mirror of https://gitee.com/openkylin/ppp.git
118 lines
3.3 KiB
C
118 lines
3.3 KiB
C
/*
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* chap-md5.c - New CHAP/MD5 implementation.
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*
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* Copyright (c) 2003 Paul Mackerras. 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. The name(s) of the authors of this software must not be used to
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* endorse or promote products derived from this software without
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* prior written permission.
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*
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* 3. Redistributions of any form whatsoever must retain the following
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* acknowledgment:
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* "This product includes software developed by Paul Mackerras
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* <paulus@samba.org>".
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*
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* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
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* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
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* SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
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* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
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* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#define RCSID "$Id: chap-md5.c,v 1.4 2004/11/09 22:39:25 paulus Exp $"
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#include <stdlib.h>
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#include <string.h>
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#include "pppd.h"
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#include "chap-new.h"
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#include "chap-md5.h"
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#include "magic.h"
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#include "md5.h"
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#define MD5_HASH_SIZE 16
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#define MD5_MIN_CHALLENGE 16
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#define MD5_MAX_CHALLENGE 24
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static void
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chap_md5_generate_challenge(unsigned char *cp)
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{
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int clen;
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clen = (int)(drand48() * (MD5_MAX_CHALLENGE - MD5_MIN_CHALLENGE))
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+ MD5_MIN_CHALLENGE;
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*cp++ = clen;
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random_bytes(cp, clen);
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}
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static int
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chap_md5_verify_response(int id, char *name,
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unsigned char *secret, int secret_len,
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unsigned char *challenge, unsigned char *response,
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char *message, int message_space)
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{
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MD5_CTX ctx;
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unsigned char idbyte = id;
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unsigned char hash[MD5_HASH_SIZE];
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int challenge_len, response_len;
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challenge_len = *challenge++;
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response_len = *response++;
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if (response_len == MD5_HASH_SIZE) {
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/* Generate hash of ID, secret, challenge */
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MD5_Init(&ctx);
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MD5_Update(&ctx, &idbyte, 1);
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MD5_Update(&ctx, secret, secret_len);
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MD5_Update(&ctx, challenge, challenge_len);
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MD5_Final(hash, &ctx);
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/* Test if our hash matches the peer's response */
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if (memcmp(hash, response, MD5_HASH_SIZE) == 0) {
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slprintf(message, message_space, "Access granted");
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return 1;
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}
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}
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slprintf(message, message_space, "Access denied");
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return 0;
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}
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static void
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chap_md5_make_response(unsigned char *response, int id, char *our_name,
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unsigned char *challenge, char *secret, int secret_len,
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unsigned char *private)
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{
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MD5_CTX ctx;
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unsigned char idbyte = id;
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int challenge_len = *challenge++;
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MD5_Init(&ctx);
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MD5_Update(&ctx, &idbyte, 1);
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MD5_Update(&ctx, (u_char *)secret, secret_len);
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MD5_Update(&ctx, challenge, challenge_len);
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MD5_Final(&response[1], &ctx);
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response[0] = MD5_HASH_SIZE;
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}
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static struct chap_digest_type md5_digest = {
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CHAP_MD5, /* code */
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chap_md5_generate_challenge,
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chap_md5_verify_response,
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chap_md5_make_response,
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NULL, /* check_success */
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NULL, /* handle_failure */
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};
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void
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chap_md5_init(void)
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{
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chap_register_digest(&md5_digest);
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}
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