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mirror of https://git.kernel.org/pub/scm/network/wireless/iwd.git synced 2024-12-23 06:02:37 +01:00
iwd/plugins/sim_hardcoded.c
2018-06-14 19:58:04 -05:00

395 lines
8.8 KiB
C

/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2017 Intel Corporation. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <errno.h>
#include <ell/ell.h>
#include <ell/plugin.h>
#include "src/simauth.h"
struct hardcoded_sim {
char *identity;
uint8_t sim_supported;
uint8_t kc[NUM_RANDS_MAX][EAP_SIM_KC_LEN];
uint8_t sres[NUM_RANDS_MAX][EAP_SIM_SRES_LEN];
uint8_t aka_supported;
uint8_t ki[EAP_AKA_KI_LEN];
uint8_t opc[EAP_AKA_OPC_LEN];
uint8_t amf[EAP_AKA_AMF_LEN];
uint8_t sqn[EAP_AKA_SQN_LEN];
struct iwd_sim_auth *auth;
};
static struct hardcoded_sim *sim;
/*
* Helper to XOR an array
* to - result of XOR array
* a - array 1
* b - array 2
* len - size of aray
*/
#define XOR(to, a, b, len) \
for (i = 0; i < len; i++) { \
to[i] = a[i] ^ b[i]; \
}
static int get_milenage(const uint8_t *opc, const uint8_t *k,
const uint8_t *rand, const uint8_t *sqn, const uint8_t *amf,
const uint8_t *autn_in, uint8_t *autn, uint8_t *ck, uint8_t *ik,
uint8_t *res, uint8_t *auts)
{
/* algorithm variables: TEMP, IN1, OUT1, OUT2, OUT5 (OUT3/4 == IK/CK) */
uint8_t temp[16];
uint8_t in1[16];
uint8_t out1[16], out2[16], out5[16];
/* other variables */
struct l_cipher *aes;
int i;
uint8_t tmp1[16];
uint8_t tmp2[16];
uint8_t sqn_autn[6];
aes = l_cipher_new(L_CIPHER_AES, k, 16);
/* temp = TEMP = E[RAND ^ OPc]k */
XOR(tmp1, rand, opc, 16);
l_cipher_encrypt(aes, tmp1, temp, 16);
/* IN1[0-47] = SQN[0-47] */
memcpy(in1, sqn, 6);
/* IN1[48-63] = AMF[0-15] */
memcpy(in1 + 6, amf, 2);
/* IN1[64-111] = SQN[0-47] */
memcpy(in1 + 8, sqn, 6);
/* IN1[112-127] = AMF[0-15] */
memcpy(in1 + 14, amf, 2);
/*
* f1 and f1* output OUT1
*/
/*
* tmp1 = rot(IN1 ^ OPc)r1
* r1 = 64 bits = 8 bytes
*/
for (i = 0; i < 16; i++)
tmp1[(i + 8) % 16] = in1[i] ^ opc[i];
/* tmp2 = TEMP ^ tmp1 */
XOR(tmp2, temp, tmp1, 16);
/* tmp2 = E[tmp2]k */
l_cipher_encrypt(aes, tmp2, tmp1, 16);
/* out1 = OUT1 = tmp1 ^ opc */
XOR(out1, tmp1, opc, 16);
/*
* f2 outputs OUT2 (RES | AK)
*
* r2 = 0 == no rotation
*/
/* tmp1 = rot(TEMP ^ OPc)r2 */
XOR(tmp1, temp, opc, 16);
/* tmp1 ^ c2. c2 at bit 127 == 1 */
tmp1[15] ^= 1;
l_cipher_encrypt(aes, tmp1, out2, 16);
/* get RES from OUT2 */
XOR(out2, out2, opc, 16);
memcpy(res, out2 + 8, 8);
/* check input autn (AUTN ^ AK = SQN)*/
XOR(sqn_autn, autn_in, out2, 6);
/* if SQN was not correct, generate AUTS */
if (memcmp(sqn_autn, sqn, 6)) {
/*
* f5* outputs AK' (OUT5)
*/
for (i = 0; i < 16; i++)
tmp1[(i + 4) % 16] = temp[i] ^ opc[i];
