1 files changed, 61 insertions, 0 deletions
diff --git a/comm/third_party/libotr/toolkit/sha1hmac.c b/comm/third_party/libotr/toolkit/sha1hmac.c
new file mode 100644
index 0000000000..7cf82d6a10
--- /dev/null
+++ b/comm/third_party/libotr/toolkit/sha1hmac.c
@@ -0,0 +1,61 @@
+/*
+ *  Off-the-Record Messaging Toolkit
+ *  Copyright (C) 2004-2012  Ian Goldberg, Chris Alexander, Nikita Borisov
+ *                           <otr@cypherpunks.ca>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of version 2 of the GNU General Public License as
+ *  published by the Free Software Foundation.
+ *
+ *  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, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/* system headers */
+#include <stdio.h>
+#include <stdlib.h>
+
+/* libgcrypt headers */
+#include <gcrypt.h>
+
+/* Implementation of SHA1-HMAC.  We're rolling our own just to
+ * double-check that the calls libotr makes to libgcrypt are in fact
+ * doing the right thing. */
+void sha1hmac(unsigned char digest[20], unsigned char key[20],
+	unsigned char *data, size_t datalen)
+{
+    unsigned char ipad[64], opad[64];
+    size_t i;
+    gcry_md_hd_t sha1;
+    gcry_error_t err;
+    unsigned char hash[20];
+
+    memset(ipad, 0, 64);
+    memset(opad, 0, 64);
+    memmove(ipad, key, 20);
+    memmove(opad, key, 20);
+    for(i=0;i<64;++i) {
+	ipad[i] ^= 0x36;
+	opad[i] ^= 0x5c;
+    }
+
+    err = gcry_md_open(&sha1, GCRY_MD_SHA1, 0);
+    if (err) {
+	fprintf(stderr, "Error: %s\n", gcry_strerror(err));
+	exit(1);
+    }
+    gcry_md_write(sha1, ipad, 64);
+    gcry_md_write(sha1, data, datalen);
+    memmove(hash, gcry_md_read(sha1, 0), 20);
+    gcry_md_reset(sha1);
+    gcry_md_write(sha1, opad, 64);
+    gcry_md_write(sha1, hash, 20);
+    memmove(digest, gcry_md_read(sha1, 0), 20);
+    gcry_md_close(sha1);
+}