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authorMatt Johnston <matt@ucc.asn.au>2006-03-08 12:58:00 +0000
committerMatt Johnston <matt@ucc.asn.au>2006-03-08 12:58:00 +0000
commitc57e1d8def6e38d350da8b098a91806d405e952e (patch)
treedbd7bff4e514b7bfd2f2fe365eeaaea77ebafffd /src/mac/hmac/hmac_done.c
Re-import libtomcrypt 1.05 for cleaner propagating.
From crypt-1.05.tar.bz2, SHA1 of 88250202bb51570dc64f7e8f1c943cda9479258f --HG-- branch : libtomcrypt-orig extra : convert_revision : 5c0c50e93111636ccf8deb758a689ad713797baf
Diffstat (limited to 'src/mac/hmac/hmac_done.c')
-rw-r--r--src/mac/hmac/hmac_done.c109
1 files changed, 109 insertions, 0 deletions
diff --git a/src/mac/hmac/hmac_done.c b/src/mac/hmac/hmac_done.c
new file mode 100644
index 0000000..f64d044
--- /dev/null
+++ b/src/mac/hmac/hmac_done.c
@@ -0,0 +1,109 @@
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/**
+ @file hmac_done.c
+ HMAC support, terminate stream, Tom St Denis/Dobes Vandermeer
+*/
+
+#ifdef HMAC
+
+#define HMAC_BLOCKSIZE hash_descriptor[hash].blocksize
+
+/**
+ Terminate an HMAC session
+ @param hmac The HMAC state
+ @param out [out] The destination of the HMAC authentication tag
+ @param outlen [in/out] The max size and resulting size of the HMAC authentication tag
+ @return CRYPT_OK if successful
+*/
+int hmac_done(hmac_state *hmac, unsigned char *out, unsigned long *outlen)
+{
+ unsigned char *buf, *isha;
+ unsigned long hashsize, i;
+ int hash, err;
+
+ LTC_ARGCHK(hmac != NULL);
+ LTC_ARGCHK(out != NULL);
+
+ /* test hash */
+ hash = hmac->hash;
+ if((err = hash_is_valid(hash)) != CRYPT_OK) {
+ return err;
+ }
+
+ /* get the hash message digest size */
+ hashsize = hash_descriptor[hash].hashsize;
+
+ /* allocate buffers */
+ buf = XMALLOC(HMAC_BLOCKSIZE);
+ isha = XMALLOC(hashsize);
+ if (buf == NULL || isha == NULL) {
+ if (buf != NULL) {
+ XFREE(buf);
+ }
+ if (isha != NULL) {
+ XFREE(isha);
+ }
+ return CRYPT_MEM;
+ }
+
+ /* Get the hash of the first HMAC vector plus the data */
+ if ((err = hash_descriptor[hash].done(&hmac->md, isha)) != CRYPT_OK) {
+ goto LBL_ERR;
+ }
+
+ /* Create the second HMAC vector vector for step (3) */
+ for(i=0; i < HMAC_BLOCKSIZE; i++) {
+ buf[i] = hmac->key[i] ^ 0x5C;
+ }
+
+ /* Now calculate the "outer" hash for step (5), (6), and (7) */
+ if ((err = hash_descriptor[hash].init(&hmac->md)) != CRYPT_OK) {
+ goto LBL_ERR;
+ }
+ if ((err = hash_descriptor[hash].process(&hmac->md, buf, HMAC_BLOCKSIZE)) != CRYPT_OK) {
+ goto LBL_ERR;
+ }
+ if ((err = hash_descriptor[hash].process(&hmac->md, isha, hashsize)) != CRYPT_OK) {
+ goto LBL_ERR;
+ }
+ if ((err = hash_descriptor[hash].done(&hmac->md, buf)) != CRYPT_OK) {
+ goto LBL_ERR;
+ }
+
+ /* copy to output */
+ for (i = 0; i < hashsize && i < *outlen; i++) {
+ out[i] = buf[i];
+ }
+ *outlen = i;
+
+ err = CRYPT_OK;
+LBL_ERR:
+ XFREE(hmac->key);
+#ifdef LTC_CLEAN_STACK
+ zeromem(isha, hashsize);
+ zeromem(buf, hashsize);
+ zeromem(hmac, sizeof(*hmac));
+#endif
+
+ XFREE(isha);
+ XFREE(buf);
+
+ return err;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/mac/hmac/hmac_done.c,v $ */
+/* $Revision: 1.3 $ */
+/* $Date: 2005/05/05 14:35:58 $ */