commit d82a70a4fb874ca295c1644e3c77f24afddcbf06 Author: Damian Johnson atagar@torproject.org Date: Wed Nov 28 21:16:04 2012 -0800

Minor whitespace changes

Just adding empty lines in a few spots to improve readability. Conventionally we include blank lines between pydoc description, :param:, :returns:, and :raises: entries. It also find that it helps to have empty lines around conditionals and comments, though that might just be a matter of taste.

No functional changes. --- stem/descriptor/server_descriptor.py | 29 ++++++++++++++++++++++++++--- test/mocking.py | 1 - 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/stem/descriptor/server_descriptor.py b/stem/descriptor/server_descriptor.py index bed6b89..a1d4055 100644 --- a/stem/descriptor/server_descriptor.py +++ b/stem/descriptor/server_descriptor.py @@ -600,21 +600,24 @@ class RelayDescriptor(ServerDescriptor):

def digest(self): """ - Get the digest for this descriptor. - If the digest has not already been calculated it will be done inline. + Provides the digest of our descriptor's content. + :raises: ValueError if the digest canot be calculated + :returns: the digest string encoded in uppercase hex """

if self._digest is None: # Digest is calculated from everything in the # descriptor except the router-signature. + raw_descriptor = str(self) start_token = "router " sig_token = "\nrouter-signature\n" start = raw_descriptor.find(start_token) sig_start = raw_descriptor.find(sig_token) end = sig_start + len(sig_token) + if start >= 0 and sig_start > 0 and end > start: for_digest = raw_descriptor[start:end] digest_hash = hashlib.sha1(for_digest) @@ -627,15 +630,19 @@ class RelayDescriptor(ServerDescriptor): def _validate_content(self): """ Validates that the descriptor content matches the signature. + :raises: ValueError if the signature does not match the content """

key_as_bytes = RelayDescriptor._get_key_bytes(self.signing_key)

# ensure the fingerprint is a hash of the signing key + if self.fingerprint: # calculate the signing key hash + key_der_as_hash = hashlib.sha1(key_as_bytes).hexdigest() + if key_der_as_hash != self.fingerprint.lower(): log.warn("Signing key hash: %s != fingerprint: %s" % (key_der_as_hash, self.fingerprint.lower())) raise ValueError("Fingerprint does not match hash") @@ -650,19 +657,28 @@ class RelayDescriptor(ServerDescriptor): from Crypto.Util.number import bytes_to_long, long_to_bytes

# get the ASN.1 sequence + seq = asn1.DerSequence() seq.decode(key_as_der) modulus = seq[0] public_exponent = seq[1] # should always be 65537

sig_as_bytes = RelayDescriptor._get_key_bytes(self.signature) + # convert the descriptor signature to an int + sig_as_long = bytes_to_long(sig_as_bytes) + # use the public exponent[e] & the modulus[n] to decrypt the int + decrypted_int = pow(sig_as_long, public_exponent, modulus) + # block size will always be 128 for a 1024 bit key + blocksize = 128 + # convert the int to a byte array. + decrypted_bytes = long_to_bytes(decrypted_int, blocksize)

############################################################################ @@ -676,6 +692,7 @@ class RelayDescriptor(ServerDescriptor): ## More info here http://www.ietf.org/rfc/rfc2313.txt ## esp the Notes in section 8.1 ############################################################################ + try: if decrypted_bytes.index('\x00\x01') != 0: raise ValueError("Verification failed, identifier missing") @@ -684,16 +701,20 @@ class RelayDescriptor(ServerDescriptor):

try: identifier_offset = 2 + # find the separator seperator_index = decrypted_bytes.index('\x00', identifier_offset) except ValueError: raise ValueError("Verification failed, seperator not found")

digest = decrypted_bytes[seperator_index+1:] + # The local digest is stored in uppercase hex; # - so decode it from hex # - and convert it to lower case + local_digest = self.digest().lower().decode('hex') + if digest != local_digest: raise ValueError("Decrypted digest does not match local digest")

@@ -701,6 +722,7 @@ class RelayDescriptor(ServerDescriptor): entries = dict(entries) # shallow copy since we're destructive

# handles fields only in server descriptors + for keyword, values in entries.items(): value, block_contents = values[0] line = "%s %s" % (keyword, value) @@ -737,14 +759,15 @@ class RelayDescriptor(ServerDescriptor): # Remove the newlines from the key string & strip off the # '-----BEGIN RSA PUBLIC KEY-----' header and # '-----END RSA PUBLIC KEY-----' footer + key_as_string = ''.join(key_string.split('\n')[1:4])

# get the key representation in bytes + key_bytes = base64.b64decode(key_as_string)

return key_bytes

- class BridgeDescriptor(ServerDescriptor): """ Bridge descriptor (`bridge descriptor specification diff --git a/test/mocking.py b/test/mocking.py index 8329bc0..d1b92db 100644 --- a/test/mocking.py +++ b/test/mocking.py @@ -46,7 +46,6 @@ calling :func:`test.mocking.revert_mocking`. get_router_status_entry_micro_v3 - RouterStatusEntryMicroV3 """

- import base64 import hashlib import inspect