| /* |
| 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 <linux/debugfs.h> |
| #include <linux/scatterlist.h> |
| #include <linux/crypto.h> |
| #include <crypto/aes.h> |
| #include <crypto/algapi.h> |
| #include <crypto/hash.h> |
| #include <crypto/kpp.h> |
| |
| #include <net/bluetooth/bluetooth.h> |
| #include <net/bluetooth/hci_core.h> |
| #include <net/bluetooth/l2cap.h> |
| #include <net/bluetooth/mgmt.h> |
| |
| #include "ecdh_helper.h" |
| #include "smp.h" |
| |
| #define SMP_DEV(hdev) \ |
| ((struct smp_dev *)((struct l2cap_chan *)((hdev)->smp_data))->data) |
| |
| /* Low-level debug macros to be used for stuff that we don't want |
| * accidentally in dmesg, i.e. the values of the various crypto keys |
| * and the inputs & outputs of crypto functions. |
| */ |
| #ifdef DEBUG |
| #define SMP_DBG(fmt, ...) printk(KERN_DEBUG "%s: " fmt, __func__, \ |
| ##__VA_ARGS__) |
| #else |
| #define SMP_DBG(fmt, ...) no_printk(KERN_DEBUG "%s: " fmt, __func__, \ |
| ##__VA_ARGS__) |
| #endif |
| |
| #define SMP_ALLOW_CMD(smp, code) set_bit(code, &smp->allow_cmd) |
| |
| /* Keys which are not distributed with Secure Connections */ |
| #define SMP_SC_NO_DIST (SMP_DIST_ENC_KEY | SMP_DIST_LINK_KEY) |
| |
| #define SMP_TIMEOUT msecs_to_jiffies(30000) |
| |
| #define AUTH_REQ_MASK(dev) (hci_dev_test_flag(dev, HCI_SC_ENABLED) ? \ |
| 0x3f : 0x07) |
| #define KEY_DIST_MASK 0x07 |
| |
| /* Maximum message length that can be passed to aes_cmac */ |
| #define CMAC_MSG_MAX 80 |
| |
| enum { |
| SMP_FLAG_TK_VALID, |
| SMP_FLAG_CFM_PENDING, |
| SMP_FLAG_MITM_AUTH, |
| SMP_FLAG_COMPLETE, |
| SMP_FLAG_INITIATOR, |
| SMP_FLAG_SC, |
| SMP_FLAG_REMOTE_PK, |
| SMP_FLAG_DEBUG_KEY, |
| SMP_FLAG_WAIT_USER, |
| SMP_FLAG_DHKEY_PENDING, |
| SMP_FLAG_REMOTE_OOB, |
| SMP_FLAG_LOCAL_OOB, |
| SMP_FLAG_CT2, |
| }; |
| |
| struct smp_dev { |
| /* Secure Connections OOB data */ |
| bool local_oob; |
| u8 local_pk[64]; |
| u8 local_rand[16]; |
| bool debug_key; |
| |
| struct crypto_shash *tfm_cmac; |
| struct crypto_kpp *tfm_ecdh; |
| }; |
| |
| struct smp_chan { |
| struct l2cap_conn *conn; |
| struct delayed_work security_timer; |
| unsigned long allow_cmd; /* Bitmask of allowed commands */ |
| |
| u8 preq[7]; /* SMP Pairing Request */ |
| u8 prsp[7]; /* SMP Pairing Response */ |
| u8 prnd[16]; /* SMP Pairing Random (local) */ |
| u8 rrnd[16]; /* SMP Pairing Random (remote) */ |
| u8 pcnf[16]; /* SMP Pairing Confirm */ |
| u8 tk[16]; /* SMP Temporary Key */ |
| u8 rr[16]; /* Remote OOB ra/rb value */ |
| u8 lr[16]; /* Local OOB ra/rb value */ |
| u8 enc_key_size; |
| u8 remote_key_dist; |
| bdaddr_t id_addr; |
| u8 id_addr_type; |
| u8 irk[16]; |
| struct smp_csrk *csrk; |
| struct smp_csrk *responder_csrk; |
| struct smp_ltk *ltk; |
| struct smp_ltk *responder_ltk; |
| struct smp_irk *remote_irk; |
| u8 *link_key; |
| unsigned long flags; |
| u8 method; |
| u8 passkey_round; |
| |
| /* Secure Connections variables */ |
| u8 local_pk[64]; |
| u8 remote_pk[64]; |
| u8 dhkey[32]; |
| u8 mackey[16]; |
| |
| struct crypto_shash *tfm_cmac; |
| struct crypto_kpp *tfm_ecdh; |
| }; |
| |
| /* These debug key values are defined in the SMP section of the core |
| * specification. debug_pk is the public debug key and debug_sk the |
| * private debug key. |
| */ |
| static const u8 debug_pk[64] = { |
| 0xe6, 0x9d, 0x35, 0x0e, 0x48, 0x01, 0x03, 0xcc, |
| 0xdb, 0xfd, 0xf4, 0xac, 0x11, 0x91, 0xf4, 0xef, |
| 0xb9, 0xa5, 0xf9, 0xe9, 0xa7, 0x83, 0x2c, 0x5e, |
| 0x2c, 0xbe, 0x97, 0xf2, 0xd2, 0x03, 0xb0, 0x20, |
| |
| 0x8b, 0xd2, 0x89, 0x15, 0xd0, 0x8e, 0x1c, 0x74, |
| 0x24, 0x30, 0xed, 0x8f, 0xc2, 0x45, 0x63, 0x76, |
| 0x5c, 0x15, 0x52, 0x5a, 0xbf, 0x9a, 0x32, 0x63, |
| 0x6d, 0xeb, 0x2a, 0x65, 0x49, 0x9c, 0x80, 0xdc, |
| }; |
| |
| static const u8 debug_sk[32] = { |
| 0xbd, 0x1a, 0x3c, 0xcd, 0xa6, 0xb8, 0x99, 0x58, |
| 0x99, 0xb7, 0x40, 0xeb, 0x7b, 0x60, 0xff, 0x4a, |
| 0x50, 0x3f, 0x10, 0xd2, 0xe3, 0xb3, 0xc9, 0x74, |
| 0x38, 0x5f, 0xc5, 0xa3, 0xd4, 0xf6, 0x49, 0x3f, |
| }; |
| |
| static inline void swap_buf(const u8 *src, u8 *dst, size_t len) |
| { |
| size_t i; |
| |
| for (i = 0; i < len; i++) |
| dst[len - 1 - i] = src[i]; |
| } |
| |
| /* The following functions map to the LE SC SMP crypto functions |
| * AES-CMAC, f4, f5, f6, g2 and h6. |
| */ |
| |
| static int aes_cmac(struct crypto_shash *tfm, const u8 k[16], const u8 *m, |
| size_t len, u8 mac[16]) |
| { |
| uint8_t tmp[16], mac_msb[16], msg_msb[CMAC_MSG_MAX]; |
| int err; |
| |
| if (len > CMAC_MSG_MAX) |
| return -EFBIG; |
| |
| if (!tfm) { |
| BT_ERR("tfm %p", tfm); |
| return -EINVAL; |
| } |
| |
| /* Swap key and message from LSB to MSB */ |
| swap_buf(k, tmp, 16); |
| swap_buf(m, msg_msb, len); |
| |
| SMP_DBG("msg (len %zu) %*phN", len, (int) len, m); |
| SMP_DBG("key %16phN", k); |
| |
| err = crypto_shash_setkey(tfm, tmp, 16); |
| if (err) { |
| BT_ERR("cipher setkey failed: %d", err); |
| return err; |
| } |
| |
| err = crypto_shash_tfm_digest(tfm, msg_msb, len, mac_msb); |
| if (err) { |
| BT_ERR("Hash computation error %d", err); |
| return err; |
| } |
| |
| swap_buf(mac_msb, mac, 16); |
| |
| SMP_DBG("mac %16phN", mac); |
| |
| return 0; |
| } |
| |
| static int smp_f4(struct crypto_shash *tfm_cmac, const u8 u[32], |
| const u8 v[32], const u8 x[16], u8 z, u8 res[16]) |
| { |
| u8 m[65]; |
| int err; |
| |
| SMP_DBG("u %32phN", u); |
| SMP_DBG("v %32phN", v); |
| SMP_DBG("x %16phN z %02x", x, z); |
| |
| m[0] = z; |
| memcpy(m + 1, v, 32); |
| memcpy(m + 33, u, 32); |
| |
| err = aes_cmac(tfm_cmac, x, m, sizeof(m), res); |
| if (err) |
| return err; |
| |
| SMP_DBG("res %16phN", res); |
| |
| return err; |
| } |
| |
| static int smp_f5(struct crypto_shash *tfm_cmac, const u8 w[32], |
| const u8 n1[16], const u8 n2[16], const u8 a1[7], |
| const 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; |
| |
| SMP_DBG("w %32phN", w); |
| SMP_DBG("n1 %16phN n2 %16phN", n1, n2); |
| SMP_DBG("a1 %7phN a2 %7phN", a1, a2); |
| |
| err = aes_cmac(tfm_cmac, salt, w, 32, t); |
| if (err) |
| return err; |
| |
| SMP_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; |
| |
