gbe_fork/mbedtls/psa_crypto_ecp.c
2023-12-24 14:33:40 +02:00

562 lines
19 KiB
C

/*
* PSA ECP layer on top of Mbed TLS crypto
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
*/
#include "common.h"
#if defined(MBEDTLS_PSA_CRYPTO_C)
#include <psa/crypto.h>
#include "psa_crypto_core.h"
#include "psa_crypto_ecp.h"
#include "psa_crypto_random_impl.h"
#include "md_psa.h"
#include <stdlib.h>
#include <string.h>
#include "mbedtls/platform.h"
#include <mbedtls/ecdsa.h>
#include <mbedtls/ecdh.h>
#include <mbedtls/ecp.h>
#include <mbedtls/error.h>
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_BASIC) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_IMPORT) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_EXPORT) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
psa_status_t mbedtls_psa_ecp_load_representation(
psa_key_type_t type, size_t curve_bits,
const uint8_t *data, size_t data_length,
mbedtls_ecp_keypair **p_ecp)
{
mbedtls_ecp_group_id grp_id = MBEDTLS_ECP_DP_NONE;
psa_status_t status;
mbedtls_ecp_keypair *ecp = NULL;
size_t curve_bytes = data_length;
int explicit_bits = (curve_bits != 0);
if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type) &&
PSA_KEY_TYPE_ECC_GET_FAMILY(type) != PSA_ECC_FAMILY_MONTGOMERY) {
/* A Weierstrass public key is represented as:
* - The byte 0x04;
* - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
* - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
* So its data length is 2m+1 where m is the curve size in bits.
*/
if ((data_length & 1) == 0) {
return PSA_ERROR_INVALID_ARGUMENT;
}
curve_bytes = data_length / 2;
/* Montgomery public keys are represented in compressed format, meaning
* their curve_bytes is equal to the amount of input. */
/* Private keys are represented in uncompressed private random integer
* format, meaning their curve_bytes is equal to the amount of input. */
}
if (explicit_bits) {
/* With an explicit bit-size, the data must have the matching length. */
if (curve_bytes != PSA_BITS_TO_BYTES(curve_bits)) {
return PSA_ERROR_INVALID_ARGUMENT;
}
} else {
/* We need to infer the bit-size from the data. Since the only
* information we have is the length in bytes, the value of curve_bits
* at this stage is rounded up to the nearest multiple of 8. */
curve_bits = PSA_BYTES_TO_BITS(curve_bytes);
}
/* Allocate and initialize a key representation. */
ecp = mbedtls_calloc(1, sizeof(mbedtls_ecp_keypair));
if (ecp == NULL) {
return PSA_ERROR_INSUFFICIENT_MEMORY;
}
mbedtls_ecp_keypair_init(ecp);
/* Load the group. */
grp_id = mbedtls_ecc_group_of_psa(PSA_KEY_TYPE_ECC_GET_FAMILY(type),
curve_bits, !explicit_bits);
if (grp_id == MBEDTLS_ECP_DP_NONE) {
/* We can't distinguish between a nonsensical family/size combination
* (which would warrant PSA_ERROR_INVALID_ARGUMENT) and a
* well-regarded curve that Mbed TLS just doesn't know about (which
* would warrant PSA_ERROR_NOT_SUPPORTED). For uniformity with how
* curves that Mbed TLS knows about but for which support is disabled
* at build time, return NOT_SUPPORTED. */
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_ecp_group_load(&ecp->grp, grp_id));
if (status != PSA_SUCCESS) {
goto exit;
}
/* Load the key material. */
if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type)) {
/* Load the public value. */
status = mbedtls_to_psa_error(
mbedtls_ecp_point_read_binary(&ecp->grp, &ecp->Q,
data,
data_length));
if (status != PSA_SUCCESS) {
goto exit;
}
/* Check that the point is on the curve. */
status = mbedtls_to_psa_error(
mbedtls_ecp_check_pubkey(&ecp->grp, &ecp->Q));
