/* * Copyright 1997,1998 Niels Provos * 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 Niels Provos. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. */ /* * handle_identity_request: * receive a IDENTITY_REQUEST packet; return -1 on failure, 0 on success */ #ifndef lint static char rcsid[] = "$Id: handle_identity_request.c,v 1.1 1998/11/14 23:37:23 deraadt Exp $"; #endif #include #include #include #include "config.h" #include "photuris.h" #include "packets.h" #include "state.h" #include "cookie.h" #include "buffer.h" #include "packet.h" #include "encrypt.h" #include "identity.h" #include "spi.h" #include "secrets.h" #include "scheme.h" #include "errlog.h" #include "schedule.h" #include "attributes.h" #include "md5.h" #ifdef IPSEC #include "kernel.h" #endif #ifdef DEBUG #include "packet.h" #endif int handle_identity_request(u_char *packet, int size, char *address, char *local_address) { struct packet_sub parts[] = { { "IDChoice", FLD_ATTRIB, FMD_ATT_ONE, 0, }, { "Identity", FLD_VARPRE, 0, 0, }, { "Verification", FLD_VARPRE, 0, 0, }, { "Attributes", FLD_ATTRIB, FMD_ATT_FILL, 0, }, { NULL } }; struct packet id_msg = { "Identity Request", IDENTITY_MESSAGE_MIN, 0, parts }; struct identity_message *header; struct stateob *st; struct spiob *spi; MD5_CTX ctx; u_int8_t *p, *attributes; u_int16_t i, attribsize, tmp; u_int8_t signature[22]; /* XXX - constant */ if (size < IDENTITY_MESSAGE_MIN) return -1; /* packet too small */ header = (struct identity_message *) packet; st = state_find_cookies(address, header->icookie, header->rcookie); if (st == NULL) { packet_size = PACKET_BUFFER_SIZE; photuris_error_message(st, packet_buffer, &packet_size, header->icookie, header->rcookie, 0, BAD_COOKIE); send_packet(); return 0; } if (st->phase != VALUE_RESPONSE && st->phase != SPI_UPDATE) return -1; /* We don't want this packet */ /* Decrypt message */ tmp = size - IDENTITY_MESSAGE_MIN; if (packet_decrypt(st, IDENTITY_MESSAGE_CHOICE(header), &tmp) == -1) { log_error(0, "packet_decrypt() in handle_identity_request()"); goto verification_failed; } #ifdef DEBUG2 printf("Identity-Request (after decryption):\n"); packet_dump(packet, size, 0); #endif /* Verify message structure */ if (packet_check((u_int8_t *)header, size - packet[size-1], &id_msg) == -1) { log_error(0, "bad packet structure in handle_identity_request()"); return -1; } #ifdef DEBUG packet_ordered_dump(packet, size - packet[size-1], &id_msg); #endif /* Create a signature of this packet */ MD5Init(&ctx); MD5Update(&ctx, packet, size); MD5Final(signature, &ctx); if (st->phase != VALUE_RESPONSE) { /* * Compare with the identity request which got verified * initially. If matching resend our response. */ if (bcmp(signature, st->packetsig, sizeof(st->packetsig))) goto verification_failed; /* We got send the old packet again */ bcopy(st->packet, packet_buffer, st->packetlen); packet_size = st->packetlen; send_packet(); return 0; } else bcopy(signature, st->packetsig, sizeof(st->packetsig)); attributes = parts[3].where; attribsize = parts[3].size; if (!isattribsubset(st->oSPIoattrib,st->oSPIoattribsize, attributes, attribsize)) { log_error(0, "attributes are not a subset in handle_identity_request()"); return 0; } i = get_identity_verification_size(st, IDENTITY_MESSAGE_CHOICE(header)); if (!i || i != parts[2].size || i > sizeof(signature)) { log_error(0, "verification size mismatch in handle_identity_request()"); goto verification_failed; } bcopy(parts[2].where, signature, i); /* Fill the state object, but only if we have not dont so before */ if (st->uSPIidentver == NULL) { if((st->uSPIidentver = calloc(i, sizeof(u_int8_t))) == NULL) { log_error(1, "calloc() in handle_identity_request()"); goto verification_failed; } bcopy(signature, st->uSPIidentver, i); st->uSPIidentversize = i; } p = IDENTITY_MESSAGE_CHOICE(header); if (st->uSPIidentchoice == NULL) { if((st->uSPIidentchoice = calloc(p[1]+2, sizeof(u_int8_t))) == NULL) { log_error(1, "calloc() in handle_identity_request()"); goto verification_failed; } bcopy(p, st->uSPIidentchoice, p[1]+2); st->uSPIidentchoicesize = p[1]+2; } p += p[1] + 2; if (st->uSPIident == NULL) { if((st->uSPIident = calloc(varpre2octets(p), sizeof(u_int8_t))) == NULL) { log_error(1,"calloc() in handle_identity_request()"); goto