SSL cert validation

#!/usr/bin/env python3.3
import os
import ssl
import socket

FILE = os.path.abspath(__file__)
HERE = os.path.dirname(FILE)
ADDRESS = ("apple.com", 443)
CACERT_ADDRESS = ("www.cacert.org", 443)


def get_server_certificate(addr, cafile=None, capath=None):
    ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv3)
    ctx.verify_mode = ssl.CERT_REQUIRED
    if cafile is None and capath is None:
        ctx.set_default_verify_paths()
    else:
        ctx.load_verify_locations(cafile=cafile, capath=capath)
    with socket.create_connection(addr) as conn:
        with ctx.wrap_socket(conn) as sconn:
            return sconn.getpeercert()


def test():
    print("Check with default verify paths")
    try:
        get_server_certificate(ADDRESS)
    except ssl.SSLError as e:
        print("  FAIL -- no default certs available?")
        print("  {}".format(e))
    else:
        print("  PASS")

    print("Check verficiation with CACert as only root CA")
    try:
        get_server_certificate(ADDRESS, FILE, HERE)
    except ssl.SSLError as e:
        print("  PASS -- check failure expected")
        print("  {}".format(e))
    else:
        print("  BUG -- check should have failed")

    print("Check www.cacert.org:443 with CACert root CA")
    try:
        get_server_certificate(CACERT_ADDRESS, FILE, HERE)
    except ssl.SSLError as e:
        print("  FAIL")
        print("  {}".format(e))
    else:
        print("  PASS")


if __name__ == "__main__":
    test()


"""http://www.cacert.org/certs/root.crt

-----BEGIN CERTIFICATE-----
MIIHPTCCBSWgAwIBAgIBADANBgkqhkiG9w0BAQQFADB5MRAwDgYDVQQKEwdSb290
IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNB
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omTxJBzcoTWcFbLUvFUufQb1nA5V9FrWk9p2rSVzTMVD
-----END CERTIFICATE-----

"""