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diff --git a/crypto/ec/ecp_smpl.c b/crypto/ec/ecp_smpl.c
index 7325abf52055b4b2e5b9a6e3fc721d9df6b422c8..267134af4b5e5c61593e49fb8ee883065ab60c29 100644 (file)
--- a/crypto/ec/ecp_smpl.c
+++ b/crypto/ec/ecp_smpl.c
@@ -112,6 +112,20 @@ const EC_METHOD *EC_GFp_simple_method(void)
        }
 
 
+/* Most method functions in this file are designed to work with
+ * non-trivial representations of field elements if necessary
+ * (see ecp_mont.c): while standard modular addition and subtraction
+ * are used, the field_mul and field_sqr methods will be used for
+ * multiplication, and field_encode and field_decode (if defined)
+ * will be used for converting between representations.
+
+ * Functions ec_GFp_simple_points_make_affine() and
+ * ec_GFp_simple_point_get_affine_coordinates() specifically assume
+ * that if a non-trivial representation is used, it is a Montgomery
+ * representation (i.e. 'encoding' means multiplying by some factor R).
+ */
+
+
 int ec_GFp_simple_group_init(EC_GROUP *group)
        {
        BN_init(&group->field);