FM / Cipher

/opt/alt/python27/lib64/python2.7/site-packages/Crypto/Cipher/

/opt/alt/python27/lib64/python2.7/site-packages/Crypto/Cipher

Name	Size	Mode	Actions
AES.py	4218	0644	edit dl rm
AES.pyc	3567	0644	edit dl rm
AES.pyo	3567	0644	edit dl rm
ARC2.py	4917	0644	edit dl rm
ARC2.pyc	4265	0644	edit dl rm
ARC2.pyo	4265	0644	edit dl rm
ARC4.py	4266	0644	edit dl rm
ARC4.pyc	4059	0644	edit dl rm
ARC4.pyo	4059	0644	edit dl rm
blockalgo.py	12596	0644	edit dl rm
blockalgo.pyc	6307	0644	edit dl rm
blockalgo.pyo	6307	0644	edit dl rm
Blowfish.py	4460	0644	edit dl rm
Blowfish.pyc	3810	0644	edit dl rm
Blowfish.pyo	3810	0644	edit dl rm
CAST.py	4498	0644	edit dl rm
CAST.pyc	3847	0644	edit dl rm
CAST.pyo	3847	0644	edit dl rm
DES.py	4403	0644	edit dl rm
DES.pyc	3738	0644	edit dl rm
DES.pyo	3738	0644	edit dl rm
DES3.py	5130	0644	edit dl rm
DES3.pyc	4481	0644	edit dl rm
DES3.pyo	4481	0644	edit dl rm
PKCS1_OAEP.py	9373	0644	edit dl rm
PKCS1_OAEP.pyc	8649	0644	edit dl rm
PKCS1_OAEP.pyo	8649	0644	edit dl rm
PKCS1_v1_5.py	9103	0644	edit dl rm
PKCS1_v1_5.pyc	9280	0644	edit dl rm
PKCS1_v1_5.pyo	9280	0644	edit dl rm
XOR.py	2737	0644	edit dl rm
XOR.pyc	2531	0644	edit dl rm
XOR.pyo	2531	0644	edit dl rm
_AES.so	63128	0755	edit dl rm
_ARC2.so	44977	0755	edit dl rm
_ARC4.so	28080	0755	edit dl rm
_Blowfish.so	55963	0755	edit dl rm
_CAST.so	57103	0755	edit dl rm
_DES.so	88934	0755	edit dl rm
_DES3.so	89056	0755	edit dl rm
_XOR.so	28428	0755	edit dl rm
__init__.py	3440	0644	edit dl rm
__init__.pyc	2647	0644	edit dl rm
__init__.pyo	2647	0644	edit dl rm

Edit: /opt/alt/python27/lib64/python2.7/site-packages/Crypto/Cipher/blockalgo.py (12596B)

# -*- coding: utf-8 -*-
#
#  Cipher/blockalgo.py 
#
# ===================================================================
# The contents of this file are dedicated to the public domain.  To
# the extent that dedication to the public domain is not available,
# everyone is granted a worldwide, perpetual, royalty-free,
# non-exclusive license to exercise all rights associated with the
# contents of this file for any purpose whatsoever.
# No rights are reserved.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
# ===================================================================
"""Module with definitions common to all block ciphers."""

import sys
if sys.version_info[0] == 2 and sys.version_info[1] == 1:
    from Crypto.Util.py21compat import *
from Crypto.Util.py3compat import *

#: *Electronic Code Book (ECB)*.
#: This is the simplest encryption mode. Each of the plaintext blocks
#: is directly encrypted into a ciphertext block, independently of
#: any other block. This mode exposes frequency of symbols
#: in your plaintext. Other modes (e.g. *CBC*) should be used instead.
#:
#: See `NIST SP800-38A`_ , Section 6.1 .
#:
#: .. _`NIST SP800-38A` : http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
MODE_ECB = 1

#: *Cipher-Block Chaining (CBC)*. Each of the ciphertext blocks depends
#: on the current and all previous plaintext blocks. An Initialization Vector
#: (*IV*) is required.
#:
#: The *IV* is a data block to be transmitted to the receiver.
#: The *IV* can be made public, but it must be authenticated by the receiver and
#: it should be picked randomly.
#:
#: See `NIST SP800-38A`_ , Section 6.2 .
#:
#: .. _`NIST SP800-38A` : http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
MODE_CBC = 2

