| /* |
| * Copyright 2017 The Chromium OS Authors. All rights reserved. |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| #include <stdlib.h> |
| #include <string.h> |
| #include <time.h> |
| |
| #include "bt.h" |
| #include "config.h" |
| #include "l2cap.h" |
| #include "log.h" |
| #include "mt.h" |
| #include "persist.h" |
| #include "sendQ.h" |
| #include "sg.h" |
| #include "timer.h" |
| #include "types.h" |
| #include "util.h" |
| |
| #include "sm.h" |
| |
| #ifdef _UNITTEST_ |
| #define static_or_test |
| #else |
| #define static_or_test static |
| #endif |
| |
| /* definition of structs and macros based on Bluetooth spec v4.0 */ |
| /* packet types */ |
| #define SM_PAIRING_REQ 0x01 /* struct smPairReqResp */ |
| #define SM_PAIRING_RSP 0x02 /* struct smPairReqResp */ |
| #define SM_PAIRING_CONF 0x03 /* struct smPairConf */ |
| #define SM_PAIRING_RAND 0x04 /* struct smPairRand */ |
| #define SM_PAIRING_FAIL 0x05 /* struct smPairFailed */ |
| #define SM_ENCR_INFO 0x06 /* struct smKey => LTK */ |
| #define SM_MASTER_INFO 0x07 /* struct smMasterInfo */ |
| #define SM_IDENTITY_INFO 0x08 /* struct smKey => IRK */ |
| #define SM_IDENTITY_ADDR_INFO 0x09 /* struct smIdentityAddrInfo */ |
| #define SM_SIGNING_INFO 0x0A /* struct smKey => CSRK */ |
| #define SM_SECURITY_REQUEST 0x0B /* struct smAuthReq */ |
| |
| struct smHdr { |
| uint8_t typ; |
| } __packed; |
| |
| struct smPairReqResp { |
| uint8_t ioCap; |
| uint8_t oobDataFlag; |
| uint8_t authReq; /* SM_AUTH_REQ_* */ |
| uint8_t maxKeySz; |
| uint8_t initiatorKeyDistr; /* bitfield of SM_KEY_DISTR_* */ |
| uint8_t responderKeyDistr; /* bitfield of SM_KEY_DISTR_* */ |
| } __packed; |
| |
| struct smPairConf { |
| uint8_t confirmVal[16]; /* [0]->[15] : MSO->LSO */ |
| } __packed; |
| |
| struct smPairRand { |
| uint8_t rand[16]; /* [0]->[15] : MSO->LSO */ |
| } __packed; |
| |
| struct smPairFailed { |
| uint8_t reason; /* SM_ERR_* */ |
| } __packed; |
| |
| struct smKey { |
| uint8_t key[16]; /* [0]->[15] : MSO->LSO */ |
| } __packed; |
| |
| struct smMasterInfo { |
| uint16_t ediv; |
| uint64_t rand; |
| } __packed; |
| |
| struct smIdentityAddrInfo { |
| uint8_t addrType; |
| uint8_t mac[6]; |
| } __packed; |
| |
| struct smAuthReq { |
| uint8_t authReq; /* SM_AUTH_REQ_* */ |
| } __packed; |
| |
| /* fail codes */ |
| #define SM_ERR_PASSKEY_ENTRY_FAILED 0x01 /* user cancelled or failed to input key */ |
| #define SM_ERR_OOB_NOT_AVAIL 0x02 /* no OOB data */ |
| #define SM_ERR_AUTH_REQMENTS 0x03 /* auth requirements cannot be met due to IO caps */ |
| #define SM_ERR_CONF_VAL_FAILED 0x04 /* confirm value does not match calculated value */ |
| #define SM_ERR_PAIRING_NOT_SUPPORTED 0x05 /* pairing not supported by this device */ |
| #define SM_ERR_ENCR_KEY_SZ 0x06 /* resulting key size is not long enough */ |
| #define SM_ERR_CMD_NOT_SUPP 0x07 /* received command not supported by this device */ |
| #define SM_ERR_UNSPECCED_REASON 0x08 /* pairing failed due to an unspecified reason */ |
| #define SM_ERR_REPEATED_ATTEMPTS 0x09 /* too rapid an attempt to pair after a failure */ |
| #define SM_ERR_INVALID_PARAMS 0x0A /* unparseable command or invalid params in command */ |
| |
| /* things for authReq fields */ |
| #define SM_AUTH_REQ_BOND_MASK 0x03 |
| #define SM_AUTH_REQ_BOND_NO 0x00 |
| #define SM_AUTH_REQ_BOND_BOND 0x01 |
| #define SM_AUTH_REQ_MITM_FLAG 0x04 |
| #define SM_AUTH_REQ_SC_FLAG 0x08 |
| #define SM_AUTH_REQ_KEYPRESS_FLAG 0x10 |
| |
| /* things for key distr fields */ |
| #define SM_KEY_DISTR_LTK 0x01 |
| #define SM_KEY_DISTR_IRK 0x02 |
| #define SM_KEY_DISTR_CSRK 0x04 |
| |
| /* misc defines */ |
| #define SM_MIN_KEY_LEN 7 |
| #define SM_MAX_KEY_LEN 16 |
| |
| |
| /* definition of structs and macros based on our implementation */ |
| #define SM_PHASE_START 0 /* nothing happened yet. */ |
| #define SM_PHASE_REQ_SENT 1 /* we sent pair req. waiting for pair resp. */ |
| #define SM_PHASE_REQ_RESP 2 /* the peer has sent us a pair request, we replied. waiting for Mconfim. OR we sent req and got resp */ |
| #define SM_PHASE_CONF_SENT 3 /* we sent Mconfirm. waiting for Sconfirm. */ |
| #define SM_PHASE_CONF_RESP 4 /* the peer has sent us Mconfirm, we replied with Sconfirm. waiting for Mrand. OR we sent Mconfirm and got Sconfim. */ |
| #define SM_PHASE_RAND_SENT 5 /* we sent Mrand. wainting for Srand. */ |
| #define SM_PHASE_RAND_RESP 6 /* other peer has sent us Mrand, we replied with Srand. OR we sent Mrand and got Srand.*/ |
| |
| #define SM_WAIT_INTVL_FACTOR 2 /* the wait interval grows exponentially with base 2 */ |
| #define SM_DEF_WAIT_INTVL 0 /* 0 sec in msec - default wait interval */ |
| #define SM_MIN_WAIT_INTVL 4000 /* 4 sec in msec - minimum wait interval */ |
| #define SM_MAX_WAIT_INTVL 64000 /* 64 sec in msec - maximum wait interval */ |
| #define SM_STALL_INTVL 30000 /* 30 sec in msec - timeout of a pairing process */ |
| |
| struct smInstance { |
| struct smInstance* prev; |
| struct smInstance* next; |
| |
| struct bt_addr peerAddr; |
| struct bt_addr myAddr; |
| l2c_handle_t conn; |
| bool isInitiator; /* whether we are the initiator */ |
| |
| uint8_t phase; |
| uniq_t stallTimer; /* the timer tracking whether a pairing session is stalled */ |
| |
| struct smKey tk; |
| struct smKey stk; |
| |
| uint8_t peerIoCap; |
| bool peerHasOob; |
| uint8_t peerAuthReq; |
| uint8_t peerMaxKeySz; |
| uint8_t peerKeyDistr; |
| struct smPairRand peerRandNum; |
| struct smPairConf peerConfVal; |
| |
| uint8_t myAuthReq; |
| uint8_t myMaxKeySz; |
| uint8_t myKeyDistr; |
| struct smPairRand myRandNum; |
| struct smPairConf myConfVal; |
| }; |
| |
| struct smDevNode { |
| struct smDevNode *prev; |
| struct smDevNode *next; |
| struct bt_addr addr; /* the address of the banned device */ |
| uniq_t devId; /* an unique ID associated with the device */ |
| |
| uint64_t waitInvl; /* the wait interval of initiating/responding the pairing */ |
| uniq_t waitTimer; /* the timer tracking the wait interval of a banned device */ |
| }; |
| |
| /* local settings and state */ |
| static uint8_t mIoCap; |
| static bool mHasOob; /* whether we support OOB data */ |
| |
| static pthread_mutex_t mInstLock = PTHREAD_MUTEX_INITIALIZER; /* lock for the active instance list */ |
| static struct smInstance *mActInstList = NULL; /* the active instances */ |
| |
| static pthread_mutex_t mDevLock = PTHREAD_MUTEX_INITIALIZER; /* lock for the banned device list */ |
| static struct smDevNode *mBannedDevList = NULL; /* the device banned on pairing */ |
| |
| /* fwd decls */ |
| static bool smGenSTK(struct smInstance *inst); |
| static bool smGenTK(struct smInstance *inst); |