| SMP_DBG("mackey %16phN", mackey); |
| |
| m[52] = 1; /* Counter */ |
| |
| err = aes_cmac(tfm_cmac, t, m, sizeof(m), ltk); |
| if (err) |
| return err; |
| |
| SMP_DBG("ltk %16phN", ltk); |
| |
| return 0; |
| } |
| |
| static int smp_f6(struct crypto_shash *tfm_cmac, const u8 w[16], |
| const u8 n1[16], const 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; |
| |
| SMP_DBG("w %16phN", w); |
| SMP_DBG("n1 %16phN n2 %16phN", n1, n2); |
| SMP_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; |
| |
| SMP_DBG("res %16phN", res); |
| |
| return err; |
| } |
| |
| static int smp_g2(struct crypto_shash *tfm_cmac, const u8 u[32], const u8 v[32], |
| const u8 x[16], const u8 y[16], u32 *val) |
| { |
| u8 m[80], tmp[16]; |
| int err; |
| |
| SMP_DBG("u %32phN", u); |
| SMP_DBG("v %32phN", v); |
| SMP_DBG("x %16phN y %16phN", x, y); |
| |
| memcpy(m, y, 16); |
| memcpy(m + 16, v, 32); |
| memcpy(m + 48, u, 32); |
| |
| err = aes_cmac(tfm_cmac, x, m, sizeof(m), tmp); |
| if (err) |
| return err; |
| |
| *val = get_unaligned_le32(tmp); |
| *val %= 1000000; |
| |
| SMP_DBG("val %06u", *val); |
| |
| return 0; |
| } |
| |
| static int smp_h6(struct crypto_shash *tfm_cmac, const u8 w[16], |
| const u8 key_id[4], u8 res[16]) |
| { |
| int err; |
| |
| SMP_DBG("w %16phN key_id %4phN", w, key_id); |
| |
| err = aes_cmac(tfm_cmac, w, key_id, 4, res); |
| if (err) |
| return err; |
| |
| SMP_DBG("res %16phN", res); |
| |
| return err; |
| } |
| |
| static int smp_h7(struct crypto_shash *tfm_cmac, const u8 w[16], |
| const u8 salt[16], u8 res[16]) |
| { |
| int err; |
| |
| SMP_DBG("w %16phN salt %16phN", w, salt); |
| |
| err = aes_cmac(tfm_cmac, salt, w, 16, res); |
| if (err) |
| return err; |
| |
| SMP_DBG("res %16phN", res); |
| |
| return err; |
| } |
| |
| /* The following functions map to the legacy SMP crypto functions e, c1, |
| * s1 and ah. |
| */ |
| |
| static int smp_e(const u8 *k, u8 *r) |
| { |
| struct crypto_aes_ctx ctx; |
| uint8_t tmp[16], data[16]; |
| int err; |
| |
| SMP_DBG("k %16phN r %16phN", k, r); |
| |
| /* The most significant octet of key corresponds to k[0] */ |
| swap_buf(k, tmp, 16); |
| |
| err = aes_expandkey(&ctx, tmp, 16); |
| if (err) { |
| BT_ERR("cipher setkey failed: %d", err); |
| return err; |
| } |
| |
| /* Most significant octet of plaintextData corresponds to data[0] */ |
| swap_buf(r, data, 16); |
| |
| aes_encrypt(&ctx, data, data); |
| |
| /* Most significant octet of encryptedData corresponds to data[0] */ |
| swap_buf(data, r, 16); |
| |
| SMP_DBG("r %16phN", r); |
| |
| memzero_explicit(&ctx, sizeof(ctx)); |
| return err; |
| } |
| |
| static int smp_c1(const u8 k[16], |
| const u8 r[16], const u8 preq[7], const u8 pres[7], u8 _iat, |
| const bdaddr_t *ia, u8 _rat, const bdaddr_t *ra, u8 res[16]) |
| { |
| u8 p1[16], p2[16]; |
| int err; |
| |
| SMP_DBG("k %16phN r %16phN", k, r); |
| SMP_DBG("iat %u ia %6phN rat %u ra %6phN", _iat, ia, _rat, ra); |
| SMP_DBG("preq %7phN pres %7phN", preq, pres); |
| |
| memset(p1, 0, 16); |
| |
| /* p1 = pres || preq || _rat || _iat */ |
| p1[0] = _iat; |
| p1[1] = _rat; |
| memcpy(p1 + 2, preq, 7); |
| memcpy(p1 + 9, pres, 7); |
| |
| SMP_DBG("p1 %16phN", p1); |
| |
| /* res = r XOR p1 */ |
| crypto_xor_cpy(res, r, p1, sizeof(p1)); |
| |
| /* res = e(k, res) */ |
| err = smp_e(k, res); |
| if (err) { |
| BT_ERR("Encrypt data error"); |
| return err; |
| } |
| |
| /* p2 = padding || ia || ra */ |
| memcpy(p2, ra, 6); |
| memcpy(p2 + 6, ia, 6); |
| memset(p2 + 12, 0, 4); |
| |
| SMP_DBG("p2 %16phN", p2); |
| |
| /* res = res XOR p2 */ |
| crypto_xor(res, p2, sizeof(p2)); |
| |
| /* res = e(k, res) */ |
| err = smp_e(k, res); |
| if (err) |
| BT_ERR("Encrypt data error"); |
| |
| return err; |
| } |
| |
| static int smp_s1(const u8 k[16], |
| const u8 r1[16], const u8 r2[16], u8 _r[16]) |
| { |
| int err; |
| |
| /* Just least significant octets from r1 and r2 are considered */ |
| memcpy(_r, r2, 8); |
| memcpy(_r + 8, r1, 8); |
| |
| err = smp_e(k, _r); |
| if (err) |
| BT_ERR("Encrypt data error"); |
| |
| return err; |
| } |
| |
| static int smp_ah(const u8 irk[16], const u8 r[3], u8 res[3]) |
| { |
| u8 _res[16]; |
| int err; |
| |
| /* r' = padding || r */ |
| memcpy(_res, r, 3); |
| memset(_res + 3, 0, 13); |
| |
| err = smp_e(irk, _res); |
| if (err) { |
| BT_ERR("Encrypt error"); |
| return err; |
| } |
| |
| /* The output of the random address function ah is: |
| * ah(k, 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. |
| */ |
| memcpy(res, _res, 3); |
| |
| return 0; |
| } |
| |
| bool smp_irk_matches(struct hci_dev *hdev, const u8 irk[16], |
| const bdaddr_t *bdaddr) |
| { |
| struct l2cap_chan *chan = hdev->smp_data; |
| u8 hash[3]; |
| int err; |
| |
| if (!chan || !chan->data) |
| return false; |
| |
| bt_dev_dbg(hdev, "RPA %pMR IRK %*phN", bdaddr, 16, irk); |
| |
| err = smp_ah(irk, &bdaddr->b[3], hash); |
| if (err) |
| return false; |
| |
| return !crypto_memneq(bdaddr->b, hash, 3); |
| } |
| |
| int smp_generate_rpa(struct hci_dev *hdev, const u8 irk[16], bdaddr_t *rpa) |
| { |
| struct l2cap_chan *chan = hdev->smp_data; |
| int err; |
| |
| if (!chan || !chan->data) |
| return -EOPNOTSUPP; |
| |
| get_random_bytes(&rpa->b[3], 3); |
| |
| rpa->b[5] &= 0x3f; /* Clear two most significant bits */ |
| rpa->b[5] |= 0x40; /* Set second most significant bit */ |
| |
| err = smp_ah(irk, &rpa->b[3], rpa->b); |
| if (err < 0) |
| return err; |
| |
| bt_dev_dbg(hdev, "RPA %pMR", rpa); |
| |
| return 0; |
| } |
| |
| int smp_generate_oob(struct hci_dev *hdev, u8 hash[16], u8 rand[16]) |
| { |
| struct l2cap_chan *chan = hdev->smp_data; |
| struct smp_dev *smp; |
| int err; |
| |
| if (!chan || !chan->data) |
| return -EOPNOTSUPP; |
| |
| smp = chan->data; |
| |
| if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { |
| bt_dev_dbg(hdev, "Using debug keys"); |
| err = set_ecdh_privkey(smp->tfm_ecdh, debug_sk); |
| if (err) |
| return err; |
| memcpy(smp->local_pk, debug_pk, 64); |
| smp->debug_key = true; |
| } else { |
| while (true) { |
| /* Generate key pair for Secure Connections */ |
