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Diffstat (limited to 'frozen_deps/Crypto/Cipher/DES3.py')
| -rw-r--r-- | frozen_deps/Crypto/Cipher/DES3.py | 133 |
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diff --git a/frozen_deps/Crypto/Cipher/DES3.py b/frozen_deps/Crypto/Cipher/DES3.py deleted file mode 100644 index 7fedac8..0000000 --- a/frozen_deps/Crypto/Cipher/DES3.py +++ /dev/null @@ -1,133 +0,0 @@ -# -*- coding: utf-8 -*- -# -# Cipher/DES3.py : DES3 -# -# =================================================================== -# 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. -# =================================================================== -"""Triple DES symmetric cipher - -`Triple DES`__ (or TDES or TDEA or 3DES) is a symmetric block cipher standardized by NIST_. -It has a fixed data block size of 8 bytes. Its keys are 128 (*Option 1*) or 192 -bits (*Option 2*) long. -However, 1 out of 8 bits is used for redundancy and do not contribute to -security. The effective key length is respectively 112 or 168 bits. - -TDES consists of the concatenation of 3 simple `DES` ciphers. - -The plaintext is first DES encrypted with *K1*, then decrypted with *K2*, -and finally encrypted again with *K3*. The ciphertext is decrypted in the reverse manner. - -The 192 bit key is a bundle of three 64 bit independent subkeys: *K1*, *K2*, and *K3*. - -The 128 bit key is split into *K1* and *K2*, whereas *K1=K3*. - -It is important that all subkeys are different, otherwise TDES would degrade to -single `DES`. - -TDES is cryptographically secure, even though it is neither as secure nor as fast -as `AES`. - -As an example, encryption can be done as follows: - - >>> from Crypto.Cipher import DES - >>> from Crypto import Random - >>> from Crypto.Util import Counter - >>> - >>> key = b'-8B key-' - >>> nonce = Random.new().read(DES.block_size/2) - >>> ctr = Counter.new(DES.block_size*8/2, prefix=nonce) - >>> cipher = DES.new(key, DES.MODE_CTR, counter=ctr) - >>> plaintext = b'We are no longer the knights who say ni!' - >>> msg = nonce + cipher.encrypt(plaintext) - -.. __: http://en.wikipedia.org/wiki/Triple_DES -.. _NIST: http://csrc.nist.gov/publications/nistpubs/800-67/SP800-67.pdf - -:undocumented: __revision__, __package__ -""" - -__revision__ = "$Id$" - -from Crypto.Cipher import blockalgo -from Crypto.Cipher import _DES3 - -class DES3Cipher(blockalgo.BlockAlgo): - """TDES cipher object""" - - def __init__(self, key, *args, **kwargs): - """Initialize a TDES cipher object - - See also `new()` at the module level.""" - blockalgo.BlockAlgo.__init__(self, _DES3, key, *args, **kwargs) - -def new(key, *args, **kwargs): - """Create a new TDES cipher - - :Parameters: - key : byte string - The secret key to use in the symmetric cipher. - It must be 16 or 24 bytes long. The parity bits will be ignored. - :Keywords: - mode : a *MODE_** constant - The chaining mode to use for encryption or decryption. - Default is `MODE_ECB`. - IV : byte string - The initialization vector to use for encryption or decryption. - - It is ignored for `MODE_ECB` and `MODE_CTR`. - - For `MODE_OPENPGP`, IV must be `block_size` bytes long for encryption - and `block_size` +2 bytes for decryption (in the latter case, it is - actually the *encrypted* IV which was prefixed to the ciphertext). - It is mandatory. - - For all other modes, it must be `block_size` bytes longs. It is optional and - when not present it will be given a default value of all zeroes. - counter : callable - (*Only* `MODE_CTR`). A stateful function that returns the next - *counter block*, which is a byte string of `block_size` bytes. - For better performance, use `Crypto.Util.Counter`. - segment_size : integer - (*Only* `MODE_CFB`).The number of bits the plaintext and ciphertext - are segmented in. - It must be a multiple of 8. If 0 or not specified, it will be assumed to be 8. - - :Attention: it is important that all 8 byte subkeys are different, - otherwise TDES would degrade to single `DES`. - :Return: an `DES3Cipher` object - """ - return DES3Cipher(key, *args, **kwargs) - -#: Electronic Code Book (ECB). See `blockalgo.MODE_ECB`. -MODE_ECB = 1 -#: Cipher-Block Chaining (CBC). See `blockalgo.MODE_CBC`. -MODE_CBC = 2 -#: Cipher FeedBack (CFB). See `blockalgo.MODE_CFB`. -MODE_CFB = 3 -#: This mode should not be used. -MODE_PGP = 4 -#: Output FeedBack (OFB). See `blockalgo.MODE_OFB`. -MODE_OFB = 5 -#: CounTer Mode (CTR). See `blockalgo.MODE_CTR`. -MODE_CTR = 6 -#: OpenPGP Mode. See `blockalgo.MODE_OPENPGP`. -MODE_OPENPGP = 7 -#: Size of a data block (in bytes) -block_size = 8 -#: Size of a key (in bytes) -key_size = ( 16, 24 ) |