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Diffstat (limited to 'rsa/bigfile.py')
| -rw-r--r-- | rsa/bigfile.py | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/rsa/bigfile.py b/rsa/bigfile.py deleted file mode 100644 index 3a09716..0000000 --- a/rsa/bigfile.py +++ /dev/null @@ -1,135 +0,0 @@ -# -*- coding: utf-8 -*- -# -# Copyright 2011 Sybren A. Stüvel <sybren@stuvel.eu> -# -# Licensed under the Apache License, Version 2.0 (the "License"); -# you may not use this file except in compliance with the License. -# You may obtain a copy of the License at -# -# https://www.apache.org/licenses/LICENSE-2.0 -# -# Unless required by applicable law or agreed to in writing, software -# distributed under the License is distributed on an "AS IS" BASIS, -# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. -# See the License for the specific language governing permissions and -# limitations under the License. - -"""Large file support - -.. deprecated:: 3.4 - - The VARBLOCK format is NOT recommended for general use, has been deprecated since - Python-RSA 3.4, and will be removed in a future release. It's vulnerable to a - number of attacks: - - 1. decrypt/encrypt_bigfile() does not implement `Authenticated encryption`_ nor - uses MACs to verify messages before decrypting public key encrypted messages. - - 2. decrypt/encrypt_bigfile() does not use hybrid encryption (it uses plain RSA) - and has no method for chaining, so block reordering is possible. - - See `issue #19 on Github`_ for more information. - -.. _Authenticated encryption: https://en.wikipedia.org/wiki/Authenticated_encryption -.. _issue #19 on Github: https://github.com/sybrenstuvel/python-rsa/issues/13 - - -This module contains functions to: - - - break a file into smaller blocks, and encrypt them, and store the - encrypted blocks in another file. - - - take such an encrypted files, decrypt its blocks, and reconstruct the - original file. - -The encrypted file format is as follows, where || denotes byte concatenation: - - FILE := VERSION || BLOCK || BLOCK ... - - BLOCK := LENGTH || DATA - - LENGTH := varint-encoded length of the subsequent data. Varint comes from - Google Protobuf, and encodes an integer into a variable number of bytes. - Each byte uses the 7 lowest bits to encode the value. The highest bit set - to 1 indicates the next byte is also part of the varint. The last byte will - have this bit set to 0. - -This file format is called the VARBLOCK format, in line with the varint format -used to denote the block sizes. - -""" - -import warnings - -from rsa import key, common, pkcs1, varblock -from rsa._compat import byte - - -def encrypt_bigfile(infile, outfile, pub_key): - """Encrypts a file, writing it to 'outfile' in VARBLOCK format. - - .. deprecated:: 3.4 - This function was deprecated in Python-RSA version 3.4 due to security issues - in the VARBLOCK format. See the documentation_ for more information. - - .. _documentation: https://stuvel.eu/python-rsa-doc/usage.html#working-with-big-files - - :param infile: file-like object to read the cleartext from - :param outfile: file-like object to write the crypto in VARBLOCK format to - :param pub_key: :py:class:`rsa.PublicKey` to encrypt with - - """ - - warnings.warn("The 'rsa.bigfile.encrypt_bigfile' function was deprecated in Python-RSA version " - "3.4 due to security issues in the VARBLOCK format. See " - "https://stuvel.eu/python-rsa-doc/usage.html#working-with-big-files " - "for more information.", - DeprecationWarning, stacklevel=2) - - if not isinstance(pub_key, key.PublicKey): - raise TypeError('Public key required, but got %r' % pub_key) - - key_bytes = common.bit_size(pub_key.n) // 8 - blocksize = key_bytes - 11 # keep space for PKCS#1 padding - - # Write the version number to the VARBLOCK file - outfile.write(byte(varblock.VARBLOCK_VERSION)) - - # Encrypt and write each block - for block in varblock.yield_fixedblocks(infile, blocksize): - crypto = pkcs1.encrypt(block, pub_key) - - varblock.write_varint(outfile, len(crypto)) - outfile.write(crypto) - - -def decrypt_bigfile(infile, outfile, priv_key): - """Decrypts an encrypted VARBLOCK file, writing it to 'outfile' - - .. deprecated:: 3.4 - This function was deprecated in Python-RSA version 3.4 due to security issues - in the VARBLOCK format. See the documentation_ for more information. - - .. _documentation: https://stuvel.eu/python-rsa-doc/usage.html#working-with-big-files - - :param infile: file-like object to read the crypto in VARBLOCK format from - :param outfile: file-like object to write the cleartext to - :param priv_key: :py:class:`rsa.PrivateKey` to decrypt with - - """ - - warnings.warn("The 'rsa.bigfile.decrypt_bigfile' function was deprecated in Python-RSA version " - "3.4 due to security issues in the VARBLOCK format. See " - "https://stuvel.eu/python-rsa-doc/usage.html#working-with-big-files " - "for more information.", - DeprecationWarning, stacklevel=2) - - if not isinstance(priv_key, key.PrivateKey): - raise TypeError('Private key required, but got %r' % priv_key) - - for block in varblock.yield_varblocks(infile): - cleartext = pkcs1.decrypt(block, priv_key) - outfile.write(cleartext) - - -__all__ = ['encrypt_bigfile', 'decrypt_bigfile'] |