| err = generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk); |
| if (err) |
| return err; |
| |
| /* This is unlikely, but we need to check that |
| * we didn't accidentally generate a debug key. |
| */ |
| if (crypto_memneq(smp->local_pk, debug_pk, 64)) |
| break; |
| } |
| smp->debug_key = false; |
| } |
| |
| SMP_DBG("OOB Public Key X: %32phN", smp->local_pk); |
| SMP_DBG("OOB Public Key Y: %32phN", smp->local_pk + 32); |
| |
| get_random_bytes(smp->local_rand, 16); |
| |
| err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->local_pk, |
| smp->local_rand, 0, hash); |
| if (err < 0) |
| return err; |
| |
| memcpy(rand, smp->local_rand, 16); |
| |
| smp->local_oob = true; |
| |
| return 0; |
| } |
| |
| static void smp_send_cmd(struct l2cap_conn *conn, u8 code, u16 len, void *data) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp; |
| struct kvec iv[2]; |
| struct msghdr msg; |
| |
| if (!chan) |
| return; |
| |
| bt_dev_dbg(conn->hcon->hdev, "code 0x%2.2x", code); |
| |
| iv[0].iov_base = &code; |
| iv[0].iov_len = 1; |
| |
| iv[1].iov_base = data; |
| iv[1].iov_len = len; |
| |
| memset(&msg, 0, sizeof(msg)); |
| |
| iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, iv, 2, 1 + len); |
| |
| l2cap_chan_send(chan, &msg, 1 + len); |
| |
| if (!chan->data) |
| return; |
| |
| smp = chan->data; |
| |
| cancel_delayed_work_sync(&smp->security_timer); |
| schedule_delayed_work(&smp->security_timer, SMP_TIMEOUT); |
| } |
| |
| static u8 authreq_to_seclevel(u8 authreq) |
| { |
| if (authreq & SMP_AUTH_MITM) { |
| if (authreq & SMP_AUTH_SC) |
| return BT_SECURITY_FIPS; |
| else |
| return BT_SECURITY_HIGH; |
| } else { |
| return BT_SECURITY_MEDIUM; |
| } |
| } |
| |
| static __u8 seclevel_to_authreq(__u8 sec_level) |
| { |
| switch (sec_level) { |
| case BT_SECURITY_FIPS: |
| case BT_SECURITY_HIGH: |
| return SMP_AUTH_MITM | SMP_AUTH_BONDING; |
| case BT_SECURITY_MEDIUM: |
| return SMP_AUTH_BONDING; |
| default: |
| return SMP_AUTH_NONE; |
| } |
| } |
| |
| static void build_pairing_cmd(struct l2cap_conn *conn, |
| struct smp_cmd_pairing *req, |
| struct smp_cmd_pairing *rsp, __u8 authreq) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| u8 local_dist = 0, remote_dist = 0, oob_flag = SMP_OOB_NOT_PRESENT; |
| |
| if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { |
| local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; |
| remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; |
| authreq |= SMP_AUTH_BONDING; |
| } else { |
| authreq &= ~SMP_AUTH_BONDING; |
| } |
| |
| if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) |
| remote_dist |= SMP_DIST_ID_KEY; |
| |
| if (hci_dev_test_flag(hdev, HCI_PRIVACY)) |
| local_dist |= SMP_DIST_ID_KEY; |
| |
| if (hci_dev_test_flag(hdev, HCI_SC_ENABLED) && |
| (authreq & SMP_AUTH_SC)) { |
| struct oob_data *oob_data; |
| u8 bdaddr_type; |
| |
| if (hci_dev_test_flag(hdev, HCI_SSP_ENABLED)) { |
| local_dist |= SMP_DIST_LINK_KEY; |
| remote_dist |= SMP_DIST_LINK_KEY; |
| } |
| |
| if (hcon->dst_type == ADDR_LE_DEV_PUBLIC) |
| bdaddr_type = BDADDR_LE_PUBLIC; |
| else |
| bdaddr_type = BDADDR_LE_RANDOM; |
| |
| oob_data = hci_find_remote_oob_data(hdev, &hcon->dst, |
| bdaddr_type); |
| if (oob_data && oob_data->present) { |
| set_bit(SMP_FLAG_REMOTE_OOB, &smp->flags); |
| 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 { |
| authreq &= ~SMP_AUTH_SC; |
| } |
| |
| if (rsp == NULL) { |
| req->io_capability = conn->hcon->io_capability; |
| req->oob_flag = oob_flag; |
| req->max_key_size = hdev->le_max_key_size; |
| req->init_key_dist = local_dist; |
| req->resp_key_dist = remote_dist; |
| req->auth_req = (authreq & AUTH_REQ_MASK(hdev)); |
| |
| smp->remote_key_dist = remote_dist; |
| return; |
| } |
| |
| rsp->io_capability = conn->hcon->io_capability; |
| rsp->oob_flag = oob_flag; |
| rsp->max_key_size = hdev->le_max_key_size; |
| rsp->init_key_dist = req->init_key_dist & remote_dist; |
| rsp->resp_key_dist = req->resp_key_dist & local_dist; |
| rsp->auth_req = (authreq & AUTH_REQ_MASK(hdev)); |
| |
| smp->remote_key_dist = rsp->init_key_dist; |
| } |
| |
| static u8 check_enc_key_size(struct l2cap_conn *conn, __u8 max_key_size) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct hci_dev *hdev = conn->hcon->hdev; |
| struct smp_chan *smp = chan->data; |
| |
| if (conn->hcon->pending_sec_level == BT_SECURITY_FIPS && |
| max_key_size != SMP_MAX_ENC_KEY_SIZE) |
| return SMP_ENC_KEY_SIZE; |
| |
| if (max_key_size > hdev->le_max_key_size || |
| max_key_size < SMP_MIN_ENC_KEY_SIZE) |
| return SMP_ENC_KEY_SIZE; |
| |
| smp->enc_key_size = max_key_size; |
| |
| return 0; |
| } |
| |
| static void smp_chan_destroy(struct l2cap_conn *conn) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| bool complete; |
| |
| BUG_ON(!smp); |
| |
| cancel_delayed_work_sync(&smp->security_timer); |
| |
| complete = test_bit(SMP_FLAG_COMPLETE, &smp->flags); |
| mgmt_smp_complete(hcon, complete); |
| |
| kfree_sensitive(smp->csrk); |
| kfree_sensitive(smp->responder_csrk); |
| kfree_sensitive(smp->link_key); |
| |
| crypto_free_shash(smp->tfm_cmac); |
| crypto_free_kpp(smp->tfm_ecdh); |
| |
| /* Ensure that we don't leave any debug key around if debug key |
| * support hasn't been explicitly enabled. |
| */ |
| if (smp->ltk && smp->ltk->type == SMP_LTK_P256_DEBUG && |
| !hci_dev_test_flag(hcon->hdev, HCI_KEEP_DEBUG_KEYS)) { |
| list_del_rcu(&smp->ltk->list); |
| kfree_rcu(smp->ltk, rcu); |
| smp->ltk = NULL; |
| } |
| |
| /* If pairing failed clean up any keys we might have */ |
| if (!complete) { |
| if (smp->ltk) { |
| list_del_rcu(&smp->ltk->list); |
| kfree_rcu(smp->ltk, rcu); |
| } |
| |
| if (smp->responder_ltk) { |
| list_del_rcu(&smp->responder_ltk->list); |
| kfree_rcu(smp->responder_ltk, rcu); |
| } |
| |
| if (smp->remote_irk) { |
| list_del_rcu(&smp->remote_irk->list); |
| kfree_rcu(smp->remote_irk, rcu); |
| } |
| } |
| |
| chan->data = NULL; |
| kfree_sensitive(smp); |
| hci_conn_drop(hcon); |
| } |
| |
| static void smp_failure(struct l2cap_conn *conn, u8 reason) |
| { |
| struct hci_conn *hcon = conn->hcon; |
