mbedtls/library/psa_crypto_pake.c
Przemek Stekiel 2797d37424 Split handling of memory allocation for password between core and driver
Driver is now responsible for creating its own copy of the password in the setup function.
After calling pake setup driver entry point core frees memory for password.

Signed-off-by: Przemek Stekiel <przemyslaw.stekiel@mobica.com>
2023-02-22 11:30:31 +01:00

593 lines
22 KiB
C

/*
* PSA PAKE layer on top of Mbed TLS software crypto
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_PSA_CRYPTO_C)
#include <psa/crypto.h>
#include "psa_crypto_core.h"
#include "psa_crypto_pake.h"
#include "psa_crypto_slot_management.h"
#include <mbedtls/ecjpake.h>
#include <mbedtls/psa_util.h>
#include <mbedtls/platform.h>
#include <mbedtls/error.h>
#include <string.h>
/*
* State sequence:
*
* psa_pake_setup()
* |
* |-- In any order:
* | | psa_pake_set_password_key()
* | | psa_pake_set_user()
* | | psa_pake_set_peer()
* | | psa_pake_set_role()
* |
* |--- In any order: (First round input before or after first round output)
* | |
* | |------ In Order
* | | | psa_pake_output(PSA_PAKE_STEP_KEY_SHARE)
* | | | psa_pake_output(PSA_PAKE_STEP_ZK_PUBLIC)
* | | | psa_pake_output(PSA_PAKE_STEP_ZK_PROOF)
* | | | psa_pake_output(PSA_PAKE_STEP_KEY_SHARE)
* | | | psa_pake_output(PSA_PAKE_STEP_ZK_PUBLIC)
* | | | psa_pake_output(PSA_PAKE_STEP_ZK_PROOF)
* | |
* | |------ In Order:
* | | psa_pake_input(PSA_PAKE_STEP_KEY_SHARE)
* | | psa_pake_input(PSA_PAKE_STEP_ZK_PUBLIC)
* | | psa_pake_input(PSA_PAKE_STEP_ZK_PROOF)
* | | psa_pake_input(PSA_PAKE_STEP_KEY_SHARE)
* | | psa_pake_input(PSA_PAKE_STEP_ZK_PUBLIC)
* | | psa_pake_input(PSA_PAKE_STEP_ZK_PROOF)
* |
* |--- In any order: (Second round input before or after second round output)
* | |
* | |------ In Order
* | | | psa_pake_output(PSA_PAKE_STEP_KEY_SHARE)
* | | | psa_pake_output(PSA_PAKE_STEP_ZK_PUBLIC)
* | | | psa_pake_output(PSA_PAKE_STEP_ZK_PROOF)
* | |
* | |------ In Order:
* | | psa_pake_input(PSA_PAKE_STEP_KEY_SHARE)
* | | psa_pake_input(PSA_PAKE_STEP_ZK_PUBLIC)
* | | psa_pake_input(PSA_PAKE_STEP_ZK_PROOF)
* |
* psa_pake_get_implicit_key()
* psa_pake_abort()
*/
/*
* The first PAKE step shares the same sequences of the second PAKE step
* but with a second set of KEY_SHARE/ZK_PUBLIC/ZK_PROOF outputs/inputs.
* It's simpler to share the same sequences numbers of the first
* set of KEY_SHARE/ZK_PUBLIC/ZK_PROOF outputs/inputs in both PAKE steps.
*
* State sequence with step, state & sequence enums:
* => Input & Output Step = PSA_PAKE_STEP_INVALID
* => state = PSA_PAKE_STATE_INVALID
* psa_pake_setup()
* => Input & Output Step = PSA_PAKE_STEP_X1_X2
* => state = PSA_PAKE_STATE_SETUP
* => sequence = PSA_PAKE_SEQ_INVALID
* |
* |--- In any order: (First round input before or after first round output)
* | | First call of psa_pake_output() or psa_pake_input() sets
* | | state = PSA_PAKE_STATE_READY
* | |
* | |------ In Order: => state = PSA_PAKE_OUTPUT_X1_X2
* | | | psa_pake_output() => sequence = PSA_PAKE_X1_STEP_KEY_SHARE
* | | | psa_pake_output() => sequence = PSA_PAKE_X1_STEP_ZK_PUBLIC
* | | | psa_pake_output() => sequence = PSA_PAKE_X1_STEP_ZK_PROOF
* | | | psa_pake_output() => sequence = PSA_PAKE_X2_STEP_KEY_SHARE
* | | | psa_pake_output() => sequence = PSA_PAKE_X2_STEP_ZK_PUBLIC
* | | | psa_pake_output() => sequence = PSA_PAKE_X2_STEP_ZK_PROOF
* | | | => state = PSA_PAKE_STATE_READY
* | | | => sequence = PSA_PAKE_SEQ_INVALID
* | | | => Output Step = PSA_PAKE_STEP_X2S
* | |
* | |------ In Order: => state = PSA_PAKE_INPUT_X1_X2
* | | | psa_pake_input() => sequence = PSA_PAKE_X1_STEP_KEY_SHARE
* | | | psa_pake_input() => sequence = PSA_PAKE_X1_STEP_ZK_PUBLIC
* | | | psa_pake_input() => sequence = PSA_PAKE_X1_STEP_ZK_PROOF
* | | | psa_pake_input() => sequence = PSA_PAKE_X2_STEP_KEY_SHARE
* | | | psa_pake_input() => sequence = PSA_PAKE_X2_STEP_ZK_PUBLIC
* | | | psa_pake_input() => sequence = PSA_PAKE_X2_STEP_ZK_PROOF
* | | | => state = PSA_PAKE_STATE_READY
* | | | => sequence = PSA_PAKE_SEQ_INVALID
* | | | => Output Step = PSA_PAKE_INPUT_X4S
* |
* |--- In any order: (Second round input before or after second round output)
* | |
* | |------ In Order: => state = PSA_PAKE_OUTPUT_X2S
* | | | psa_pake_output() => sequence = PSA_PAKE_X1_STEP_KEY_SHARE
* | | | psa_pake_output() => sequence = PSA_PAKE_X1_STEP_ZK_PUBLIC
* | | | psa_pake_output() => sequence = PSA_PAKE_X1_STEP_ZK_PROOF
* | | | => state = PSA_PAKE_STATE_READY
* | | | => sequence = PSA_PAKE_SEQ_INVALID
* | | | => Output Step = PSA_PAKE_STEP_DERIVE
* | |
* | |------ In Order: => state = PSA_PAKE_INPUT_X4S
* | | | psa_pake_input() => sequence = PSA_PAKE_X1_STEP_KEY_SHARE
* | | | psa_pake_input() => sequence = PSA_PAKE_X1_STEP_ZK_PUBLIC
* | | | psa_pake_input() => sequence = PSA_PAKE_X1_STEP_ZK_PROOF
* | | | => state = PSA_PAKE_STATE_READY
* | | | => sequence = PSA_PAKE_SEQ_INVALID
* | | | => Output Step = PSA_PAKE_STEP_DERIVE
* |
* psa_pake_get_implicit_key()
* => Input & Output Step = PSA_PAKE_STEP_INVALID
*/
#if defined(MBEDTLS_PSA_BUILTIN_ALG_JPAKE)
static psa_status_t mbedtls_ecjpake_to_psa_error(int ret)
{
switch (ret) {
case MBEDTLS_ERR_MPI_BAD_INPUT_DATA:
case MBEDTLS_ERR_ECP_BAD_INPUT_DATA:
case MBEDTLS_ERR_ECP_INVALID_KEY:
case MBEDTLS_ERR_ECP_VERIFY_FAILED:
return PSA_ERROR_DATA_INVALID;
case MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL:
case MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL:
return PSA_ERROR_BUFFER_TOO_SMALL;
case MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE:
return PSA_ERROR_NOT_SUPPORTED;
case MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED:
return PSA_ERROR_CORRUPTION_DETECTED;
default:
return PSA_ERROR_GENERIC_ERROR;
}
}
#endif
#if defined(MBEDTLS_PSA_BUILTIN_ALG_JPAKE)
static psa_status_t psa_pake_ecjpake_setup(mbedtls_psa_pake_operation_t *operation)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_ecjpake_role role;
if (operation->role == PSA_PAKE_ROLE_CLIENT) {
role = MBEDTLS_ECJPAKE_CLIENT;
} else if (operation->role == PSA_PAKE_ROLE_SERVER) {
role = MBEDTLS_ECJPAKE_SERVER;
} else {
return PSA_ERROR_BAD_STATE;
}
if (operation->password_len == 0) {
return PSA_ERROR_BAD_STATE;
}
ret = mbedtls_ecjpake_setup(&operation->ctx.pake,
role,
MBEDTLS_MD_SHA256,
MBEDTLS_ECP_DP_SECP256R1,
operation->password,
operation->password_len);
mbedtls_platform_zeroize(operation->password, operation->password_len);
mbedtls_free(operation->password);
operation->password = NULL;
operation->password_len = 0;