/* tmp1 ^ c5. c5 at bit 124 == 1 */
tmp1[15] ^= 1 << 3;
l_cipher_encrypt(aes, tmp1, out5, 16);
/* out5 ^ opc */
XOR(out5, out5, opc, 16);
XOR(auts, sqn, out5, 6);
/* run f1 with zero'd AMF to finish AUTS */
in1[6] = 0x00;
in1[7] = 0x00;
in1[14] = 0x00;
in1[15] = 0x00;
for (i = 0; i < 16; i++)
tmp1[(i + 8) % 16] = in1[i] ^ opc[i];
/* tmp2 = TEMP ^ tmp1 */
XOR(tmp2, temp, tmp1, 16);
/* tmp2 = E[tmp2]k */
l_cipher_encrypt(aes, tmp2, tmp1, 16);
/* out1 = OUT1 = tmp1 ^ opc */
XOR(out1, tmp1, opc, 16);
memcpy(auts + 6, in1 + 8, 8);
return -1;
}
/* AUTN = (SQN ^ AK) | AMF | MAC_A */
XOR(autn, sqn, out2, 6);
memcpy(autn + 6, amf, 2);
memcpy(autn + 8, out1, 8);
if (memcmp(autn, autn_in, 16))
return -2;
/*
* f3 outputs CK (OUT3)
*
* tmp1 = rot(TEMP ^ OPc)r3
*
* r3 = 32 bits = 4 bytes
*/
for (i = 0; i < 16; i++)
tmp1[(i + 12) % 16] = temp[i] ^ opc[i];
/* tmp1 ^ c3. c3 at bit 126 == 1 */
tmp1[15] ^= 1 << 1;
l_cipher_encrypt(aes, tmp1, ck, 16);
/* ck ^ opc */
XOR(ck, ck, opc, 16);
/*
* f4 outputs IK (OUT4)
*
* tmp1 = rot(TEMP ^ OPc)r4
*
* r4 = 64 bits = 8 bytes
*/
for (i = 0; i < 16; i++)
tmp1[(i + 8) % 16] = temp[i] ^ opc[i];
/* tmp1 ^ c4. c4 at bit 125 == 1 */
tmp1[15] ^= 1 << 2;
l_cipher_encrypt(aes, tmp1, ik, 16);
/* ik ^ opc */
XOR(ik, ik, opc, 16);
l_cipher_free(aes);
return 0;
}
static int check_milenage(struct iwd_sim_auth *auth, const uint8_t *rand,
const uint8_t *autn, sim_auth_check_milenage_cb_t cb,
void *data)
{
uint8_t res[8];
uint8_t ck[16];
uint8_t ik[16];
uint8_t _autn[16];
uint8_t auts[14];
int ret;
if (!sim->aka_supported)
return -ENOTSUP;
ret = get_milenage(sim->opc, sim->ki, rand, sim->sqn, sim->amf,
autn, _autn, ck, ik, res, auts);
/* ret == 0, success; ret == -1, sync failure; ret == -2, failure */
if (ret == 0)
cb(res, ck, ik, NULL, data);
else if (ret == -1)
cb(NULL, NULL, NULL, auts, data);
else
cb(NULL, NULL, NULL, NULL, data);
return 0;
}
static int run_gsm(struct iwd_sim_auth *auth, const uint8_t *rands,
int num_rands, sim_auth_run_gsm_cb_t cb, void *data)
{
if (!sim->sim_supported)
return -ENOTSUP;
cb((const uint8_t *)sim->sres, (const uint8_t *)sim->kc, data);
return 0;
}
static struct iwd_sim_auth_driver hardcoded_sim_driver = {
.name = "Hardcoded SIM driver",
.check_milenage = check_milenage,
.run_gsm = run_gsm
};
static int sim_hardcoded_init(void)
{
void *kc;
void *sres;
void *ki;
void *opc;
void *amf;
void *sqn;
const char *str;
size_t len;
struct l_settings *key_settings;
const char *config_path = getenv("IWD_SIM_KEYS");
if (!config_path) {
l_debug("IWD_SIM_KEYS not set in env");
return -ENOENT;
}
key_settings = l_settings_new();
