# ===================================================================
#
# Copyright (c) 2014, Legrandin <helderijs@gmail.com>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in
#    the documentation and/or other materials provided with the
#    distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
# COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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# ===================================================================

import json
import unittest
from binascii import unhexlify

from Cryptodome.Util.py3compat import b, bchr
from Cryptodome.Util.number import bytes_to_long
from Cryptodome.Util.strxor import strxor
from Cryptodome.SelfTest.st_common import list_test_cases
from Cryptodome.SelfTest.loader import load_tests

from Cryptodome.Hash import SHA1, SHA224, SHA256, SHA384, SHA512
from Cryptodome.PublicKey import RSA
from Cryptodome.Signature import pss
from Cryptodome.Signature import PKCS1_PSS

from Cryptodome.Signature.pss import MGF1

from Cryptodome.Util._file_system import pycryptodome_filename


def load_hash_by_name(hash_name):
    return __import__("Cryptodome.Hash." + hash_name, globals(), locals(), ["new"])


class PRNG(object):

    def __init__(self, stream):
        self.stream = stream
        self.idx = 0

    def __call__(self, rnd_size):
        result = self.stream[self.idx:self.idx + rnd_size]
        self.idx += rnd_size
        return result


class PSS_Tests(unittest.TestCase):

    rsa_key = b'-----BEGIN RSA PRIVATE KEY-----\nMIIEowIBAAKCAQEAsvI34FgiTK8+txBvmooNGpNwk23YTU51dwNZi5yha3W4lA/Q\nvcZrDalkmD7ekWQwnduxVKa6pRSI13KBgeUOIqJoGXSWhntEtY3FEwvWOHW5AE7Q\njUzTzCiYT6TVaCcpa/7YLai+p6ai2g5f5Zfh4jSawa9uYeuggFygQq4IVW796MgV\nyqxYMM/arEj+/sKz3Viua9Rp9fFosertCYCX4DUTgW0mX9bwEnEOgjSI3pLOPXz1\n8vx+DRZS5wMCmwCUa0sKonLn3cAUPq+sGix7+eo7T0Z12MU8ud7IYVX/75r3cXiF\nPaYE2q8Le0kgOApIXbb+x74x0rNgyIh1yGygkwIDAQABAoIBABz4t1A0pLT6qHI2\nEIOaNz3mwhK0dZEqkz0GB1Dhtoax5ATgvKCFB98J3lYB08IBURe1snOsnMpOVUtg\naBRSM+QqnCUG6bnzKjAkuFP5liDE+oNQv1YpKp9CsUovuzdmI8Au3ewihl+ZTIN2\nUVNYMEOR1b5m+z2SSwWNOYsiJwpBrT7zkpdlDyjat7FiiPhMMIMXjhQFVxURMIcB\njUBtPzGvV/PG90cVDWi1wRGeeP1dDqti/jsnvykQ15KW1MqGrpeNKRmDdTy/Ucl1\nWIoYklKw3U456lgZ/rDTDB818+Tlnk35z4yF7d5ANPM8CKfqOPcnO1BCKVFzf4eq\n54wvUtkCgYEA1Zv2lp06l7rXMsvNtyYQjbFChezRDRnPwZmN4NCdRtTgGG1G0Ryd\nYz6WWoPGqZp0b4LAaaHd3W2GTcpXF8WXMKfMX1W+tMAxMozfsXRKMcHoypwuS5wT\nfJRXJCG4pvd57AB0iVUEJW2we+uGKU5Zxcx//id2nXGCpoRyViIplQsCgYEA1nVC\neHupHChht0Fh4N09cGqZHZzuwXjOUMzR3Vsfz+4WzVS3NvIgN4g5YgmQFOeKwo5y\niRq5yvubcNdFvf85eHWClg0zPAyxJCVUWigCrrOanGEhJo6re4idJvNVzu4Ucg0v\n6B3SJ1HsCda+ZSNz24bSyqRep8A+RoAaoVSFx5kCgYEAn3RvXPs9s+obnqWYiPF3\nRe5etE6Vt2vfNKwFxx6zaR6bsmBQjuUHcABWiHb6I71S0bMPI0tbrWGG8ibrYKl1\nNTLtUvVVCOS3VP7oNTWT9RTFTAnOXU7DFSo+6o/poWn3r36ff6zhDXeWWMr2OXtt\ndEQ1/2lCGEGVv+v61eVmmQUCgYABFHITPTwqwiFL1O5zPWnzyPWgaovhOYSAb6eW\n38CXQXGn8wdBJZL39J2lWrr4//l45VK6UgIhfYbY2JynSkO10ZGow8RARygVMILu\nOUlaK9lZdDvAf/NpGdUAvzTtZ9F+iYZ2OsA2JnlzyzsGM1l//3vMPWukmJk3ral0\nqoJJ8QKBgGRG3eVHnIegBbFVuMDp2NTcfuSuDVUQ1fGAwtPiFa8u81IodJnMk2pq\niXu2+0ytNA/M+SVrAnE2AgIzcaJbtr0p2srkuVM7KMWnG1vWFNjtXN8fAhf/joOv\nD+NmPL/N4uE57e40tbiU/H7KdyZaDt+5QiTmdhuyAe6CBjKsF2jy\n-----END RSA PRIVATE KEY-----'
    msg = b'AAA'
    tag = b'\x00[c5\xd8\xb0\x8b!D\x81\x83\x07\xc0\xdd\xb9\xb4\xb2`\x92\xe7\x02\xf1\xe1P\xea\xc3\xf0\xe3>\xddX5\xdd\x8e\xc5\x89\xef\xf3\xc2\xdc\xfeP\x02\x7f\x12+\xc9\xaf\xbb\xec\xfe\xb0\xa5\xb9\x08\x11P\x8fL\xee5\x9b\xb0k{=_\xd2\x14\xfb\x01R\xb7\xfe\x14}b\x03\x8d5Y\x89~}\xfc\xf2l\xd01-\xbd\xeb\x11\xcdV\x11\xe9l\x19k/o5\xa2\x0f\x15\xe7Q$\t=\xec\x1dAB\x19\xa5P\x9a\xaf\xa3G\x86"\xd6~\xf0<p5\x00\x86\xe0\xf3\x99\xc7+\xcfc,\\\x13)v\xcd\xff\x08o\x90\xc5\xd1\xca\x869\xf45\x1e\xfd\xa2\xf1n\xa3\xa6e\xc5\x11Q\xe4@\xbd\x17\x83x\xc9\x9b\xb5\xc7\xea\x03U\x9b\xa0\xccC\x17\xc9T\x86/\x05\x1c\xc7\x95hC\xf9b1\xbb\x05\xc3\xf0\x9a>j\xfcqkbs\x13\x84b\xe4\xbdm(\xed`\xa4F\xfb\x8f.\xe1\x8c)/_\x9eS\x98\xa4v\xb8\xdc\xfe\xf7/D\x18\x19\xb3T\x97:\xe2\x96s\xe8<\xa2\xb4\xb9\xf8/'