| static bool smGenConfVal(struct smPairConf *conf, const struct smInstance *inst, bool check); |
| static bool smGenRandNum(struct smInstance *inst); |
| static_or_test void smEncrypt(uint8_t* dst, const uint8_t *src, const uint8_t *key); |
| |
| /* sendQ for packet transmissions */ |
| static struct sendQ *mSmSendQ; |
| |
| /* pairing algorithms */ |
| #define SM_ALG_JUST_WORK 0x00 |
| #define SM_ALG_PASS_KEY 0x01 |
| #define SM_ALG_OOB 0x02 |
| #define SM_ALG_UNKNOWN 0xFF |
| |
| /* table of pairing algorithms -mPairAlgs[responder][initiator] */ |
| static const uint8_t mPairAlgs[5][5] = { |
| {SM_ALG_JUST_WORK, SM_ALG_JUST_WORK, SM_ALG_PASS_KEY, SM_ALG_JUST_WORK, SM_ALG_PASS_KEY }, |
| {SM_ALG_JUST_WORK, SM_ALG_JUST_WORK, SM_ALG_PASS_KEY, SM_ALG_JUST_WORK, SM_ALG_PASS_KEY }, |
| {SM_ALG_PASS_KEY, SM_ALG_PASS_KEY, SM_ALG_PASS_KEY, SM_ALG_JUST_WORK, SM_ALG_PASS_KEY }, |
| {SM_ALG_JUST_WORK, SM_ALG_JUST_WORK, SM_ALG_JUST_WORK, SM_ALG_JUST_WORK, SM_ALG_JUST_WORK}, |
| {SM_ALG_PASS_KEY, SM_ALG_PASS_KEY, SM_ALG_PASS_KEY, SM_ALG_JUST_WORK, SM_ALG_PASS_KEY }, |
| }; |
| |
| /* |
| * FUNCTION: smSameAddr |
| * USE: Given two struct bt_addr, tell whether they are the same |
| * PARAMS: a - a device address |
| * b - the other device address |
| * RETURN: true if they are the same; false otherwise |
| * NOTES: |
| */ |
| static bool smSameAddr(const struct bt_addr *a, const struct bt_addr *b) |
| { |
| return !memcmp(a, b, sizeof(struct bt_addr)); |
| } |
| |
| /* |
| * FUNCTION: smBannedDevFree |
| * USE: Free the given device node |
| * PARAMS: dev - the to-be-freed device node |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smBannedDevFree(struct smDevNode *dev) |
| { |
| if (!dev) |
| return; |
| |
| if (dev->waitTimer) |
| timerCancel(dev->waitTimer); |
| |
| free(dev); |
| } |
| |
| /* |
| * FUNCTION: smBannedDevFindByAddr |
| * USE: Find a device node by the address of the device on the banned device list |
| * PARAMS: addr - the device address |
| * RETURN: the pointer to the device node if matched; NULL otherwise |
| * NOTES: call with mDevLock held |
| */ |
| static struct smDevNode* smBannedDevFindByAddr(const struct bt_addr *addr) |
| { |
| struct smDevNode *n = mBannedDevList; |
| |
| if (!addr) |
| return NULL; |
| |
| while (n) { |
| if (smSameAddr(addr, &n->addr)) |
| return n; |
| n = n->next; |
| } |
| return NULL; |
| } |
| |
| /* |
| * FUNCTION: smBannedDevFindById |
| * USE: Find a device node by the device ID on the banned device list |
| * PARAMS: id - the device ID |
| * RETURN: the pointer to the device node if matched; NULL otherwise |
| * NOTES: call with mDevLock held |
| */ |
| static struct smDevNode* smBannedDevFindById(uniq_t id) |
| { |
| struct smDevNode *n = mBannedDevList; |
| |
| if (!id) |
| return NULL; |
| |
| while (n) { |
| if (n->devId == id) |
| return n; |
| n = n->next; |
| } |
| return NULL; |
| } |
| |
| /* |
| * FUNCTION: smBannedDevDel |
| * USE: Find device node by Device ID and delete it from the banned device list if matched |
| * PARAMS: id - the device ID |
| * RETURN: NONE |
| * NOTES: call with mDevLock held |
| */ |
| static void smBannedDevDel(uniq_t id) |
| { |
| struct smDevNode *n; |
| |
| if (!id) |
| return; |
| |
| n = smBannedDevFindById(id); |
| if (!n) |
| return; |
| |
| logd("%s(): Remove device "MACFMT" from the banned list\n", __func__, MACCONV(n->addr.addr)); |
| if (n->next) |
| n->next->prev = n->prev; |
| if (n->prev) |
| n->prev->next = n->next; |
| else |
| mBannedDevList = n->next; |
| |
| smBannedDevFree(n); |
| } |
| |
| /* |
| * FUNCTION: smWaitTimerCb |
| * USE: Called when the timer with wait interval expires to allow sending a Pairing request, a |
| * Security request or a Pairing response for a banned device |
| * PARAMS: timerId - an unique ID of a timer |
| * devId - a device ID |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smWaitTimerCb(uniq_t timerId, uint64_t devId) |
| { |
| pthread_mutex_lock(&mDevLock); |
| smBannedDevDel(devId); |
| pthread_mutex_unlock(&mDevLock); |
| } |
| |
| /* |
| * FUNCTION: smBannedDevAdd |
| * USE: Add a device to the banned device list |
| * PARAMS: addr - the device address |
| * RETURN: the pointer to the device node; NULL otherwise |
| * NOTES: call with mDevLock held |
| */ |
| static struct smDevNode* smBannedDevAdd(const struct bt_addr *addr) |
| { |
| struct smDevNode *n = NULL; |
| |
| if (!addr) |
| return NULL; |
| |
| n = (struct smDevNode*)calloc(1, sizeof(struct smDevNode)); |
| if (!n) |
| return NULL; |
| |
| n->addr = *addr; |
| n->devId = uniqGetNext(); |
| n->waitInvl = SM_MIN_WAIT_INTVL; |
| n->waitTimer = timerSet(n->waitInvl, smWaitTimerCb, n->devId); |
| if (!n->waitTimer) |
| goto fail; |
| |
| if (mBannedDevList) { |
| n->next = mBannedDevList; |
| mBannedDevList->prev = n; |
| } |
| mBannedDevList = n; |
| logd("%s(): Add device "MACFMT" to the banned list\n", __func__, MACCONV(addr->addr)); |
| return n; |
| |
| fail: |
| logw("%s(): Failed to add device "MACFMT" to the banned list\n", __func__, MACCONV(addr->addr)); |
| smBannedDevFree(n); |
| return NULL; |
| } |
| |
| /* |
| * FUNCTION: smBannedDevFreeAll |
| * USE: Free all nodes of the banned device list |
| * PARAMS: NONE |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smBannedDevFreeAll(void) |
| { |
| struct smDevNode *n; |
| |
| pthread_mutex_lock(&mDevLock); |
| while(mBannedDevList) { |
| n = mBannedDevList->next; |
| smBannedDevFree(mBannedDevList); |
| mBannedDevList = n; |
| } |
| pthread_mutex_unlock(&mDevLock); |
| } |
| |
| /* |
| * FUNCTION: smBanDeviceForTime |
| * USE: Start or update the wait interval timer to prevent from sending a Pairing request, a |
| * Security request or a Pairing response before the wait interval expires |
| * PARAMS: addr - the address of the device |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smBanDeviceForTime(const struct bt_addr *addr) |
| { |
| struct smDevNode *n; |
| |
| if (!addr) |
| return; |
| |
| pthread_mutex_lock(&mDevLock); |
| |
| /* add the newly failed device in the banned device list */ |
| if (!(n = smBannedDevFindByAddr(addr))) { |
| n = smBannedDevAdd(addr); |
| logd("%s(): Add device "MACFMT" to banned list and start wait timer with "FMT64"u secs\n", |
| __func__, MACCONV(n->addr.addr), CNV64(n->waitInvl / 1000)); |
| } else { |
| /* if the failed device was previously added to the banned device list, increase the wait |
| * interval and update timers |
| */ |
| if (n->waitTimer) |
| timerCancel(n->waitTimer); |
| |
| if (n->waitInvl == SM_DEF_WAIT_INTVL) |
| n->waitInvl = SM_MIN_WAIT_INTVL; |
