think it is possible to specify the cypher order >     negotiation: >     > > >      I am not sure whether TLS protocol allow to specify an >     order when negotiating the cypher, >     > > >      but at 389 level there is no way to specify an order: >     > > > The NSS security layer provides the list of supported cypher >     and 389 use >     > > > nsSSL3Ciphers config parameter to enable/disable theses >     cyphers in the list (without changing the order) >     > > > >     > > >     So my feeling is that if there is an order it is up to the >     different >     > > >      security layer implementations and may differs between >     the applications, >     > > > >     > > > Regards, >     > > >    Pierre >     > > > >     > > > On Thu, Apr 22, 2021 at 7:28 PM Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > > Hi William, >     > > > >     > > > In terms of the STARTTLS bits (in theory) properly configuring >     your client software mitigates the password leak risk. But this also >     happens with pure (non-RFC) LDAPS connections. >     > > > >     > > > The docs note that minssf applies to the crypto required bits >     as well as the SASL layer. >     > > > >     > > > Ignoring most of that, my issue is that I don't understand why >     I have to nail my client software to ciphers explicitly known by >     389-DS instead of the two negotiating the strongest things possible >     out of the gate. >     > > > >     > > > For instance, if I use AES256 with a minssf=256, everything >     works just fine. >     > > > >     > > > But, if I use AES128:AES256:@STRENGTH (which should sort >     strongest to weakest) then access is denied. >     > > > >     > > > How do I get 389-DS to negotiate the strongest ciphers first >     (regardless of the method)? >     > > > >     > > > Thanks, >     > > > >     > > > Trevor >     > > > >     > > > On Wed, Apr 21, 2021 at 7:34 PM William Brown <wbrown(a)suse.de <mailto:wbrown@suse.de> >     <mailto:wbrown@suse.de <mailto:wbrown@suse.de>>> wrote: >     > > > Hi there, >     > > > >     > > > > On 22 Apr 2021, at 03:52, Trevor Vaughan >     &lt;tvaughan(a)onyxpoint.com <mailto:tvaughan@onyxpoint.com> <mailto:tvaughan@onyxpoint.com <mailto:tvaughan@onyxpoint.com>>> wrote: >     > > > > >     > > > > Hi All, >     > > > > >     > > > > OS Version: CentOS 8 >     > > > > 389-DS Version: 1.4.3.22 from EPEL >     > > > > >     > > > > I have a server set up with minssf=256 and have been >     surprised that either 389-DS, or openssl, does not appear to be >     doing what I would consider a logical TLS negotiation. >     > > > > >     > > > > I had thought that the system would start with the strongest >     cipher and then negotiate down to something that was acceptable. >     > > > > >     > > > > Instead, I'm finding that I have to nail up the ciphers to >     something that the 389-DS server both recognizes and is within the >     expected SSF. >     > > > > >     > > > > Is this expected behavior or do I have something configured >     incorrectly? >     > > > >     > > > That's not what minssf does. >     > > > >     > > > minssf says "during a bind operation, reject if the encryption >     strength used is less than 256 bits or equivalent". >     > > > >     > > > The "bit strength" is arbitrary though, because it's a concept >     from sasl, and generally is very broken. >     > > > >     > > > Remember, minssf does NOT do what you think though! Because >     bind is the *first* message on the wire, the series of operations is >     > > > >     > > > >     > > >    client                   server >     > > > open plain text conn  ->    >     > > >                       <-   accept connection >     > > > send bind on conn     ->    >     > > >                       <-   reject due to minsff too weak. >     > > > >     > > > >     > > > So you have already leaked the password! >     > > > >     > > > >     > > > The only way to ensure this does not occur is to set >     "nsslapd-port: 0" which disables plaintext. Then you *only* use >     ldaps on port 636, which is guarantee encrypted from the start. >     > > > >     > > > It is worth noting that the use of starttls over ldap, does >     *NOT* mitigate this issue, for a similar reason. >     > > > >     > > > >     > > > Caveat: If you are using kerberos/gssapi you can NOT disable >     plaintext ldap due to these protocols attempting to install their >     own encryption layers. >     > > > >     > > > >     > > > Hope that helps, >     > > > >     > > > >     > > > > >     > > > > Thanks, >     > > > > >     > > > > Trevor >     > > > > >     > > > > -- >     > > > > Trevor Vaughan >     > > > > Vice President, Onyx Point, Inc >     > > > > (410) 541-6699 x788 >     > > > > >     > > > > -- This account not approved for unencrypted proprietary >     information -- >     > > > > _______________________________________________ >     > > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > — >     > > > Sincerely, >     > > > >     > > > William Brown >     > > > >     > > > Senior Software Engineer, 389 Directory Server >     > > > SUSE Labs, Australia >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > >     > > > -- >     > > > Trevor Vaughan >     > > > Vice President, Onyx Point, Inc >     > > > (410) 541-6699 x788 >     > > > >     > > > -- This account not approved for unencrypted proprietary >     information -- >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > >     > > > -- >     > > > -- >     > > > >     > > > 389 Directory Server Development Team >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > > >     > > > >     > > > -- >     > > > Trevor Vaughan >     > > > Vice President, Onyx Point, Inc >     > > > (410) 541-6699 x788 >     > > > >     > > > -- This account not approved for unencrypted proprietary >     information -- >     > > > _______________________________________________ >     > > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > >     > > — >     > > Sincerely, >     > > >     > > William Brown >     > > >     > > Senior Software Engineer, 389 Directory Server >     > > SUSE Labs, Australia >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > > _______________________________________________ >     > > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > >     > — >     > Sincerely, >     > >     > William Brown >     > >     > Senior Software Engineer, 389 Directory Server >     > SUSE Labs, Australia >     > _______________________________________________ >     > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure >     > _______________________________________________ >     > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     > To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     > Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     > List Guidelines: >     https://fedoraproject.org/wiki/Mailing_list_guidelines >     > List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     > Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure > >     — >     Sincerely, > >     William Brown > >     Senior Software Engineer, 389 Directory Server >     SUSE Labs, Australia >     _______________________________________________ >     389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> >     <mailto:389-users@lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org>> >     To unsubscribe send an email to >     389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> >     <mailto:389-users-leave@lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org>> >     Fedora Code of Conduct: >     https://docs.fedoraproject.org/en-US/project/code-of-conduct/ >     List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines >     List Archives: >     https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproject.org >     Do not reply to spam on the list, report it: >     https://pagure.io/fedora-infrastructure > > > > -- > Trevor Vaughan > Vice President, Onyx Point, Inc > (410) 541-6699 x788 > > -- This account not approved for unencrypted proprietary information -- > > _______________________________________________ > 389-users mailing list -- 389-users(a)lists.fedoraproject.org <mailto:389-users@lists.fedoraproject.org> > To unsubscribe send an email to 389-users-leave(a)lists.fedoraproject.org <mailto:389-users-leave@lists.fedoraproject.org> > Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ > List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines > List Archives: https://lists.fedoraproject.org/archives/list/389-users@lists.fedoraproje... > Do not reply to spam on the list, report it: https://pagure.io/fedora-infrastructure > -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information -- -- Trevor Vaughan Vice President, Onyx Point, Inc (410) 541-6699 x788 -- This account not approved for unencrypted proprietary information --