diff pmac_done.c @ 3:7faae8f46238 libtomcrypt-orig

Branch renaming
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:25:41 +0000
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pmac_done.c	Mon May 31 18:25:41 2004 +0000
@@ -0,0 +1,64 @@
+/* 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
+ */
+
+/* PMAC implementation by Tom St Denis */
+#include "mycrypt.h"
+
+#ifdef PMAC
+
+int pmac_done(pmac_state *state, unsigned char *out, unsigned long *outlen)
+{
+   int err, x;
+
+   _ARGCHK(state != NULL);
+   _ARGCHK(out   != NULL);
+   if ((err = cipher_is_valid(state->cipher_idx)) != CRYPT_OK) {
+      return err;
+   }
+
+   if ((state->buflen > (int)sizeof(state->block)) || (state->buflen < 0) ||
+       (state->block_len > (int)sizeof(state->block)) || (state->buflen > state->block_len)) {
+      return CRYPT_INVALID_ARG;
+   }
+
+
+   /* handle padding.  If multiple xor in L/x */
+
+   if (state->buflen == state->block_len) {
+      /* xor Lr against the checksum */
+      for (x = 0; x < state->block_len; x++) {
+          state->checksum[x] ^= state->block[x] ^ state->Lr[x];
+      }
+   } else {
+      /* otherwise xor message bytes then the 0x80 byte */
+      for (x = 0; x < state->buflen; x++) {
+          state->checksum[x] ^= state->block[x];
+      }
+      state->checksum[x] ^= 0x80;
+   }
+
+   /* encrypt it */
+   cipher_descriptor[state->cipher_idx].ecb_encrypt(state->checksum, state->checksum, &state->key);
+
+   /* store it */
+   for (x = 0; x < state->block_len && x <= (int)*outlen; x++) {
+       out[x] = state->checksum[x];
+   }
+   *outlen = x;
+
+#ifdef CLEAN_STACK
+   zeromem(state, sizeof(*state));
+#endif
+   return CRYPT_OK;
+}
+
+#endif
+