diff src/mac/omac/omac_process.c @ 192:9cc34777b479 libtomcrypt

propagate from branch 'au.asn.ucc.matt.ltc-orig' (head 9ba8f01f44320e9cb9f19881105ae84f84a43ea9) to branch 'au.asn.ucc.matt.dropbear.ltc' (head dbf51c569bc34956ad948e4cc87a0eeb2170b768)
author Matt Johnston <matt@ucc.asn.au>
date Sun, 08 May 2005 06:36:47 +0000
parents 1c15b283127b
children 39d5d58461d6
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/mac/omac/omac_process.c	Sun May 08 06:36:47 2005 +0000
@@ -0,0 +1,79 @@
+/* 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, [email protected], http://libtomcrypt.org
+ */
+#include "tomcrypt.h"
+
+/** 
+  @file omac_process.c
+  OMAC1 support, process data, Tom St Denis
+*/
+
+
+#ifdef 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)
+{
+   int err, n, x;
+
+   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;
+          cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->prev, omac->prev, &omac->key);
+      }
+      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 < omac->blklen; x++) {
+              omac->block[x] ^= omac->prev[x];
+          }
+          cipher_descriptor[omac->cipher_idx].ecb_encrypt(omac->block, omac->prev, &omac->key);
+          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
+