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Commit 60478054 authored by Johan Hedberg's avatar Johan Hedberg Committed by Marcel Holtmann
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Bluetooth: Add smp_irk_matches helper function 



This patch adds a helper function to check whether a given IRK matches a
given Resolvable Private Address (RPA). The function will be needed for
implementing the rest of address resolving support.

Signed-off-by: default avatarJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
parent 6bfdfe3c

net/bluetooth/smp.c

+46 −0
Original line number Diff line number Diff line
@@ -78,6 +78,52 @@ static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r) 
	return err;

}



static int smp_ah(struct crypto_blkcipher *tfm, u8 irk[16], u8 r[3], u8 res[3])

{

	u8 _res[16], k[16];

	int err;



	/* r' = padding || r */

	memset(_res, 0, 13);

	_res[13] = r[2];

	_res[14] = r[1];

	_res[15] = r[0];



	swap128(irk, k);

	err = smp_e(tfm, k, _res);

	if (err) {

		BT_ERR("Encrypt error");

		return err;

	}



	/* The output of the random address function ah is:

	 *	ah(h, r) = e(k, r') mod 2^24

	 * The output of the security function e is then truncated to 24 bits

	 * by taking the least significant 24 bits of the output of e as the

	 * result of ah.

	 */

	res[0] = _res[15];

	res[1] = _res[14];

	res[2] = _res[13];



	return 0;

}



bool smp_irk_matches(struct crypto_blkcipher *tfm, u8 irk[16],

		     bdaddr_t *bdaddr)

{

	u8 hash[3];

	int err;



	BT_DBG("RPA %pMR IRK %*phN", bdaddr, 16, irk);



	err = smp_ah(tfm, irk, &bdaddr->b[3], hash);

	if (err)

		return false;



	return !memcmp(bdaddr->b, hash, 3);

}



static int smp_c1(struct crypto_blkcipher *tfm, u8 k[16], u8 r[16],

		  u8 preq[7], u8 pres[7], u8 _iat, bdaddr_t *ia,

		  u8 _rat, bdaddr_t *ra, u8 res[16])

net/bluetooth/smp.h

+3 −0
Original line number Diff line number Diff line
@@ -143,4 +143,7 @@ int smp_user_confirm_reply(struct hci_conn *conn, u16 mgmt_op, __le32 passkey); 


void smp_chan_destroy(struct l2cap_conn *conn);



bool smp_irk_matches(struct crypto_blkcipher *tfm, u8 irk[16],

		     bdaddr_t *bdaddr);



#endif /* __SMP_H */