X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=libtomcrypt%2Fsrc%2Fmac%2Fxcbc%2Fxcbc_init.c;fp=libtomcrypt%2Fsrc%2Fmac%2Fxcbc%2Fxcbc_init.c;h=4eccd5e4ed0557ef76509833e4b3c3aec71794a9;hb=66bc25938679f1d6a1d1200f329093d82a5e99b4;hp=0000000000000000000000000000000000000000;hpb=a52ee0733f420ca20224049260d6fc5cf7d8f621;p=zpackage

diff --git a/libtomcrypt/src/mac/xcbc/xcbc_init.c b/libtomcrypt/src/mac/xcbc/xcbc_init.c
new file mode 100644
index 0000000..4eccd5e
--- /dev/null
+++ b/libtomcrypt/src/mac/xcbc/xcbc_init.c
@@ -0,0 +1,106 @@
+/* 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.
+ */
+#include "tomcrypt.h"
+
+/**
+  @file xcbc_init.c
+  XCBC Support, start an XCBC state
+*/
+
+#ifdef LTC_XCBC
+
+/** Initialize XCBC-MAC state
+  @param xcbc    [out] XCBC state to initialize
+  @param cipher  Index of cipher to use
+  @param key     [in]  Secret key
+  @param keylen  Length of secret key in octets
+  Return CRYPT_OK on success
+*/
+int xcbc_init(xcbc_state *xcbc, int cipher, const unsigned char *key, unsigned long keylen)
+{
+   int            x, y, err;
+   symmetric_key *skey;
+   unsigned long  k1;
+
+   LTC_ARGCHK(xcbc != NULL);
+   LTC_ARGCHK(key  != NULL);
+
+   /* schedule the key */
+   if ((err = cipher_is_valid(cipher)) != CRYPT_OK) {
+      return err;
+   }
+
+#ifdef LTC_FAST
+   if (cipher_descriptor[cipher].block_length % sizeof(LTC_FAST_TYPE)) {
+       return CRYPT_INVALID_ARG;
+   }
+#endif
+
+   skey = NULL;
+
+   /* are we in pure XCBC mode with three keys? */
+   if (keylen & LTC_XCBC_PURE) {
+      keylen &= ~LTC_XCBC_PURE;
+
+      if (keylen < 2UL*cipher_descriptor[cipher].block_length) {
+         return CRYPT_INVALID_ARG;
+      }
+
+      k1      = keylen - 2*cipher_descriptor[cipher].block_length;
+      XMEMCPY(xcbc->K[0], key, k1);
+      XMEMCPY(xcbc->K[1], key+k1, cipher_descriptor[cipher].block_length);
+      XMEMCPY(xcbc->K[2], key+k1 + cipher_descriptor[cipher].block_length, cipher_descriptor[cipher].block_length);
+   } else {
+      /* use the key expansion */
+      k1      = cipher_descriptor[cipher].block_length;
+
+      /* schedule the user key */
+      skey = XCALLOC(1, sizeof(*skey));
+      if (skey == NULL) {
+         return CRYPT_MEM;
+      }
+
+      if ((err = cipher_descriptor[cipher].setup(key, keylen, 0, skey)) != CRYPT_OK) {
+         goto done;
+      }
+
+      /* make the three keys */
+      for (y = 0; y < 3; y++) {
+        for (x = 0; x < cipher_descriptor[cipher].block_length; x++) {
+           xcbc->K[y][x] = y + 1;
+        }
+        cipher_descriptor[cipher].ecb_encrypt(xcbc->K[y], xcbc->K[y], skey);
+      }
+   }
+
+   /* setup K1 */
+   err = cipher_descriptor[cipher].setup(xcbc->K[0], k1, 0, &xcbc->key);
+
+   /* setup struct */
+   zeromem(xcbc->IV, cipher_descriptor[cipher].block_length);
+   xcbc->blocksize = cipher_descriptor[cipher].block_length;
+   xcbc->cipher    = cipher;
+   xcbc->buflen    = 0;
+done:
+   cipher_descriptor[cipher].done(skey);
+   if (skey != NULL) {
+#ifdef LTC_CLEAN_STACK
+      zeromem(skey, sizeof(*skey));
+#endif
+      XFREE(skey);
+   }
+   return err;
+}
+
+#endif
+
+/* ref:         $Format:%D$ */
+/* git commit:  $Format:%H$ */
+/* commit time: $Format:%ai$ */
+