*
*/
+#define OPENSSL_FIPSAPI
+
#include <stdio.h>
#include <time.h>
#include "cryptlib.h"
#include "bn_lcl.h"
#include <openssl/rand.h>
+#include <openssl/sha.h>
static int bnrand(int pseudorand, BIGNUM *rnd, int bits, int top, int bottom)
{
buf=(unsigned char *)OPENSSL_malloc(bytes);
if (buf == NULL)
{
- BNerr(BN_F_BN_RAND,ERR_R_MALLOC_FAILURE);
+ BNerr(BN_F_BNRAND,ERR_R_MALLOC_FAILURE);
goto err;
}
/* make a random number and set the top and bottom bits */
time(&tim);
- RAND_add(&tim,sizeof(tim),0);
+ RAND_add(&tim,sizeof(tim),0.0);
if (pseudorand)
{
err:
if (buf != NULL)
{
- memset(buf,0,bytes);
+ OPENSSL_cleanse(buf,bytes);
OPENSSL_free(buf);
}
+ bn_check_top(rnd);
return(ret);
}
/* random number r: 0 <= r < range */
-static int bn_rand_range(int pseudo, BIGNUM *r, BIGNUM *range)
+static int bn_rand_range(int pseudo, BIGNUM *r, const BIGNUM *range)
{
int (*bn_rand)(BIGNUM *, int, int, int) = pseudo ? BN_pseudo_rand : BN_rand;
int n;
+ int count = 100;
if (range->neg || BN_is_zero(range))
{
n = BN_num_bits(range); /* n > 0 */
+ /* BN_is_bit_set(range, n - 1) always holds */
+
if (n == 1)
+ BN_zero(r);
+#ifdef OPENSSL_FIPS
+ /* FIPS 186-3 is picky about how random numbers for keys etc are
+ * generated. So we just use the second case which is equivalent to
+ * "Generation by Testing Candidates" mentioned in B.1.2 et al.
+ */
+ else if (!FIPS_module_mode() && !BN_is_bit_set(range, n - 2) && !BN_is_bit_set(range, n - 3))
+#else
+ else if (!BN_is_bit_set(range, n - 2) && !BN_is_bit_set(range, n - 3))
+#endif
{
- if (!BN_zero(r)) return 0;
- }
- else if (BN_is_bit_set(range, n - 2))
- {
- do
- {
- /* range = 11..._2, so each iteration succeeds with probability >= .75 */
- if (!bn_rand(r, n, -1, 0)) return 0;
- }
- while (BN_cmp(r, range) >= 0);
- }
- else
- {
- /* range = 10..._2,
+ /* range = 100..._2,
* so 3*range (= 11..._2) is exactly one bit longer than range */
do
{
if (BN_cmp(r, range) >= 0)
if (!BN_sub(r, r, range)) return 0;
}
+
+ if (!--count)
+ {
+ BNerr(BN_F_BN_RAND_RANGE, BN_R_TOO_MANY_ITERATIONS);
+ return 0;
+ }
+
}
while (BN_cmp(r, range) >= 0);
}
+ else
+ {
+ do
+ {
+ /* range = 11..._2 or range = 101..._2 */
+ if (!bn_rand(r, n, -1, 0)) return 0;
+ if (!--count)
+ {
+ BNerr(BN_F_BN_RAND_RANGE, BN_R_TOO_MANY_ITERATIONS);
+ return 0;
+ }
+ }
+ while (BN_cmp(r, range) >= 0);
+ }
+
+ bn_check_top(r);
return 1;
}
-int BN_rand_range(BIGNUM *r, BIGNUM *range)
+int BN_rand_range(BIGNUM *r, const BIGNUM *range)
{
return bn_rand_range(0, r, range);
}
-int BN_pseudo_rand_range(BIGNUM *r, BIGNUM *range)
+int BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range)
{
return bn_rand_range(1, r, range);
}
+
+#ifndef OPENSSL_NO_SHA512
+/* BN_generate_dsa_nonce generates a random number 0 <= out < range. Unlike
+ * BN_rand_range, it also includes the contents of |priv| and |message| in the
+ * generation so that an RNG failure isn't fatal as long as |priv| remains
+ * secret. This is intended for use in DSA and ECDSA where an RNG weakness
+ * leads directly to private key exposure unless this function is used. */
+int BN_generate_dsa_nonce(BIGNUM *out, const BIGNUM *range, const BIGNUM* priv,
+ const unsigned char *message, size_t message_len,
+ BN_CTX *ctx)
+ {
+ SHA512_CTX sha;
+ /* We use 512 bits of random data per iteration to
+ * ensure that we have at least |range| bits of randomness. */
+ unsigned char random_bytes[64];
+ unsigned char digest[SHA512_DIGEST_LENGTH];
+ unsigned done, todo;
+ /* We generate |range|+8 bytes of random output. */
+ const unsigned num_k_bytes = BN_num_bytes(range) + 8;
+ unsigned char private_bytes[96];
+ unsigned char *k_bytes;
+ int ret = 0;
+
+ k_bytes = OPENSSL_malloc(num_k_bytes);
+ if (!k_bytes)
+ goto err;
+
+ /* We copy |priv| into a local buffer to avoid exposing its length. */
+ todo = sizeof(priv->d[0])*priv->top;
+ if (todo > sizeof(private_bytes))
+ {
+ /* No reasonable DSA or ECDSA key should have a private key
+ * this large and we don't handle this case in order to avoid
+ * leaking the length of the private key. */
+ BNerr(BN_F_BN_GENERATE_DSA_NONCE, BN_R_PRIVATE_KEY_TOO_LARGE);
+ goto err;
+ }
+ memcpy(private_bytes, priv->d, todo);
+ memset(private_bytes + todo, 0, sizeof(private_bytes) - todo);
+
+ for (done = 0; done < num_k_bytes;) {
+ if (RAND_bytes(random_bytes, sizeof(random_bytes)) != 1)
+ goto err;
+ SHA512_Init(&sha);
+ SHA512_Update(&sha, &done, sizeof(done));
+ SHA512_Update(&sha, private_bytes, sizeof(private_bytes));
+ SHA512_Update(&sha, message, message_len);
+ SHA512_Update(&sha, random_bytes, sizeof(random_bytes));
+ SHA512_Final(digest, &sha);
+
+ todo = num_k_bytes - done;
+ if (todo > SHA512_DIGEST_LENGTH)
+ todo = SHA512_DIGEST_LENGTH;
+ memcpy(k_bytes + done, digest, todo);
+ done += todo;
+ }
+
+ if (!BN_bin2bn(k_bytes, num_k_bytes, out))
+ goto err;
+ if (BN_mod(out, out, range, ctx) != 1)
+ goto err;
+ ret = 1;
+
+err:
+ if (k_bytes)
+ OPENSSL_free(k_bytes);
+ return ret;
+ }
+#endif /* OPENSSL_NO_SHA512 */
projects / openssl.git / blobdiff