1 files changed, 103 insertions, 0 deletions
diff --git a/src/modes/f8/f8_encrypt.c b/src/modes/f8/f8_encrypt.c
new file mode 100644
index 0000000..fc33be9
--- /dev/null
+++ b/src/modes/f8/f8_encrypt.c
@@ -0,0 +1,103 @@
+/* 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, tomstdenis@gmail.com, http://libtomcrypt.com
+ */
+#include "tomcrypt.h"
+
+/**
+  @file f8_encrypt.c
+  F8 implementation, encrypt data, Tom St Denis
+*/
+
+#ifdef LTC_F8_MODE
+
+/**
+  F8 encrypt
+  @param pt     Plaintext
+  @param ct     [out] Ciphertext
+  @param len    Length of plaintext (octets)
+  @param f8     F8 state
+  @return CRYPT_OK if successful
+*/
+int f8_encrypt(const unsigned char *pt, unsigned char *ct, unsigned long len, symmetric_F8 *f8)
+{
+   int           err, x;
+   unsigned char buf[MAXBLOCKSIZE];
+   LTC_ARGCHK(pt != NULL);
+   LTC_ARGCHK(ct != NULL);
+   LTC_ARGCHK(f8 != NULL);
+   if ((err = cipher_is_valid(f8->cipher)) != CRYPT_OK) {
+       return err;
+   }
+   
+   /* is blocklen/padlen valid? */
+   if (f8->blocklen < 0 || f8->blocklen > (int)sizeof(f8->IV) ||
+       f8->padlen   < 0 || f8->padlen   > (int)sizeof(f8->IV)) {
+      return CRYPT_INVALID_ARG;
+   }
+   
+   zeromem(buf, sizeof(buf));
+
+   /* make sure the pad is empty */
+   if (f8->padlen == f8->blocklen) {
+      /* xor of IV, MIV and blockcnt == what goes into cipher */
+      STORE32H(f8->blockcnt, (buf+(f8->blocklen-4)));
+      ++(f8->blockcnt);
+      for (x = 0; x < f8->blocklen; x++) {
+          f8->IV[x] ^= f8->MIV[x] ^ buf[x];
+      }
+      if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(f8->IV, f8->IV, &f8->key)) != CRYPT_OK) {
+         return err;
+      }
+      f8->padlen = 0;
+   }
+
+#ifdef LTC_FAST
+   if (f8->padlen == 0) {
+      while (len >= (unsigned long)f8->blocklen) {
+         STORE32H(f8->blockcnt, (buf+(f8->blocklen-4)));
+         ++(f8->blockcnt);
+         for (x = 0; x < f8->blocklen; x += sizeof(LTC_FAST_TYPE)) {
+             *((LTC_FAST_TYPE*)(&ct[x])) = *((LTC_FAST_TYPE*)(&pt[x])) ^ *((LTC_FAST_TYPE*)(&f8->IV[x]));
+             *((LTC_FAST_TYPE*)(&f8->IV[x])) ^= *((LTC_FAST_TYPE*)(&f8->MIV[x])) ^ *((LTC_FAST_TYPE*)(&buf[x]));
+         }
+         if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(f8->IV, f8->IV, &f8->key)) != CRYPT_OK) {
+            return err;
+         }
+         len -= x;
+         pt  += x;
+         ct  += x;
+      }
+   }
+#endif             
+
+   while (len > 0) {
+       if (f8->padlen == f8->blocklen) {
+          /* xor of IV, MIV and blockcnt == what goes into cipher */
+          STORE32H(f8->blockcnt, (buf+(f8->blocklen-4)));
+          ++(f8->blockcnt);
+          for (x = 0; x < f8->blocklen; x++) {
+              f8->IV[x] ^= f8->MIV[x] ^ buf[x];
+          }
+          if ((err = cipher_descriptor[f8->cipher].ecb_encrypt(f8->IV, f8->IV, &f8->key)) != CRYPT_OK) {
+             return err;
+          }
+          f8->padlen = 0;
+       }
+       *ct++ = *pt++ ^ f8->IV[f8->padlen++];
+       --len;
+   }
+   return CRYPT_OK;
+}
+
+#endif
+
+/* $Source: /cvs/libtom/libtomcrypt/src/modes/f8/f8_encrypt.c,v $ */
+/* $Revision: 1.6 $ */
+/* $Date: 2006/11/05 04:16:32 $ */