| else |
| n->waitInvl = n->waitInvl * SM_WAIT_INTVL_FACTOR > SM_MAX_WAIT_INTVL ? |
| SM_MAX_WAIT_INTVL : n->waitInvl * SM_WAIT_INTVL_FACTOR; |
| |
| n->waitTimer = timerSet(n->waitInvl, smWaitTimerCb, n->devId); |
| logd("%s(): Update device "MACFMT" and start wait timer with "FMT64"u secs\n", __func__, |
| MACCONV(n->addr.addr), CNV64(n->waitInvl / 1000)); |
| } |
| |
| pthread_mutex_unlock(&mDevLock); |
| } |
| |
| /* |
| * FUNCTION: smIsDevBanned |
| * USE: Start or update the wait interval timer to prevent from sending a Pairing request, a |
| * Security request or a Pairing response before the wait interval expires |
| * PARAMS: addr - the address of the device |
| * RETURN: is banned or not |
| * NOTES: |
| */ |
| static bool smIsDevBanned(const struct bt_addr *addr) |
| { |
| struct smDevNode *n; |
| |
| pthread_mutex_lock(&mDevLock); |
| n = smBannedDevFindByAddr(addr); |
| if (n) |
| logd("%s(): Device "MACFMT" is banned currently for "FMT64"u secs\n", __func__, |
| MACCONV(addr->addr), CNV64(n->waitInvl / 1000)); |
| pthread_mutex_unlock(&mDevLock); |
| |
| return n; |
| } |
| |
| /* |
| * FUNCTION: smSelPairAlg |
| * USE: Select the pairing algorithm base on IO capability, OOB data and |
| * Authentication request |
| * PARAMS: inst - the instance |
| * RETURN: pairing algorithm used |
| * NOTES: |
| */ |
| static uint8_t smSelPairAlg(const struct smInstance *inst) |
| { |
| if (!inst) |
| return SM_ALG_UNKNOWN; |
| |
| if ((mIoCap != HCI_DISP_CAP_DISP_ONLY && mIoCap != HCI_DISP_CAP_DISP_YES_NO && |
| mIoCap != HCI_DISP_CAP_KBD_ONLY && mIoCap != HCI_DISP_CAP_NONE && |
| mIoCap != HCI_DISP_CAP_KBD_DISP)|| |
| (inst->peerIoCap != HCI_DISP_CAP_DISP_ONLY && inst->peerIoCap != HCI_DISP_CAP_DISP_YES_NO && |
| inst->peerIoCap != HCI_DISP_CAP_KBD_ONLY && inst->peerIoCap != HCI_DISP_CAP_NONE && |
| inst->peerIoCap != HCI_DISP_CAP_KBD_DISP)) |
| return SM_ALG_UNKNOWN; |
| |
| /* check OOB support */ |
| if (inst->peerHasOob && mHasOob) |
| return SM_ALG_OOB; |
| |
| /* check MITM flag */ |
| /* TODO(mcchou): we use what ever requested by the peer device */ |
| if (!(inst->peerAuthReq & SM_AUTH_REQ_MITM_FLAG)) |
| return SM_ALG_JUST_WORK; |
| |
| /* check IO capability*/ |
| return inst->isInitiator ? mPairAlgs[inst->peerIoCap][mIoCap] : |
| mPairAlgs[mIoCap][inst->peerIoCap]; |
| } |
| |
| /* |
| * FUNCTION: smEncrChanged |
| * USE: Encryption changed - handle it |
| * PARAMS: inst - the instance |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smEncrChanged(struct smInstance *inst) |
| { |
| /* TODO(mcchou) */ |
| } |
| |
| /* |
| * FUNCTION: smTx |
| * USE: Send a packet to the peer |
| * PARAMS: inst - the instance |
| * pktTyp - packet type |
| * data - the data to send |
| * len - length of said data |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smTx(const struct smInstance *inst, uint8_t pktTyp, const void *data, uint8_t len) |
| { |
| sg tmpData = NULL; |
| struct smHdr hdr; |
| |
| utilSetLE8(&hdr.typ, pktTyp); |
| |
| tmpData = sgNewWithCopyData(data, len); |
| if (!tmpData) { |
| logw("%s(): Failed to alloc SG packet\n", __func__); |
| return false; |
| } |
| |
| if (!sgConcatFrontCopy(tmpData, &hdr, sizeof(hdr))) { |
| logw("%s(): Failed to copy SG header data\n", __func__); |
| goto tx_err; |
| } |
| |
| if (!sendQueueTx(mSmSendQ, inst->conn, tmpData)) { |
| logw("%s(): Failed to SG packet to sendQueue\n", __func__); |
| goto tx_err; |
| } |
| |
| logd("%s(): Packet successfully sent\n", __func__); |
| return true; |
| |
| tx_err: |
| sgFree(tmpData); |
| return false; |
| } |
| |
| /* |
| * FUNCTION: smParsePairReqResp |
| * USE: Parse a struct smPairReqResp into relevant instance variables |
| * PARAMS: inst - the instance |
| * pairReqResp - the struct |
| * RETURN: true if all values were read & found valid |
| * NOTES: |
| */ |
| static bool smParsePairReqResp(struct smInstance *inst, const struct smPairReqResp *pairReqResp) |
| { |
| uint8_t tmp, initKeyDistr, rspKeyDistr; |
| tmp = utilGetLE8(&pairReqResp->ioCap); |
| if (tmp != HCI_DISP_CAP_DISP_ONLY && tmp != HCI_DISP_CAP_DISP_YES_NO && |
| tmp != HCI_DISP_CAP_KBD_ONLY && tmp != HCI_DISP_CAP_NONE && |
| tmp != HCI_DISP_CAP_KBD_DISP) { |
| logd("Invalid io caps RXed 0x%02X\n", tmp); |
| return false; |
| } |
| inst->peerIoCap = tmp; |
| |
| tmp = utilGetLE8(&pairReqResp->oobDataFlag); |
| if (tmp != 0 && tmp != 1) { |
| logd("Invalid oob flag RXed 0x%02X\n", tmp); |
| return false; |
| } |
| inst->peerHasOob = !!tmp; |
| |
| tmp = utilGetLE8(&pairReqResp->authReq); |
| if ((tmp & SM_AUTH_REQ_BOND_MASK) != SM_AUTH_REQ_BOND_NO && |
| (tmp & SM_AUTH_REQ_BOND_MASK) != SM_AUTH_REQ_BOND_BOND) { |
| logd("Invalid authReq RXed 0x%02X\n", tmp); |
| return false; |
| } |
| inst->peerAuthReq = tmp; |
| |
| tmp = utilGetLE8(&pairReqResp->maxKeySz); |
| if (tmp < SM_MIN_KEY_LEN || tmp > SM_MAX_KEY_LEN) { |
| logd("Invalid maxKeySize RXed 0x%02X\n", tmp); |
| return false; |
| } |
| inst->peerMaxKeySz = tmp; |
| |
| tmp = utilGetLE8(&pairReqResp->initiatorKeyDistr); |
| if (tmp &~ (SM_KEY_DISTR_LTK | SM_KEY_DISTR_IRK | SM_KEY_DISTR_CSRK)) { |
| logd("Invalid keyDistr.i RXed 0x%02X\n", tmp); |
| return false; |
| } |
| initKeyDistr = tmp; |
| |
| tmp = utilGetLE8(&pairReqResp->responderKeyDistr); |
| if (tmp &~ (SM_KEY_DISTR_LTK | SM_KEY_DISTR_IRK | SM_KEY_DISTR_CSRK)) { |
| logd("Invalid keyDistr.r RXed 0x%02X\n", tmp); |
| return false; |
| } |
| rspKeyDistr = tmp; |
| |
| if (inst->isInitiator) { /* must be a response. accept as many as given */ |
| /* TODO(mcchou): do not send any keys we did not already commit to send inst->myKeyDistr &= initKeyDistr; */ |
| inst->myKeyDistr = initKeyDistr; |
| inst->peerKeyDistr = rspKeyDistr; |
| } else { /* must be a request - agree to send all keys they want, accept whatever was given */ |
| inst->myKeyDistr = rspKeyDistr; |
| inst->peerKeyDistr = initKeyDistr; |
| } |
| |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smReverseBytes |
| * USE: Reverse the byte stream field of a pairing struct and store bytes |
| * in MSB first order |
| * PARAMS: out - the output byte array |
| * outLen - the length of out |
| * in - the input byte array |
| * InLen - the length of in |
| * RETURN: success |
| * NOTES: Used for Pairing Confirm CMD, Pairing Random CMD |
| */ |
| static bool smReverseBytes(uint8_t *out, int outLen, const uint8_t *in, int inLen) |
| { |
| int i; |
| |
| if (outLen <= 0 || inLen <= 0 || outLen != inLen) |
| return false; |
| |
| for (i = 0; i < inLen; ++i) |
| out[i] = utilGetLE8(&in[inLen - i - 1]); |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smSendPairReq |
