Merge pull request #7490 from paul-elliott-arm/test_ecp_mod_p448

[Bignum] Add unit tests for ecp_mod_p448

library/ecp_curves.c

@@ -4605,6 +4605,8 @@ static int ecp_mod_p255(mbedtls_mpi *);
 #endif
 #if defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
 static int ecp_mod_p448(mbedtls_mpi *);
+MBEDTLS_STATIC_TESTABLE
+int mbedtls_ecp_mod_p448(mbedtls_mpi *);
 #endif
 #if defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
 static int ecp_mod_p192k1(mbedtls_mpi *);
@@ -5449,6 +5451,11 @@ static int ecp_mod_p255(mbedtls_mpi *N)
 #define P224_WIDTH_MAX   DIV_ROUND_UP(28, sizeof(mbedtls_mpi_uint))
 #define P224_UNUSED_BITS ((P224_WIDTH_MAX * sizeof(mbedtls_mpi_uint) * 8) - 224)
 
+static int ecp_mod_p448(mbedtls_mpi *N)
+{
+    return mbedtls_ecp_mod_p448(N);
+}
+
 /*
  * Fast quasi-reduction modulo p448 = 2^448 - 2^224 - 1
  * Write N as A0 + 2^448 A1 and A1 as B0 + 2^224 B1, and return
@@ -5460,7 +5467,8 @@ static int ecp_mod_p255(mbedtls_mpi *N)
  * but for 64-bit targets it should use half the number of operations if we do
  * the reduction with 224-bit limbs, since mpi_add_mpi will then use 64-bit adds.
  */
-static int ecp_mod_p448(mbedtls_mpi *N)
+MBEDTLS_STATIC_TESTABLE
+int mbedtls_ecp_mod_p448(mbedtls_mpi *N)
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t i;

library/ecp_invasive.h

@@ -193,6 +193,13 @@ int mbedtls_ecp_mod_p256k1(mbedtls_mpi *N);
 
 #endif /* MBEDTLS_ECP_DP_SECP256K1_ENABLED */
 
+#if defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
+
+MBEDTLS_STATIC_TESTABLE
+int mbedtls_ecp_mod_p448(mbedtls_mpi *N);
+
+#endif /* MBEDTLS_ECP_DP_CURVE448_ENABLED */
+
 /** Initialise a modulus with hard-coded const curve data.
  *
  * \note            The caller is responsible for the \p N modulus' memory.

