diff --git a/scripts/generate_tls_handshake_tests.py b/scripts/generate_tls_handshake_tests.py new file mode 100755 index 000000000..1e9dbb944 --- /dev/null +++ b/scripts/generate_tls_handshake_tests.py @@ -0,0 +1,219 @@ +#!/usr/bin/env python3 + +""" +Generate miscellaneous TLS test cases relating to the handshake. +""" + +# Copyright The Mbed TLS Contributors +# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + +import argparse +import os +import sys +from typing import Optional + +from mbedtls_framework import tls_test_case +from mbedtls_framework import typing_util +from mbedtls_framework.tls_test_case import Side, Version +import translate_ciphers + + +# Assume that a TLS 1.2 ClientHello used in these tests will be at most +# this many bytes long. +TLS12_CLIENT_HELLO_ASSUMED_MAX_LENGTH = 255 + +# Minimum handshake fragment length that Mbed TLS supports. +TLS_HANDSHAKE_FRAGMENT_MIN_LENGTH = 4 + +def write_tls_handshake_defragmentation_test( + #pylint: disable=too-many-arguments + out: typing_util.Writable, + side: Side, + length: Optional[int], + version: Optional[Version] = None, + cipher: Optional[str] = None, + etm: Optional[bool] = None, #encrypt-then-mac (only relevant for CBC) + variant: str = '' +) -> None: + """Generate one TLS handshake defragmentation test. + + :param out: file to write to. + :param side: which side is Mbed TLS. + :param length: fragment length, or None to not fragment. + :param version: protocol version, if forced. + """ + #pylint: disable=chained-comparison,too-many-branches,too-many-statements + + our_args = '' + their_args = '' + + if length is None: + description = 'no fragmentation, for reference' + else: + description = 'len=' + str(length) + if version is not None: + description += ', TLS 1.' + str(version.value) + description = f'Handshake defragmentation on {side.name.lower()}: {description}' + tc = tls_test_case.TestCase(description) + + if version is not None: + their_args += ' ' + version.openssl_option() + # Emit a version requirement, because we're forcing the version via + # OpenSSL, not via Mbed TLS, and the automatic depdendencies in + # ssl-opt.sh only handle forcing the version via Mbed TLS. + tc.requirements.append(version.requires_command()) + if side == Side.SERVER and version == Version.TLS12 and \ + length is not None and \ + length <= TLS12_CLIENT_HELLO_ASSUMED_MAX_LENGTH: + # Server-side ClientHello defragmentation is only supported in + # the TLS 1.3 message parser. When that parser sees an 1.2-only + # ClientHello, it forwards the reassembled record to the + # TLS 1.2 ClientHello parser so the ClientHello can be fragmented. + # When TLS 1.3 support is disabled in the server (at compile-time + # or at runtime), the TLS 1.2 ClientHello parser only sees + # the first fragment of the ClientHello. + tc.requirements.append('requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3') + tc.description += ' with 1.3 support' + + # To guarantee that the handhake messages are large enough and need to be + # split into fragments, the tests require certificate authentication. + # The party in control of the fragmentation operations is OpenSSL and + # will always use server5.crt (548 Bytes). + if length is not None and \ + length >= TLS_HANDSHAKE_FRAGMENT_MIN_LENGTH: + tc.requirements.append('requires_certificate_authentication') + if version == Version.TLS12 and side == Side.CLIENT: + #The server uses an ECDSA cert, so make sure we have a compatible key exchange + tc.requirements.append( + 'requires_config_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED') + else: + # This test case may run in a pure-PSK configuration. OpenSSL doesn't + # allow this by default with TLS 1.3. + their_args += ' -allow_no_dhe_kex' + + if length is None: + forbidden_patterns = [ + 'waiting for more fragments', + ] + wanted_patterns = [] + elif length < TLS_HANDSHAKE_FRAGMENT_MIN_LENGTH: + their_args += ' -split_send_frag ' + str(length) + tc.exit_code = 1 + forbidden_patterns = [] + wanted_patterns = [ + 'handshake message too short: ' + str(length), + 'SSL - An invalid SSL record was received', + ] + if side == Side.SERVER: + wanted_patterns[0:0] = ['<= parse client hello'] + elif version == Version.TLS13: + wanted_patterns[0:0] = ['=> ssl_tls13_process_server_hello'] + else: + their_args += ' -split_send_frag ' + str(length) + forbidden_patterns = [] + wanted_patterns = [ + 'reassembled record', + fr'initial handshake fragment: {length}, 0\.