if (status != PSA_SUCCESS) {
goto exit;
}
} else {
/* Load and validate the secret value. */
status = mbedtls_to_psa_error(
mbedtls_ecp_read_key(ecp->grp.id,
ecp,
data,
data_length));
if (status != PSA_SUCCESS) {
goto exit;
}
}
*p_ecp = ecp;
exit:
if (status != PSA_SUCCESS) {
mbedtls_ecp_keypair_free(ecp);
mbedtls_free(ecp);
}
return status;
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_BASIC) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_IMPORT) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_EXPORT) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) ||
* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH) */
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_IMPORT) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_EXPORT) || \
defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY)
psa_status_t mbedtls_psa_ecp_import_key(
const psa_key_attributes_t *attributes,
const uint8_t *data, size_t data_length,
uint8_t *key_buffer, size_t key_buffer_size,
size_t *key_buffer_length, size_t *bits)
{
psa_status_t status;
mbedtls_ecp_keypair *ecp = NULL;
/* Parse input */
status = mbedtls_psa_ecp_load_representation(attributes->core.type,
attributes->core.bits,
data,
data_length,
&ecp);
if (status != PSA_SUCCESS) {
goto exit;
}
if (PSA_KEY_TYPE_ECC_GET_FAMILY(attributes->core.type) ==
PSA_ECC_FAMILY_MONTGOMERY) {
*bits = ecp->grp.nbits + 1;
} else {
*bits = ecp->grp.nbits;
}
/* Re-export the data to PSA export format. There is currently no support
* for other input formats then the export format, so this is a 1-1
* copy operation. */
status = mbedtls_psa_ecp_export_key(attributes->core.type,
ecp,
key_buffer,
key_buffer_size,
key_buffer_length);
exit:
/* Always free the PK object (will also free contained ECP context) */
mbedtls_ecp_keypair_free(ecp);
mbedtls_free(ecp);
return status;
}
psa_status_t mbedtls_psa_ecp_export_key(psa_key_type_t type,
mbedtls_ecp_keypair *ecp,
uint8_t *data,
size_t data_size,
size_t *data_length)
{
psa_status_t status;
if (PSA_KEY_TYPE_IS_PUBLIC_KEY(type)) {
/* Check whether the public part is loaded */
if (mbedtls_ecp_is_zero(&ecp->Q)) {
/* Calculate the public key */
status = mbedtls_to_psa_error(
mbedtls_ecp_mul(&ecp->grp, &ecp->Q, &ecp->d, &ecp->grp.G,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE));
if (status != PSA_SUCCESS) {
return status;
}
}
status = mbedtls_to_psa_error(
mbedtls_ecp_point_write_binary(&ecp->grp, &ecp->Q,
MBEDTLS_ECP_PF_UNCOMPRESSED,
data_length,
data,
data_size));
if (status != PSA_SUCCESS) {
memset(data, 0, data_size);
}
return status;
} else {
if (data_size < PSA_BITS_TO_BYTES(ecp->grp.nbits)) {
return PSA_ERROR_BUFFER_TOO_SMALL;
}
status = mbedtls_to_psa_error(
mbedtls_ecp_write_key(ecp,
data,
PSA_BITS_TO_BYTES(ecp->grp.nbits)));
if (status == PSA_SUCCESS) {
*data_length = PSA_BITS_TO_BYTES(ecp->grp.nbits);
} else {
memset(data, 0, data_size);
}
return status;
}
}
psa_status_t mbedtls_psa_ecp_export_public_key(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
uint8_t *data, size_t data_size, size_t *data_length)
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
mbedtls_ecp_keypair *ecp = NULL;
status = mbedtls_psa_ecp_load_representation(
attributes->core.type, attributes->core.bits,
key_buffer, key_buffer_size, &ecp);
if (status != PSA_SUCCESS) {
return status;
}
status = mbedtls_psa_ecp_export_key(
PSA_KEY_TYPE_ECC_PUBLIC_KEY(
PSA_KEY_TYPE_ECC_GET_FAMILY(attributes->core.type)),
ecp, data, data_size, data_length);
mbedtls_ecp_keypair_free(ecp);
mbedtls_free(ecp);
return status;
