cipher-bf1.c revision 124208
1124208Sdes/* 2124208Sdes * Copyright (c) 2003 Markus Friedl. All rights reserved. 3124208Sdes * 4124208Sdes * Redistribution and use in source and binary forms, with or without 5124208Sdes * modification, are permitted provided that the following conditions 6124208Sdes * are met: 7124208Sdes * 1. Redistributions of source code must retain the above copyright 8124208Sdes * notice, this list of conditions and the following disclaimer. 9124208Sdes * 2. Redistributions in binary form must reproduce the above copyright 10124208Sdes * notice, this list of conditions and the following disclaimer in the 11124208Sdes * documentation and/or other materials provided with the distribution. 12124208Sdes * 13124208Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14124208Sdes * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15124208Sdes * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16124208Sdes * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17124208Sdes * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18124208Sdes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19124208Sdes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20124208Sdes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21124208Sdes * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22124208Sdes * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23124208Sdes */ 24124208Sdes 25124208Sdes#include "includes.h" 26124208SdesRCSID("$OpenBSD: cipher-bf1.c,v 1.1 2003/05/15 03:08:29 markus Exp $"); 27124208Sdes 28124208Sdes#include <openssl/evp.h> 29124208Sdes#include "xmalloc.h" 30124208Sdes#include "log.h" 31124208Sdes 32124208Sdes#if OPENSSL_VERSION_NUMBER < 0x00906000L 33124208Sdes#define SSH_OLD_EVP 34124208Sdes#endif 35124208Sdes 36124208Sdes/* 37124208Sdes * SSH1 uses a variation on Blowfish, all bytes must be swapped before 38124208Sdes * and after encryption/decryption. Thus the swap_bytes stuff (yuk). 39124208Sdes */ 40124208Sdes 41124208Sdesconst EVP_CIPHER * evp_ssh1_bf(void); 42124208Sdes 43124208Sdesstatic void 44124208Sdesswap_bytes(const u_char *src, u_char *dst, int n) 45124208Sdes{ 46124208Sdes u_char c[4]; 47124208Sdes 48124208Sdes /* Process 4 bytes every lap. */ 49124208Sdes for (n = n / 4; n > 0; n--) { 50124208Sdes c[3] = *src++; 51124208Sdes c[2] = *src++; 52124208Sdes c[1] = *src++; 53124208Sdes c[0] = *src++; 54124208Sdes 55124208Sdes *dst++ = c[0]; 56124208Sdes *dst++ = c[1]; 57124208Sdes *dst++ = c[2]; 58124208Sdes *dst++ = c[3]; 59124208Sdes } 60124208Sdes} 61124208Sdes 62124208Sdes#ifdef SSH_OLD_EVP 63124208Sdesstatic void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key, 64124208Sdes const unsigned char *iv, int enc) 65124208Sdes{ 66124208Sdes if (iv != NULL) 67124208Sdes memcpy (&(ctx->oiv[0]), iv, 8); 68124208Sdes memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8); 69124208Sdes if (key != NULL) 70124208Sdes BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx), 71124208Sdes key); 72124208Sdes} 73124208Sdes#endif 74124208Sdes 75124208Sdesstatic int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; 76124208Sdes 77124208Sdesstatic int 78124208Sdesbf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) 79124208Sdes{ 80124208Sdes int ret; 81124208Sdes 82124208Sdes swap_bytes(in, out, len); 83124208Sdes ret = (*orig_bf)(ctx, out, out, len); 84124208Sdes swap_bytes(out, out, len); 85124208Sdes return (ret); 86124208Sdes} 87124208Sdes 88124208Sdesconst EVP_CIPHER * 89124208Sdesevp_ssh1_bf(void) 90124208Sdes{ 91124208Sdes static EVP_CIPHER ssh1_bf; 92124208Sdes 93124208Sdes memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); 94124208Sdes orig_bf = ssh1_bf.do_cipher; 95124208Sdes ssh1_bf.nid = NID_undef; 96124208Sdes#ifdef SSH_OLD_EVP 97124208Sdes ssh1_bf.init = bf_ssh1_init; 98124208Sdes#endif 99124208Sdes ssh1_bf.do_cipher = bf_ssh1_cipher; 100124208Sdes ssh1_bf.key_len = 32; 101124208Sdes return (&ssh1_bf); 102124208Sdes} 103