-/* crypto/bn/bn_mod.c */
+/* crypto/bn/bn_sqrt.c */
/* Written by Lenka Fibikova <fibikova@exp-math.uni-essen.de>
* and Bodo Moeller for the OpenSSL project. */
/* ====================================================================
* using the Tonelli/Shanks algorithm (cf. Henri Cohen, "A Course
* in Algebraic Computational Number Theory", algorithm 1.5.1).
* 'p' must be prime!
- * If 'a' is not a square, this is not necessarily detected by
- * the algorithms; a bogus result must be expected in this case.
*/
{
BIGNUM *ret = in;
goto end;
if (!BN_set_word(ret, BN_is_bit_set(a, 0)))
{
- BN_free(ret);
+ if (ret != in)
+ BN_free(ret);
return NULL;
}
+ bn_check_top(ret);
return ret;
}
goto end;
if (!BN_set_word(ret, BN_is_one(a)))
{
- BN_free(ret);
+ if (ret != in)
+ BN_free(ret);
return NULL;
}
+ bn_check_top(ret);
return ret;
}
if (BN_is_zero(t))
{
/* special case: a == 0 (mod p) */
- if (!BN_zero(ret)) goto end;
+ BN_zero(ret);
err = 0;
goto end;
}
if (BN_is_zero(x))
{
/* special case: a == 0 (mod p) */
- if (!BN_zero(ret)) goto end;
+ BN_zero(ret);
err = 0;
goto end;
}
ret = NULL;
}
BN_CTX_end(ctx);
+ bn_check_top(ret);
return ret;
}