Bluetooth: Add selection of the SC authentication method (5e3d3d9b) · Commits · 戴 / test

net/bluetooth/smp.c

+69 −5

Original line number	Diff line number	Diff line
		@@ -661,6 +661,7 @@ static void smp_failure(struct l2cap_conn *conn, u8 reason)
		#define REQ_PASSKEY 0x02
		#define CFM_PASSKEY 0x03
		#define REQ_OOB 0x04
		#define DSP_PASSKEY 0x05
		#define OVERLAP 0xFF

		static const u8 gen_method[5][5] = {
		@@ -671,6 +672,14 @@ static const u8 gen_method[5][5] = {
		{ CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP },
		};

		static const u8 sc_method[5][5] = {
		{ JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY },
		{ JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
		{ DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY },
		{ JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM },
		{ DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY },
		};

		static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
		{
		/* If either side has unknown io_caps, use JUST_CFM (which gets
		@@ -680,6 +689,9 @@ static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io)
		remote_io > SMP_IO_KEYBOARD_DISPLAY)
		return JUST_CFM;

		if (test_bit(SMP_FLAG_SC, &smp->flags))
		return sc_method[remote_io][local_io];

		return gen_method[remote_io][local_io];
		}

		@@ -1305,6 +1317,11 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn conn, struct sk_buff skb)
		memcpy(&smp->preq[1], req, sizeof(*req));
		skb_pull(skb, sizeof(*req));

		build_pairing_cmd(conn, req, &rsp, auth);

		if (rsp.auth_req & SMP_AUTH_SC)
		set_bit(SMP_FLAG_SC, &smp->flags);

		if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT)
		sec_level = BT_SECURITY_MEDIUM;
		else
		@@ -1323,11 +1340,6 @@ static u8 smp_cmd_pairing_req(struct l2cap_conn conn, struct sk_buff skb)
		return SMP_AUTH_REQUIREMENTS;
		}

		build_pairing_cmd(conn, req, &rsp, auth);

		if (rsp.auth_req & SMP_AUTH_SC)
		set_bit(SMP_FLAG_SC, &smp->flags);

		key_size = min(req->max_key_size, rsp.max_key_size);
		if (check_enc_key_size(conn, key_size))
		return SMP_ENC_KEY_SIZE;
		@@ -1901,12 +1913,54 @@ static int smp_cmd_sign_info(struct l2cap_conn conn, struct sk_buff skb)
		return 0;
		}

		static u8 sc_select_method(struct smp_chan *smp)
		{
		struct l2cap_conn *conn = smp->conn;
		struct hci_conn *hcon = conn->hcon;
		struct smp_cmd_pairing local, remote;
		u8 local_mitm, remote_mitm, local_io, remote_io, method;

		/* 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
		* first byte which contains the opcode.
		*/
		if (hcon->out) {
		local = (void *) &smp->preq[1];
		remote = (void *) &smp->prsp[1];
		} else {
		local = (void *) &smp->prsp[1];
		remote = (void *) &smp->preq[1];
		}

		local_io = local->io_capability;
		remote_io = remote->io_capability;

		local_mitm = (local->auth_req & SMP_AUTH_MITM);
		remote_mitm = (remote->auth_req & SMP_AUTH_MITM);

		/* If either side wants MITM, look up the method from the table,
		* otherwise use JUST WORKS.
		*/
		if (local_mitm \|\| remote_mitm)
		method = get_auth_method(smp, local_io, remote_io);
		else
		method = JUST_WORKS;

		/* Don't confirm locally initiated pairing attempts */
		if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags))
		method = JUST_WORKS;

		return method;
		}

		static int smp_cmd_public_key(struct l2cap_conn conn, struct sk_buff skb)
		{
		struct smp_cmd_public_key key = (void ) skb->data;
		struct hci_conn *hcon = conn->hcon;
		struct l2cap_chan *chan = conn->smp;
		struct smp_chan *smp = chan->data;
		struct hci_dev *hdev = hcon->hdev;
		struct smp_cmd_pairing_confirm cfm;
		int err;

		@@ -1936,6 +1990,16 @@ static int smp_cmd_public_key(struct l2cap_conn conn, struct sk_buff skb)

		set_bit(SMP_FLAG_REMOTE_PK, &smp->flags);

		smp->method = sc_select_method(smp);

		BT_DBG("%s selected method 0x%02x", hdev->name, smp->method);

		/* JUST_WORKS and JUST_CFM result in an unauthenticated key */
		if (smp->method == JUST_WORKS \|\| smp->method == JUST_CFM)
		hcon->pending_sec_level = BT_SECURITY_MEDIUM;
		else
		hcon->pending_sec_level = BT_SECURITY_FIPS;

		/* The Initiating device waits for the non-initiating device to
		* send the confirm value.
		*/

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