#!/usr/bin/env python

import base64
from saml2.sigver import pre_encryption_part, make_temp, XmlsecError, \
    SigverError
from saml2.mdstore import MetadataStore
from saml2.saml import assertion_from_string, EncryptedAssertion
from saml2.samlp import response_from_string

from saml2 import sigver, extension_elements_to_elements
from saml2 import class_name
from saml2 import time_util
from saml2 import saml, samlp
from saml2 import config
from saml2.s_utils import factory, do_attribute_statement

from py.test import raises

from pathutils import full_path

SIGNED = full_path("saml_signed.xml")
UNSIGNED = full_path("saml_unsigned.xml")
SIMPLE_SAML_PHP_RESPONSE = full_path("simplesamlphp_authnresponse.xml")

PUB_KEY = full_path("test.pem")
PRIV_KEY = full_path("test.key")


def _eq(l1, l2):
    return set(l1) == set(l2)


CERT1 = """MIICsDCCAhmgAwIBAgIJAJrzqSSwmDY9MA0GCSqGSIb3DQEBBQUAMEUxCzAJBgNV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"""

CERT_SSP = """MIICizCCAfQCCQCY8tKaMc0BMjANBgkqhkiG9w0BAQUFADCBiTELMAkGA1UEBhMC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"""

from pyasn1.codec.der import decoder


def test_cert_from_instance_1():
    xml_response = open(SIGNED).read()
    response = samlp.response_from_string(xml_response)
    assertion = response.assertion[0]
    certs = sigver.cert_from_instance(assertion)
    assert len(certs) == 1
    print certs[0]
    assert certs[0] == CERT1


def test_cert_from_instance_ssp():
    xml_response = open(SIMPLE_SAML_PHP_RESPONSE).read()
    response = samlp.response_from_string(xml_response)
    assertion = response.assertion[0]
    certs = sigver.cert_from_instance(assertion)
    assert len(certs) == 1
    assert certs[0] == CERT_SSP
    der = base64.b64decode(certs[0])
    print str(decoder.decode(der)).replace('.', "\n.")
    assert decoder.decode(der)


class FakeConfig():
    """
    Configuration parameters for signature validation test cases.
    """
    xmlsec_binary = None
    crypto_backend = 'xmlsec1'
    only_use_keys_in_metadata = False
    metadata = None
    cert_file = PUB_KEY
    key_file = PRIV_KEY
    debug = False
    cert_handler_extra_class = None
    generate_cert_func = None
    generate_cert_info = False
    tmp_cert_file = None
    tmp_key_file = None
    validate_certificate = False


class TestSecurity():
    def setup_class(self):
        # This would be one way to initialize the security context :
        #
        #    conf = config.SPConfig()
        #    conf.load_file("server_conf")
        #    conf.only_use_keys_in_metadata = False
        #
        # but instead, FakeConfig() is used to really only use the minimal
        # set of parameters needed for these test cases. Other test cases
        # (TestSecurityMetadata below) excersise the SPConfig() mechanism.
        #
        conf = FakeConfig()
        self.sec = sigver.security_context(FakeConfig())

        self._assertion = factory(
            saml.Assertion,
            version="2.0",
            id="11111",
            issue_instant="2009-10-30T13:20:28Z",
            signature=sigver.pre_signature_part("11111", self.sec.my_cert, 1),
            attribute_statement=do_attribute_statement({
                ("", "", "surName"): ("Foo", ""),
                ("", "", "givenName"): ("Bar", ""),
            })
        )

    def test_verify_1(self):
        xml_response = open(SIGNED).read()
        response = self.sec.correctly_signed_response(xml_response)
        assert response

    def test_non_verify_1(self):
        """ unsigned is OK """
        xml_response = open(UNSIGNED).read()
        response = self.sec.correctly_signed_response(xml_response)
        assert response