    def test_positive_1(self):
        key = RSA.import_key(self.rsa_key)
        h = SHA256.new(self.msg)
        verifier = pss.new(key)
        verifier.verify(h, self.tag)

    def test_negative_1(self):
        key = RSA.import_key(self.rsa_key)
        h = SHA256.new(self.msg + b'A')
        verifier = pss.new(key)
        tag = bytearray(self.tag)
        self.assertRaises(ValueError, verifier.verify, h, tag)

    def test_negative_2(self):
        key = RSA.import_key(self.rsa_key)
        h = SHA256.new(self.msg)
        verifier = pss.new(key, salt_bytes=1000)
        tag = bytearray(self.tag)
        self.assertRaises(ValueError, verifier.verify, h, tag)


class FIPS_PKCS1_Verify_Tests(unittest.TestCase):

    def shortDescription(self):
        return "FIPS PKCS1 Tests (Verify)"

    def verify_positive(self, hashmod, message, public_key, salt, signature):
        prng = PRNG(salt)
        hashed = hashmod.new(message)
        verifier = pss.new(public_key, salt_bytes=len(salt), rand_func=prng)
        verifier.verify(hashed, signature)

    def verify_negative(self, hashmod, message, public_key, salt, signature):
        prng = PRNG(salt)
        hashed = hashmod.new(message)
        verifier = pss.new(public_key, salt_bytes=len(salt), rand_func=prng)
        self.assertRaises(ValueError, verifier.verify, hashed, signature)

    def test_can_sign(self):
        test_public_key = RSA.generate(1024).publickey()
        verifier = pss.new(test_public_key)
        self.assertEqual(verifier.can_sign(), False)


class FIPS_PKCS1_Verify_Tests_KAT(unittest.TestCase):
    pass


test_vectors_verify = load_tests(("Cryptodome", "SelfTest", "Signature", "test_vectors", "PKCS1-PSS"),
                                 "SigVerPSS_186-3.rsp",
                                 "Signature Verification 186-3",
                                 { 'shaalg' : lambda x: x,
                                   'result' : lambda x: x })


for count, tv in enumerate(test_vectors_verify):
    if isinstance(tv, str):
        continue
    if hasattr(tv, "n"):
        modulus = tv.n
        continue
    if hasattr(tv, "p"):
        continue

