Unit tests for mbedtls_psa_ecp_generate_key()

Run the function on a few different curves with shorter, just-right and
larger buffer sizes. Perform some basic sanity checks on the output (which
is random).

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2024-10-29 20:55:11 +01:00
parent 0b7faf9011
commit 77587ce12d
3 changed files with 200 additions and 0 deletions

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@ -409,6 +409,8 @@ class DriverVSReference_ecp_light_only(outcome_analysis.DriverVSReference):
IGNORED_SUITES = [
# Modules replaced by drivers
'ecdsa', 'ecdh', 'ecjpake',
# Unit tests for the built-in implementation
'psa_crypto_ecp',
]
IGNORED_TESTS = {
'test_suite_config': [
@ -449,6 +451,8 @@ class DriverVSReference_no_ecp_at_all(outcome_analysis.DriverVSReference):
IGNORED_SUITES = [
# Modules replaced by drivers
'ecp', 'ecdsa', 'ecdh', 'ecjpake',
# Unit tests for the built-in implementation
'psa_crypto_ecp',
]
IGNORED_TESTS = {
'test_suite_config': [
@ -489,6 +493,8 @@ class DriverVSReference_ecc_no_bignum(outcome_analysis.DriverVSReference):
'ecp', 'ecdsa', 'ecdh', 'ecjpake',
'bignum_core', 'bignum_random', 'bignum_mod', 'bignum_mod_raw',
'bignum.generated', 'bignum.misc',
# Unit tests for the built-in implementation
'psa_crypto_ecp',
]
IGNORED_TESTS = {
'test_suite_config': [
@ -534,6 +540,8 @@ class DriverVSReference_ecc_ffdh_no_bignum(outcome_analysis.DriverVSReference):
'ecp', 'ecdsa', 'ecdh', 'ecjpake', 'dhm',
'bignum_core', 'bignum_random', 'bignum_mod', 'bignum_mod_raw',
'bignum.generated', 'bignum.misc',
# Unit tests for the built-in implementation
'psa_crypto_ecp',
]
IGNORED_TESTS = {
'ssl-opt': [
@ -604,6 +612,8 @@ class DriverVSReference_tfm_config(outcome_analysis.DriverVSReference):
'ecp', 'ecdsa', 'ecdh', 'ecjpake',
'bignum_core', 'bignum_random', 'bignum_mod', 'bignum_mod_raw',
'bignum.generated', 'bignum.misc',
# Unit tests for the built-in implementation
'psa_crypto_ecp',
]
IGNORED_TESTS = {
'test_suite_config': [

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@ -0,0 +1,82 @@
ECC generate: unknown family (0)
generate_key:0:256:64:PSA_ERROR_NOT_SUPPORTED
ECC generate: unknown family (0xff)
generate_key:0xff:256:64:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_R1 bad bit-size (0)
generate_key:PSA_ECC_FAMILY_SECP_R1:0:64:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_R1 bad bit-size (512)
generate_key:PSA_ECC_FAMILY_SECP_R1:512:64:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_R1 bad bit-size (528)
generate_key:PSA_ECC_FAMILY_SECP_R1:528:64:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_R1 256-bit not supported
depends_on:!MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_256
generate_key:PSA_ECC_FAMILY_SECP_R1:256:32:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_R1 384-bit not supported
depends_on:!MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_384
generate_key:PSA_ECC_FAMILY_SECP_R1:384:48:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_R1 521-bit not supported
depends_on:!MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_521
generate_key:PSA_ECC_FAMILY_SECP_R1:521:66:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_K1 256-bit not supported
depends_on:!MBEDTLS_PSA_BUILTIN_ECC_SECP_K1_256
generate_key:PSA_ECC_FAMILY_SECP_K1:256:32:PSA_ERROR_NOT_SUPPORTED
ECC generate: Curve25519 not supported
depends_on:!MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_255
generate_key:PSA_ECC_FAMILY_MONTGOMERY:255:32:PSA_ERROR_NOT_SUPPORTED
ECC generate: Curve448 not supported
depends_on:!MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_448
generate_key:PSA_ECC_FAMILY_MONTGOMERY:448:56:PSA_ERROR_NOT_SUPPORTED
ECC generate: SECP_R1 256-bit, size=31, too small
depends_on:MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_256
generate_key:PSA_ECC_FAMILY_SECP_R1:256:31:PSA_ERROR_BUFFER_TOO_SMALL
ECC generate: SECP_R1 256-bit, size=32, ok
depends_on:MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_256
generate_key:PSA_ECC_FAMILY_SECP_R1:256:32:PSA_SUCCESS
ECC generate: SECP_R1 256-bit, size=33, ok
depends_on:MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_256
generate_key:PSA_ECC_FAMILY_SECP_R1:256:33:PSA_SUCCESS
ECC generate: SECP_R1 521-bit, size=65, too small
depends_on:MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_521
generate_key:PSA_ECC_FAMILY_SECP_R1:521:65:PSA_ERROR_BUFFER_TOO_SMALL
ECC generate: SECP_R1 521-bit, size=66, ok
depends_on:MBEDTLS_PSA_BUILTIN_ECC_SECP_R1_521
generate_key:PSA_ECC_FAMILY_SECP_R1:521:66:PSA_SUCCESS
ECC generate: Curve25519, size=31, too small
depends_on:MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_255
generate_key:PSA_ECC_FAMILY_MONTGOMERY:255:31:PSA_ERROR_BUFFER_TOO_SMALL
ECC generate: Curve25519, size=32, ok
depends_on:MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_255
generate_key:PSA_ECC_FAMILY_MONTGOMERY:255:32:PSA_SUCCESS
ECC generate: Curve25519, size=33, ok
depends_on:MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_255
generate_key:PSA_ECC_FAMILY_MONTGOMERY:255:33:PSA_SUCCESS
ECC generate: Curve448, size=55, too small
depends_on:MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_448
generate_key:PSA_ECC_FAMILY_MONTGOMERY:448:55:PSA_ERROR_BUFFER_TOO_SMALL
ECC generate: Curve448, size=56, ok
depends_on:MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_448
generate_key:PSA_ECC_FAMILY_MONTGOMERY:448:56:PSA_SUCCESS
ECC generate: Curve448, size=57, ok
depends_on:MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_448
generate_key:PSA_ECC_FAMILY_MONTGOMERY:448:57:PSA_SUCCESS

