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

Branch renaming
author Matt Johnston <matt@ucc.asn.au>
date Mon, 31 May 2004 18:25:41 +0000
parents
children 5d99163f7e32
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/eax_decrypt_verify_memory.c	Mon May 31 18:25:41 2004 +0000
@@ -0,0 +1,60 @@
+/* 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
+ */
+
+/* EAX Implementation by Tom St Denis */
+#include "mycrypt.h"
+
+#ifdef EAX_MODE
+
+int eax_decrypt_verify_memory(int cipher,
+    const unsigned char *key,    unsigned long keylen,
+    const unsigned char *nonce,  unsigned long noncelen,
+    const unsigned char *header, unsigned long headerlen,
+    const unsigned char *ct,     unsigned long ctlen,
+          unsigned char *pt,
+          unsigned char *tag,    unsigned long taglen,
+          int           *res)
+{
+   int err;
+   eax_state eax;
+   unsigned char buf[MAXBLOCKSIZE];
+   unsigned long buflen;
+
+   _ARGCHK(res != NULL);
+
+   /* default to zero */
+   *res = 0;
+
+   if ((err = eax_init(&eax, cipher, key, keylen, nonce, noncelen, header, headerlen)) != CRYPT_OK) {
+      return err;
+   }
+
+   if ((err = eax_decrypt(&eax, ct, pt, ctlen)) != CRYPT_OK) {
+      return err;
+   }
+ 
+   buflen = MIN(sizeof(buf), taglen);
+   if ((err = eax_done(&eax, buf, &buflen)) != CRYPT_OK) {
+      return err;
+   }
+
+   /* compare tags */
+   if (buflen >= taglen && memcmp(buf, tag, taglen) == 0) {
+      *res = 1;
+   }
+
+#ifdef CLEAN_STACK
+   zeromem(buf, sizeof(buf));
+#endif
+   return CRYPT_OK;
+}
+
+#endif