1.\" $OpenBSD: blowfish.3,v 1.24 2021/11/29 01:04:45 djm 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. The name of the author may not be used to endorse or promote products 15.\" derived from this software without specific prior written permission. 16.\" 17.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27.\" 28.\" Manual page, using -mandoc macros 29.\" 30.Dd $Mdocdate: November 29 2021 $ 31.Dt BLF_KEY 3 32.Os 33.Sh NAME 34.Nm blf_key , 35.Nm blf_enc , 36.Nm blf_dec , 37.Nm blf_ecb_encrypt , 38.Nm blf_ecb_decrypt , 39.Nm blf_cbc_encrypt , 40.Nm blf_cbc_decrypt 41.Nd Blowfish encryption 42.Sh SYNOPSIS 43.In blf.h 44.Ft void 45.Fn blf_key "blf_ctx *state" "const u_int8_t *key" "u_int16_t keylen" 46.Ft void 47.Fn blf_enc "blf_ctx *state" "u_int32_t *data" "u_int16_t blocks" 48.Ft void 49.Fn blf_dec "blf_ctx *state" "u_int32_t *data" "u_int16_t blocks" 50.Ft void 51.Fn blf_ecb_encrypt "blf_ctx *state" "u_int8_t *data" "u_int32_t datalen" 52.Ft void 53.Fn blf_ecb_decrypt "blf_ctx *state" "u_int8_t *data" "u_int32_t datalen" 54.Ft void 55.Fn blf_cbc_encrypt "blf_ctx *state" "u_int8_t *iv" "u_int8_t *data" "u_int32_t datalen" 56.Ft void 57.Fn blf_cbc_decrypt "blf_ctx *state" "u_int8_t *iv" "u_int8_t *data" "u_int32_t datalen" 58.Sh DESCRIPTION 59.Em Blowfish 60is a fast unpatented block cipher designed by Bruce Schneier. 61It basically consists of a 16-round Feistel network. 62The block size is 64 bits and the maximum key size is 448 bits. 63.Pp 64The 65.Fn blf_key 66function initializes the 4 8-bit S-boxes and the 18 Subkeys with 67the hexadecimal digits of Pi. 68The key is used for further randomization. 69The first argument to 70.Fn blf_enc 71is the initialized state derived from 72.Fn blf_key . 73The stream of 32-bit words is encrypted in Electronic Codebook 74Mode (ECB) and 75.Fa blocks 76is the number of 64-bit blocks in the stream. 77.Fn blf_dec 78is used for decrypting Blowfish encrypted blocks. 79.Pp 80The functions 81.Fn blf_ecb_encrypt 82and 83.Fn blf_ecb_decrypt 84are used for encrypting and decrypting octet streams in ECB mode. 85The functions 86.Fn blf_cbc_encrypt 87and 88.Fn blf_cbc_decrypt 89are used for encrypting and decrypting octet streams in 90Cipherblock Chaining Mode (CBC). 91For these functions 92.Fa datalen 93specifies the number of octets of data to encrypt or decrypt. 94It must be a multiple of 8 (64-bit block). 95The initialisation vector 96.Fa iv 97points to an 8-byte buffer. 98.Sh SEE ALSO 99.Xr passwd 1 , 100.Xr crypt 3 , 101.Xr passwd 5 102.Sh AUTHORS 103.An Niels Provos Aq Mt provos@physnet.uni-hamburg.de 104