Merge pull request #9792 from gabor-mezei-arm/9157_minimal_tf_psa_crypto_config.py

Minimal `config.py` for TF-PSA-Crypto
diff --git a/framework b/framework
index a2c7694..150bf84 160000
--- a/framework
+++ b/framework
@@ -1 +1 @@
-Subproject commit a2c76945ca090f9dd099001d7c5158557f5a2036
+Subproject commit 150bf842819e8680a2733774cdceabf60ffbe164
diff --git a/scripts/config.py b/scripts/config.py
index cf0755b..db2bc57 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -398,7 +398,7 @@
                               for configfile in [self.mbedtls_configfile, self.crypto_configfile]
                               for (active, name, value, section) in configfile.parse_file()})
 
-    _crypto_regexp = re.compile(r'$PSA_.*')
+    _crypto_regexp = re.compile(r'^PSA_.*')
     def _get_configfile(self, name=None):
         """Find a config type for a setting name"""
 
diff --git a/tf-psa-crypto/scripts/config.py b/tf-psa-crypto/scripts/config.py
new file mode 100755
index 0000000..30b6067
--- /dev/null
+++ b/tf-psa-crypto/scripts/config.py
@@ -0,0 +1,209 @@
+#!/usr/bin/env python3
+
+"""TF PSA Crypto configuration file manipulation library and tool
+
+Basic usage, to read the TF PSA Crypto configuration:
+    config = TFPSACryptoConfig()
+    if 'PSA_WANT_ALG_MD5' in config: print('MD5 is enabled')
+"""
+
+## Copyright The Mbed TLS Contributors
+## SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+##
+
+import re
+import os
+import sys
+
+import framework_scripts_path # pylint: disable=unused-import
+from mbedtls_framework import config_common
+
+
+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'
+])
+
+PSA_DEPRECATED_FEATURE = frozenset([
+    'PSA_WANT_KEY_TYPE_ECC_KEY_PAIR',
+    '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.
+# * Options that make testing less effective.
+# * Options that are incompatible with other options, or more generally that
+#   interact with other parts of the code in such a way that a bulk enabling
+#   is not a good way to test them.
+# * Options that remove features.
+EXCLUDE_FROM_FULL = frozenset([
+    #pylint: disable=line-too-long
+    'MBEDTLS_AES_ONLY_128_BIT_KEY_LENGTH', # interacts with CTR_DRBG_128_BIT_KEY
+    'MBEDTLS_AES_USE_HARDWARE_ONLY', # hardware dependency
+    'MBEDTLS_BLOCK_CIPHER_NO_DECRYPT', # incompatible with ECB in PSA, CBC/XTS/NIST_KW/DES
+    'MBEDTLS_CTR_DRBG_USE_128_BIT_KEY', # interacts with ENTROPY_FORCE_SHA256
+    'MBEDTLS_DEPRECATED_REMOVED', # conflicts with deprecated options
+    'MBEDTLS_DEPRECATED_WARNING', # conflicts with deprecated options
+    'MBEDTLS_ECDH_VARIANT_EVEREST_ENABLED', # influences the use of ECDH in TLS
+    'MBEDTLS_ECP_WITH_MPI_UINT', # disables the default ECP and is experimental
+    'MBEDTLS_ENTROPY_FORCE_SHA256', # interacts with CTR_DRBG_128_BIT_KEY
+    'MBEDTLS_HAVE_SSE2', # hardware dependency
+    'MBEDTLS_MEMORY_BACKTRACE', # depends on MEMORY_BUFFER_ALLOC_C
+    'MBEDTLS_MEMORY_DEBUG', # depends on MEMORY_BUFFER_ALLOC_C
+    'MBEDTLS_NO_64BIT_MULTIPLICATION', # influences anything that uses bignum
+    'MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES', # removes a feature
+    'MBEDTLS_NO_PLATFORM_ENTROPY', # removes a feature
+    'MBEDTLS_NO_UDBL_DIVISION', # influences anything that uses bignum
+    'MBEDTLS_PSA_P256M_DRIVER_ENABLED', # influences SECP256R1 KeyGen/ECDH/ECDSA
+    'MBEDTLS_PLATFORM_NO_STD_FUNCTIONS', # removes a feature
+    'MBEDTLS_PSA_ASSUME_EXCLUSIVE_BUFFERS', # removes a feature
+    'MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG', # behavior change + build dependency
+    'MBEDTLS_PSA_CRYPTO_KEY_ID_ENCODES_OWNER', # interface and behavior change
+    'MBEDTLS_PSA_CRYPTO_SPM', # platform dependency (PSA SPM)
+    'MBEDTLS_PSA_INJECT_ENTROPY', # conflicts with platform entropy sources
+    'MBEDTLS_RSA_NO_CRT', # influences the use of RSA in X.509 and TLS
+    'MBEDTLS_SHA256_USE_A64_CRYPTO_ONLY', # interacts with *_USE_A64_CRYPTO_IF_PRESENT
+    'MBEDTLS_SHA256_USE_ARMV8_A_CRYPTO_ONLY', # interacts with *_USE_ARMV8_A_CRYPTO_IF_PRESENT
+    'MBEDTLS_SHA512_USE_A64_CRYPTO_ONLY', # interacts with *_USE_A64_CRYPTO_IF_PRESENT
+    'MBEDTLS_SHA256_USE_A64_CRYPTO_IF_PRESENT', # setting *_USE_ARMV8_A_CRYPTO is sufficient
+    'MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN', # build dependency (clang+memsan)
+    'MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND', # build dependency (valgrind headers)
+    *PSA_UNSUPPORTED_FEATURE,
+    *PSA_DEPRECATED_FEATURE,
