diff options
Diffstat (limited to 'cipher-aes.c')
| -rw-r--r-- | cipher-aes.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/cipher-aes.c b/cipher-aes.c new file mode 100644 index 0000000..87c7633 --- /dev/null +++ b/cipher-aes.c @@ -0,0 +1,161 @@ +/* + * Copyright (c) 2003 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include "includes.h" + +/* compatibility with old or broken OpenSSL versions */ +#include "openbsd-compat/openssl-compat.h" + +#ifdef USE_BUILTIN_RIJNDAEL +#include <sys/types.h> + +#include <openssl/evp.h> + +#include <stdarg.h> +#include <string.h> + +#include "rijndael.h" +#include "xmalloc.h" +#include "log.h" + +#define RIJNDAEL_BLOCKSIZE 16 +struct ssh_rijndael_ctx +{ + rijndael_ctx r_ctx; + u_char r_iv[RIJNDAEL_BLOCKSIZE]; +}; + +static int +ssh_rijndael_init(EVP_CIPHER_CTX *ctx, const u_char *key, const u_char *iv, + int enc) +{ + struct ssh_rijndael_ctx *c; + + if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { + c = xmalloc(sizeof(*c)); + EVP_CIPHER_CTX_set_app_data(ctx, c); + } + if (key != NULL) { + if (enc == -1) + enc = ctx->encrypt; + rijndael_set_key(&c->r_ctx, (u_char *)key, + 8*EVP_CIPHER_CTX_key_length(ctx), enc); + } + if (iv != NULL) + memcpy(c->r_iv, iv, RIJNDAEL_BLOCKSIZE); + return (1); +} + +static int +ssh_rijndael_cbc(EVP_CIPHER_CTX *ctx, u_char *dest, const u_char *src, + size_t len) +{ + struct ssh_rijndael_ctx *c; + u_char buf[RIJNDAEL_BLOCKSIZE]; + u_char *cprev, *cnow, *plain, *ivp; + int i, j, blocks = len / RIJNDAEL_BLOCKSIZE; + + if (len == 0) + return (1); + if (len % RIJNDAEL_BLOCKSIZE) + fatal("ssh_rijndael_cbc: bad len %d", len); + if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) == NULL) { + error("ssh_rijndael_cbc: no context"); + return (0); + } + if (ctx->encrypt) { + cnow = dest; + plain = (u_char *)src; + cprev = c->r_iv; + for (i = 0; i < blocks; i++, plain+=RIJNDAEL_BLOCKSIZE, + cnow+=RIJNDAEL_BLOCKSIZE) { + for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) + buf[j] = plain[j] ^ cprev[j]; + rijndael_encrypt(&c->r_ctx, buf, cnow); + cprev = cnow; + } + memcpy(c->r_iv, cprev, RIJNDAEL_BLOCKSIZE); + } else { + cnow = (u_char *) (src+len-RIJNDAEL_BLOCKSIZE); + plain = dest+len-RIJNDAEL_BLOCKSIZE; + + memcpy(buf, cnow, RIJNDAEL_BLOCKSIZE); + for (i = blocks; i > 0; i--, cnow-=RIJNDAEL_BLOCKSIZE, + plain-=RIJNDAEL_BLOCKSIZE) { + rijndael_decrypt(&c->r_ctx, cnow, plain); + ivp = (i == 1) ? c->r_iv : cnow-RIJNDAEL_BLOCKSIZE; + for (j = 0; j < RIJNDAEL_BLOCKSIZE; j++) + plain[j] ^= ivp[j]; + } + memcpy(c->r_iv, buf, RIJNDAEL_BLOCKSIZE); + } + return (1); +} + +static int +ssh_rijndael_cleanup(EVP_CIPHER_CTX *ctx) +{ + struct ssh_rijndael_ctx *c; + + if ((c = EVP_CIPHER_CTX_get_app_data(ctx)) != NULL) { + memset(c, 0, sizeof(*c)); + free(c); + EVP_CIPHER_CTX_set_app_data(ctx, NULL); + } + return (1); +} + +void +ssh_rijndael_iv(EVP_CIPHER_CTX *evp, int doset, u_char * iv, u_int len) +{ + struct ssh_rijndael_ctx *c; + + if ((c = EVP_CIPHER_CTX_get_app_data(evp)) == NULL) + fatal("ssh_rijndael_iv: no context"); + if (doset) + memcpy(c->r_iv, iv, len); + else + memcpy(iv, c->r_iv, len); +} + +const EVP_CIPHER * +evp_rijndael(void) +{ + static EVP_CIPHER rijndal_cbc; + + memset(&rijndal_cbc, 0, sizeof(EVP_CIPHER)); + rijndal_cbc.nid = NID_undef; + rijndal_cbc.block_size = RIJNDAEL_BLOCKSIZE; + rijndal_cbc.iv_len = RIJNDAEL_BLOCKSIZE; + rijndal_cbc.key_len = 16; + rijndal_cbc.init = ssh_rijndael_init; + rijndal_cbc.cleanup = ssh_rijndael_cleanup; + rijndal_cbc.do_cipher = ssh_rijndael_cbc; +#ifndef SSH_OLD_EVP + rijndal_cbc.flags = EVP_CIPH_CBC_MODE | EVP_CIPH_VARIABLE_LENGTH | + EVP_CIPH_ALWAYS_CALL_INIT | EVP_CIPH_CUSTOM_IV; +#endif + return (&rijndal_cbc); +} +#endif /* USE_BUILTIN_RIJNDAEL */ |