| struct l2cap_chan *chan = conn->smp; |
| |
| if (reason) |
| smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason), |
| &reason); |
| |
| mgmt_auth_failed(hcon, HCI_ERROR_AUTH_FAILURE); |
| |
| if (chan->data) |
| smp_chan_destroy(conn); |
| } |
| |
| #define JUST_WORKS 0x00 |
| #define JUST_CFM 0x01 |
| #define REQ_PASSKEY 0x02 |
| #define CFM_PASSKEY 0x03 |
| #define REQ_OOB 0x04 |
| #define DSP_PASSKEY 0x05 |
| #define OVERLAP 0xFF |
| |
| static const u8 gen_method[5][5] = { |
| { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, |
| { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, |
| { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, |
| { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, |
| { CFM_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, OVERLAP }, |
| }; |
| |
| static const u8 sc_method[5][5] = { |
| { JUST_WORKS, JUST_CFM, REQ_PASSKEY, JUST_WORKS, REQ_PASSKEY }, |
| { JUST_WORKS, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, |
| { DSP_PASSKEY, DSP_PASSKEY, REQ_PASSKEY, JUST_WORKS, DSP_PASSKEY }, |
| { JUST_WORKS, JUST_CFM, JUST_WORKS, JUST_WORKS, JUST_CFM }, |
| { DSP_PASSKEY, CFM_PASSKEY, REQ_PASSKEY, JUST_WORKS, CFM_PASSKEY }, |
| }; |
| |
| static u8 get_auth_method(struct smp_chan *smp, u8 local_io, u8 remote_io) |
| { |
| /* If either side has unknown io_caps, use JUST_CFM (which gets |
| * converted later to JUST_WORKS if we're initiators. |
| */ |
| if (local_io > SMP_IO_KEYBOARD_DISPLAY || |
| remote_io > SMP_IO_KEYBOARD_DISPLAY) |
| return JUST_CFM; |
| |
| if (test_bit(SMP_FLAG_SC, &smp->flags)) |
| return sc_method[remote_io][local_io]; |
| |
| return gen_method[remote_io][local_io]; |
| } |
| |
| static int tk_request(struct l2cap_conn *conn, u8 remote_oob, u8 auth, |
| u8 local_io, u8 remote_io) |
| { |
| struct hci_conn *hcon = conn->hcon; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| u32 passkey = 0; |
| int ret; |
| |
| /* Initialize key for JUST WORKS */ |
| memset(smp->tk, 0, sizeof(smp->tk)); |
| clear_bit(SMP_FLAG_TK_VALID, &smp->flags); |
| |
| bt_dev_dbg(hcon->hdev, "auth:%u lcl:%u rem:%u", auth, local_io, |
| remote_io); |
| |
| /* If neither side wants MITM, either "just" confirm an incoming |
| * request or use just-works for outgoing ones. The JUST_CFM |
| * will be converted to JUST_WORKS if necessary later in this |
| * function. If either side has MITM look up the method from the |
| * table. |
| */ |
| if (!(auth & SMP_AUTH_MITM)) |
| smp->method = JUST_CFM; |
| else |
| smp->method = get_auth_method(smp, local_io, remote_io); |
| |
| /* Don't confirm locally initiated pairing attempts */ |
| if (smp->method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, |
| &smp->flags)) |
| smp->method = JUST_WORKS; |
| |
| /* Don't bother user space with no IO capabilities */ |
| if (smp->method == JUST_CFM && |
| hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) |
| smp->method = JUST_WORKS; |
| |
| /* If Just Works, Continue with Zero TK and ask user-space for |
| * confirmation */ |
| if (smp->method == JUST_WORKS) { |
| ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, |
| hcon->type, |
| hcon->dst_type, |
| passkey, 1); |
| if (ret) |
| return ret; |
| set_bit(SMP_FLAG_WAIT_USER, &smp->flags); |
| 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); |
| if (hcon->pending_sec_level < BT_SECURITY_HIGH) |
| hcon->pending_sec_level = BT_SECURITY_HIGH; |
| } |
| |
| /* If both devices have Keyboard-Display I/O, the initiator |
| * Confirms and the responder Enters the passkey. |
| */ |
| if (smp->method == OVERLAP) { |
| if (hcon->role == HCI_ROLE_MASTER) |
| smp->method = CFM_PASSKEY; |
| else |
| smp->method = REQ_PASSKEY; |
| } |
| |
| /* Generate random passkey. */ |
| if (smp->method == CFM_PASSKEY) { |
| memset(smp->tk, 0, sizeof(smp->tk)); |
| get_random_bytes(&passkey, sizeof(passkey)); |
| passkey %= 1000000; |
| put_unaligned_le32(passkey, smp->tk); |
| bt_dev_dbg(hcon->hdev, "PassKey: %u", passkey); |
| set_bit(SMP_FLAG_TK_VALID, &smp->flags); |
| } |
| |
| if (smp->method == REQ_PASSKEY) |
| ret = mgmt_user_passkey_request(hcon->hdev, &hcon->dst, |
| hcon->type, hcon->dst_type); |
| else if (smp->method == JUST_CFM) |
| ret = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, |
| hcon->type, hcon->dst_type, |
| passkey, 1); |
| else |
| ret = mgmt_user_passkey_notify(hcon->hdev, &hcon->dst, |
| hcon->type, hcon->dst_type, |
| passkey, 0); |
| |
| return ret; |
| } |
| |
| static u8 smp_confirm(struct smp_chan *smp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct smp_cmd_pairing_confirm cp; |
| int ret; |
| |
| bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); |
| |
| ret = smp_c1(smp->tk, smp->prnd, smp->preq, smp->prsp, |
| conn->hcon->init_addr_type, &conn->hcon->init_addr, |
| conn->hcon->resp_addr_type, &conn->hcon->resp_addr, |
| cp.confirm_val); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags); |
| |
| smp_send_cmd(smp->conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cp), &cp); |
| |
| if (conn->hcon->out) |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| else |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| |
| return 0; |
| } |
| |
| static u8 smp_random(struct smp_chan *smp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| u8 confirm[16]; |
| int ret; |
| |
| bt_dev_dbg(conn->hcon->hdev, "conn %p %s", conn, |
| conn->hcon->out ? "initiator" : "responder"); |
| |
| ret = smp_c1(smp->tk, smp->rrnd, smp->preq, smp->prsp, |
| hcon->init_addr_type, &hcon->init_addr, |
| hcon->resp_addr_type, &hcon->resp_addr, confirm); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| if (crypto_memneq(smp->pcnf, confirm, sizeof(smp->pcnf))) { |
| bt_dev_err(hcon->hdev, "pairing failed " |
| "(confirmation values mismatch)"); |
| return SMP_CONFIRM_FAILED; |
| } |
| |
| if (hcon->out) { |
| u8 stk[16]; |
| __le64 rand = 0; |
| __le16 ediv = 0; |
| |
| smp_s1(smp->tk, smp->rrnd, smp->prnd, stk); |
| |
| if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) |
| return SMP_UNSPECIFIED; |
| |
| hci_le_start_enc(hcon, ediv, rand, stk, smp->enc_key_size); |
