/*
*
* BlueZ - Bluetooth protocol stack 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
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <linux/if_alg.h>
#include <glib.h>
#ifndef SOL_ALG
#define SOL_ALG 279
#endif
#ifndef ALG_SET_AEAD_AUTHSIZE
#define ALG_SET_AEAD_AUTHSIZE 5
#endif
#include "src/shared/util.h"
#include "tools/mesh/mesh-net.h"
#include "tools/mesh/crypto.h"
static int alg_new(int fd, const void *keyval, socklen_t keylen,
size_t mic_size)
{
if (setsockopt(fd, SOL_ALG, ALG_SET_KEY, keyval, keylen) < 0) {
g_printerr("key");
return -1;
}
if (mic_size &&
setsockopt(fd, SOL_ALG,
ALG_SET_AEAD_AUTHSIZE, NULL, mic_size) < 0) {
g_printerr("taglen");
return -1;
}
/* FIXME: This should use accept4() with SOCK_CLOEXEC */
return accept(fd, NULL, 0);
}
static bool alg_encrypt(int fd, const void *inbuf, size_t inlen,
void *outbuf, size_t outlen)
{
__u32 alg_op = ALG_OP_ENCRYPT;
char cbuf[CMSG_SPACE(sizeof(alg_op))];
struct cmsghdr *cmsg;
struct msghdr msg;
struct iovec iov;
ssize_t len;
memset(cbuf, 0, sizeof(cbuf));
memset(&msg, 0, sizeof(msg));
msg.msg_control = cbuf;
msg.msg_controllen = sizeof(cbuf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_ALG;
cmsg->cmsg_type = ALG_SET_OP;
cmsg->cmsg_len = CMSG_LEN(sizeof(alg_op));
memcpy(CMSG_DATA(cmsg), &alg_op, sizeof(alg_op));
iov.iov_base = (void *) inbuf;
iov.iov_len = inlen;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
len = sendmsg(fd, &msg, 0);
if (len < 0)
return false;
len = read(fd, outbuf, outlen);
if (len < 0)
return false;
return true;
}
static int aes_ecb_setup(const uint8_t key[16])
{
struct sockaddr_alg salg;
int fd, nfd;
fd = socket(PF_ALG, SOCK_SEQPACKET | SOCK_CLOEXEC, 0);
if (fd < 0)
return -1;
memset(&salg, 0, sizeof(salg));
salg.salg_family = AF_ALG;
strcpy((char *) salg.salg_type, "skcipher");
strcpy((char *) salg.salg_name, "ecb(aes)");
if (bind(fd, (struct sockaddr *) &salg, sizeof(salg)) < 0) {
close(fd);
return -1;
}
nfd = alg_new(fd, key, 16, 0);
close(fd);
return nfd;
}
static bool aes_ecb(int fd, const uint8_t plaintext[16], uint8_t encrypted[16])
{
return alg_encrypt(fd, plaintext, 16, encrypted, 16);
}
static void aes_ecb_destroy(int fd)
{
close(fd);
}
static bool aes_ecb_one(const uint8_t key[16],
const uint8_t plaintext[16], uint8_t encrypted[16])
{
bool result;
int fd;
fd = aes_ecb_setup(key);
if (fd < 0)
return false;
result = aes_ecb(fd, plaintext, encrypted);
aes_ecb_destroy(fd);
return result;
}
/* Maximum message length that can be passed to aes_cmac */
#define CMAC_MSG_MAX (64 + 64 + 17)
static int aes_cmac_setup(const uint8_t key[16])
{
struct sockaddr_alg salg;
int fd, nfd;
fd = socket(PF_ALG, SOCK_SEQPACKET | SOCK_CLOEXEC, 0);
if (fd < 0)
return -1;
memset(&salg, 0, sizeof(salg));
salg.salg_family = AF_ALG;
