commit 74a77f68897347053abea73c17e4cb045096c9c9 Author: teor teor@riseup.net Date: Mon May 18 14:24:05 2020 +1000

Rewrite ed25519 key loading to be more robust

Tolerate being called early during bootstrap, and being called on old tor versions without ed25519. --- lib/chutney/TorNet.py | 83 ++++++++++++++++++++++++++++----------------------- 1 file changed, 46 insertions(+), 37 deletions(-)

diff --git a/lib/chutney/TorNet.py b/lib/chutney/TorNet.py index 2eef368..5d28763 100644 --- a/lib/chutney/TorNet.py +++ b/lib/chutney/TorNet.py @@ -866,48 +866,53 @@ class LocalNodeBuilder(NodeBuilder):

class LocalNodeController(NodeController):

- def _setEd25519Id(self): + def __init__(self, env): + NodeController.__init__(self, env) + self._env = env + + def _loadEd25519Id(self): """ - Read the ed25519 identity key for this router, and set up the - 'ed25519_id' entry in the Environ + Read the ed25519 identity key for this router, encode it using + base64, strip trailing padding, and return it. + + If the file does not exist, returns None. + + Raises a ValueError if the file appears to be corrupt. """ datadir = self._env['dir'] key_file = os.path.join(datadir, 'keys', "ed25519_master_id_public_key") - EXPECTED_ED25519_FILE_SIZE = 64 - CURRENT_FILE_SIZE = os.stat(key_file).st_size + # If we're called early during bootstrap, the file won't have been + # created yet. (And some very old tor versions don't have ed25519.) if not os.path.exists(key_file): - print(("File {} does not exist. " - "Are you running a very old tor version?").format(key_file)) - return - elif CURRENT_FILE_SIZE != EXPECTED_ED25519_FILE_SIZE: - raise ValueError(("The current size of the file is {} bytes, " - "which is not matching the expected value of " - "{} bytes").format(CURRENT_FILE_SIZE, - EXPECTED_ED25519_FILE_SIZE)) - else: - with open(key_file, 'rb') as f: - ED25519_KEY_POSITION = 32 - f.seek(ED25519_KEY_POSITION) - rest_file = f.read() - encoded_value = base64.b64encode(rest_file) - ed25519_id = encoded_value.decode('utf-8').replace('=', '') - EXPECTED_ED25519_BASE64_KEY_SIZE = 43 - CURRENT_ED25519_BASE64_KEY_SIZE = len(ed25519_id) - if (CURRENT_ED25519_BASE64_KEY_SIZE != - EXPECTED_ED25519_BASE64_KEY_SIZE): - raise ValueError(("The current length of the key is {}, " - "which is not matching the expected " - "length of {}") - .format(CURRENT_ED25519_BASE64_KEY_SIZE, - EXPECTED_ED25519_BASE64_KEY_SIZE)) - else: - self._env['ed25519_id'] = ed25519_id + debug(("File {} does not exist. Are you running a very old tor " + "version?").format(key_file)) + return None

- def __init__(self, env): - NodeController.__init__(self, env) - self._env = env - self._setEd25519Id() + EXPECTED_ED25519_FILE_SIZE = 64 + key_file_size = os.stat(key_file).st_size + if key_file_size != EXPECTED_ED25519_FILE_SIZE: + raise ValueError( + ("The current size of the file is {} bytes, which is not" + "matching the expected value of {} bytes") + .format(key_file_size, EXPECTED_ED25519_FILE_SIZE)) + + with open(key_file, 'rb') as f: + ED25519_KEY_POSITION = 32 + f.seek(ED25519_KEY_POSITION) + rest_file = f.read() + encoded_value = base64.b64encode(rest_file) + # tor strips trailing base64 padding + ed25519_id = encoded_value.decode('utf-8').replace('=', '') + EXPECTED_ED25519_BASE64_KEY_SIZE = 43 + key_base64_size = len(ed25519_id) + if (key_base64_size != EXPECTED_ED25519_BASE64_KEY_SIZE): + raise ValueError( + ("The current length of the key is {}, which is not " + "matching the expected length of {}") + .format(key_base64_size, + EXPECTED_ED25519_BASE64_KEY_SIZE)) + return ed25519_id

def getNick(self): """Return the nickname for this node.""" @@ -921,11 +926,15 @@ class LocalNodeController(NodeController): return 0

def getEd25519Id(self): - """Return the value of ed25519 key""" + """Return the base64-encoded ed25519 public key of this node.""" try: return self._env['ed25519_id'] except KeyError: - return None + ed25519_id = self._loadEd25519Id() + # cache a copy for later + if ed25519_id: + self._env['ed25519_id'] = ed25519_id + return ed25519_id

def getBridgeClient(self): """Return the bridge client flag for this node."""