if (ret != 0) {
return mbedtls_ecjpake_to_psa_error(ret);
}
return PSA_SUCCESS;
}
psa_status_t mbedtls_psa_pake_setup(mbedtls_psa_pake_operation_t *operation,
const psa_crypto_driver_pake_inputs_t *inputs)
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
uint8_t *password = inputs->password;
size_t password_len = inputs->password_len;
psa_pake_role_t role = inputs->role;
psa_pake_cipher_suite_t cipher_suite = inputs->cipher_suite;
memset(operation, 0, sizeof(mbedtls_psa_pake_operation_t));
#if defined(MBEDTLS_PSA_BUILTIN_ALG_JPAKE)
if (cipher_suite.algorithm == PSA_ALG_JPAKE) {
if (cipher_suite.type != PSA_PAKE_PRIMITIVE_TYPE_ECC ||
cipher_suite.family != PSA_ECC_FAMILY_SECP_R1 ||
cipher_suite.bits != 256 ||
cipher_suite.hash != PSA_ALG_SHA_256) {
status = PSA_ERROR_NOT_SUPPORTED;
goto error;
}
if (role != PSA_PAKE_ROLE_CLIENT &&
role != PSA_PAKE_ROLE_SERVER) {
status = PSA_ERROR_NOT_SUPPORTED;
goto error;
}
mbedtls_ecjpake_init(&operation->ctx.pake);
operation->password = mbedtls_calloc(1, password_len);
if (operation->password == NULL) {
status = PSA_ERROR_INSUFFICIENT_MEMORY;
goto error;
}
memcpy(operation->password, password, password_len);
operation->password_len = password_len;
operation->role = role;
operation->alg = cipher_suite.algorithm;
mbedtls_platform_zeroize(operation->buffer, MBEDTLS_PSA_PAKE_BUFFER_SIZE);
operation->buffer_length = 0;
operation->buffer_offset = 0;
status = psa_pake_ecjpake_setup(operation);
if (status != PSA_SUCCESS) {
goto error;
}
return PSA_SUCCESS;
} else
#else
(void) operation;
(void) inputs;
#endif
{ status = PSA_ERROR_NOT_SUPPORTED; }
error:
mbedtls_psa_pake_abort(operation);
return status;
}
static psa_status_t mbedtls_psa_pake_output_internal(
mbedtls_psa_pake_operation_t *operation,
psa_pake_step_t step,
const psa_pake_computation_stage_t *computation_stage,
uint8_t *output,
size_t output_size,
size_t *output_length)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t length;
(void) step;
if (operation->alg == PSA_ALG_NONE) {
return PSA_ERROR_BAD_STATE;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_JPAKE)
/*
* The PSA CRYPTO PAKE and MbedTLS JPAKE API have a different
* handling of output sequencing.
*
* The MbedTLS JPAKE API outputs the whole X1+X2 and X2S steps data
* at once, on the other side the PSA CRYPTO PAKE api requires
* the KEY_SHARE/ZP_PUBLIC/ZK_PROOF parts of X1, X2 & X2S to be
* retrieved in sequence.
*
* In order to achieve API compatibility, the whole X1+X2 or X2S steps
* data is stored in an intermediate buffer at first step output call,
* and data is sliced down by parsing the ECPoint records in order
* to return the right parts on each step.
*/
if (operation->alg == PSA_ALG_JPAKE) {
const psa_jpake_computation_stage_t *jpake_computation_stage =
&computation_stage->data.jpake_computation_stage;
/* Initialize & write round on KEY_SHARE sequences */
if (jpake_computation_stage->state == PSA_PAKE_OUTPUT_X1_X2 &&
jpake_computation_stage->sequence == PSA_PAKE_X1_STEP_KEY_SHARE) {
ret = mbedtls_ecjpake_write_round_one(&operation->ctx.pake,
operation->buffer,
MBEDTLS_PSA_PAKE_BUFFER_SIZE,
&operation->buffer_length,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE);
if (ret != 0) {
return mbedtls_ecjpake_to_psa_error(ret);
}
operation->buffer_offset = 0;
} else if (jpake_computation_stage->state == PSA_PAKE_OUTPUT_X2S &&
jpake_computation_stage->sequence == PSA_PAKE_X1_STEP_KEY_SHARE) {
ret = mbedtls_ecjpake_write_round_two(&operation->ctx.pake,
operation->buffer,
MBEDTLS_PSA_PAKE_BUFFER_SIZE,
&operation->buffer_length,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE);
if (ret != 0) {
return mbedtls_ecjpake_to_psa_error(ret);
}
operation->buffer_offset = 0;
}
/*
* mbedtls_ecjpake_write_round_xxx() outputs thing in the format
* defined by draft-cragie-tls-ecjpake-01 section 7. The summary is
* that the data for each step is prepended with a length byte, and
* then they're concatenated. Additionally, the server's second round
* output is prepended with a 3-bytes ECParameters structure.
