Add config.py for TF PSA Crypto

Add minimal required classes to use `get`, `set` and `unset` operations.

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>

tf-psa-crypto/scripts/tf_psa_crypto_config.py

@@ -0,0 +1,95 @@
+#!/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 os
+import sys
+
+import framework_scripts_path # pylint: disable=unused-import
+from mbedtls_framework import config_common
+
+
+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_UNSTABLE_FEATURE = frozenset([
+    'PSA_WANT_ECC_SECP_K1_224'
+])
+
+
+class TfPSACryptoConfigFile(config_common.ConfigFile):
+    """Representation of a TF PSA Crypto configuration file."""
+
+    _path_in_tree = 'tf-psa-crypto/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.abspath(os.path.dirname(__file__))),
+                                 _path_in_tree)]
+
+    def __init__(self, filename=None):
+        super().__init__(self.default_path, '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, *configfiles):
+        """Read the PSA crypto configuration files."""
+
+        super().__init__()
+        self.configfiles.extend(configfiles)
+        self.settings.update({name: config_common.Setting(configfile, active, name, value, section)
+                             for configfile in configfiles
+                             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 name.startswith('PSA_') and not value:
+            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], single_config=False)
+        configfiles = [TfPSACryptoConfigFile(file) for file in self.args.file]
+        self.config = TfPSACryptoConfig(*configfiles)
+
+    def custom_parser_options(self):
+        """Adds TF PSA Crypto specific options for the parser."""
+
+
+if __name__ == '__main__':
+    sys.exit(TfPSACryptoConfigTool().main())