strcpy((char *) salg.salg_type, "hash");
strcpy((char *) salg.salg_name, "cmac(aes)");
if (bind(fd, (struct sockaddr *) &salg, sizeof(salg)) < 0) {
close(fd);
return -1;
}
nfd = alg_new(fd, key, 16, 0);
close(fd);
return nfd;
}
static bool aes_cmac(int fd, const uint8_t *msg,
size_t msg_len, uint8_t res[16])
{
ssize_t len;
if (msg_len > CMAC_MSG_MAX)
return false;
len = send(fd, msg, msg_len, 0);
if (len < 0)
return false;
len = read(fd, res, 16);
if (len < 0)
return false;
return true;
}
static void aes_cmac_destroy(int fd)
{
close(fd);
}
static int aes_cmac_N_start(const uint8_t N[16])
{
int fd;
fd = aes_cmac_setup(N);
return fd;
}
static bool aes_cmac_one(const uint8_t key[16], const void *msg,
size_t msg_len, uint8_t res[16])
{
bool result;
int fd;
fd = aes_cmac_setup(key);
if (fd < 0)
return false;
result = aes_cmac(fd, msg, msg_len, res);
aes_cmac_destroy(fd);
return result;
}
bool mesh_crypto_aes_cmac(const uint8_t key[16], const uint8_t *msg,
size_t msg_len, uint8_t res[16])
{
return aes_cmac_one(key, msg, msg_len, res);
}
bool mesh_crypto_aes_ccm_encrypt(const uint8_t nonce[13], const uint8_t key[16],
const uint8_t *aad, uint16_t aad_len,
const uint8_t *msg, uint16_t msg_len,
uint8_t *out_msg, void *out_mic,
size_t mic_size)
{
uint8_t pmsg[16], cmic[16], cmsg[16];
uint8_t mic[16], Xn[16];
uint16_t blk_cnt, last_blk;
bool result;
size_t i, j;
int fd;
if (aad_len >= 0xff00) {
g_printerr("Unsupported AAD size");
return false;
}
fd = aes_ecb_setup(key);
if (fd < 0)
return false;
/* C_mic = e(AppKey, 0x01 || nonce || 0x0000) */
pmsg[0] = 0x01;
memcpy(pmsg + 1, nonce, 13);
put_be16(0x0000, pmsg + 14);
result = aes_ecb(fd, pmsg, cmic);
if (!result)
goto done;
/* X_0 = e(AppKey, 0x09 || nonce || length) */
if (mic_size == sizeof(uint64_t))
pmsg[0] = 0x19 | (aad_len ? 0x40 : 0x00);
else
pmsg[0] = 0x09 | (aad_len ? 0x40 : 0x00);
memcpy(pmsg + 1, nonce, 13);
put_be16(msg_len, pmsg + 14);
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
/* If AAD is being used to authenticate, include it here */
if (aad_len) {
put_be16(aad_len, pmsg);
for (i = 0; i < sizeof(uint16_t); i++)
pmsg[i] = Xn[i] ^ pmsg[i];
j = 0;
aad_len += sizeof(uint16_t);
while (aad_len > 16) {
do {
pmsg[i] = Xn[i] ^ aad[j];
i++, j++;
} while (i < 16);
aad_len -= 16;
i = 0;
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
}
for (i = 0; i < aad_len; i++, j++)
pmsg[i] = Xn[i] ^ aad[j];
for (i = aad_len; i < 16; i++)
pmsg[i] = Xn[i];
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
}
last_blk = msg_len % 16;
blk_cnt = (msg_len + 15) / 16;
if (!last_blk)
last_blk = 16;
for (j = 0; j < blk_cnt; j++) {
if (j + 1 == blk_cnt) {
/* X_1 = e(AppKey, X_0 ^ Payload[0-15]) */
for (i = 0; i < last_blk; i++)
pmsg[i] = Xn[i] ^ msg[(j * 16) + i];
for (i = last_blk; i < 16; i++)
pmsg[i] = Xn[i] ^ 0x00;