| hcon->enc_key_size = smp->enc_key_size; |
| set_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); |
| } else { |
| u8 stk[16], auth; |
| __le64 rand = 0; |
| __le16 ediv = 0; |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), |
| smp->prnd); |
| |
| smp_s1(smp->tk, smp->prnd, smp->rrnd, stk); |
| |
| if (hcon->pending_sec_level == BT_SECURITY_HIGH) |
| auth = 1; |
| else |
| auth = 0; |
| |
| /* Even though there's no _RESPONDER suffix this is the |
| * responder STK we're adding for later lookup (the initiator |
| * STK never needs to be stored). |
| */ |
| hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, |
| SMP_STK, auth, stk, smp->enc_key_size, ediv, rand); |
| } |
| |
| return 0; |
| } |
| |
| static void smp_notify_keys(struct l2cap_conn *conn) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| struct smp_cmd_pairing *req = (void *) &smp->preq[1]; |
| struct smp_cmd_pairing *rsp = (void *) &smp->prsp[1]; |
| bool persistent; |
| |
| if (hcon->type == ACL_LINK) { |
| if (hcon->key_type == HCI_LK_DEBUG_COMBINATION) |
| persistent = false; |
| else |
| persistent = !test_bit(HCI_CONN_FLUSH_KEY, |
| &hcon->flags); |
| } else { |
| /* The LTKs, IRKs and CSRKs should be persistent only if |
| * both sides had the bonding bit set in their |
| * authentication requests. |
| */ |
| persistent = !!((req->auth_req & rsp->auth_req) & |
| SMP_AUTH_BONDING); |
| } |
| |
| if (smp->remote_irk) { |
| mgmt_new_irk(hdev, smp->remote_irk, persistent); |
| |
| /* Now that user space can be considered to know the |
| * identity address track the connection based on it |
| * from now on (assuming this is an LE link). |
| */ |
| if (hcon->type == LE_LINK) { |
| bacpy(&hcon->dst, &smp->remote_irk->bdaddr); |
| hcon->dst_type = smp->remote_irk->addr_type; |
| queue_work(hdev->workqueue, &conn->id_addr_update_work); |
| } |
| } |
| |
| if (smp->csrk) { |
| smp->csrk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->csrk->bdaddr, &hcon->dst); |
| mgmt_new_csrk(hdev, smp->csrk, persistent); |
| } |
| |
| if (smp->responder_csrk) { |
| smp->responder_csrk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->responder_csrk->bdaddr, &hcon->dst); |
| mgmt_new_csrk(hdev, smp->responder_csrk, persistent); |
| } |
| |
| if (smp->ltk) { |
| smp->ltk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->ltk->bdaddr, &hcon->dst); |
| mgmt_new_ltk(hdev, smp->ltk, persistent); |
| } |
| |
| if (smp->responder_ltk) { |
| smp->responder_ltk->bdaddr_type = hcon->dst_type; |
| bacpy(&smp->responder_ltk->bdaddr, &hcon->dst); |
| mgmt_new_ltk(hdev, smp->responder_ltk, persistent); |
| } |
| |
| if (smp->link_key) { |
| struct link_key *key; |
| u8 type; |
| |
| if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) |
| type = HCI_LK_DEBUG_COMBINATION; |
| else if (hcon->sec_level == BT_SECURITY_FIPS) |
| type = HCI_LK_AUTH_COMBINATION_P256; |
| else |
| type = HCI_LK_UNAUTH_COMBINATION_P256; |
| |
| key = hci_add_link_key(hdev, smp->conn->hcon, &hcon->dst, |
| smp->link_key, type, 0, &persistent); |
| if (key) { |
| mgmt_new_link_key(hdev, key, persistent); |
| |
| /* Don't keep debug keys around if the relevant |
| * flag is not set. |
| */ |
| if (!hci_dev_test_flag(hdev, HCI_KEEP_DEBUG_KEYS) && |
| key->type == HCI_LK_DEBUG_COMBINATION) { |
| list_del_rcu(&key->list); |
| kfree_rcu(key, rcu); |
| } |
| } |
| } |
| } |
| |
| static void sc_add_ltk(struct smp_chan *smp) |
| { |
| struct hci_conn *hcon = smp->conn->hcon; |
| u8 key_type, auth; |
| |
| if (test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags)) |
| key_type = SMP_LTK_P256_DEBUG; |
| else |
| key_type = SMP_LTK_P256; |
| |
| if (hcon->pending_sec_level == BT_SECURITY_FIPS) |
| auth = 1; |
| else |
| auth = 0; |
| |
| smp->ltk = hci_add_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, |
| key_type, auth, smp->tk, smp->enc_key_size, |
| 0, 0); |
| } |
| |
| static void sc_generate_link_key(struct smp_chan *smp) |
| { |
| /* From core spec. Spells out in ASCII as 'lebr'. */ |
| const u8 lebr[4] = { 0x72, 0x62, 0x65, 0x6c }; |
| |
| smp->link_key = kzalloc(16, GFP_KERNEL); |
| if (!smp->link_key) |
| return; |
| |
| if (test_bit(SMP_FLAG_CT2, &smp->flags)) { |
| /* SALT = 0x000000000000000000000000746D7031 */ |
| const u8 salt[16] = { 0x31, 0x70, 0x6d, 0x74 }; |
| |
| if (smp_h7(smp->tfm_cmac, smp->tk, salt, smp->link_key)) { |
| kfree_sensitive(smp->link_key); |
| smp->link_key = NULL; |
| return; |
| } |
| } else { |
| /* From core spec. Spells out in ASCII as 'tmp1'. */ |
| const u8 tmp1[4] = { 0x31, 0x70, 0x6d, 0x74 }; |
| |
| if (smp_h6(smp->tfm_cmac, smp->tk, tmp1, smp->link_key)) { |
| kfree_sensitive(smp->link_key); |
| smp->link_key = NULL; |
| return; |
| } |
| } |
| |
| if (smp_h6(smp->tfm_cmac, smp->link_key, lebr, smp->link_key)) { |
| kfree_sensitive(smp->link_key); |
| smp->link_key = NULL; |
| return; |
| } |
| } |
| |
| static void smp_allow_key_dist(struct smp_chan *smp) |
| { |
| /* Allow the first expected phase 3 PDU. The rest of the PDUs |
| * will be allowed in each PDU handler to ensure we receive |
| * them in the correct order. |
| */ |
| if (smp->remote_key_dist & SMP_DIST_ENC_KEY) |
| SMP_ALLOW_CMD(smp, SMP_CMD_ENCRYPT_INFO); |
| else if (smp->remote_key_dist & SMP_DIST_ID_KEY) |
| SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); |
| else if (smp->remote_key_dist & SMP_DIST_SIGN) |
| SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); |
| } |
| |
| static void sc_generate_ltk(struct smp_chan *smp) |
| { |
| /* From core spec. Spells out in ASCII as 'brle'. */ |
| const u8 brle[4] = { 0x65, 0x6c, 0x72, 0x62 }; |
| struct hci_conn *hcon = smp->conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| struct link_key *key; |
| |
| key = hci_find_link_key(hdev, &hcon->dst); |
| if (!key) { |
| bt_dev_err(hdev, "no Link Key found to generate LTK"); |
| return; |
| } |
| |
| if (key->type == HCI_LK_DEBUG_COMBINATION) |
| set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); |
| |
| if (test_bit(SMP_FLAG_CT2, &smp->flags)) { |
| /* SALT = 0x000000000000000000000000746D7032 */ |
