diff --git a/CHANGES b/CHANGES
index 215bda7a1..7707467d3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,9 @@
 
  Changes between 0.9.6 and 0.9.6a  [xx XXX 2001]
 
+  *) Use better test patterns in bntest.
+     [Ulf Möller]
+
   *) Initialise "ex_data" member of RSA/DSA/DH structures prior to calling
      the method-specific "init()" handler. Also clean up ex_data after
      calling the method-specific "finish()" handler. Previously, this was
diff --git a/crypto/bn/bn.h b/crypto/bn/bn.h
index ef1cfb025..b232c2cea 100644
--- a/crypto/bn/bn.h
+++ b/crypto/bn/bn.h
@@ -468,6 +468,8 @@ BN_ULONG bn_sub_words(BN_ULONG *rp, BN_ULONG *ap, BN_ULONG *bp,int num);
 # define bn_dump(a,b)
 #endif
 
+int BN_bntest_rand(BIGNUM *rnd, int bits, int top,int bottom);
+
 /* BEGIN ERROR CODES */
 /* The following lines are auto generated by the script mkerr.pl. Any changes
  * made after this point may be overwritten when the script is next run.
diff --git a/crypto/bn/bn_rand.c b/crypto/bn/bn_rand.c
index 2e45770e8..acd061992 100644
--- a/crypto/bn/bn_rand.c
+++ b/crypto/bn/bn_rand.c
@@ -100,6 +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 != -1)
 		{
 		if (top)
@@ -143,6 +164,13 @@ 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:  0 <= r < range */
 int	BN_rand_range(BIGNUM *r, BIGNUM *range)
 	{
diff --git a/crypto/bn/bntest.c b/crypto/bn/bntest.c
index c9801dc01..af0c2629e 100644
--- a/crypto/bn/bntest.c
+++ b/crypto/bn/bntest.c
@@ -120,9 +120,7 @@ int main(int argc, char *argv[])
 
 	results = 0;
 
-	RAND_seed(rnd_seed, sizeof rnd_seed); /* or BN_rand may fail, and we don't
-	                                       * even check its return value
-	                                       * (which we should) */
+	RAND_seed(rnd_seed, sizeof rnd_seed); /* or BN_generate_prime may fail */
 
 	argc--;
 	argv++;
@@ -251,10 +249,10 @@ int test_add(BIO *bp)
 	BN_init(&b);
 	BN_init(&c);
 
-	BN_rand(&a,512,0,0);
+	BN_bntest_rand(&a,512,0,0);
 	for (i=0; i<num0; i++)
 		{
-		BN_rand(&b,450+i,0,0);
+		BN_bntest_rand(&b,450+i,0,0);
 		a.neg=rand_neg();
 		b.neg=rand_neg();
 		if (bp == NULL)
@@ -303,14 +301,14 @@ int test_sub(BIO *bp)
 		{
 		if (i < num1)
 			{
-			BN_rand(&a,512,0,0);
+			BN_bntest_rand(&a,512,0,0);
 			BN_copy(&b,&a);
 			if (BN_set_bit(&a,i)==0) return(0);
 			BN_add_word(&b,i);
 			}
 		else
 			{
-			BN_rand(&b,400+i-num1,0,0);
+			BN_bntest_rand(&b,400+i-num1,0,0);
 			a.neg=rand_neg();
 			b.neg=rand_neg();
 			}
@@ -360,13 +358,13 @@ int test_div(BIO *bp, BN_CTX *ctx)
 		{
 		if (i < num1)
 			{
-			BN_rand(&a,400,0,0);
+			BN_bntest_rand(&a,400,0,0);
 			BN_copy(&b,&a);
 			BN_lshift(&a,&a,i);
 			BN_add_word(&a,i);
 			}
 		else
-			BN_rand(&b,50+3*(i-num1),0,0);
+			BN_bntest_rand(&b,50+3*(i-num1),0,0);
 		a.neg=rand_neg();
 		b.neg=rand_neg();
 		if (bp == NULL)
@@ -430,13 +428,13 @@ int test_div_recp(BIO *bp, BN_CTX *ctx)
 		{
 		if (i < num1)
 			{
-			BN_rand(&a,400,0,0);
+			BN_bntest_rand(&a,400,0,0);
 			BN_copy(&b,&a);
 			BN_lshift(&a,&a,i);
 			BN_add_word(&a,i);
 			}
 		else
-			BN_rand(&b,50+3*(i-num1),0,0);
+			BN_bntest_rand(&b,50+3*(i-num1),0,0);
 		a.neg=rand_neg();
 		b.neg=rand_neg();
 		BN_RECP_CTX_set(&recp,&b,ctx);
@@ -507,11 +505,11 @@ int test_mul(BIO *bp)
 		{
 		if (i <= num1)
 			{
-			BN_rand(&a,100,0,0);
-			BN_rand(&b,100,0,0);
+			BN_bntest_rand(&a,100,0,0);
+			BN_bntest_rand(&b,100,0,0);
 			}
 		else
-			BN_rand(&b,i-num1,0,0);
+			BN_bntest_rand(&b,i-num1,0,0);
 		a.neg=rand_neg();
 		b.neg=rand_neg();
 		if (bp == NULL)
@@ -560,7 +558,7 @@ int test_sqr(BIO *bp, BN_CTX *ctx)
 
 	for (i=0; i<num0; i++)
 		{
-		BN_rand(&a,40+i*10,0,0);
+		BN_bntest_rand(&a,40+i*10,0,0);
 		a.neg=rand_neg();
 		if (bp == NULL)
 			for (j=0; j<100; j++)
@@ -611,15 +609,15 @@ int test_mont(BIO *bp, BN_CTX *ctx)
 
 	mont=BN_MONT_CTX_new();
 