| * USE: Send pairing request |
| * PARAMS: inst - the instance of the initiator |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smSendPairReq(struct smInstance *inst) |
| { |
| struct smPairReqResp req; |
| |
| inst->isInitiator = true; |
| |
| utilSetLE8(&req.ioCap, mIoCap); |
| /* TODO(mcchou): this needs to be changed accordingly for OOB support */ |
| utilSetLE8(&req.oobDataFlag, mHasOob); |
| utilSetLE8(&req.authReq, inst->myAuthReq); |
| utilSetLE8(&req.maxKeySz, inst->myMaxKeySz); |
| utilSetLE8(&req.initiatorKeyDistr, inst->myKeyDistr); |
| /* TODO(mcchou): this needs to be changed */ |
| utilSetLE8(&req.responderKeyDistr, inst->myKeyDistr); |
| |
| if (!smTx(inst, SM_PAIRING_REQ, &req, sizeof(req))) { |
| logw("%s(): Failed to send pairing request command\n", __func__); |
| return false; |
| } |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smSendPairResp |
| * USE: Send pairing response |
| * PARAMS: inst - the instance of the initiator |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smSendPairResp(const struct smInstance *inst) |
| { |
| struct smPairReqResp resp; |
| |
| if (inst->isInitiator) { |
| logw("%s(): Unexpected to send pairing response\n", __func__); |
| return false; |
| } |
| |
| utilSetLE8(&resp.ioCap, mIoCap); |
| /* TODO(mcchou): this needs to be changed accordingly for OOB support */ |
| utilSetLE8(&resp.oobDataFlag, mHasOob); |
| utilSetLE8(&resp.authReq, inst->myAuthReq); |
| utilSetLE8(&resp.maxKeySz, inst->myMaxKeySz); |
| utilSetLE8(&resp.initiatorKeyDistr, inst->peerKeyDistr); /* accept whatever they promised us */ |
| utilSetLE8(&resp.responderKeyDistr, inst->myKeyDistr); /* give up whatever they asked for */ |
| |
| if (!smTx(inst, SM_PAIRING_RSP, &resp, sizeof(resp))) { |
| logw("%s(): Failed to send pairing response command\n", __func__); |
| return false; |
| } |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smSendPairConf |
| * USE: Send pairing confirm value |
| * PARAMS: inst - the instance of the initiator |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smSendPairConf(const struct smInstance *inst) |
| { |
| uint16_t i, confSz; |
| struct smPairConf conf; |
| |
| for (i = 0, confSz = sizeof(inst->myConfVal.confirmVal); i < confSz ; ++i) |
| utilSetLE8(&conf.confirmVal[i], inst->myConfVal.confirmVal[confSz - i - 1]); |
| |
| if (!smTx(inst, SM_PAIRING_CONF, &conf, sizeof(conf))) { |
| logw("%s(): Failed to send pairing confirm command\n", __func__); |
| return false; |
| } |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smSendPairRand |
| * USE: Send pairing Random number |
| * PARAMS: inst - the instance of the initiator |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smSendPairRand(const struct smInstance *inst) |
| { |
| uint16_t i, randSz; |
| struct smPairRand rand; |
| |
| for (i = 0, randSz = sizeof(inst->myRandNum.rand); i < randSz ; ++i) |
| utilSetLE8(&rand.rand[i], inst->myRandNum.rand[randSz - i - 1]); |
| |
| if (!smTx(inst, SM_PAIRING_RAND, &rand, sizeof(rand))) { |
| logw("%s(): Failed to send pairing random command\n", __func__); |
| return false; |
| } |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smSendPairFail |
| * USE: Send a pairing error to the peer |
| * PARAMS: inst - the instance |
| * reason - the error reason |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smSendPairFail(const struct smInstance *inst, uint8_t reason) |
| { |
| struct smPairFailed fail; |
| |
| smBanDeviceForTime(&inst->peerAddr); |
| utilSetLE8(&fail.reason, reason); |
| |
| return smTx(inst, SM_PAIRING_FAIL, &fail, sizeof(fail)); |
| } |
| |
| /* |
| * FUNCTION: smTransitPhase |
| * USE: Log and transit the phase of pairing process |
| * PARAMS: inst - the instance |
| * phase - the phase to transit to |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smTransitPhase(struct smInstance *inst, uint8_t phase) { |
| if (phase != SM_PHASE_START && phase != SM_PHASE_REQ_SENT && |
| phase != SM_PHASE_REQ_RESP && phase != SM_PHASE_CONF_SENT && |
| phase != SM_PHASE_CONF_RESP && phase != SM_PHASE_RAND_SENT && |
| phase != SM_PHASE_RAND_RESP) { |
| logd("Invalid phase to transit, phase 0x%02X\n", phase); |
| return; |
| } |
| if (inst->phase == phase) { |
| logd("Phase transition skipped, phase 0x%02X\n", phase); |
| return; |
| } |
| |
| logd("Transit from 0x%02X to 0x%02X\n", inst->phase, phase); |
| inst->phase = phase; |
| } |
| |
| /* |
| * FUNCTION: smRx |
| * USE: Data arrived - handle it |
| * PARAMS: inst - the instance |
| * packet - the data that arrived |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smRx(struct smInstance *inst, sg packet) |
| { |
| struct smHdr hdr; |
| struct smPairReqResp pairReqResp; |
| struct smPairConf pairConf; |
| struct smPairRand pairRand; |
| struct smPairFailed pairFailed; |
| uint8_t typ, tmp; |
| |
| if (!sgSerializeCutFront(packet, &hdr, sizeof(hdr))) { |
| logw("Incoming SM packet header extraction failed\n"); |
| sgFree(packet); |
| return; |
| } |
| |
| typ = utilGetLE8(&hdr.typ); |
| switch (typ) { |
| case SM_PAIRING_REQ: |
| if (!sgSerializeCutFront(packet, &pairReqResp, sizeof(pairReqResp))) { |
| logw("Incoming SM packet data extraction failed\n"); |
| break; |
| } |
| if (sgLength(packet)) { |
| logw("Residual data in packet: %u\n", sgLength(packet)); |
| smSendPairFail(inst, SM_ERR_INVALID_PARAMS); |
| break; |
| } |
| if (inst->phase != SM_PHASE_START) { |
| logd("Got pairing req in phase %u\n", inst->phase); |
| break; |
| } |
| |
| inst->isInitiator = false; |
| if (!smParsePairReqResp(inst, &pairReqResp)) { |
| smSendPairFail(inst, SM_ERR_INVALID_PARAMS); |
| break; |
| } |
| |
| if (!smGenRandNum(inst)) |
| break; |
| if (!smGenTK(inst)) |
| break; |
| if (!smGenConfVal(&inst->myConfVal, inst, false)) |
| break; |
| |
| if (!smSendPairResp(inst)) |
| break; |
| smTransitPhase(inst, SM_PHASE_REQ_RESP); |
| |
| goto done; |
| |
| case SM_PAIRING_RSP: |
| if (!sgSerializeCutFront(packet, &pairReqResp, sizeof(pairReqResp))) { |
| logw("Incoming SM packet data extraction failed\n"); |
| break; |
| } |
| if (sgLength(packet)) { |
| logw("Residual data in packet: %u\n", sgLength(packet)); |
| smSendPairFail(inst, SM_ERR_INVALID_PARAMS); |
| break; |
| } |
| if (inst->phase != SM_PHASE_REQ_SENT|| !inst->isInitiator) { |
| logd("Got pairing resp in phase %u when we %s the initiator\n", inst->phase, |
| inst->isInitiator ? "are" : "are not"); |
| break; |
| } |
| |
| if (!smParsePairReqResp(inst, &pairReqResp)) { |
| smSendPairFail(inst, SM_ERR_INVALID_PARAMS); |
| break; |
| } |
| |
| if (!smGenRandNum(inst)) |
| break; |
