Python Crypto.Random.random.getrandbits() Examples

def encrypt_item(self, item, keys):
        uuid = item['uuid']
        content = json.dumps(item['content'])

        logging.debug('Encrypting item {} with content: {}'.format(uuid, content))

        # all this is to follow the Standard Notes spec
        item_key = hex(random.getrandbits(AES_KEY_LEN * 2))
        # remove '0x', pad with 0's, then split in half
        item_key = item_key[2:].rjust(AES_STR_KEY_LEN * 2, '0')
        item_ek = item_key[:AES_STR_KEY_LEN]
        item_ak = item_key[AES_STR_KEY_LEN:]

        enc_item = deepcopy(item)
        enc_item['content'] = self.encrypt_string_003(
                content, item_ek, item_ak, uuid)
        enc_item['enc_item_key'] = self.encrypt_string_003(
                item_key, keys['mk'], keys['ak'], uuid)

        return enc_item 

def encrypt_string_003(self, string_to_encrypt, encryption_key,
                                auth_key, uuid):
        IV = hex(random.getrandbits(AES_IV_LEN))
        IV = IV[2:].rjust(AES_STR_IV_LEN, '0') # remove '0x', pad with 0's

        cipher = AES.new(unhexlify(encryption_key), AES.MODE_CBC, unhexlify(IV))
        pt = string_to_encrypt.encode()
        padded_pt = Padding.pad(pt, AES.block_size)
        ciphertext = b64encode(cipher.encrypt(padded_pt)).decode()

        string_to_auth = ':'.join(['003', uuid, IV, ciphertext])
        auth_hash = hmac.new(
                unhexlify(auth_key), string_to_auth.encode(), 'sha256').digest()
        auth_hash = hexlify(auth_hash).decode()

        result = ':'.join(['003', auth_hash, uuid, IV, ciphertext])

        return result 

def init_p256():
    p = 0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff
    b = 0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b
    order = 0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551
    Gx = 0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296
    Gy = 0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5

    p256_modulus = long_to_bytes(p, 32)
    p256_b = long_to_bytes(b, 32)
    p256_order = long_to_bytes(order, 32)

    ec_p256_context = VoidPointer()
    result = _ec_lib.ec_ws_new_context(ec_p256_context.address_of(),
                                       c_uint8_ptr(p256_modulus),
                                       c_uint8_ptr(p256_b),
                                       c_uint8_ptr(p256_order),
                                       c_size_t(len(p256_modulus)),
                                       c_ulonglong(getrandbits(64))
                                       )
    if result:
        raise ImportError("Error %d initializing P-256 context" % result)

    context = SmartPointer(ec_p256_context.get(), _ec_lib.ec_free_context)
    p256 = _Curve(Integer(p),
                  Integer(b),
                  Integer(order),
                  Integer(Gx),
                  Integer(Gy),
                  None,
                  256,
                  "1.2.840.10045.3.1.7",    # ANSI X9.62
                  context,
                  "NIST P-256",
                  "ecdsa-sha2-nistp256")
    global p256_names
    _curves.update(dict.fromkeys(p256_names, p256)) 

def init_p384():
    p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffff0000000000000000ffffffff
    b = 0xb3312fa7e23ee7e4988e056be3f82d19181d9c6efe8141120314088f5013875ac656398d8a2ed19d2a85c8edd3ec2aef
    order = 0xffffffffffffffffffffffffffffffffffffffffffffffffc7634d81f4372ddf581a0db248b0a77aecec196accc52973
    Gx = 0xaa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760aB7
    Gy = 0x3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5F

    p384_modulus = long_to_bytes(p, 48)
    p384_b = long_to_bytes(b, 48)
    p384_order = long_to_bytes(order, 48)

    ec_p384_context = VoidPointer()
    result = _ec_lib.ec_ws_new_context(ec_p384_context.address_of(),
                                       c_uint8_ptr(p384_modulus),
                                       c_uint8_ptr(p384_b),
                                       c_uint8_ptr(p384_order),
                                       c_size_t(len(p384_modulus)),
                                       c_ulonglong(getrandbits(64))
                                       )
    if result:
        raise ImportError("Error %d initializing P-384 context" % result)

    context = SmartPointer(ec_p384_context.get(), _ec_lib.ec_free_context)
    p384 = _Curve(Integer(p),
                  Integer(b),
                  Integer(order),
                  Integer(Gx),
                  Integer(Gy),
                  None,
                  384,
                  "1.3.132.0.34",   # SEC 2
                  context,
                  "NIST P-384",
                  "ecdsa-sha2-nistp384")
    global p384_names
    _curves.update(dict.fromkeys(p384_names, p384)) 

def init_p521():
    p = 0x000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
    b = 0x00000051953eb9618e1c9a1f929a21a0b68540eea2da725b99b315f3b8b489918ef109e156193951ec7e937b1652c0bd3bb1bf073573df883d2c34f1ef451fd46b503f00
    order = 0x000001fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffa51868783bf2f966b7fcc0148f709a5d03bb5c9b8899c47aebb6fb71e91386409
    Gx = 0x000000c6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66
    Gy = 0x0000011839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650