+    *PSA_UNSTABLE_FEATURE
+])
+
+def is_boolean_setting(name, value):
+    """Is this a boolean setting?
+
+    Mbed TLS boolean settings are enabled if the preprocessor macro is
+    defined, and disabled if the preprocessor macro is not defined. The
+    macro definition line in the configuration file has an empty expansion.
+
+    PSA_WANT_xxx settings are also boolean, but when they are enabled,
+    they expand to a nonzero value. We leave them undefined when they
+    are disabled. (Setting them to 0 currently means to enable them, but
+    this might change to mean disabling them. Currently we just never set
+    them to 0.)
+    """
+    if re.match(PSA_SYMBOL_REGEXP, name):
+        return True
+    if not value:
+        return True
+    return False
+
+def is_seamless_alt(name):
+    """Whether the xxx_ALT symbol should be included in the full configuration.
+
+    Include alternative implementations of platform functions, which are
+    configurable function pointers that default to the built-in function.
+    This way we test that the function pointers exist and build correctly
+    without changing the behavior, and tests can verify that the function
+    pointers are used by modifying those pointers.
+
+    Exclude alternative implementations of library functions since they require
+    an implementation of the relevant functions and an xxx_alt.h header.
+    """
+    if name in (
+            'MBEDTLS_PLATFORM_GMTIME_R_ALT',
+            'MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT',
+            'MBEDTLS_PLATFORM_MS_TIME_ALT',
+            'MBEDTLS_PLATFORM_ZEROIZE_ALT',
+    ):
+        # Similar to non-platform xxx_ALT, requires platform_alt.h
+        return False
+    return name.startswith('MBEDTLS_PLATFORM_')
+
+def include_in_full(name):
+    """Rules for symbols in the "full" configuration."""
+    if name in EXCLUDE_FROM_FULL:
+        return False
+    if name.endswith('_ALT'):
+        return is_seamless_alt(name)
+    return True
+
+def full_adapter(name, value, active):
+    """Config adapter for "full"."""
+    if not is_boolean_setting(name, value):
+        return active
+    return include_in_full(name)
+
+
+class TFPSACryptoConfigFile(config_common.ConfigFile):
+    """Representation of a TF PSA Crypto configuration file."""
+
+    _path_in_tree = 'include/psa/crypto_config.h'
+    default_path = [_path_in_tree,
+                    os.path.join(os.path.dirname(__file__),
+                                 os.pardir,
+                                 _path_in_tree),
+                    os.path.join(os.path.dirname(os.path.dirname(os.path.abspath(__file__))),
+                                 _path_in_tree)]
+
+    def __init__(self, filename=None):
+        super().__init__(self.default_path, 'TF-PSA-Crypto', filename)
+
+
+class TFPSACryptoConfig(config_common.Config):
+    """Representation of the TF PSA Crypto configuration.
+
+    See the documentation of the `Config` class for methods to query
+    and modify the configuration.
+    """
+
+    def __init__(self, filename=None):
+        """Read the PSA crypto configuration files."""
+
+        super().__init__()
+        configfile = TFPSACryptoConfigFile(filename)
+        self.configfiles.append(configfile)
+        self.settings.update({name: config_common.Setting(configfile, active, name, value, section)
+                             for (active, name, value, section) in configfile.parse_file()})
+
+    def set(self, name, value=None):
+        """Set name to the given value and make it active."""
+
+        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} '))
+
+        # Default value for PSA macros is '1'
+        if not value and re.match(PSA_SYMBOL_REGEXP, name):
+            value = '1'
+
+        super().set(name, value)
+
+
+class TFPSACryptoConfigTool(config_common.ConfigTool):
+    """Command line TF PSA Crypto config file manipulation tool."""
+
+    def __init__(self):
+        super().__init__(TFPSACryptoConfigFile.default_path[0])
+        self.config = TFPSACryptoConfig(self.args.file)
+
+    def custom_parser_options(self):
+        """Adds TF PSA Crypto specific options for the parser."""
+
+        self.add_adapter(
+            'full', full_adapter,
+            """Uncomment most features.
+            Exclude alternative implementations and platform support options, as well as
+            some options that are awkward to test.
+            """)
+
+
+if __name__ == '__main__':
+    sys.exit(TFPSACryptoConfigTool().main())