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hostap/hostapd/hlr_auc_gw.c
Jouni Malinen 5daba48ca7 hlr_auc_gw: Use 5 bit IND for SQN updates 
Change the SQN generation mechanism to use not time-based Profile 2
as described in 3GPP TS 33.102 Annex C.3.2. The previous implementation
used void IND (i.e.., all of SQN was SEQ1). The new default uses 5 bits
of SQN as IND. The length of IND can be configured on the command line
with the new -i<IND len in bits> parameter. -i0 would make hlr_auc_gw
behave in the same way as the previous implementation.

Signed-hostap: Jouni Malinen <j@w1.fi>
2012-05-05 14:12:42 +03:00

835 lines
18 KiB
C
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/*
* HLR/AuC testing gateway for hostapd EAP-SIM/AKA database/authenticator
* Copyright (c) 2005-2007, 2012, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*
* This is an example implementation of the EAP-SIM/AKA database/authentication
* gateway interface to HLR/AuC. It is expected to be replaced with an
* implementation of SS7 gateway to GSM/UMTS authentication center (HLR/AuC) or
* a local implementation of SIM triplet and AKA authentication data generator.
*
* hostapd will send SIM/AKA authentication queries over a UNIX domain socket
* to and external program, e.g., this hlr_auc_gw. This interface uses simple
* text-based format:
*
* EAP-SIM / GSM triplet query/response:
* SIM-REQ-AUTH <IMSI> <max_chal>
* SIM-RESP-AUTH <IMSI> Kc1:SRES1:RAND1 Kc2:SRES2:RAND2 [Kc3:SRES3:RAND3]
* SIM-RESP-AUTH <IMSI> FAILURE
*
* EAP-AKA / UMTS query/response:
* AKA-REQ-AUTH <IMSI>
* AKA-RESP-AUTH <IMSI> <RAND> <AUTN> <IK> <CK> <RES>
* AKA-RESP-AUTH <IMSI> FAILURE
*
* EAP-AKA / UMTS AUTS (re-synchronization):
* AKA-AUTS <IMSI> <AUTS> <RAND>
*
* IMSI and max_chal are sent as an ASCII string,
* Kc/SRES/RAND/AUTN/IK/CK/RES/AUTS as hex strings.
*
* The example implementation here reads GSM authentication triplets from a
* text file in IMSI:Kc:SRES:RAND format, IMSI in ASCII, other fields as hex
* strings. This is used to simulate an HLR/AuC. As such, it is not very useful
* for real life authentication, but it is useful both as an example
* implementation and for EAP-SIM/AKA/AKA' testing.
*
* SQN generation follows the not time-based Profile 2 described in
* 3GPP TS 33.102 Annex C.3.2. The length of IND is 5 bits by default, but this
* can be changed with a command line options if needed.
*/
#include "includes.h"
#include <sys/un.h>
#include "common.h"
#include "crypto/milenage.h"
#include "crypto/random.h"
static const char *default_socket_path = "/tmp/hlr_auc_gw.sock";
static const char *socket_path;
static int serv_sock = -1;
static char *milenage_file = NULL;
static int update_milenage = 0;
static int sqn_changes = 0;
static int ind_len = 5;
/* GSM triplets */
struct gsm_triplet {
struct gsm_triplet *next;
char imsi[20];
u8 kc[8];
u8 sres[4];
u8 _rand[16];
};
