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-rw-r--r--libtomcrypt/src/mac/omac/omac_process.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/libtomcrypt/src/mac/omac/omac_process.c b/libtomcrypt/src/mac/omac/omac_process.c
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+++ b/libtomcrypt/src/mac/omac/omac_process.c
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+/* 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.com
+ */
+#include "tomcrypt.h"
+
+/**
+ @file omac_process.c
+ OMAC1 support, process data, Tom St Denis
+*/
+
+
+#ifdef LTC_OMAC
+
+/**
+ Process data through OMAC
+ @param omac The OMAC state
+ @param in The input data to send through OMAC
+ @param inlen The length of the input (octets)
+ @return CRYPT_OK if successful
+*/
+int omac_process(omac_state *omac, const unsigned char *in, unsigned long inlen)
+{
+ unsigned long n, x;
+ int err;
+
+ LTC_ARGCHK(omac != NULL);
+ LTC_ARGCHK(in != NULL);
+ if ((err = cipher_is_valid(omac->cipher_idx)) != CRYPT_OK) {
+ return err;
+ }
+
+ if ((omac->buflen > (int)sizeof(omac->block)) || (omac->buflen < 0) ||
+ (omac->blklen > (int)sizeof(omac->block)) || (omac->buflen > omac->blklen)) {
+ return CRYPT_INVALID_ARG;
+ }
+
+#ifdef LTC_FAST
+ if (omac->buflen == 0 && inlen > 16) {
+ int y;
+ for (x = 0; x < (inlen - 16); x += 16) {
+ for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
+ *((LTC_FAST_TYPE*)(&omac->prev[y])) ^= *((LTC_FAST_TYPE*)(&in[y]));
+ }
+ in += 16;
+ if ((err = cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->prev, omac->prev, &omac->key)) != CRYPT_OK) {
+ return err;
+ }
+ }
+ inlen -= x;
+ }
+#endif
+
+ while (inlen != 0) {
+ /* ok if the block is full we xor in prev, encrypt and replace prev */
+ if (omac->buflen == omac->blklen) {
+ for (x = 0; x < (unsigned long)omac->blklen; x++) {
+ omac->block[x] ^= omac->prev[x];
+ }
+ if ((err = cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->prev, &omac->key)) != CRYPT_OK) {
+ return err;
+ }
+ omac->buflen = 0;
+ }
+
+ /* add bytes */
+ n = MIN(inlen, (unsigned long)(omac->blklen - omac->buflen));
+ XMEMCPY(omac->block + omac->buflen, in, n);
+ omac->buflen += n;
+ inlen -= n;
+ in += n;
+ }
+
+ return CRYPT_OK;
+}
+
+#endif
+
+
+/* $Source: /cvs/libtom/libtomcrypt/src/mac/omac/omac_process.c,v $ */
+/* $Revision: 1.9 $ */
+/* $Date: 2006/11/03 00:39:49 $ */