Bluetooth: Add SMP function for generating RPAs

We need a function in smp.c to generate Resolvable Random Addresses in
order to support privacy. The local RPA will need to be generated before
advertising, scanning or connecting and regenerated at periodic
intervals. This patch adds the necessary function for RPA generation.

Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index b9eef494fc0af4914298fec20e042dbd2dccb771..79a80f44c832d8afba4c6d5e299edbe6d451f1ca 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -124,6 +124,24 @@ bool smp_irk_matches(struct crypto_blkcipher *tfm, u8 irk[16],
        return !memcmp(bdaddr->b, hash, 3);
 }
 
+int smp_generate_rpa(struct crypto_blkcipher *tfm, u8 irk[16], bdaddr_t *rpa)
+{
+       int err;
+
+       get_random_bytes(&rpa->b[3], 3);
+
+       rpa->b[5] &= 0x3f;      /* Clear two most significant bits */
+       rpa->b[5] |= 0x40;      /* Set second most significant bit */
+
+       err = smp_ah(tfm, irk, &rpa->b[3], rpa->b);
+       if (err < 0)
+               return err;
+
+       BT_DBG("RPA %pMR", rpa);
+
+       return 0;
+}
+
 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])

diff --git a/net/bluetooth/smp.h b/net/bluetooth/smp.h
index d8cc543f523ce77f460eeb42bd7e0be53d8d89ae..f32f1212f650de174e0ef0a66ed352cd7af8aaf8 100644 (file)
--- a/net/bluetooth/smp.h
+++ b/net/bluetooth/smp.h
@@ -152,5 +152,6 @@ void smp_chan_destroy(struct l2cap_conn *conn);
 
 bool smp_irk_matches(struct crypto_blkcipher *tfm, u8 irk[16],
                     bdaddr_t *bdaddr);
+int smp_generate_rpa(struct crypto_blkcipher *tfm, u8 irk[16], bdaddr_t *rpa);
 
 #endif /* __SMP_H */