>From c58832e7377d02aa8eedc5a1619f5356a6db7e0a Mon Sep 17 00:00:00 2001
From: Jan Cholasta <jcholast@redhat.com>
Date: Tue, 17 Apr 2012 11:03:23 -0400
Subject: [PATCH 1/2] UTIL: Add HMAC-SHA-1 function

---
 Makefile.am                                  |    2 +
 src/tests/crypto-tests.c                     |   35 ++++++++++
 src/util/crypto/libcrypto/crypto_hmac_sha1.c |   31 +++++++++
 src/util/crypto/nss/nss_hmac_sha1.c          |   88 ++++++++++++++++++++++++++
 src/util/crypto/sss_crypto.h                 |    8 +++
 5 files changed, 164 insertions(+), 0 deletions(-)
 create mode 100644 src/util/crypto/libcrypto/crypto_hmac_sha1.c
 create mode 100644 src/util/crypto/nss/nss_hmac_sha1.c

diff --git a/Makefile.am b/Makefile.am
index 8d2c8ce..831a744 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -153,6 +153,7 @@ noinst_LTLIBRARIES = \
 
 if HAVE_NSS
     SSS_CRYPT_SOURCES = src/util/crypto/nss/nss_base64.c \
+                        src/util/crypto/nss/nss_hmac_sha1.c \
                         src/util/crypto/nss/nss_sha512crypt.c \
                         src/util/crypto/nss/nss_obfuscate.c \
                         src/util/crypto/nss/nss_util.c
@@ -160,6 +161,7 @@ if HAVE_NSS
     SSS_CRYPT_LIBS = $(NSS_LIBS)
 else
     SSS_CRYPT_SOURCES = src/util/crypto/libcrypto/crypto_base64.c \
+                        src/util/crypto/libcrypto/crypto_hmac_sha1.c \
                         src/util/crypto/libcrypto/crypto_sha512crypt.c \
                         src/util/crypto/libcrypto/crypto_obfuscate.c
     SSS_CRYPT_CFLAGS = $(CRYPTO_CFLAGS)
diff --git a/src/tests/crypto-tests.c b/src/tests/crypto-tests.c
index ba58466..ebff938 100644
--- a/src/tests/crypto-tests.c
+++ b/src/tests/crypto-tests.c
@@ -91,6 +91,40 @@ START_TEST(test_encrypt_decrypt)
 }
 END_TEST
 
+START_TEST(test_hmac_sha1)
+{
+    const char *message = "test message";
+    const char *keys[] = {
+        "short",
+        "proper6789012345678901234567890123456789012345678901234567890123",
+        "longlonglonglonglonglonglonglonglonglonglonglonglonglonglonglonglong",
+        NULL };
+    const char *results[] = {
+        "\x2b\x27\x53\x07\x17\xd8\xc0\x8f\x97\x27\xdd\xb3\xec\x41\xd8\xa3\x94\x97\xaa\x35",
+        "\x37\xe7\x0a\x6f\x71\x0b\xa9\x93\x81\x53\x8f\x5c\x06\x83\x44\x2f\xc9\x41\xe3\xed",
+        "\xbd\x99\xa7\x7f\xfc\x5e\xde\x04\x32\x7f\x7b\x71\x4d\xc0\x3f\x51\x2d\x25\x01\x28",
+        NULL };
+    char out[SSS_SHA1_LENGTH];
+    int ret, expected;
+    int i;
+
+#ifdef HAVE_NSS
+    expected = EOK;
+#elif HAVE_LIBCRYPTO
+    expected = ENOSYS;
+#else
+#error Unknown crypto back end
+#endif
+
+    for (i = 0; keys[i]; i++) {
+        ret = sss_hmac_sha1(keys[i], strlen(keys[i]), message, strlen(message),
+                            out);
+        fail_if(ret != expected);
+        fail_if(ret == EOK && memcmp(out, results[i], SSS_SHA1_LENGTH) != 0);
+    }
+}
+END_TEST
+
 Suite *crypto_suite(void)
 {
     Suite *s = suite_create("sss_crypto");
@@ -102,6 +136,7 @@ Suite *crypto_suite(void)
     tcase_add_test(tc, test_nss_init);
 #endif
     tcase_add_test(tc, test_encrypt_decrypt);
+    tcase_add_test(tc, test_hmac_sha1);
     /* Add all test cases to the test suite */
     suite_add_tcase(s, tc);
 
