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Bluetooth: SMP: Add support for tracking pairing method

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This allows to track which pairing method was used and is
a preparation for storing information if resulting keys
are authenticated.

Change-Id: Ib9fc762d19bd4add6f0b431745eeb9e2780016d4
Signed-off-by: Szymon Janc <ext.szymon.janc@tieto.com>
This commit is contained in:
Szymon Janc 2015-08-17 12:19:13 +02:00 • committed by Anas Nashif
commit 7d392f7a6d
1 changed files with 66 additions and 20 deletions
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86
net/bluetooth/smp.c
View file

@ -54,6 +54,13 @@
#define RECV_KEYS (BT_SMP_DIST_ID_KEY | BT_SMP_DIST_ENC_KEY | BT_SMP_DIST_SIGN)
#define SEND_KEYS (BT_SMP_DIST_ENC_KEY | BT_SMP_DIST_SIGN)
enum pairing_method {
JUST_WORKS, /* JustWorks pairing */
PASSKEY_INPUT, /* Passkey Entry input */
PASSKEY_DISPLAY, /* Passkey Entry display */
PASSKEY_ROLE, /* Passkey Entry depends on role */
} ;
/* SMP channel specific context */
struct bt_smp {
/* The connection this context is associated with */
@ -65,6 +72,9 @@ struct bt_smp {
/* If we're waiting for an encryption change event */
bool pending_encrypt;
/* Type of method used for pairing */
uint8_t method;
/* Pairing Request PDU */
uint8_t preq[7];
@ -90,10 +100,44 @@ struct bt_smp {
uint8_t remote_dist;
};
/* based on table 2.8 Core Spec 2.3.5.1 Vol. 3 Part H */
static const uint8_t gen_method[5 /* remote */][5 /* local */] = {
{ JUST_WORKS, JUST_WORKS, PASSKEY_INPUT, JUST_WORKS, PASSKEY_INPUT },
{ JUST_WORKS, JUST_WORKS, PASSKEY_INPUT, JUST_WORKS, PASSKEY_INPUT },
{ PASSKEY_DISPLAY, PASSKEY_DISPLAY, PASSKEY_INPUT, JUST_WORKS,
PASSKEY_INPUT },
{ JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS, JUST_WORKS },
{ PASSKEY_DISPLAY, PASSKEY_DISPLAY, PASSKEY_INPUT, JUST_WORKS,
PASSKEY_ROLE },
};
static struct bt_smp bt_smp_pool[CONFIG_BLUETOOTH_MAX_CONN];
static const struct bt_auth_cb *auth_cb;
static uint8_t bt_smp_io_capa = BT_SMP_IO_NO_INPUT_OUTPUT;
static uint8_t get_pair_method(struct bt_smp *smp, uint8_t remote_io)
{
uint8_t method;
if (remote_io > BT_SMP_IO_KEYBOARD_DISPLAY)
return JUST_WORKS;
method = gen_method[remote_io][bt_smp_io_capa];
/* if both sides have KeyboardDisplay capabilities, initiator displays
* and responder inputs
*/
if (method == PASSKEY_ROLE) {
if (smp->conn->role == BT_HCI_ROLE_MASTER) {
method = PASSKEY_DISPLAY;
} else {
method = PASSKEY_INPUT;
}
}
return method;
}
#if defined(CONFIG_BLUETOOTH_DEBUG_SMP)
/* Helper for printk parameters to convert from binary to hex.
* We declare multiple buffers so the helper can be used multiple times
@ -356,31 +400,32 @@ static uint8_t get_auth(uint8_t auth)
static uint8_t smp_request_tk(struct bt_conn *conn, uint8_t remote_io)
{
struct bt_smp *smp = conn->smp;
uint32_t passkey;
/* TODO for now keep it simple, should be refactored (eg with lookup
* table) when more capabilities options will be supported
*/
smp->method = get_pair_method(smp, remote_io);
switch (bt_smp_io_capa) {
case BT_SMP_IO_DISPLAY_ONLY:
if (remote_io == BT_SMP_IO_KEYBOARD_DISPLAY ||
remote_io == BT_SMP_IO_KEYBOARD_ONLY) {
uint32_t passkey;
if (le_rand(&passkey, sizeof(passkey))) {
return BT_SMP_ERR_UNSPECIFIED;
}
passkey %= 1000000;
auth_cb->passkey_display(conn, passkey);
passkey = sys_cpu_to_le32(passkey);
memcpy(smp->tk, &passkey, sizeof(passkey));
switch (smp->method) {
case PASSKEY_DISPLAY:
if (le_rand(&passkey, sizeof(passkey))) {
return BT_SMP_ERR_UNSPECIFIED;
}
passkey %= 1000000;
auth_cb->passkey_display(conn, passkey);
passkey = sys_cpu_to_le32(passkey);
memcpy(smp->tk, &passkey, sizeof(passkey));
break;
case PASSKEY_INPUT:
/* TODO add support for input passkey entry*/
return BT_SMP_ERR_UNSPECIFIED;
case JUST_WORKS:
break;
default:
break;
BT_ERR("Unknown pairing method (%u)\n", smp->method);
return BT_SMP_ERR_UNSPECIFIED;
}
return 0;
@ -686,6 +731,7 @@ static void smp_reset(struct bt_conn *conn)
{
struct bt_smp *smp = conn->smp;
smp->method = JUST_WORKS;
atomic_set(&smp->allowed_cmds, 0);
if (conn->role == BT_HCI_ROLE_MASTER) {