    hash_module = load_hash_by_name(tv.shaalg.upper())
    hash_obj = hash_module.new(tv.msg)
    public_key = RSA.construct([bytes_to_long(x) for x in (modulus, tv.e)]) # type: ignore
    if tv.saltval != b("\x00"):
        prng = PRNG(tv.saltval)
        verifier = pss.new(public_key, salt_bytes=len(tv.saltval), rand_func=prng)
    else:
        verifier = pss.new(public_key, salt_bytes=0)

    def positive_test(self, hash_obj=hash_obj, verifier=verifier, signature=tv.s):
        verifier.verify(hash_obj, signature)

    def negative_test(self, hash_obj=hash_obj, verifier=verifier, signature=tv.s):
        self.assertRaises(ValueError, verifier.verify, hash_obj, signature)

    if tv.result == 'p':
        setattr(FIPS_PKCS1_Verify_Tests_KAT, "test_positive_%d" % count, positive_test)
    else:
        setattr(FIPS_PKCS1_Verify_Tests_KAT, "test_negative_%d" % count, negative_test)


class FIPS_PKCS1_Sign_Tests(unittest.TestCase):

    def shortDescription(self):
        return "FIPS PKCS1 Tests (Sign)"

    def test_can_sign(self):
        test_private_key = RSA.generate(1024)
        signer = pss.new(test_private_key)
        self.assertEqual(signer.can_sign(), True)


class FIPS_PKCS1_Sign_Tests_KAT(unittest.TestCase):
    pass


test_vectors_sign  = load_tests(("Cryptodome", "SelfTest", "Signature", "test_vectors", "PKCS1-PSS"),
                                 "SigGenPSS_186-2.txt",
                                 "Signature Generation 186-2",
                                 { 'shaalg' : lambda x: x })

test_vectors_sign += load_tests(("Cryptodome", "SelfTest", "Signature", "test_vectors", "PKCS1-PSS"),
                                 "SigGenPSS_186-3.txt",
                                 "Signature Generation 186-3",
                                 { 'shaalg' : lambda x: x })

for count, tv in enumerate(test_vectors_sign):
    if isinstance(tv, str):
        continue
    if hasattr(tv, "n"):
        modulus = tv.n
        continue
    if hasattr(tv, "e"):
        private_key = RSA.construct([bytes_to_long(x) for x in (modulus, tv.e, tv.d)]) # type: ignore
        continue

    hash_module = load_hash_by_name(tv.shaalg.upper())
    hash_obj = hash_module.new(tv.msg)
    if tv.saltval != b("\x00"):
        prng = PRNG(tv.saltval)
        signer = pss.new(private_key, salt_bytes=len(tv.saltval), rand_func=prng)
    else:
        signer = pss.new(private_key, salt_bytes=0)

    def new_test(self, hash_obj=hash_obj, signer=signer, result=tv.s):
        signature = signer.sign(hash_obj)
        self.assertEqual(signature, result)

    setattr(FIPS_PKCS1_Sign_Tests_KAT, "test_%d" % count, new_test)


class PKCS1_Legacy_Module_Tests(unittest.TestCase):
    """Verify that the legacy module Cryptodome.Signature.PKCS1_PSS
    behaves as expected. The only difference is that the verify()
    method returns True/False and does not raise exceptions."""

    def shortDescription(self):
        return "Test legacy Cryptodome.Signature.PKCS1_PSS"

    def runTest(self):
        key = RSA.generate(1024)
        hashed = SHA1.new(b("Test"))
        good_signature = PKCS1_PSS.new(key).sign(hashed)
        verifier = PKCS1_PSS.new(key.publickey())

        self.assertEqual(verifier.verify(hashed, good_signature), True)

        # Flip a few bits in the signature
        bad_signature = strxor(good_signature, bchr(1) * len(good_signature))
        self.assertEqual(verifier.verify(hashed, bad_signature), False)


class PKCS1_All_Hashes_Tests(unittest.TestCase):

    def shortDescription(self):
        return "Test PKCS#1 PSS signature in combination with all hashes"

    def runTest(self):

        key = RSA.generate(1280)
        signer = pss.new(key)
        hash_names = ("MD2", "MD4", "MD5", "RIPEMD160", "SHA1",
                      "SHA224", "SHA256", "SHA384", "SHA512",
                      "SHA3_224", "SHA3_256", "SHA3_384", "SHA3_512")

        for name in hash_names:
            hashed = load_hash_by_name(name).new(b("Test"))
            signer.sign(hashed)

        from Cryptodome.Hash import BLAKE2b, BLAKE2s
        for hash_size in (20, 32, 48, 64):
            hashed_b = BLAKE2b.new(digest_bytes=hash_size, data=b("Test"))
            signer.sign(hashed_b)
        for hash_size in (16, 20, 28, 32):
            hashed_s = BLAKE2s.new(digest_bytes=hash_size, data=b("Test"))
            signer.sign(hashed_s)