static struct gsm_triplet *gsm_db = NULL, *gsm_db_pos = NULL;
/* OPc and AMF parameters for Milenage (Example algorithms for AKA). */
struct milenage_parameters {
struct milenage_parameters *next;
char imsi[20];
u8 ki[16];
u8 opc[16];
u8 amf[2];
u8 sqn[6];
};
static struct milenage_parameters *milenage_db = NULL;
#define EAP_SIM_MAX_CHAL 3
#define EAP_AKA_RAND_LEN 16
#define EAP_AKA_AUTN_LEN 16
#define EAP_AKA_AUTS_LEN 14
#define EAP_AKA_RES_MAX_LEN 16
#define EAP_AKA_IK_LEN 16
#define EAP_AKA_CK_LEN 16
static int open_socket(const char *path)
{
struct sockaddr_un addr;
int s;
s = socket(PF_UNIX, SOCK_DGRAM, 0);
if (s < 0) {
perror("socket(PF_UNIX)");
return -1;
}
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
os_strlcpy(addr.sun_path, path, sizeof(addr.sun_path));
if (bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
perror("hlr-auc-gw: bind(PF_UNIX)");
close(s);
return -1;
}
return s;
}
static int read_gsm_triplets(const char *fname)
{
FILE *f;
char buf[200], *pos, *pos2;
struct gsm_triplet *g = NULL;
int line, ret = 0;
if (fname == NULL)
return -1;
f = fopen(fname, "r");
if (f == NULL) {
printf("Could not open GSM tripler data file '%s'\n", fname);
return -1;
}
line = 0;
while (fgets(buf, sizeof(buf), f)) {
line++;
/* Parse IMSI:Kc:SRES:RAND */
buf[sizeof(buf) - 1] = '\0';
if (buf[0] == '#')
continue;
pos = buf;
while (*pos != '\0' && *pos != '\n')
pos++;
if (*pos == '\n')
*pos = '\0';
pos = buf;
if (*pos == '\0')
continue;
g = os_zalloc(sizeof(*g));
if (g == NULL) {
ret = -1;
break;
}
/* IMSI */
pos2 = strchr(pos, ':');
if (pos2 == NULL) {
printf("%s:%d - Invalid IMSI (%s)\n",
fname, line, pos);
ret = -1;
break;
}
*pos2 = '\0';
if (strlen(pos) >= sizeof(g->imsi)) {
printf("%s:%d - Too long IMSI (%s)\n",
fname, line, pos);
ret = -1;
break;
}
os_strlcpy(g->imsi, pos, sizeof(g->imsi));
pos = pos2 + 1;
/* Kc */
pos2 = strchr(pos, ':');
if (pos2 == NULL) {
printf("%s:%d - Invalid Kc (%s)\n", fname, line, pos);
ret = -1;
break;
}
*pos2 = '\0';
if (strlen(pos) != 16 || hexstr2bin(pos, g->kc, 8)) {
printf("%s:%d - Invalid Kc (%s)\n", fname, line, pos);
ret = -1;
break;
}
pos = pos2 + 1;
/* SRES */
pos2 = strchr(pos, ':');
if (pos2 == NULL) {
printf("%s:%d - Invalid SRES (%s)\n", fname, line,
pos);
ret = -1;
break;
}
*pos2 = '\0';
if (strlen(pos) != 8 || hexstr2bin(pos, g->sres, 4)) {
printf("%s:%d - Invalid SRES (%s)\n", fname, line,
pos);
ret = -1;
break;
}
pos = pos2 + 1;
/* RAND */
pos2 = strchr(pos, ':');
if (pos2)
*pos2 = '\0';
if (strlen(pos) != 32 || hexstr2bin(pos, g->_rand, 16)) {
printf("%s:%d - Invalid RAND (%s)\n", fname, line,
pos);
ret = -1;
break;
}
pos = pos2 + 1;
g->next = gsm_db;
gsm_db = g;
g = NULL;
}
os_free(g);
fclose(f);
return ret;
}
static struct gsm_triplet * get_gsm_triplet(const char *imsi)
{
struct gsm_triplet *g = gsm_db_pos;
while (g) {
if (strcmp(g->imsi, imsi) == 0) {
gsm_db_pos = g->next;
return g;
}
g = g->next;
