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-rw-r--r--src/util/crypto/nss/nss_hmac_sha1.c88
1 files changed, 88 insertions, 0 deletions
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 000000000..6faa09aee
--- /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;
+}