1 /* $OpenBSD: cipher-bf1.c,v 1.6 2010/10/01 23:05:32 djm 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 #include "openbsd-compat/openssl-compat.h" 39 40 /* 41 * SSH1 uses a variation on Blowfish, all bytes must be swapped before 42 * and after encryption/decryption. Thus the swap_bytes stuff (yuk). 43 */ 44 45 const EVP_CIPHER * evp_ssh1_bf(void); 46 47 static void 48 swap_bytes(const u_char *src, u_char *dst, int n) 49 { 50 u_char c[4]; 51 52 /* Process 4 bytes every lap. */ 53 for (n = n / 4; n > 0; n--) { 54 c[3] = *src++; 55 c[2] = *src++; 56 c[1] = *src++; 57 c[0] = *src++; 58 59 *dst++ = c[0]; 60 *dst++ = c[1]; 61 *dst++ = c[2]; 62 *dst++ = c[3]; 63 } 64 } 65 66 #ifdef SSH_OLD_EVP 67 static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key, 68 const unsigned char *iv, int enc) 69 { 70 if (iv != NULL) 71 memcpy (&(ctx->oiv[0]), iv, 8); 72 memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8); 73 if (key != NULL) 74 BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx), 75 key); 76 } 77 #endif 78 79 static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, 80 const u_char *, LIBCRYPTO_EVP_INL_TYPE) = NULL; 81 82 static int 83 bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, 84 LIBCRYPTO_EVP_INL_TYPE 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 94 const EVP_CIPHER * 95 evp_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
