1 files changed, 534 insertions, 0 deletions
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
new file mode 100644
index 000000000000..a36f8707d964
--- /dev/null
+++ b/net/bluetooth/smp.c
@@ -0,0 +1,534 @@
+/*
+   BlueZ - Bluetooth protocol stack for Linux
+   Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License version 2 as
+   published by the Free Software Foundation;
+
+   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+   OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
+   IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
+   CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+   OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+   ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
+   COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
+   SOFTWARE IS DISCLAIMED.
+*/
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+#include <net/bluetooth/l2cap.h>
+#include <net/bluetooth/smp.h>
+#include <linux/crypto.h>
+#include <linux/scatterlist.h>
+#include <crypto/b128ops.h>
+
+#define SMP_TIMEOUT 30000 /* 30 seconds */
+
+static inline void swap128(u8 src[16], u8 dst[16])
+{
+	int i;
+	for (i = 0; i < 16; i++)
+		dst[15 - i] = src[i];
+}
+
+static inline void swap56(u8 src[7], u8 dst[7])
+{
+	int i;
+	for (i = 0; i < 7; i++)
+		dst[6 - i] = src[i];
+}
+
+static int smp_e(struct crypto_blkcipher *tfm, const u8 *k, u8 *r)
+{
+	struct blkcipher_desc desc;
+	struct scatterlist sg;
+	int err, iv_len;
+	unsigned char iv[128];
+
+	if (tfm == NULL) {
+		BT_ERR("tfm %p", tfm);
+		return -EINVAL;
+	}
+
+	desc.tfm = tfm;
+	desc.flags = 0;
+
+	err = crypto_blkcipher_setkey(tfm, k, 16);
+	if (err) {
+		BT_ERR("cipher setkey failed: %d", err);
+		return err;
+	}
+
+	sg_init_one(&sg, r, 16);
+
+	iv_len = crypto_blkcipher_ivsize(tfm);
+	if (iv_len) {
+		memset(&iv, 0xff, iv_len);
+		crypto_blkcipher_set_iv(tfm, iv, iv_len);
+	}
+
+	err = crypto_blkcipher_encrypt(&desc, &sg, &sg, 16);
+	if (err)
+		BT_ERR("Encrypt data error %d", err);
+
+	return err;
+}
+
+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])
+{
+	u8 p1[16], p2[16];
+	int err;
+
+	memset(p1, 0, 16);
+
+	/* p1 = pres || preq || _rat || _iat */
+	swap56(pres, p1);
+	swap56(preq, p1 + 7);
+	p1[14] = _rat;
+	p1[15] = _iat;
+
+	memset(p2, 0, 16);
+
+	/* p2 = padding || ia || ra */
+	baswap((bdaddr_t *) (p2 + 4), ia);
+	baswap((bdaddr_t *) (p2 + 10), ra);
+
+	/* res = r XOR p1 */
+	u128_xor((u128 *) res, (u128 *) r, (u128 *) p1);
+
+	/* res = e(k, res) */
+	err = smp_e(tfm, k, res);
+	if (err) {
+		BT_ERR("Encrypt data error");
+		return err;
+	}
+
+	/* res = res XOR p2 */
+	u128_xor((u128 *) res, (u128 *) res, (u128 *) p2);
+
+	/* res = e(k, res) */
+	err = smp_e(tfm, k, res);
+	if (err)
+		BT_ERR("Encrypt data error");
+
+	return err;
+}
+
+static int smp_s1(struct crypto_blkcipher *tfm, u8 k[16],
+			u8 r1[16], u8 r2[16], u8 _r[16])
+{
+	int err;
+
+	/* Just least significant octets from r1 and r2 are considered */
+	memcpy(_r, r1 + 8, 8);
+	memcpy(_r + 8, r2 + 8, 8);
+
+	err = smp_e(tfm, k, _r);
+	if (err)
+		BT_ERR("Encrypt data error");
+
+	return err;
+}
+
+static int smp_rand(u8 *buf)
+{
+	get_random_bytes(buf, 16);
+
+	return 0;
+}
+
+static struct sk_buff *smp_build_cmd(struct l2cap_conn *conn, u8 code,
+						u16 dlen, void *data)
+{
+	struct sk_buff *skb;
+	struct l2cap_hdr *lh;
+	int len;
+
+	len = L2CAP_HDR_SIZE + sizeof(code) + dlen;
+
+	if (len > conn->mtu)
+		return NULL;
+
+	skb = bt_skb_alloc(len, GFP_ATOMIC);
+	if (!skb)
+		return NULL;
+
+	lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
+	lh->len = cpu_to_le16(sizeof(code) + dlen);
+	lh->cid = cpu_to_le16(L2CAP_CID_SMP);
+
+	memcpy(skb_put(skb, sizeof(code)), &code, sizeof(code));
+
+	memcpy(skb_put(skb, dlen), data, dlen);
+
+	return skb;
+}
+
+static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data)
+{
