--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/yarrow.c	Mon May 31 18:25:41 2004 +0000
@@ -0,0 +1,167 @@
+/* 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 "mycrypt.h"
+
+#ifdef YARROW
+
+const struct _prng_descriptor yarrow_desc =
+{
+    "yarrow",
+    &yarrow_start,
+    &yarrow_add_entropy,
+    &yarrow_ready,
+    &yarrow_read
+};
+
+int yarrow_start(prng_state *prng)
+{
+   int err;
+   
+   _ARGCHK(prng != NULL);
+
+   /* these are the default hash/cipher combo used */
+#ifdef RIJNDAEL
+   prng->yarrow.cipher = register_cipher(&rijndael_desc);
+#elif defined(BLOWFISH)
+   prng->yarrow.cipher = register_cipher(&blowfish_desc);
+#elif defined(TWOFISH)
+   prng->yarrow.cipher = register_cipher(&twofish_desc);
+#elif defined(RC6)
+   prng->yarrow.cipher = register_cipher(&rc6_desc);
+#elif defined(RC5)
+   prng->yarrow.cipher = register_cipher(&rc5_desc);
+#elif defined(SAFERP)
+   prng->yarrow.cipher = register_cipher(&saferp_desc);
+#elif defined(RC2)
+   prng->yarrow.cipher = register_cipher(&rc2_desc);
+#elif defined(NOEKEON)   
+   prng->yarrow.cipher = register_cipher(&noekeon_desc);
+#elif defined(CAST5)
+   prng->yarrow.cipher = register_cipher(&cast5_desc);
+#elif defined(XTEA)
+   prng->yarrow.cipher = register_cipher(&xtea_desc);
+#elif defined(SAFER)
+   prng->yarrow.cipher = register_cipher(&safer_sk128_desc);
+#elif defined(DES)
+   prng->yarrow.cipher = register_cipher(&des3_desc);
+#elif
+   #error YARROW needs at least one CIPHER
+#endif
+   if ((err = cipher_is_valid(prng->yarrow.cipher)) != CRYPT_OK) {
+      return err;
+   }
+
+#ifdef SHA256
+   prng->yarrow.hash   = register_hash(&sha256_desc);
+#elif defined(SHA512)
+   prng->yarrow.hash   = register_hash(&sha512_desc);
+#elif defined(TIGER)
+   prng->yarrow.hash   = register_hash(&tiger_desc);
+#elif defined(SHA1)
+   prng->yarrow.hash   = register_hash(&sha1_desc);
+#elif defined(RIPEMD160)
+   prng->yarrow.hash   = register_hash(&rmd160_desc);
+#elif defined(RIPEMD128)
+   prng->yarrow.hash   = register_hash(&rmd128_desc);
+#elif defined(MD5)
+   prng->yarrow.hash   = register_hash(&md5_desc);
+#elif defined(MD4)
+   prng->yarrow.hash   = register_hash(&md4_desc);
+#elif defined(MD2)
+   prng->yarrow.hash   = register_hash(&md2_desc);
+#else
+   #error YARROW needs at least one HASH
+#endif
+   if ((err = hash_is_valid(prng->yarrow.hash)) != CRYPT_OK) {
+      return err;
+   }
+
+   /* zero the memory used */
+   zeromem(prng->yarrow.pool, sizeof(prng->yarrow.pool));
+
+   return CRYPT_OK;
+}
+
+int yarrow_add_entropy(const unsigned char *buf, unsigned long len, prng_state *prng)
+{
+   hash_state md;
+   int err;
+
+   _ARGCHK(buf  != NULL);
+   _ARGCHK(prng != NULL);
+
+   if ((err = hash_is_valid(prng->yarrow.hash)) != CRYPT_OK) {
+      return err;
+   }
+
+   /* start the hash */
+   hash_descriptor[prng->yarrow.hash].init(&md);
+
+   /* hash the current pool */
+   hash_descriptor[prng->yarrow.hash].process(&md, prng->yarrow.pool, hash_descriptor[prng->yarrow.hash].hashsize);
+
+   /* add the new entropy */
+   hash_descriptor[prng->yarrow.hash].process(&md, buf, len);
+
+   /* store result */
+   hash_descriptor[prng->yarrow.hash].done(&md, prng->yarrow.pool);
+
+   return CRYPT_OK;
+}
+
+int yarrow_ready(prng_state *prng)
+{
+   int ks, err;
+
+   _ARGCHK(prng != NULL);
+
+   if ((err = hash_is_valid(prng->yarrow.hash)) != CRYPT_OK) {
+      return err;
+   }
+   
+   if ((err = cipher_is_valid(prng->yarrow.cipher)) != CRYPT_OK) {
+      return err;
+   }
+
+   /* setup CTR mode using the "pool" as the key */
+   ks = (int)hash_descriptor[prng->yarrow.hash].hashsize;
+   if ((err = cipher_descriptor[prng->yarrow.cipher].keysize(&ks)) != CRYPT_OK) {
+      return err;
+   }
+
+   if ((err = ctr_start(prng->yarrow.cipher,     /* what cipher to use */
+                        prng->yarrow.pool,       /* IV */
+                        prng->yarrow.pool, ks,   /* KEY and key size */
+                        0,                       /* number of rounds */
+                        &prng->yarrow.ctr)) != CRYPT_OK) {
+      return err;
+   }
+   return CRYPT_OK;
+}
+
+unsigned long yarrow_read(unsigned char *buf, unsigned long len, prng_state *prng)
+{
+   _ARGCHK(buf  != NULL);
+   _ARGCHK(prng != NULL);
+
+   /* put buf in predictable state first */
+   zeromem(buf, len);
+   
+   /* now randomize it */
+   if (ctr_encrypt(buf, buf, len, &prng->yarrow.ctr) != CRYPT_OK) {
+      return 0;
+   }
+   return len;
+}
+
+#endif
+