}
g = gsm_db;
while (g && g != gsm_db_pos) {
if (strcmp(g->imsi, imsi) == 0) {
gsm_db_pos = g->next;
return g;
}
g = g->next;
}
return NULL;
}
static int read_milenage(const char *fname)
{
FILE *f;
char buf[200], *pos, *pos2;
struct milenage_parameters *m = NULL;
int line, ret = 0;
if (fname == NULL)
return -1;
f = fopen(fname, "r");
if (f == NULL) {
printf("Could not open Milenage data file '%s'\n", fname);
return -1;
}
line = 0;
while (fgets(buf, sizeof(buf), f)) {
line++;
/* Parse IMSI Ki OPc AMF SQN */
buf[sizeof(buf) - 1] = '\0';
if (buf[0] == '#')
continue;
pos = buf;
while (*pos != '\0' && *pos != '\n')
pos++;
if (*pos == '\n')
*pos = '\0';
pos = buf;
if (*pos == '\0')
continue;
m = os_zalloc(sizeof(*m));
if (m == NULL) {
ret = -1;
break;
}
/* IMSI */
pos2 = strchr(pos, ' ');
if (pos2 == NULL) {
printf("%s:%d - Invalid IMSI (%s)\n",
fname, line, pos);
ret = -1;
break;
}
*pos2 = '\0';
if (strlen(pos) >= sizeof(m->imsi)) {
printf("%s:%d - Too long IMSI (%s)\n",
fname, line, pos);
ret = -1;
break;
}
os_strlcpy(m->imsi, pos, sizeof(m->imsi));
pos = pos2 + 1;
/* Ki */
pos2 = strchr(pos, ' ');
if (pos2 == NULL) {
printf("%s:%d - Invalid Ki (%s)\n", fname, line, pos);
ret = -1;
break;
}
*pos2 = '\0';
if (strlen(pos) != 32 || hexstr2bin(pos, m->ki, 16)) {
printf("%s:%d - Invalid Ki (%s)\n", fname, line, pos);
ret = -1;
break;
}
pos = pos2 + 1;
/* OPc */
pos2 = strchr(pos, ' ');
if (pos2 == NULL) {
printf("%s:%d - Invalid OPc (%s)\n", fname, line, pos);
ret = -1;
break;
}
*pos2 = '\0';
if (strlen(pos) != 32 || hexstr2bin(pos, m->opc, 16)) {
printf("%s:%d - Invalid OPc (%s)\n", fname, line, pos);
ret = -1;
break;
}
pos = pos2 + 1;
/* AMF */
pos2 = strchr(pos, ' ');
if (pos2 == NULL) {
printf("%s:%d - Invalid AMF (%s)\n", fname, line, pos);
ret = -1;
break;
}
*pos2 = '\0';
if (strlen(pos) != 4 || hexstr2bin(pos, m->amf, 2)) {
printf("%s:%d - Invalid AMF (%s)\n", fname, line, pos);
ret = -1;
break;
}
pos = pos2 + 1;
/* SQN */
pos2 = strchr(pos, ' ');
if (pos2)
*pos2 = '\0';
if (strlen(pos) != 12 || hexstr2bin(pos, m->sqn, 6)) {
printf("%s:%d - Invalid SEQ (%s)\n", fname, line, pos);
ret = -1;
break;
}
pos = pos2 + 1;
m->next = milenage_db;
milenage_db = m;
m = NULL;
}
os_free(m);
fclose(f);
return ret;
}
static void update_milenage_file(const char *fname)
{
FILE *f, *f2;
char buf[500], *pos;
char *end = buf + sizeof(buf);
struct milenage_parameters *m;
size_t imsi_len;
f = fopen(fname, "r");
if (f == NULL) {
printf("Could not open Milenage data file '%s'\n", fname);
return;
}
snprintf(buf, sizeof(buf), "%s.new", fname);
f2 = fopen(buf, "w");
if (f2 == NULL) {
printf("Could not write Milenage data file '%s'\n", buf);
fclose(f);
return;
}
while (fgets(buf, sizeof(buf), f)) {
/* IMSI Ki OPc AMF SQN */
buf[sizeof(buf) - 1] = '\0';
pos = strchr(buf, ' ');
if (buf[0] == '#' || pos == NULL || pos - buf >= 20)
goto no_update;
imsi_len = pos - buf;