#: *Cipher FeedBack (CFB)*. This mode is similar to CBC, but it transforms
#: the underlying block cipher into a stream cipher. Plaintext and ciphertext
#: are processed in *segments* of **s** bits. The mode is therefore sometimes
#: labelled **s**-bit CFB. An Initialization Vector (*IV*) is required.
#:
#: When encrypting, each ciphertext segment contributes to the encryption of
#: the next plaintext segment.
#:
#: This *IV* is a data block to be transmitted to the receiver.
#: The *IV* can be made public, but it should be picked randomly.
#: Reusing the same *IV* for encryptions done with the same key lead to
#: catastrophic cryptographic failures.
#:
#: See `NIST SP800-38A`_ , Section 6.3 .
#:
#: .. _`NIST SP800-38A` : http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
MODE_CFB = 3

#: This mode should not be used.
MODE_PGP = 4

#: *Output FeedBack (OFB)*. This mode is very similar to CBC, but it
#: transforms the underlying block cipher into a stream cipher.
#: The keystream is the iterated block encryption of an Initialization Vector (*IV*).
#:
#: The *IV* is a data block to be transmitted to the receiver.
#: The *IV* can be made public, but it should be picked randomly.
#:
#: Reusing the same *IV* for encryptions done with the same key lead to
#: catastrophic cryptograhic failures.
#:
#: See `NIST SP800-38A`_ , Section 6.4 .
#:
#: .. _`NIST SP800-38A` : http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
MODE_OFB = 5

#: *CounTeR (CTR)*. This mode is very similar to ECB, in that
#: encryption of one block is done independently of all other blocks.
#: Unlike ECB, the block *position* contributes to the encryption and no
#: information leaks about symbol frequency.
#:
#: Each message block is associated to a *counter* which must be unique
#: across all messages that get encrypted with the same key (not just within
#: the same message). The counter is as big as the block size.
#:
#: Counters can be generated in several ways. The most straightword one is
#: to choose an *initial counter block* (which can be made public, similarly
#: to the *IV* for the other modes) and increment its lowest **m** bits by
#: one (modulo *2^m*) for each block. In most cases, **m** is chosen to be half
#: the block size.
#: 
#: Reusing the same *initial counter block* for encryptions done with the same
#: key lead to catastrophic cryptograhic failures.
#:
#: See `NIST SP800-38A`_ , Section 6.5 (for the mode) and Appendix B (for how
#: to manage the *initial counter block*).
#:
#: .. _`NIST SP800-38A` : http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf
MODE_CTR = 6

#: OpenPGP. This mode is a variant of CFB, and it is only used in PGP and OpenPGP_ applications.
#: An Initialization Vector (*IV*) is required.
#: 
#: Unlike CFB, the IV is not transmitted to the receiver. Instead, the *encrypted* IV is.
#: The IV is a random data block. Two of its bytes are duplicated to act as a checksum
#: for the correctness of the key. The encrypted IV is therefore 2 bytes longer than
#: the clean IV.
#:
#: .. _OpenPGP: http://tools.ietf.org/html/rfc4880
MODE_OPENPGP = 7

def _getParameter(name, index, args, kwargs, default=None):
    """Find a parameter in tuple and dictionary arguments a function receives"""
    param = kwargs.get(name)
    if len(args)>index:
        if param:
            raise ValueError("Parameter '%s' is specified twice" % name)
        param = args[index]
    return param or default
    
class BlockAlgo:
    """Class modelling an abstract block cipher."""

def __init__(self, factory, key, *args, **kwargs):
        self.mode = _getParameter('mode', 0, args, kwargs, default=MODE_ECB)
        self.block_size = factory.block_size
        
        if self.mode != MODE_OPENPGP:
            self._cipher = factory.new(key, *args, **kwargs)
            self.IV = self._cipher.IV
        else:
            # OPENPGP mode. For details, see 13.9 in RCC4880.
            #
            # A few members are specifically created for this mode:
            #  - _encrypted_iv, set in this constructor
            #  - _done_first_block, set to True after the first encryption
            #  - _done_last_block, set to True after a partial block is processed
            
            self._done_first_block = False
            self._done_last_block = False
            self.IV = _getParameter('iv', 1, args, kwargs)
            if not self.IV:
                raise ValueError("MODE_OPENPGP requires an IV")
            
            # Instantiate a temporary cipher to process the IV
            IV_cipher = factory.new(key, MODE_CFB,
                    b('\x00')*self.block_size,      # IV for CFB
                    segment_size=self.block_size*8)
           
