/* * Copyright 1997 Niels Provos * 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Niels Provos. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * 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. */ /* * cookie.c: * cookie generation */ #ifndef lint static char rcsid[] = "$Id: cookie.c,v 1.1 1998/11/14 23:37:22 deraadt Exp $"; #endif #define _COOKIE_C_ #include #include #include #include #include "state.h" #include "cookie.h" void reset_secret(void) { secret_generate(rsecret, SECRET_SIZE); } int secret_generate(u_int8_t *secret, u_int16_t size) { int i = 0; long tmp = 0; while(size > 0) { size--; if (i++ % 4 == 0) tmp = arc4random(); secret[size] = tmp & 0xFF; tmp = tmp >> 8; } return 1; } int cookie_generate(struct stateob *st, u_int8_t *cookie, u_int16_t size, u_int8_t *data, u_int16_t dsize) { MD5_CTX ctx; u_int8_t digest[16]; u_int8_t tmpsecret[SECRET_SIZE], *secret; if (st->initiator) { secret = tmpsecret; secret_generate(tmpsecret, SECRET_SIZE); /* New secret each CookieReq */ } else secret = rsecret; /* Generate a cookie which depends on both parties and on local * information, which is fast computed. */ MD5Init(&ctx); MD5Update(&ctx, st->address, strlen(st->address)); MD5Update(&ctx, (u_int8_t *)&st->port, sizeof(st->port)); MD5Update(&ctx, (u_int8_t *)&st->counter, sizeof(st->counter)); MD5Update(&ctx, secret, SECRET_SIZE); MD5Update(&ctx, st->icookie, COOKIE_SIZE); /* For the responder cookie we also hash the schemes */ if (data != NULL && dsize) MD5Update(&ctx, data, dsize); MD5Final(digest, &ctx); bcopy(digest, cookie, size); return 1; }