if (!l_settings_load_from_file(key_settings, config_path)) {
l_error("No %s file found", config_path);
l_settings_free(key_settings);
return -ENOENT;
}
sim = l_new(struct hardcoded_sim, 1);
if (l_settings_has_group(key_settings, "SIM")) {
str = l_settings_get_value(key_settings, "SIM", "Kc");
if (!str) {
l_debug("Kc value must be present for SIM");
goto try_aka;
}
kc = l_util_from_hexstring(str, &len);
memcpy(sim->kc, kc, len);
l_free(kc);
str = l_settings_get_value(key_settings, "SIM", "SRES");
if (!str) {
l_debug("SRES value must be present for SIM");
goto try_aka;
}
sres = l_util_from_hexstring(str, &len);
memcpy(sim->sres, sres, NUM_RANDS_MAX * EAP_SIM_SRES_LEN);
l_free(sres);
str = l_settings_get_value(key_settings, "SIM", "Identity");
if (!str) {
l_debug("Identity setting must be present for SIM");
goto try_aka;
}
sim->identity = l_strdup(str);
sim->sim_supported = 1;
}
try_aka:
if (l_settings_has_group(key_settings, "AKA")) {
str = l_settings_get_value(key_settings, "AKA", "KI");
if (!str) {
l_debug("KI value must be present for AKA");
goto end;
}
ki = l_util_from_hexstring(str, &len);
memcpy(sim->ki, ki, EAP_AKA_KI_LEN);
l_free(ki);
str = l_settings_get_value(key_settings, "AKA", "OPC");
if (!str) {
l_debug("OPC value must be preset for AKA");
goto end;
}
opc = l_util_from_hexstring(str, &len);
memcpy(sim->opc, opc, EAP_AKA_OPC_LEN);
l_free(opc);
str = l_settings_get_value(key_settings, "AKA", "AMF");
if (!str) {
l_debug("AMF value must be present for AKA");
goto end;
}
amf = l_util_from_hexstring(str, &len);
memcpy(sim->amf, amf, EAP_AKA_AMF_LEN);
l_free(amf);
str = l_settings_get_value(key_settings, "AKA", "SQN");
if (!str) {
l_debug("SQN value must be present for AKA");
goto end;
}
sqn = l_util_from_hexstring(str, &len);
memcpy(sim->sqn, sqn, EAP_AKA_SQN_LEN);
l_free(sqn);
str = l_settings_get_value(key_settings, "AKA", "Identity");
if (!str) {
l_debug("Identity setting must be present for AKA");
goto end;
}
sim->identity = l_strdup(str);
sim->aka_supported = 1;
}
end:
l_settings_free(key_settings);
if (!sim->sim_supported && !sim->aka_supported) {
l_debug("error parsing config file, values missing");
return -EINVAL;
}
sim->auth = iwd_sim_auth_create(&hardcoded_sim_driver);
iwd_sim_auth_set_nai(sim->auth, sim->identity);
iwd_sim_auth_set_capabilities(sim->auth, sim->sim_supported,
sim->aka_supported);
iwd_sim_auth_register(sim->auth);
return 0;
}
static void sim_hardcoded_exit(void)
{
iwd_sim_auth_remove(sim->auth);
if (sim)
l_free(sim->identity);
l_free(sim);
}
L_PLUGIN_DEFINE(__iwd_builtin_sim_hardcoded, sim_hardcoded,
"Hardcoded SIM driver", "1.0", L_PLUGIN_PRIORITY_DEFAULT,
sim_hardcoded_init, sim_hardcoded_exit)