ecp_curves: Minor rework for p384
This patch adjusts formatting, documentation and testing.
Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index 179016b..c23ff2c 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -4586,7 +4586,7 @@
#if defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
static int ecp_mod_p384(mbedtls_mpi *);
MBEDTLS_STATIC_TESTABLE
-int mbedtls_ecp_mod_p384_raw(mbedtls_mpi_uint *N_p, size_t N_n);
+int mbedtls_ecp_mod_p384_raw(mbedtls_mpi_uint *X, size_t X_limbs);
#endif
#if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
static int ecp_mod_p521(mbedtls_mpi *);
@@ -5207,69 +5207,70 @@
INIT(384);
ADD(12); ADD(21); ADD(20);
- SUB(23); NEXT; // A0
+ SUB(23); NEXT; // A0
ADD(13); ADD(22); ADD(23);
- SUB(12); SUB(20); NEXT; // A1
+ SUB(12); SUB(20); NEXT; // A1
ADD(14); ADD(23);
- SUB(13); SUB(21); NEXT; // A2
+ SUB(13); SUB(21); NEXT; // A2
ADD(15); ADD(12); ADD(20); ADD(21);
- SUB(14); SUB(22); SUB(23); NEXT; // A3
+ SUB(14); SUB(22); SUB(23); NEXT; // A3
ADD(21); ADD(21); ADD(16); ADD(13); ADD(12); ADD(20); ADD(22);
- SUB(15); SUB(23); SUB(23); NEXT; // A4
+ SUB(15); SUB(23); SUB(23); NEXT; // A4
ADD(22); ADD(22); ADD(17); ADD(14); ADD(13); ADD(21); ADD(23);
- SUB(16); NEXT; // A5
+ SUB(16); NEXT; // A5
ADD(23); ADD(23); ADD(18); ADD(15); ADD(14); ADD(22);
- SUB(17); NEXT; // A6
+ SUB(17); NEXT; // A6
ADD(19); ADD(16); ADD(15); ADD(23);
- SUB(18); NEXT; // A7
+ SUB(18); NEXT; // A7
ADD(20); ADD(17); ADD(16);
- SUB(19); NEXT; // A8
+ SUB(19); NEXT; // A8
ADD(21); ADD(18); ADD(17);
- SUB(20); NEXT; // A9
+ SUB(20); NEXT; // A9
ADD(22); ADD(19); ADD(18);
- SUB(21); NEXT; // A10
+ SUB(21); NEXT; // A10
ADD(23); ADD(20); ADD(19);
SUB(22); // A11
RESET;
+ /* Use 2^384 = P + 2^128 + 2^96 - 2^32 + 1 to modulo reduce the final carry */
ADD_LAST; NEXT; // A0
SUB_LAST; NEXT; // A1
- NEXT; // A2
+ ; NEXT; // A2
ADD_LAST; NEXT; // A3
ADD_LAST; NEXT; // A4
- NEXT; // A5
- NEXT; // A6
- NEXT; // A7
- NEXT; // A8
- NEXT; // A9
- NEXT; // A10
+ ; NEXT; // A5
+ ; NEXT; // A6
+ ; NEXT; // A7
+ ; NEXT; // A8
+ ; NEXT; // A9
+ ; NEXT; // A10
// A11
RESET;
ADD_LAST; NEXT; // A0
SUB_LAST; NEXT; // A1
- NEXT; // A2
+ ; NEXT; // A2
ADD_LAST; NEXT; // A3
ADD_LAST; NEXT; // A4
- NEXT; // A5
- NEXT; // A6
- NEXT; // A7
- NEXT; // A8
- NEXT; // A9
- NEXT; // A10
+ ; NEXT; // A5
+ ; NEXT; // A6
+ ; NEXT; // A7
+ ; NEXT; // A8
+ ; NEXT; // A9
+ ; NEXT; // A10
// A11
LAST;
diff --git a/library/ecp_invasive.h b/library/ecp_invasive.h
index 501152c..d2ac20a 100644
--- a/library/ecp_invasive.h
+++ b/library/ecp_invasive.h
@@ -165,7 +165,7 @@
/** Fast quasi-reduction modulo p384 (FIPS 186-3 D.2.4)
*
* \param[in,out] X The address of the MPI to be converted.
