mirror of
https://github.com/reactos/reactos.git
synced 2024-11-28 14:03:37 +08:00
249 lines
9.2 KiB
C
249 lines
9.2 KiB
C
/*
|
|
* dlls/rsaenh/rsa.c
|
|
* RSA public key cryptographic functions
|
|
*
|
|
* Copyright 2004 Michael Jung
|
|
* Based on public domain code by Tom St Denis (tomstdenis@iahu.ca)
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with this library; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
|
|
*/
|
|
|
|
/*
|
|
* This file contains code from the LibTomCrypt cryptographic
|
|
* library written by Tom St Denis (tomstdenis@iahu.ca). LibTomCrypt
|
|
* is in the public domain. The code in this file is tailored to
|
|
* special requirements. Take a look at http://libtomcrypt.org for the
|
|
* original version.
|
|
*/
|
|
|
|
#include "tomcrypt.h"
|
|
|
|
static const struct {
|
|
int mpi_code, ltc_code;
|
|
} mpi_to_ltc_codes[] = {
|
|
{ MP_OKAY , CRYPT_OK},
|
|
{ MP_MEM , CRYPT_MEM},
|
|
{ MP_VAL , CRYPT_INVALID_ARG},
|
|
};
|
|
|
|
/* convert a MPI error to a LTC error (Possibly the most powerful function ever! Oh wait... no) */
|
|
static int mpi_to_ltc_error(int err)
|
|
{
|
|
int x;
|
|
|
|
for (x = 0; x < (int)(sizeof(mpi_to_ltc_codes)/sizeof(mpi_to_ltc_codes[0])); x++) {
|
|
if (err == mpi_to_ltc_codes[x].mpi_code) {
|
|
return mpi_to_ltc_codes[x].ltc_code;
|
|
}
|
|
}
|
|
return CRYPT_ERROR;
|
|
}
|
|
|
|
extern int gen_rand_impl(unsigned char *dst, unsigned int len);
|
|
|
|
static int rand_prime_helper(unsigned char *dst, int len, void *dat)
|
|
{
|
|
return gen_rand_impl(dst, len) ? len : 0;
|
|
}
|
|
|
|
static int rand_prime(mp_int *N, long len)
|
|
{
|
|
int type;
|
|
|
|
/* get type */
|
|
if (len < 0) {
|
|
type = LTM_PRIME_BBS;
|
|
len = -len;
|
|
} else {
|
|
/* This seems to be what MS CSP's do: */
|
|
type = LTM_PRIME_2MSB_ON;
|
|
/* Original LibTomCrypt: type = 0; */
|
|
}
|
|
|
|
/* allow sizes between 2 and 256 bytes for a prime size */
|
|
if (len < 16 || len > 8192) {
|
|
printf("Invalid prime size!\n");
|
|
return CRYPT_INVALID_PRIME_SIZE;
|
|
}
|
|
|
|
/* New prime generation makes the code even more cryptoish-insane. Do you know what this means!!!
|
|
-- Gir: Yeah, oh wait, er, no.
