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siahsd/chirond.c

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/*
Chiron IP Alarm Monitoring Service
Copyright (C) Wilco Baan Hofman <wilco@baanhofman.nl> 2012
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 4 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "build/ndr_chiron.h"
#include "build/chiron.h"
#include <nettle/md5.h>
#include <nettle/arcfour.h>
#define CHIRON_PORT "53165"
// Function was licensed WTFPL, origin stack: overflow
// I am too lazy to write this myself, these days.
void hexdump (const char *desc, const void *addr, const int len) {
int i;
unsigned char buff[17];
unsigned char *pc = (unsigned char*)addr;
// Output description if given.
if (desc != NULL)
fprintf(stderr, "%s:\n", desc);
if (len == 0) {
fprintf(stderr, " ZERO LENGTH\n");
return;
}
if (len < 0) {
fprintf(stderr, " NEGATIVE LENGTH: %i\n",len);
return;
}
for (i = 0; i < len; i++) {
if ((i % 16) == 0) {
if (i != 0)
fprintf(stderr, " %s\n", buff);
fprintf(stderr, " %04x ", i);
}
fprintf(stderr, " %02x", pc[i]);
if ((pc[i] < 0x20) || (pc[i] > 0x7e))
buff[i % 16] = '.';
else
buff[i % 16] = pc[i];
buff[(i % 16) + 1] = '\0';
}
while ((i % 16) != 0) {
fprintf(stderr, " ");
i++;
}
fprintf(stderr, " %s\n", buff);
}
struct chiron_context {
int clientfd;
struct sockaddr *clientaddr;
char *account_code;
char device_id[3];
uint8_t md5_last_out[0x10];
uint8_t rc4key[0x10];
};
/* FIXME This function is a nasty little hack. */
char *ndr_print_chiron_msg_type_enum(TALLOC_CTX *mem_ctx, enum chiron_msg_type msg_type) {
char *ret;
struct ndr_print *ndr_print = talloc_zero(mem_ctx, struct ndr_print);
ndr_print->print = ndr_print_string_helper;
ndr_print->depth = 0;
ndr_print_chiron_msg_type(ndr_print, "", msg_type);
ret = talloc_steal(mem_ctx, ndr_print->private_data);
talloc_free(ndr_print);
return ret;
}
struct ll_tlv {
struct ll_tlv *next;
enum chiron_msg_type type;
uint8_t length;
void *data_ptr;
};
STATUS tlv_to_linked_list(TALLOC_CTX *mem_ctx, DATA_BLOB data, struct ll_tlv **first_element) {
uint8_t *tlvptr = data.data;
struct ll_tlv *prev_elem = NULL;
while (tlvptr + 2 < data.data + data.length) {
struct ll_tlv *element = talloc_zero(mem_ctx, struct ll_tlv);
if (prev_elem == NULL) {
*first_element = element;
} else {
prev_elem->next = element;
}
element->type = *tlvptr++;
element->length = *tlvptr++;
if (tlvptr + element->length > data.data + data.length) {
prev_elem->next = NULL;
talloc_free(element);
return ST_PARSE_ERROR;
}
element->data_ptr = tlvptr;
tlvptr += element->length;
prev_elem = element;
}
if (tlvptr < data.data + data.length) {
DEBUG(1, "Error: Left over bytes in TLV");
return ST_PARSE_ERROR;
}
return ST_OK;
}
STATUS handle_chiron_msg_ack(struct chiron_context *ctx, struct chiron_message *msg) {
