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| author | Johan Hedberg <johan.hedberg@intel.com> | 2014-02-18 09:19:31 +0100 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2014-02-18 09:47:02 +0100 |
| commit | 60478054a6af7aa8cceb8218d29d27f165f1c9d3 (patch) | |
| tree | cf713df16202dade0f90d6c00fd6eb8dd2d24592 /net | |
| parent | Bluetooth: Fix minor whitespace issues in SMP code (diff) | |
| download | linux-60478054a6af7aa8cceb8218d29d27f165f1c9d3.tar.xz linux-60478054a6af7aa8cceb8218d29d27f165f1c9d3.zip | |
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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/bluetooth/smp.c | 46 | ||||
| -rw-r--r-- | net/bluetooth/smp.h | 3 |
2 files changed, 49 insertions, 0 deletions
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index ae487e17380e..5f500b479f45 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -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]) diff --git a/net/bluetooth/smp.h b/net/bluetooth/smp.h index 777ee93a6c9b..950d039c2ea2 100644 --- a/net/bluetooth/smp.h +++ b/net/bluetooth/smp.h @@ -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 */ |