Key derivation: forbid output_key without input_key

If none of the inputs to a key derivation is a
PSA_KEY_DERIVATION_INPUT_SECRET passed with
psa_key_derivation_input_key(), forbid
psa_key_derivation_output_key(). It usually doesn't make sense to
derive a key object if the secret isn't itself a proper key.
This commit is contained in:
Gilles Peskine 2019-09-24 18:21:06 +02:00
parent 1a2904c49a
commit 178c9aa966
5 changed files with 53 additions and 6 deletions

View File

@ -3527,6 +3527,11 @@ psa_status_t psa_key_derivation_output_bytes(
* In all cases, the data that is read is discarded from the operation.
* The operation's capacity is decreased by the number of bytes read.
*
* For algorithms that take an input step #PSA_KEY_DERIVATION_INPUT_SECRET,
* the input to that step must be provided with psa_key_derivation_input_key().
* Future versions of this specification may include additional restrictions
* on the derived key based on the attributes and strength of the secret key.
*
* \param[in] attributes The attributes for the new key.
* \param[in,out] operation The key derivation operation object to read from.
* \param[out] handle On success, a handle to the newly created key.
@ -3549,6 +3554,9 @@ psa_status_t psa_key_derivation_output_bytes(
* implementation in general or in this particular location.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* The provided key attributes are not valid for the operation.
* \retval #PSA_ERROR_NOT_PERMITTED
* The #PSA_KEY_DERIVATION_INPUT_SECRET input was not provided through
* a key.
* \retval #PSA_ERROR_BAD_STATE
* The operation state is not valid (it must be active and completed
* all required input steps).

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@ -255,6 +255,7 @@ typedef struct psa_tls12_prf_key_derivation_s
struct psa_key_derivation_s
{
psa_algorithm_t alg;
unsigned int can_output_key : 1;
size_t capacity;
union
{
@ -268,7 +269,7 @@ struct psa_key_derivation_s
};
/* This only zeroes out the first byte in the union, the rest is unspecified. */
#define PSA_KEY_DERIVATION_OPERATION_INIT {0, 0, {0}}
#define PSA_KEY_DERIVATION_OPERATION_INIT {0, 0, 0, {0}}
static inline struct psa_key_derivation_s psa_key_derivation_operation_init( void )
{
const struct psa_key_derivation_s v = PSA_KEY_DERIVATION_OPERATION_INIT;

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@ -1622,7 +1622,11 @@
* (passed to psa_key_derivation_input_key())
* or the shared secret resulting from a key agreement
* (obtained via psa_key_derivation_key_agreement()).
* It can also be a direct input (passed to key_derivation_input_bytes()).
*
* The secret can also be a direct input (passed to
* key_derivation_input_bytes()). In this case, the derivation operation
* may not be used to derive keys: the operation will only allow
* psa_key_derivation_output_bytes(), not psa_key_derivation_output_key().
*/
#define PSA_KEY_DERIVATION_INPUT_SECRET ((psa_key_derivation_step_t)0x0101)

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@ -4787,6 +4787,9 @@ psa_status_t psa_key_derivation_output_key( const psa_key_attributes_t *attribut
if( psa_get_key_bits( attributes ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
if( ! operation->can_output_key )
return( PSA_ERROR_NOT_PERMITTED );
status = psa_start_key_creation( PSA_KEY_CREATION_DERIVE,
attributes, handle, &slot, &driver );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
@ -5174,6 +5177,7 @@ psa_status_t psa_key_derivation_input_key(
{
psa_key_slot_t *slot;
psa_status_t status;
status = psa_get_transparent_key( handle, &slot,
PSA_KEY_USAGE_DERIVE,
operation->alg );
@ -5182,6 +5186,12 @@ psa_status_t psa_key_derivation_input_key(
psa_key_derivation_abort( operation );
return( status );
}
/* Passing a key object as a SECRET input unlocks the permission
* to output to a key object. */
if( step == PSA_KEY_DERIVATION_INPUT_SECRET )
operation->can_output_key = 1;
return( psa_key_derivation_input_internal( operation,
step, slot->attr.type,
slot->data.raw.data,

