crypto_config.h: Don't list mechanisms that are not implemented

Don't list mechanisms that are not implemented in
`include/psa/crypto_config.h`, even commented out. Uncommenting them
wouldn't help anyway: they don't work. Having them listed, even commented
out, causes `find_dependencies_not_implemented()` in `psa_test_case.py` to
consider those mechanisms to be implemented, and thus causes
`generate_psa_tests.py` to generate test cases that cannot be executed.

The affected mechanisms are:

* `PSA_ALG_CBC_MAC` (`PSA_WANT_ALG_CBC_MAC`)
* `PSA_ALG_XTS` (`PSA_WANT_ALG_XTS`)
* `PSA_ECC_FAMILY_SECP_K1` 224-bit (`PSA_WANT_ECC_SECP_K1_224`)

Also remove the affected mechanisms from configuration adjustment files,
since that is code that can never be triggered.

There were already no generated test cases for SECP224K1 because
`PSA_WANT_ECC_SECP_K1_224` was already detected as a dependency that cannot
be implemented, because that is not a valid size: PSA defines SECP224K1 as
225-bit, and `crypto_knowledge.py` follows suite, so `generate_psa_tests.py`
saw `PSA_WANT_ECC_SECP_K1_225` in its enumeration but skipped it because it
was never mentioned in `crypto_config.h`.

This causes generated PSA tests to no longer include positive test cases for
`PSA_ALG_CBC_MAC` and `PSA_ALG_XTS`.

Signed-off-by: Gilles Peskine <[email protected]>

drivers/builtin/include/mbedtls/config_adjust_legacy_from_psa.h

@@ -68,7 +68,6 @@
     (defined(PSA_WANT_ECC_SECP_R1_384) && !defined(MBEDTLS_PSA_ACCEL_ECC_SECP_R1_384)) || \
     (defined(PSA_WANT_ECC_SECP_R1_521) && !defined(MBEDTLS_PSA_ACCEL_ECC_SECP_R1_521)) || \
     (defined(PSA_WANT_ECC_SECP_K1_192) && !defined(MBEDTLS_PSA_ACCEL_ECC_SECP_K1_192)) || \
-    (defined(PSA_WANT_ECC_SECP_K1_224) && !defined(MBEDTLS_PSA_ACCEL_ECC_SECP_K1_224)) || \
     (defined(PSA_WANT_ECC_SECP_K1_256) && !defined(MBEDTLS_PSA_ACCEL_ECC_SECP_K1_256))
 #define MBEDTLS_PSA_ECC_ACCEL_INCOMPLETE_CURVES
 #define MBEDTLS_PSA_ECC_ACCEL_INCOMPLETE_WEIERSTRASS_CURVES
@@ -224,17 +223,6 @@
 #endif /* missing accel */
 #endif /* PSA_WANT_ECC_SECP_K1_192 */
 
-#if defined(PSA_WANT_ECC_SECP_K1_224)
-#if !defined(MBEDTLS_PSA_ACCEL_ECC_SECP_K1_224) || \
-    defined(MBEDTLS_PSA_ECC_ACCEL_INCOMPLETE_KEY_TYPES) || \
-    defined(MBEDTLS_PSA_ECC_ACCEL_INCOMPLETE_ALGS)
-#define MBEDTLS_PSA_BUILTIN_ECC_SECP_K1_224 1
-#define MBEDTLS_ECP_DP_SECP224K1_ENABLED
-/* https://github.com/Mbed-TLS/mbedtls/issues/3541 */
-#error "SECP224K1 is buggy via the PSA API in Mbed TLS."
-#endif /* missing accel */
-#endif /* PSA_WANT_ECC_SECP_K1_224 */
-
 #if defined(PSA_WANT_ECC_SECP_K1_256)
 #if !defined(MBEDTLS_PSA_ACCEL_ECC_SECP_K1_256) || \
     defined(MBEDTLS_PSA_ECC_ACCEL_INCOMPLETE_KEY_TYPES) || \
@@ -781,13 +769,6 @@
 #define PSA_HAVE_SOFT_BLOCK_CIPHER 1
 #endif
 
-#if defined(PSA_WANT_ALG_CBC_MAC)
-#if !defined(MBEDTLS_PSA_ACCEL_ALG_CBC_MAC)
-#error "CBC-MAC is not yet supported via the PSA API in Mbed TLS."
-#define MBEDTLS_PSA_BUILTIN_ALG_CBC_MAC 1
-#endif /* !MBEDTLS_PSA_ACCEL_ALG_CBC_MAC */
-#endif /* PSA_WANT_ALG_CBC_MAC */
-
 #if defined(PSA_WANT_ALG_CMAC)
 #if !defined(MBEDTLS_PSA_ACCEL_ALG_CMAC) || \
     defined(PSA_HAVE_SOFT_BLOCK_CIPHER)

drivers/builtin/include/mbedtls/config_adjust_psa_superset_legacy.h

@@ -136,13 +136,6 @@
 #endif /* PSA_WANT_ECC_SECP_K1_192 */
 #endif /* MBEDTLS_ECP_DP_SECP192K1_ENABLED */
 
-/* SECP224K1 is buggy via the PSA API (https://github.com/Mbed-TLS/mbedtls/issues/3541) */
-#if 0 && defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
-#if !defined(PSA_WANT_ECC_SECP_K1_224)
-#define PSA_WANT_ECC_SECP_K1_224 1
-#endif /* PSA_WANT_ECC_SECP_K1_224 */
-#endif /* MBEDTLS_ECP_DP_SECP224K1_ENABLED */
-
 #if defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
 #if !defined(PSA_WANT_ECC_SECP_K1_256)
 #define PSA_WANT_ECC_SECP_K1_256 1

drivers/builtin/src/psa_crypto_cipher.c

@@ -71,9 +71,6 @@ static psa_status_t mbedtls_cipher_validate_values(
 #if !defined(PSA_WANT_ALG_OFB)
     MBEDTLS_ASSUME(alg != PSA_ALG_OFB);
 #endif
-#if !defined(PSA_WANT_ALG_XTS)
-    MBEDTLS_ASSUME(alg != PSA_ALG_XTS);
-#endif
 #if !defined(PSA_WANT_ALG_ECB_NO_PADDING)
     MBEDTLS_ASSUME(alg != PSA_ALG_ECB_NO_PADDING);
 #endif

include/psa/crypto_config.h

@@ -36,10 +36,6 @@
  * \{
  */
 
-/*
- * CBC-MAC is not yet supported via the PSA API in Mbed TLS.
- */
-//#define PSA_WANT_ALG_CBC_MAC                    1
 #define PSA_WANT_ALG_CBC_NO_PADDING             1
 #define PSA_WANT_ALG_CBC_PKCS7                  1
 #define PSA_WANT_ALG_CCM                        1
@@ -82,22 +78,12 @@
 #define PSA_WANT_ALG_TLS12_PSK_TO_MS            1
 #define PSA_WANT_ALG_TLS12_ECJPAKE_TO_PMS       1
 
-/* XTS is not yet supported via the PSA API in Mbed TLS.
- * Note: when adding support, also adjust include/mbedtls/config_psa.h */
-//#define PSA_WANT_ALG_XTS                        1
-
 #define PSA_WANT_ECC_BRAINPOOL_P_R1_256         1
 #define PSA_WANT_ECC_BRAINPOOL_P_R1_384         1
 #define PSA_WANT_ECC_BRAINPOOL_P_R1_512         1
 #define PSA_WANT_ECC_MONTGOMERY_255             1
 #define PSA_WANT_ECC_MONTGOMERY_448             1
 #define PSA_WANT_ECC_SECP_K1_192                1
-/*
- * SECP224K1 is buggy via the PSA API in Mbed TLS
- * (https://github.com/Mbed-TLS/mbedtls/issues/3541). Thus, do not enable it by
- * default.
- */
-//#define PSA_WANT_ECC_SECP_K1_224                1
 #define PSA_WANT_ECC_SECP_K1_256                1
 #define PSA_WANT_ECC_SECP_R1_192                1
 #define PSA_WANT_ECC_SECP_R1_224                1

scripts/config.py

@@ -22,8 +22,6 @@
 PSA_SYMBOL_REGEXP = re.compile(r'^PSA_.*')
 