    p521_modulus = long_to_bytes(p, 66)
    p521_b = long_to_bytes(b, 66)
    p521_order = long_to_bytes(order, 66)

    ec_p521_context = VoidPointer()
    result = _ec_lib.ec_ws_new_context(ec_p521_context.address_of(),
                                       c_uint8_ptr(p521_modulus),
                                       c_uint8_ptr(p521_b),
                                       c_uint8_ptr(p521_order),
                                       c_size_t(len(p521_modulus)),
                                       c_ulonglong(getrandbits(64))
                                       )
    if result:
        raise ImportError("Error %d initializing P-521 context" % result)

    context = SmartPointer(ec_p521_context.get(), _ec_lib.ec_free_context)
    p521 = _Curve(Integer(p),
                  Integer(b),
                  Integer(order),
                  Integer(Gx),
                  Integer(Gy),
                  None,
                  521,
                  "1.3.132.0.35",   # SEC 2
                  context,
                  "NIST P-521",
                  "ecdsa-sha2-nistp521")
    global p521_names
    _curves.update(dict.fromkeys(p521_names, p521)) 

def __imul__(self, scalar):
        """Multiply this point by a scalar"""

        if scalar < 0:
            raise ValueError("Scalar multiplication is only defined for non-negative integers")
        sb = long_to_bytes(scalar)
        result = _ec_lib.ec_ws_scalar(self._point.get(),
                                      c_uint8_ptr(sb),
                                      c_size_t(len(sb)),
                                      c_ulonglong(getrandbits(64)))
        if result:
            raise ValueError("Error %d during scalar multiplication" % result)
        return self 

def init_p256():
    p = 0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff
    b = 0x5ac635d8aa3a93e7b3ebbd55769886bc651d06b0cc53b0f63bce3c3e27d2604b
    order = 0xffffffff00000000ffffffffffffffffbce6faada7179e84f3b9cac2fc632551
    Gx = 0x6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296
    Gy = 0x4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5

    p256_modulus = long_to_bytes(p, 32)
    p256_b = long_to_bytes(b, 32)
    p256_order = long_to_bytes(order, 32)

    ec_p256_context = VoidPointer()
    result = _ec_lib.ec_ws_new_context(ec_p256_context.address_of(),
                                       c_uint8_ptr(p256_modulus),
                                       c_uint8_ptr(p256_b),
                                       c_uint8_ptr(p256_order),
                                       c_size_t(len(p256_modulus)),
                                       c_ulonglong(getrandbits(64))
                                       )
    if result:
        raise ImportError("Error %d initializing P-256 context" % result)

    context = SmartPointer(ec_p256_context.get(), _ec_lib.ec_free_context)
    p256 = _Curve(Integer(p),
                  Integer(b),
                  Integer(order),
                  Integer(Gx),
                  Integer(Gy),
                  None,
                  256,
                  "1.2.840.10045.3.1.7",    # ANSI X9.62
                  context,
                  "NIST P-256",
                  "ecdsa-sha2-nistp256")
    global p256_names
    _curves.update(dict.fromkeys(p256_names, p256)) 

def init_p384():
    p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffeffffffff0000000000000000ffffffff
    b = 0xb3312fa7e23ee7e4988e056be3f82d19181d9c6efe8141120314088f5013875ac656398d8a2ed19d2a85c8edd3ec2aef
    order = 0xffffffffffffffffffffffffffffffffffffffffffffffffc7634d81f4372ddf581a0db248b0a77aecec196accc52973
    Gx = 0xaa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760aB7
    Gy = 0x3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5F

    p384_modulus = long_to_bytes(p, 48)
    p384_b = long_to_bytes(b, 48)
    p384_order = long_to_bytes(order, 48)

    ec_p384_context = VoidPointer()
    result = _ec_lib.ec_ws_new_context(ec_p384_context.address_of(),
                                       c_uint8_ptr(p384_modulus),
                                       c_uint8_ptr(p384_b),
                                       c_uint8_ptr(p384_order),
                                       c_size_t(len(p384_modulus)),
                                       c_ulonglong(getrandbits(64))
                                       )
    if result:
        raise ImportError("Error %d initializing P-384 context" % result)

    context = SmartPointer(ec_p384_context.get(), _ec_lib.ec_free_context)
    p384 = _Curve(Integer(p),
                  Integer(b),
                  Integer(order),
                  Integer(Gx),
                  Integer(Gy),
                  None,
                  384,
                  "1.3.132.0.34",   # SEC 2
                  context,
                  "NIST P-384",
                  "ecdsa-sha2-nistp384")
    global p384_names
    _curves.update(dict.fromkeys(p384_names, p384)) 