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_IMPORT) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_EXPORT) ||
* defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_PUBLIC_KEY) */
#if defined(MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_GENERATE)
psa_status_t mbedtls_psa_ecp_generate_key(
const psa_key_attributes_t *attributes,
uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length)
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY(
attributes->core.type);
mbedtls_ecp_group_id grp_id =
mbedtls_ecc_group_of_psa(curve, attributes->core.bits, 0);
const mbedtls_ecp_curve_info *curve_info =
mbedtls_ecp_curve_info_from_grp_id(grp_id);
mbedtls_ecp_keypair ecp;
if (attributes->domain_parameters_size != 0) {
return PSA_ERROR_NOT_SUPPORTED;
}
if (grp_id == MBEDTLS_ECP_DP_NONE || curve_info == NULL) {
return PSA_ERROR_NOT_SUPPORTED;
}
mbedtls_ecp_keypair_init(&ecp);
ret = mbedtls_ecp_gen_key(grp_id, &ecp,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE);
if (ret != 0) {
mbedtls_ecp_keypair_free(&ecp);
return mbedtls_to_psa_error(ret);
}
status = mbedtls_to_psa_error(
mbedtls_ecp_write_key(&ecp, key_buffer, key_buffer_size));
mbedtls_ecp_keypair_free(&ecp);
if (status == PSA_SUCCESS) {
*key_buffer_length = key_buffer_size;
}
return status;
}
#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_GENERATE */
/****************************************************************/
/* ECDSA sign/verify */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
psa_status_t mbedtls_psa_ecdsa_sign_hash(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
uint8_t *signature, size_t signature_size, size_t *signature_length)
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
mbedtls_ecp_keypair *ecp = NULL;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t curve_bytes;
mbedtls_mpi r, s;
status = mbedtls_psa_ecp_load_representation(attributes->core.type,
attributes->core.bits,
key_buffer,
key_buffer_size,
&ecp);
if (status != PSA_SUCCESS) {
return status;
}
curve_bytes = PSA_BITS_TO_BYTES(ecp->grp.pbits);
mbedtls_mpi_init(&r);
mbedtls_mpi_init(&s);
if (signature_size < 2 * curve_bytes) {
ret = MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL;
goto cleanup;
}
if (PSA_ALG_ECDSA_IS_DETERMINISTIC(alg)) {
#if defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH(alg);
mbedtls_md_type_t md_alg = mbedtls_md_type_from_psa_alg(hash_alg);
MBEDTLS_MPI_CHK(mbedtls_ecdsa_sign_det_ext(
&ecp->grp, &r, &s,
&ecp->d, hash,
hash_length, md_alg,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE));
#else
ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE;
goto cleanup;
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
} else {
(void) alg;
MBEDTLS_MPI_CHK(mbedtls_ecdsa_sign(&ecp->grp, &r, &s, &ecp->d,
hash, hash_length,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE));
}
MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&r,
signature,
curve_bytes));
MBEDTLS_MPI_CHK(mbedtls_mpi_write_binary(&s,
signature + curve_bytes,
curve_bytes));
cleanup:
mbedtls_mpi_free(&r);
mbedtls_mpi_free(&s);
if (ret == 0) {
*signature_length = 2 * curve_bytes;
}
mbedtls_ecp_keypair_free(ecp);
mbedtls_free(ecp);
return mbedtls_to_psa_error(ret);
}
psa_status_t mbedtls_psa_ecp_load_public_part(mbedtls_ecp_keypair *ecp)
{
int ret = 0;
/* Check whether the public part is loaded. If not, load it. */
if (mbedtls_ecp_is_zero(&ecp->Q)) {
ret = mbedtls_ecp_mul(&ecp->grp, &ecp->Q,
&ecp->d, &ecp->grp.G,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE);
}
return mbedtls_to_psa_error(ret);
}
psa_status_t mbedtls_psa_ecdsa_verify_hash(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
psa_algorithm_t alg, const uint8_t *hash, size_t hash_length,
const uint8_t *signature, size_t signature_length)
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
mbedtls_ecp_keypair *ecp = NULL;
size_t curve_bytes;
mbedtls_mpi r, s;
(void) alg;
status = mbedtls_psa_ecp_load_representation(attributes->core.type,
attributes->core.bits,
key_buffer,
key_buffer_size,
&ecp);
if (status != PSA_SUCCESS) {
return status;
}
curve_bytes = PSA_BITS_TO_BYTES(ecp->grp.pbits);
mbedtls_mpi_init(&r);
mbedtls_mpi_init(&s);
if (signature_length != 2 * curve_bytes) {
status = PSA_ERROR_INVALID_SIGNATURE;
goto cleanup;
}
status = mbedtls_to_psa_error(mbedtls_mpi_read_binary(&r,
signature,
curve_bytes));
if (status != PSA_SUCCESS) {
goto cleanup;
}
status = mbedtls_to_psa_error(mbedtls_mpi_read_binary(&s,
signature + curve_bytes,
curve_bytes));
if (status != PSA_SUCCESS) {
goto cleanup;
}
status = mbedtls_psa_ecp_load_public_part(ecp);
if (status != PSA_SUCCESS) {
goto cleanup;
}
status = mbedtls_to_psa_error(mbedtls_ecdsa_verify(&ecp->grp, hash,
hash_length, &ecp->Q,
&r, &s));
cleanup:
mbedtls_mpi_free(&r);
mbedtls_mpi_free(&s);
mbedtls_ecp_keypair_free(ecp);
mbedtls_free(ecp);
return status;
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || \
* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
/****************************************************************/
/* ECDH Key Agreement */
/****************************************************************/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDH)
psa_status_t mbedtls_psa_key_agreement_ecdh(
const psa_key_attributes_t *attributes,
const uint8_t *key_buffer, size_t key_buffer_size,
psa_algorithm_t alg, const uint8_t *peer_key, size_t peer_key_length,
uint8_t *shared_secret, size_t shared_secret_size,
size_t *shared_secret_length)
{
psa_status_t status;
if (!PSA_KEY_TYPE_IS_ECC_KEY_PAIR(attributes->core.type) ||
!PSA_ALG_IS_ECDH(alg)) {
return PSA_ERROR_INVALID_ARGUMENT;
}
mbedtls_ecp_keypair *ecp = NULL;
status = mbedtls_psa_ecp_load_representation(
attributes->core.type,
attributes->core.bits,
key_buffer,
key_buffer_size,
&ecp);
if (status != PSA_SUCCESS) {
return status;
}
mbedtls_ecp_keypair *their_key = NULL;
mbedtls_ecdh_context ecdh;
size_t bits = 0;
psa_ecc_family_t curve = mbedtls_ecc_group_to_psa(ecp->grp.id, &bits);
mbedtls_ecdh_init(&ecdh);
status = mbedtls_psa_ecp_load_representation(
PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve),
bits,
peer_key,
peer_key_length,
&their_key);
if (status != PSA_SUCCESS) {
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params(&ecdh, their_key, MBEDTLS_ECDH_THEIRS));
if (status != PSA_SUCCESS) {
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params(&ecdh, ecp, MBEDTLS_ECDH_OURS));
if (status != PSA_SUCCESS) {
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_ecdh_calc_secret(&ecdh,
shared_secret_length,
shared_secret, shared_secret_size,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE));
if (status != PSA_SUCCESS) {
goto exit;
}
if (PSA_BITS_TO_BYTES(bits) != *shared_secret_length) {
status = PSA_ERROR_CORRUPTION_DETECTED;
}
exit:
if (status != PSA_SUCCESS) {
mbedtls_platform_zeroize(shared_secret, shared_secret_size);
}
mbedtls_ecdh_free(&ecdh);
mbedtls_ecp_keypair_free(their_key);
mbedtls_free(their_key);
mbedtls_ecp_keypair_free(ecp);
mbedtls_free(ecp);
return status;
}
#endif /* MBEDTLS_PSA_BUILTIN_ALG_ECDH */
#endif /* MBEDTLS_PSA_CRYPTO_C */