cipher-bf1.c revision 162852
1/* $OpenBSD: cipher-bf1.c,v 1.5 2006/08/03 03:34:42 deraadt Exp $ */ 2/* 3 * Copyright (c) 2003 Markus Friedl. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "includes.h" 27 28#include <sys/types.h> 29 30#include <openssl/evp.h> 31 32#include <stdarg.h> 33#include <string.h> 34 35#include "xmalloc.h" 36#include "log.h" 37 38#if OPENSSL_VERSION_NUMBER < 0x00906000L 39#define SSH_OLD_EVP 40#endif 41 42/* 43 * SSH1 uses a variation on Blowfish, all bytes must be swapped before 44 * and after encryption/decryption. Thus the swap_bytes stuff (yuk). 45 */ 46 47const EVP_CIPHER * evp_ssh1_bf(void); 48 49static void 50swap_bytes(const u_char *src, u_char *dst, int n) 51{ 52 u_char c[4]; 53 54 /* Process 4 bytes every lap. */ 55 for (n = n / 4; n > 0; n--) { 56 c[3] = *src++; 57 c[2] = *src++; 58 c[1] = *src++; 59 c[0] = *src++; 60 61 *dst++ = c[0]; 62 *dst++ = c[1]; 63 *dst++ = c[2]; 64 *dst++ = c[3]; 65 } 66} 67 68#ifdef SSH_OLD_EVP 69static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key, 70 const unsigned char *iv, int enc) 71{ 72 if (iv != NULL) 73 memcpy (&(ctx->oiv[0]), iv, 8); 74 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8); 75 if (key != NULL) 76 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx), 77 key); 78} 79#endif 80 81static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; 82 83static int 84bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) 85{ 86 int ret; 87 88 swap_bytes(in, out, len); 89 ret = (*orig_bf)(ctx, out, out, len); 90 swap_bytes(out, out, len); 91 return (ret); 92} 93 94const EVP_CIPHER * 95evp_ssh1_bf(void) 96{ 97 static EVP_CIPHER ssh1_bf; 98 99 memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); 100 orig_bf = ssh1_bf.do_cipher; 101 ssh1_bf.nid = NID_undef; 102#ifdef SSH_OLD_EVP 103 ssh1_bf.init = bf_ssh1_init; 104#endif 105 ssh1_bf.do_cipher = bf_ssh1_cipher; 106 ssh1_bf.key_len = 32; 107 return (&ssh1_bf); 108} 109