def init_p521():
    p = 0x000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff
    b = 0x00000051953eb9618e1c9a1f929a21a0b68540eea2da725b99b315f3b8b489918ef109e156193951ec7e937b1652c0bd3bb1bf073573df883d2c34f1ef451fd46b503f00
    order = 0x000001fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffa51868783bf2f966b7fcc0148f709a5d03bb5c9b8899c47aebb6fb71e91386409
    Gx = 0x000000c6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66
    Gy = 0x0000011839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650

    p521_modulus = long_to_bytes(p, 66)
    p521_b = long_to_bytes(b, 66)
    p521_order = long_to_bytes(order, 66)

    ec_p521_context = VoidPointer()
    result = _ec_lib.ec_ws_new_context(ec_p521_context.address_of(),
                                       c_uint8_ptr(p521_modulus),
                                       c_uint8_ptr(p521_b),
                                       c_uint8_ptr(p521_order),
                                       c_size_t(len(p521_modulus)),
                                       c_ulonglong(getrandbits(64))
                                       )
    if result:
        raise ImportError("Error %d initializing P-521 context" % result)

    context = SmartPointer(ec_p521_context.get(), _ec_lib.ec_free_context)
    p521 = _Curve(Integer(p),
                  Integer(b),
                  Integer(order),
                  Integer(Gx),
                  Integer(Gy),
                  None,
                  521,
                  "1.3.132.0.35",   # SEC 2
                  context,
                  "NIST P-521",
                  "ecdsa-sha2-nistp521")
    global p521_names
    _curves.update(dict.fromkeys(p521_names, p521)) 

def __imul__(self, scalar):
        """Multiply this point by a scalar"""

        if scalar < 0:
            raise ValueError("Scalar multiplication is only defined for non-negative integers")
        sb = long_to_bytes(scalar)
        result = _ec_lib.ec_ws_scalar(self._point.get(),
                                      c_uint8_ptr(sb),
                                      c_size_t(len(sb)),
                                      c_ulonglong(getrandbits(64)))
        if result:
            raise ValueError("Error %d during scalar multiplication" % result)
        return self 

def inplace_pow(self, exponent, modulus=None):
        exp_value = int(exponent)
        if exp_value < 0:
            raise ValueError("Exponent must not be negative")

        # No modular reduction
        if modulus is None:
            self._value = pow(self._value, exp_value)
            return self

        # With modular reduction
        mod_value = int(modulus)
        if mod_value < 0:
            raise ValueError("Modulus must be positive")
        if mod_value == 0:
            raise ZeroDivisionError("Modulus cannot be zero")

        # C extension only works with odd moduli
        if (mod_value & 1) == 0:
            self._value = pow(self._value, exp_value, mod_value)
            return self

        # C extension only works with bases smaller than modulus
        if self._value >= mod_value:
            self._value %= mod_value

        max_len = len(long_to_bytes(max(self._value, exp_value, mod_value)))

        base_b = long_to_bytes(self._value, max_len)
        exp_b = long_to_bytes(exp_value, max_len)
        modulus_b = long_to_bytes(mod_value, max_len)

        out = create_string_buffer(max_len)

        error = _raw_montgomery.monty_pow(
                    out,
                    base_b,
                    exp_b,
                    modulus_b,
                    c_size_t(max_len),
                    c_ulonglong(getrandbits(64))
                    )

        if error:
            raise ValueError("monty_pow failed with error: %d" % error)

        result = bytes_to_long(get_raw_buffer(out))
        self._value = result
        return self 

def inplace_pow(self, exponent, modulus=None):
        exp_value = int(exponent)
        if exp_value < 0:
            raise ValueError("Exponent must not be negative")

        # No modular reduction
        if modulus is None:
            self._value = pow(self._value, exp_value)
            return self

        # With modular reduction
        mod_value = int(modulus)
        if mod_value < 0:
            raise ValueError("Modulus must be positive")
        if mod_value == 0:
            raise ZeroDivisionError("Modulus cannot be zero")

        # C extension only works with odd moduli
        if (mod_value & 1) == 0:
            self._value = pow(self._value, exp_value, mod_value)
            return self

        # C extension only works with bases smaller than modulus
        if self._value >= mod_value:
            self._value %= mod_value

        max_len = len(long_to_bytes(max(self._value, exp_value, mod_value)))

        base_b = long_to_bytes(self._value, max_len)
        exp_b = long_to_bytes(exp_value, max_len)
        modulus_b = long_to_bytes(mod_value, max_len)

        out = create_string_buffer(max_len)

        error = _raw_montgomery.monty_pow(
                    out,
                    base_b,
                    exp_b,
                    modulus_b,
                    c_size_t(max_len),
                    c_ulonglong(getrandbits(64))
                    )

        if error:
            raise ValueError("monty_pow failed with error: %d" % error)

        result = bytes_to_long(get_raw_buffer(out))
        self._value = result
        return self