X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_rand.c;h=3873eac6896678c46fcfc925889200e134fbb26b;hp=b1163f7ec44172078a4a15564862db72ed752233;hb=395258457182fcfe4ee6f82ee9c74b5d2f3426c8;hpb=26a3a48d65c7464b400ec1de439994d7f0d25fed

diff --git a/crypto/bn/bn_rand.c b/crypto/bn/bn_rand.c
index b1163f7ec4..3873eac689 100644
--- a/crypto/bn/bn_rand.c
+++ b/crypto/bn/bn_rand.c
@@ -68,6 +68,12 @@ static int bnrand(int pseudorand, BIGNUM *rnd, int bits, int top, int bottom)
 	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;
@@ -94,6 +100,27 @@ static int bnrand(int pseudorand, BIGNUM *rnd, int bits, int top, int bottom)
 			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)
@@ -134,3 +161,66 @@ 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
+
+/* random number r: min <= r < min+range */
+int	BN_rand_range(BIGNUM *r, BIGNUM *min, BIGNUM *range)
+	{
+	int n;
+
+	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 */
+
+	if (n == 1)
+		{
+		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, 0, 0)) return 0;
+			}
+		while (BN_cmp(r, range) >= 0);
+		}
+	else
+		{
+		/* range = 10..._2,
+		 * so  3*range (= 11..._2)  is exactly one bit longer than  range */
+		do
+			{
+			if (!BN_rand(r, n + 1, 0, 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;
+				}
+			}
+		while (BN_cmp(r, range) >= 0);
+		}
+
+	if (min != NULL)
+		{
+		if (!BN_add(r, r, min)) return 0;
+		}
+	
+	return 1;
+	}