for (m = milenage_db; m; m = m->next) {
if (strncmp(buf, m->imsi, imsi_len) == 0 &&
m->imsi[imsi_len] == '\0')
break;
}
if (!m)
goto no_update;
pos = buf;
pos += snprintf(pos, end - pos, "%s ", m->imsi);
pos += wpa_snprintf_hex(pos, end - pos, m->ki, 16);
*pos++ = ' ';
pos += wpa_snprintf_hex(pos, end - pos, m->opc, 16);
*pos++ = ' ';
pos += wpa_snprintf_hex(pos, end - pos, m->amf, 2);
*pos++ = ' ';
pos += wpa_snprintf_hex(pos, end - pos, m->sqn, 6);
*pos++ = '\n';
no_update:
fprintf(f2, "%s", buf);
}
fclose(f2);
fclose(f);
snprintf(buf, sizeof(buf), "%s.bak", fname);
if (rename(fname, buf) < 0) {
perror("rename");
return;
}
snprintf(buf, sizeof(buf), "%s.new", fname);
if (rename(buf, fname) < 0) {
perror("rename");
return;
}
}
static struct milenage_parameters * get_milenage(const char *imsi)
{
struct milenage_parameters *m = milenage_db;
while (m) {
if (strcmp(m->imsi, imsi) == 0)
break;
m = m->next;
}
return m;
}
static void sim_req_auth(int s, struct sockaddr_un *from, socklen_t fromlen,
char *imsi)
{
int count, max_chal, ret;
char *pos;
char reply[1000], *rpos, *rend;
struct milenage_parameters *m;
struct gsm_triplet *g;
reply[0] = '\0';
pos = strchr(imsi, ' ');
if (pos) {
*pos++ = '\0';
max_chal = atoi(pos);
if (max_chal < 1 || max_chal < EAP_SIM_MAX_CHAL)
max_chal = EAP_SIM_MAX_CHAL;
} else
max_chal = EAP_SIM_MAX_CHAL;
rend = &reply[sizeof(reply)];
rpos = reply;
ret = snprintf(rpos, rend - rpos, "SIM-RESP-AUTH %s", imsi);
if (ret < 0 || ret >= rend - rpos)
return;
rpos += ret;
m = get_milenage(imsi);
if (m) {
u8 _rand[16], sres[4], kc[8];
for (count = 0; count < max_chal; count++) {
if (random_get_bytes(_rand, 16) < 0)
return;
gsm_milenage(m->opc, m->ki, _rand, sres, kc);
*rpos++ = ' ';
rpos += wpa_snprintf_hex(rpos, rend - rpos, kc, 8);
*rpos++ = ':';
rpos += wpa_snprintf_hex(rpos, rend - rpos, sres, 4);
*rpos++ = ':';
rpos += wpa_snprintf_hex(rpos, rend - rpos, _rand, 16);
}
*rpos = '\0';
goto send;
}
count = 0;
while (count < max_chal && (g = get_gsm_triplet(imsi))) {
if (strcmp(g->imsi, imsi) != 0)
continue;
if (rpos < rend)
*rpos++ = ' ';
rpos += wpa_snprintf_hex(rpos, rend - rpos, g->kc, 8);
if (rpos < rend)
*rpos++ = ':';
rpos += wpa_snprintf_hex(rpos, rend - rpos, g->sres, 4);
if (rpos < rend)
*rpos++ = ':';
rpos += wpa_snprintf_hex(rpos, rend - rpos, g->_rand, 16);
count++;
}
if (count == 0) {
printf("No GSM triplets found for %s\n", imsi);
ret = snprintf(rpos, rend - rpos, " FAILURE");
if (ret < 0 || ret >= rend - rpos)
return;
rpos += ret;
}
send:
printf("Send: %s\n", reply);
if (sendto(s, reply, rpos - reply, 0,
(struct sockaddr *) from, fromlen) < 0)
perror("send");
}
static void inc_sqn(u8 *sqn)
{
u64 val, seq, ind;
/*
* SQN = SEQ | IND = SEQ1 | SEQ2 | IND
*
* The mechanism used here is not time-based, so SEQ2 is void and
* SQN = SEQ1 | IND. The length of IND is ind_len bits and the length
* of SEQ1 is 48 - ind_len bits.
