1.\" $OpenBSD: blowfish.3,v 1.13 2005/07/17 08:50:55 jaredy Exp $ 2.\" 3.\" Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de> 4.\" All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by Niels Provos. 17.\" 4. The name of the author may not be used to endorse or promote products 18.\" derived from this software without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 21.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30.\" 31.\" Manual page, using -mandoc macros 32.\" 33.Dd February 13, 1997 34.Dt BLOWFISH 3 35.Os 36.Sh NAME 37.Nm blf_key , 38.Nm blf_enc , 39.Nm blf_dec 40.Nd Blowfish encryption 41.Sh SYNOPSIS 42.Fd #include <blf.h> 43.Ft void 44.Fn blf_key "blf_ctx *state" "const u_int8_t *key" "u_int16_t keylen" 45.Ft void 46.Fn blf_enc "blf_ctx *state" "u_int32_t *data" "u_int16_t datalen" 47.Ft void 48.Fn blf_dec "blf_ctx *state" "u_int32_t *data" "u_int16_t datalen" 49.Ft void 50.Fn blf_ecb_encrypt "blf_ctx *state" "u_int8_t *data" "u_int32_t datalen" 51.Ft void 52.Fn blf_ecb_decrypt "blf_ctx *state" "u_int8_t *data" "u_int32_t datalen" 53.Ft void 54.Fn blf_cbc_encrypt "blf_ctx *state" "u_int8_t *iv" "u_int8_t *data" "u_int32_t datalen" 55.Ft void 56.Fn blf_cbc_decrypt "blf_ctx *state" "u_int8_t *iv" "u_int8_t *data" "u_int32_t datalen" 57.Sh DESCRIPTION 58.Pa Blowfish 59is a fast unpatented block cipher designed by Bruce Schneier. 60It basically consists of a 16-round Feistel network. 61The block size is 64 bits and the maximum key size is 448 bits. 62.Pp 63The 64.Fn blf_key 65function initializes the 4 8-bit S-boxes and the 18 Subkeys with 66the hexadecimal digits of Pi. 67The key is used for further randomization. 68The first argument to 69.Fn blf_enc 70is the initialized state derived from 71.Fn blf_key . 72The stream of 32-bit words is encrypted in Electronic Codebook 73Mode (ECB) and 74.Pa datalen 75must be even. 76.Fn blf_dec 77is used for decrypting Blowfish encrypted blocks. 78.Pp 79The functions 80.Fn blf_ecb_encrypt 81and 82.Fn blf_ecb_decrypt 83are used for encrypting and decrypting octet streams in ECB mode. 84The functions 85.Fn blf_cbc_encrypt 86and 87.Fn blf_cbc_decrypt 88are used for encrypting and decrypting octet streams in 89Cipherblock Chaining Mode (CBC). 90.Pp 91The functions 92.Fn Blowfish_initstate , 93.Fn Blowfish_expand0state , 94.Fn Blowfish_expandstate , 95.Fn Blowfish_encipher 96and 97.Fn Blowfish_decipher 98are used for customization of the 99.Pa Blowfish 100cipher, e.g., for the blowfish password hashing function. 101.Sh SEE ALSO 102.Xr passwd 1 , 103.Xr crypt 3 , 104.Xr passwd 5 105.Sh AUTHORS 106.An Niels Provos Aq provos@physnet.uni-hamburg.de 107