    def test_sign_assertion(self):
        ass = self._assertion
        print ass
        sign_ass = self.sec.sign_assertion("%s" % ass, node_id=ass.id)
        #print sign_ass
        sass = saml.assertion_from_string(sign_ass)
        #print sass
        assert _eq(sass.keyswv(), ['attribute_statement', 'issue_instant',
                                   'version', 'signature', 'id'])
        assert sass.version == "2.0"
        assert sass.id == "11111"
        assert time_util.str_to_time(sass.issue_instant)

        print "Crypto version : %s" % (self.sec.crypto.version())

        item = self.sec.check_signature(sass, class_name(sass), sign_ass)

        assert isinstance(item, saml.Assertion)

    def test_multiple_signatures_assertion(self):
        ass = self._assertion
        # basic test with two of the same
        to_sign = [(ass, ass.id, ''),
                   (ass, ass.id, '')
        ]
        sign_ass = self.sec.multiple_signatures("%s" % ass, to_sign)
        sass = saml.assertion_from_string(sign_ass)
        assert _eq(sass.keyswv(), ['attribute_statement', 'issue_instant',
                                   'version', 'signature', 'id'])
        assert sass.version == "2.0"
        assert sass.id == "11111"
        assert time_util.str_to_time(sass.issue_instant)

        print "Crypto version : %s" % (self.sec.crypto.version())

        item = self.sec.check_signature(sass, class_name(sass),
                                        sign_ass, must=True)

        assert isinstance(item, saml.Assertion)

    def test_multiple_signatures_response(self):
        response = factory(samlp.Response,
                           assertion=self._assertion,
                           id="22222",
                           signature=sigver.pre_signature_part(
                               "22222", self.sec.my_cert))

        # order is important, we can't validate if the signatures are made
        # in the reverse order
        to_sign = [(self._assertion, self._assertion.id, ''),
                   (response, response.id, '')]

        s_response = self.sec.multiple_signatures("%s" % response, to_sign)
        assert s_response is not None
        response = response_from_string(s_response)

        item = self.sec.check_signature(response, class_name(response),
                                        s_response, must=True)
        assert item == response
        assert item.id == "22222"

        s_assertion = item.assertion[0]
        assert isinstance(s_assertion, saml.Assertion)
        # make sure the assertion was modified when we supposedly signed it
        assert s_assertion != self._assertion

        ci = "".join(sigver.cert_from_instance(s_assertion)[0].split())
        assert ci == self.sec.my_cert

        res = self.sec.check_signature(s_assertion, class_name(s_assertion),
                                       s_response, must=True)
        assert res == s_assertion
        assert s_assertion.id == "11111"
        assert s_assertion.version == "2.0"
        assert _eq(s_assertion.keyswv(), ['attribute_statement',
                                          'issue_instant',
                                          'version', 'signature', 'id'])

    def test_sign_response(self):
        response = factory(samlp.Response,
                           assertion=self._assertion,
                           id="22222",
                           signature=sigver.pre_signature_part("22222",
                                                               self.sec
                                                               .my_cert))

        to_sign = [(class_name(self._assertion), self._assertion.id),
                   (class_name(response), response.id)]
        s_response = sigver.signed_instance_factory(response, self.sec, to_sign)

        assert s_response is not None
        print s_response
        response = response_from_string(s_response)
        sass = response.assertion[0]

        print sass
        assert _eq(sass.keyswv(), ['attribute_statement', 'issue_instant',
                                   'version', 'signature', 'id'])
        assert sass.version == "2.0"
        assert sass.id == "11111"

        item = self.sec.check_signature(response, class_name(response),
                                        s_response)
        assert isinstance(item, samlp.Response)
        assert item.id == "22222"

    def test_sign_response_2(self):
        assertion2 = factory(saml.Assertion,
                             version="2.0",
                             id="11122",
                             issue_instant="2009-10-30T13:20:28Z",
                             signature=sigver.pre_signature_part("11122",
                                                                 self.sec
                                                                 .my_cert),
                             attribute_statement=do_attribute_statement({
                                 ("", "", "surName"): ("Fox", ""),
                                 ("", "", "givenName"): ("Bear", ""),
                             })
        )
        response = factory(samlp.Response,
                           assertion=assertion2,
                           id="22233",
                           signature=sigver.pre_signature_part("22233",
                                                               self.sec
                                                               .my_cert))