def get_hash_module(hash_name):
    if hash_name == "SHA-512":
        hash_module = SHA512
    elif hash_name == "SHA-512/224":
        hash_module = SHA512.new(truncate="224")
    elif hash_name == "SHA-512/256":
        hash_module = SHA512.new(truncate="256")
    elif hash_name == "SHA-384":
        hash_module = SHA384
    elif hash_name == "SHA-256":
        hash_module = SHA256
    elif hash_name == "SHA-224":
        hash_module = SHA224
    elif hash_name == "SHA-1":
        hash_module = SHA1
    else:
        raise ValueError("Unknown hash algorithm: " + hash_name)
    return hash_module


class TestVectorsPSSWycheproof(unittest.TestCase):

    def __init__(self, wycheproof_warnings):
        unittest.TestCase.__init__(self)
        self._wycheproof_warnings = wycheproof_warnings
        self._id = "None"

    def add_tests(self, filename):
        comps = "Cryptodome.SelfTest.Signature.test_vectors.wycheproof".split(".")
        with open(pycryptodome_filename(comps, filename), "rt") as file_in:
            tv_tree = json.load(file_in)

        for group in tv_tree['testGroups']:

            key = RSA.import_key(group['keyPem'])
            hash_module = get_hash_module(group['sha'])
            sLen = group['sLen']

            assert group['type'] == "RsassaPssVerify"
            assert group['mgf'] == "MGF1"

            mgf1_hash =  get_hash_module(group['mgfSha'])

            def mgf(x, y, mh=mgf1_hash):
                return MGF1(x, y, mh)

            from collections import namedtuple
            TestVector = namedtuple('TestVector', 'id comment msg sig key mgf sLen hash_module valid warning')

            for test in group['tests']:
                tv = TestVector(
                    test['tcId'],
                    test['comment'],
                    unhexlify(test['msg']),
                    unhexlify(test['sig']),
                    key,
                    mgf,
                    sLen,
                    hash_module,
                    test['result'] != "invalid",
                    test['result'] == "acceptable"
                )
                self.tv.append(tv)

    def setUp(self):
        self.tv = []
        self.add_tests("rsa_pss_2048_sha1_mgf1_20_test.json")
        self.add_tests("rsa_pss_2048_sha256_mgf1_0_test.json")
        self.add_tests("rsa_pss_2048_sha256_mgf1_32_test.json")
        self.add_tests("rsa_pss_2048_sha512_256_mgf1_28_test.json")
        self.add_tests("rsa_pss_2048_sha512_256_mgf1_32_test.json")
        self.add_tests("rsa_pss_3072_sha256_mgf1_32_test.json")
        self.add_tests("rsa_pss_4096_sha256_mgf1_32_test.json")
        self.add_tests("rsa_pss_4096_sha512_mgf1_32_test.json")
        self.add_tests("rsa_pss_misc_test.json")

    def shortDescription(self):
        return self._id

    def warn(self, tv):
        if tv.warning and self._wycheproof_warnings:
            import warnings
            warnings.warn("Wycheproof warning: %s (%s)" % (self._id, tv.comment))

    def test_verify(self, tv):
        self._id = "Wycheproof RSA PSS Test #%d (%s)" % (tv.id, tv.comment)

        hashed_msg = tv.hash_module.new(tv.msg)
        signer = pss.new(tv.key, mask_func=tv.mgf, salt_bytes=tv.sLen)
        try:
            signature = signer.verify(hashed_msg, tv.sig)
        except ValueError as e:
            if tv.warning:
                return
            assert not tv.valid
        else:
            assert tv.valid
            self.warn(tv)

    def runTest(self):
        for tv in self.tv:
            self.test_verify(tv)


def get_tests(config={}):
    wycheproof_warnings = config.get('wycheproof_warnings')

    tests = []
    tests += list_test_cases(PSS_Tests)
    tests += list_test_cases(FIPS_PKCS1_Verify_Tests)
    tests += list_test_cases(FIPS_PKCS1_Sign_Tests)
    tests += list_test_cases(PKCS1_Legacy_Module_Tests)
    tests += list_test_cases(PKCS1_All_Hashes_Tests)

    if config.get('slow_tests'):
        tests += list_test_cases(FIPS_PKCS1_Verify_Tests_KAT)
        tests += list_test_cases(FIPS_PKCS1_Sign_Tests_KAT)

    tests += [ TestVectorsPSSWycheproof(wycheproof_warnings) ]

    return tests

if __name__ == '__main__':
    suite = lambda: unittest.TestSuite(get_tests())
    unittest.main(defaultTest='suite')
