diff options
Diffstat (limited to 'cipher-bf1.c')
-rw-r--r-- | cipher-bf1.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/cipher-bf1.c b/cipher-bf1.c new file mode 100644 index 00000000..64578bae --- /dev/null +++ b/cipher-bf1.c @@ -0,0 +1,97 @@ +/* + * 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" +RCSID("$OpenBSD: cipher-bf1.c,v 1.1 2003/05/15 03:08:29 markus Exp $"); + +#include <openssl/evp.h> +#include "xmalloc.h" +#include "log.h" +/* + * SSH1 uses a variation on Blowfish, all bytes must be swapped before + * and after encryption/decryption. Thus the swap_bytes stuff (yuk). + */ + +const EVP_CIPHER * evp_ssh1_bf(void); + +static void +swap_bytes(const u_char *src, u_char *dst, int n) +{ + u_char c[4]; + + /* Process 4 bytes every lap. */ + for (n = n / 4; n > 0; n--) { + c[3] = *src++; + c[2] = *src++; + c[1] = *src++; + c[0] = *src++; + + *dst++ = c[0]; + *dst++ = c[1]; + *dst++ = c[2]; + *dst++ = c[3]; + } +} + +#ifdef SSH_OLD_EVP +static void bf_ssh1_init (EVP_CIPHER_CTX * ctx, const unsigned char *key, + const unsigned char *iv, int enc) +{ + if (iv != NULL) + memcpy (&(ctx->oiv[0]), iv, 8); + memcpy (&(ctx->iv[0]), &(ctx->oiv[0]), 8); + if (key != NULL) + BF_set_key (&(ctx->c.bf_ks), EVP_CIPHER_CTX_key_length (ctx), + key); +} +#endif + +static int (*orig_bf)(EVP_CIPHER_CTX *, u_char *, const u_char *, u_int) = NULL; + +static int +bf_ssh1_cipher(EVP_CIPHER_CTX *ctx, u_char *out, const u_char *in, u_int len) +{ + int ret; + + swap_bytes(in, out, len); + ret = (*orig_bf)(ctx, out, out, len); + swap_bytes(out, out, len); + return (ret); +} + +const EVP_CIPHER * +evp_ssh1_bf(void) +{ + static EVP_CIPHER ssh1_bf; + + memcpy(&ssh1_bf, EVP_bf_cbc(), sizeof(EVP_CIPHER)); + orig_bf = ssh1_bf.do_cipher; + ssh1_bf.nid = NID_undef; +#ifdef SSH_OLD_EVP + ssh1_bf.init = bf_ssh1_init; +#endif + ssh1_bf.do_cipher = bf_ssh1_cipher; + ssh1_bf.key_len = 32; + return (&ssh1_bf); +} |