113 lines
4.1 KiB
Plaintext
113 lines
4.1 KiB
Plaintext
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ABOUT
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--
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Bcrypt is a cross platform file encryption utility. Encrypted files are
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portable across all supported operating systems and processors. Passphrases
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are between 8 and 56 characters and are hashed internally to a 448 bit
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key. However, all characters supplied are significant. The stronger your
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passphrase, the more secure your data.
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Bcrypt uses the blowfish encryption algorithm published by Bruce Schneier
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in 1993. More information on the algorithm can be found at:
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http://www.counterpane.com/blowfish.html
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Specifically, bcrypt uses Paul Kocher's implementation of the algorithm.
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The source distributed with bcrypt has been slightly altered from the
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original. Original source code can be obtained from:
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http://www.counterpane.com/bfsh-koc.zip
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SUPPORTED PLATFORMS
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--
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Bcrypt has been successfully tested on the following platforms:
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x86
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FreeBSD, OpenBSD, Linux, Cygwin, Win32
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Sparc R220
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Solaris 2.7, 2.8
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Sparc Ultra60
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Linux 2.4
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Alpha
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Linux 2.4
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PPC G4
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MacOS X 10.1 SERVER
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PPC RS/6000
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Linux 2.4
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No other operating systems have been tested, but most should work with
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minimal modifications. If you get bcrypt to compile without errors on any
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other platform / architecture, I'd like to know about it. If patches are
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necessary to get bcrypt work on your OS, I will try to incorporate them
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into the main distribution.
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If you have a machine not listed above that is incapable of compiling
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bcrypt and are willing to give me access to the machine, I will make an
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attempt to port it to your OS.
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SYSTEM REQUIREMENTS
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--
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zlib - http://www.gzip.org/zlib/
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INSTALLATION
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--
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If you're so inclined, edit config.h and change the defaults to whatever
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you think is appropriate for your needs. If you choose not to have
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bcrypt remove input files after processing, or set SECUREDELETE to 0,
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you are likely to have data on your hard drive that can be recovered
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even after deletion.
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All of these options can be set on the command line as well. When you're
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satisfied with the default settings, simply type:
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make
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then su and type:
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make install
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It would be wise to test the installation on a few unimportant files
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before encrypting anything you value and removing the only copy.
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USAGE
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--
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bcrypt [-orc][-sN] file ...
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Encrypted files will be saved with an extension of .bfe. Any files ending
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in .bfe will be assumed to be encrypted with bcrypt and will attempt to
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decrypt them. Any other input files will be encrypted. If more than one
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type of file is given, bcrypt will process all files which are the same as
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the first filetype given.
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By default, bcrypt will compress input files before encryption, remove
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input files after they are processed (assuming they are processed
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successfully) and overwrite input files with random data to prevent data
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recovery.
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Passphrases may be between 8 and 56 characters. Regardless of the
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passphrase size, the key is hashed internally to 448 bits - the largest
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keysize supported by the blowfish algorithm. However, it is still wise to
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use a strong passphrase.
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OPTIONS
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-o print output to standard out. Implies -r.
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-c DO NOT compress files before encryption.
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-r DO NOT remove input files after processing
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-sN How many times to overwrite input files with random
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data before processing. The default number of
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overwrites is 3. Use -s0 to disable this feature.
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No effect if -r is supplied.
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The options o,c and r each have the opposite effects if the appropriate
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settings are altered from the default in config.h. To determine what
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effect each of these have, run bcrypt without any options.
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Encrypted files should be compatible between most systems. Binary
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compatibility has been tested for all systems listed above.
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/* ====================================================================
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* Copyright (c) 2002 Johnny Shelley. All rights reserved.
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*
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* Bcrypt is licensed under the BSD software license. See the file
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* called 'LICENSE' that you should have received with this software
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* for details
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* ====================================================================
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*/
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