scripts/mbedtls_dev/ecp.py

@@ -682,3 +682,92 @@ class EcpP256K1Raw(bignum_common.ModOperationCommon,
     @property
     def is_valid(self) -> bool:
         return True
+
+
+class EcpP448Raw(bignum_common.ModOperationCommon,
+                 EcpTarget):
+    """Test cases for ECP P448 fast reduction."""
+    symbol = "-"
+    test_function = "ecp_mod_p448"
+    test_name = "ecp_mod_p448"
+    input_style = "fixed"
+    arity = 1
+    dependencies = ["MBEDTLS_ECP_DP_CURVE448_ENABLED"]
+
+    moduli = [("fffffffffffffffffffffffffffffffffffffffffffffffffffffffe"
+               "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff")] # type: List[str]
+
+    input_values = [
+        "0", "1",
+
+        # Modulus - 1
+        ("fffffffffffffffffffffffffffffffffffffffffffffffffffffffe"
+         "fffffffffffffffffffffffffffffffffffffffffffffffffffffffe"),
+
+        # Modulus + 1
+        ("ffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+         "00000000000000000000000000000000000000000000000000000000"),
+
+        # 2^448 - 1
+        ("ffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+         "ffffffffffffffffffffffffffffffffffffffffffffffffffffffff"),
+
+        # Maximum canonical P448 multiplication result
+        ("fffffffffffffffffffffffffffffffffffffffffffffffffffffffd"
+         "fffffffffffffffffffffffffffffffffffffffffffffffffffffffd"
+         "00000000000000000000000000000000000000000000000000000004"
+         "00000000000000000000000000000000000000000000000000000004"),
+
+        # First 8 number generated by random.getrandbits(896) - seed(2,2)
+        ("74667bffe202849da9643a295a9ac6decbd4d3e2d4dec9ef83f0be4e"
+         "80371eb97f81375eecc1cb6347733e847d718d733ff98ff387c56473"
+         "a7a83ee0761ebfd2bd143fa9b714210c665d7435c1066932f4767f26"
+         "294365b2721dea3bf63f23d0dbe53fcafb2147df5ca495fa5a91c89b"),
+        ("4da4daeb4f3f87777ad1f45ae9500ec9c5e2486c44a4a8f69dc8db48"
+         "e86ec9c6e06f291b2a838af8d5c44a4eb3172062d08f1bb2531d6460"
+         "f0caeef038c89b38a8acb5137c9260dc74e088a9b9492f258ebdbfe3"
+         "eb9ac688b9d39cca91551e8259cc60b17604e4b4e73695c3e652c71a"),
+        ("bc1b00d92838e766ef9b6bf2d037fe2e20b6a8464174e75a5f834da7"
+         "0569c018eb2b5693babb7fbb0a76c196067cfdcb11457d9cf45e2fa0"
+         "1d7f4275153924800600571fac3a5b263fdf57cd2c0064975c374746"
+         "5cc36c270e8a35b10828d569c268a20eb78ac332e5e138e26c4454b9"),
+        ("8d2f527e72daf0a54ef25c0707e338687d1f71575653a45c49390aa5"
+         "1cf5192bbf67da14be11d56ba0b4a2969d8055a9f03f2d71581d8e83"
+         "0112ff0f0948eccaf8877acf26c377c13f719726fd70bddacb4deeec"
+         "0b0c995e96e6bc4d62b47204007ee4fab105d83e85e951862f0981ae"),
+        ("84ae65e920a63ac1f2b64df6dff07870c9d531ae72a47403063238da"
+         "1a1fe3f9d6a179fa50f96cd4aff9261aa92c0e6f17ec940639bc2ccd"
+         "f572df00790813e32748dd1db4917fc09f20dbb0dcc93f0e66dfe717"
+         "c17313394391b6e2e6eacb0f0bb7be72bd6d25009aeb7fa0c4169b14"),
+        ("2bb3b36f29421c4021b7379f0897246a40c270b00e893302aba9e7b8"
+         "23fc5ad2f58105748ed5d1b7b310b730049dd332a73fa0b26b75196c"
+         "f87eb8a09b27ec714307c68c425424a1574f1eedf5b0f16cdfdb8394"
+         "24d201e653f53d6883ca1c107ca6e706649889c0c7f3860895bfa813"),
+        ("af3f5d7841b1256d5c1dc12fb5a1ae519fb8883accda6559caa538a0"
+         "9fc9370d3a6b86a7975b54a31497024640332b0612d4050771d7b14e"
+         "b6c004cc3b8367dc3f2bb31efe9934ad0809eae3ef232a32b5459d83"
+         "fbc46f1aea990e94821d46063b4dbf2ca294523d74115c86188b1044"),
+        ("7430051376e31f5aab63ad02854efa600641b4fa37a47ce41aeffafc"
+         "3b45402ac02659fe2e87d4150511baeb198ababb1a16daff3da95cd2"
+         "167b75dfb948f82a8317cba01c75f67e290535d868a24b7f627f2855"
+         "09167d4126af8090013c3273c02c6b9586b4625b475b51096c4ad652"),
+
+        # Next 2 number generated by random.getrandbits(448)
+        ("8f54f8ceacaab39e83844b40ffa9b9f15c14bc4a829e07b0829a48d4"
+         "22fe99a22c70501e533c91352d3d854e061b90303b08c6e33c729578"),
+        ("97eeab64ca2ce6bc5d3fd983c34c769fe89204e2e8168561867e5e15"
+         "bc01bfce6a27e0dfcbf8754472154e76e4c11ab2fec3f6b32e8d4b8a"),
+
+    ]
+
+    @property
+    def arg_a(self) -> str:
+        return super().format_arg('{:x}'.format(self.int_a)).zfill(2 * self.hex_digits)
+
+    def result(self) -> List[str]:
+        result = self.int_a % self.int_n
+        return [self.format_result(result)]
+
+    @property
+    def is_valid(self) -> bool:
+        return True

tests/suites/test_suite_ecp.function

@@ -1472,6 +1472,45 @@ exit:
 }
 /* END_CASE */
 
+/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_DP_CURVE448_ENABLED */
+void ecp_mod_p448(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_p448(&X), 0);
+    TEST_EQUAL(mbedtls_mpi_mod_mpi(&X, &X, &N), 0);
+    TEST_LE_U(mbedtls_mpi_core_bitlen(X.p, X.n), 448);
+    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 */
 void ecp_mod_setup(char *input_A, int id, int ctype, int iret)
 {