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
/* MIC = C_mic ^ X_1 */
for (i = 0; i < sizeof(mic); i++)
mic[i] = cmic[i] ^ Xn[i];
/* C_1 = e(AppKey, 0x01 || nonce || 0x0001) */
pmsg[0] = 0x01;
memcpy(pmsg + 1, nonce, 13);
put_be16(j + 1, pmsg + 14);
result = aes_ecb(fd, pmsg, cmsg);
if (!result)
goto done;
if (out_msg) {
/* Encrypted = Payload[0-15] ^ C_1 */
for (i = 0; i < last_blk; i++)
out_msg[(j * 16) + i] =
msg[(j * 16) + i] ^ cmsg[i];
}
} else {
/* X_1 = e(AppKey, X_0 ^ Payload[0-15]) */
for (i = 0; i < 16; i++)
pmsg[i] = Xn[i] ^ msg[(j * 16) + i];
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
/* C_1 = e(AppKey, 0x01 || nonce || 0x0001) */
pmsg[0] = 0x01;
memcpy(pmsg + 1, nonce, 13);
put_be16(j + 1, pmsg + 14);
result = aes_ecb(fd, pmsg, cmsg);
if (!result)
goto done;
if (out_msg) {
/* Encrypted = Payload[0-15] ^ C_N */
for (i = 0; i < 16; i++)
out_msg[(j * 16) + i] =
msg[(j * 16) + i] ^ cmsg[i];
}
}
}
if (out_msg)
memcpy(out_msg + msg_len, mic, mic_size);
if (out_mic) {
switch (mic_size) {
case sizeof(uint32_t):
*(uint32_t *)out_mic = get_be32(mic);
break;
case sizeof(uint64_t):
*(uint64_t *)out_mic = get_be64(mic);
break;
default:
g_printerr("Unsupported MIC size");
}
}
done:
aes_ecb_destroy(fd);
return result;
}
bool mesh_crypto_aes_ccm_decrypt(const uint8_t nonce[13], const uint8_t key[16],
const uint8_t *aad, uint16_t aad_len,
const uint8_t *enc_msg, uint16_t enc_msg_len,
uint8_t *out_msg, void *out_mic,
size_t mic_size)
{
uint8_t msg[16], pmsg[16], cmic[16], cmsg[16], Xn[16];
uint8_t mic[16];
uint16_t msg_len = enc_msg_len - mic_size;
uint16_t last_blk, blk_cnt;
bool result;
size_t i, j;
int fd;
if (enc_msg_len < 5 || aad_len >= 0xff00)
return false;
fd = aes_ecb_setup(key);
if (fd < 0)
return false;
/* C_mic = e(AppKey, 0x01 || nonce || 0x0000) */
pmsg[0] = 0x01;
memcpy(pmsg + 1, nonce, 13);
put_be16(0x0000, pmsg + 14);
result = aes_ecb(fd, pmsg, cmic);
if (!result)
goto done;
/* X_0 = e(AppKey, 0x09 || nonce || length) */
if (mic_size == sizeof(uint64_t))
pmsg[0] = 0x19 | (aad_len ? 0x40 : 0x00);
else
pmsg[0] = 0x09 | (aad_len ? 0x40 : 0x00);
memcpy(pmsg + 1, nonce, 13);
put_be16(msg_len, pmsg + 14);
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
/* If AAD is being used to authenticate, include it here */
if (aad_len) {
put_be16(aad_len, pmsg);
for (i = 0; i < sizeof(uint16_t); i++)
pmsg[i] = Xn[i] ^ pmsg[i];
j = 0;
aad_len += sizeof(uint16_t);
while (aad_len > 16) {
do {
pmsg[i] = Xn[i] ^ aad[j];
i++, j++;
} while (i < 16);
aad_len -= 16;
i = 0;
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
}
for (i = 0; i < aad_len; i++, j++)
pmsg[i] = Xn[i] ^ aad[j];
for (i = aad_len; i < 16; i++)
pmsg[i] = Xn[i];
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
}
last_blk = msg_len % 16;