-	BN_rand(&a,100,0,0); /**/
-	BN_rand(&b,100,0,0); /**/
+	BN_bntest_rand(&a,100,0,0); /**/
+	BN_bntest_rand(&b,100,0,0); /**/
 	for (i=0; i<num2; i++)
 		{
 		int bits = (200*(i+1))/num2;
 
 		if (bits == 0)
 			continue;
-		BN_rand(&n,bits,0,1);
+		BN_bntest_rand(&n,bits,0,1);
 		BN_MONT_CTX_set(mont,&n,ctx);
 
 		BN_to_montgomery(&A,&a,mont,ctx);
@@ -681,10 +679,10 @@ int test_mod(BIO *bp, BN_CTX *ctx)
 	d=BN_new();
 	e=BN_new();
 
-	BN_rand(a,1024,0,0); /**/
+	BN_bntest_rand(a,1024,0,0); /**/
 	for (i=0; i<num0; i++)
 		{
-		BN_rand(b,450+i*10,0,0); /**/
+		BN_bntest_rand(b,450+i*10,0,0); /**/
 		a->neg=rand_neg();
 		b->neg=rand_neg();
 		if (bp == NULL)
@@ -730,11 +728,11 @@ int test_mod_mul(BIO *bp, BN_CTX *ctx)
 	d=BN_new();
 	e=BN_new();
 
-	BN_rand(c,1024,0,0); /**/
+	BN_bntest_rand(c,1024,0,0); /**/
 	for (i=0; i<num0; i++)
 		{
-		BN_rand(a,475+i*10,0,0); /**/
-		BN_rand(b,425+i*11,0,0); /**/
+		BN_bntest_rand(a,475+i*10,0,0); /**/
+		BN_bntest_rand(b,425+i*11,0,0); /**/
 		a->neg=rand_neg();
 		b->neg=rand_neg();
 	/*	if (bp == NULL)
@@ -792,11 +790,11 @@ int test_mod_exp(BIO *bp, BN_CTX *ctx)
 	d=BN_new();
 	e=BN_new();
 
-	BN_rand(c,30,0,1); /* must be odd for montgomery */
+	BN_bntest_rand(c,30,0,1); /* must be odd for montgomery */
 	for (i=0; i<num2; i++)
 		{
-		BN_rand(a,20+i*5,0,0); /**/
-		BN_rand(b,2+i,0,0); /**/
+		BN_bntest_rand(a,20+i*5,0,0); /**/
+		BN_bntest_rand(b,2+i,0,0); /**/
 
 		if (!BN_mod_exp(d,a,b,c,ctx))
 			return(00);
@@ -846,8 +844,8 @@ int test_exp(BIO *bp, BN_CTX *ctx)
 
 	for (i=0; i<num2; i++)
 		{
-		BN_rand(a,20+i*5,0,0); /**/
-		BN_rand(b,2+i,0,0); /**/
+		BN_bntest_rand(a,20+i*5,0,0); /**/
+		BN_bntest_rand(b,2+i,0,0); /**/
 
 		if (!BN_exp(d,a,b,ctx))
 			return(00);
@@ -897,7 +895,7 @@ int test_lshift(BIO *bp,BN_CTX *ctx,BIGNUM *a_)
 	else
 	    {
 	    a=BN_new();
-	    BN_rand(a,200,0,0); /**/
+	    BN_bntest_rand(a,200,0,0); /**/
 	    a->neg=rand_neg();
 	    }
 	for (i=0; i<num0; i++)
@@ -949,7 +947,7 @@ int test_lshift1(BIO *bp)
 	b=BN_new();
 	c=BN_new();
 
-	BN_rand(a,200,0,0); /**/
+	BN_bntest_rand(a,200,0,0); /**/
 	a->neg=rand_neg();
 	for (i=0; i<num0; i++)
 		{
@@ -993,7 +991,7 @@ int test_rshift(BIO *bp,BN_CTX *ctx)
 	e=BN_new();
 	BN_one(c);
 
-	BN_rand(a,200,0,0); /**/
+	BN_bntest_rand(a,200,0,0); /**/
 	a->neg=rand_neg();
 	for (i=0; i<num0; i++)
 		{
@@ -1036,7 +1034,7 @@ int test_rshift1(BIO *bp)
 	b=BN_new();
 	c=BN_new();
 
-	BN_rand(a,200,0,0); /**/
+	BN_bntest_rand(a,200,0,0); /**/
 	a->neg=rand_neg();
 	for (i=0; i<num0; i++)
 		{