DEBUG(3, "Received ACK");
return ST_OK;
}
STATUS send_chiron_msg_handshake(struct chiron_context *ctx, struct chiron_message *in) {
struct chiron_message *out = talloc_zero(in, struct chiron_message);
out->msg_type = CHIRON_HANDSHAKE;
out->seq = in->seq;
out->flags = 0xC0; /* FIXME: What does this do? */
const uint8_t payload[] = { 0x27, 0, 0x32, 0, 0x18, 0, 0x2D, 0 };
out->msg.handshake.data = talloc_memdup(out, payload, sizeof(payload));
out->msg.handshake.length = sizeof(payload);
struct arcfour_ctx rc4;
arcfour_set_key(&rc4, MD5_HASH_LEN, ctx->rc4key);
arcfour_crypt(&rc4, sizeof(payload), out->msg.handshake.data, payload);
hexdump("Crypted outgoing payload", out->msg.handshake.data, sizeof(payload));
DATA_BLOB raw_out;
enum ndr_err_code ndr_err = ndr_push_struct_blob(&raw_out, out, out, (ndr_push_flags_fn_t)ndr_push_chiron_message);
if (ndr_err != NDR_ERR_SUCCESS) {
DEBUG(0, "Error writing NDR data blob.");
return ST_WRITE_ERROR;
}
write(ctx->clientfd, raw_out.data, raw_out.length);
talloc_free(out);
return ST_OK;
}
STATUS handle_chiron_msg_response(struct chiron_context *ctx, struct chiron_message *msg) {
DATA_BLOB crypted, decrypted;
struct arcfour_ctx rc4;
struct ll_tlv *element;
if (memcmp(msg->msg.response.md5_check, ctx->md5_last_out, 0x10)) {
DEBUG(0, "MD5 does not match!\n");
return ST_PARSE_ERROR;
}
DEBUG(0, "Handling the response");
/* Copy packet to crypted data blob */
crypted.length = msg->msg.response.length - MD5_HASH_LEN;
crypted.data = talloc_memdup(msg, msg->msg.response.payload, crypted.length);
NO_MEM_RETURN(crypted.data);
decrypted.data = talloc_array(msg, uint8_t, crypted.length);
NO_MEM_RETURN(decrypted.data);
decrypted.length = crypted.length;
arcfour_set_key(&rc4, MD5_HASH_LEN, ctx->rc4key);
arcfour_crypt(&rc4, crypted.length, decrypted.data, crypted.data);
hexdump("Decrypted", decrypted.data, decrypted.length);
/* The message starts with 3 bytes device_id, and then the TLV starts */
memcpy(ctx->device_id, decrypted.data, 3);
decrypted.data += 3;
decrypted.length -= 3;
tlv_to_linked_list(msg, decrypted, &element);
while (element != NULL) {
DEBUG(1, "Type: %x, Length: %d", element->type, element->length);
hexdump("Data", element->data_ptr, element->length);
element = element->next;
}
send_chiron_msg_handshake(ctx, msg);
return ST_OK;
}
STATUS send_chiron_msg_challenge(struct chiron_context *ctx, struct chiron_message *in) {
struct chiron_message *out = talloc_zero(in, struct chiron_message);
struct md5_ctx md5;
uint8_t *md5input;
enum ndr_err_code ndr_err;
DATA_BLOB raw_out;
NO_MEM_RETURN(out);
DEBUG(0, "Sending out a challenge");
out->msg_type = CHIRON_CHALLENGE;
out->seq = in->seq;
out->flags = in->flags;
/* Make an md5 hash of the account code with the seq byte appended. */