|
|
*/
|
|
return mpi_to_ltc_error(mp_prime_random_ex(N, mp_prime_rabin_miller_trials(len), len, type, rand_prime_helper, NULL));
|
|
}
|
|
|
|
int rsa_make_key(int size, long e, rsa_key *key)
|
|
{
|
|
mp_int p, q, tmp1, tmp2, tmp3;
|
|
int err;
|
|
|
|
if ((size < (MIN_RSA_SIZE/8)) || (size > (MAX_RSA_SIZE/8))) {
|
|
return CRYPT_INVALID_KEYSIZE;
|
|
}
|
|
|
|
if ((e < 3) || ((e & 1) == 0)) {
|
|
return CRYPT_INVALID_ARG;
|
|
}
|
|
|
|
if ((err = mp_init_multi(&p, &q, &tmp1, &tmp2, &tmp3, NULL)) != MP_OKAY) {
|
|
return mpi_to_ltc_error(err);
|
|
}
|
|
|
|
/* make primes p and q (optimization provided by Wayne Scott) */
|
|
if ((err = mp_set_int(&tmp3, e)) != MP_OKAY) { goto error; } /* tmp3 = e */
|
|
|
|
/* make prime "p" */
|
|
do {
|
|
if ((err = rand_prime(&p, size*4)) != CRYPT_OK) { goto done; }
|
|
if ((err = mp_sub_d(&p, 1, &tmp1)) != MP_OKAY) { goto error; } /* tmp1 = p-1 */
|
|
if ((err = mp_gcd(&tmp1, &tmp3, &tmp2)) != MP_OKAY) { goto error; } /* tmp2 = gcd(p-1, e) */
|
|
} while (mp_cmp_d(&tmp2, 1) != 0); /* while e divides p-1 */
|
|
|
|
/* make prime "q" */
|
|
do {
|
|
if ((err = rand_prime(&q, size*4)) != CRYPT_OK) { goto done; }
|
|
if ((err = mp_sub_d(&q, 1, &tmp1)) != MP_OKAY) { goto error; } /* tmp1 = q-1 */
|
|
if ((err = mp_gcd(&tmp1, &tmp3, &tmp2)) != MP_OKAY) { goto error; } /* tmp2 = gcd(q-1, e) */
|
|
} while (mp_cmp_d(&tmp2, 1) != 0); /* while e divides q-1 */
|
|
|
|
/* tmp1 = lcm(p-1, q-1) */
|
|
if ((err = mp_sub_d(&p, 1, &tmp2)) != MP_OKAY) { goto error; } /* tmp2 = p-1 */
|
|
/* tmp1 = q-1 (previous do/while loop) */
|
|
if ((err = mp_lcm(&tmp1, &tmp2, &tmp1)) != MP_OKAY) { goto error; } /* tmp1 = lcm(p-1, q-1) */
|
|
|
|
/* make key */
|
|
if ((err = mp_init_multi(&key->e, &key->d, &key->N, &key->dQ, &key->dP,
|
|
&key->qP, &key->p, &key->q, NULL)) != MP_OKAY) {
|
|
goto error;
|
|
}
|
|
|
|
if ((err = mp_set_int(&key->e, e)) != MP_OKAY) { goto error2; } /* key->e = e */
|
|
if ((err = mp_invmod(&key->e, &tmp1, &key->d)) != MP_OKAY) { goto error2; } /* key->d = 1/e mod lcm(p-1,q-1) */
|
|
if ((err = mp_mul(&p, &q, &key->N)) != MP_OKAY) { goto error2; } /* key->N = pq */
|
|
|
|
/* optimize for CRT now */
|
|
/* find d mod q-1 and d mod p-1 */
|
|
if ((err = mp_sub_d(&p, 1, &tmp1)) != MP_OKAY) { goto error2; } /* tmp1 = q-1 */
|
|
if ((err = mp_sub_d(&q, 1, &tmp2)) != MP_OKAY) { goto error2; } /* tmp2 = p-1 */
|
|
if ((err = mp_mod(&key->d, &tmp1, &key->dP)) != MP_OKAY) { goto error2; } /* dP = d mod p-1 */
|
|
if ((err = mp_mod(&key->d, &tmp2, &key->dQ)) != MP_OKAY) { goto error2; } /* dQ = d mod q-1 */
|
|
if ((err = mp_invmod(&q, &p, &key->qP)) != MP_OKAY) { goto error2; } /* qP = 1/q mod p */
|
|
|
|
if ((err = mp_copy(&p, &key->p)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_copy(&q, &key->q)) != MP_OKAY) { goto error2; }
|
|
|
|
/* shrink ram required */
|
|
if ((err = mp_shrink(&key->e)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_shrink(&key->d)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_shrink(&key->N)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_shrink(&key->dQ)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_shrink(&key->dP)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_shrink(&key->qP)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_shrink(&key->p)) != MP_OKAY) { goto error2; }