\.{length} of [0-9]\+', + fr'subsequent handshake fragment: [0-9]\+, {length}\.\.', + fr'Prepare: waiting for more handshake fragments {length}/', + fr'Consume: waiting for more handshake fragments {length}/', + ] + + if cipher is not None: + mbedtls_cipher = translate_ciphers.translate_mbedtls(cipher) + if side == Side.CLIENT: + our_args += ' force_ciphersuite=' + mbedtls_cipher + if 'NULL' in cipher: + their_args += ' -cipher ALL@SECLEVEL=0:COMPLEMENTOFALL@SECLEVEL=0' + else: + # For TLS 1.2, when Mbed TLS is the server, we must force the + # cipher suite on the client side, because passing + # force_ciphersuite to ssl_server2 would force a TLS-1.2-only + # server, which does not support a fragmented ClientHello. + tc.requirements.append('requires_ciphersuite_enabled ' + mbedtls_cipher) + their_args += ' -cipher ' + translate_ciphers.translate_ossl(cipher) + if 'NULL' in cipher: + their_args += '@SECLEVEL=0' + + if etm is not None: + if etm: + tc.requirements.append('requires_config_enabled MBEDTLS_SSL_ENCRYPT_THEN_MAC') + our_args += ' etm=' + str(int(etm)) + (wanted_patterns if etm else forbidden_patterns)[0:0] = [ + 'using encrypt then mac', + ] + + tc.description += variant + + if side == Side.CLIENT: + tc.client = '$P_CLI debug_level=4' + our_args + tc.server = '$O_NEXT_SRV' + their_args + tc.wanted_client_patterns = wanted_patterns + tc.forbidden_client_patterns = forbidden_patterns + else: + their_args += ' -cert $DATA_FILES_PATH/server5.crt -key $DATA_FILES_PATH/server5.key' + our_args += ' auth_mode=required' + tc.client = '$O_NEXT_CLI' + their_args + tc.server = '$P_SRV debug_level=4' + our_args + tc.wanted_server_patterns = wanted_patterns + tc.forbidden_server_patterns = forbidden_patterns + tc.write(out) + + +CIPHERS_FOR_TLS12_HANDSHAKE_DEFRAGMENTATION = [ + (None, 'default', None), + ('TLS_ECDHE_ECDSA_WITH_NULL_SHA', 'null', None), + ('TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256', 'ChachaPoly', None), + ('TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256', 'GCM', None), + ('TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256', 'CBC, etm=n', False), + ('TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256', 'CBC, etm=y', True), +] + +def write_tls_handshake_defragmentation_tests(out: typing_util.Writable) -> None: + """Generate TLS handshake defragmentation tests.""" + for side in Side.CLIENT, Side.SERVER: + write_tls_handshake_defragmentation_test(out, side, None) + for length in [512, 513, 256, 128, 64, 36, 32, 16, 13, 5, 4, 3]: + write_tls_handshake_defragmentation_test(out, side, length, + Version.TLS13) + if length == 4: + for (cipher_suite, nickname, etm) in \ + CIPHERS_FOR_TLS12_HANDSHAKE_DEFRAGMENTATION: + write_tls_handshake_defragmentation_test( + out, side, length, Version.TLS12, + cipher=cipher_suite, etm=etm, + variant=', '+nickname) + else: + write_tls_handshake_defragmentation_test(out, side, length, + Version.TLS12) + + +def write_handshake_tests(out: typing_util.Writable) -> None: + """Generate handshake tests.""" + out.write(f"""\ +# Miscellaneous tests related to the TLS handshake layer. +# +# Automatically generated by {os.path.basename(sys.argv[0])}. Do not edit! + +# Copyright The Mbed TLS Contributors +# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + +""") + write_tls_handshake_defragmentation_tests(out) + out.write("""\ +# End of automatically generated file. +""") + +def main() -> None: + """Command line entry point.""" + parser = argparse.ArgumentParser() + parser = argparse.ArgumentParser(description=__doc__) + parser.add_argument('-o', '--output', + default='tests/opt-testcases/handshake-generated.sh', + help='Output file (default: tests/opt-testcases/handshake-generated.sh)') + args = parser.parse_args() + with open(args.output, 'w') as out: + write_handshake_tests(out) + +if __name__ == '__main__': + main() diff --git a/scripts/mbedtls_framework/tls_test_case.py b/scripts/mbedtls_framework/tls_test_case.py new file mode 100644 index 000000000..73bb039a8 --- /dev/null +++ b/scripts/mbedtls_framework/tls_test_case.py @@ -0,0 +1,101 @@ +"""Library for constructing an Mbed TLS ssl-opt test case. +""" + +# Copyright The Mbed TLS Contributors +# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + +import enum +import re +from typing import List + +from . import typing_util + + +class TestCase: + """Data about an ssl-opt test case.""" + #pylint: disable=too-few-public-methods + + def __init__(self, description: str) -> None: + # List of shell snippets to call before run_test, typically + # calls to requires_xxx functions. + self.requirements = [] #type: List[str] + # Test case description (first argument to run_test). + self.description = description + # Client command line. + # This will be placed directly inside double quotes in the shell script. + self.client = '$P_CLI' + # Server command line. + # This will be placed directly inside double quotes in the shell script. + self.server = '$P_SRV' + # Expected client exit code. + self.exit_code = 0 + + # Note that all patterns matched in the logs are in BRE + # (Basic Regular Expression) syntax, more precisely in the BRE + # dialect that is the default for GNU grep. The main difference + # with Python regular expressions is that the operators for + # grouping `\(...\)`, alternation `x\|y`, option `x\?`, + # one-or-more `x\+` and repetition ranges `x\{M,N\}` must be + # preceded by a backslash. The characters `()|?+{}` stand for + # themselves. + + # BRE for text that must be present in the client log (run_test -c). + self.wanted_client_patterns = [] #type: List[str] + # BRE for text that must be present in the server log (run_test -s). + self.wanted_server_patterns = [] #type: List[str] + # BRE for text that must not be present in the client log (run_test -C). + self.forbidden_client_patterns = [] #type: List[str] + # BRE for text that must not be present in the server log (run_test -S). + self.forbidden_server_patterns = [] #type: List[str] + + @staticmethod + def _quote(raw: str) -> str: + """Quote the given string for sh. + + Use double quotes, because that's currently the norm in ssl-opt.sh. + """ + return '"' + re.sub(r'([$"\\`])', r'\\\1', raw) + '"' + + def write(self, out: typing_util.Writable) -> None: + """Write the test case to the specified file.""" + for req in self.requirements: + out.write(req + '\n') + out.write(f'run_test {self._quote(self.description)} \\\n') + out.write(f' "{self.server}" \\\n') + out.write(f' "{self.client}" \\\n') + out.write(f' {self.exit_code}') + for pat in self.wanted_server_patterns: + out.write(' \\\n -s ' + self._quote(pat)) + for pat in self.forbidden_server_patterns: + out.write(' \\\n -S ' + self._quote(pat)) + for pat in self.wanted_client_patterns: + out.write(' \\\n -c ' + self._quote(pat)) + for pat in self.forbidden_client_patterns: + out.write(' \\\n -C ' + self._quote(pat)) + out.write('\n\n') + + +class Side(enum.Enum): + CLIENT = 0 + SERVER = 1 + +class Version(enum.Enum): + """TLS protocol version. + + This class doesn't know about DTLS yet. + """ + + TLS12 = 2 + TLS13 = 3 + + def force_version(self) -> str: + """Argument to pass to ssl_client2 or ssl_server2 to force this version.""" + return f'force_version=tls1{self.value}' + + def openssl_option(self) -> str: + """Option to pass to openssl s_client or openssl s_server to select this version.""" + return f'-tls1_{self.value}' + + def requires_command(self) -> str: + """Command to require this protocol version in an ssl-opt.sh test case.""" + return 'requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_' + str(self.value)