Add _raw function to P256K1

Modified the testing to use the generic fast reduction test function.

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>

library/ecp_curves.c

@@ -4623,7 +4623,7 @@ int mbedtls_ecp_mod_p224k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 static int ecp_mod_p256k1(mbedtls_mpi *);
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p256k1(mbedtls_mpi *);
+int mbedtls_ecp_mod_p256k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 #endif
 
 #if defined(ECP_LOAD_GROUP)
@@ -5680,30 +5680,31 @@ int mbedtls_ecp_mod_p224k1_raw(mbedtls_mpi_uint *X, size_t X_limbs)
 
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 
+/*
+ * Fast quasi-reduction modulo p256k1 = 2^256 - R,
+ * with R = 2^32 + 2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1 = 0x01000003D1
+ */
 static int ecp_mod_p256k1(mbedtls_mpi *N)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t expected_width = 2 * ((256 + biL - 1) / biL);
     MBEDTLS_MPI_CHK(mbedtls_mpi_grow(N, expected_width));
-    ret = mbedtls_ecp_mod_p256k1(N);
+    ret = mbedtls_ecp_mod_p256k1_raw(N->p, expected_width);
 
 cleanup:
     return ret;
 }
 
-/*
- * Fast quasi-reduction modulo p256k1 = 2^256 - R,
- * with R = 2^32 + 2^9 + 2^8 + 2^7 + 2^6 + 2^4 + 1 = 0x01000003D1
- */
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p256k1(mbedtls_mpi *N)
+int mbedtls_ecp_mod_p256k1_raw(mbedtls_mpi_uint *X, size_t X_limbs)
 {
     static mbedtls_mpi_uint Rp[] = {
-        MBEDTLS_BYTES_TO_T_UINT_8(0xD1, 0x03, 0x00, 0x00, 0x01, 0x00, 0x00,
+        MBEDTLS_BYTES_TO_T_UINT_8(0xD1, 0x03, 0x00, 0x00,
-                                  0x00)
+                                  0x01, 0x00, 0x00, 0x00)
     };
-    return ecp_mod_koblitz(N->p, N->n, Rp, 256);
+    return ecp_mod_koblitz(X, X_limbs, Rp, 256);
 }
+
 #endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
 
 #if defined(MBEDTLS_TEST_HOOKS)

library/ecp_invasive.h

@@ -190,7 +190,7 @@ int mbedtls_ecp_mod_p224k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 
 MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p256k1(mbedtls_mpi *N);
+int mbedtls_ecp_mod_p256k1_raw(mbedtls_mpi_uint *X, size_t X_limbs);
 
 #endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
 

scripts/mbedtls_dev/ecp.py

@@ -639,8 +639,8 @@ class EcpP256K1Raw(bignum_common.ModOperationCommon,
                    EcpTarget):
     """Test cases for ECP P256 fast reduction."""
     symbol = "-"
-    test_function = "ecp_mod_p256k1"
+    test_function = "ecp_mod_p_generic_raw"
-    test_name = "ecp_mod_p256k1"
+    test_name = "ecp_mod_p256k1_raw"
     input_style = "fixed"
     arity = 1
     dependencies = ["MBEDTLS_ECP_DP_SECP256K1_ENABLED"]
@@ -659,9 +659,13 @@ class EcpP256K1Raw(bignum_common.ModOperationCommon,
         # 2^256 - 1
         "ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff",
 
-        # Maximum canonical P256 multiplication result
+        # Maximum canonical P256K1 multiplication result
-        ("fffffffffffffffffffffffffffffffffffffffffffffffffffffffdfffff85c0"
+        ("fffffffffffffffffffffffffffffffffffffffffffffffffffffffdfffff85c"
-         "00000000000000000000000000000000000000000000001000007a4000e9844"),
+         "000000000000000000000000000000000000000000000001000007a4000e9844"),
+
+        # Test case for overflow during addition
+        ("0000fffffc2f000e90a0c86a0a63234e5ba641f43a7e4aecc4040e67ec850562"
+         "00000000000000000000000000000000000000000000000000000000585674fd"),
 
         # Test case for overflow during addition
         ("0000fffffc2f000e90a0c86a0a63234e5ba641f43a7e4aecc4040e67ec850562"
@@ -702,6 +706,10 @@ class EcpP256K1Raw(bignum_common.ModOperationCommon,
     def is_valid(self) -> bool:
         return True
 
+    def arguments(self):
+        args = super().arguments()
+        return  ["MBEDTLS_ECP_DP_SECP256K1"] + args
+
 
 class EcpP448Raw(bignum_common.ModOperationCommon,
                  EcpTarget):

tests/suites/test_suite_ecp.function

@@ -1341,6 +1341,13 @@ void ecp_mod_p_generic_raw(int curve_id,
             curve_bits = 224;
             curve_func = &mbedtls_ecp_mod_p224k1_raw;
             break;
+#endif
+#if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
+        case MBEDTLS_ECP_DP_SECP256K1:
+            limbs = 2 * limbs_N;
+            curve_bits = 256;
+            curve_func = &mbedtls_ecp_mod_p256k1_raw;
+            break;
 #endif
         default:
             mbedtls_test_fail("Unsupported curve_id", __LINE__, __FILE__);
@@ -1369,46 +1376,6 @@ exit:
 }
 /* END_CASE */
 
-
-/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_DP_SECP256K1_ENABLED */
-void ecp_mod_p256k1(char *input_N,
-                    char *input_X,
-                    char *result)
-{
-    mbedtls_mpi X;
-    mbedtls_mpi N;
-    mbedtls_mpi res;
-
-    mbedtls_mpi_init(&X);
-    mbedtls_mpi_init(&N);
-    mbedtls_mpi_init(&res);
-
-    TEST_EQUAL(mbedtls_test_read_mpi(&X,   input_X), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&N,   input_N), 0);
-    TEST_EQUAL(mbedtls_test_read_mpi(&res, result),  0);
-
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, X.p, X.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, N.p, N.n));
-    TEST_ASSERT(mbedtls_mpi_core_uint_le_mpi(0, res.p, res.n));
-
-    size_t limbs = N.n;
-    size_t bytes = limbs * sizeof(mbedtls_mpi_uint);
-
-    TEST_LE_U(X.n, 2 * limbs);
-    TEST_EQUAL(res.n, limbs);
-
-    TEST_EQUAL(mbedtls_ecp_mod_p256k1(&X), 0);
-    TEST_EQUAL(mbedtls_mpi_mod_mpi(&X, &X, &N), 0);
-    TEST_LE_U(mbedtls_mpi_core_bitlen(X.p, X.n), 256);
-    ASSERT_COMPARE(X.p, bytes, res.p, bytes);
-
-exit:
-    mbedtls_mpi_free(&X);
-    mbedtls_mpi_free(&N);
-    mbedtls_mpi_free(&res);
-}
-/* END_CASE */
-
 /* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_DP_CURVE448_ENABLED */
 void ecp_mod_p448(char *input_N,
                   char *input_X,