blk_cnt = (msg_len + 15) / 16;
if (!last_blk)
last_blk = 16;
for (j = 0; j < blk_cnt; j++) {
if (j + 1 == blk_cnt) {
/* C_1 = e(AppKey, 0x01 || nonce || 0x0001) */
pmsg[0] = 0x01;
memcpy(pmsg + 1, nonce, 13);
put_be16(j + 1, pmsg + 14);
result = aes_ecb(fd, pmsg, cmsg);
if (!result)
goto done;
/* Encrypted = Payload[0-15] ^ C_1 */
for (i = 0; i < last_blk; i++)
msg[i] = enc_msg[(j * 16) + i] ^ cmsg[i];
if (out_msg)
memcpy(out_msg + (j * 16), msg, last_blk);
/* X_1 = e(AppKey, X_0 ^ Payload[0-15]) */
for (i = 0; i < last_blk; i++)
pmsg[i] = Xn[i] ^ msg[i];
for (i = last_blk; i < 16; i++)
pmsg[i] = Xn[i] ^ 0x00;
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
/* MIC = C_mic ^ X_1 */
for (i = 0; i < sizeof(mic); i++)
mic[i] = cmic[i] ^ Xn[i];
} else {
/* C_1 = e(AppKey, 0x01 || nonce || 0x0001) */
pmsg[0] = 0x01;
memcpy(pmsg + 1, nonce, 13);
put_be16(j + 1, pmsg + 14);
result = aes_ecb(fd, pmsg, cmsg);
if (!result)
goto done;
/* Encrypted = Payload[0-15] ^ C_1 */
for (i = 0; i < 16; i++)
msg[i] = enc_msg[(j * 16) + i] ^ cmsg[i];
if (out_msg)
memcpy(out_msg + (j * 16), msg, 16);
/* X_1 = e(AppKey, X_0 ^ Payload[0-15]) */
for (i = 0; i < 16; i++)
pmsg[i] = Xn[i] ^ msg[i];
result = aes_ecb(fd, pmsg, Xn);
if (!result)
goto done;
}
}
switch (mic_size) {
case sizeof(uint32_t):
if (out_mic)
*(uint32_t *)out_mic = get_be32(mic);
else if (get_be32(enc_msg + enc_msg_len - mic_size) !=
get_be32(mic))
result = false;
break;
case sizeof(uint64_t):
if (out_mic)
*(uint64_t *)out_mic = get_be64(mic);
else if (get_be64(enc_msg + enc_msg_len - mic_size) !=
get_be64(mic))
result = false;
break;
default:
g_printerr("Unsupported MIC size");
result = false;
}
done:
aes_ecb_destroy(fd);
return result;
}
bool mesh_crypto_k1(const uint8_t ikm[16], const uint8_t salt[16],
const void *info, size_t info_len, uint8_t okm[16])
{
uint8_t res[16];
if (!aes_cmac_one(salt, ikm, 16, res))
return false;
return aes_cmac_one(res, info, info_len, okm);
}
bool mesh_crypto_k2(const uint8_t n[16], const uint8_t *p, size_t p_len,
uint8_t net_id[1],
uint8_t enc_key[16],
uint8_t priv_key[16])
{
int fd;
uint8_t output[16];
uint8_t t[16];
uint8_t *stage;
bool success = false;
stage = g_malloc(sizeof(output) + p_len + 1);
if (stage == NULL)
return false;
if (!mesh_crypto_s1("smk2", 4, stage))
goto fail;
if (!aes_cmac_one(stage, n, 16, t))
goto fail;
fd = aes_cmac_N_start(t);
if (fd < 0)
goto fail;
memcpy(stage, p, p_len);
stage[p_len] = 1;
if(!aes_cmac(fd, stage, p_len + 1, output))
goto done;
net_id[0] = output[15] & 0x7f;
memcpy(stage, output, 16);
memcpy(stage + 16, p, p_len);
stage[p_len + 16] = 2;
if(!aes_cmac(fd, stage, p_len + 16 + 1, output))
goto done;
memcpy(enc_key, output, 16);
memcpy(stage, output, 16);
memcpy(stage + 16, p, p_len);
stage[p_len + 16] = 3;
