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Merge pull request #1179 from Ryan-Everett-arm/key-derivation-buffer-protection-backport

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[Backport] Add buffer copying to the Key Derivation API
This commit is contained in:
David Horstmann
2024-02-15 11:54:28 +00:00
committed by GitHub
parent a2fd778868 d0d12fb42f
commit a9cc4cd1cb
3 changed files with 50 additions and 14 deletions
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49
library/psa_crypto.c
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@ -4413,10 +4413,12 @@ static psa_status_t psa_key_derivation_tls12_prf_read(
psa_status_t psa_key_derivation_output_bytes(
psa_key_derivation_operation_t *operation,
uint8_t *output,
uint8_t *output_external,
size_t output_length)
{
psa_status_t status;
LOCAL_OUTPUT_DECLARE(output_external, output);
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg(operation);
if (operation->alg == 0) {
@ -4424,13 +4426,6 @@ psa_status_t psa_key_derivation_output_bytes(
return PSA_ERROR_BAD_STATE;
}
if (output_length > operation->capacity) {
operation->capacity = 0;
/* Go through the error path to wipe all confidential data now
* that the operation object is useless. */
status = PSA_ERROR_INSUFFICIENT_DATA;
goto exit;
}
if (output_length == 0 && operation->capacity == 0) {
/* Edge case: this is a finished operation, and 0 bytes
* were requested. The right error in this case could
@ -4440,6 +4435,15 @@ psa_status_t psa_key_derivation_output_bytes(
* output_length > 0. */
return PSA_ERROR_INSUFFICIENT_DATA;
}
LOCAL_OUTPUT_ALLOC(output_external, output_length, output);
if (output_length > operation->capacity) {
operation->capacity = 0;
/* Go through the error path to wipe all confidential data now
* that the operation object is useless. */
status = PSA_ERROR_INSUFFICIENT_DATA;
goto exit;
}
operation->capacity -= output_length;
#if defined(MBEDTLS_PSA_BUILTIN_ALG_HKDF)
@ -4461,7 +4465,10 @@ psa_status_t psa_key_derivation_output_bytes(
* MBEDTLS_PSA_BUILTIN_ALG_TLS12_PSK_TO_MS */
{
(void) kdf_alg;
return PSA_ERROR_BAD_STATE;
status = PSA_ERROR_BAD_STATE;
LOCAL_OUTPUT_FREE(output_external, output);
return status;
}
exit:
@ -4473,8 +4480,12 @@ exit:
psa_algorithm_t alg = operation->alg;
psa_key_derivation_abort(operation);
operation->alg = alg;
memset(output, '!', output_length);
if (output != NULL) {
memset(output, '!', output_length);
}
}
LOCAL_OUTPUT_FREE(output_external, output);
return status;
}
@ -5025,12 +5036,22 @@ exit:
psa_status_t psa_key_derivation_input_bytes(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
const uint8_t *data,
const uint8_t *data_external,
size_t data_length)
{
return psa_key_derivation_input_internal(operation, step,
PSA_KEY_TYPE_NONE,
data, data_length);
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
LOCAL_INPUT_DECLARE(data_external, data);
LOCAL_INPUT_ALLOC(data_external, data_length, data);
status = psa_key_derivation_input_internal(operation, step,
PSA_KEY_TYPE_NONE,
data, data_length);
#if defined(MBEDTLS_PSA_COPY_CALLER_BUFFERS)
exit:
#endif
LOCAL_INPUT_FREE(data_external, data);
return status;
}
psa_status_t psa_key_derivation_input_key(