diff src/encauth/ocb/ocb_encrypt_authenticate_memory.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/encauth/ocb/ocb_encrypt_authenticate_memory.c	Fri May 06 13:23:02 2005 +0000
@@ -0,0 +1,80 @@
+/* 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
+ */
+
+/** 
+  @file ocb_encrypt_authenticate_memory.c
+  OCB implementation, encrypt block of memory, by Tom St Denis
+*/
+#include "tomcrypt.h"
+
+#ifdef OCB_MODE
+
+/**
+   Encrypt and generate an authentication code for a buffer of memory
+   @param cipher     The index of the cipher desired
+   @param key        The secret key
+   @param keylen     The length of the secret key (octets)
+   @param nonce      The session nonce (length of the block ciphers block size)
+   @param pt         The plaintext
+   @param ptlen      The length of the plaintext (octets)
+   @param ct         [out] The ciphertext
+   @param tag        [out] The authentication tag
+   @param taglen     [in/out] The max size and resulting size of the authentication tag
+   @return CRYPT_OK if successful
+*/
+int ocb_encrypt_authenticate_memory(int cipher,
+    const unsigned char *key,    unsigned long keylen,
+    const unsigned char *nonce,  
+    const unsigned char *pt,     unsigned long ptlen,
+          unsigned char *ct,
+          unsigned char *tag,    unsigned long *taglen)
+{
+   int err;
+   ocb_state *ocb;
+
+   LTC_ARGCHK(key    != NULL);
+   LTC_ARGCHK(nonce  != NULL);
+   LTC_ARGCHK(pt     != NULL);
+   LTC_ARGCHK(ct     != NULL);
+   LTC_ARGCHK(tag    != NULL);
+   LTC_ARGCHK(taglen != NULL);
+
+   /* allocate ram */
+   ocb = XMALLOC(sizeof(ocb_state));
+   if (ocb == NULL) {
+      return CRYPT_MEM;
+   }
+
+   if ((err = ocb_init(ocb, cipher, key, keylen, nonce)) != CRYPT_OK) {
+      goto LBL_ERR;
+   }
+
+   while (ptlen > (unsigned long)ocb->block_len) {
+        if ((err = ocb_encrypt(ocb, pt, ct)) != CRYPT_OK) {
+           goto LBL_ERR;
+        }
+        ptlen   -= ocb->block_len;
+        pt      += ocb->block_len;
+        ct      += ocb->block_len;
+   }
+
+   err = ocb_done_encrypt(ocb, pt, ptlen, ct, tag, taglen);
+LBL_ERR:
+#ifdef LTC_CLEAN_STACK
+   zeromem(ocb, sizeof(ocb_state));
+#endif
+
+   XFREE(ocb);
+
+   return err;
+}
+
+#endif