+	struct sk_buff *skb = smp_build_cmd(conn, code, len, data);
+
+	BT_DBG("code 0x%2.2x", code);
+
+	if (!skb)
+		return;
+
+	hci_send_acl(conn->hcon, skb, 0);
+}
+
+static __u8 seclevel_to_authreq(__u8 level)
+{
+	switch (level) {
+	case BT_SECURITY_HIGH:
+		/* Right now we don't support bonding */
+		return SMP_AUTH_MITM;
+
+	default:
+		return SMP_AUTH_NONE;
+	}
+}
+
+static void build_pairing_cmd(struct l2cap_conn *conn,
+				struct smp_cmd_pairing *cmd, __u8 authreq)
+{
+	cmd->io_capability = conn->hcon->io_capability;
+	cmd->oob_flag = SMP_OOB_NOT_PRESENT;
+	cmd->max_key_size = SMP_MAX_ENC_KEY_SIZE;
+	cmd->init_key_dist = 0x00;
+	cmd->resp_key_dist = 0x00;
+	cmd->auth_req = authreq;
+}
+
+static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size)
+{
+	if ((max_key_size > SMP_MAX_ENC_KEY_SIZE) ||
+			(max_key_size < SMP_MIN_ENC_KEY_SIZE))
+		return SMP_ENC_KEY_SIZE;
+
+	conn->smp_key_size = max_key_size;
+
+	return 0;
+}
+
+static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	struct smp_cmd_pairing rsp, *req = (void *) skb->data;
+	u8 key_size;
+
+	BT_DBG("conn %p", conn);
+
+	conn->preq[0] = SMP_CMD_PAIRING_REQ;
+	memcpy(&conn->preq[1], req, sizeof(*req));
+	skb_pull(skb, sizeof(*req));
+
+	if (req->oob_flag)
+		return SMP_OOB_NOT_AVAIL;
+
+	/* We didn't start the pairing, so no requirements */
+	build_pairing_cmd(conn, &rsp, SMP_AUTH_NONE);
+
+	key_size = min(req->max_key_size, rsp.max_key_size);
+	if (check_enc_key_size(conn, key_size))
+		return SMP_ENC_KEY_SIZE;
+
+	/* Just works */
+	memset(conn->tk, 0, sizeof(conn->tk));
+
+	conn->prsp[0] = SMP_CMD_PAIRING_RSP;
+	memcpy(&conn->prsp[1], &rsp, sizeof(rsp));
+
+	smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp);
+
+	mod_timer(&conn->security_timer, jiffies +
+					msecs_to_jiffies(SMP_TIMEOUT));
+
+	return 0;
+}
+
+static u8 smp_cmd_pairing_rsp(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	struct smp_cmd_pairing *req, *rsp = (void *) skb->data;
+	struct smp_cmd_pairing_confirm cp;
+	struct crypto_blkcipher *tfm = conn->hcon->hdev->tfm;
+	int ret;
+	u8 res[16], key_size;
+
+	BT_DBG("conn %p", conn);
+
+	skb_pull(skb, sizeof(*rsp));
+
+	req = (void *) &conn->preq[1];
+
+	key_size = min(req->max_key_size, rsp->max_key_size);
+	if (check_enc_key_size(conn, key_size))
+		return SMP_ENC_KEY_SIZE;
+
+	if (rsp->oob_flag)
+		return SMP_OOB_NOT_AVAIL;
+
+	/* Just works */
+	memset(conn->tk, 0, sizeof(conn->tk));
+
+	conn->prsp[0] = SMP_CMD_PAIRING_RSP;
+	memcpy(&conn->prsp[1], rsp, sizeof(*rsp));
+
+	ret = smp_rand(conn->prnd);
+	if (ret)
+		return SMP_UNSPECIFIED;
+
+	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 SMP_UNSPECIFIED;
+
+	swap128(res, cp.confirm_val);
+
+	smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
+
+	return 0;
+}
+
+static u8 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");
+
+	memcpy(conn->pcnf, skb->data, sizeof(conn->pcnf));
+	skb_pull(skb, sizeof(conn->pcnf));
+
+	if (conn->hcon->out) {
+		u8 random[16];
+
+		swap128(conn->prnd, random);
+		smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(random),
+								random);
+	} else {
+		struct smp_cmd_pairing_confirm cp;
+		int ret;
+		u8 res[16];
+
+		ret = smp_rand(conn->prnd);
+		if (ret)
+			return SMP_UNSPECIFIED;
+
+		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 SMP_CONFIRM_FAILED;
+
+		swap128(res, cp.confirm_val);
+
+		smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp);
+	}
+
+	mod_timer(&conn->security_timer, jiffies +
+					msecs_to_jiffies(SMP_TIMEOUT));
+
+	return 0;
+}
+
+static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	struct hci_conn *hcon = conn->hcon;
+	struct crypto_blkcipher *tfm = hcon->hdev->tfm;
+	int ret;
+	u8 key[16], res[16], random[16], confirm[16];
+
+	swap128(skb->data, random);
+	skb_pull(skb, sizeof(random));
+
+	memset(hcon->ltk, 0, sizeof(hcon->ltk));
+