|
|
if ((err = mp_shrink(&key->q)) != MP_OKAY) { goto error2; }
|
|
|
|
/* set key type (in this case it's CRT optimized) */
|
|
key->type = PK_PRIVATE;
|
|
|
|
/* return ok and free temps */
|
|
err = CRYPT_OK;
|
|
goto done;
|
|
error2:
|
|
mp_clear_multi(&key->d, &key->e, &key->N, &key->dQ, &key->dP,
|
|
&key->qP, &key->p, &key->q, NULL);
|
|
error:
|
|
err = mpi_to_ltc_error(err);
|
|
done:
|
|
mp_clear_multi(&tmp3, &tmp2, &tmp1, &p, &q, NULL);
|
|
return err;
|
|
}
|
|
|
|
void rsa_free(rsa_key *key)
|
|
{
|
|
mp_clear_multi(&key->e, &key->d, &key->N, &key->dQ, &key->dP,
|
|
&key->qP, &key->p, &key->q, NULL);
|
|
}
|
|
|
|
/* compute an RSA modular exponentiation */
|
|
int rsa_exptmod(const unsigned char *in, unsigned long inlen,
|
|
unsigned char *out, unsigned long *outlen, int which,
|
|
rsa_key *key)
|
|
{
|
|
mp_int tmp, tmpa, tmpb;
|
|
unsigned long x;
|
|
int err;
|
|
|
|
/* is the key of the right type for the operation? */
|
|
if (which == PK_PRIVATE && (key->type != PK_PRIVATE)) {
|
|
return CRYPT_PK_NOT_PRIVATE;
|
|
}
|
|
|
|
/* must be a private or public operation */
|
|
if (which != PK_PRIVATE && which != PK_PUBLIC) {
|
|
return CRYPT_PK_INVALID_TYPE;
|
|
}
|
|
|
|
/* init and copy into tmp */
|
|
if ((err = mp_init_multi(&tmp, &tmpa, &tmpb, NULL)) != MP_OKAY) { return mpi_to_ltc_error(err); }
|
|
if ((err = mp_read_unsigned_bin(&tmp, in, (int)inlen)) != MP_OKAY) { goto error; }
|
|
|
|
/* sanity check on the input */
|
|
if (mp_cmp(&key->N, &tmp) == MP_LT) {
|
|
err = CRYPT_PK_INVALID_SIZE;
|
|
goto done;
|
|
}
|
|
|
|
/* are we using the private exponent and is the key optimized? */
|
|
if (which == PK_PRIVATE) {
|
|
/* tmpa = tmp^dP mod p */
|
|
if ((err = mpi_to_ltc_error(mp_exptmod(&tmp, &key->dP, &key->p, &tmpa))) != MP_OKAY) { goto error; }
|
|
|
|
/* tmpb = tmp^dQ mod q */
|
|
if ((err = mpi_to_ltc_error(mp_exptmod(&tmp, &key->dQ, &key->q, &tmpb))) != MP_OKAY) { goto error; }
|
|
|
|
/* tmp = (tmpa - tmpb) * qInv (mod p) */
|
|
if ((err = mp_sub(&tmpa, &tmpb, &tmp)) != MP_OKAY) { goto error; }
|
|
if ((err = mp_mulmod(&tmp, &key->qP, &key->p, &tmp)) != MP_OKAY) { goto error; }
|
|
|
|
/* tmp = tmpb + q * tmp */
|
|
if ((err = mp_mul(&tmp, &key->q, &tmp)) != MP_OKAY) { goto error; }
|
|
if ((err = mp_add(&tmp, &tmpb, &tmp)) != MP_OKAY) { goto error; }
|
|
} else {
|
|
/* exptmod it */
|
|
if ((err = mp_exptmod(&tmp, &key->e, &key->N, &tmp)) != MP_OKAY) { goto error; }
|
|
}
|
|
|
|
/* read it back */
|
|
x = (unsigned long)mp_unsigned_bin_size(&key->N);
|
|
if (x > *outlen) {
|
|
err = CRYPT_BUFFER_OVERFLOW;
|
|
goto done;
|
|
}
|
|
*outlen = x;
|
|
|
|
/* convert it */
|
|
memset(out, 0, x);
|
|
if ((err = mp_to_unsigned_bin(&tmp, out+(x-mp_unsigned_bin_size(&tmp)))) != MP_OKAY) { goto error; }
|
|
|
|
/* clean up and return */
|
|
err = CRYPT_OK;
|
|
goto done;
|
|
error:
|
|
err = mpi_to_ltc_error(err);
|
|
done:
|
|
mp_clear_multi(&tmp, &tmpa, &tmpb, NULL);
|
|
return err;
|
|
}
|