| import os |
| import socket |
| import atexit |
| import re |
| import functools |
| |
| from setuptools.extern.six.moves import urllib, http_client, map, filter |
| |
| from pkg_resources import ResolutionError, ExtractionError |
| |
| try: |
| import ssl |
| except ImportError: |
| ssl = None |
| |
| __all__ = [ |
| 'VerifyingHTTPSHandler', 'find_ca_bundle', 'is_available', 'cert_paths', |
| 'opener_for' |
| ] |
| |
| cert_paths = """ |
| /etc/pki/tls/certs/ca-bundle.crt |
| /etc/ssl/certs/ca-certificates.crt |
| /usr/share/ssl/certs/ca-bundle.crt |
| /usr/local/share/certs/ca-root.crt |
| /etc/ssl/cert.pem |
| /System/Library/OpenSSL/certs/cert.pem |
| /usr/local/share/certs/ca-root-nss.crt |
| /etc/ssl/ca-bundle.pem |
| """.strip().split() |
| |
| try: |
| HTTPSHandler = urllib.request.HTTPSHandler |
| HTTPSConnection = http_client.HTTPSConnection |
| except AttributeError: |
| HTTPSHandler = HTTPSConnection = object |
| |
| is_available = ssl is not None and object not in ( |
| HTTPSHandler, HTTPSConnection) |
| |
| |
| try: |
| from ssl import CertificateError, match_hostname |
| except ImportError: |
| try: |
| from backports.ssl_match_hostname import CertificateError |
| from backports.ssl_match_hostname import match_hostname |
| except ImportError: |
| CertificateError = None |
| match_hostname = None |
| |
| if not CertificateError: |
| |
| class CertificateError(ValueError): |
| pass |
| |
| |
| if not match_hostname: |
| |
| def _dnsname_match(dn, hostname, max_wildcards=1): |
| """Matching according to RFC 6125, section 6.4.3 |
| |
| https://tools.ietf.org/html/rfc6125#section-6.4.3 |
| """ |
| pats = [] |
| if not dn: |
| return False |
| |
| # Ported from python3-syntax: |
| # leftmost, *remainder = dn.split(r'.') |
| parts = dn.split(r'.') |
| leftmost = parts[0] |
| remainder = parts[1:] |
| |
| wildcards = leftmost.count('*') |
| if wildcards > max_wildcards: |
| # Issue #17980: avoid denials of service by refusing more |
| # than one wildcard per fragment. A survey of established |
| # policy among SSL implementations showed it to be a |
| # reasonable choice. |
| raise CertificateError( |
| "too many wildcards in certificate DNS name: " + repr(dn)) |
| |
| # speed up common case w/o wildcards |
| if not wildcards: |
| return dn.lower() == hostname.lower() |
| |
| # RFC 6125, section 6.4.3, subitem 1. |
| # The client SHOULD NOT attempt to match a |
| # presented identifier in which the wildcard |
| # character comprises a label other than the |
| # left-most label. |
| if leftmost == '*': |
| # When '*' is a fragment by itself, it matches a non-empty dotless |
| # fragment. |
| pats.append('[^.]+') |
| elif leftmost.startswith('xn--') or hostname.startswith('xn--'): |
| # RFC 6125, section 6.4.3, subitem 3. |
| # The client SHOULD NOT attempt to match a presented identifier |
| # where the wildcard character is embedded within an A-label or |
| # U-label of an internationalized domain name. |
| pats.append(re.escape(leftmost)) |
| else: |
| # Otherwise, '*' matches any dotless string, e.g. www* |
| pats.append(re.escape(leftmost).replace(r'\*', '[^.]*')) |
| |
| # add the remaining fragments, ignore any wildcards |
| for frag in remainder: |
| pats.append(re.escape(frag)) |
| |
| pat = re.compile(r'\A' + r'\.'.join(pats) + r'\Z', re.IGNORECASE) |
| return pat.match(hostname) |
| |
| def match_hostname(cert, hostname): |
| """Verify that *cert* (in decoded format as returned by |
| SSLSocket.getpeercert()) matches the *hostname*. RFC 2818 and RFC 6125 |
| rules are followed, but IP addresses are not accepted for *hostname*. |
| |
| CertificateError is raised on failure. On success, the function |
| returns nothing. |
| """ |
| if not cert: |
| raise ValueError("empty or no certificate") |
| dnsnames = [] |
| san = cert.get('subjectAltName', ()) |
| for key, value in san: |
| if key == 'DNS': |
| if _dnsname_match(value, hostname): |