- * Must have exact limb size of `(766 / biL) + 1`.
+ * Must have exact limb size of `768 / biL`.
* Upon return holds the reduced value which is
* in range `0 <= X < 2 * N` (where N is the modulus).
* The bitlength of the reduced value is the same as
diff --git a/scripts/mbedtls_dev/ecp.py b/scripts/mbedtls_dev/ecp.py
index 6d3bb05..10fcc5e 100644
--- a/scripts/mbedtls_dev/ecp.py
+++ b/scripts/mbedtls_dev/ecp.py
@@ -144,12 +144,13 @@
def is_valid(self) -> bool:
return True
-class EcpPp384R1Raw(bignum_common.ModOperationCommon,
- EcpTarget):
+
+class EcpP384R1Raw(bignum_common.ModOperationCommon,
+ EcpTarget):
"""Test cases for ecp quasi_reduction modulo p384."""
test_function = "ecp_mod_p384_raw"
test_name = "ecp_mod_p384_raw"
- input_style = "arch_split"
+ input_style = "fixed"
arity = 1
moduli = [("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
@@ -164,7 +165,7 @@
"fffffff0000000000000000fffffffe"),
# Maximum canonical P384 multiplication result
- ("0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+ ("ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
"fdfffffffe0000000000000001fffffffc0000000000000000000000000000000"
"10000000200000000fffffffe000000020000000400000000fffffffc00000004"),
@@ -178,6 +179,16 @@
"b68abef41dbd35183a0614fb7222606ffffffff84396eee542f18a9189d94396c"
"784059c17a9f18f807214ef32f2f10ffffffff8a77fac20000000000000000"),
+ # Testing with overflow in A(23) + A(20) + A(19) - A(22);
+ ("783753f8a5afba6c1862eead1deb2fcdd907272be3ffd18542b24a71ee8b26ca"
+ "b0aa33513610ff973042bbe1637cc9fc99ad36c7f703514572cf4f5c3044469a"
+ "8f5be6312c19e5d3f8fc1ac6ffffffffffffffff8c86252400000000ffffffff"),
+
+ # Testing with underflow in A(23) + A(20) + A(19) - A(22);
+ ("65e1d2362fce922663b7fd517586e88842a9b4bd092e93e6251c9c69f278cbf8"
+ "285d99ae3b53da5ba36e56701e2b17c225f1239556c5f00117fa140218b46ebd8"
+ "e34f50d0018701fa8a0a5cc00000000000000004410bcb4ffffffff00000000"),
+
# First 8 number generated by random.getrandbits(768) - seed(2,2)
("ffed9235288bc781ae66267594c9c9500925e4749b575bd13653f8dd9b1f282e"
"4067c3584ee207f8da94e3e8ab73738fcf1822ffbc6887782b491044d5e34124"
@@ -213,9 +224,7 @@
@property
def arg_a(self) -> str:
- hex_digits = bignum_common.hex_digits_for_limb((766 // self.bits_in_limb) + 1,
- self.bits_in_limb)
- return super().format_arg('{:x}'.format(self.int_a)).zfill(hex_digits)
+ 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
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 440a1e3..78aca8a 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1452,7 +1452,7 @@
size_t limbs = limbs_N;
size_t bytes = limbs * sizeof(mbedtls_mpi_uint);
- TEST_EQUAL(limbs_X, (766 / biL) + 1);
+ TEST_EQUAL(limbs_X, 2 * limbs);
TEST_EQUAL(limbs_res, limbs);
TEST_EQUAL(mbedtls_mpi_mod_modulus_setup(