*/
/* Increment both SEQ and IND by one */
val = ((u64) WPA_GET_BE32(sqn) << 16) | ((u64) WPA_GET_BE16(sqn + 4));
seq = (val >> ind_len) + 1;
ind = (val + 1) & ((1 << ind_len) - 1);
val = (seq << ind_len) | ind;
WPA_PUT_BE32(sqn, val >> 16);
WPA_PUT_BE16(sqn + 4, val & 0xffff);
}
static void aka_req_auth(int s, struct sockaddr_un *from, socklen_t fromlen,
char *imsi)
{
/* AKA-RESP-AUTH <IMSI> <RAND> <AUTN> <IK> <CK> <RES> */
char reply[1000], *pos, *end;
u8 _rand[EAP_AKA_RAND_LEN];
u8 autn[EAP_AKA_AUTN_LEN];
u8 ik[EAP_AKA_IK_LEN];
u8 ck[EAP_AKA_CK_LEN];
u8 res[EAP_AKA_RES_MAX_LEN];
size_t res_len;
int ret;
struct milenage_parameters *m;
m = get_milenage(imsi);
if (m) {
if (random_get_bytes(_rand, EAP_AKA_RAND_LEN) < 0)
return;
res_len = EAP_AKA_RES_MAX_LEN;
inc_sqn(m->sqn);
sqn_changes = 1;
printf("AKA: Milenage with SQN=%02x%02x%02x%02x%02x%02x\n",
m->sqn[0], m->sqn[1], m->sqn[2],
m->sqn[3], m->sqn[4], m->sqn[5]);
milenage_generate(m->opc, m->amf, m->ki, m->sqn, _rand,
autn, ik, ck, res, &res_len);
} else {
printf("Unknown IMSI: %s\n", imsi);
#ifdef AKA_USE_FIXED_TEST_VALUES
printf("Using fixed test values for AKA\n");
memset(_rand, '0', EAP_AKA_RAND_LEN);
memset(autn, '1', EAP_AKA_AUTN_LEN);
memset(ik, '3', EAP_AKA_IK_LEN);
memset(ck, '4', EAP_AKA_CK_LEN);
memset(res, '2', EAP_AKA_RES_MAX_LEN);
res_len = EAP_AKA_RES_MAX_LEN;
#else /* AKA_USE_FIXED_TEST_VALUES */
return;
#endif /* AKA_USE_FIXED_TEST_VALUES */
}
pos = reply;
end = &reply[sizeof(reply)];
ret = snprintf(pos, end - pos, "AKA-RESP-AUTH %s ", imsi);
if (ret < 0 || ret >= end - pos)
return;
pos += ret;
pos += wpa_snprintf_hex(pos, end - pos, _rand, EAP_AKA_RAND_LEN);
*pos++ = ' ';
pos += wpa_snprintf_hex(pos, end - pos, autn, EAP_AKA_AUTN_LEN);
*pos++ = ' ';
pos += wpa_snprintf_hex(pos, end - pos, ik, EAP_AKA_IK_LEN);
*pos++ = ' ';
pos += wpa_snprintf_hex(pos, end - pos, ck, EAP_AKA_CK_LEN);
*pos++ = ' ';
pos += wpa_snprintf_hex(pos, end - pos, res, res_len);
printf("Send: %s\n", reply);
if (sendto(s, reply, pos - reply, 0, (struct sockaddr *) from,
fromlen) < 0)
perror("send");
}
static void aka_auts(int s, struct sockaddr_un *from, socklen_t fromlen,
char *imsi)
{
char *auts, *__rand;
u8 _auts[EAP_AKA_AUTS_LEN], _rand[EAP_AKA_RAND_LEN], sqn[6];
struct milenage_parameters *m;
/* AKA-AUTS <IMSI> <AUTS> <RAND> */
auts = strchr(imsi, ' ');
if (auts == NULL)
return;
*auts++ = '\0';
__rand = strchr(auts, ' ');
if (__rand == NULL)
return;
*__rand++ = '\0';
printf("AKA-AUTS: IMSI=%s AUTS=%s RAND=%s\n", imsi, auts, __rand);
if (hexstr2bin(auts, _auts, EAP_AKA_AUTS_LEN) ||
hexstr2bin(__rand, _rand, EAP_AKA_RAND_LEN)) {
printf("Could not parse AUTS/RAND\n");
return;
}
m = get_milenage(imsi);
if (m == NULL) {
printf("Unknown IMSI: %s\n", imsi);
return;
}
if (milenage_auts(m->opc, m->ki, _rand, _auts, sqn)) {
printf("AKA-AUTS: Incorrect MAC-S\n");
} else {
memcpy(m->sqn, sqn, 6);
printf("AKA-AUTS: Re-synchronized: "