+	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 SMP_UNSPECIFIED;
+
+	BT_DBG("conn %p %s", conn, conn->hcon->out ? "master" : "slave");
+
+	swap128(res, confirm);
+
+	if (memcmp(conn->pcnf, confirm, sizeof(conn->pcnf)) != 0) {
+		BT_ERR("Pairing failed (confirmation values mismatch)");
+		return SMP_CONFIRM_FAILED;
+	}
+
+	if (conn->hcon->out) {
+		__le16 ediv;
+		u8 rand[8];
+
+		smp_s1(tfm, conn->tk, random, conn->prnd, key);
+		swap128(key, hcon->ltk);
+
+		memset(hcon->ltk + conn->smp_key_size, 0,
+				SMP_MAX_ENC_KEY_SIZE - conn->smp_key_size);
+
+		memset(rand, 0, sizeof(rand));
+		ediv = 0;
+		hci_le_start_enc(hcon, ediv, rand, hcon->ltk);
+	} else {
+		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);
+		swap128(key, hcon->ltk);
+
+		memset(hcon->ltk + conn->smp_key_size, 0,
+				SMP_MAX_ENC_KEY_SIZE - conn->smp_key_size);
+	}
+
+	return 0;
+}
+
+static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	struct smp_cmd_security_req *rp = (void *) skb->data;
+	struct smp_cmd_pairing cp;
+	struct hci_conn *hcon = conn->hcon;
+
+	BT_DBG("conn %p", conn);
+
+	if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
+		return 0;
+
+	skb_pull(skb, sizeof(*rp));
+
+	memset(&cp, 0, sizeof(cp));
+	build_pairing_cmd(conn, &cp, rp->auth_req);
+
+	conn->preq[0] = SMP_CMD_PAIRING_REQ;
+	memcpy(&conn->preq[1], &cp, sizeof(cp));
+
+	smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
+
+	mod_timer(&conn->security_timer, jiffies +
+					msecs_to_jiffies(SMP_TIMEOUT));
+
+	set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend);
+
+	return 0;
+}
+
+int smp_conn_security(struct l2cap_conn *conn, __u8 sec_level)
+{
+	struct hci_conn *hcon = conn->hcon;
+	__u8 authreq;
+
+	BT_DBG("conn %p hcon %p level 0x%2.2x", conn, hcon, sec_level);
+
+	if (IS_ERR(hcon->hdev->tfm))
+		return 1;
+
+	if (test_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend))
+		return 0;
+
+	if (sec_level == BT_SECURITY_LOW)
+		return 1;
+
+	if (hcon->sec_level >= sec_level)
+		return 1;
+
+	authreq = seclevel_to_authreq(sec_level);
+
+	if (hcon->link_mode & HCI_LM_MASTER) {
+		struct smp_cmd_pairing cp;
+
+		build_pairing_cmd(conn, &cp, authreq);
+		conn->preq[0] = SMP_CMD_PAIRING_REQ;
+		memcpy(&conn->preq[1], &cp, sizeof(cp));
+
+		mod_timer(&conn->security_timer, jiffies +
+					msecs_to_jiffies(SMP_TIMEOUT));
+
+		smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp);
+	} else {
+		struct smp_cmd_security_req cp;
+		cp.auth_req = authreq;
+		smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp);
+	}
+
+	hcon->pending_sec_level = sec_level;
+	set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->pend);
+
+	return 0;
+}
+
+int smp_sig_channel(struct l2cap_conn *conn, struct sk_buff *skb)
+{
+	__u8 code = skb->data[0];
+	__u8 reason;
+	int err = 0;
+
+	if (IS_ERR(conn->hcon->hdev->tfm)) {
+		err = PTR_ERR(conn->hcon->hdev->tfm);
+		reason = SMP_PAIRING_NOTSUPP;
+		goto done;
+	}
+
+	skb_pull(skb, sizeof(code));
+
+	switch (code) {
+	case SMP_CMD_PAIRING_REQ:
+		reason = smp_cmd_pairing_req(conn, skb);
+		break;
+
+	case SMP_CMD_PAIRING_FAIL:
+		reason = 0;
+		err = -EPERM;
+		break;
+
+	case SMP_CMD_PAIRING_RSP:
+		reason = smp_cmd_pairing_rsp(conn, skb);
+		break;
+
+	case SMP_CMD_SECURITY_REQ:
+		reason = smp_cmd_security_req(conn, skb);
+		break;
+
+	case SMP_CMD_PAIRING_CONFIRM:
+		reason = smp_cmd_pairing_confirm(conn, skb);
+		break;
+
+	case SMP_CMD_PAIRING_RANDOM:
+		reason = smp_cmd_pairing_random(conn, skb);
+		break;
+
+	case SMP_CMD_ENCRYPT_INFO:
+	case SMP_CMD_MASTER_IDENT:
+	case SMP_CMD_IDENT_INFO:
+	case SMP_CMD_IDENT_ADDR_INFO:
+	case SMP_CMD_SIGN_INFO:
+	default:
+		BT_DBG("Unknown command code 0x%2.2x", code);
+
+		reason = SMP_CMD_NOTSUPP;
+		err = -EOPNOTSUPP;
+		goto done;
+	}
+
+done:
+	if (reason)
+		smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
+								&reason);
+
+	kfree_skb(skb);
+	return err;
+}