tomcrypt/yarrow.c
2010-06-16 12:38:22 +02:00

258 lines
6.3 KiB
C

/* 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@iahu.ca, http://libtomcrypt.org
*/
#include "mycrypt.h"
#ifdef YARROW
const struct _prng_descriptor yarrow_desc =
{
"yarrow", 64,
&yarrow_start,
&yarrow_add_entropy,
&yarrow_ready,
&yarrow_read,
&yarrow_done,
&yarrow_export,
&yarrow_import,
&yarrow_test
};
int yarrow_start(prng_state *prng)
{
int err;
_ARGCHK(prng != NULL);
/* these are the default hash/cipher combo used */
#ifdef RIJNDAEL
#if YARROW_AES==0
prng->yarrow.cipher = register_cipher(&rijndael_enc_desc);
#elif YARROW_AES==1
prng->yarrow.cipher = register_cipher(&aes_enc_desc);
#elif YARROW_AES==2
prng->yarrow.cipher = register_cipher(&rijndael_desc);
#elif YARROW_AES==3
prng->yarrow.cipher = register_cipher(&aes_desc);
#endif
#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);
#elif defined(WHIRLPOOL)
prng->yarrow.hash = register_hash(&whirlpool_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 */
if ((err = hash_descriptor[prng->yarrow.hash].process(&md, prng->yarrow.pool,
hash_descriptor[prng->yarrow.hash].hashsize)) != CRYPT_OK) {
return err;
}
/* add the new entropy */
if ((err = hash_descriptor[prng->yarrow.hash].process(&md, buf, len)) != CRYPT_OK) {
return err;
}
/* store result */
if ((err = hash_descriptor[prng->yarrow.hash].done(&md, prng->yarrow.pool)) != CRYPT_OK) {
return err;
}
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;
}
int yarrow_done(prng_state *prng)
{
_ARGCHK(prng != NULL);
/* call cipher done when we invent one ;-) */
return CRYPT_OK;
}
int yarrow_export(unsigned char *out, unsigned long *outlen, prng_state *prng)
{
_ARGCHK(out != NULL);
_ARGCHK(outlen != NULL);
_ARGCHK(prng != NULL);
/* we'll write 64 bytes for s&g's */
if (*outlen < 64) {
return CRYPT_BUFFER_OVERFLOW;
}
if (yarrow_read(out, 64, prng) != 64) {
return CRYPT_ERROR_READPRNG;
}
*outlen = 64;
return CRYPT_OK;
}
int yarrow_import(const unsigned char *in, unsigned long inlen, prng_state *prng)
{
int err;
_ARGCHK(in != NULL);
_ARGCHK(prng != NULL);
if (inlen != 64) {
return CRYPT_INVALID_ARG;
}
if ((err = yarrow_start(prng)) != CRYPT_OK) {
return err;
}
return yarrow_add_entropy(in, 64, prng);
}
int yarrow_test(void)
{
#ifndef LTC_TEST
return CRYPT_NOP;
#else
int err;
prng_state prng;
if ((err = yarrow_start(&prng)) != CRYPT_OK) {
return err;
}
/* now let's test the hash/cipher that was chosen */
if ((err = cipher_descriptor[prng.yarrow.cipher].test()) != CRYPT_OK) {
return err;
}
if ((err = hash_descriptor[prng.yarrow.hash].test()) != CRYPT_OK) {
return err;
}
yarrow_done(&prng);
return CRYPT_OK;
#endif
}
#endif