diff --git a/src/util/crypto/libcrypto/crypto_hmac_sha1.c b/src/util/crypto/libcrypto/crypto_hmac_sha1.c
new file mode 100644
index 0000000..32acd25
--- /dev/null
+++ b/src/util/crypto/libcrypto/crypto_hmac_sha1.c
@@ -0,0 +1,31 @@
+/*
+    Authors:
+        Jan Cholasta <jcholast@redhat.com>
+
+    Copyright (C) 2012 Red Hat
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "util/util.h"
+
+int sss_hmac_sha1(const unsigned char *key,
+                  size_t key_len,
+                  const unsigned char *in,
+                  size_t in_len,
+                  unsigned char *out)
+{
+    DEBUG(SSSDBG_CRIT_FAILURE, ("sss_hmac_sha1 not implemented.\n"));
+    return ENOSYS;
+}
diff --git a/src/util/crypto/nss/nss_hmac_sha1.c b/src/util/crypto/nss/nss_hmac_sha1.c
new file mode 100644
index 0000000..6faa09a
--- /dev/null
+++ b/src/util/crypto/nss/nss_hmac_sha1.c
@@ -0,0 +1,88 @@
+/*
+    Authors:
+        Jan Cholasta <jcholast@redhat.com>
+
+    Copyright (C) 2012 Red Hat
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/*
+    NSS does not provide public API for HMAC, so we implement it ourselves.
+
+    See RFC 2104 for details on the algorithm.
+*/
+
+#include "util/util.h"
+#include "util/crypto/sss_crypto.h"
+#include "util/crypto/nss/nss_util.h"
+
+#include <sechash.h>
+
+#define HMAC_SHA1_BLOCKSIZE 64
+
+int sss_hmac_sha1(const unsigned char *key,
+                  size_t key_len,
+                  const unsigned char *in,
+                  size_t in_len,
+                  unsigned char *out)
+{
+    int ret;
+    unsigned char ikey[HMAC_SHA1_BLOCKSIZE], okey[HMAC_SHA1_BLOCKSIZE];
+    size_t i;
+    HASHContext *sha1;
+    unsigned char hash[SSS_SHA1_LENGTH];
+    unsigned int res_len;
+
+    ret = nspr_nss_init();
+    if (ret != EOK) {
+        return ret;
+    }
+
+    sha1 = HASH_Create(HASH_AlgSHA1);
+    if (!sha1) {
+        return ENOMEM;
+    }
+
+    if (key_len > HMAC_SHA1_BLOCKSIZE) {
+        /* keys longer than blocksize are shortened */
+        HASH_Begin(sha1);
+        HASH_Update(sha1, key, key_len);
+        HASH_End(sha1, ikey, &res_len, SSS_SHA1_LENGTH);
+        memset(ikey + SSS_SHA1_LENGTH, 0, HMAC_SHA1_BLOCKSIZE - SSS_SHA1_LENGTH);
+    } else {
+        /* keys shorter than blocksize are zero-padded */
+        memcpy(ikey, key, key_len);
+        memset(ikey + key_len, 0, HMAC_SHA1_BLOCKSIZE - key_len);
+    }
+
+    /* HMAC(key, msg) = HASH(key XOR opad, HASH(key XOR ipad, msg)) */
+    for (i = 0; i < HMAC_SHA1_BLOCKSIZE; i++) {
+        okey[i] = ikey[i] ^ 0x5c;
+        ikey[i] ^= 0x36;
+    }
+
+    HASH_Begin(sha1);
+    HASH_Update(sha1, ikey, HMAC_SHA1_BLOCKSIZE);
+    HASH_Update(sha1, in, in_len);
+    HASH_End(sha1, hash, &res_len, SSS_SHA1_LENGTH);
+
+    HASH_Begin(sha1);
+    HASH_Update(sha1, okey, HMAC_SHA1_BLOCKSIZE);
+    HASH_Update(sha1, hash, SSS_SHA1_LENGTH);
+    HASH_End(sha1, out, &res_len, SSS_SHA1_LENGTH);
+
+    HASH_Destroy(sha1);
+
+    return EOK;
+}
diff --git a/src/util/crypto/sss_crypto.h b/src/util/crypto/sss_crypto.h
index 7b3e5e0..5b40ecf 100644
--- a/src/util/crypto/sss_crypto.h
+++ b/src/util/crypto/sss_crypto.h
@@ -19,6 +19,14 @@ unsigned char *sss_base64_decode(TALLOC_CTX *mem_ctx,
                                  const char *in,
                                  size_t *outsize);
 
+#define SSS_SHA1_LENGTH 20
+
+int sss_hmac_sha1(const unsigned char *key,
+                  size_t key_len,
+                  const unsigned char *in,
+                  size_t in_len,
+                  unsigned char *out);
+
 int sss_password_encrypt(TALLOC_CTX *mem_ctx, const char *password, int plen,
                          enum obfmethod meth, char **obfpwd);
 
-- 
1.7.7.6