md5input = talloc_array(in, uint8_t, in->msg.account.length + 1);
NO_MEM_RETURN(md5input);
memcpy(md5input, in->msg.account.account_code, in->msg.account.length);
md5input[in->msg.account.length] = in->seq;
out->msg.challenge.md5_check = talloc_array(out, uint8_t, MD5_HASH_LEN);
NO_MEM_RETURN(out->msg.challenge.md5_check);
md5_init(&md5);
md5_update(&md5, in->msg.account.length + 1, md5input);
md5_digest(&md5, MD5_HASH_LEN, out->msg.challenge.md5_check);
talloc_free(md5input);
/* FIXME This should be random, but that is annoying for testing purposes */
out->msg.challenge.length = MD5_HASH_LEN + CHALLENGE_LEN;
out->msg.challenge.challenge = talloc_zero_array(out, uint8_t, CHALLENGE_LEN);
NO_MEM_RETURN(out->msg.challenge.challenge);
#if 0
out->msg.challenge.challenge[0] = 0xd0;
out->msg.challenge.challenge[1] = 0x8b;
out->msg.challenge.challenge[2] = 0x29;
out->msg.challenge.challenge[3] = 0xd3;
out->msg.challenge.challenge[4] = 0x7c;
out->msg.challenge.challenge[5] = 0xfd;
out->msg.challenge.challenge[6] = 0xb5;
out->msg.challenge.challenge[7] = 0xc6;
out->msg.challenge.challenge[8] = 0x1e;
#endif
//0x04, 0x0d, 0x49, 0xc1, 0x3d, 0xc8, 0x1f, 0x5f, 0x47
#if 0
out->msg.challenge.challenge[0] = 0x04;
out->msg.challenge.challenge[1] = 0x0d;
out->msg.challenge.challenge[2] = 0x49;
out->msg.challenge.challenge[3] = 0xc1;
out->msg.challenge.challenge[4] = 0x3d;
out->msg.challenge.challenge[5] = 0xc8;
out->msg.challenge.challenge[6] = 0x1f;
out->msg.challenge.challenge[7] = 0x5f;
out->msg.challenge.challenge[8] = 0x47;
#endif
// 0x96, 0xf4, 0xc4, 0x86,
// 0xd9, 0x83, 0x4d, 0x87, 0x48
out->msg.challenge.challenge[0] = 0x96;
out->msg.challenge.challenge[1] = 0xf4;
out->msg.challenge.challenge[2] = 0xc4;
out->msg.challenge.challenge[3] = 0x86;
out->msg.challenge.challenge[4] = 0xd9;
out->msg.challenge.challenge[5] = 0x83;
out->msg.challenge.challenge[6] = 0x4d;
out->msg.challenge.challenge[7] = 0x87;
out->msg.challenge.challenge[8] = 0x48;
ndr_err = ndr_push_struct_blob(&raw_out, out, out, (ndr_push_flags_fn_t)ndr_push_chiron_message);
if (ndr_err != NDR_ERR_SUCCESS) {
DEBUG(0, "Error writing NDR data blob.");
return ST_WRITE_ERROR;
}
/* Update the md5 check for the next message (last 9 bytes with the seq byte appended). */
md5input = talloc_array(in, uint8_t, CHALLENGE_LEN + 1);
NO_MEM_RETURN(md5input);
memcpy(md5input, &raw_out.data[MSG_HDR_LEN + MD5_HASH_LEN], CHALLENGE_LEN);
md5input[CHALLENGE_LEN] = in->seq;
md5_init(&md5);
md5_update(&md5, CHALLENGE_LEN + 1, md5input);
md5_digest(&md5, MD5_HASH_LEN, ctx->md5_last_out);
/* Update the rc4 crypto key, which is seq+challenge */
md5input[0] = in->seq;
memcpy(&md5input[1], &raw_out.data[MSG_HDR_LEN + MD5_HASH_LEN], CHALLENGE_LEN);
md5_init(&md5);
md5_update(&md5, CHALLENGE_LEN + 1, md5input);
md5_digest(&md5, MD5_HASH_LEN, ctx->rc4key);
DEBUG(0, "The expected md5sum for the next entry is %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
ctx->md5_last_out[0], ctx->md5_last_out[1], ctx->md5_last_out[2], ctx->md5_last_out[3],
ctx->md5_last_out[4], ctx->md5_last_out[5], ctx->md5_last_out[6], ctx->md5_last_out[9],
ctx->md5_last_out[8], ctx->md5_last_out[9], ctx->md5_last_out[10], ctx->md5_last_out[11],
ctx->md5_last_out[12], ctx->md5_last_out[13], ctx->md5_last_out[14], ctx->md5_last_out[15]);
write(ctx->clientfd, raw_out.data, raw_out.length);
talloc_free(out);
return ST_OK;
}
STATUS handle_chiron_msg_account(struct chiron_context *ctx, struct chiron_message *msg) {
ctx->account_code = talloc_memdup(msg, msg->msg.account.account_code, msg->msg.account.length);
NO_MEM_RETURN(ctx->account_code);
send_chiron_msg_challenge(ctx, msg);
return ST_OK;
}
STATUS handle_message(struct chiron_context *ctx, DATA_BLOB data) {
struct chiron_message *msg;
enum ndr_err_code ndr_err;
STATUS status;
msg = talloc(data.data, struct chiron_message);
NO_MEM_RETURN(msg);
/* Parse the packet */
ndr_err = ndr_pull_struct_blob_all(&data, msg, msg, (ndr_pull_flags_fn_t)ndr_pull_chiron_message);
if (ndr_err != NDR_ERR_SUCCESS) {
DEBUG(0, "Could not parse this message");
return ST_PARSE_ERROR;
}
DEBUG(0, "%s", ndr_print_struct_string(msg,(ndr_print_fn_t)ndr_print_chiron_message, "chiron message", msg));
switch (msg->msg_type) {
case CHIRON_ACCOUNT:
status = handle_chiron_msg_account(ctx, msg);
break;
case CHIRON_RESPONSE:
status = handle_chiron_msg_response(ctx, msg);
break;
case CHIRON_ACK:
status = handle_chiron_msg_ack(ctx, msg);
default:
DEBUG(0, "Got unexpected message type: %s.",
ndr_print_chiron_msg_type_enum(msg, msg->msg_type));
break;
}
if (status != ST_OK) {
return status;
}
talloc_free(msg);
return ST_OK;
}
STATUS handle_connection(struct chiron_context *ctx) {
int n;
char buf[1024]; /* Purposefully static length */
DATA_BLOB data;
while ((n = read(ctx->clientfd, buf, sizeof(buf)))) {
if (n < 0) {
DEBUG( 0, "Error when storing packet in buffer!");
return ST_PARSE_ERROR;
} else if (n == sizeof(buf)) {
DEBUG(0, "Maximum packet size exceeded!");
return ST_PARSE_ERROR;
}
/* Copy packet to data blob */
data.length = n;
data.data = talloc_memdup(ctx, buf, n);
NO_MEM_RETURN(data.data);
talloc_free(data.data);
}
return ST_OK;
}
static STATUS daemonize(char *pid_file) {
FILE *pidfile;
pid_t pid;
fclose(stdin);
fclose(stdout);
fclose(stderr);
if ((pid = fork())) {
/* Write PID file */
pidfile = fopen(pid_file, "w");
if (pidfile == NULL)
exit(1);
fprintf(pidfile, "%d\n", pid);
fclose(pidfile);
exit(0);
}
return ST_OK;
}
static STATUS listen_server(TALLOC_CTX *mem_ctx, const char *bindaddr, const char *bindport, const char *protocol, STATUS (*dispatcher)(struct chiron_context *)) {
