/* Secure Connections OOB data */
u8 local_pk[64];
u8 local_sk[32];
- u8 local_rr[16];
+ u8 local_rand[16];
bool debug_key;
struct crypto_blkcipher *tfm_aes;
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);
+ get_random_bytes(smp->local_rand, 16);
err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk,
- smp->local_rr, 0, hash);
+ smp->local_rand, 0, hash);
if (err < 0)
return err;
- memcpy(rand, smp->local_rr, 16);
+ memcpy(rand, smp->local_rand, 16);
return 0;
}
oob_flag = SMP_OOB_PRESENT;
memcpy(smp->rr, oob_data->rand256, 16);
memcpy(smp->pcnf, oob_data->hash256, 16);
+ SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
+ SMP_DBG("OOB Remote Random: %16phN", smp->rr);
}
} else {
return 0;
}
+ /* If this function is used for SC -> legacy fallback we
+ * can only recover the just-works case.
+ */
+ if (test_bit(SMP_FLAG_SC, &smp->flags))
+ return -EINVAL;
+
/* Not Just Works/Confirm results in MITM Authentication */
if (smp->method != JUST_CFM) {
set_bit(SMP_FLAG_MITM_AUTH, &smp->flags);
memcpy(&smp->preq[1], req, sizeof(*req));
skb_pull(skb, sizeof(*req));
+ /* If the remote side's OOB flag is set it means it has
+ * successfully received our local OOB data - therefore set the
+ * flag to indicate that local OOB is in use.
+ */
+ if (req->oob_flag == SMP_OOB_PRESENT)
+ set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
+
/* SMP over BR/EDR requires special treatment */
if (conn->hcon->type == ACL_LINK) {
/* We must have a BR/EDR SC link */
clear_bit(SMP_FLAG_INITIATOR, &smp->flags);
+ /* Strictly speaking we shouldn't allow Pairing Confirm for the
+ * SC case, however some implementations incorrectly copy RFU auth
+ * req bits from our security request, which may create a false
+ * positive SC enablement.
+ */
+ SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
+
if (test_bit(SMP_FLAG_SC, &smp->flags)) {
SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY);
/* Clear bits which are generated but not distributed */
return 0;
}
- SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM);
-
/* Request setup of TK */
ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability);
if (ret)
memcpy(smp->local_pk, smp_dev->local_pk, 64);
memcpy(smp->local_sk, smp_dev->local_sk, 32);
- memcpy(smp->lr, smp_dev->local_rr, 16);
+ memcpy(smp->lr, smp_dev->local_rand, 16);
if (smp_dev->debug_key)
set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags);
if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC))
return SMP_AUTH_REQUIREMENTS;
+ /* If the remote side's OOB flag is set it means it has
+ * successfully received our local OOB data - therefore set the
+ * flag to indicate that local OOB is in use.
+ */
+ if (rsp->oob_flag == SMP_OOB_PRESENT)
+ set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags);
+
smp->prsp[0] = SMP_CMD_PAIRING_RSP;
memcpy(&smp->prsp[1], rsp, sizeof(*rsp));
BT_DBG("");
- /* Public Key exchange must happen before any other steps */
- if (!test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
- return SMP_UNSPECIFIED;
-
if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY)
return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM);
return 0;
}
+/* Work-around for some implementations that incorrectly copy RFU bits
+ * from our security request and thereby create the impression that
+ * we're doing SC when in fact the remote doesn't support it.
+ */
+static int fixup_sc_false_positive(struct smp_chan *smp)
+{
+ struct l2cap_conn *conn = smp->conn;
+ struct hci_conn *hcon = conn->hcon;
+ struct hci_dev *hdev = hcon->hdev;
+ struct smp_cmd_pairing *req, *rsp;
+ u8 auth;
+
+ /* The issue is only observed when we're in slave role */
+ if (hcon->out)
+ return SMP_UNSPECIFIED;
+
+ if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) {
+ BT_ERR("Refusing SMP SC -> legacy fallback in SC-only mode");
+ return SMP_UNSPECIFIED;
+ }
+
+ BT_ERR("Trying to fall back to legacy SMP");
+
+ req = (void *) &smp->preq[1];
+ rsp = (void *) &smp->prsp[1];
+
+ /* Rebuild key dist flags which may have been cleared for SC */
+ smp->remote_key_dist = (req->init_key_dist & rsp->resp_key_dist);
+
+ auth = req->auth_req & AUTH_REQ_MASK(hdev);
+
+ if (tk_request(conn, 0, auth, rsp->io_capability, req->io_capability)) {
+ BT_ERR("Failed to fall back to legacy SMP");
+ return SMP_UNSPECIFIED;
+ }
+
+ clear_bit(SMP_FLAG_SC, &smp->flags);
+
+ return 0;
+}
+
static u8 smp_cmd_pairing_confirm(struct l2cap_conn *conn, struct sk_buff *skb)
{
struct l2cap_chan *chan = conn->smp;
memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf));
skb_pull(skb, sizeof(smp->pcnf));
- if (test_bit(SMP_FLAG_SC, &smp->flags))
- return sc_check_confirm(smp);
+ if (test_bit(SMP_FLAG_SC, &smp->flags)) {
+ int ret;
+
+ /* Public Key exchange must happen before any other steps */
+ if (test_bit(SMP_FLAG_REMOTE_PK, &smp->flags))
+ return sc_check_confirm(smp);
+
+ BT_ERR("Unexpected SMP Pairing Confirm");
+
+ ret = fixup_sc_false_positive(smp);
+ if (ret)
+ return ret;
+ }
if (conn->hcon->out) {
smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd),
memcpy(smp->remote_pk, key, 64);
+ if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags)) {
+ err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
+ smp->rr, 0, cfm.confirm_val);
+ if (err)
+ return SMP_UNSPECIFIED;
+
+ if (memcmp(cfm.confirm_val, smp->pcnf, 16))
+ return SMP_CONFIRM_FAILED;
+ }
+
/* Non-initiating device sends its public key after receiving
* the key from the initiating device.
*/
}
SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk);
- SMP_DBG("Remote Public Key Y: %32phN", &smp->remote_pk[32]);
+ SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32);
if (!ecdh_shared_secret(smp->remote_pk, smp->local_sk, smp->dhkey))
return SMP_UNSPECIFIED;
}
if (smp->method == REQ_OOB) {
- err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->remote_pk,
- smp->rr, 0, cfm.confirm_val);
- if (err)
- return SMP_UNSPECIFIED;
-
- if (memcmp(cfm.confirm_val, smp->pcnf, 16))
- return SMP_CONFIRM_FAILED;
-
if (hcon->out)
smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM,
sizeof(smp->prnd), smp->prnd);
create_chan:
chan = l2cap_chan_create();
if (!chan) {
- crypto_free_blkcipher(smp->tfm_aes);
- crypto_free_hash(smp->tfm_cmac);
- kzfree(smp);
+ if (smp) {
+ crypto_free_blkcipher(smp->tfm_aes);
+ crypto_free_hash(smp->tfm_cmac);
+ kzfree(smp);
+ }
return ERR_PTR(-ENOMEM);
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff