added certificate pinning descriptions to README

Linux/README.md

@@ -34,6 +34,22 @@ than per Linux user for Chrome), you need to do this for every profile under `~/
             ./revoke-china-certs.sh extended $HOME/.mozilla/firefox/$profile
         done
 
+## Certificate Pinning Test
+
+Certificate pinning test is implemented in `certificate_pinning_test.py`.
+Use it as:
+
+    ./certificate_pinning_test.py
+
+This should reveal any HTTPS Man-In-The-Middle devices that may eavesdrop
+your connection (with Google), including but not limited to a transparent
+proxy.
+
+The pinning test uses signatures extracted from Android.
+
+(This is experimental. If you do encounter an error, please file an issue
+with the certificate you get.)
+
 ## Notes
 
 Deselecting a CA by `dpkg-reconfigure ca-certificates` does NOT affect any NSS-based applications.

Linux/certificate_pinning_test.py

+#!/usr/local/env python
+import ssl
+import M2Crypto
+import hashlib
+import json
+import base64
+import socket
+from socket import *
+from tlslite.api import *
+
+tests = [
+    #{
+    #'domain':'www.126.com',
+    #'pkey':['dc4fa0d8fb3b6aeef24aa4f378b9c1c63fb538e5d21c4473691ec9c1878c632f08b83541415cad27da8bb2c1743939e0277738fd96b8a055e23cd79903986566', 'd7e4ef3f14da0bdc88c7917274961992325c66363b76288159e8a440ef864fcc16558a7481d98240b25c1206310c959a124cebd8c06baf5dfcd79c266f389428']},
+    {
+    'domain':'www.alipay.com',
+    'pkey':['18f1d378969f462c3150a9c66d353e84df8ef00efbbd589fa35fdd04cf3e46425f7b12a205b3d5cb8b2e708ae650d34e2c9c6b4b8c02d950805ddab77c901767']},
+]
+
+class SocksCannotConnect(socket.error):
+    pass
+
+def get_pins(fname='pins.txt'):
+    f = open(fname, 'r')
+    pins = f.readlines()
+    f.close()
+    generated = []
+    for pin in pins:
+        domain = pin.split('=')[0]
+        hashes = pin.strip().rsplit('|')[-1].split(',')
+        if '*.' in domain:
+            # Try different replace strategy
+            generated.append({'domain': domain.replace('*.', '0.'), 'pkey': hashes})
+            generated.append({'domain': domain.replace('*.', 'www.'), 'pkey': hashes})
+            generated.append({'domain': domain.replace('*.', ''), 'pkey': hashes})
+        else:
+            generated.append({'domain': domain, 'pkey': hashes})
+    return generated
+
+def get_last_issuer_cert_der(conn):
+    sock = socket.socket(AF_INET, SOCK_STREAM)
+    try:
+        sock.connect( conn )
+    except:
+        raise SocksCannotConnect
+    connection = TLSConnection(sock)
+    connection.handshakeClientCert()
+
+    x=connection.session.serverCertChain   # X509CertChain
+    y=x.x509List[1]
+    return y.bytes
+
+def test_site(assertion):
+    port = assertion.get('port', 443)
+    conn = (assertion['domain'], port)
+    try:
+        cert = get_last_issuer_cert_der( conn )
+    except socket.error:
+        # If cannot connect even without TLS, let it go
+        print "Error connecting to", conn, "but no certificate errors involved."
+        return
+    except TLSRemoteAlert as alert:
+        if not assertion['pkey']:
+            # Expected to get this error
+            return
+        raise RuntimeError(assertion, None)
+    x509 = M2Crypto.X509.load_cert_der_string(cert)
+    pubkey = x509.get_pubkey().as_der()
+    digest = hashlib.sha512(pubkey).hexdigest()
+    if not digest in assertion['pkey']:
+        raise RuntimeError(assertion, digest)
+
+def main():
+    global tests
+    tests += get_pins()
+    try:
+        for assertion in tests:
+            test_site(assertion)
+    except RuntimeError as e:
+        print "ERROR: Certificate error!"
+        recv_cert = e.args[1] or '<- Certificate from invalid issuer ->'
+        msg = "Expected public key hash of %s for %s, got %s" % \
+            (e.args[0]['pkey'], e.args[0]['domain'], recv_cert)
+        print msg
+        
+
+if __name__ == "__main__":
+    main()