diff mercurial/sslutil.py @ 14204:5fa21960b2f4

sslutil: extracted ssl methods from httpsconnection in url.py

This makes it easier to share ssl cert validation with other http
implementations.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/sslutil.py	Wed May 04 22:08:55 2011 -0500
@@ -0,0 +1,126 @@
+# sslutil.py - SSL handling for mercurial
+#
+# Copyright 2005, 2006, 2007, 2008 Matt Mackall <[e-mail]>
+# Copyright 2006, 2007 Alexis S. L. Carvalho <[e-mail]>
+# Copyright 2006 Vadim Gelfer <[e-mail]>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+import os
+
+from mercurial import util
+from mercurial.i18n import _
+try:
+    # avoid using deprecated/broken FakeSocket in python 2.6
+    import ssl
+    ssl_wrap_socket = ssl.wrap_socket
+    CERT_REQUIRED = ssl.CERT_REQUIRED
+except ImportError:
+    CERT_REQUIRED = 2
+
+    def ssl_wrap_socket(sock, key_file, cert_file,
+                        cert_reqs=CERT_REQUIRED, ca_certs=None):
+        if ca_certs:
+            raise util.Abort(_(
+                'certificate checking requires Python 2.6'))
+
+        ssl = socket.ssl(sock, key_file, cert_file)
+        return httplib.FakeSocket(sock, ssl)
+
+def _verifycert(cert, hostname):
+    '''Verify that cert (in socket.getpeercert() format) matches hostname.
+    CRLs is not handled.
+
+    Returns error message if any problems are found and None on success.
+    '''
+    if not cert:
+        return _('no certificate received')
+    dnsname = hostname.lower()
+    def matchdnsname(certname):
+        return (certname == dnsname or
+                '.' in dnsname and certname == '*.' + dnsname.split('.', 1)[1])
+
+    san = cert.get('subjectAltName', [])
+    if san:
+        certnames = [value.lower() for key, value in san if key == 'DNS']
+        for name in certnames:
+            if matchdnsname(name):
+                return None
+        return _('certificate is for %s') % ', '.join(certnames)
+
+    # subject is only checked when subjectAltName is empty
+    for s in cert.get('subject', []):
+        key, value = s[0]
+        if key == 'commonName':
+            try:
+                # 'subject' entries are unicode
+                certname = value.lower().encode('ascii')
+            except UnicodeEncodeError:
+                return _('IDN in certificate not supported')
+            if matchdnsname(certname):
+                return None
+            return _('certificate is for %s') % certname
+    return _('no commonName or subjectAltName found in certificate')
+
+
+# CERT_REQUIRED means fetch the cert from the server all the time AND
+# validate it against the CA store provided in web.cacerts.
+#
+# We COMPLETELY ignore CERT_REQUIRED on Python <= 2.5, as it's totally
+# busted on those versions.
+
+def sslkwargs(ui, host):
+    cacerts = ui.config('web', 'cacerts')
+    hostfingerprint = ui.config('hostfingerprints', host)
+    if cacerts and not hostfingerprint:
+        cacerts = util.expandpath(cacerts)
+        if not os.path.exists(cacerts):
+            raise util.Abort(_('could not find web.cacerts: %s') % cacerts)
+        return {'ca_certs': cacerts,
+                'cert_reqs': CERT_REQUIRED,
+                }
+    return {}
+
+class validator(object):
+    def __init__(self, ui, host):
+        self.ui = ui
+        self.host = host
+
+    def __call__(self, sock):
+        host = self.host
+        cacerts = self.ui.config('web', 'cacerts')
+        hostfingerprint = self.ui.config('hostfingerprints', host)
+        if cacerts and not hostfingerprint:
+            msg = _verifycert(sock.getpeercert(), host)
+            if msg:
+                raise util.Abort(_('%s certificate error: %s '
+                                   '(use --insecure to connect '
+                                   'insecurely)') % (host, msg))
+            self.ui.debug('%s certificate successfully verified\n' % host)
+        else:
+            if getattr(sock, 'getpeercert', False):
+                peercert = sock.getpeercert(True)
+                peerfingerprint = util.sha1(peercert).hexdigest()
+                nicefingerprint = ":".join([peerfingerprint[x:x + 2]
+                    for x in xrange(0, len(peerfingerprint), 2)])
+                if hostfingerprint:
+                    if peerfingerprint.lower() != \
+                            hostfingerprint.replace(':', '').lower():
+                        raise util.Abort(_('invalid certificate for %s '
+                                           'with fingerprint %s') %
+                                         (host, nicefingerprint))
+                    self.ui.debug('%s certificate matched fingerprint %s\n' %
+                                  (host, nicefingerprint))
+                else:
+                    self.ui.warn(_('warning: %s certificate '
+                                   'with fingerprint %s not verified '
+                                   '(check hostfingerprints or web.cacerts '
+                                   'config setting)\n') %
+                                 (host, nicefingerprint))
+            else: # python 2.5 ?
+                if hostfingerprint:
+                    raise util.Abort(_('no certificate for %s with '
+                                       'configured hostfingerprint') % host)
+                self.ui.warn(_('warning: %s certificate not verified '
+                               '(check web.cacerts config setting)\n') %
+                             host)