if(!aes_cmac(fd, stage, p_len + 16 + 1, output))
goto done;
memcpy(priv_key, output, 16);
success = true;
done:
aes_cmac_destroy(fd);
fail:
g_free(stage);
return success;
}
static bool crypto_128(const uint8_t n[16], const char *s, uint8_t out128[16])
{
uint8_t id128[] = { 'i', 'd', '1', '2', '8', 0x01 };
uint8_t salt[16];
if (!mesh_crypto_s1(s, 4, salt))
return false;
return mesh_crypto_k1(n, salt, id128, sizeof(id128), out128);
}
bool mesh_crypto_nkik(const uint8_t n[16], uint8_t identity_key[16])
{
return crypto_128(n, "nkik", identity_key);
}
static bool identity_calc(const uint8_t net_key[16], uint16_t addr,
bool check, uint8_t id[16])
{
uint8_t id_key[16];
uint8_t tmp[16];
if (!mesh_crypto_nkik(net_key, id_key))
return false;
memset(tmp, 0, sizeof(tmp));
put_be16(addr, tmp + 14);
if (check) {
memcpy(tmp + 6, id + 8, 8);
} else {
mesh_get_random_bytes(tmp + 6, 8);
memcpy(id + 8, tmp + 6, 8);
}
if (!aes_ecb_one(id_key, tmp, tmp))
return false;
if (check)
return (memcmp(id, tmp + 8, 8) == 0);
memcpy(id, tmp + 8, 8);
return true;
}
bool mesh_crypto_identity(const uint8_t net_key[16], uint16_t addr,
uint8_t id[16])
{
return identity_calc(net_key, addr, false, id);
}
bool mesh_crypto_identity_check(const uint8_t net_key[16], uint16_t addr,
uint8_t id[16])
{
return identity_calc(net_key, addr, true, id);
}
bool mesh_crypto_nkbk(const uint8_t n[16], uint8_t beacon_key[16])
{
return crypto_128(n, "nkbk", beacon_key);
}
bool mesh_crypto_k3(const uint8_t n[16], uint8_t out64[8])
{
uint8_t tmp[16];
uint8_t t[16];
uint8_t id64[] = { 'i', 'd', '6', '4', 0x01 };
if (!mesh_crypto_s1("smk3", 4, tmp))
return false;
if (!aes_cmac_one(tmp, n, 16, t))
return false;
if (!aes_cmac_one(t, id64, sizeof(id64), tmp))
return false;
memcpy(out64, tmp + 8, 8);
return true;
}
bool mesh_crypto_k4(const uint8_t a[16], uint8_t out6[1])
{
uint8_t tmp[16];
uint8_t t[16];
uint8_t id6[] = { 'i', 'd', '6', 0x01 };
if (!mesh_crypto_s1("smk4", 4, tmp))
return false;
if (!aes_cmac_one(tmp, a, 16, t))
return false;
if (!aes_cmac_one(t, id6, sizeof(id6), tmp))
return false;
out6[0] = tmp[15] & 0x3f;
return true;
}
bool mesh_crypto_beacon_cmac(const uint8_t encryption_key[16],
const uint8_t network_id[8],
uint32_t iv_index, bool kr, bool iu,
uint64_t *cmac)
{
uint8_t msg[13], tmp[16];
if (!cmac)
return false;
msg[0] = kr ? 0x01 : 0x00;
msg[0] |= iu ? 0x02 : 0x00;
memcpy(msg + 1, network_id, 8);
put_be32(iv_index, msg + 9);
if (!aes_cmac_one(encryption_key, msg, 13, tmp))
return false;
*cmac = get_be64(tmp);
return true;
}
bool mesh_crypto_network_nonce(bool ctl, uint8_t ttl, uint32_t seq,
uint16_t src, uint32_t iv_index,
uint8_t nonce[13])
{
nonce[0] = 0;
nonce[1] = (ttl & TTL_MASK) | (ctl ? CTL : 0x00);
nonce[2] = (seq >> 16) & 0xff;
nonce[3] = (seq >> 8) & 0xff;
nonce[4] = seq & 0xff;
/* SRC */