 PSA_UNSUPPORTED_FEATURE = frozenset([
-    'PSA_WANT_ALG_CBC_MAC',
-    'PSA_WANT_ALG_XTS',
     'PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_DERIVE',
     'PSA_WANT_KEY_TYPE_DH_KEY_PAIR_DERIVE'
 ])
@@ -33,10 +31,6 @@
     'PSA_WANT_KEY_TYPE_RSA_KEY_PAIR'
 ])
 
-PSA_UNSTABLE_FEATURE = frozenset([
-    'PSA_WANT_ECC_SECP_K1_224'
-])
-
 # The goal of the full configuration is to have everything that can be tested
 # together. This includes deprecated or insecure options. It excludes:
 # * Options that require additional build dependencies or unusual hardware.
@@ -82,7 +76,6 @@
     'MBEDTLS_PSA_STATIC_KEY_SLOT_BUFFER_SIZE', # only relevant for embedded devices
     *PSA_UNSUPPORTED_FEATURE,
     *PSA_DEPRECATED_FEATURE,
-    *PSA_UNSTABLE_FEATURE
 ])
 
 def is_boolean_setting(name, value):
@@ -177,8 +170,6 @@ def set(self, name, value=None):
 
         if name in PSA_UNSUPPORTED_FEATURE:
             raise ValueError(f'Feature is unsupported: \'{name}\'')
-        if name in PSA_UNSTABLE_FEATURE:
-            raise ValueError(f'Feature is unstable: \'{name}\'')
 
         if name not in self.settings:
             self._get_configfile().templates.append((name, '', f'#define {name} '))

tests/configs/crypto_config_test_driver_extension.h

@@ -127,14 +127,6 @@
 #endif
 #endif
 
-#if defined(PSA_WANT_ECC_SECP_K1_224)
-#if defined(MBEDTLS_PSA_ACCEL_ECC_SECP_K1_224)
-#undef MBEDTLS_PSA_ACCEL_ECC_SECP_K1_224
-#else
-#define MBEDTLS_PSA_ACCEL_ECC_SECP_K1_224 1
-#endif
-#endif
-
 #if defined(PSA_WANT_ECC_SECP_K1_256)
 #if defined(MBEDTLS_PSA_ACCEL_ECC_SECP_K1_256)
 #undef MBEDTLS_PSA_ACCEL_ECC_SECP_K1_256
@@ -367,14 +359,6 @@
 #endif
 #endif
 
-#if defined(PSA_WANT_ALG_XTS)
-#if defined(MBEDTLS_PSA_ACCEL_ALG_XTS)
-#undef MBEDTLS_PSA_ACCEL_ALG_XTS
-#else
-#define MBEDTLS_PSA_ACCEL_ALG_XTS 1
-#endif
-#endif
-
 #if defined(PSA_WANT_ALG_CHACHA20_POLY1305)
 #if defined(MBEDTLS_PSA_ACCEL_ALG_CHACHA20_POLY1305)
 #undef MBEDTLS_PSA_ACCEL_ALG_CHACHA20_POLY1305
@@ -600,14 +584,6 @@
 #endif
 #endif
 
-#if defined(PSA_WANT_ALG_CBC_MAC)
-#if defined(MBEDTLS_PSA_ACCEL_ALG_CBC_MAC)
-#undef MBEDTLS_PSA_ACCEL_ALG_CBC_MAC
-#else
-#define MBEDTLS_PSA_ACCEL_ALG_CBC_MAC 1
-#endif
-#endif
-
 #if defined(PSA_WANT_ALG_HMAC)
 #if defined(MBEDTLS_PSA_ACCEL_ALG_HMAC)
 #undef MBEDTLS_PSA_ACCEL_ALG_HMAC