- {
- unsigned char *buf=NULL;
- int ret=0,bit,bytes,mask;
- time_t tim;
-
- if (bits == 0)
- {
- BN_zero(rnd);
- return 1;
- }
-
- bytes=(bits+7)/8;
- bit=(bits-1)%8;
- mask=0xff<<bit;
-
- buf=(unsigned char *)OPENSSL_malloc(bytes);
- if (buf == NULL)
- {
- BNerr(BN_F_BN_RAND,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);
-
- if (pseudorand)
- {
- if (RAND_pseudo_bytes(buf, bytes) == -1)
- goto err;
- }
- else
- {
- if (RAND_bytes(buf, bytes) <= 0)
- goto err;
- }
-
-#if 1
- if (pseudorand == 2)
- {
- /* generate patterns that are more likely to trigger BN
- library bugs */
- int i;
- unsigned char c;
-
- for (i = 0; i < bytes; i++)
- {
- RAND_pseudo_bytes(&c, 1);
- if (c >= 128 && i > 0)
- buf[i] = buf[i-1];
- else if (c < 42)
- buf[i] = 0;
- else if (c < 84)
- buf[i] = 255;
- }
- }
-#endif
-
- if (top)
- {
- if (bit == 0)
- {
- buf[0]=1;
- buf[1]|=0x80;
- }
- else
- {
- buf[0]|=(3<<(bit-1));
- buf[0]&= ~(mask<<1);
- }
- }
- else
- {
- buf[0]|=(1<<bit);
- buf[0]&= ~(mask<<1);
- }
- if (bottom) /* set bottom bits to whatever odd is */
- buf[bytes-1]|=1;
- if (!BN_bin2bn(buf,bytes,rnd)) goto err;
- ret=1;
-err:
- if (buf != NULL)
- {
- memset(buf,0,bytes);
- OPENSSL_free(buf);
- }
- return(ret);
- }
-
-int BN_rand(BIGNUM *rnd, int bits, int top, int bottom)
- {
- return bnrand(0, rnd, bits, top, bottom);
- }
-
-int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom)
- {
- return bnrand(1, rnd, bits, top, bottom);
- }
-
-#if 1
-int BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom)
- {
- return bnrand(2, rnd, bits, top, bottom);
- }
-#endif
+{
+ unsigned char *buf = NULL;
+ int ret = 0, bit, bytes, mask;
+ time_t tim;
+
+ if (bits < 0 || (bits == 1 && top > 0)) {
+ BNerr(BN_F_BNRAND, BN_R_BITS_TOO_SMALL);
+ return 0;
+ }
+
+ if (bits == 0) {
+ BN_zero(rnd);
+ return 1;
+ }
+
+ bytes = (bits + 7) / 8;
+ bit = (bits - 1) % 8;
+ mask = 0xff << (bit + 1);
+
+ buf = OPENSSL_malloc(bytes);
+ if (buf == NULL) {
+ 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), 0.0);
+
+ if (pseudorand) {
+ if (RAND_bytes(buf, bytes) <= 0)
+ goto err;
+ } else {
+ if (RAND_bytes(buf, bytes) <= 0)
+ goto err;
+ }
+
+ if (pseudorand == 2) {
+ /*
+ * generate patterns that are more likely to trigger BN library bugs
+ */
+ int i;
+ unsigned char c;
+
+ for (i = 0; i < bytes; i++) {
+ if (RAND_bytes(&c, 1) <= 0)
+ goto err;
+ if (c >= 128 && i > 0)
+ buf[i] = buf[i - 1];
+ else if (c < 42)
+ buf[i] = 0;
+ else if (c < 84)
+ buf[i] = 255;
+ }
+ }
+
+ if (top >= 0) {
+ if (top) {
+ if (bit == 0) {
+ buf[0] = 1;
+ buf[1] |= 0x80;
+ } else {
+ buf[0] |= (3 << (bit - 1));
+ }
+ } else {
+ buf[0] |= (1 << bit);
+ }
+ }
+ buf[0] &= ~mask;
+ if (bottom) /* set bottom bit if requested */
+ buf[bytes - 1] |= 1;
+ if (!BN_bin2bn(buf, bytes, rnd))
+ goto err;
+ ret = 1;
+ err:
+ OPENSSL_clear_free(buf, bytes);
+ bn_check_top(rnd);
+ return (ret);
+}
+
+int BN_rand(BIGNUM *rnd, int bits, int top, int bottom)
+{
+ return bnrand(0, rnd, bits, top, bottom);
+}
+
+int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom)
+{
+ return bnrand(1, rnd, bits, top, bottom);
+}
+
+int BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom)
+{
+ return bnrand(2, rnd, bits, top, bottom);
+}
+
+/* random number r: 0 <= r < 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)) {
+ BNerr(BN_F_BN_RAND_RANGE, BN_R_INVALID_RANGE);
+ return 0;
+ }
+
+ n = BN_num_bits(range); /* n > 0 */
+
+ /* BN_is_bit_set(range, n - 1) always holds */
+
+ 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;
+
+ k_bytes = OPENSSL_malloc(num_k_bytes);
+ if (k_bytes == NULL)
+ 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:
+ OPENSSL_free(k_bytes);
+ return ret;
+}