Add buffer copying to psa_generate_random()

Signed-off-by: David Horstmann <david.horstmann@arm.com>
This commit is contained in:
David Horstmann 2024-02-06 15:27:49 +00:00
parent cf3457ef26
commit 6e99bb203f

@ -4190,6 +4190,54 @@ psa_status_t mbedtls_psa_verify_hash_abort(
* defined( MBEDTLS_ECP_RESTARTABLE ) */
}
static psa_status_t psa_generate_random_internal(uint8_t *output,
size_t output_size)
{
GUARD_MODULE_INITIALIZED;
psa_status_t status;
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
size_t output_length = 0;
status = mbedtls_psa_external_get_random(&global_data.rng,
output, output_size,
&output_length);
if (status != PSA_SUCCESS) {
goto exit;
}
/* Breaking up a request into smaller chunks is currently not supported
* for the external RNG interface. */
if (output_length != output_size) {
status = PSA_ERROR_INSUFFICIENT_ENTROPY;
goto exit;
}
status = PSA_SUCCESS;
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
while (output_size > 0) {
size_t request_size =
(output_size > MBEDTLS_PSA_RANDOM_MAX_REQUEST ?
MBEDTLS_PSA_RANDOM_MAX_REQUEST :
output_size);
int ret = mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE,
output, request_size);
if (ret != 0) {
status = mbedtls_to_psa_error(ret);
goto exit;
}
output_size -= request_size;
output += request_size;
}
status = PSA_SUCCESS;
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
exit:
return status;
}
/****************************************************************/
/* Symmetric cryptography */
/****************************************************************/
@ -4308,7 +4356,7 @@ psa_status_t psa_cipher_generate_iv(psa_cipher_operation_t *operation,
goto exit;
}
status = psa_generate_random(local_iv, default_iv_length);
status = psa_generate_random_internal(local_iv, default_iv_length);
if (status != PSA_SUCCESS) {
goto exit;
}
@ -4497,7 +4545,7 @@ psa_status_t psa_cipher_encrypt(mbedtls_svc_key_id_t key,
goto exit;
}
status = psa_generate_random(local_iv, default_iv_length);
status = psa_generate_random_internal(local_iv, default_iv_length);
if (status != PSA_SUCCESS) {
goto exit;
}
@ -5003,7 +5051,7 @@ psa_status_t psa_aead_generate_nonce(psa_aead_operation_t *operation,
goto exit;
}
status = psa_generate_random(local_nonce, required_nonce_size);
status = psa_generate_random_internal(local_nonce, required_nonce_size);
if (status != PSA_SUCCESS) {
goto exit;
}
@ -7517,7 +7565,7 @@ exit:
* some constant data such as zeros, which would result in the data
* being protected with a reproducible, easily knowable key.
*/
psa_generate_random(output, output_size);
psa_generate_random_internal(output, output_size);
*output_length = output_size;
}
@ -7527,7 +7575,6 @@ exit:
}
/****************************************************************/
/* Random generation */
/****************************************************************/
@ -7596,44 +7643,19 @@ static psa_status_t mbedtls_psa_random_seed(mbedtls_psa_random_context_t *rng)
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
}
psa_status_t psa_generate_random(uint8_t *output,
psa_status_t psa_generate_random(uint8_t *output_external,
size_t output_size)
{
GUARD_MODULE_INITIALIZED;
psa_status_t status;
#if defined(MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG)
LOCAL_OUTPUT_DECLARE(output_external, output);
LOCAL_OUTPUT_ALLOC(output_external, output_size, output);
size_t output_length = 0;
psa_status_t status = mbedtls_psa_external_get_random(&global_data.rng,
output, output_size,
&output_length);
if (status != PSA_SUCCESS) {
return status;
}
/* Breaking up a request into smaller chunks is currently not supported
* for the external RNG interface. */
if (output_length != output_size) {
return PSA_ERROR_INSUFFICIENT_ENTROPY;
}
return PSA_SUCCESS;
status = psa_generate_random_internal(output, output_size);
#else /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
while (output_size > 0) {
size_t request_size =
(output_size > MBEDTLS_PSA_RANDOM_MAX_REQUEST ?
MBEDTLS_PSA_RANDOM_MAX_REQUEST :
output_size);
int ret = mbedtls_psa_get_random(MBEDTLS_PSA_RANDOM_STATE,
output, request_size);
if (ret != 0) {
return mbedtls_to_psa_error(ret);
}
output_size -= request_size;
output += request_size;
}
return PSA_SUCCESS;
#endif /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
exit:
LOCAL_OUTPUT_FREE(output_external, output);
return status;
}
/* Wrapper function allowing the classic API to use the PSA RNG.