| const u8 salt[16] = { 0x32, 0x70, 0x6d, 0x74 }; |
| |
| if (smp_h7(smp->tfm_cmac, key->val, salt, smp->tk)) |
| return; |
| } else { |
| /* From core spec. Spells out in ASCII as 'tmp2'. */ |
| const u8 tmp2[4] = { 0x32, 0x70, 0x6d, 0x74 }; |
| |
| if (smp_h6(smp->tfm_cmac, key->val, tmp2, smp->tk)) |
| return; |
| } |
| |
| if (smp_h6(smp->tfm_cmac, smp->tk, brle, smp->tk)) |
| return; |
| |
| sc_add_ltk(smp); |
| } |
| |
| static void smp_distribute_keys(struct smp_chan *smp) |
| { |
| struct smp_cmd_pairing *req, *rsp; |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| __u8 *keydist; |
| |
| bt_dev_dbg(hdev, "conn %p", conn); |
| |
| rsp = (void *) &smp->prsp[1]; |
| |
| /* The responder sends its keys first */ |
| if (hcon->out && (smp->remote_key_dist & KEY_DIST_MASK)) { |
| smp_allow_key_dist(smp); |
| return; |
| } |
| |
| req = (void *) &smp->preq[1]; |
| |
| if (hcon->out) { |
| keydist = &rsp->init_key_dist; |
| *keydist &= req->init_key_dist; |
| } else { |
| keydist = &rsp->resp_key_dist; |
| *keydist &= req->resp_key_dist; |
| } |
| |
| if (test_bit(SMP_FLAG_SC, &smp->flags)) { |
| if (hcon->type == LE_LINK && (*keydist & SMP_DIST_LINK_KEY)) |
| sc_generate_link_key(smp); |
| if (hcon->type == ACL_LINK && (*keydist & SMP_DIST_ENC_KEY)) |
| sc_generate_ltk(smp); |
| |
| /* Clear the keys which are generated but not distributed */ |
| *keydist &= ~SMP_SC_NO_DIST; |
| } |
| |
| bt_dev_dbg(hdev, "keydist 0x%x", *keydist); |
| |
| if (*keydist & SMP_DIST_ENC_KEY) { |
| struct smp_cmd_encrypt_info enc; |
| struct smp_cmd_initiator_ident ident; |
| struct smp_ltk *ltk; |
| u8 authenticated; |
| __le16 ediv; |
| __le64 rand; |
| |
| /* Make sure we generate only the significant amount of |
| * bytes based on the encryption key size, and set the rest |
| * of the value to zeroes. |
| */ |
| get_random_bytes(enc.ltk, smp->enc_key_size); |
| memset(enc.ltk + smp->enc_key_size, 0, |
| sizeof(enc.ltk) - smp->enc_key_size); |
| |
| get_random_bytes(&ediv, sizeof(ediv)); |
| get_random_bytes(&rand, sizeof(rand)); |
| |
| smp_send_cmd(conn, SMP_CMD_ENCRYPT_INFO, sizeof(enc), &enc); |
| |
| authenticated = hcon->sec_level == BT_SECURITY_HIGH; |
| ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, |
| SMP_LTK_RESPONDER, authenticated, enc.ltk, |
| smp->enc_key_size, ediv, rand); |
| smp->responder_ltk = ltk; |
| |
| ident.ediv = ediv; |
| ident.rand = rand; |
| |
| smp_send_cmd(conn, SMP_CMD_INITIATOR_IDENT, sizeof(ident), |
| &ident); |
| |
| *keydist &= ~SMP_DIST_ENC_KEY; |
| } |
| |
| if (*keydist & SMP_DIST_ID_KEY) { |
| struct smp_cmd_ident_addr_info addrinfo; |
| struct smp_cmd_ident_info idinfo; |
| |
| memcpy(idinfo.irk, hdev->irk, sizeof(idinfo.irk)); |
| |
| smp_send_cmd(conn, SMP_CMD_IDENT_INFO, sizeof(idinfo), &idinfo); |
| |
| /* The hci_conn contains the local identity address |
| * after the connection has been established. |
| * |
| * This is true even when the connection has been |
| * established using a resolvable random address. |
| */ |
| bacpy(&addrinfo.bdaddr, &hcon->src); |
| addrinfo.addr_type = hcon->src_type; |
| |
| smp_send_cmd(conn, SMP_CMD_IDENT_ADDR_INFO, sizeof(addrinfo), |
| &addrinfo); |
| |
| *keydist &= ~SMP_DIST_ID_KEY; |
| } |
| |
| if (*keydist & SMP_DIST_SIGN) { |
| struct smp_cmd_sign_info sign; |
| struct smp_csrk *csrk; |
| |
| /* Generate a new random key */ |
| get_random_bytes(sign.csrk, sizeof(sign.csrk)); |
| |
| csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); |
| if (csrk) { |
| if (hcon->sec_level > BT_SECURITY_MEDIUM) |
| csrk->type = MGMT_CSRK_LOCAL_AUTHENTICATED; |
| else |
| csrk->type = MGMT_CSRK_LOCAL_UNAUTHENTICATED; |
| memcpy(csrk->val, sign.csrk, sizeof(csrk->val)); |
| } |
| smp->responder_csrk = csrk; |
| |
| smp_send_cmd(conn, SMP_CMD_SIGN_INFO, sizeof(sign), &sign); |
| |
| *keydist &= ~SMP_DIST_SIGN; |
| } |
| |
| /* If there are still keys to be received wait for them */ |
| if (smp->remote_key_dist & KEY_DIST_MASK) { |
| smp_allow_key_dist(smp); |
| return; |
| } |
| |
| set_bit(SMP_FLAG_COMPLETE, &smp->flags); |
| smp_notify_keys(conn); |
| |
| smp_chan_destroy(conn); |
| } |
| |
| static void smp_timeout(struct work_struct *work) |
| { |
| struct smp_chan *smp = container_of(work, struct smp_chan, |
| security_timer.work); |
| struct l2cap_conn *conn = smp->conn; |
| |
| bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); |
| |
| hci_disconnect(conn->hcon, HCI_ERROR_REMOTE_USER_TERM); |
| } |
| |
| static struct smp_chan *smp_chan_create(struct l2cap_conn *conn) |
| { |
| struct hci_conn *hcon = conn->hcon; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp; |
| |
| smp = kzalloc(sizeof(*smp), GFP_ATOMIC); |
| if (!smp) |
| return NULL; |
| |
| smp->tfm_cmac = crypto_alloc_shash("cmac(aes)", 0, 0); |
| if (IS_ERR(smp->tfm_cmac)) { |
| bt_dev_err(hcon->hdev, "Unable to create CMAC crypto context"); |
| goto zfree_smp; |
| } |
| |
| smp->tfm_ecdh = crypto_alloc_kpp("ecdh-nist-p256", 0, 0); |
| if (IS_ERR(smp->tfm_ecdh)) { |
| bt_dev_err(hcon->hdev, "Unable to create ECDH crypto context"); |
| goto free_shash; |
| } |
| |
| smp->conn = conn; |
| chan->data = smp; |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_FAIL); |
| |
| INIT_DELAYED_WORK(&smp->security_timer, smp_timeout); |
| |
| hci_conn_hold(hcon); |
| |
| return smp; |
| |
| free_shash: |
| crypto_free_shash(smp->tfm_cmac); |
| zfree_smp: |
| kfree_sensitive(smp); |
| return NULL; |
| } |
| |
| 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 void sc_dhkey_check(struct smp_chan *smp) |
| { |
| 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]; |
| |
| 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); |
| } |
| |
| memset(r, 0, sizeof(r)); |
| |
| if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) |
| put_unaligned_le32(hcon->passkey_notify, r); |
| |
| if (smp->method == REQ_OOB) |
| memcpy(r, smp->rr, 16); |
| |
| 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); |
| } |
| |
| static u8 sc_passkey_send_confirm(struct smp_chan *smp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_cmd_pairing_confirm cfm; |
