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Commit 60a27d65 authored by Marcel Holtmann's avatar Marcel Holtmann Committed by Johan Hedberg
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Bluetooth: Add function for generating LE SC out-of-band data 



This patch adds a smp_generate_oob function that allows to create
local out-of-band data that can be used for pairing and also provides
the confirmation and random value.

Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
parent 6e2dc6d1

net/bluetooth/smp.c

+53 −0
Original line number Diff line number Diff line
@@ -74,6 +74,12 @@ enum { 
};



struct smp_dev {

	/* Secure Connections OOB data */

	u8			local_pk[64];

	u8			local_sk[32];

	u8			local_rr[16];

	bool			debug_key;



	struct crypto_blkcipher	*tfm_aes;

	struct crypto_hash	*tfm_cmac;

};
@@ -526,6 +532,53 @@ int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) 
	return 0;

}



int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16])

{

	struct l2cap_chan *chan = hdev->smp_data;

	struct smp_dev *smp;

	int err;



	if (!chan || !chan->data)

		return -EOPNOTSUPP;



	smp = chan->data;



	if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) {

		BT_DBG("Using debug keys");

		memcpy(smp->local_pk, debug_pk, 64);

		memcpy(smp->local_sk, debug_sk, 32);

		smp->debug_key = true;

	} else {

		while (true) {

			/* Generate local key pair for Secure Connections */

			if (!ecc_make_key(smp->local_pk, smp->local_sk))

				return -EIO;



			/* This is unlikely, but we need to check that

			 * we didn't accidentially generate a debug key.

			 */

			if (memcmp(smp->local_sk, debug_sk, 32))

				break;

		}

		smp->debug_key = false;

	}



	SMP_DBG("OOB Public Key X: %32phN", smp->local_pk);

	SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32);

	SMP_DBG("OOB Private Key:  %32phN", smp->local_sk);



	get_random_bytes(smp->local_rr, 16);



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

		     smp->local_rr, 0, hash);

	if (err < 0)

		return err;



	memcpy(rand, smp->local_rr, 16);



	return 0;

}



static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)

{

	struct l2cap_chan *chan = conn->smp;

net/bluetooth/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ int smp_user_confirm_reply(struct hci_conn *conn, u16 mgmt_op, __le32 passkey); 
bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16],

		     const bdaddr_t *bdaddr);

int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa);

int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]);



int smp_register(struct hci_dev *hdev);

void smp_unregister(struct hci_dev *hdev);