NAME

des_modes - the variants of DES and other crypto algorithms of OpenSSL

DESCRIPTION

Several crypto algorithms for OpenSSL can be used in a number of modes. Those are used for using block ciphers in a way similar to stream ciphers, among other things.

OVERVIEW

Electronic Codebook Mode (ECB)

Normally, this is found as the function algorithm_ecb_encrypt().

Cipher Block Chaining Mode (CBC)

Normally, this is found as the function algorithm_cbc_encrypt(). Be aware that des_cbc_encrypt() is not really DES CBC (it does not update the IV); use des_ncbc_encrypt() instead.

Cipher Feedback Mode (CFB)

Normally, this is found as the function algorithm_cfb_encrypt().

Output Feedback Mode (OFB)

Normally, this is found as the function algorithm_ofb_encrypt().

Triple ECB Mode

Normally, this is found as the function algorithm_ecb3_encrypt().

Triple CBC Mode

Normally, this is found as the function algorithm_ede3_cbc_encrypt().

NOTES

This text was been written in large parts by Eric Young in his original documentation for SSLeay, the predecessor of OpenSSL. In turn, he attributed it to:

        AS 2805.5.2
        Australian Standard
        Electronic funds transfer - Requirements for interfaces,
        Part 5.2: Modes of operation for an n-bit block cipher algorithm
        Appendix A

SEE ALSO

BF_encrypt(3), DES_crypt(3)

COPYRIGHT

Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at https://www.openssl.org/source/license.html.