libtomcrypt/yarrow.c
2010-06-16 12:37:56 +02:00

151 lines
3.8 KiB
C

#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(NOEKEON)
prng->yarrow.cipher = register_cipher(&noekeon_desc);
#elif defined(BLOWFISH)
prng->yarrow.cipher = register_cipher(&blowfish_desc);
#elif defined(TWOFISH)
prng->yarrow.cipher = register_cipher(&twofish_desc);
#elif defined(CAST5)
prng->yarrow.cipher = register_cipher(&cast5_desc);
#elif defined(SERPENT)
prng->yarrow.cipher = register_cipher(&serpent_desc);
#elif defined(SAFER)
prng->yarrow.cipher = register_cipher(&saferp_desc);
#elif defined(RC5)
prng->yarrow.cipher = register_cipher(&rc5_desc);
#elif defined(RC6)
prng->yarrow.cipher = register_cipher(&rc6_desc);
#elif defined(XTEA)
prng->yarrow.cipher = register_cipher(&xtea_desc);
#elif defined(RC2)
prng->yarrow.cipher = register_cipher(&rc2_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(SHA384)
prng->yarrow.hash = register_hash(&sha384_desc);
#elif defined(SHA1)
prng->yarrow.hash = register_hash(&sha1_desc);
#elif defined(TIGER)
prng->yarrow.hash = register_hash(&tiger_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, prng->yarrow.pool, prng->yarrow.pool, ks, 0, &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