- if (n == 1)
- BN_zero(r);
- else if (!BN_is_bit_set(range, n - 2) && !BN_is_bit_set(range, n - 3))
- {
- /* range = 100..._2,
- * so 3*range (= 11..._2) is exactly one bit longer than range */
- do
- {
- if (!bn_rand(r, n + 1, -1, 0)) return 0;
- /* If r < 3*range, use r := r MOD range
- * (which is either r, r - range, or r - 2*range).
- * Otherwise, iterate once more.
- * Since 3*range = 11..._2, each iteration succeeds with
- * probability >= .75. */
- if (BN_cmp(r ,range) >= 0)
- {
- if (!BN_sub(r, r, range)) return 0;
- 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, const BIGNUM *range)
+{
+ return bn_rand_range(0, r, range);
+}
+
+int BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range)
+{
+ return bn_rand_range(1, r, range);
+}
+
+/*
+ * 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;