        to_sign = [(class_name(assertion2), assertion2.id),
                   (class_name(response), response.id)]

        s_response = sigver.signed_instance_factory(response, self.sec, to_sign)

        assert s_response is not None
        response2 = response_from_string(s_response)

        sass = response2.assertion[0]
        assert _eq(sass.keyswv(), ['attribute_statement', 'issue_instant',
                                   'version', 'signature', 'id'])
        assert sass.version == "2.0"
        assert sass.id == "11122"

        item = self.sec.check_signature(response2, class_name(response),
                                        s_response)

        assert isinstance(item, samlp.Response)

    def test_sign_verify(self):
        response = factory(samlp.Response,
                           assertion=self._assertion,
                           id="22233",
                           signature=sigver.pre_signature_part("22233",
                                                               self.sec
                                                               .my_cert))

        to_sign = [(class_name(self._assertion), self._assertion.id),
                   (class_name(response), response.id)]

        s_response = sigver.signed_instance_factory(response, self.sec, to_sign)

        print s_response
        res = self.sec.verify_signature("%s" % s_response,
                                        node_name=class_name(samlp.Response()))

        print res
        assert res

    def test_sign_verify_with_cert_from_instance(self):
        response = factory(samlp.Response,
                           assertion=self._assertion,
                           id="22222",
                           signature=sigver.pre_signature_part("22222",
                                                               self.sec
                                                               .my_cert))

        to_sign = [(class_name(self._assertion), self._assertion.id),
                   (class_name(response), response.id)]

        s_response = sigver.signed_instance_factory(response, self.sec, to_sign)

        response2 = response_from_string(s_response)

        ci = "".join(sigver.cert_from_instance(response2)[0].split())

        assert ci == self.sec.my_cert

        res = self.sec.verify_signature("%s" % s_response,
                                        node_name=class_name(samlp.Response()))

        assert res

        res = self.sec._check_signature(s_response, response2,
                                        class_name(response2), s_response)
        assert res == response2

    def test_sign_verify_assertion_with_cert_from_instance(self):
        assertion = factory(saml.Assertion,
                            version="2.0",
                            id="11100",
                            issue_instant="2009-10-30T13:20:28Z",
                            signature=sigver.pre_signature_part("11100",
                                                                self.sec
                                                                .my_cert),
                            attribute_statement=do_attribute_statement({
                                ("", "", "surName"): ("Fox", ""),
                                ("", "", "givenName"): ("Bear", ""),
                            })
        )

        to_sign = [(class_name(assertion), assertion.id)]
        s_assertion = sigver.signed_instance_factory(assertion, self.sec,
                                                     to_sign)
        print s_assertion
        ass = assertion_from_string(s_assertion)
        ci = "".join(sigver.cert_from_instance(ass)[0].split())
        assert ci == self.sec.my_cert

        res = self.sec.verify_signature("%s" % s_assertion,
                                        node_name=class_name(ass))
        assert res

        res = self.sec._check_signature(s_assertion, ass, class_name(ass))

        assert res

    def test_exception_sign_verify_with_cert_from_instance(self):
        assertion = factory(saml.Assertion,
                            version="2.0",
                            id="11100",
                            issue_instant="2009-10-30T13:20:28Z",
                            #signature= sigver.pre_signature_part("11100",
                            # self.sec.my_cert),
                            attribute_statement=do_attribute_statement({
                                ("", "", "surName"): ("Foo", ""),
                                ("", "", "givenName"): ("Bar", ""),
                            })
        )

        response = factory(samlp.Response,
                           assertion=assertion,
                           id="22222",
                           signature=sigver.pre_signature_part("22222",
                                                               self.sec
                                                               .my_cert))

        to_sign = [(class_name(response), response.id)]