| if (!smGenTK(inst)) |
| break; |
| if (!smGenConfVal(&inst->myConfVal, inst, false)) |
| break; |
| |
| if (!smSendPairConf(inst)) |
| break; |
| smTransitPhase(inst, SM_PHASE_CONF_SENT); |
| |
| goto done; |
| |
| case SM_PAIRING_CONF: |
| if (!sgSerializeCutFront(packet, &pairConf, sizeof(pairConf))) { |
| logw("Incoming SM packet data extraction failed\n"); |
| break; |
| } |
| if (sgLength(packet)) { |
| logw("Residual data in packet: %u\n", sgLength(packet)); |
| smSendPairFail(inst, SM_ERR_INVALID_PARAMS); |
| break; |
| } |
| if ((inst->isInitiator && inst->phase != SM_PHASE_CONF_SENT) || |
| (!inst->isInitiator && inst->phase != SM_PHASE_REQ_RESP)) { |
| logd("Got pairing conf in phase %u when we %s the initiator \n", inst->phase, |
| inst->isInitiator ? "are" : "are not"); |
| break; |
| } |
| |
| if (!smReverseBytes(inst->peerConfVal.confirmVal, sizeof(inst->peerConfVal.confirmVal), |
| pairConf.confirmVal, sizeof(pairConf.confirmVal))) |
| break; |
| |
| if (inst->isInitiator) { |
| if (!smSendPairRand(inst)) |
| break; |
| smTransitPhase(inst, SM_PHASE_RAND_SENT); |
| } else { |
| if (!smSendPairConf(inst)) |
| break; |
| smTransitPhase(inst, SM_PHASE_CONF_RESP); |
| } |
| |
| goto done; |
| |
| case SM_PAIRING_RAND: |
| if (!sgSerializeCutFront(packet, &pairRand, sizeof(pairRand))) { |
| logw("Incoming SM packet data extraction failed\n"); |
| break; |
| } |
| if (sgLength(packet)) { |
| logw("Residual data in packet: %u\n", sgLength(packet)); |
| smSendPairFail(inst, SM_ERR_INVALID_PARAMS); |
| break; |
| } |
| if ((inst->isInitiator && inst->phase != SM_PHASE_RAND_SENT) || |
| (!inst->isInitiator && inst->phase != SM_PHASE_CONF_RESP)) { |
| logd("Got pairing rand in phase %u when we %s the initiator \n", inst->phase, |
| inst->isInitiator ? "are" : "are not"); |
| break; |
| } |
| |
| if (!smReverseBytes(inst->peerRandNum.rand, sizeof(inst->peerRandNum.rand), |
| pairRand.rand, sizeof(pairRand.rand))) |
| break; |
| |
| /* check if the peer confirm value generated from the random value matches */ |
| smGenConfVal(&pairConf, inst, true); |
| if (memcmp(pairConf.confirmVal, inst->peerConfVal.confirmVal, |
| sizeof(pairConf.confirmVal)) != 0) { |
| smSendPairFail(inst, SM_ERR_CONF_VAL_FAILED); |
| break; |
| } |
| if (!inst->isInitiator && !smSendPairRand(inst)) |
| break; |
| smTransitPhase(inst, SM_PHASE_RAND_RESP); |
| |
| if (!smGenSTK(inst)) |
| break; |
| |
| /* TODO(mcchou): if we are the initiator, encrypt the link using the STK */ |
| |
| goto done; |
| |
| case SM_PAIRING_FAIL: |
| if (!sgSerializeCutFront(packet, &pairFailed, sizeof(pairFailed))) { |
| logw("Incoming SM packet data extraction failed\n"); |
| break; |
| } |
| if (sgLength(packet)) { |
| logw("Residual data in packet: %u\n", sgLength(packet)); |
| smSendPairFail(inst, SM_ERR_INVALID_PARAMS); |
| break; |
| } |
| |
| smTransitPhase(inst, SM_PHASE_START); |
| smBanDeviceForTime(&inst->peerAddr); |
| |
| goto done; |
| |
| case SM_ENCR_INFO: |
| case SM_MASTER_INFO: |
| case SM_IDENTITY_INFO: |
| case SM_IDENTITY_ADDR_INFO: |
| case SM_SIGNING_INFO: |
| case SM_SECURITY_REQUEST: |
| logw("Unhandled packet type 0x%02X in SM. Dropping\n", typ); |
| goto done; |
| default: |
| logw("Unxpected packet type 0x%02X in SM. Dropping\n", typ); |
| break; |
| } |
| |
| smTransitPhase(inst, SM_PHASE_START); |
| done: |
| sgFree(packet); |
| return; |
| } |
| |
| /* |
| * FUNCTION: smInstFindByConn |
| * USE: Find the instance node by the connection ID |
| * PARAMS: conn - the connection ID |
| * RETURN: the instance if matched; NULL otherwise |
| * NOTES: call with mInstLock held |
| */ |
| static struct smInstance* smInstFindByConn(l2c_handle_t conn) |
| { |
| struct smInstance *inst = mActInstList; |
| |
| if (!conn) |
| return NULL; |
| |
| while(inst) { |
| if (inst->conn == conn) |
| return inst; |
| inst = inst->next; |
| } |
| return NULL; |
| } |
| |
| /* |
| * FUNCTION: smStallTimerCb |
| * USE: Called when the stallTimer of an instance is fired to terminate a stall pairing session |
| * PARAMS: timerId - an unique ID of a timer |
| * conn - a connection handle |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smStallTimerCb(uniq_t timerId, uint64_t conn) |
| { |
| struct smInstance *inst; |
| |
| pthread_mutex_lock(&mInstLock); |
| |
| inst = smInstFindByConn(conn); |
| if (!inst) { |
| pthread_mutex_unlock(&mInstLock); |
| return; |
| } |
| |
| inst->stallTimer = 0; |
| logd("%s(): Pairing with device "MACFMT" is stalled\n", __func__, |
| MACCONV(inst->peerAddr.addr)); |
| |
| smBanDeviceForTime(&inst->peerAddr); |
| |
| pthread_mutex_unlock(&mInstLock); |
| |
| l2cApiDisconnect(conn); |
| } |
| |
| /* |
| * FUNCTION: smInstFree |
| * USE: Free a per-connection instance struct |
| * PARAMS: inst - the instance |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smInstFree(struct smInstance *inst) |
| { |
| if (inst->stallTimer) |
| timerCancel(inst->stallTimer); |
| free(inst); |
| } |
| |
| /* |
| * FUNCTION: smInstDeinit |
| * USE: Delete an instance from the active instance list and free it |
| * PARAMS: inst - the instance |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smInstDeinit(struct smInstance* inst) |
| { |
| pthread_mutex_lock(&mInstLock); |
| if (!inst) |
| return; |
| |
| if (inst->next) |
| inst->next->prev = inst->prev; |
| if (inst->prev) |
| inst->prev->next = inst->next; |
| else |
| mActInstList = inst->next; |
| |
| smInstFree(inst); |
| pthread_mutex_unlock(&mInstLock); |
| } |
| |
| /* |
| * FUNCTION: smInstInit |
| * USE: Set some default values for pairing phase and repeated attempt field of an instance |
| * PARAMS: inst - the instance |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smInstInit(struct smInstance *inst) |
| { |
| pthread_mutex_lock(&mInstLock); |
| |
| inst->prev = NULL; |
| inst->next = mActInstList; |
| if (mActInstList) |
| mActInstList->prev = inst; |
| mActInstList = inst; |
| |
| inst->phase = SM_PHASE_START; |
| /* TODO(mcchou): the stall timer needs to be canceled when the pairing finishes correctly */ |
| inst->stallTimer = timerSet(SM_STALL_INTVL, smStallTimerCb, inst->conn); |
| |
| pthread_mutex_unlock(&mInstLock); |
| } |
| |
| /* |
| * FUNCTION: smFixedChState |
| * USE: Connection event happened |
| * PARAMS: userData - unused |
| * instance - per-connection instance allocated by smFixedChAlloc() |
| * evt - what happened |
| * data - the pertinent data |
| * len - length of said data |
| * RETURN: SVC_ALLOC_* |
| * NOTES: |
| */ |
| static void smFixedChState(void *userData, void *instance, uint8_t evt, const void *data, |
| uint32_t len) |
| { |
| struct smInstance *inst = (struct smInstance*)instance; |
| l2c_handle_t conn; |
| sg s; |
| |
| switch (evt) { |
| case L2C_STATE_OPEN: |
| if (len != sizeof(l2c_handle_t)) { |
| loge("invalid length for open event\n"); |
| break; |
| } |
| conn = *(l2c_handle_t*)data; |
| /* when we support outbound connections, this code will need to evolve */ |
| if (inst->conn != conn) |
| loge("Handle change!!!\n"); |
| |
| smInstInit(inst); |
| |
| break; |
| |
| case L2C_STATE_ENCR: |
| if (len != sizeof(struct l2cEncrState)) { |
| loge("invalid length for encr event\n"); |
| break; |
| } |
| smEncrChanged(inst); |
| break; |
| |
| case L2C_STATE_RX: |
| if (len != sizeof(sg)) { |
| loge("invalid length for RX event\n"); |
| break; |
| } |
| s = *(sg*)data; |
| smRx(inst, s); |
| break; |
| |
| case L2C_STATE_CLOSED: |
| smInstDeinit(inst); |
| break; |
| default: |
| logd("unknown L2C event %u\n", evt); |
| break; |
| } |
| } |
| |
| /* |
| * FUNCTION: smFixedChAlloc |
| * USE: Connection request: if accepted, alloc a per-connection instance of the SM connection |
| * structure |
| * PARAMS: userData - unused |
| * conn - l2c conn handle |
| * instanceP - we store instance here if we allocate one |
| * RETURN: SVC_ALLOC_* |
| * NOTES: |
| */ |
| static uint8_t smFixedChAlloc(void *userData, l2c_handle_t conn, void **instanceP) |
| { |
| struct smInstance *inst; |
| struct bt_addr peerAddr; |
| struct bt_addr myAddr; |
| |
| if (!l2cApiGetBtAddr(conn, &peerAddr)) { |
| loge("Failed to get peer address\n"); |
| return SVC_ALLOC_FAIL_OTHER; |
| } |
| |
| if(!l2cApiGetSelfBtAddr(conn, &myAddr)) { |
| logd("Failed to get local address\n"); |
| return SVC_ALLOC_FAIL_OTHER; |
| } |
| |
| if (!BT_ADDR_IS_LE(peerAddr)) { |
| logd("Refusing SM connection for EDR\n"); |
| return SVC_ALLOC_FAIL_OTHER; |
| } |
| |
| if (smIsDevBanned(&peerAddr)) { |
| smBanDeviceForTime(&peerAddr); |
| return SVC_ALLOC_FAIL_OTHER; |
| } |
| |
| inst = (struct smInstance*)calloc(1, sizeof(struct smInstance)); |
| if (!inst) |
| return SVC_ALLOC_FAIL_OTHER; |
| |
| memcpy(&inst->peerAddr, &peerAddr, sizeof(struct bt_addr)); |
| memcpy(&inst->myAddr, &myAddr, sizeof(struct bt_addr)); |
| |
| /* TODO(mcchou): default settings. we need to provide ATT a way to set authentication requirement for a certain instance */ |
| inst->myAuthReq = SM_AUTH_REQ_BOND_BOND | SM_AUTH_REQ_MITM_FLAG; |
| inst->myMaxKeySz = SM_MAX_KEY_LEN; |
| inst->myKeyDistr = SM_KEY_DISTR_LTK | SM_KEY_DISTR_IRK | SM_KEY_DISTR_CSRK; |
| |
| inst->conn = conn; |
| *instanceP = inst; |
| |
| logd("%s() sm channel assigned\n", __func__); |
| |
| return SVC_ALLOC_SUCCESS; |
| } |
| |
| /* |
| * FUNCTION: smInit |
| * USE: Init the security manager |
| * PARAMS: NONE |
| * RETURN: success |
| * NOTES: |
| */ |
| bool smInit(uint8_t ioCapability) |
| { |
| static const struct l2cServiceFixedChDescriptor descr = { |
| .serviceFixedChAlloc = smFixedChAlloc, |
| .serviceFixedChStateCbk = smFixedChState, |
| }; |
| |
| if (ioCapability != HCI_DISP_CAP_DISP_ONLY && ioCapability != HCI_DISP_CAP_DISP_YES_NO && |
| ioCapability != HCI_DISP_CAP_KBD_ONLY && ioCapability != HCI_DISP_CAP_NONE && |
| ioCapability != HCI_DISP_CAP_KBD_DISP) { |
| return false; |
| } |
| mIoCap = ioCapability; |
| |
| /* TODO(mcchou): this needs to be changed accordingly for the OOB support */ |
| mHasOob = false; |
| if (!(mSmSendQ = sendQueueAlloc(MAX_PACKETS_SM_SEND_QUEUE))) { |
| logw("%s(): Error allocating SM sendQ.\n", __func__); |
| return false; |
| } |
| |
| if(!l2cApiServiceFixedChRegister(L2C_FIXED_CH_NUM_SM, &descr)) { |
| logw("%s(): Error registering L2CAP service.\n", __func__); |
| sendQueueFree(mSmSendQ); |
| return false; |
| } |
| |
| logd("%s() smInit finished correctly\n", __func__); |
| |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smDeinit |
| * USE: Deinit the security manager |
| * PARAMS: NONE |
| * RETURN: NONE |
| * NOTES: |
| */ |
| void smDeinit(void) |
| { |
| smBannedDevFreeAll(); |
| sendQueueFree(mSmSendQ); |
| l2cApiServiceFixedChUnregister(L2C_FIXED_CH_NUM_SM, NULL, NULL); |
| } |
| |
| /* |
| * FUNCTION: smCmacDo |
| * USE: Perform the CMAC calculation |
| * PARAMS: dst - where the store the result |
| * macLen - how long of a digest do we want (in bytes) |
| * m - the message to digest |
| * k - the key to use |
| * k1 - subkey 1 (from smCmacPrepare) |
| * k2 - subkey 2 (from smCmacPrepare) |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smCmacDo(uint8_t *dst, uint8_t macLen, sg m, const uint8_t *k, const uint8_t *k1, |
| const uint8_t *k2) |
| { |
| uint32_t len = sgLength(m), pos = 0; |
| uint32_t i, nblocks = len ? (len + SM_BLOCK_LEN - 1) / SM_BLOCK_LEN : 1; |
| uint8_t tmp1[SM_BLOCK_LEN] = {0,}, tmp2[SM_BLOCK_LEN], j, *in = tmp1, *out = tmp2, *swap; |
| |
| for (i = 0; i < nblocks; i++) { |
| for(j = 0; j < len && j < SM_BLOCK_LEN; j++) { |
| uint8_t byte; |
| |
| sgSerialize(m, pos++, sizeof(uint8_t),&byte); |
| in[j] ^= byte; |
| } |
| len -= j; |
| if (!len) { |
| if (j == SM_BLOCK_LEN) { |
| for(j = 0; j < SM_BLOCK_LEN; j++) |
| in[j] ^= *k1++; |
| } else { |
| in[j] ^= 0x80; |
| for(j = 0; j < SM_BLOCK_LEN; j++) |
| in[j] ^= *k2++; |
| } |
| } |
| smEncrypt(out, in, k); |
| swap = in; |
| in = out; |
| out = swap; |
| } |
| while (macLen--) |
| *dst++ = *in++; |
| } |
| |
| /* |
| * FUNCTION: smCmacPrepare |
| * USE: Perform the pre-calculation of K1 & K2 for the CMAC |
| * PARAMS: k1 - where to store k1 |
| * k2 - where to store k2 |
| * k - the k input value |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static void smCmacPrepare(uint8_t *k1, uint8_t *k2, const uint8_t *k) |
| { |
| uint8_t tmp[SM_BLOCK_LEN] = {0,}, *out = k1, i, j; |
| |
| smEncrypt(k1, tmp, k); |
| for (i = 0; i < 2; i++) { |
| bool shiftOut; |
| shiftOut = !!(k1[0] & 0x80); |
| for (j = 0; j < 15; j++) |
| out[j] = (k1[j] << 1) | (k1[j + 1] >> 7); |
| out[15] = k1[15] << 1; |
| if (shiftOut) |
| out[15] ^= 0x87; |
| out = k2; |
| } |
| } |
| |
| /* |
| * FUNCTION: smSignatureCalc |
| * USE: Perform a CMAC calculation in its entirety |
| * PARAMS: data - the data to checksum |
| * len - length of said data |
| * key - the key |
| * sig - sig gets stored here |
| * RETURN: NONE |
| * NOTES: |
| */ |
| void smSignatureCalc(sg m, const uint8_t *key, uint8_t *sig) |
| { |
| uint8_t k1[SM_BLOCK_LEN], k2[SM_BLOCK_LEN]; |
| |
| smCmacPrepare(k1, k2, key); |
| smCmacDo(sig, SM_SIG_LEN, m, key, k1, k2); |
| } |
| |
| /* |
| * FUNCTION: smCalcKey |
| * USE: Perform the calculation of a key |
| * PARAMS: out - store the result here |