*
* In PSA, we output each step separately, and don't prepend the
* output with a length byte, even less a curve identifier, as that
* information is already available.
*/
if (jpake_computation_stage->state == PSA_PAKE_OUTPUT_X2S &&
jpake_computation_stage->sequence == PSA_PAKE_X1_STEP_KEY_SHARE &&
operation->role == PSA_PAKE_ROLE_SERVER) {
/* Skip ECParameters, with is 3 bytes (RFC 8422) */
operation->buffer_offset += 3;
}
/* Read the length byte then move past it to the data */
length = operation->buffer[operation->buffer_offset];
operation->buffer_offset += 1;
if (operation->buffer_offset + length > operation->buffer_length) {
return PSA_ERROR_DATA_CORRUPT;
}
if (output_size < length) {
return PSA_ERROR_BUFFER_TOO_SMALL;
}
memcpy(output,
operation->buffer + operation->buffer_offset,
length);
*output_length = length;
operation->buffer_offset += length;
/* Reset buffer after ZK_PROOF sequence */
if ((jpake_computation_stage->state == PSA_PAKE_OUTPUT_X1_X2 &&
jpake_computation_stage->sequence == PSA_PAKE_X2_STEP_ZK_PROOF) ||
(jpake_computation_stage->state == PSA_PAKE_OUTPUT_X2S &&
jpake_computation_stage->sequence == PSA_PAKE_X1_STEP_ZK_PROOF)) {
mbedtls_platform_zeroize(operation->buffer, MBEDTLS_PSA_PAKE_BUFFER_SIZE);
operation->buffer_length = 0;
operation->buffer_offset = 0;
}
return PSA_SUCCESS;
} else
#else
(void) step;
(void) computation_stage;
(void) output;
(void) output_size;
(void) output_length;
#endif
{ return PSA_ERROR_NOT_SUPPORTED; }
}
psa_status_t mbedtls_psa_pake_output(mbedtls_psa_pake_operation_t *operation,
psa_pake_step_t step,
const psa_pake_computation_stage_t *computation_stage,
uint8_t *output,
size_t output_size,
size_t *output_length)
{
psa_status_t status = mbedtls_psa_pake_output_internal(
operation, step, computation_stage, output, output_size, output_length);
if (status != PSA_SUCCESS) {
mbedtls_psa_pake_abort(operation);
}
return status;
}
static psa_status_t mbedtls_psa_pake_input_internal(
mbedtls_psa_pake_operation_t *operation,
psa_pake_step_t step,
const psa_pake_computation_stage_t *computation_stage,
const uint8_t *input,
size_t input_length)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
(void) step;
if (operation->alg == PSA_ALG_NONE) {
return PSA_ERROR_BAD_STATE;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_JPAKE)
/*
* The PSA CRYPTO PAKE and MbedTLS JPAKE API have a different
* handling of input sequencing.
*
* The MbedTLS JPAKE API takes the whole X1+X2 or X4S steps data
* at once as input, on the other side the PSA CRYPTO PAKE api requires
* the KEY_SHARE/ZP_PUBLIC/ZK_PROOF parts of X1, X2 & X4S to be
* given in sequence.
*
* In order to achieve API compatibility, each X1+X2 or X4S step data
* is stored sequentially in an intermediate buffer and given to the
* MbedTLS JPAKE API on the last step.
*
* This causes any input error to be only detected on the last step.
*/
if (operation->alg == PSA_ALG_JPAKE) {
const psa_jpake_computation_stage_t *jpake_computation_stage =
&computation_stage->data.jpake_computation_stage;
/*
* Copy input to local buffer and format it as the Mbed TLS API
* expects, i.e. as defined by draft-cragie-tls-ecjpake-01 section 7.
* The summary is that the data for each step is prepended with a
* length byte, and then they're concatenated. Additionally, the
* server's second round output is prepended with a 3-bytes
* ECParameters structure - which means we have to prepend that when
* we're a client.