int sock;
socklen_t clientlen;
struct addrinfo hints, *server, *first_server;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_flags = AI_PASSIVE;
getaddrinfo(bindaddr, bindport, &hints, &server);
first_server = server;
while (server) {
sock = socket(server->ai_family, SOCK_STREAM, 0);
if (sock >= 0) {
int optval = 1;
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval));
if (bind(sock, server->ai_addr, server->ai_addrlen) < 0) {
close(sock);
sock = -1;
} else {
break;
}
}
server = server->ai_next;
}
if (sock < 0) {
DEBUG(0, "Could not create socket in server");
return ST_SOCKET_FAILURE;
}
listen(sock, 128);
freeaddrinfo(first_server);
DEBUG(0, "Started %s and waiting for Chiron messages on port %s",
get_process_name(), CHIRON_PORT);
/*
* Wait for connections
*/
clientlen = sizeof(struct addrinfo);
while (1) {
int clientfd;
struct sockaddr_storage clientaddr;
char clienthost[NI_MAXHOST];
char clientservice[NI_MAXSERV];
clientfd = accept(sock, (struct sockaddr *)&clientaddr, &clientlen);
getnameinfo((struct sockaddr *)&clientaddr, clientlen,
clienthost, sizeof(clienthost),
clientservice, sizeof(clientservice),
NI_NUMERICHOST | NI_NUMERICSERV);
DEBUG(3, "Received connection from %s:%s", clienthost, clientservice);
//if (fork()) {
// continue;
//} else {
{
struct chiron_context *client_ctx = talloc_zero(mem_ctx, struct chiron_context);
NO_MEM_RETURN(client_ctx);
client_ctx->clientaddr = (struct sockaddr *)&clientaddr;
client_ctx->clientfd = clientfd;
dispatcher(client_ctx);
shutdown(client_ctx->clientfd, SHUT_RDWR);
close(client_ctx->clientfd);
talloc_free(client_ctx);
exit(0);
}
}
shutdown(sock, SHUT_RDWR);
close(sock);
}
int main (int argc, char **argv) {
TALLOC_CTX *mem_ctx;
STATUS rv;
const configuration *conf;
set_process_name(argv[0]);
/* Initialize a memory context */
mem_ctx = talloc_init("chirond");
/* Read the configuration file */
rv = read_configuration_file(mem_ctx);
if (rv != ST_OK)
return rv;
conf = get_conf();
/* Daemonize if we're not supposed to run in foreground mode */
if (!conf->foreground) {
daemonize(conf->pid_file);
}
struct chiron_context *client_ctx = talloc_zero(mem_ctx, struct chiron_context);
NO_MEM_RETURN(client_ctx);
client_ctx->clientfd = 1;
client_ctx->clientaddr = (struct sockaddr *)talloc_zero(mem_ctx, struct sockaddr_storage);
#if 0
// Account
const uint8_t in_message1[] = { 0x41, 0x01, 0xa8, 0x04, 0x33, 0x35, 0x30, 0x30 };
// Challenge
const uint8_t out_message1[] = { 0x43, 0x01, 0xa8, 0x19, 0x28, 0xd5, 0xdc, 0x57,
0x44, 0x77, 0x0d, 0xea, 0xc0, 0x03, 0x56, 0xca,
0x42, 0x72, 0x18, 0x30, 0xd0, 0x8b, 0x29, 0xd3,
0x7c, 0xfd, 0xb5, 0xc6, 0x1e };
// Response