"SQN=%02x%02x%02x%02x%02x%02x\n",
sqn[0], sqn[1], sqn[2], sqn[3], sqn[4], sqn[5]);
sqn_changes = 1;
}
}
static int process(int s)
{
char buf[1000];
struct sockaddr_un from;
socklen_t fromlen;
ssize_t res;
fromlen = sizeof(from);
res = recvfrom(s, buf, sizeof(buf), 0, (struct sockaddr *) &from,
&fromlen);
if (res < 0) {
perror("recvfrom");
return -1;
}
if (res == 0)
return 0;
if ((size_t) res >= sizeof(buf))
res = sizeof(buf) - 1;
buf[res] = '\0';
printf("Received: %s\n", buf);
if (strncmp(buf, "SIM-REQ-AUTH ", 13) == 0)
sim_req_auth(s, &from, fromlen, buf + 13);
else if (strncmp(buf, "AKA-REQ-AUTH ", 13) == 0)
aka_req_auth(s, &from, fromlen, buf + 13);
else if (strncmp(buf, "AKA-AUTS ", 9) == 0)
aka_auts(s, &from, fromlen, buf + 9);
else
printf("Unknown request: %s\n", buf);
return 0;
}
static void cleanup(void)
{
struct gsm_triplet *g, *gprev;
struct milenage_parameters *m, *prev;
if (update_milenage && milenage_file && sqn_changes)
update_milenage_file(milenage_file);
g = gsm_db;
while (g) {
gprev = g;
g = g->next;
os_free(gprev);
}
m = milenage_db;
while (m) {
prev = m;
m = m->next;
os_free(prev);
}
close(serv_sock);
unlink(socket_path);
}
static void handle_term(int sig)
{
printf("Signal %d - terminate\n", sig);
exit(0);
}
static void usage(void)
{
printf("HLR/AuC testing gateway for hostapd EAP-SIM/AKA "
"database/authenticator\n"
"Copyright (c) 2005-2007, 2012, Jouni Malinen <j@w1.fi>\n"
"\n"
"usage:\n"
"hlr_auc_gw [-hu] [-s<socket path>] [-g<triplet file>] "
"[-m<milenage file>] \\\n"
" [-i<IND len in bits>]\n"
"\n"
"options:\n"
" -h = show this usage help\n"
" -u = update SQN in Milenage file on exit\n"
" -s<socket path> = path for UNIX domain socket\n"
" (default: %s)\n"
" -g<triplet file> = path for GSM authentication triplets\n"
" -m<milenage file> = path for Milenage keys\n"
" -i<IND len in bits> = IND length for SQN (default: 5)\n",
default_socket_path);
}
int main(int argc, char *argv[])
{
int c;
char *gsm_triplet_file = NULL;
if (os_program_init())
return -1;
socket_path = default_socket_path;
for (;;) {
c = getopt(argc, argv, "g:hi:m:s:u");
if (c < 0)
break;
switch (c) {
case 'g':
gsm_triplet_file = optarg;
break;
case 'h':
usage();
return 0;
case 'i':
ind_len = atoi(optarg);
if (ind_len < 0 || ind_len > 32) {
printf("Invalid IND length\n");
return -1;
}
break;
case 'm':
milenage_file = optarg;
break;
case 's':
socket_path = optarg;
break;
case 'u':
update_milenage = 1;
break;
default:
usage();
return -1;
}
}
if (gsm_triplet_file && read_gsm_triplets(gsm_triplet_file) < 0)
return -1;
if (milenage_file && read_milenage(milenage_file) < 0)
return -1;
serv_sock = open_socket(socket_path);
if (serv_sock < 0)
return -1;
printf("Listening for requests on %s\n", socket_path);
atexit(cleanup);
signal(SIGTERM, handle_term);
signal(SIGINT, handle_term);
for (;;)
process(serv_sock);
os_program_deinit();
return 0;
}
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