--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/modes/cbc/cbc_encrypt.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 cbc_encrypt.c
+   CBC implementation, encrypt block, Tom St Denis
+*/
+
+
+#ifdef CBC
+
+/**
+  CBC encrypt
+  @param pt     Plaintext
+  @param ct     [out] Ciphertext
+  @param len    The number of bytes to process (must be multiple of block length)
+  @param cbc    CBC state
+  @return CRYPT_OK if successful
+*/
+int cbc_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_CBC *cbc)
+{
+   int x, err;
+
+   LTC_ARGCHK(pt != NULL);
+   LTC_ARGCHK(ct != NULL);
+   LTC_ARGCHK(cbc != NULL);
+
+   if ((err = cipher_is_valid(cbc->cipher)) != CRYPT_OK) {
+       return err;
+   }
+   
+   /* is blocklen valid? */
+   if (cbc->blocklen < 0 || cbc->blocklen > (int)sizeof(cbc->IV)) {
+      return CRYPT_INVALID_ARG;
+   }    
+
+   if (len % cbc->blocklen) {
+      return CRYPT_INVALID_ARG;
+   }
+#ifdef LTC_FAST
+   if (len % sizeof(LTC_FAST_TYPE)) {   
+      return CRYPT_INVALID_ARG;
+   }
+#endif
+
+   if (cipher_descriptor[cbc->cipher].accel_cbc_encrypt != NULL) {
+      cipher_descriptor[cbc->cipher].accel_cbc_encrypt(pt, ct, len / cbc->blocklen, cbc->IV, &cbc->key);
+   } else {
+      while (len) {
+         /* xor IV against plaintext */
+         #if defined(LTC_FAST)
+	     for (x = 0; x < cbc->blocklen; x += sizeof(LTC_FAST_TYPE)) {
+	         *((LTC_FAST_TYPE*)((unsigned char *)cbc->IV + x)) ^= *((LTC_FAST_TYPE*)((unsigned char *)pt + x));
+	     }
+	 #else 
+            for (x = 0; x < cbc->blocklen; x++) {
+               cbc->IV[x] ^= pt[x];
+            }
+	 #endif
+
+         /* encrypt */
+         cipher_descriptor[cbc->cipher].ecb_encrypt(cbc->IV, ct, &cbc->key);
+
+        /* store IV [ciphertext] for a future block */
+         #if defined(LTC_FAST)
+	     for (x = 0; x < cbc->blocklen; x += sizeof(LTC_FAST_TYPE)) {
+	         *((LTC_FAST_TYPE*)((unsigned char *)cbc->IV + x)) = *((LTC_FAST_TYPE*)((unsigned char *)ct + x));
+	     }
+	 #else 
+             for (x = 0; x < cbc->blocklen; x++) {
+                cbc->IV[x] = ct[x];
+             }
+	 #endif
+        
+        ct  += cbc->blocklen;
+        pt  += cbc->blocklen;
+        len -= cbc->blocklen;
+     }
+   }
+   return CRYPT_OK;
+}
+
+#endif