130 lines
3.7 KiB
C
130 lines
3.7 KiB
C
/*
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* Copyright (c) 2001 Kungliga Tekniska Högskolan
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* (Royal Institute of Technology, Stockholm, Sweden).
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "krb_locl.h"
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__RCSID("$KTH-KRB: random_block.c,v 1.1 2001/08/26 01:46:51 assar Exp $"
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"$NetBSD: random_block.c,v 1.1.1.2 2002/09/12 12:22:10 joda Exp $");
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#ifdef HAVE_OPENSSL
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#include <openssl/rand.h>
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/* From openssl/crypto/rand/rand_lcl.h */
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#define ENTROPY_NEEDED 20
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static int
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seed_something(void)
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{
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int fd = -1;
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char buf[1024], seedfile[256];
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/* If there is a seed file, load it. But such a file cannot be trusted,
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so use 0 for the entropy estimate */
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if (RAND_file_name(seedfile, sizeof(seedfile))) {
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fd = open(seedfile, O_RDONLY);
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if (fd >= 0) {
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read(fd, buf, sizeof(buf));
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/* Use the full buffer anyway */
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RAND_add(buf, sizeof(buf), 0.0);
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} else
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seedfile[0] = '\0';
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} else
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seedfile[0] = '\0';
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/* Calling RAND_status() will try to use /dev/urandom if it exists so
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we do not have to deal with it. */
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if (RAND_status() != 1) {
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const char *p;
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/* Try using egd */
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p = krb_get_config_string("egd_socket");
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if (p != NULL)
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RAND_egd_bytes(p, ENTROPY_NEEDED);
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}
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if (RAND_status() == 1) {
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/* Update the seed file */
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if (seedfile[0])
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RAND_write_file(seedfile);
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return 0;
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} else
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return -1;
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}
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void
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krb_generate_random_block(void *buf, size_t len)
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{
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static int rng_initialized = 0;
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if (!rng_initialized) {
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if (seed_something()) {
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fprintf(stderr, "Could not initialize openssl rng\n");
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exit(1);
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}
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rng_initialized = 1;
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}
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RAND_bytes(buf, len);
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}
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#else /* !HAVE_OPENSSL */
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void
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krb_generate_random_block(void *buf, size_t len)
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{
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des_cblock key, out;
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static des_cblock counter;
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static des_key_schedule schedule;
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int i;
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static int initialized = 0;
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if(!initialized) {
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des_new_random_key(&key);
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des_set_key(&key, schedule);
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memset(&key, 0, sizeof(key));
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des_new_random_key(&counter);
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}
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while(len > 0) {
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des_ecb_encrypt(&counter, &out, schedule, DES_ENCRYPT);
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for(i = 7; i >=0; i--)
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if(counter[i]++)
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break;
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memcpy(buf, out, min(len, sizeof(out)));
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len -= min(len, sizeof(out));
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buf = (char*)buf + sizeof(out);
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}
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}
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#endif /* !HAVE_OPENSSL */
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