View File

@ -1888,7 +1888,11 @@ PSA key derivation setup: bad algorithm
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_setup:PSA_ALG_CATEGORY_KEY_DERIVATION:PSA_ERROR_NOT_SUPPORTED
PSA key derivation: HKDF-SHA-256, good case
PSA key derivation: HKDF-SHA-256, good case, direct output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_DERIVE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_TYPE_NONE:PSA_SUCCESS
PSA key derivation: HKDF-SHA-256, good case, key output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_DERIVE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_TYPE_DERIVE:PSA_SUCCESS
@ -1900,14 +1904,28 @@ PSA key derivation: HKDF-SHA-256, bad key type
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_RAW_DATA:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ERROR_INVALID_ARGUMENT:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_ERROR_BAD_STATE:PSA_KEY_TYPE_NONE:PSA_ERROR_BAD_STATE
PSA key derivation: HKDF-SHA-256, direct secret
PSA key derivation: HKDF-SHA-256, bad key type, key output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
# Whether we get NOT_PERMITTED or BAD_STATE for the output is an implementation
# detail.
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_RAW_DATA:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ERROR_INVALID_ARGUMENT:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_ERROR_BAD_STATE:PSA_KEY_TYPE_RAW_DATA:PSA_ERROR_NOT_PERMITTED
PSA key derivation: HKDF-SHA-256, direct secret, direct output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_NONE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_TYPE_NONE:PSA_SUCCESS
PSA key derivation: HKDF-SHA-256, direct empty secret
PSA key derivation: HKDF-SHA-256, direct empty secret, direct output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_TYPE_NONE:PSA_SUCCESS
PSA key derivation: HKDF-SHA-256, direct secret, key output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_NONE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_TYPE_RAW_DATA:PSA_ERROR_NOT_PERMITTED
PSA key derivation: HKDF-SHA-256, direct empty secret, key output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_TYPE_RAW_DATA:PSA_ERROR_NOT_PERMITTED
PSA key derivation: HKDF-SHA-256, RAW_DATA key as salt
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_RAW_DATA:"412073616c74":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_DERIVE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_TYPE_DERIVE:PSA_SUCCESS
@ -1916,10 +1934,16 @@ PSA key derivation: HKDF-SHA-256, RAW_DATA key as info
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_DERIVE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_RAW_DATA:"4120696e666f":PSA_SUCCESS:PSA_KEY_TYPE_DERIVE:PSA_SUCCESS
PSA key derivation: HKDF-SHA-256, DERIVE key as salt
PSA key derivation: HKDF-SHA-256, DERIVE key as salt, direct output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_DERIVE:"412073616c74":PSA_ERROR_INVALID_ARGUMENT:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_DERIVE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ERROR_BAD_STATE:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_ERROR_BAD_STATE:PSA_KEY_TYPE_NONE:PSA_ERROR_BAD_STATE
PSA key derivation: HKDF-SHA-256, DERIVE key as salt, key output
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
# Whether we get NOT_PERMITTED or BAD_STATE for the output is an implementation
# detail.
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_DERIVE:"412073616c74":PSA_ERROR_INVALID_ARGUMENT:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_DERIVE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ERROR_BAD_STATE:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_NONE:"":PSA_ERROR_BAD_STATE:PSA_KEY_TYPE_RAW_DATA:PSA_ERROR_BAD_STATE
PSA key derivation: HKDF-SHA-256, DERIVE key as info
depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C
derive_input:PSA_ALG_HKDF(PSA_ALG_SHA_256):PSA_KEY_DERIVATION_INPUT_SALT:PSA_KEY_TYPE_NONE:"":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_SECRET:PSA_KEY_TYPE_DERIVE:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_SUCCESS:PSA_KEY_DERIVATION_INPUT_INFO:PSA_KEY_TYPE_DERIVE:"4120696e666f":PSA_ERROR_INVALID_ARGUMENT:PSA_KEY_TYPE_NONE:PSA_ERROR_BAD_STATE