/* * Copyright (c) 1995, 1996, 1997 Kungliga Tekniska Hgskolan * (Royal Institute of Technology, Stockholm, Sweden). * 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 the Kungliga Tekniska * Hgskolan and its contributors. * * 4. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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. */ #include "sasl_mac_krb_locl.h" RCSID("$Id: rd_safe.c,v 1.1 2004/03/31 18:08:40 dasenbro Exp $"); /* application include files */ #include "krb-archaeology.h" /* Generate two checksums in the given byteorder of the data, one * new-form and one old-form. It has to be done this way to be * compatible with the old version of des_quad_cksum. */ /* des_quad_chsum-type; 0 == unknown, 1 == new PL10++, 2 == old */ int dqc_type = DES_QUAD_DEFAULT; void fixup_quad_cksum(void *start, size_t len, des_cblock *key, void *new_checksum, void *old_checksum, int little) { des_quad_cksum((des_cblock*)start, (des_cblock*)new_checksum, len, 2, key); if(HOST_BYTE_ORDER){ if(little){ memcpy(old_checksum, new_checksum, 16); }else{ u_int32_t *tmp = (u_int32_t*)new_checksum; memcpy(old_checksum, new_checksum, 16); swap_u_16(old_checksum); swap_u_long(tmp[0]); swap_u_long(tmp[1]); swap_u_long(tmp[2]); swap_u_long(tmp[3]); } }else{ if(little){ u_int32_t *tmp = (u_int32_t*)new_checksum; swap_u_long(tmp[0]); swap_u_long(tmp[1]); swap_u_long(tmp[2]); swap_u_long(tmp[3]); memcpy(old_checksum, new_checksum, 16); }else{ u_int32_t tmp[4]; tmp[0] = ((u_int32_t*)new_checksum)[3]; tmp[1] = ((u_int32_t*)new_checksum)[2]; tmp[2] = ((u_int32_t*)new_checksum)[1]; tmp[3] = ((u_int32_t*)new_checksum)[0]; memcpy(old_checksum, tmp, 16); } } } /* * krb_rd_safe() checks the integrity of an AUTH_MSG_SAFE message. * Given the message received, "in", the length of that message, * "in_length", the "key" to compute the checksum with, and the * network addresses of the "sender" and "receiver" of the message, * krb_rd_safe() returns RD_AP_OK if message is okay, otherwise * some error code. * * The message data retrieved from "in" is returned in the structure * "m_data". The pointer to the application data (m_data->app_data) * refers back to the appropriate place in "in". * * See the file "mk_safe.c" for the format of the AUTH_MSG_SAFE * message. The structure containing the extracted message * information, MSG_DAT, is defined in "krb.h". */ int32_t krb_rd_safe(void *in, u_int32_t in_length, des_cblock *key, struct sockaddr_in *sender, struct sockaddr_in *receiver, MSG_DAT *m_data) { unsigned char *p = (unsigned char*)in, *start; unsigned char pvno, type; int little_endian; struct timeval tv; u_int32_t src_addr; int delta_t; pvno = *p++; if(pvno != KRB_PROT_VERSION) return RD_AP_VERSION; type = *p++; little_endian = type & 1; type &= ~1; if(type != AUTH_MSG_SAFE) return RD_AP_MSG_TYPE; start = p; p += krb_get_int(p, &m_data->app_length, 4, little_endian); if(m_data->app_length + 31 > in_length) return RD_AP_MODIFIED; m_data->app_data = p; p += m_data->app_length; m_data->time_5ms = *p++; p += krb_get_address(p, &src_addr); if (!krb_equiv(src_addr, sender->sin_addr.s_addr)) return RD_AP_BADD; p += krb_get_int(p, (u_int32_t *)&m_data->time_sec, 4, little_endian); m_data->time_sec = lsb_time(m_data->time_sec, sender, receiver); gettimeofday(&tv, NULL); delta_t = abs((int)((long) tv.tv_sec - m_data->time_sec)); if (delta_t > CLOCK_SKEW) return RD_AP_TIME; /* * caller must check timestamps for proper order and replays, since * server might have multiple clients each with its own timestamps * and we don't assume tightly synchronized clocks. */ { unsigned char new_checksum[16]; unsigned char old_checksum[16]; fixup_quad_cksum(start, p - start, key, new_checksum, old_checksum, little_endian); if((dqc_type == DES_QUAD_GUESS || dqc_type == DES_QUAD_NEW) && memcmp(new_checksum, p, 16) == 0) dqc_type = DES_QUAD_NEW; else if((dqc_type == DES_QUAD_GUESS || dqc_type == DES_QUAD_OLD) && memcmp(old_checksum, p, 16) == 0) dqc_type = DES_QUAD_OLD; else return RD_AP_MODIFIED; } return KSUCCESS; }