            # The cipher will be used for...
            if len(self.IV) == self.block_size:
                # ... encryption
                self._encrypted_IV = IV_cipher.encrypt(
                    self.IV + self.IV[-2:] +        # Plaintext
                    b('\x00')*(self.block_size-2)   # Padding
                    )[:self.block_size+2]
            elif len(self.IV) == self.block_size+2:
                # ... decryption
                self._encrypted_IV = self.IV
                self.IV = IV_cipher.decrypt(self.IV +   # Ciphertext
                    b('\x00')*(self.block_size-2)       # Padding
                    )[:self.block_size+2]
                if self.IV[-2:] != self.IV[-4:-2]:
                    raise ValueError("Failed integrity check for OPENPGP IV")
                self.IV = self.IV[:-2]
            else:
                raise ValueError("Length of IV must be %d or %d bytes for MODE_OPENPGP"
                    % (self.block_size, self.block_size+2))

# Instantiate the cipher for the real PGP data
            self._cipher = factory.new(key, MODE_CFB,
                self._encrypted_IV[-self.block_size:],
                segment_size=self.block_size*8)

def encrypt(self, plaintext):
        """Encrypt data with the key and the parameters set at initialization.
        
        The cipher object is stateful; encryption of a long block
        of data can be broken up in two or more calls to `encrypt()`.
        That is, the statement:
            
            >>> c.encrypt(a) + c.encrypt(b)

is always equivalent to:

>>> c.encrypt(a+b)

That also means that you cannot reuse an object for encrypting
        or decrypting other data with the same key.

This function does not perform any padding.
       
         - For `MODE_ECB`, `MODE_CBC`, and `MODE_OFB`, *plaintext* length
           (in bytes) must be a multiple of *block_size*.

- For `MODE_CFB`, *plaintext* length (in bytes) must be a multiple
           of *segment_size*/8.

- For `MODE_CTR`, *plaintext* can be of any length.

- For `MODE_OPENPGP`, *plaintext* must be a multiple of *block_size*,
           unless it is the last chunk of the message.

:Parameters:
          plaintext : byte string
            The piece of data to encrypt.
        :Return:
            the encrypted data, as a byte string. It is as long as
            *plaintext* with one exception: when encrypting the first message
            chunk with `MODE_OPENPGP`, the encypted IV is prepended to the
            returned ciphertext.
        """

if self.mode == MODE_OPENPGP:
            padding_length = (self.block_size - len(plaintext) % self.block_size) % self.block_size
            if padding_length>0:
                # CFB mode requires ciphertext to have length multiple of block size,
                # but PGP mode allows the last block to be shorter
                if self._done_last_block:
                    raise ValueError("Only the last chunk is allowed to have length not multiple of %d bytes",
                        self.block_size)
                self._done_last_block = True
                padded = plaintext + b('\x00')*padding_length
                res = self._cipher.encrypt(padded)[:len(plaintext)]
            else:
                res = self._cipher.encrypt(plaintext)
            if not self._done_first_block:
                res = self._encrypted_IV + res
                self._done_first_block = True
            return res

return self._cipher.encrypt(plaintext)

def decrypt(self, ciphertext):
        """Decrypt data with the key and the parameters set at initialization.
        
        The cipher object is stateful; decryption of a long block
        of data can be broken up in two or more calls to `decrypt()`.
        That is, the statement:
            
            >>> c.decrypt(a) + c.decrypt(b)

is always equivalent to:

>>> c.decrypt(a+b)

That also means that you cannot reuse an object for encrypting
        or decrypting other data with the same key.

This function does not perform any padding.
       
         - For `MODE_ECB`, `MODE_CBC`, and `MODE_OFB`, *ciphertext* length
           (in bytes) must be a multiple of *block_size*.

- For `MODE_CFB`, *ciphertext* length (in bytes) must be a multiple
           of *segment_size*/8.

- For `MODE_CTR`, *ciphertext* can be of any length.

- For `MODE_OPENPGP`, *plaintext* must be a multiple of *block_size*,
           unless it is the last chunk of the message.

:Parameters:
          ciphertext : byte string
            The piece of data to decrypt.
        :Return: the decrypted data (byte string, as long as *ciphertext*).
        """
        if self.mode == MODE_OPENPGP:
            padding_length = (self.block_size - len(ciphertext) % self.block_size) % self.block_size
            if padding_length>0:
                # CFB mode requires ciphertext to have length multiple of block size,
                # but PGP mode allows the last block to be shorter
                if self._done_last_block:
                    raise ValueError("Only the last chunk is allowed to have length not multiple of %d bytes",
                        self.block_size)
                self._done_last_block = True
                padded = ciphertext + b('\x00')*padding_length
                res = self._cipher.decrypt(padded)[:len(ciphertext)]
            else:
                res = self._cipher.decrypt(ciphertext)
            return res

return self._cipher.decrypt(ciphertext)

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