| return |
| dnsnames.append(value) |
| if not dnsnames: |
| # The subject is only checked when there is no dNSName entry |
| # in subjectAltName |
| for sub in cert.get('subject', ()): |
| for key, value in sub: |
| # XXX according to RFC 2818, the most specific Common Name |
| # must be used. |
| if key == 'commonName': |
| if _dnsname_match(value, hostname): |
| return |
| dnsnames.append(value) |
| if len(dnsnames) > 1: |
| raise CertificateError( |
| "hostname %r doesn't match either of %s" |
| % (hostname, ', '.join(map(repr, dnsnames)))) |
| elif len(dnsnames) == 1: |
| raise CertificateError( |
| "hostname %r doesn't match %r" |
| % (hostname, dnsnames[0])) |
| else: |
| raise CertificateError( |
| "no appropriate commonName or " |
| "subjectAltName fields were found") |
| |
| |
| class VerifyingHTTPSHandler(HTTPSHandler): |
| """Simple verifying handler: no auth, subclasses, timeouts, etc.""" |
| |
| def __init__(self, ca_bundle): |
| self.ca_bundle = ca_bundle |
| HTTPSHandler.__init__(self) |
| |
| def https_open(self, req): |
| return self.do_open( |
| lambda host, **kw: VerifyingHTTPSConn(host, self.ca_bundle, **kw), |
| req |
| ) |
| |
| |
| class VerifyingHTTPSConn(HTTPSConnection): |
| """Simple verifying connection: no auth, subclasses, timeouts, etc.""" |
| |
| def __init__(self, host, ca_bundle, **kw): |
| HTTPSConnection.__init__(self, host, **kw) |
| self.ca_bundle = ca_bundle |
| |
| def connect(self): |
| sock = socket.create_connection( |
| (self.host, self.port), getattr(self, 'source_address', None) |
| ) |
| |
| # Handle the socket if a (proxy) tunnel is present |
| if hasattr(self, '_tunnel') and getattr(self, '_tunnel_host', None): |
| self.sock = sock |
| self._tunnel() |
| # http://bugs.python.org/issue7776: Python>=3.4.1 and >=2.7.7 |
| # change self.host to mean the proxy server host when tunneling is |
| # being used. Adapt, since we are interested in the destination |
| # host for the match_hostname() comparison. |
| actual_host = self._tunnel_host |
| else: |
| actual_host = self.host |
| |
| if hasattr(ssl, 'create_default_context'): |
| ctx = ssl.create_default_context(cafile=self.ca_bundle) |
| self.sock = ctx.wrap_socket(sock, server_hostname=actual_host) |
| else: |
| # This is for python < 2.7.9 and < 3.4? |
| self.sock = ssl.wrap_socket( |
| sock, cert_reqs=ssl.CERT_REQUIRED, ca_certs=self.ca_bundle |
| ) |
| try: |
| match_hostname(self.sock.getpeercert(), actual_host) |
| except CertificateError: |
| self.sock.shutdown(socket.SHUT_RDWR) |
| self.sock.close() |
| raise |
| |
| |
| def opener_for(ca_bundle=None): |
| """Get a urlopen() replacement that uses ca_bundle for verification""" |
| return urllib.request.build_opener( |
| VerifyingHTTPSHandler(ca_bundle or find_ca_bundle()) |
| ).open |
| |
| |
| # from jaraco.functools |
| def once(func): |
| @functools.wraps(func) |
| def wrapper(*args, **kwargs): |
| if not hasattr(func, 'always_returns'): |
| func.always_returns = func(*args, **kwargs) |
| return func.always_returns |
| return wrapper |
| |
| |
| @once |
| def get_win_certfile(): |
| try: |
| import wincertstore |
| except ImportError: |
| return None |
| |
| class CertFile(wincertstore.CertFile): |
| def __init__(self): |
| super(CertFile, self).__init__() |
| atexit.register(self.close) |
| |
| def close(self): |
| try: |
| super(CertFile, self).close() |
| except OSError: |
| pass |
| |
| _wincerts = CertFile() |
| _wincerts.addstore('CA') |
| _wincerts.addstore('ROOT') |
| return _wincerts.name |
| |
| |
| def find_ca_bundle(): |
| """Return an existing CA bundle path, or None""" |
| extant_cert_paths = filter(os.path.isfile, cert_paths) |
| return ( |
| get_win_certfile() |
| or next(extant_cert_paths, None) |
| or _certifi_where() |
| ) |
| |
| |
| def _certifi_where(): |
| try: |
| return __import__('certifi').where() |
| except (ImportError, ResolutionError, ExtractionError): |
| pass |
