PR: 1990

[oweals/openssl.git] / crypto / ec / ec2_smpt.c

diff --git a/crypto/ec/ec2_smpt.c b/crypto/ec/ec2_smpt.c
index 1b014e5d96814ee7819350f2811b88c8357b1c42..72a8d570517f3119686ccdd7f4463d1521aabe96 100644 (file)
--- a/crypto/ec/ec2_smpt.c
+++ b/crypto/ec/ec2_smpt.c
@@ -61,7 +61,8 @@
  * compressed coordinates.  Uses algorithm 2.3.4 of SEC 1. 
  * Note that the simple implementation only uses affine coordinates.
  *
- * This algorithm is patented by Certicom Corp. under US Patent 6,141,420.
+ * This algorithm is patented by Certicom Corp. under US Patent 6,141,420
+ * (for licensing information, contact licensing@certicom.com).
  * This function is disabled by default and can be enabled by defining the 
  * preprocessor macro OPENSSL_EC_BIN_PT_COMP at Configure-time.
  */
@@ -76,6 +77,9 @@ int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *p
        BIGNUM *tmp, *x, *y, *z;
        int ret = 0, z0;
 
+       /* clear error queue */
+       ERR_clear_error();
+
        if (ctx == NULL)
                {
                ctx = new_ctx = BN_CTX_new();
@@ -103,7 +107,19 @@ int ec_GF2m_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *p
                if (!group->meth->field_div(group, tmp, &group->b, tmp, ctx)) goto err;
                if (!BN_GF2m_add(tmp, &group->a, tmp)) goto err;
                if (!BN_GF2m_add(tmp, x, tmp)) goto err;
-               if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx)) goto err;
+               if (!BN_GF2m_mod_solve_quad_arr(z, tmp, group->poly, ctx))
+                       {
+                       unsigned long err = ERR_peek_last_error();
+                       
+                       if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NO_SOLUTION)
+                               {
+                               ERR_clear_error();
+                               ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
+                               }
+                       else
+                               ECerr(EC_F_EC_GF2M_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
+                       goto err;
+                       }
                z0 = (BN_is_odd(z)) ? 1 : 0;
                if (!group->meth->field_mul(group, y, x, z, ctx)) goto err;
                if (z0 != y_bit)