*/
if (jpake_computation_stage->state == PSA_PAKE_INPUT_X4S &&
jpake_computation_stage->sequence == PSA_PAKE_X1_STEP_KEY_SHARE &&
operation->role == PSA_PAKE_ROLE_CLIENT) {
/* We only support secp256r1. */
/* This is the ECParameters structure defined by RFC 8422. */
unsigned char ecparameters[3] = {
3, /* named_curve */
0, 23 /* secp256r1 */
};
memcpy(operation->buffer + operation->buffer_length,
ecparameters, sizeof(ecparameters));
operation->buffer_length += sizeof(ecparameters);
}
/* Write the length byte */
operation->buffer[operation->buffer_length] = (uint8_t) input_length;
operation->buffer_length += 1;
/* Finally copy the data */
memcpy(operation->buffer + operation->buffer_length,
input, input_length);
operation->buffer_length += input_length;
/* Load buffer at each last round ZK_PROOF */
if (jpake_computation_stage->state == PSA_PAKE_INPUT_X1_X2 &&
jpake_computation_stage->sequence == PSA_PAKE_X2_STEP_ZK_PROOF) {
ret = mbedtls_ecjpake_read_round_one(&operation->ctx.pake,
operation->buffer,
operation->buffer_length);
mbedtls_platform_zeroize(operation->buffer, MBEDTLS_PSA_PAKE_BUFFER_SIZE);
operation->buffer_length = 0;
if (ret != 0) {
return mbedtls_ecjpake_to_psa_error(ret);
}
} else if (jpake_computation_stage->state == PSA_PAKE_INPUT_X4S &&
jpake_computation_stage->sequence == PSA_PAKE_X1_STEP_ZK_PROOF) {
ret = mbedtls_ecjpake_read_round_two(&operation->ctx.pake,
operation->buffer,
operation->buffer_length);
mbedtls_platform_zeroize(operation->buffer, MBEDTLS_PSA_PAKE_BUFFER_SIZE);
operation->buffer_length = 0;
if (ret != 0) {
return mbedtls_ecjpake_to_psa_error(ret);
}
}
return PSA_SUCCESS;
} else
#else
(void) step;
(void) computation_stage;
(void) input;
(void) input_length;
#endif
{ return PSA_ERROR_NOT_SUPPORTED; }
}
psa_status_t mbedtls_psa_pake_input(mbedtls_psa_pake_operation_t *operation,
psa_pake_step_t step,
const psa_pake_computation_stage_t *computation_stage,
const uint8_t *input,
size_t input_length)
{
psa_status_t status = mbedtls_psa_pake_input_internal(
operation, step, computation_stage, input, input_length);
if (status != PSA_SUCCESS) {
mbedtls_psa_pake_abort(operation);
}
return status;
}
psa_status_t mbedtls_psa_pake_get_implicit_key(
mbedtls_psa_pake_operation_t *operation,
uint8_t *output, size_t *output_size)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if (operation->alg == PSA_ALG_NONE) {
return PSA_ERROR_BAD_STATE;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_JPAKE)
if (operation->alg == PSA_ALG_JPAKE) {
ret = mbedtls_ecjpake_write_shared_key(&operation->ctx.pake,
operation->buffer,
MBEDTLS_PSA_PAKE_BUFFER_SIZE,
&operation->buffer_length,
mbedtls_psa_get_random,
MBEDTLS_PSA_RANDOM_STATE);
if (ret != 0) {
mbedtls_psa_pake_abort(operation);
return mbedtls_ecjpake_to_psa_error(ret);
}
memcpy(output, operation->buffer, operation->buffer_length);
*output_size = operation->buffer_length;
mbedtls_platform_zeroize(operation->buffer, MBEDTLS_PSA_PAKE_BUFFER_SIZE);
mbedtls_psa_pake_abort(operation);
return PSA_SUCCESS;
} else
#else
(void) output;
#endif
{ return PSA_ERROR_NOT_SUPPORTED; }
}
psa_status_t mbedtls_psa_pake_abort(mbedtls_psa_pake_operation_t *operation)
{
if (operation->alg == PSA_ALG_NONE) {
return PSA_SUCCESS;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_JPAKE)
if (operation->alg == PSA_ALG_JPAKE) {
if (operation->password_len > 0) {
mbedtls_platform_zeroize(operation->password, operation->password_len);
}
mbedtls_free(operation->password);
operation->password = NULL;
operation->password_len = 0;
operation->role = PSA_PAKE_ROLE_NONE;
mbedtls_platform_zeroize(operation->buffer, MBEDTLS_PSA_PAKE_BUFFER_SIZE);
operation->buffer_length = 0;
operation->buffer_offset = 0;
mbedtls_ecjpake_free(&operation->ctx.pake);
}
#endif
operation->alg = PSA_ALG_NONE;
return PSA_SUCCESS;
}
#endif /* MBEDTLS_PSA_BUILTIN_PAKE */
#endif /* MBEDTLS_PSA_CRYPTO_C */