put_be16(src, nonce + 5);
put_be16(0, nonce + 7);
/* IV Index */
put_be32(iv_index, nonce + 9);
return true;
}
bool mesh_crypto_network_encrypt(bool ctl, uint8_t ttl,
uint32_t seq, uint16_t src,
uint32_t iv_index,
const uint8_t net_key[16],
const uint8_t *enc_msg, uint8_t enc_msg_len,
uint8_t *out, void *net_mic)
{
uint8_t nonce[13];
if (!mesh_crypto_network_nonce(ctl, ttl, seq, src, iv_index, nonce))
return false;
return mesh_crypto_aes_ccm_encrypt(nonce, net_key,
NULL, 0, enc_msg,
enc_msg_len, out,
net_mic,
ctl ? sizeof(uint64_t) : sizeof(uint32_t));
}
bool mesh_crypto_network_decrypt(bool ctl, uint8_t ttl,
uint32_t seq, uint16_t src,
uint32_t iv_index,
const uint8_t net_key[16],
const uint8_t *enc_msg, uint8_t enc_msg_len,
uint8_t *out, void *net_mic, size_t mic_size)
{
uint8_t nonce[13];
if (!mesh_crypto_network_nonce(ctl, ttl, seq, src, iv_index, nonce))
return false;
return mesh_crypto_aes_ccm_decrypt(nonce, net_key, NULL, 0,
enc_msg, enc_msg_len, out,
net_mic, mic_size);
}
bool mesh_crypto_application_nonce(uint32_t seq, uint16_t src,
uint16_t dst, uint32_t iv_index,
bool aszmic, uint8_t nonce[13])
{
nonce[0] = 0x01;
nonce[1] = aszmic ? 0x80 : 0x00;
nonce[2] = (seq & 0x00ff0000) >> 16;
nonce[3] = (seq & 0x0000ff00) >> 8;
nonce[4] = (seq & 0x000000ff);
nonce[5] = (src & 0xff00) >> 8;
nonce[6] = (src & 0x00ff);
nonce[7] = (dst & 0xff00) >> 8;
nonce[8] = (dst & 0x00ff);
put_be32(iv_index, nonce + 9);
return true;
}
bool mesh_crypto_device_nonce(uint32_t seq, uint16_t src,
uint16_t dst, uint32_t iv_index,
bool aszmic, uint8_t nonce[13])
{
nonce[0] = 0x02;
nonce[1] = aszmic ? 0x80 : 0x00;
nonce[2] = (seq & 0x00ff0000) >> 16;
nonce[3] = (seq & 0x0000ff00) >> 8;
nonce[4] = (seq & 0x000000ff);
nonce[5] = (src & 0xff00) >> 8;
nonce[6] = (src & 0x00ff);
nonce[7] = (dst & 0xff00) >> 8;
nonce[8] = (dst & 0x00ff);
put_be32(iv_index, nonce + 9);
return true;
}
bool mesh_crypto_application_encrypt(uint8_t key_id, uint32_t seq, uint16_t src,
uint16_t dst, uint32_t iv_index,
const uint8_t app_key[16],
const uint8_t *aad, uint8_t aad_len,
const uint8_t *msg, uint8_t msg_len,
uint8_t *out, void *app_mic,
size_t mic_size)
{
uint8_t nonce[13];
bool aszmic = (mic_size == sizeof(uint64_t)) ? true : false;
if (!key_id && !mesh_crypto_device_nonce(seq, src, dst,
iv_index, aszmic, nonce))
return false;
if (key_id && !mesh_crypto_application_nonce(seq, src, dst,
iv_index, aszmic, nonce))
return false;
return mesh_crypto_aes_ccm_encrypt(nonce, app_key, aad, aad_len,
msg, msg_len,
out, app_mic, mic_size);
}
bool mesh_crypto_application_decrypt(uint8_t key_id, uint32_t seq, uint16_t src,
uint16_t dst, uint32_t iv_index,
const uint8_t app_key[16],
const uint8_t *aad, uint8_t aad_len,
const uint8_t *enc_msg, uint8_t enc_msg_len,
uint8_t *out, void *app_mic, size_t mic_size)