verification_failed; } bcopy(p, st->uSPIident, varpre2octets(p)); } if (st->uSPIattrib == NULL) { if((st->uSPIattrib = calloc(attribsize, sizeof(u_int8_t))) == NULL) { log_error(1, "calloc() in handle_identity_request()"); return -1; } bcopy(attributes, st->uSPIattrib, attribsize); st->uSPIattribsize = attribsize; } if (st->oSPIident == NULL && get_secrets(st, (ID_REMOTE|ID_LOCAL)) == -1) { log_error(0, "get_secrets() in in handle_identity_request()"); goto verification_failed; } if (!verify_identity_verification(st, signature, packet, size)) { /* * Clean up everything used from this packet * but only if we did not get a valid packet before. * Otherwise this could be used as Denial of Service. */ free(st->uSPIidentchoice); st->uSPIidentchoice = NULL; st->uSPIidentchoicesize = 0; free(st->uSPIidentver); st->uSPIidentver = NULL; st->uSPIidentversize = 0; free(st->uSPIattrib); st->uSPIattrib = NULL; st->uSPIattribsize = 0; free(st->uSPIident); st->uSPIident = NULL; free(st->oSPIident); st->oSPIident = NULL; /* Clean up secrets */ free(st->oSPIsecret); st->oSPIsecret = NULL; st->oSPIsecretsize = 0; free(st->uSPIsecret); st->uSPIsecret = NULL; st->uSPIsecretsize = 0; verification_failed: log_error(0, "verification failed in handle_identity_request()"); packet_size = PACKET_BUFFER_SIZE; photuris_error_message(st, packet_buffer, &packet_size, header->icookie, header->rcookie, 0, VERIFICATION_FAILURE); send_packet(); return 0; } /* Create SPI + choice of attributes */ if(make_spi(st, local_address, st->oSPI, &(st->olifetime), &(st->oSPIattrib), &(st->oSPIattribsize)) == -1) { log_error(0, "make_spi() in handle_identity_request()"); return -1; } packet_size = PACKET_BUFFER_SIZE; if (photuris_identity_response(st, packet_buffer, &packet_size) == -1) return -1; send_packet(); packet_save(st, packet_buffer, packet_size); /* At this point we do not need the exchange values any longer */ free(st->texchange); st->texchange = NULL; free(st->exchangevalue); st->exchangevalue = NULL; bcopy(header->SPI, st->uSPI, SPI_SIZE); st->ulifetime = (header->lifetime[0] << 16) + (header->lifetime[1] << 8) + header->lifetime[2]; if (st->oSPI[0] || st->oSPI[1] || st->oSPI[2] || st->oSPI[3]) { /* Insert Owner SPI */ if ((spi = spi_new(st->address, st->oSPI)) == NULL) { log_error(0, "spi_new() in handle_identity_request()"); return -1; } if ((spi->local_address = strdup(local_address)) == NULL) { log_error(0, "strdup() in handle_identity_request()"); return -1; } bcopy(st->icookie, spi->icookie, COOKIE_SIZE); spi->flags |= SPI_OWNER; spi->attribsize = st->oSPIattribsize; spi->attributes = calloc(spi->attribsize, sizeof(u_int8_t)); if (spi->attributes == NULL) { log_error(1, "calloc() in handle_identity_request()"); spi_value_reset(spi); return -1; } bcopy(st->oSPIattrib, spi->attributes, spi->attribsize); spi->lifetime = time(NULL) + st->olifetime; /* Cludge for getting the right verification field */ state_save_verification(st, st->oSPIidentver, st->oSPIidentversize); /* Make session keys for Owner */ make_session_keys(st, spi); spi_insert(spi); #ifdef IPSEC kernel_insert_spi(st, spi); #endif schedule_insert(UPDATE, st->olifetime/2, spi->SPI, SPI_SIZE); } if (st->uSPI[0] || st->uSPI[1] || st->uSPI[2] || st->uSPI[3]) { /* Insert User SPI */ if ((spi = spi_new(st->address, st->uSPI)) == NULL) { log_error(0, "spi_new() in handle_identity_request()"); return -1; } if ((spi->local_address = strdup(local_address)) == NULL) { log_error(1, "strdup() in handle_identity_request()"); return -1; } spi->flags |= st->flags & IPSEC_NOTIFY ? SPI_NOTIFY : 0; bcopy(st->icookie, spi->icookie, COOKIE_SIZE); spi->attribsize = st->uSPIattribsize; spi->attributes = calloc(spi->attribsize, sizeof(u_int8_t)); if (spi->attributes == NULL) { log_error(1, "calloc() in handle_identity_request()"); spi_value_reset(spi); return -1; } bcopy(st->uSPIattrib, spi->attributes, spi->attribsize); spi->lifetime = time(NULL) + st->ulifetime; /* Cludge for getting the right verification field */ state_save_verification(st, st->uSPIidentver, st->uSPIidentversize); /* Make session keys for User */ make_session_keys(st, spi); spi_set_tunnel(st, spi); spi_insert(spi); #ifdef IPSEC kernel_insert_spi(st, spi); #endif } st->lifetime = st->exchange_lifetime + time(NULL) + random() % 20; st->retries = 0; st->phase = SPI_UPDATE; return 0; }