diff options
| -rw-r--r-- | net/bluetooth/smp.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c index 103f05aff7e9..b12f076d78b1 100644 --- a/net/bluetooth/smp.c +++ b/net/bluetooth/smp.c @@ -84,6 +84,7 @@ struct smp_chan { u8 local_sk[32]; u8 remote_pk[64]; u8 dhkey[32]; + u8 mackey[16]; struct crypto_blkcipher *tfm_aes; struct crypto_hash *tfm_cmac; @@ -175,6 +176,86 @@ static int smp_f4(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32], return err; } +static int smp_f5(struct crypto_hash *tfm_cmac, u8 w[32], u8 n1[16], u8 n2[16], + u8 a1[7], u8 a2[7], u8 mackey[16], u8 ltk[16]) +{ + /* The btle, salt and length "magic" values are as defined in + * the SMP section of the Bluetooth core specification. In ASCII + * the btle value ends up being 'btle'. The salt is just a + * random number whereas length is the value 256 in little + * endian format. + */ + const u8 btle[4] = { 0x65, 0x6c, 0x74, 0x62 }; + const u8 salt[16] = { 0xbe, 0x83, 0x60, 0x5a, 0xdb, 0x0b, 0x37, 0x60, + 0x38, 0xa5, 0xf5, 0xaa, 0x91, 0x83, 0x88, 0x6c }; + const u8 length[2] = { 0x00, 0x01 }; + u8 m[53], t[16]; + int err; + + BT_DBG("w %32phN", w); + BT_DBG("n1 %16phN n2 %16phN", n1, n2); + BT_DBG("a1 %7phN a2 %7phN", a1, a2); + + err = aes_cmac(tfm_cmac, salt, w, 32, t); + if (err) + return err; + + BT_DBG("t %16phN", t); + + memcpy(m, length, 2); + memcpy(m + 2, a2, 7); + memcpy(m + 9, a1, 7); + memcpy(m + 16, n2, 16); + memcpy(m + 32, n1, 16); + memcpy(m + 48, btle, 4); + + m[52] = 0; /* Counter */ + + err = aes_cmac(tfm_cmac, t, m, sizeof(m), mackey); + if (err) + return err; + + BT_DBG("mackey %16phN", mackey); + + m[52] = 1; /* Counter */ + + err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); + if (err) + return err; + + BT_DBG("ltk %16phN", ltk); + + return 0; +} + +static int smp_f6(struct crypto_hash *tfm_cmac, const u8 w[16], + const u8 n1[16], u8 n2[16], const u8 r[16], + const u8 io_cap[3], const u8 a1[7], const u8 a2[7], + u8 res[16]) +{ + u8 m[65]; + int err; + + BT_DBG("w %16phN", w); + BT_DBG("n1 %16phN n2 %16phN", n1, n2); + BT_DBG("r %16phN io_cap %3phN a1 %7phN a2 %7phN", r, io_cap, a1, a2); + + memcpy(m, a2, 7); + memcpy(m + 7, a1, 7); + memcpy(m + 14, io_cap, 3); + memcpy(m + 17, r, 16); + memcpy(m + 33, n2, 16); + memcpy(m + 49, n1, 16); + + err = aes_cmac(tfm_cmac, w, m, sizeof(m), res); + if (err) + return err; + + BT_DBG("res %16phN", res); + + return err; +} + static int smp_g2(struct crypto_hash *tfm_cmac, const u8 u[32], const u8 v[32], const u8 x[16], const u8 y[16], u32 *val) { @@ -1001,6 +1082,69 @@ static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) return smp; } +static int sc_mackey_and_ltk(struct smp_chan *smp, u8 mackey[16], u8 ltk[16]) +{ + struct hci_conn *hcon = smp->conn->hcon; + u8 *na, *nb, a[7], b[7]; + + if (hcon->out) { + na = smp->prnd; + nb = smp->rrnd; + } else { + na = smp->rrnd; + nb = smp->prnd; + } + + memcpy(a, &hcon->init_addr, 6); + memcpy(b, &hcon->resp_addr, 6); + a[6] = hcon->init_addr_type; + b[6] = hcon->resp_addr_type; + + return smp_f5(smp->tfm_cmac, smp->dhkey, na, nb, a, b, mackey, ltk); +} + +static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) +{ + struct hci_conn *hcon = smp->conn->hcon; + struct smp_cmd_dhkey_check check; + u8 a[7], b[7], *local_addr, *remote_addr; + u8 io_cap[3], r[16]; + + switch (mgmt_op) { + case MGMT_OP_USER_PASSKEY_NEG_REPLY: + smp_failure(smp->conn, SMP_PASSKEY_ENTRY_FAILED); + return 0; + case MGMT_OP_USER_CONFIRM_NEG_REPLY: + smp_failure(smp->conn, SMP_NUMERIC_COMP_FAILED); + return 0; + } + + memcpy(a, &hcon->init_addr, 6); + memcpy(b, &hcon->resp_addr, 6); + a[6] = hcon->init_addr_type; + b[6] = hcon->resp_addr_type; + + if (hcon->out) { + local_addr = a; + remote_addr = b; + memcpy(io_cap, &smp->preq[1], 3); + } else { + local_addr = b; + remote_addr = a; + memcpy(io_cap, &smp->prsp[1], 3); + } + + memcpy(r, &passkey, sizeof(passkey)); + memset(r + sizeof(passkey), 0, sizeof(r) - sizeof(passkey)); + + smp_f6(smp->tfm_cmac, smp->mackey, smp->prnd, smp->rrnd, r, io_cap, + local_addr, remote_addr, check.e); + + smp_send_cmd(smp->conn, SMP_CMD_DHKEY_CHECK, sizeof(check), &check); + + return 0; +} + int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) { struct l2cap_conn *conn = hcon->l2cap_data; @@ -1026,6 +1170,11 @@ int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) smp = chan->data; + if (test_bit(SMP_FLAG_SC, &smp->flags)) { + err = sc_user_reply(smp, mgmt_op, passkey); + goto unlock; + } + switch (mgmt_op) { case MGMT_OP_USER_PASSKEY_REPLY: value = le32_to_cpu(passkey); @@ -1338,6 +1487,11 @@ static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) nb = smp->prnd; } + /* Generate MacKey and LTK */ + err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); + if (err) + return SMP_UNSPECIFIED; + err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); if (err) return SMP_UNSPECIFIED; |