Add support for asyncore server-side SSL support. This requires

adding the 'makefile' method to ssl.SSLSocket, and importing the
requisite fakefile class from socket.py, and making the appropriate
changes to it to make it use the SSL connection.

Added sample HTTPS server to test_ssl.py, and test that uses it.

Change SSL tests to use https://svn.python.org/, instead of
www.sf.net and pop.gmail.com.

Added utility function to ssl module, get_server_certificate,
to wrap up the several things to be done to pull a certificate
from a remote server.
This commit is contained in:
Bill Janssen 2007-09-16 22:06:00 +00:00
parent 7e84c7f4b5
commit 296a59d3be
5 changed files with 616 additions and 188 deletions

View file

@ -55,7 +55,7 @@ PROTOCOL_SSLv23
PROTOCOL_TLSv1
"""
import os, sys
import os, sys, textwrap
import _ssl # if we can't import it, let the error propagate
@ -76,19 +76,7 @@ from _ssl import \
from socket import socket
from socket import getnameinfo as _getnameinfo
def get_protocol_name (protocol_code):
if protocol_code == PROTOCOL_TLSv1:
return "TLSv1"
elif protocol_code == PROTOCOL_SSLv23:
return "SSLv23"
elif protocol_code == PROTOCOL_SSLv2:
return "SSLv2"
elif protocol_code == PROTOCOL_SSLv3:
return "SSLv3"
else:
return "<unknown>"
import base64 # for DER-to-PEM translation
class SSLSocket (socket):
@ -193,21 +181,12 @@ class SSLSocket (socket):
else:
return socket.recv_from(self, addr, buflen, flags)
def ssl_shutdown(self):
"""Shuts down the SSL channel over this socket (if active),
without closing the socket connection."""
if self._sslobj:
self._sslobj.shutdown()
self._sslobj = None
def shutdown(self, how):
self.ssl_shutdown()
self._sslobj = None
socket.shutdown(self, how)
def close(self):
self.ssl_shutdown()
self._sslobj = None
socket.close(self)
def connect(self, addr):
@ -236,6 +215,248 @@ class SSLSocket (socket):
self.ca_certs), addr)
def makefile(self, mode='r', bufsize=-1):
"""Ouch. Need to make and return a file-like object that
works with the SSL connection."""
if self._sslobj:
return SSLFileStream(self._sslobj, mode, bufsize)
else:
return socket.makefile(self, mode, bufsize)
class SSLFileStream:
"""A class to simulate a file stream on top of a socket.
Most of this is just lifted from the socket module, and
adjusted to work with an SSL stream instead of a socket."""
default_bufsize = 8192
name = "<SSL stream>"
__slots__ = ["mode", "bufsize", "softspace",
# "closed" is a property, see below
"_sslobj", "_rbufsize", "_wbufsize", "_rbuf", "_wbuf",
"_close", "_fileno"]
def __init__(self, sslobj, mode='rb', bufsize=-1, close=False):
self._sslobj = sslobj
self.mode = mode # Not actually used in this version
if bufsize < 0:
bufsize = self.default_bufsize
self.bufsize = bufsize
self.softspace = False
if bufsize == 0:
self._rbufsize = 1
elif bufsize == 1:
self._rbufsize = self.default_bufsize
else:
self._rbufsize = bufsize
self._wbufsize = bufsize
self._rbuf = "" # A string
self._wbuf = [] # A list of strings
self._close = close
self._fileno = -1
def _getclosed(self):
return self._sslobj is None
closed = property(_getclosed, doc="True if the file is closed")
def fileno(self):
return self._fileno
def close(self):
try:
if self._sslobj:
self.flush()
finally:
if self._close and self._sslobj:
self._sslobj.close()
self._sslobj = None
def __del__(self):
try:
self.close()
except:
# close() may fail if __init__ didn't complete
pass
def flush(self):
if self._wbuf:
buffer = "".join(self._wbuf)
self._wbuf = []
count = 0
while (count < len(buffer)):
written = self._sslobj.write(buffer)
count += written
buffer = buffer[written:]
def write(self, data):
data = str(data) # XXX Should really reject non-string non-buffers
if not data:
return
self._wbuf.append(data)
if (self._wbufsize == 0 or
self._wbufsize == 1 and '\n' in data or
self._get_wbuf_len() >= self._wbufsize):
self.flush()
def writelines(self, list):
# XXX We could do better here for very long lists
# XXX Should really reject non-string non-buffers
self._wbuf.extend(filter(None, map(str, list)))
if (self._wbufsize <= 1 or
self._get_wbuf_len() >= self._wbufsize):
self.flush()
def _get_wbuf_len(self):
buf_len = 0
for x in self._wbuf:
buf_len += len(x)
return buf_len
def read(self, size=-1):
data = self._rbuf
if size < 0:
# Read until EOF
buffers = []
if data:
buffers.append(data)
self._rbuf = ""
if self._rbufsize <= 1:
recv_size = self.default_bufsize
else:
recv_size = self._rbufsize
while True:
data = self._sslobj.read(recv_size)