| u8 r; |
| |
| r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); |
| r |= 0x80; |
| |
| get_random_bytes(smp->prnd, sizeof(smp->prnd)); |
| |
| if (smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, r, |
| cfm.confirm_val)) |
| return SMP_UNSPECIFIED; |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); |
| |
| return 0; |
| } |
| |
| static u8 sc_passkey_round(struct smp_chan *smp, u8 smp_op) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| u8 cfm[16], r; |
| |
| /* Ignore the PDU if we've already done 20 rounds (0 - 19) */ |
| if (smp->passkey_round >= 20) |
| return 0; |
| |
| switch (smp_op) { |
| case SMP_CMD_PAIRING_RANDOM: |
| r = ((hcon->passkey_notify >> smp->passkey_round) & 0x01); |
| r |= 0x80; |
| |
| if (smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, |
| smp->rrnd, r, cfm)) |
| return SMP_UNSPECIFIED; |
| |
| if (crypto_memneq(smp->pcnf, cfm, 16)) |
| return SMP_CONFIRM_FAILED; |
| |
| smp->passkey_round++; |
| |
| if (smp->passkey_round == 20) { |
| /* Generate MacKey and LTK */ |
| if (sc_mackey_and_ltk(smp, smp->mackey, smp->tk)) |
| return SMP_UNSPECIFIED; |
| } |
| |
| /* The round is only complete when the initiator |
| * receives pairing random. |
| */ |
| if (!hcon->out) { |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, |
| sizeof(smp->prnd), smp->prnd); |
| if (smp->passkey_round == 20) |
| SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); |
| else |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| return 0; |
| } |
| |
| /* Start the next round */ |
| if (smp->passkey_round != 20) |
| return sc_passkey_round(smp, 0); |
| |
| /* Passkey rounds are complete - start DHKey Check */ |
| sc_dhkey_check(smp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); |
| |
| break; |
| |
| case SMP_CMD_PAIRING_CONFIRM: |
| if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { |
| set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); |
| return 0; |
| } |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| |
| if (hcon->out) { |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, |
| sizeof(smp->prnd), smp->prnd); |
| return 0; |
| } |
| |
| return sc_passkey_send_confirm(smp); |
| |
| case SMP_CMD_PUBLIC_KEY: |
| default: |
| /* Initiating device starts the round */ |
| if (!hcon->out) |
| return 0; |
| |
| bt_dev_dbg(hdev, "Starting passkey round %u", |
| smp->passkey_round + 1); |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| |
| return sc_passkey_send_confirm(smp); |
| } |
| |
| return 0; |
| } |
| |
| static int sc_user_reply(struct smp_chan *smp, u16 mgmt_op, __le32 passkey) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| u8 smp_op; |
| |
| clear_bit(SMP_FLAG_WAIT_USER, &smp->flags); |
| |
| 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; |
| case MGMT_OP_USER_PASSKEY_REPLY: |
| hcon->passkey_notify = le32_to_cpu(passkey); |
| smp->passkey_round = 0; |
| |
| if (test_and_clear_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) |
| smp_op = SMP_CMD_PAIRING_CONFIRM; |
| else |
| smp_op = 0; |
| |
| if (sc_passkey_round(smp, smp_op)) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| /* Initiator sends DHKey check first */ |
| if (hcon->out) { |
| sc_dhkey_check(smp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); |
| } else if (test_and_clear_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags)) { |
| sc_dhkey_check(smp); |
| sc_add_ltk(smp); |
| } |
| |
| return 0; |
| } |
| |
| int smp_user_confirm_reply(struct hci_conn *hcon, u16 mgmt_op, __le32 passkey) |
| { |
| struct l2cap_conn *conn = hcon->l2cap_data; |
| struct l2cap_chan *chan; |
| struct smp_chan *smp; |
| u32 value; |
| int err; |
| |
| if (!conn) |
| return -ENOTCONN; |
| |
| bt_dev_dbg(conn->hcon->hdev, ""); |
| |
| chan = conn->smp; |
| if (!chan) |
| return -ENOTCONN; |
| |
| l2cap_chan_lock(chan); |
| if (!chan->data) { |
| err = -ENOTCONN; |
| goto unlock; |
| } |
| |
| 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); |
| memset(smp->tk, 0, sizeof(smp->tk)); |
| bt_dev_dbg(conn->hcon->hdev, "PassKey: %u", value); |
| put_unaligned_le32(value, smp->tk); |
| fallthrough; |
| case MGMT_OP_USER_CONFIRM_REPLY: |
| set_bit(SMP_FLAG_TK_VALID, &smp->flags); |
| break; |
| case MGMT_OP_USER_PASSKEY_NEG_REPLY: |
| case MGMT_OP_USER_CONFIRM_NEG_REPLY: |
| smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); |
| err = 0; |
| goto unlock; |
| default: |
| smp_failure(conn, SMP_PASSKEY_ENTRY_FAILED); |
| err = -EOPNOTSUPP; |
| goto unlock; |
| } |
| |
| err = 0; |
| |
| /* If it is our turn to send Pairing Confirm, do so now */ |
| if (test_bit(SMP_FLAG_CFM_PENDING, &smp->flags)) { |
| u8 rsp = smp_confirm(smp); |
| if (rsp) |
| smp_failure(conn, rsp); |
| } |
| |
| unlock: |
| l2cap_chan_unlock(chan); |
| return err; |
| } |
| |
| static void build_bredr_pairing_cmd(struct smp_chan *smp, |
| struct smp_cmd_pairing *req, |
| struct smp_cmd_pairing *rsp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_dev *hdev = conn->hcon->hdev; |
| u8 local_dist = 0, remote_dist = 0; |
| |
| if (hci_dev_test_flag(hdev, HCI_BONDABLE)) { |
| local_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; |
| remote_dist = SMP_DIST_ENC_KEY | SMP_DIST_SIGN; |
| } |
| |
| if (hci_dev_test_flag(hdev, HCI_RPA_RESOLVING)) |
| remote_dist |= SMP_DIST_ID_KEY; |
| |
| if (hci_dev_test_flag(hdev, HCI_PRIVACY)) |
| local_dist |= SMP_DIST_ID_KEY; |
| |
| if (!rsp) { |
| memset(req, 0, sizeof(*req)); |
| |
| req->auth_req = SMP_AUTH_CT2; |
| req->init_key_dist = local_dist; |
| req->resp_key_dist = remote_dist; |
| req->max_key_size = conn->hcon->enc_key_size; |
| |
| smp->remote_key_dist = remote_dist; |
| |
| return; |
| } |
| |
| memset(rsp, 0, sizeof(*rsp)); |
| |
| rsp->auth_req = SMP_AUTH_CT2; |
| rsp->max_key_size = conn->hcon->enc_key_size; |
| rsp->init_key_dist = req->init_key_dist & remote_dist; |
| rsp->resp_key_dist = req->resp_key_dist & local_dist; |
| |
| smp->remote_key_dist = rsp->init_key_dist; |
| } |
| |
