Commit 7cb79c7a authored Jun 04, 2015 by Matt Caswell

EC_POINT_is_on_curve does not return a boolean



The function EC_POINT_is_on_curve does not return a boolean value.
It returns 1 if the point is on the curve, 0 if it is not, and -1
on error. Many usages within OpenSSL were incorrectly using this
function and therefore not correctly handling error conditions.

With thanks to the Open Crypto Audit Project for reporting this issue.

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(cherry picked from commit 68886be7)

parent d2725992

crypto/ec/ec2_oct.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -387,7 +387,7 @@ int ec_GF2m_simple_oct2point(const EC_GROUP group, EC_POINT point,
		}

		/* test required by X9.62 */
		if (!EC_POINT_is_on_curve(group, point, ctx)) {
		if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
		ECerr(EC_F_EC_GF2M_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
		goto err;
		}

crypto/ec/ec_check.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -85,7 +85,7 @@ int EC_GROUP_check(const EC_GROUP group, BN_CTX ctx)
		ECerr(EC_F_EC_GROUP_CHECK, EC_R_UNDEFINED_GENERATOR);
		goto err;
		}
		if (!EC_POINT_is_on_curve(group, group->generator, ctx)) {
		if (EC_POINT_is_on_curve(group, group->generator, ctx) <= 0) {
		ECerr(EC_F_EC_GROUP_CHECK, EC_R_POINT_IS_NOT_ON_CURVE);
		goto err;
		}

crypto/ec/ec_key.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -314,7 +314,7 @@ int EC_KEY_check_key(const EC_KEY *eckey)
		goto err;

		/* testing whether the pub_key is on the elliptic curve */
		if (!EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx)) {
		if (EC_POINT_is_on_curve(eckey->group, eckey->pub_key, ctx) <= 0) {
		ECerr(EC_F_EC_KEY_CHECK_KEY, EC_R_POINT_IS_NOT_ON_CURVE);
		goto err;
		}

crypto/ec/ec_lib.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -970,6 +970,13 @@ int EC_POINT_is_at_infinity(const EC_GROUP group, const EC_POINT point)
		return group->meth->is_at_infinity(group, point);
		}

		/*
		* Check whether an EC_POINT is on the curve or not. Note that the return
		* value for this function should NOT be treated as a boolean. Return values:
		* 1: The point is on the curve
		* 0: The point is not on the curve
		* -1: An error occurred
		*/
		int EC_POINT_is_on_curve(const EC_GROUP group, const EC_POINT point,
		BN_CTX *ctx)
		{

crypto/ec/ecp_oct.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -413,7 +413,7 @@ int ec_GFp_simple_oct2point(const EC_GROUP group, EC_POINT point,
		}

		/* test required by X9.62 */
		if (!EC_POINT_is_on_curve(group, point, ctx)) {
		if (EC_POINT_is_on_curve(group, point, ctx) <= 0) {
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
		goto err;
		}