| * k - the k value as per spec |
| * p1 - the p1 value as per spec |
| * p2 - the p2 calue as per spec |
| * RETURN: NONE |
| * NOTES: The SM docs call this the s1() function |
| */ |
| static_or_test void smCalcKey(uint8_t *out, const uint8_t *k, const uint8_t *r1, const uint8_t *r2) |
| { |
| uint8_t t[SM_BLOCK_LEN]; |
| uint8_t i; |
| |
| for (i = 0; i < 8; i++) { |
| t[i + 0] = r1[i + 8]; |
| t[i + 8] = r2[i + 8]; |
| } |
| smEncrypt(out, t, k); |
| } |
| |
| /* |
| * FUNCTION: smCalcConfVal |
| * USE: Perform the calculation of the confirmation value |
| * PARAMS: out - store the result here |
| * k - the k value as per spec |
| * r - the r value as per spec |
| * pres - the pres value as per spec, only bottom 56 bit used |
| * preq - the pres value as per spec, only bottom 56 bit used |
| * iat - the iat value as per spec |
| * ia - the ia value as per spec, only bottom 48 bits used |
| * rat - the rat value as per spec |
| * ra - the ra value as per spec, only bottom 48 bits used |
| * RETURN: NONE |
| * NOTES: The SM docs call this the c1() function |
| */ |
| static_or_test void smCalcConfVal(uint8_t* out, const uint8_t *k, const uint8_t *r, uint64_t pres, |
| uint64_t preq, bool iat, uint64_t ia, bool rat, uint64_t ra) |
| { |
| uint8_t p1[SM_BLOCK_LEN]; |
| uint8_t p2[SM_BLOCK_LEN] = {0,}; |
| uint8_t i; |
| |
| /* create p1 */ |
| for (i = 0; i < 7; i++) { |
| p1[6 - i] = pres; |
| p1[13 - i] = preq; |
| pres >>= 8; |
| preq >>= 8; |
| } |
| p1[14] = rat ? 1 : 0; |
| p1[15] = iat ? 1 : 0; |
| |
| /* create p2 */ |
| for (i = 0; i < 6; i++) { |
| p2[9 - i] = ia; |
| p2[15 - i] = ra; |
| ia >>= 8; |
| ra >>= 8; |
| } |
| |
| /* p1 ^= r */ |
| for (i = 0; i < SM_BLOCK_LEN; i++) |
| p1[i] ^= r[i]; |
| |
| /* out = e(k, p1) */ |
| smEncrypt(out, p1, k); |
| |
| /* p2 ^= out */ |
| for (i = 0; i < SM_BLOCK_LEN; i++) |
| p2[i] ^= out[i]; |
| |
| /* out = e(k, p2) */ |
| smEncrypt(out, p2, k); |
| } |
| |
| /* |
| * FUNCTION: smPrepPreqPrsp |
| * USE: Prepare the pairing request command or the pairing response |
| * command by reconstructing fields into a uint64_t value |
| * PARAS: cmd - output |
| * reqRsp - command type |
| * ioCap - IO capability |
| * hasOob - OOB data flag |
| * authReq - security properties |
| * maxKeySz - maximum key size |
| * initKeyDistr - initiator key distribution |
| * rspKeyDistr - responder key distribution |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smPrepPreqPrsp( |
| uint64_t *cmd, uint8_t reqRsp, uint8_t ioCap, bool hasOob, uint8_t authReq, uint8_t maxKeySz, |
| uint8_t initKeyDistr, uint8_t rspKeyDistr) |
| { |
| uint8_t oob = hasOob; |
| |
| if (!cmd) |
| return false; |
| |
| if (reqRsp != SM_PAIRING_REQ && reqRsp != SM_PAIRING_RSP) |
| return false; |
| |
| *cmd = utilGetBE8(&rspKeyDistr); |
| *cmd = *cmd << 8 | utilGetBE8(&initKeyDistr); |
| *cmd = *cmd << 8 | utilGetBE8(&maxKeySz); |
| *cmd = *cmd << 8 | utilGetBE8(&authReq); |
| *cmd = *cmd << 8 | utilGetBE8(&oob); |
| *cmd = *cmd << 8 | utilGetBE8(&ioCap); |
| *cmd = *cmd << 8 | reqRsp; |
| |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smPrepInitRspAddr |
| * USE: Prepare the initiator device address or the responding device |
| * address by reconstructing a struct bt_addr into an uint64_t value |
| * PARAS: a - output uint64_t |
| * at - output address types (public or random) |
| * addr - address |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smPrepInitRspAddr(uint64_t *a, bool *at, const struct bt_addr *addr) |
| { |
| int i; |
| uint8_t type; |
| |
| if (!addr) |
| return false; |
| |
| *at = addr->type != BT_ADDR_TYPE_EDR && addr->type != BT_ADDR_TYPE_LE_PUBLIC; |
| for (i = sizeof(addr->addr) - 1, *a = 0; i >= 0; --i) |
| *a = (*a << 8) | addr->addr[i]; /* addr is stored in [0]->[5] : LSO -> MSO */ |
| |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smGenSTK |
| * USE: Generate a 128-bit Short Term Key, mask it with the negotiated key size and store it |
| * in the given instance |
| * PARAS: inst - instance |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smGenSTK(struct smInstance *inst) |
| { |
| uint8_t i, maskLen; |
| |
| if (!inst) { |
| logw("%s(): Invalid instance\n", __func__); |
| return false; |
| } |
| |
| smCalcKey((uint8_t *)inst->stk.key, (uint8_t *)inst->tk.key, |
| inst->isInitiator ? inst->peerRandNum.rand : inst->myRandNum.rand, |
| inst->isInitiator ? inst->myRandNum.rand : inst->peerRandNum.rand); |
| |
| maskLen = SM_MAX_KEY_LEN - |
| (inst->myMaxKeySz > inst->peerMaxKeySz ? inst->peerMaxKeySz : inst->myMaxKeySz); |
| for (i = 0; i < maskLen; ++i) |
| inst->stk.key[i] = 0x00; |
| |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smGenTK |
| * USE: Generate a 128-bit Temporary Key and store it in the given instance |
| * PARAS: inst - instance |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smGenTK(struct smInstance *inst) |
| { |
| uint8_t pairAlg; |
| |
| if ((pairAlg = smSelPairAlg(inst)) == SM_ALG_UNKNOWN) |
| return false; |
| |
| logd("Pairing method chosen: 0x%02X\n", pairAlg); |
| |
| /* generate TK */ |
| switch(pairAlg) { |
| case SM_ALG_JUST_WORK: |
| memset(inst->tk.key, 0, sizeof(inst->tk.key)); |
| break; |
| case SM_ALG_PASS_KEY: /* TODO(mcchou): retrieve passkey from user */ |
| case SM_ALG_OOB: /* TODO(mcchou): retrieve OOB data from OOB source */ |
| logw("%s(): Not implemented\n", __func__); |
| return false; |
| default: |
| logw("%s(): Unknown pairing algorithm %d", __func__, pairAlg); |
| return false; |
| } |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smGenConfVal |
| * USE: Generate a 128-bit random number and store it in the given instance. This should be |
| * called after calling smGenTK. |
| * PARAS: rand - the output random number |
| * inst - instance |
| * check - indicate whether this is confirm value check or not, if true, peer random |
| * value will be used as the input of confirm value calculation; otherwise the |
| * local random value will be used. |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smGenConfVal(struct smPairConf *conf, const struct smInstance *inst, bool check) |
| { |
| uint64_t pReqCmd = 0, pRspCmd = 0, ia = 0, ra = 0; |
| bool iat = false, rat = false; |
| int i; |
| |
| if (!inst) { |
| logw("%s(): Invalid instance\n", __func__); |
| return false; |
| } |
| |
| /* prepare params for calculation of confirm value */ |
| if (inst->isInitiator) { |
| if (!smPrepPreqPrsp(&pReqCmd, SM_PAIRING_REQ, mIoCap, mHasOob, inst->myAuthReq, |
| inst->myMaxKeySz, inst->peerKeyDistr, inst->myKeyDistr) || |
| !smPrepPreqPrsp(&pRspCmd, SM_PAIRING_RSP, inst->peerIoCap, inst->peerHasOob, |
| inst->peerAuthReq, inst->peerMaxKeySz, inst->peerKeyDistr, |
| inst->myKeyDistr) || |
| !smPrepInitRspAddr(&ia, &iat, &inst->myAddr) || |
| !smPrepInitRspAddr(&ra, &rat, &inst->peerAddr)) |
| goto fail; |
| } else { |
| if (!smPrepPreqPrsp(&pReqCmd, SM_PAIRING_REQ, inst->peerIoCap, inst->peerHasOob, |
| inst->peerAuthReq, inst->peerMaxKeySz, inst->myKeyDistr, |
| inst->peerKeyDistr) || |
| !smPrepPreqPrsp(&pRspCmd, SM_PAIRING_RSP, mIoCap, mHasOob, inst->myAuthReq, |
| inst->myMaxKeySz, inst->myKeyDistr, inst->peerKeyDistr) || |
| !smPrepInitRspAddr(&ia, &iat, &inst->peerAddr) || |
| !smPrepInitRspAddr(&ra, &rat, &inst->myAddr)) |
| goto fail; |
| } |
| |
| smCalcConfVal(conf->confirmVal, (uint8_t *)inst->tk.key, |
| check ? inst->peerRandNum.rand : inst->myRandNum.rand, |
| pRspCmd, pReqCmd, iat, ia, rat, ra); |
| |
| return true; |
| |
| fail: |
| logw("%s(): Preparation error\n", __func__); |
| return false; |
| } |
| |
| /* |
| * FUNCTION: smGenRandNum |
| * USE: Generate a 128-bit random number and store it in the given instance |
| * PARAS: inst - instance |
| * RETURN: success |
| * NOTES: |
| */ |
| static bool smGenRandNum(struct smInstance *inst) |
| { |
| int r = 0; |
| uint16_t i, rSz, cp, rem; |
| struct timespec ts; |
| |
| if (!inst) { |
| logw("%s(): Invalid instance\n", __func__); |
| return false; |
| } |
| |
| if (!timespec_get(&ts, TIME_UTC)) { |
| logd("%s(): Filed to retrieve time\n", __func__); |
| return false; |
| } |
| |
| srandom(ts.tv_nsec ^ ts.tv_sec); |
| |
| for (i = 0, rSz = sizeof(r), rem = sizeof(inst->myRandNum); rem > 0; i += cp, rem -= cp) { |
| r = random(); |
| cp = rem > rSz ? rSz : rem; |
| memcpy(&inst->myRandNum.rand[i], &r, cp); |
| } |
| |
| return true; |
| } |
| |
| /* |
| * FUNCTION: smAddressHash |
| * USE: Perform 24bit->24bit hash for address resolution |
| * PARAMS: r - the 24 bits to hash |
| * key - the key |
| * RETURN: the 24-bit hash |
| * NOTES: The SM docs call this the ah() function |
| */ |
| static uint32_t smAddressHash(uint32_t r, const uint8_t *key) |
| { |
| uint8_t in[SM_BLOCK_LEN] = {0,}, out[SM_BLOCK_LEN]; |
| |
| utilSetBE24(in + 13, r); |
| smEncrypt(out, in, key); |
| return utilGetBE24(out + 13); |
| } |
| |
| /* a simple AES-128 implementation - we use it rarely enough that even a nonoptimal version will do */ |
| |
| static void smEncryptSubBytes(uint8_t *bytes, uint8_t num) |
| { |
| static const uint8_t sbox[] = { |
| 0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76, |
| 0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0, |
| 0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15, |
| 0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75, |
| 0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84, |
| 0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF, |
| 0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8, |
| 0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2, |
| 0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73, |
| 0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB, |
| 0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79, |
| 0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08, |
| 0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A, |
| 0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E, |
| 0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF, |
| 0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16, |
| }; |
| uint8_t i; |
| |
| for (i = 0; i < num; i++) |
| bytes[i] = sbox[bytes[i]]; |
| } |
| |
| static void smEncryptShiftRows(uint8_t *state) |
| { |
| uint8_t i, j; |
| uint8_t tmp[4]; |
| |
| for (i = 0; i < 4; i++) { |
| for(j = 0; j < 4; j++) |
| tmp[j] = state[i * 4 + j]; |
| |
| for(j = 0; j < 4; j++) |
| state[i * 4 + j] = tmp[(i + j) & 3]; |
| } |
| } |
| |
| static uint8_t smEncryptMul(uint8_t vin, uint8_t by) |
| { |
| uint16_t v = vin; |
| |
| switch(by){ |
| case 1: |
| break; |
| case 2: |
| v <<= 1; |
| break; |
| case 3: |
| v = (v << 1) ^ v; |
| break; |
| } |
| if (v & 0x100) |
| v ^= 0x1B; |
| |
| return v; |
| } |
| |
| static void smEncryptMixColumns(uint8_t *state) |
| { |
| uint8_t i, j, k, ret[SM_BLOCK_LEN]; |
| static const uint8_t matrix[] = {2,3,1,1,1,2,3,1,1,1,2,3,3,1,1,2}; |
| |
| for (i = 0; i < 4; i++) { |
| for (j = 0; j < 4; j++) { |
| ret[i * 4 + j] = 0; |
| for(k = 0; k < 4; k++) |
| ret[i * 4 + j] ^= smEncryptMul(state[k * 4 + j], matrix[i * 4 + k]); |
| } |
| } |
| |
| for (i = 0; i <SM_BLOCK_LEN; i++) |
| state[i] = ret[i]; |
| } |
| |
| static void smEncryptAddRoundKey(uint8_t *state, const uint8_t *keyPos) |
| { |
| uint8_t i, j; |
| |
| for (i = 0; i < 4; i++, keyPos += 40) |
| for(j = 0; j < 4; j++) |
| *state++ ^= *keyPos++; |
| } |
| |
| static void smEncryptExpandKey(uint8_t *expanded, const uint8_t *key) |
| { |
| static const uint8_t rcon[] = {1,0,0,0, 2,0,0,0, 4,0,0,0, 8,0,0,0, 16,0,0,0, 32,0,0,0, 64,0,0,0, |
| 128,0,0,0, 27,0,0,0, 54,0,0,0}; |
| uint8_t i, j, temp[4]; |
| |
| for(i = 0; i < 4; i++) |
| for(j = 0; j < 4; j++) |
| expanded[i + 44 * j] = key[i * 4 + j]; |
| |
| for (i = 4; i < 44; i++) { |
| for(j = 0; j < 4; j++) |
| temp[j] = expanded[i - 1 + 44 * j]; |
| |
| if (!(i & 3)) { |
| j = temp[0]; |
| temp[0] = temp[1]; |
| temp[1] = temp[2]; |
| temp[2] = temp[3]; |
| temp[3] = j; |
| smEncryptSubBytes(temp, 4); |
| for (j = 0; j < 4; j++) |
| temp[j] ^= rcon[(i &~ 3) - 4 + j]; |
| } |
| |
| for(j = 0; j < 4; j++) |
| expanded[i + 44 * j] = expanded[i - 4 + 44 * j] ^ temp[j]; |
| } |
| } |
| |
| /* |
| * FUNCTION: smEncrypt |
| * USE: Perform an AES-128 encryption |
| * PARAMS: dst - place to store result (SM_ENCRYPT_DATA_LEN bytes) |
| * src - the plain text (SM_ENCRYPT_DATA_LEN bytes) |
| * key - the key (SM_ENCRYPT_DATA_LEN bytes) |
| * RETURN: NONE |
| * NOTES: |
| */ |
| static_or_test void smEncrypt(uint8_t* dst, const uint8_t *src, const uint8_t *key) |
| { |
| uint8_t expandedKey[176]; |
| uint8_t state[SM_BLOCK_LEN]; |
| uint8_t i, j; |
| |
| for(i = 0; i < 4; i++) |
| for(j = 0; j < 4; j++) |
| state[i + 4 * j] = *src++; |
| |
| smEncryptExpandKey(expandedKey, key); |
| |
| |
| smEncryptAddRoundKey(state, expandedKey + 0); |
| |
| for (i = 1; i < 10; i++) { |
| smEncryptSubBytes(state, SM_BLOCK_LEN); |
| smEncryptShiftRows(state); |
| smEncryptMixColumns(state); |
| smEncryptAddRoundKey(state, expandedKey + i * 4); |
| } |
| |
| smEncryptSubBytes(state, SM_BLOCK_LEN); |
| smEncryptShiftRows(state); |
| smEncryptAddRoundKey(state, expandedKey + i * 4); |
| |
| for(i = 0; i < 4; i++) |
| for(j = 0; j < 4; j++) |
| *dst++ = state[i + 4 * j]; |
| } |