{
uint8_t nonce[13];
bool aszmic = (mic_size == sizeof(uint64_t)) ? true : false;
if (!key_id && !mesh_crypto_device_nonce(seq, src, dst,
iv_index, aszmic, nonce))
return false;
if (key_id && !mesh_crypto_application_nonce(seq, src, dst,
iv_index, aszmic, nonce))
return false;
return mesh_crypto_aes_ccm_decrypt(nonce, app_key,
aad, aad_len, enc_msg,
enc_msg_len, out,
app_mic, mic_size);
}
bool mesh_crypto_session_key(const uint8_t secret[32],
const uint8_t salt[16],
uint8_t session_key[16])
{
const uint8_t prsk[4] = "prsk";
if (!aes_cmac_one(salt, secret, 32, session_key))
return false;
return aes_cmac_one(session_key, prsk, 4, session_key);
}
bool mesh_crypto_nonce(const uint8_t secret[32],
const uint8_t salt[16],
uint8_t nonce[13])
{
const uint8_t prsn[4] = "prsn";
uint8_t tmp[16];
bool result;
if (!aes_cmac_one(salt, secret, 32, tmp))
return false;
result = aes_cmac_one(tmp, prsn, 4, tmp);
if (result)
memcpy(nonce, tmp + 3, 13);
return result;
}
bool mesh_crypto_s1(const void *info, size_t len, uint8_t salt[16])
{
const uint8_t zero[16] = {0};
return aes_cmac_one(zero, info, len, salt);
}
bool mesh_crypto_prov_prov_salt(const uint8_t conf_salt[16],
const uint8_t prov_rand[16],
const uint8_t dev_rand[16],
uint8_t prov_salt[16])
{
const uint8_t zero[16] = {0};
uint8_t tmp[16 * 3];
memcpy(tmp, conf_salt, 16);
memcpy(tmp + 16, prov_rand, 16);
memcpy(tmp + 32, dev_rand, 16);
return aes_cmac_one(zero, tmp, sizeof(tmp), prov_salt);
}
bool mesh_crypto_prov_conf_key(const uint8_t secret[32],
const uint8_t salt[16],
uint8_t conf_key[16])
{
const uint8_t prck[4] = "prck";
if (!aes_cmac_one(salt, secret, 32, conf_key))
return false;
return aes_cmac_one(conf_key, prck, 4, conf_key);
}
bool mesh_crypto_device_key(const uint8_t secret[32],
const uint8_t salt[16],
uint8_t device_key[16])
{
const uint8_t prdk[4] = "prdk";
if (!aes_cmac_one(salt, secret, 32, device_key))
return false;
return aes_cmac_one(device_key, prdk, 4, device_key);
}
bool mesh_crypto_virtual_addr(const uint8_t virtual_label[16],
uint16_t *addr)
{
uint8_t tmp[16];
if (!mesh_crypto_s1("vtad", 4, tmp))
return false;
if (!addr || !aes_cmac_one(tmp, virtual_label, 16, tmp))
return false;
*addr = (get_be16(tmp + 14) & 0x3fff) | 0x8000;
return true;
}
bool mesh_crypto_packet_encode(uint8_t *packet, uint8_t packet_len,
const uint8_t network_key[16],
uint32_t iv_index,
const uint8_t privacy_key[16])
{
uint8_t network_nonce[13] = { 0x00, 0x00 };
uint8_t privacy_counter[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, };
uint8_t tmp[16];
int i;
/* Detect Proxy packet by CTL == true && DST == 0x0000 */
if ((packet[1] & CTL) && get_be16(packet + 7) == 0)
network_nonce[0] = 0x03;
else
/* CTL + TTL */
network_nonce[1] = packet[1];
/* Seq Num */
network_nonce[2] = packet[2];
