1*6d49e1aeSJan Lentfer /* 2*6d49e1aeSJan Lentfer * MSCHAPV2 (RFC 2759) 3*6d49e1aeSJan Lentfer * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi> 4*6d49e1aeSJan Lentfer * 5*6d49e1aeSJan Lentfer * This program is free software; you can redistribute it and/or modify 6*6d49e1aeSJan Lentfer * it under the terms of the GNU General Public License version 2 as 7*6d49e1aeSJan Lentfer * published by the Free Software Foundation. 8*6d49e1aeSJan Lentfer * 9*6d49e1aeSJan Lentfer * Alternatively, this software may be distributed under the terms of BSD 10*6d49e1aeSJan Lentfer * license. 11*6d49e1aeSJan Lentfer * 12*6d49e1aeSJan Lentfer * See README and COPYING for more details. 13*6d49e1aeSJan Lentfer */ 14*6d49e1aeSJan Lentfer 15*6d49e1aeSJan Lentfer #include "includes.h" 16*6d49e1aeSJan Lentfer 17*6d49e1aeSJan Lentfer #include "common.h" 18*6d49e1aeSJan Lentfer #include "ms_funcs.h" 19*6d49e1aeSJan Lentfer #include "mschapv2.h" 20*6d49e1aeSJan Lentfer 21*6d49e1aeSJan Lentfer const u8 * mschapv2_remove_domain(const u8 *username, size_t *len) 22*6d49e1aeSJan Lentfer { 23*6d49e1aeSJan Lentfer size_t i; 24*6d49e1aeSJan Lentfer 25*6d49e1aeSJan Lentfer /* 26*6d49e1aeSJan Lentfer * MSCHAPv2 does not include optional domain name in the 27*6d49e1aeSJan Lentfer * challenge-response calculation, so remove domain prefix 28*6d49e1aeSJan Lentfer * (if present). 29*6d49e1aeSJan Lentfer */ 30*6d49e1aeSJan Lentfer 31*6d49e1aeSJan Lentfer for (i = 0; i < *len; i++) { 32*6d49e1aeSJan Lentfer if (username[i] == '\\') { 33*6d49e1aeSJan Lentfer *len -= i + 1; 34*6d49e1aeSJan Lentfer return username + i + 1; 35*6d49e1aeSJan Lentfer } 36*6d49e1aeSJan Lentfer } 37*6d49e1aeSJan Lentfer 38*6d49e1aeSJan Lentfer return username; 39*6d49e1aeSJan Lentfer } 40*6d49e1aeSJan Lentfer 41*6d49e1aeSJan Lentfer 42*6d49e1aeSJan Lentfer void mschapv2_derive_response(const u8 *identity, size_t identity_len, 43*6d49e1aeSJan Lentfer const u8 *password, size_t password_len, 44*6d49e1aeSJan Lentfer int pwhash, 45*6d49e1aeSJan Lentfer const u8 *auth_challenge, 46*6d49e1aeSJan Lentfer const u8 *peer_challenge, 47*6d49e1aeSJan Lentfer u8 *nt_response, u8 *auth_response, 48*6d49e1aeSJan Lentfer u8 *master_key) 49*6d49e1aeSJan Lentfer { 50*6d49e1aeSJan Lentfer const u8 *username; 51*6d49e1aeSJan Lentfer size_t username_len; 52*6d49e1aeSJan Lentfer u8 password_hash[16], password_hash_hash[16]; 53*6d49e1aeSJan Lentfer 54*6d49e1aeSJan Lentfer wpa_hexdump_ascii(MSG_DEBUG, "MSCHAPV2: Identity", 55*6d49e1aeSJan Lentfer identity, identity_len); 56*6d49e1aeSJan Lentfer username_len = identity_len; 57*6d49e1aeSJan Lentfer username = mschapv2_remove_domain(identity, &username_len); 58*6d49e1aeSJan Lentfer wpa_hexdump_ascii(MSG_DEBUG, "MSCHAPV2: Username", 59*6d49e1aeSJan Lentfer username, username_len); 60*6d49e1aeSJan Lentfer 61*6d49e1aeSJan Lentfer wpa_hexdump(MSG_DEBUG, "MSCHAPV2: auth_challenge", 62*6d49e1aeSJan Lentfer auth_challenge, MSCHAPV2_CHAL_LEN); 63*6d49e1aeSJan Lentfer wpa_hexdump(MSG_DEBUG, "MSCHAPV2: peer_challenge", 64*6d49e1aeSJan Lentfer peer_challenge, MSCHAPV2_CHAL_LEN); 65*6d49e1aeSJan Lentfer wpa_hexdump_ascii(MSG_DEBUG, "MSCHAPV2: username", 66*6d49e1aeSJan Lentfer username, username_len); 67*6d49e1aeSJan Lentfer /* Authenticator response is not really needed yet, but calculate it 68*6d49e1aeSJan Lentfer * here so that challenges need not be saved. */ 69*6d49e1aeSJan Lentfer if (pwhash) { 70*6d49e1aeSJan Lentfer wpa_hexdump_key(MSG_DEBUG, "MSCHAPV2: password hash", 71*6d49e1aeSJan Lentfer password, password_len); 72*6d49e1aeSJan Lentfer generate_nt_response_pwhash(auth_challenge, peer_challenge, 73*6d49e1aeSJan Lentfer username, username_len, 74*6d49e1aeSJan Lentfer password, nt_response); 75*6d49e1aeSJan Lentfer generate_authenticator_response_pwhash( 76*6d49e1aeSJan Lentfer password, peer_challenge, auth_challenge, 77*6d49e1aeSJan Lentfer username, username_len, nt_response, auth_response); 78*6d49e1aeSJan Lentfer } else { 79*6d49e1aeSJan Lentfer wpa_hexdump_ascii_key(MSG_DEBUG, "MSCHAPV2: password", 80*6d49e1aeSJan Lentfer password, password_len); 81*6d49e1aeSJan Lentfer generate_nt_response(auth_challenge, peer_challenge, 82*6d49e1aeSJan Lentfer username, username_len, 83*6d49e1aeSJan Lentfer password, password_len, nt_response); 84*6d49e1aeSJan Lentfer generate_authenticator_response(password, password_len, 85*6d49e1aeSJan Lentfer peer_challenge, auth_challenge, 86*6d49e1aeSJan Lentfer username, username_len, 87*6d49e1aeSJan Lentfer nt_response, auth_response); 88*6d49e1aeSJan Lentfer } 89*6d49e1aeSJan Lentfer wpa_hexdump(MSG_DEBUG, "MSCHAPV2: NT Response", 90*6d49e1aeSJan Lentfer nt_response, MSCHAPV2_NT_RESPONSE_LEN); 91*6d49e1aeSJan Lentfer wpa_hexdump(MSG_DEBUG, "MSCHAPV2: Auth Response", 92*6d49e1aeSJan Lentfer auth_response, MSCHAPV2_AUTH_RESPONSE_LEN); 93*6d49e1aeSJan Lentfer 94*6d49e1aeSJan Lentfer /* Generate master_key here since we have the needed data available. */ 95*6d49e1aeSJan Lentfer if (pwhash) { 96*6d49e1aeSJan Lentfer hash_nt_password_hash(password, password_hash_hash); 97*6d49e1aeSJan Lentfer } else { 98*6d49e1aeSJan Lentfer nt_password_hash(password, password_len, password_hash); 99*6d49e1aeSJan Lentfer hash_nt_password_hash(password_hash, password_hash_hash); 100*6d49e1aeSJan Lentfer } 101*6d49e1aeSJan Lentfer get_master_key(password_hash_hash, nt_response, master_key); 102*6d49e1aeSJan Lentfer wpa_hexdump_key(MSG_DEBUG, "MSCHAPV2: Master Key", 103*6d49e1aeSJan Lentfer master_key, MSCHAPV2_MASTER_KEY_LEN); 104*6d49e1aeSJan Lentfer } 105*6d49e1aeSJan Lentfer 106*6d49e1aeSJan Lentfer 107*6d49e1aeSJan Lentfer int mschapv2_verify_auth_response(const u8 *auth_response, 108*6d49e1aeSJan Lentfer const u8 *buf, size_t buf_len) 109*6d49e1aeSJan Lentfer { 110*6d49e1aeSJan Lentfer u8 recv_response[MSCHAPV2_AUTH_RESPONSE_LEN]; 111*6d49e1aeSJan Lentfer if (buf_len < 2 + 2 * MSCHAPV2_AUTH_RESPONSE_LEN || 112*6d49e1aeSJan Lentfer buf[0] != 'S' || buf[1] != '=' || 113*6d49e1aeSJan Lentfer hexstr2bin((char *) (buf + 2), recv_response, 114*6d49e1aeSJan Lentfer MSCHAPV2_AUTH_RESPONSE_LEN) || 115*6d49e1aeSJan Lentfer os_memcmp(auth_response, recv_response, 116*6d49e1aeSJan Lentfer MSCHAPV2_AUTH_RESPONSE_LEN) != 0) 117*6d49e1aeSJan Lentfer return -1; 118*6d49e1aeSJan Lentfer return 0; 119*6d49e1aeSJan Lentfer } 120