1295367Sdes/* $OpenBSD: cipher-3des1.c,v 1.12 2015/01/14 10:24:42 markus Exp $ */ 2124208Sdes/* 3124208Sdes * Copyright (c) 2003 Markus Friedl. All rights reserved. 4124208Sdes * 5295367Sdes * Permission to use, copy, modify, and distribute this software for any 6295367Sdes * purpose with or without fee is hereby granted, provided that the above 7295367Sdes * copyright notice and this permission notice appear in all copies. 8124208Sdes * 9124208Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 10124208Sdes * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 11124208Sdes * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 12124208Sdes * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 13124208Sdes * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 14124208Sdes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 15124208Sdes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 16124208Sdes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 17124208Sdes * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 18124208Sdes * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 19124208Sdes */ 20124208Sdes 21124208Sdes#include "includes.h" 22124208Sdes 23162852Sdes#include <sys/types.h> 24295367Sdes#include <string.h> 25124208Sdes#include <openssl/evp.h> 26162852Sdes 27295367Sdes#include "ssherr.h" 28162852Sdes 29124208Sdes/* 30124208Sdes * This is used by SSH1: 31124208Sdes * 32124208Sdes * What kind of triple DES are these 2 routines? 33124208Sdes * 34124208Sdes * Why is there a redundant initialization vector? 35124208Sdes * 36124208Sdes * If only iv3 was used, then, this would till effect have been 37124208Sdes * outer-cbc. However, there is also a private iv1 == iv2 which 38124208Sdes * perhaps makes differential analysis easier. On the other hand, the 39124208Sdes * private iv1 probably makes the CRC-32 attack ineffective. This is a 40124208Sdes * result of that there is no longer any known iv1 to use when 41124208Sdes * choosing the X block. 42124208Sdes */ 43124208Sdesstruct ssh1_3des_ctx 44124208Sdes{ 45124208Sdes EVP_CIPHER_CTX k1, k2, k3; 46124208Sdes}; 47124208Sdes 48124208Sdesconst EVP_CIPHER * evp_ssh1_3des(void); 49295367Sdesint ssh1_3des_iv(EVP_CIPHER_CTX *, int, u_char *, int); 50124208Sdes 51124208Sdesstatic int 52124208Sdesssh1_3des_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, 53124208Sdes int enc) 54124208Sdes{ 55124208Sdes struct ssh1_3des_ctx *c; 56124208Sdes u_char *k1, *k2, *k3; 57124208Sdes 58124208Sdes if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 59295367Sdes if ((c = calloc(1, sizeof(*c))) == NULL) 60295367Sdes return 0; 61124208Sdes EVP_CIPHER_CTX_set_app_data(ctx, c); 62124208Sdes } 63124208Sdes if (key == NULL) 64295367Sdes return 1; 65124208Sdes if (enc == -1) 66124208Sdes enc = ctx->encrypt; 67124208Sdes k1 = k2 = k3 = (u_char *) key; 68124208Sdes k2 += 8; 69124208Sdes if (EVP_CIPHER_CTX_key_length(ctx) >= 16+8) { 70124208Sdes if (enc) 71124208Sdes k3 += 16; 72124208Sdes else 73124208Sdes k1 += 16; 74124208Sdes } 75124208Sdes EVP_CIPHER_CTX_init(&c->k1); 76124208Sdes EVP_CIPHER_CTX_init(&c->k2); 77124208Sdes EVP_CIPHER_CTX_init(&c->k3); 78124208Sdes if (EVP_CipherInit(&c->k1, EVP_des_cbc(), k1, NULL, enc) == 0 || 79124208Sdes EVP_CipherInit(&c->k2, EVP_des_cbc(), k2, NULL, !enc) == 0 || 80124208Sdes EVP_CipherInit(&c->k3, EVP_des_cbc(), k3, NULL, enc) == 0) { 81264377Sdes explicit_bzero(c, sizeof(*c)); 82255767Sdes free(c); 83124208Sdes EVP_CIPHER_CTX_set_app_data(ctx, NULL); 84295367Sdes return 0; 85124208Sdes } 86295367Sdes return 1; 87124208Sdes} 88124208Sdes 89124208Sdesstatic int 90295367Sdesssh1_3des_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, size_t len) 91124208Sdes{ 92124208Sdes struct ssh1_3des_ctx *c; 93124208Sdes 94295367Sdes if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) 95295367Sdes return 0; 96124208Sdes if (EVP_Cipher(&c->k1, dest, (u_char *)src, len) == 0 || 97124208Sdes EVP_Cipher(&c->k2, dest, dest, len) == 0 || 98124208Sdes EVP_Cipher(&c->k3, dest, dest, len) == 0) 99295367Sdes return 0; 100295367Sdes return 1; 101124208Sdes} 102124208Sdes 103124208Sdesstatic int 104124208Sdesssh1_3des_cleanup(EVP_CIPHER_CTX *ctx) 105124208Sdes{ 106124208Sdes struct ssh1_3des_ctx *c; 107124208Sdes 108124208Sdes if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { 109126274Sdes EVP_CIPHER_CTX_cleanup(&c->k1); 110126274Sdes EVP_CIPHER_CTX_cleanup(&c->k2); 111126274Sdes EVP_CIPHER_CTX_cleanup(&c->k3); 112264377Sdes explicit_bzero(c, sizeof(*c)); 113255767Sdes free(c); 114124208Sdes EVP_CIPHER_CTX_set_app_data(ctx, NULL); 115124208Sdes } 116295367Sdes return 1; 117124208Sdes} 118124208Sdes 119295367Sdesint 120124208Sdesssh1_3des_iv(EVP_CIPHER_CTX *evp, int doset, u_char *iv, int len) 121124208Sdes{ 122124208Sdes struct ssh1_3des_ctx *c; 123124208Sdes 124124208Sdes if (len != 24) 125295367Sdes return SSH_ERR_INVALID_ARGUMENT; 126124208Sdes if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) 127295367Sdes return SSH_ERR_INTERNAL_ERROR; 128124208Sdes if (doset) { 129124208Sdes memcpy(c->k1.iv, iv, 8); 130124208Sdes memcpy(c->k2.iv, iv + 8, 8); 131124208Sdes memcpy(c->k3.iv, iv + 16, 8); 132124208Sdes } else { 133124208Sdes memcpy(iv, c->k1.iv, 8); 134124208Sdes memcpy(iv + 8, c->k2.iv, 8); 135124208Sdes memcpy(iv + 16, c->k3.iv, 8); 136124208Sdes } 137295367Sdes return 0; 138124208Sdes} 139124208Sdes 140124208Sdesconst EVP_CIPHER * 141124208Sdesevp_ssh1_3des(void) 142124208Sdes{ 143124208Sdes static EVP_CIPHER ssh1_3des; 144124208Sdes 145295367Sdes memset(&ssh1_3des, 0, sizeof(ssh1_3des)); 146124208Sdes ssh1_3des.nid = NID_undef; 147124208Sdes ssh1_3des.block_size = 8; 148124208Sdes ssh1_3des.iv_len = 0; 149124208Sdes ssh1_3des.key_len = 16; 150124208Sdes ssh1_3des.init = ssh1_3des_init; 151124208Sdes ssh1_3des.cleanup = ssh1_3des_cleanup; 152124208Sdes ssh1_3des.do_cipher = ssh1_3des_cbc; 153124208Sdes ssh1_3des.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH; 154295367Sdes return &ssh1_3des; 155124208Sdes} 156