cipher-aes.c revision 162852
136865Sdfr/* 236865Sdfr * Copyright (c) 2003 Markus Friedl. All rights reserved. 336865Sdfr * 436865Sdfr * Redistribution and use in source and binary forms, with or without 536865Sdfr * modification, are permitted provided that the following conditions 636865Sdfr * are met: 736865Sdfr * 1. Redistributions of source code must retain the above copyright 836865Sdfr * notice, this list of conditions and the following disclaimer. 936865Sdfr * 2. Redistributions in binary form must reproduce the above copyright 1036865Sdfr * notice, this list of conditions and the following disclaimer in the 1136865Sdfr * documentation and/or other materials provided with the distribution. 1236865Sdfr * 1336865Sdfr * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1436865Sdfr * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1536865Sdfr * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1636865Sdfr * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1736865Sdfr * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1836865Sdfr * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 1936865Sdfr * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2036865Sdfr * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2136865Sdfr * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2236865Sdfr * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2336865Sdfr */ 2436865Sdfr 2536865Sdfr#include "includes.h" 2636865Sdfr 2736865Sdfr/* compatibility with old or broken OpenSSL versions */ 2836865Sdfr#include "openbsd-compat/openssl-compat.h" 2936865Sdfr 3036865Sdfr#ifdef USE_BUILTIN_RIJNDAEL 3136865Sdfr#include <sys/types.h> 3236865Sdfr 3336865Sdfr#include <openssl/evp.h> 3436865Sdfr 3536865Sdfr#include <stdarg.h> 3636865Sdfr#include <string.h> 3736865Sdfr 3836865Sdfr#include "rijndael.h" 3936865Sdfr#include "xmalloc.h" 4036865Sdfr#include "log.h" 4150477Speter 4236865Sdfr#define RIJNDAEL_BLOCKSIZE 16 4336865Sdfrstruct ssh_rijndael_ctx 4436865Sdfr{ 4536865Sdfr rijndael_ctx r_ctx; 4636865Sdfr u_char r_iv[RIJNDAEL_BLOCKSIZE]; 4736865Sdfr}; 4836865Sdfr 4936865Sdfrconst EVP_CIPHER * evp_rijndael(void); 5036865Sdfrvoid ssh_rijndael_iv(EVP_CIPHER_CTX *, int, u_char *, u_int); 5136865Sdfr 5236865Sdfrstatic int 5336865Sdfrssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, 5436865Sdfr int enc) 5536865Sdfr{ 5636865Sdfr struct ssh_rijndael_ctx *c; 5736865Sdfr 5836865Sdfr if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 5936865Sdfr c = xmalloc(sizeof(*c)); 6036865Sdfr EVP_CIPHER_CTX_set_app_data(ctx, c); 6136865Sdfr } 6236865Sdfr if (key != NULL) { 6336865Sdfr if (enc == -1) 6436865Sdfr enc = ctx->encrypt; 6536865Sdfr rijndael_set_key(&c->r_ctx, (u_char *)key, 6636865Sdfr 8*EVP_CIPHER_CTX_key_length(ctx), enc); 6736865Sdfr } 6836865Sdfr if (iv != NULL) 6936865Sdfr memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); 70118239Speter return (1); 71118239Speter} 7236865Sdfr 7336865Sdfrstatic int 7436865Sdfrssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, 7536865Sdfr u_int len) 7660041Sphk{ 7736865Sdfr struct ssh_rijndael_ctx *c; 7885201Smp u_char buf[RIJNDAEL_BLOCKSIZE]; 7985201Smp u_char *cprev, *cnow, *plain, *ivp; 8067365Sjhb int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; 8136865Sdfr 8236865Sdfr if (len == 0) 8336865Sdfr return (1); 84119563Salc if (len % RIJNDAEL_BLOCKSIZE) 85119563Salc fatal("ssh_rijndael_cbc: bad len %d", len); 8636865Sdfr if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { 8754207Speter error("ssh_rijndael_cbc: no context"); 8836865Sdfr return (0); 8936865Sdfr } 9036865Sdfr if (ctx->encrypt) { 9141499Sdfr cnow = dest; 9297397Sbenno plain = (u_char *)src; 9336865Sdfr cprev = c->r_iv; 9436865Sdfr for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, 9578342Sbenno cnow+=RIJNDAEL_BLOCKSIZE) { 9678342Sbenno for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) 9736865Sdfr buf[j] = plain[j] ^ cprev[j]; 9836865Sdfr rijndael_encrypt(&c->r_ctx, buf, cnow); 9936865Sdfr cprev = cnow; 10036865Sdfr } 10136865Sdfr memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); 10236865Sdfr } else { 10336865Sdfr cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); 10436865Sdfr plain = dest+len-RIJNDAEL_BLOCKSIZE; 10536865Sdfr 106119563Salc memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); 107119563Salc for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, 108119563Salc plain-=RIJNDAEL_BLOCKSIZE) { 10936865Sdfr rijndael_decrypt(&c->r_ctx, cnow, plain); 110119563Salc ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; 111119563Salc for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) 112119563Salc plain[j] ^= ivp[j]; 113119563Salc } 114119563Salc memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); 115119563Salc } 116119563Salc return (1); 117119563Salc} 118119563Salc 119119563Salcstatic int 120119563Salcssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) 12136865Sdfr{ 12236865Sdfr struct ssh_rijndael_ctx *c; 12336865Sdfr 12436865Sdfr if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { 12536865Sdfr memset(c, 0, sizeof(*c)); 12690361Sjulian xfree(c); 12736865Sdfr EVP_CIPHER_CTX_set_app_data(ctx, NULL); 12884977Sbenno } 12984977Sbenno return (1); 13084977Sbenno} 13190643Sbenno 13284977Sbennovoid 13391467Sbennossh_rijndael_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len) 13490643Sbenno{ 13584977Sbenno struct ssh_rijndael_ctx *c; 13684977Sbenno 13784977Sbenno if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) 13884977Sbenno fatal("ssh_rijndael_iv: no context"); 13984977Sbenno if (doset) 14084977Sbenno memcpy(c->r_iv, iv, len); 14184977Sbenno else 14291467Sbenno memcpy(iv, c->r_iv, len); 14391467Sbenno} 14490643Sbenno 14584977Sbennoconst EVP_CIPHER * 14690643Sbennoevp_rijndael(void) 14790643Sbenno{ 14884977Sbenno static EVP_CIPHER rijndal_cbc; 14984977Sbenno 15090643Sbenno memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); 15184977Sbenno rijndal_cbc.nid = NID_undef; 15284977Sbenno rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; 15384977Sbenno rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; 15490643Sbenno rijndal_cbc.key_len = 16; 15590643Sbenno rijndal_cbc.init = ssh_rijndael_init; 15684977Sbenno rijndal_cbc.cleanup = ssh_rijndael_cleanup; 15797397Sbenno rijndal_cbc.do_cipher = ssh_rijndael_cbc; 15897397Sbenno#ifndef SSH_OLD_EVP 15997397Sbenno rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | 16097397Sbenno EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; 16190643Sbenno#endif 16290643Sbenno return (&rijndal_cbc); 16390643Sbenno} 16490643Sbenno#endif /* USE_BUILTIN_RIJNDAEL */ 16591467Sbenno