1254721Semaste/* 2254721Semaste * chap-md5.c - New CHAP/MD5 implementation. 3254721Semaste * 4254721Semaste * Copyright (c) 2003 Paul Mackerras. All rights reserved. 5254721Semaste * 6254721Semaste * Redistribution and use in source and binary forms, with or without 7254721Semaste * modification, are permitted provided that the following conditions 8254721Semaste * are met: 9254721Semaste * 10254721Semaste * 1. Redistributions of source code must retain the above copyright 11254721Semaste * notice, this list of conditions and the following disclaimer. 12254721Semaste * 13254721Semaste * 2. The name(s) of the authors of this software must not be used to 14254721Semaste * endorse or promote products derived from this software without 15254721Semaste * prior written permission. 16254721Semaste * 17254721Semaste * 3. Redistributions of any form whatsoever must retain the following 18254721Semaste * acknowledgment: 19254721Semaste * "This product includes software developed by Paul Mackerras 20254721Semaste * <paulus@samba.org>". 21254721Semaste * 22254721Semaste * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO 23254721Semaste * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 24254721Semaste * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY 25254721Semaste * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 26254721Semaste * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN 27254721Semaste * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING 28254721Semaste * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 29254721Semaste */ 30254721Semaste 31254721Semaste#include "netif/ppp/ppp_opts.h" 32254721Semaste#if PPP_SUPPORT && CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */ 33254721Semaste 34254721Semaste#if 0 /* UNUSED */ 35254721Semaste#include <stdlib.h> 36254721Semaste#include <string.h> 37254721Semaste#endif /* UNUSED */ 38254721Semaste 39254721Semaste#include "netif/ppp/ppp_impl.h" 40254721Semaste 41254721Semaste#include "netif/ppp/chap-new.h" 42254721Semaste#include "netif/ppp/chap-md5.h" 43254721Semaste#include "netif/ppp/magic.h" 44254721Semaste#include "netif/ppp/pppcrypt.h" 45254721Semaste 46254721Semaste#define MD5_HASH_SIZE 16 47254721Semaste#define MD5_MIN_CHALLENGE 17 48254721Semaste#define MD5_MAX_CHALLENGE 24 49254721Semaste#define MD5_MIN_MAX_POWER_OF_TWO_CHALLENGE 3 /* 2^3-1 = 7, 17+7 = 24 */ 50254721Semaste 51254721Semaste#if PPP_SERVER 52254721Semastestatic void chap_md5_generate_challenge(ppp_pcb *pcb, unsigned char *cp) { 53254721Semaste int clen; 54254721Semaste LWIP_UNUSED_ARG(pcb); 55254721Semaste 56254721Semaste clen = MD5_MIN_CHALLENGE + magic_pow(MD5_MIN_MAX_POWER_OF_TWO_CHALLENGE); 57254721Semaste *cp++ = clen; 58254721Semaste magic_random_bytes(cp, clen); 59254721Semaste} 60254721Semaste 61254721Semastestatic int chap_md5_verify_response(ppp_pcb *pcb, int id, const char *name, 62254721Semaste const unsigned char *secret, int secret_len, 63254721Semaste const unsigned char *challenge, const unsigned char *response, 64254721Semaste char *message, int message_space) { 65254721Semaste lwip_md5_context ctx; 66254721Semaste unsigned char idbyte = id; 67254721Semaste unsigned char hash[MD5_HASH_SIZE]; 68254721Semaste int challenge_len, response_len; 69254721Semaste LWIP_UNUSED_ARG(name); 70254721Semaste LWIP_UNUSED_ARG(pcb); 71254721Semaste 72254721Semaste challenge_len = *challenge++; 73254721Semaste response_len = *response++; 74254721Semaste if (response_len == MD5_HASH_SIZE) { 75254721Semaste /* Generate hash of ID, secret, challenge */ 76254721Semaste lwip_md5_init(&ctx); 77254721Semaste lwip_md5_starts(&ctx); 78254721Semaste lwip_md5_update(&ctx, &idbyte, 1); 79254721Semaste lwip_md5_update(&ctx, secret, secret_len); 80254721Semaste lwip_md5_update(&ctx, challenge, challenge_len); 81254721Semaste lwip_md5_finish(&ctx, hash); 82254721Semaste lwip_md5_free(&ctx); 83254721Semaste 84254721Semaste /* Test if our hash matches the peer's response */ 85254721Semaste if (memcmp(hash, response, MD5_HASH_SIZE) == 0) { 86254721Semaste ppp_slprintf(message, message_space, "Access granted"); 87254721Semaste return 1; 88254721Semaste } 89254721Semaste } 90254721Semaste ppp_slprintf(message, message_space, "Access denied"); 91254721Semaste return 0; 92254721Semaste} 93254721Semaste#endif /* PPP_SERVER */ 94254721Semaste 95254721Semastestatic void chap_md5_make_response(ppp_pcb *pcb, unsigned char *response, int id, const char *our_name, 96254721Semaste const unsigned char *challenge, const char *secret, int secret_len, 97254721Semaste unsigned char *private_) { 98254721Semaste lwip_md5_context ctx; 99254721Semaste unsigned char idbyte = id; 100254721Semaste int challenge_len = *challenge++; 101254721Semaste LWIP_UNUSED_ARG(our_name); 102254721Semaste LWIP_UNUSED_ARG(private_); 103254721Semaste LWIP_UNUSED_ARG(pcb); 104254721Semaste 105254721Semaste lwip_md5_init(&ctx); 106254721Semaste lwip_md5_starts(&ctx); 107254721Semaste lwip_md5_update(&ctx, &idbyte, 1); 108254721Semaste lwip_md5_update(&ctx, (const u_char *)secret, secret_len); 109254721Semaste lwip_md5_update(&ctx, challenge, challenge_len); 110254721Semaste lwip_md5_finish(&ctx, &response[1]); 111254721Semaste lwip_md5_free(&ctx); 112254721Semaste response[0] = MD5_HASH_SIZE; 113254721Semaste} 114254721Semaste 115254721Semasteconst struct chap_digest_type md5_digest = { 116254721Semaste CHAP_MD5, /* code */ 117254721Semaste#if PPP_SERVER 118254721Semaste chap_md5_generate_challenge, 119254721Semaste chap_md5_verify_response, 120254721Semaste#endif /* PPP_SERVER */ 121254721Semaste chap_md5_make_response, 122254721Semaste NULL, /* check_success */ 123254721Semaste NULL, /* handle_failure */ 124254721Semaste}; 125254721Semaste 126254721Semaste#endif /* PPP_SUPPORT && CHAP_SUPPORT */ 127254721Semaste