const uint8_t in_message2[] = { 0x52, 0x01, 0xa8, 0x37, 0x62, 0x7f, 0xd0, 0xb8, 0xbc, 0x70, 0x6a, 0x44, 0x44, 0x21, 0x15, 0xb4, 0x94, 0x20, 0x62, 0x98, 0x7a, 0xe2, 0xde, 0xc2, 0xed, 0x76, 0x84, 0x5f, 0xe6, 0x16, 0x2b, 0x6b, 0xb9, 0x10, 0xa3, 0x6c, 0x14, 0x44, 0x56, 0xca, 0x45, 0xc6, 0xc2, 0xeb, 0xec, 0x1b, 0xd8, 0x7a, 0xa4, 0x4c, 0xc0, 0xb4, 0x88, 0x64, 0x6e, 0x2b, 0xee, 0x11, 0x54 };
// Handshake
const uint8_t out_message2[] = { 0x4b, 0x01, 0xc0, 0x08, 0x5d, 0x4f, 0x2b, 0xce, 0xf1, 0xde, 0x77, 0xa1 };
// Ack
const uint8_t in_message3[] = { 0x55, 0x01, 0xa8, 0x00 };
#endif
#if 0
const uint8_t in_message1[] = { 0x41, 0x02, 0xa8, 0x04, 0x33, 0x35, 0x30, 0x30 };
const uint8_t out_message1[] = { 0x43, 0x02, 0xa8, 0x19, 0x08, 0x71, 0x4f, 0xad, 0xed, 0xa3, 0xaf, 0x37, 0x88, 0xcc, 0x00, 0x51, 0xe4, 0xcb, 0xad, 0x7c, 0x04, 0x0d, 0x49, 0xc1, 0x3d, 0xc8, 0x1f, 0x5f, 0x47 };
const uint8_t in_message2[] = { 0x52, 0x02, 0xa8, 0x46, 0xc8, 0xa8, 0xb6, 0x50, 0x34, 0xd5, 0x7a, 0x26, 0x90, 0x63, 0x92, 0x56, 0xe5, 0x4d, 0xde, 0xa0, 0x6a, 0x60, 0x19, 0xdc, 0x67, 0xbb, 0xe8, 0x9e, 0x8e, 0xfc, 0x79, 0x55, 0xed, 0x66, 0x26, 0x21, 0x1a, 0x6b, 0x4a, 0x9c, 0x7c, 0xe6, 0x1d, 0x01, 0xab, 0x57, 0xfb, 0xd9, 0x6d, 0x15, 0xbd, 0xe6, 0xe3, 0x94, 0xd6, 0xe7, 0xde, 0xc3, 0x89, 0x52, 0x65, 0x5f, 0x0c, 0x97, 0x4e, 0x4f, 0x6d, 0x9f, 0x5a, 0xb9, 0xc2, 0x12, 0xdd, 0x74 };
const uint8_t out_message2[] = { 0x4b, 0x02, 0xc0, 0x00 };
#endif
const uint8_t in_message1[] = {
0x41, 0x03, 0x88, 0x04, 0x33, 0x35, 0x30, 0x30 };
const uint8_t out_message1[] = {
0x43, 0x03, 0x88, 0x19, 0xaa, 0xd9, 0xaa, 0x5f,
0x30, 0x5d, 0x95, 0x0d, 0x96, 0x8d, 0x4e, 0x26,
0x02, 0x1a, 0x1a, 0xd8, 0x96, 0xf4, 0xc4, 0x86,
0xd9, 0x83, 0x4d, 0x87, 0x48 };
const uint8_t in_message2[] = {
0x52, 0x03, 0x88, 0x1f, 0xe5, 0x65, 0x48, 0x30,
0x56, 0x8e, 0x3b, 0x42, 0x02, 0x6c, 0xcc, 0x9b,
0xdc, 0x82, 0xb0, 0x17, 0xba, 0xef, 0x52, 0x61,
0xe8, 0xce, 0x7b, 0xcb, 0x57, 0x85, 0x2b, 0x18,
0xbf, 0xfa, 0xf1 };
const uint8_t out_message2[] = {
0x4b, 0x03, 0xc0, 0x00 };
DATA_BLOB data;
data.data = talloc_memdup(client_ctx, in_message1, sizeof(in_message1));
data.length = sizeof(in_message1);
handle_message(client_ctx, data);
talloc_free(data.data);
data.data = talloc_memdup(client_ctx, in_message2, sizeof(in_message2));
data.length = sizeof(in_message2);
handle_message(client_ctx, data);
talloc_free(data.data);
struct arcfour_ctx rc4;
arcfour_set_key(&rc4, MD5_HASH_LEN, client_ctx->rc4key);
uint8_t buf[sizeof(out_message2)] = {0};
arcfour_crypt(&rc4, sizeof(out_message2) - 4, buf, out_message2 + 4);
hexdump("Decrypted outgoing payload", buf, sizeof(out_message2) - 4);
return 0;
/*
* Open up a TCP socket the Chiron port
*/
listen_server(mem_ctx, "::", CHIRON_PORT, "tcp", handle_connection);
return 0;
}
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