// SPDX-License-Identifier: LGPL-2.1-or-later /* * * BlueZ - Bluetooth protocol stack for Linux * * Copyright (C) 2017 Intel Corporation. All rights reserved. * * */ #ifdef HAVE_CONFIG_H #include #endif #include #include #include #include #include #include #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-gatt/mesh-net.h" #include "tools/mesh-gatt/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; }