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most recent changes to SSL module to support non-blocking sockets properly

This commit is contained in:
Bill Janssen 2007-12-05 03:38:10 +00:00
parent a37d4c693a
commit 48dc27c040
2 changed files with 65 additions and 12 deletions
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42
Doc/library/ssl.rst
View File

@ -51,7 +51,7 @@ Functions, Constants, and Exceptions
network connection. This error is a subtype of :exc:`socket.error`, which
in turn is a subtype of :exc:`IOError`.
.. function:: wrap_socket (sock, keyfile=None, certfile=None, server_side=False, cert_reqs=CERT_NONE, ssl_version={see docs}, ca_certs=None)
.. function:: wrap_socket (sock, keyfile=None, certfile=None, server_side=False, cert_reqs=CERT_NONE, ssl_version={see docs}, ca_certs=None, do_handshake_on_connect=True, suppress_ragged_eofs=True)
Takes an instance ``sock`` of :class:`socket.socket`, and returns an instance of :class:`ssl.SSLSocket`, a subtype
of :class:`socket.socket`, which wraps the underlying socket in an SSL context.
@ -118,6 +118,18 @@ Functions, Constants, and Exceptions
`*` In some older versions of OpenSSL (for instance, 0.9.7l on OS X 10.4),
an SSLv2 client could not connect to an SSLv23 server.
The parameter ``do_handshake_on_connect`` specifies whether to do the SSL
handshake automatically after doing a :meth:`socket.connect`, or whether the
application program will call it explicitly, by invoking the :meth:`SSLSocket.do_handshake`
method. Calling :meth:`SSLSocket.do_handshake` explicitly gives the program control over
the blocking behavior of the socket I/O involved in the handshake.
The parameter ``suppress_ragged_eofs`` specifies how the :meth:`SSLSocket.read`
method should signal unexpected EOF from the other end of the connection. If specified
as :const:`True` (the default), it returns a normal EOF in response to unexpected
EOF errors raised from the underlying socket; if :const:`False`, it will raise
the exceptions back the caller.
.. function:: RAND_status()
Returns True if the SSL pseudo-random number generator has been
@ -231,15 +243,41 @@ Functions, Constants, and Exceptions
SSLSocket Objects
-----------------
.. method:: SSLSocket.read([nbytes=1024])
.. method:: SSLSocket.read(nbytes=1024, buffer=None)
Reads up to ``nbytes`` bytes from the SSL-encrypted channel and returns them.
If the ``buffer`` is specified, it will attempt to read into the buffer
the minimum of the size of the buffer and ``nbytes``, if that is specified.
If no buffer is specified, an immutable buffer is allocated and returned
with the data read from the socket.
.. method:: SSLSocket.write(data)
Writes the ``data`` to the other side of the connection, using the
SSL channel to encrypt. Returns the number of bytes written.
.. method:: SSLSocket.do_handshake()
Performs the SSL setup handshake. If the socket is non-blocking,
this method may raise :exc:`SSLError` with the value of the exception
instance's ``args[0]``
being either :const:`SSL_ERROR_WANT_READ` or
:const:`SSL_ERROR_WANT_WRITE`, and should be called again until
it stops raising those exceptions. Here's an example of how to do
that::
while True:
try:
sock.do_handshake()
break
except ssl.SSLError as err:
if err.args[0] == ssl.SSL_ERROR_WANT_READ:
select.select([sock], [], [])
elif err.args[0] == ssl.SSL_ERROR_WANT_WRITE:
select.select([], [sock], [])
else:
raise
.. method:: SSLSocket.getpeercert(binary_form=False)
If there is no certificate for the peer on the other end of the

35
Lib/ssl.py
View File

@ -126,12 +126,20 @@ class SSLSocket(socket):
keyfile, certfile,
cert_reqs, ssl_version, ca_certs)
if do_handshake_on_connect:
timeout = self.gettimeout()
if timeout == 0.0:
# non-blocking
raise ValueError("do_handshake_on_connect should not be specified for non-blocking sockets")
self.do_handshake()
except socket_error as x:
self.close()
raise x
self._base = sock
if sock and (self.fileno() != sock.fileno()):
self._base = sock
else:
self._base = None
self.keyfile = keyfile
self.certfile = certfile
self.cert_reqs = cert_reqs
@ -148,7 +156,7 @@ class SSLSocket(socket):
# raise an exception here if you wish to check for spurious closes
pass
def read(self, len=1024, buffer=None):
def read(self, len=None, buffer=None):
"""Read up to LEN bytes and return them.
Return zero-length string on EOF."""
@ -157,7 +165,7 @@ class SSLSocket(socket):
if buffer:
return self._sslobj.read(buffer, len)
else:
return self._sslobj.read(len)
return self._sslobj.read(len or 1024)
except SSLError as x:
if x.args[0] == SSL_ERROR_EOF and self.suppress_ragged_eofs:
return b''
@ -296,16 +304,18 @@ class SSLSocket(socket):
# self._closed = True
if self._base:
self._base.close()
socket._real_close(self)
socket.close(self)
def do_handshake(self):
def do_handshake(self, block=False):
"""Perform a TLS/SSL handshake."""
timeout = self.gettimeout()
try:
if timeout == 0.0 and block:
self.settimeout(None)
self._sslobj.do_handshake()
except:
self._sslobj = None
raise
finally:
self.settimeout(timeout)
def connect(self, addr):
"""Connects to remote ADDR, and then wraps the connection in
@ -339,15 +349,20 @@ class SSLSocket(socket):
addr)
def __del__(self):
self._real_close()
def wrap_socket(sock, keyfile=None, certfile=None,
server_side=False, cert_reqs=CERT_NONE,
ssl_version=PROTOCOL_SSLv23, ca_certs=None,
do_handshake_on_connect=True):
do_handshake_on_connect=True,
suppress_ragged_eofs=True):
return SSLSocket(sock=sock, keyfile=keyfile, certfile=certfile,
server_side=server_side, cert_reqs=cert_reqs,
ssl_version=ssl_version, ca_certs=ca_certs,
do_handshake_on_connect=do_handshake_on_connect)
do_handshake_on_connect=do_handshake_on_connect,
suppress_ragged_eofs=suppress_ragged_eofs)
# some utility functions