diff src/mac/pmac/pmac_process.c @ 191:1c15b283127b libtomcrypt-orig

Import of libtomcrypt 1.02 with manual path rename rearrangement etc
author Matt Johnston <matt@ucc.asn.au>
date Fri, 06 May 2005 13:23:02 +0000
parents
children 39d5d58461d6
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/mac/pmac/pmac_process.c	Fri May 06 13:23:02 2005 +0000
@@ -0,0 +1,92 @@
+/* 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 pmac_process.c
+   PMAC implementation, process data, by Tom St Denis 
+*/
+
+
+#ifdef PMAC
+
+/**
+  Process data in a PMAC stream
+  @param pmac     The PMAC state
+  @param in       The data to send through PMAC
+  @param inlen    The length of the data to send through PMAC
+  @return CRYPT_OK if successful
+*/
+int pmac_process(pmac_state *pmac, const unsigned char *in, unsigned long inlen)
+{
+   int err, n;
+   unsigned long x;
+   unsigned char Z[MAXBLOCKSIZE];
+
+   LTC_ARGCHK(pmac != NULL);
+   LTC_ARGCHK(in   != NULL);
+   if ((err = cipher_is_valid(pmac->cipher_idx)) != CRYPT_OK) {
+      return err;
+   }
+
+   if ((pmac->buflen > (int)sizeof(pmac->block)) || (pmac->buflen < 0) ||
+       (pmac->block_len > (int)sizeof(pmac->block)) || (pmac->buflen > pmac->block_len)) {
+      return CRYPT_INVALID_ARG;
+   }
+
+#ifdef LTC_FAST
+   if (pmac->buflen == 0 && inlen > 16) {
+      unsigned long y;
+      for (x = 0; x < (inlen - 16); x += 16) {
+          pmac_shift_xor(pmac);
+          for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
+              *((LTC_FAST_TYPE*)(&Z[y])) = *((LTC_FAST_TYPE*)(&in[y])) ^ *((LTC_FAST_TYPE*)(&pmac->Li[y]));
+          }
+          cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key);
+          for (y = 0; y < 16; y += sizeof(LTC_FAST_TYPE)) {
+              *((LTC_FAST_TYPE*)(&pmac->checksum[y])) ^= *((LTC_FAST_TYPE*)(&Z[y]));
+          }
+          in += 16;
+      }
+      inlen -= x;
+   }
+#endif
+
+   while (inlen != 0) { 
+       /* ok if the block is full we xor in prev, encrypt and replace prev */
+       if (pmac->buflen == pmac->block_len) {
+          pmac_shift_xor(pmac);
+          for (x = 0; x < (unsigned long)pmac->block_len; x++) {
+               Z[x] = pmac->Li[x] ^ pmac->block[x];
+          }
+          cipher_descriptor[pmac->cipher_idx].ecb_encrypt(Z, Z, &pmac->key);
+          for (x = 0; x < (unsigned long)pmac->block_len; x++) {
+              pmac->checksum[x] ^= Z[x];
+          }
+          pmac->buflen = 0;
+       }
+
+       /* add bytes */
+       n = MIN(inlen, (unsigned long)(pmac->block_len - pmac->buflen));
+       XMEMCPY(pmac->block + pmac->buflen, in, n);
+       pmac->buflen  += n;
+       inlen         -= n;
+       in            += n;
+   }
+
+#ifdef LTC_CLEAN_STACK
+   zeromem(Z, sizeof(Z));
+#endif
+
+   return CRYPT_OK;
+}
+
+#endif