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@ -0,0 +1,108 @@
/* BEGIN_HEADER */
/* Unit tests for internal functions for built-in ECC mechanisms. */
#include <psa/crypto.h>
#include "psa_crypto_ecp.h"
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_GENERATE)
/*
* Check if a buffer is all-0 bytes:
* return 1 if it is,
* 0 if it isn't.
*
* TODO: we use this in multiple test suites. Move it to tests/src.
*/
static int buffer_is_all_zero(const uint8_t *buf, size_t size)
{
for (size_t i = 0; i < size; i++) {
if (buf[i] != 0) {
return 0;
}
}
return 1;
}
/* Do some sanity checks on an ECC private key. This is not intended to be
* a full validity check, just to catch some potential mistakes. */
static int check_ecc_private_key(psa_ecc_family_t family, size_t bits,
const uint8_t *key, size_t key_length)
{
int ok = 0;
/* Check the expected length (same calculation for all curves). */
TEST_EQUAL(PSA_BITS_TO_BYTES(bits), key_length);
/* All-bits zero is invalid and means no key material was copied to the
* output buffer, or a grave RNG pluming failure. */
TEST_ASSERT(!buffer_is_all_zero(key, key_length));
/* Check the top byte of the value for non-byte-aligned curve sizes.
* This is a partial endianness check. */
if (bits % 8 != 0) {
/* All supported non-byte-aligned curve sizes are for Weierstrass
* curves with a big-endian representation. */
uint8_t top_byte = key[0];
uint8_t mask = 0xff << (bits & 8);
TEST_EQUAL(top_byte & mask, 0);
}
/* Check masked bits on Curve25519 and Curve448. */
#if defined(MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_255)
if (family == PSA_ECC_FAMILY_MONTGOMERY && bits == 255) {
TEST_EQUAL(key[0] & 0xf8, key[0]);
TEST_EQUAL(key[31] & 0xc0, 0x40);
}
#endif /* MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_255 */
#if defined(MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_448)
if (family == PSA_ECC_FAMILY_MONTGOMERY && bits == 448) {
TEST_EQUAL(key[0] & 0xfc, key[0]);
TEST_EQUAL(key[55] & 0x80, 0x80);
}
#endif /* MBEDTLS_PSA_BUILTIN_ECC_MONTGOMERY_448 */
(void) family; // unused in Weierstrass-only builds
ok = 1;
exit:
return ok;
}
#endif
/* END_HEADER */
/* BEGIN_DEPENDENCIES
* depends_on:MBEDTLS_PSA_CRYPTO_C:MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY
* END_DEPENDENCIES
*/
/* BEGIN_CASE depends_on:MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_GENERATE */
void generate_key(int family_arg, int bits_arg,
int output_size_arg,
psa_status_t expected_status)
{
psa_ecc_family_t family = family_arg;
size_t bits = bits_arg;
size_t output_size = output_size_arg;
uint8_t *output = NULL;
size_t output_length = SIZE_MAX;
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_set_key_type(&attributes, PSA_KEY_TYPE_ECC_KEY_PAIR(family));
psa_set_key_bits(&attributes, bits);
PSA_INIT();
TEST_CALLOC(output, output_size);
TEST_EQUAL(mbedtls_psa_ecp_generate_key(&attributes,
output, output_size,
&output_length),
expected_status);
if (expected_status == PSA_SUCCESS) {
TEST_LE_U(output_length, output_size);
TEST_ASSERT(check_ecc_private_key(family, bits,
output, output_length));
}
exit:
PSA_DONE();
mbedtls_free(output);
}
/* END_CASE */