        s_response = sigver.signed_instance_factory(response, self.sec, to_sign)

        response2 = response_from_string(s_response)
        # Change something that should make everything fail
        response2.id = "23456"
        raises(sigver.SignatureError, self.sec._check_signature,
               s_response, response2, class_name(response2))



class TestSecurityMetadata():
    def setup_class(self):
        conf = config.SPConfig()
        conf.load_file("server_conf")
        md = MetadataStore([saml, samlp], None, conf)
        md.load("local", full_path("metadata_cert.xml"))

        conf.metadata = md
        conf.only_use_keys_in_metadata = False
        self.sec = sigver.security_context(conf)

        assertion = factory(
            saml.Assertion, version="2.0", id="11111",
            issue_instant="2009-10-30T13:20:28Z",
            signature=sigver.pre_signature_part("11111", self.sec.my_cert, 1),
            attribute_statement=do_attribute_statement(
                {("", "", "surName"): ("Foo", ""),
                 ("", "", "givenName"): ("Bar", ""), })
        )


def test_xbox():
    conf = config.SPConfig()
    conf.load_file("server_conf")
    md = MetadataStore([saml, samlp], None, conf)
    md.load("local", full_path("idp_example.xml"))

    conf.metadata = md
    conf.only_use_keys_in_metadata = False
    sec = sigver.security_context(conf)

    assertion = factory(
        saml.Assertion, version="2.0", id="11111",
        issue_instant="2009-10-30T13:20:28Z",
        signature=sigver.pre_signature_part("11111", sec.my_cert, 1),
        attribute_statement=do_attribute_statement(
            {("", "", "surName"): ("Foo", ""),
             ("", "", "givenName"): ("Bar", ""), })
    )

    sigass = sec.sign_statement(assertion, class_name(assertion),
                                key_file=full_path("test.key"),
                                node_id=assertion.id)

    _ass0 = saml.assertion_from_string(sigass)

    encrypted_assertion = EncryptedAssertion()
    encrypted_assertion.add_extension_element(_ass0)

    _, pre = make_temp("%s" % pre_encryption_part(), decode=False)
    enctext = sec.crypto.encrypt(
        "%s" % encrypted_assertion, conf.cert_file, pre, "des-192",
        '/*[local-name()="EncryptedAssertion"]/*[local-name()="Assertion"]')


    decr_text = sec.decrypt(enctext)
    _seass = saml.encrypted_assertion_from_string(decr_text)
    assertions = []
    assers = extension_elements_to_elements(_seass.extension_elements,
                                            [saml, samlp])

    sign_cert_file = full_path("test.pem")

    for ass in assers:
        _ass = "%s" % ass
        #_ass = _ass.replace('xsi:nil="true" ', '')
        #assert sigass == _ass
        _txt = sec.verify_signature(_ass, sign_cert_file,
                                    node_name=class_name(assertion))
        if _txt:
            assertions.append(ass)

    print assertions


def test_xmlsec_err():
    conf = config.SPConfig()
    conf.load_file("server_conf")
    md = MetadataStore([saml, samlp], None, conf)
    md.load("local", full_path("idp_example.xml"))

    conf.metadata = md
    conf.only_use_keys_in_metadata = False
    sec = sigver.security_context(conf)

    assertion = factory(
        saml.Assertion, version="2.0", id="11111",
        issue_instant="2009-10-30T13:20:28Z",
        signature=sigver.pre_signature_part("11111", sec.my_cert, 1),
        attribute_statement=do_attribute_statement(
            {("", "", "surName"): ("Foo", ""),
             ("", "", "givenName"): ("Bar", ""), })
    )

    try:
        sec.sign_statement(assertion, class_name(assertion),
                           key_file=full_path("tes.key"),
                           node_id=assertion.id)
    except (XmlsecError, SigverError) as err:  # should throw an exception
        pass
    else:
        assert False


if __name__ == "__main__":
    # t = TestSecurity()
    # t.setup_class()
    # t.test_non_verify_2()

    test_xmlsec_err()