if not data:
break
buffers.append(data)
return "".join(buffers)
else:
# Read until size bytes or EOF seen, whichever comes first
buf_len = len(data)
if buf_len >= size:
self._rbuf = data[size:]
return data[:size]
buffers = []
if data:
buffers.append(data)
self._rbuf = ""
while True:
left = size - buf_len
recv_size = max(self._rbufsize, left)
data = self._sslobj.read(recv_size)
if not data:
break
buffers.append(data)
n = len(data)
if n >= left:
self._rbuf = data[left:]
buffers[-1] = data[:left]
break
buf_len += n
return "".join(buffers)
def readline(self, size=-1):
data = self._rbuf
if size < 0:
# Read until \n or EOF, whichever comes first
if self._rbufsize <= 1:
# Speed up unbuffered case
assert data == ""
buffers = []
while data != "\n":
data = self._sslobj.read(1)
if not data:
break
buffers.append(data)
return "".join(buffers)
nl = data.find('\n')
if nl >= 0:
nl += 1
self._rbuf = data[nl:]
return data[:nl]
buffers = []
if data:
buffers.append(data)
self._rbuf = ""
while True:
data = self._sslobj.read(self._rbufsize)
if not data:
break
buffers.append(data)
nl = data.find('\n')
if nl >= 0:
nl += 1
self._rbuf = data[nl:]
buffers[-1] = data[:nl]
break
return "".join(buffers)
else:
# Read until size bytes or \n or EOF seen, whichever comes first
nl = data.find('\n', 0, size)
if nl >= 0:
nl += 1
self._rbuf = data[nl:]
return data[:nl]
buf_len = len(data)
if buf_len >= size:
self._rbuf = data[size:]
return data[:size]
buffers = []
if data:
buffers.append(data)
self._rbuf = ""
while True:
data = self._sslobj.read(self._rbufsize)
if not data:
break
buffers.append(data)
left = size - buf_len
nl = data.find('\n', 0, left)
if nl >= 0:
nl += 1
self._rbuf = data[nl:]
buffers[-1] = data[:nl]
break
n = len(data)
if n >= left:
self._rbuf = data[left:]
buffers[-1] = data[:left]
break
buf_len += n
return "".join(buffers)
def readlines(self, sizehint=0):
total = 0
list = []
while True:
line = self.readline()
if not line:
break
list.append(line)
total += len(line)
if sizehint and total >= sizehint:
break
return list
# Iterator protocols
def __iter__(self):
return self
def next(self):
line = self.readline()
if not line:
raise StopIteration
return line
def wrap_socket(sock, keyfile=None, certfile=None,
server_side=False, cert_reqs=CERT_NONE,
ssl_version=PROTOCOL_SSLv23, ca_certs=None):
@ -255,6 +476,71 @@ def cert_time_to_seconds(cert_time):
import time
return time.mktime(time.strptime(cert_time, "%b %d %H:%M:%S %Y GMT"))
PEM_HEADER = "-----BEGIN CERTIFICATE-----"
PEM_FOOTER = "-----END CERTIFICATE-----"
def DER_cert_to_PEM_cert(der_cert_bytes):
"""Takes a certificate in binary DER format and returns the
PEM version of it as a string."""
if hasattr(base64, 'standard_b64encode'):
# preferred because older API gets line-length wrong
f = base64.standard_b64encode(der_cert_bytes)
return (PEM_HEADER + '\n' +
textwrap.fill(f, 64) +
PEM_FOOTER + '\n')
else:
return (PEM_HEADER + '\n' +
base64.encodestring(der_cert_bytes) +
PEM_FOOTER + '\n')
def PEM_cert_to_DER_cert(pem_cert_string):
"""Takes a certificate in ASCII PEM format and returns the
DER-encoded version of it as a byte sequence"""
if not pem_cert_string.startswith(PEM_HEADER):
raise ValueError("Invalid PEM encoding; must start with %s"
% PEM_HEADER)
if not pem_cert_string.strip().endswith(PEM_FOOTER):
raise ValueError("Invalid PEM encoding; must end with %s"
% PEM_FOOTER)
d = pem_cert_string.strip()[len(PEM_HEADER):-len(PEM_FOOTER)]
return base64.decodestring(d)
def get_server_certificate (addr, ssl_version=PROTOCOL_SSLv3, ca_certs=None):
"""Retrieve the certificate from the server at the specified address,
and return it as a PEM-encoded string.
If 'ca_certs' is specified, validate the server cert against it.
If 'ssl_version' is specified, use it in the connection attempt."""
host, port = addr
if (ca_certs is not None):
cert_reqs = CERT_REQUIRED
else:
cert_reqs = CERT_NONE
s = wrap_socket(socket(), ssl_version=ssl_version,
cert_reqs=cert_reqs, ca_certs=ca_certs)
s.connect(addr)
dercert = s.getpeercert(True)
s.close()
return DER_cert_to_PEM_cert(dercert)
def get_protocol_name (protocol_code):
if protocol_code == PROTOCOL_TLSv1:
return "TLSv1"
elif protocol_code == PROTOCOL_SSLv23:
return "SSLv23"
elif protocol_code == PROTOCOL_SSLv2:
return "SSLv2"
elif protocol_code == PROTOCOL_SSLv3:
return "SSLv3"
else:
return "<unknown>"
# a replacement for the old socket.ssl function
def sslwrap_simple (sock, keyfile=None, certfile=None):