Check the return from BN_sub() in BN_X931_generate_Xpq().
@@ -184,8 +184,10 @@ int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx)
for (i = 0; i < 1000; i++) {
if (!BN_priv_rand(Xq, nbits, BN_RAND_TOP_TWO, BN_RAND_BOTTOM_ANY))
goto err;
+
/* Check that |Xp - Xq| > 2^(nbits - 100) */
- BN_sub(t, Xp, Xq);
+ if (!BN_sub(t, Xp, Xq))
+ goto err;
if (BN_num_bits(t) > (nbits - 100))
break;
}
