FM / ciphers

/usr/lib64/python2.6/site-packages/cryptography/hazmat/primitives/ciphers/

/usr/lib64/python2.6/site-packages/cryptography/hazmat/primitives/ciphers

Name	Size	Mode	Actions
algorithms.py	3419	0644	edit dl rm
algorithms.pyc	7122	0644	edit dl rm
base.py	6169	0644	edit dl rm
base.pyc	9673	0644	edit dl rm
modes.py	4682	0644	edit dl rm
modes.pyc	7712	0644	edit dl rm
__init__.py	574	0644	edit dl rm
__init__.pyc	623	0644	edit dl rm

Edit: /usr/lib64/python2.6/site-packages/cryptography/hazmat/primitives/ciphers/base.py (6169B)

# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

from __future__ import absolute_import, division, print_function

import abc

import six

from cryptography import utils
from cryptography.exceptions import (
    AlreadyFinalized, AlreadyUpdated, NotYetFinalized, UnsupportedAlgorithm,
    _Reasons
)
from cryptography.hazmat.backends.interfaces import CipherBackend
from cryptography.hazmat.primitives.ciphers import modes

@six.add_metaclass(abc.ABCMeta)
class CipherAlgorithm(object):
    @abc.abstractproperty
    def name(self):
        """
        A string naming this mode (e.g. "AES", "Camellia").
        """

@abc.abstractproperty
    def key_size(self):
        """
        The size of the key being used as an integer in bits (e.g. 128, 256).
        """

@six.add_metaclass(abc.ABCMeta)
class BlockCipherAlgorithm(object):
    @abc.abstractproperty
    def block_size(self):
        """
        The size of a block as an integer in bits (e.g. 64, 128).
        """

@six.add_metaclass(abc.ABCMeta)
class CipherContext(object):
    @abc.abstractmethod
    def update(self, data):
        """
        Processes the provided bytes through the cipher and returns the results
        as bytes.
        """

@abc.abstractmethod
    def finalize(self):
        """
        Returns the results of processing the final block as bytes.
        """

@six.add_metaclass(abc.ABCMeta)
class AEADCipherContext(object):
    @abc.abstractmethod
    def authenticate_additional_data(self, data):
        """
        Authenticates the provided bytes.
        """

@six.add_metaclass(abc.ABCMeta)
class AEADEncryptionContext(object):
    @abc.abstractproperty
    def tag(self):
        """
        Returns tag bytes. This is only available after encryption is
        finalized.
        """

class Cipher(object):
    def __init__(self, algorithm, mode, backend):
        if not isinstance(backend, CipherBackend):
            raise UnsupportedAlgorithm(
                "Backend object does not implement CipherBackend.",
                _Reasons.BACKEND_MISSING_INTERFACE
            )

if not isinstance(algorithm, CipherAlgorithm):
            raise TypeError("Expected interface of CipherAlgorithm.")

if mode is not None:
            mode.validate_for_algorithm(algorithm)

self.algorithm = algorithm
        self.mode = mode
        self._backend = backend

def encryptor(self):
        if isinstance(self.mode, modes.ModeWithAuthenticationTag):
            if self.mode.tag is not None:
                raise ValueError(
                    "Authentication tag must be None when encrypting."
                )
        ctx = self._backend.create_symmetric_encryption_ctx(
            self.algorithm, self.mode
        )
        return self._wrap_ctx(ctx, encrypt=True)

def decryptor(self):
        if isinstance(self.mode, modes.ModeWithAuthenticationTag):
            if self.mode.tag is None:
                raise ValueError(
                    "Authentication tag must be provided when decrypting."
                )
        ctx = self._backend.create_symmetric_decryption_ctx(
            self.algorithm, self.mode
        )
        return self._wrap_ctx(ctx, encrypt=False)

def _wrap_ctx(self, ctx, encrypt):
        if isinstance(self.mode, modes.ModeWithAuthenticationTag):
            if encrypt:
                return _AEADEncryptionContext(ctx)
            else:
                return _AEADCipherContext(ctx)
        else:
            return _CipherContext(ctx)

@utils.register_interface(CipherContext)
class _CipherContext(object):
    def __init__(self, ctx):
        self._ctx = ctx

def update(self, data):
        if self._ctx is None:
            raise AlreadyFinalized("Context was already finalized.")
        return self._ctx.update(data)

def finalize(self):
        if self._ctx is None:
            raise AlreadyFinalized("Context was already finalized.")
        data = self._ctx.finalize()
        self._ctx = None
        return data

@utils.register_interface(AEADCipherContext)
@utils.register_interface(CipherContext)
class _AEADCipherContext(object):
    def __init__(self, ctx):
        self._ctx = ctx
        self._bytes_processed = 0
        self._aad_bytes_processed = 0
        self._tag = None
        self._updated = False

def update(self, data):
        if self._ctx is None:
            raise AlreadyFinalized("Context was already finalized.")
        self._updated = True
        self._bytes_processed += len(data)
        if self._bytes_processed > self._ctx._mode._MAX_ENCRYPTED_BYTES:
            raise ValueError(
                "{0} has a maximum encrypted byte limit of {1}".format(
                    self._ctx._mode.name, self._ctx._mode._MAX_ENCRYPTED_BYTES
                )
            )

return self._ctx.update(data)

def finalize(self):
        if self._ctx is None:
            raise AlreadyFinalized("Context was already finalized.")
        data = self._ctx.finalize()
        self._tag = self._ctx.tag
        self._ctx = None
        return data

def authenticate_additional_data(self, data):
        if self._ctx is None:
            raise AlreadyFinalized("Context was already finalized.")
        if self._updated:
            raise AlreadyUpdated("Update has been called on this context.")

self._aad_bytes_processed += len(data)
        if self._aad_bytes_processed > self._ctx._mode._MAX_AAD_BYTES:
            raise ValueError(
                "{0} has a maximum AAD byte limit of {0}".format(
                    self._ctx._mode.name, self._ctx._mode._MAX_AAD_BYTES
                )
            )

self._ctx.authenticate_additional_data(data)

@utils.register_interface(AEADEncryptionContext)
class _AEADEncryptionContext(_AEADCipherContext):
    @property
    def tag(self):
        if self._ctx is not None:
            raise NotYetFinalized("You must finalize encryption before "
                                  "getting the tag.")
        return self._tag

cmd: