Commit a29b0733 authored by Johan Hedberg's avatar Johan Hedberg Committed by Marcel Holtmann
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Bluetooth: Add basic LE SC OOB support for remote OOB data 



This patch adds basic OOB pairing support when we've received the remote
OOB data. This includes tracking the remote r value (in smp->rr) as well
as doing the appropriate f4() call when needed. Previously the OOB rand
would have been stored in smp->rrnd however these are actually two
independent values so we need separate variables for them. Na/Nb in the
spec maps to smp->prnd/rrnd and ra/rb maps to smp->rr with smp->pr to
come once local OOB data is supported.

Signed-off-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent 02b05bd8

net/bluetooth/smp.c

+36 −2
Original line number Diff line number Diff line
@@ -71,6 +71,7 @@ struct smp_chan { 
	u8		rrnd[16]; /* SMP Pairing Random (remote) */

	u8		pcnf[16]; /* SMP Pairing Confirm */

	u8		tk[16]; /* SMP Temporary Key */

	u8		rr[16];

	u8		enc_key_size;

	u8		remote_key_dist;

	bdaddr_t	id_addr;
@@ -599,7 +600,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn, 
		if (oob_data) {

			set_bit(SMP_FLAG_OOB, &smp->flags);

			oob_flag = SMP_OOB_PRESENT;

			memcpy(smp->rrnd, oob_data->rand256, 16);

			memcpy(smp->rr, oob_data->rand256, 16);

			memcpy(smp->pcnf, oob_data->hash256, 16);

		}
@@ -1334,6 +1335,9 @@ static void sc_dhkey_check(struct smp_chan *smp) 
	if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)

		put_unaligned_le32(hcon->passkey_notify, r);



	if (smp->method == REQ_OOB)

		memcpy(r, smp->rr, 16);



	smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap,

	       local_addr, remote_addr, check.e);
@@ -1910,6 +1914,14 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 
	if (!test_bit(SMP_FLAG_SC, &smp->flags))

		return smp_random(smp);



	if (smp->method == REQ_OOB) {

		if (!hcon->out)

			smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,

				     sizeof(smp->prnd), smp->prnd);

		SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);

		goto mackey_and_ltk;

	}



	/* Passkey entry has special treatment */

	if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)

		return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM);
@@ -1940,12 +1952,13 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) 
		nb   = smp->prnd;

	}



mackey_and_ltk:

	/* Generate MacKey and LTK */

	err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk);

	if (err)

		return SMP_UNSPECIFIED;



	if (smp->method == JUST_WORKS) {

	if (smp->method == JUST_WORKS || smp->method == REQ_OOB) {

		if (hcon->out) {

			sc_dhkey_check(smp);

			SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK);
@@ -2314,6 +2327,9 @@ static u8 sc_select_method(struct smp_chan *smp) 
	struct smp_cmd_pairing *local, *remote;

	u8 local_mitm, remote_mitm, local_io, remote_io, method;



	if (test_bit(SMP_FLAG_OOB, &smp->flags))

		return REQ_OOB;



	/* The preq/prsp contain the raw Pairing Request/Response PDUs

	 * which are needed as inputs to some crypto functions. To get

	 * the "struct smp_cmd_pairing" from them we need to skip the
@@ -2412,6 +2428,24 @@ static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) 
		return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY);

	}



	if (smp->method == REQ_OOB) {

		err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,

			     smp->rr, 0, cfm.confirm_val);

		if (err)

			return SMP_UNSPECIFIED;



		if (memcmp(cfm.confirm_val, smp->pcnf, 16))

			return SMP_CONFIRM_FAILED;



		if (hcon->out)

			smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,

				     sizeof(smp->prnd), smp->prnd);



		SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM);



		return 0;

	}



	if (hcon->out)

		SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);

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