Bluetooth: Add SMP confirmation checks methods

This patch includes support for generating and sending the random value
used to produce the confirmation value.

Signed-off-by: Anderson Briglia <anderson.briglia@openbossa.org>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@openbossa.org>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
index b03d9c4dfc789d59c983e6e85624a2c4618c8aae..01c993b6b2635f45ce80c4f6a72bdbf593b825f1 100644 (file)
--- a/include/net/bluetooth/l2cap.h
+++ b/include/net/bluetooth/l2cap.h
@@ -399,6 +399,7 @@ struct l2cap_conn {
        __u8            prsp[7]; /* SMP Pairing Response */
        __u8            prnd[16]; /* SMP Pairing Random */
        __u8            pcnf[16]; /* SMP Pairing Confirm */
+       __u8            tk[16]; /* SMP Temporary Key */
 
        struct list_head chan_l;
        rwlock_t        chan_lock;

diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index fa22f4aa3b04c0c7952abe096a2fe7fd2bea8dcc..7a9a195c27d370f09557be3a2168094f8735945a 100644 (file)
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -198,6 +198,9 @@ static void smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
        rp->resp_key_dist = 0x00;
        rp->auth_req &= (SMP_AUTH_BONDING | SMP_AUTH_MITM);
 
+       /* Just works */
+       memset(conn->tk, 0, sizeof(conn->tk));
+
        conn->prsp[0] = SMP_CMD_PAIRING_RSP;
        memcpy(&conn->prsp[1], rp, sizeof(*rp));
 
@@ -208,54 +211,120 @@ static void smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
 {
        struct smp_cmd_pairing *rp = (void *) skb->data;
        struct smp_cmd_pairing_confirm cp;
+       struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm;
+       int ret;
+       u8 res[16];
 
        BT_DBG("conn %p", conn);
 
-       memset(&cp, 0, sizeof(cp));
+       /* Just works */
+       memset(conn->tk, 0, sizeof(conn->tk));
 
        conn->prsp[0] = SMP_CMD_PAIRING_RSP;
        memcpy(&conn->prsp[1], rp, sizeof(*rp));
        skb_pull(skb, sizeof(*rp));
 
+       ret = smp_rand(conn->prnd);
+       if (ret)
+               return;
+
+       ret = smp_c1(tfm, conn->tk, conn->prnd, conn->preq, conn->prsp, 0,
+                       conn->src, conn->hcon->dst_type, conn->dst, res);
+       if (ret)
+               return;
+
+       swap128(res, cp.confirm_val);
+
        smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
 }
 
 static void smp_cmd_pairing_confirm(struct l2cap_conn *conn,
                                                        struct sk_buff *skb)
 {
+       struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm;
+
        BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
 
-       if (conn->hcon->out) {
-               struct smp_cmd_pairing_random random;
+       memcpy(conn->pcnf, skb->data, sizeof(conn->pcnf));
+       skb_pull(skb, sizeof(conn->pcnf));
 
-               memset(&random, 0, sizeof(random));
+       if (conn->hcon->out) {
+               u8 random[16];
 
+               swap128(conn->prnd, random);
                smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random),
-                                                               &random);
+                                                               random);
        } else {
-               struct smp_cmd_pairing_confirm confirm;
+               struct smp_cmd_pairing_confirm cp;
+               int ret;
+               u8 res[16];
 
-               memset(&confirm, 0, sizeof(confirm));
+               ret = smp_rand(conn->prnd);
+               if (ret)
+                       return;
 
-               smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(confirm),
-                                                               &confirm);
+               ret = smp_c1(tfm, conn->tk, conn->prnd, conn->preq, conn->prsp,
+                                               conn->hcon->dst_type, conn->dst,
+                                               0, conn->src, res);
+               if (ret)
+                       return;
+
+               swap128(res, cp.confirm_val);
+
+               smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
        }
 }
 
 static void smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
 {
-       struct smp_cmd_pairing_random cp;
+       struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm;
+       int ret;
+       u8 key[16], res[16], random[16], confirm[16], buf[128];
+
+       swap128(skb->data, random);
+       skb_pull(skb, sizeof(random));
+
+       if (conn->hcon->out)
+               ret = smp_c1(tfm, conn->tk, random, conn->preq, conn->prsp, 0,
+                               conn->src, conn->hcon->dst_type, conn->dst,
+                               res);
+       else
+               ret = smp_c1(tfm, conn->tk, random, conn->preq, conn->prsp,
+                               conn->hcon->dst_type, conn->dst, 0, conn->src,
+                               res);
+       if (ret)
+               return;
 
        BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
 
-       skb_pull(skb, sizeof(cp));
+       swap128(res, confirm);
+
+       if (memcmp(conn->pcnf, confirm, sizeof(conn->pcnf)) != 0) {
+               struct smp_cmd_pairing_fail cp;
+
+               BT_ERR("Pairing failed (confirmation values mismatch)");
+               cp.reason = SMP_CONFIRM_FAILED;
+               smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(cp), &cp);
+               return;
+       }
 
        if (conn->hcon->out) {
-               /* FIXME: start encryption */
+               smp_s1(tfm, conn->tk, random, conn->prnd, key);
+
+               hex_dump_to_buffer(key, sizeof(key), 16, 1, buf,
+                                                       sizeof(buf), 0);
+               BT_DBG("key %s", buf);
        } else {
-               memset(&cp, 0, sizeof(cp));
+               u8 r[16];
+
+               swap128(conn->prnd, r);
+               smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(r), r);
+
+               smp_s1(tfm, conn->tk, conn->prnd, random, key);
 
-               smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(cp), &cp);
+               hex_dump_to_buffer(key, sizeof(key), 16, 1, buf,
+                                                       sizeof(buf), 0);
+               BT_DBG("key %s", buf);
        }
 }