network_nonce[3] = packet[3];
network_nonce[4] = packet[4];
/* SRC */
network_nonce[5] = packet[5];
network_nonce[6] = packet[6];
/* DST not available */
network_nonce[7] = 0;
network_nonce[8] = 0;
/* IV Index */
put_be32(iv_index, network_nonce + 9);
/* Check for Long net-MIC */
if (packet[1] & CTL) {
if (!mesh_crypto_aes_ccm_encrypt(network_nonce, network_key,
NULL, 0,
packet + 7, packet_len - 7 - 8,
packet + 7, NULL, sizeof(uint64_t)))
return false;
} else {
if (!mesh_crypto_aes_ccm_encrypt(network_nonce, network_key,
NULL, 0,
packet + 7, packet_len - 7 - 4,
packet + 7, NULL, sizeof(uint32_t)))
return false;
}
put_be32(iv_index, privacy_counter + 5);
memcpy(privacy_counter + 9, packet + 7, 7);
if (!aes_ecb_one(privacy_key, privacy_counter, tmp))
return false;
for (i = 0; i < 6; i++)
packet[1 + i] ^= tmp[i];
return true;
}
bool mesh_crypto_packet_decode(const uint8_t *packet, uint8_t packet_len,
bool proxy, uint8_t *out, uint32_t iv_index,
const uint8_t network_key[16],
const uint8_t privacy_key[16])
{
uint8_t privacy_counter[16] = { 0x00, 0x00, 0x00, 0x00, 0x00, };
uint8_t network_nonce[13] = { 0x00, 0x00, };
uint8_t tmp[16];
uint16_t src;
int i;
if (packet_len < 14)
return false;
put_be32(iv_index, privacy_counter + 5);
memcpy(privacy_counter + 9, packet + 7, 7);
if (!aes_ecb_one(privacy_key, privacy_counter, tmp))
return false;
memcpy(out, packet, packet_len);
for (i = 0; i < 6; i++)
out[1 + i] ^= tmp[i];
src = get_be16(out + 5);
/* Pre-check SRC address for illegal values */
if (!src || src >= 0x8000)
return false;
/* Detect Proxy packet by CTL == true && proxy == true */
if ((out[1] & CTL) && proxy)
network_nonce[0] = 0x03;
else
/* CTL + TTL */
network_nonce[1] = out[1];
/* Seq Num */
network_nonce[2] = out[2];
network_nonce[3] = out[3];
network_nonce[4] = out[4];
/* SRC */
network_nonce[5] = out[5];
network_nonce[6] = out[6];
/* DST not available */
network_nonce[7] = 0;
network_nonce[8] = 0;
/* IV Index */
put_be32(iv_index, network_nonce + 9);
/* Check for Long MIC */
if (out[1] & CTL) {
uint64_t mic;
if (!mesh_crypto_aes_ccm_decrypt(network_nonce, network_key,
NULL, 0, packet + 7, packet_len - 7,
out + 7, &mic, sizeof(mic)))
return false;
mic ^= get_be64(out + packet_len - 8);
put_be64(mic, out + packet_len - 8);
if (mic)
return false;
} else {
uint32_t mic;
if (!mesh_crypto_aes_ccm_decrypt(network_nonce, network_key,
NULL, 0, packet + 7, packet_len - 7,
out + 7, &mic, sizeof(mic)))
return false;
mic ^= get_be32(out + packet_len - 4);
put_be32(mic, out + packet_len - 4);
if (mic)
return false;
}
return true;
}
bool mesh_get_random_bytes(void *buf, size_t num_bytes)
{
ssize_t len;
int fd;
fd = open("/dev/urandom", O_RDONLY);
if (fd < 0)
return false;
len = read(fd, buf, num_bytes);
close(fd);
if (len < 0)
return false;
return true;
}