| static u8 smp_cmd_pairing_req(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_pairing rsp, *req = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct hci_dev *hdev = conn->hcon->hdev; |
| struct smp_chan *smp; |
| u8 key_size, auth, sec_level; |
| int ret; |
| |
| bt_dev_dbg(hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*req)) |
| return SMP_INVALID_PARAMS; |
| |
| if (conn->hcon->role != HCI_ROLE_SLAVE) |
| return SMP_CMD_NOTSUPP; |
| |
| if (!chan->data) |
| smp = smp_chan_create(conn); |
| else |
| smp = chan->data; |
| |
| if (!smp) |
| return SMP_UNSPECIFIED; |
| |
| /* We didn't start the pairing, so match remote */ |
| auth = req->auth_req & AUTH_REQ_MASK(hdev); |
| |
| if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && |
| (auth & SMP_AUTH_BONDING)) |
| return SMP_PAIRING_NOTSUPP; |
| |
| if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) |
| return SMP_AUTH_REQUIREMENTS; |
| |
| smp->preq[0] = SMP_CMD_PAIRING_REQ; |
| 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 && SMP_DEV(hdev)->local_oob) |
| 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 */ |
| if (!test_bit(HCI_CONN_AES_CCM, &conn->hcon->flags) && |
| !hci_dev_test_flag(hdev, HCI_FORCE_BREDR_SMP)) |
| return SMP_CROSS_TRANSP_NOT_ALLOWED; |
| |
| set_bit(SMP_FLAG_SC, &smp->flags); |
| |
| build_bredr_pairing_cmd(smp, req, &rsp); |
| |
| if (req->auth_req & SMP_AUTH_CT2) |
| set_bit(SMP_FLAG_CT2, &smp->flags); |
| |
| key_size = min(req->max_key_size, rsp.max_key_size); |
| if (check_enc_key_size(conn, key_size)) |
| return SMP_ENC_KEY_SIZE; |
| |
| /* Clear bits which are generated but not distributed */ |
| smp->remote_key_dist &= ~SMP_SC_NO_DIST; |
| |
| smp->prsp[0] = SMP_CMD_PAIRING_RSP; |
| memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); |
| |
| smp_distribute_keys(smp); |
| return 0; |
| } |
| |
| build_pairing_cmd(conn, req, &rsp, auth); |
| |
| if (rsp.auth_req & SMP_AUTH_SC) { |
| set_bit(SMP_FLAG_SC, &smp->flags); |
| |
| if (rsp.auth_req & SMP_AUTH_CT2) |
| set_bit(SMP_FLAG_CT2, &smp->flags); |
| } |
| |
| if (conn->hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) |
| sec_level = BT_SECURITY_MEDIUM; |
| else |
| sec_level = authreq_to_seclevel(auth); |
| |
| if (sec_level > conn->hcon->pending_sec_level) |
| conn->hcon->pending_sec_level = sec_level; |
| |
| /* If we need MITM check that it can be achieved */ |
| if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { |
| u8 method; |
| |
| method = get_auth_method(smp, conn->hcon->io_capability, |
| req->io_capability); |
| if (method == JUST_WORKS || method == JUST_CFM) |
| return SMP_AUTH_REQUIREMENTS; |
| } |
| |
| key_size = min(req->max_key_size, rsp.max_key_size); |
| if (check_enc_key_size(conn, key_size)) |
| return SMP_ENC_KEY_SIZE; |
| |
| get_random_bytes(smp->prnd, sizeof(smp->prnd)); |
| |
| smp->prsp[0] = SMP_CMD_PAIRING_RSP; |
| memcpy(&smp->prsp[1], &rsp, sizeof(rsp)); |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RSP, sizeof(rsp), &rsp); |
| |
| 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 */ |
| smp->remote_key_dist &= ~SMP_SC_NO_DIST; |
| /* Wait for Public Key from Initiating Device */ |
| return 0; |
| } |
| |
| /* Request setup of TK */ |
| ret = tk_request(conn, 0, auth, rsp.io_capability, req->io_capability); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| return 0; |
| } |
| |
| static u8 sc_send_public_key(struct smp_chan *smp) |
| { |
| struct hci_dev *hdev = smp->conn->hcon->hdev; |
| |
| bt_dev_dbg(hdev, ""); |
| |
| if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { |
| struct l2cap_chan *chan = hdev->smp_data; |
| struct smp_dev *smp_dev; |
| |
| if (!chan || !chan->data) |
| return SMP_UNSPECIFIED; |
| |
| smp_dev = chan->data; |
| |
| memcpy(smp->local_pk, smp_dev->local_pk, 64); |
| memcpy(smp->lr, smp_dev->local_rand, 16); |
| |
| if (smp_dev->debug_key) |
| set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); |
| |
| goto done; |
| } |
| |
| if (hci_dev_test_flag(hdev, HCI_USE_DEBUG_KEYS)) { |
| bt_dev_dbg(hdev, "Using debug keys"); |
| if (set_ecdh_privkey(smp->tfm_ecdh, debug_sk)) |
| return SMP_UNSPECIFIED; |
| memcpy(smp->local_pk, debug_pk, 64); |
| set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); |
| } else { |
| while (true) { |
| /* Generate key pair for Secure Connections */ |
| if (generate_ecdh_keys(smp->tfm_ecdh, smp->local_pk)) |
| return SMP_UNSPECIFIED; |
| |
| /* This is unlikely, but we need to check that |
| * we didn't accidentally generate a debug key. |
| */ |
| if (crypto_memneq(smp->local_pk, debug_pk, 64)) |
| break; |
| } |
| } |
| |
| done: |
| SMP_DBG("Local Public Key X: %32phN", smp->local_pk); |
| SMP_DBG("Local Public Key Y: %32phN", smp->local_pk + 32); |
| |
| smp_send_cmd(smp->conn, SMP_CMD_PUBLIC_KEY, 64, smp->local_pk); |
| |
| 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 l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_dev *hdev = conn->hcon->hdev; |
| u8 key_size, auth; |
| int ret; |
| |
| bt_dev_dbg(hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*rsp)) |
| return SMP_INVALID_PARAMS; |
| |
| if (conn->hcon->role != HCI_ROLE_MASTER) |
| return SMP_CMD_NOTSUPP; |
| |
| skb_pull(skb, sizeof(*rsp)); |
| |
| req = (void *) &smp->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; |
| |
| auth = rsp->auth_req & AUTH_REQ_MASK(hdev); |
| |
| 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 && SMP_DEV(hdev)->local_oob) |
| set_bit(SMP_FLAG_LOCAL_OOB, &smp->flags); |
| |
| smp->prsp[0] = SMP_CMD_PAIRING_RSP; |
| memcpy(&smp->prsp[1], rsp, sizeof(*rsp)); |
| |
| /* Update remote key distribution in case the remote cleared |
| * some bits that we had enabled in our request. |
| */ |
| smp->remote_key_dist &= rsp->resp_key_dist; |
| |
| if ((req->auth_req & SMP_AUTH_CT2) && (auth & SMP_AUTH_CT2)) |
| set_bit(SMP_FLAG_CT2, &smp->flags); |
| |
| /* For BR/EDR this means we're done and can start phase 3 */ |
| if (conn->hcon->type == ACL_LINK) { |
| /* Clear bits which are generated but not distributed */ |
| smp->remote_key_dist &= ~SMP_SC_NO_DIST; |
| smp_distribute_keys(smp); |
| return 0; |
| } |
| |
| if ((req->auth_req & SMP_AUTH_SC) && (auth & SMP_AUTH_SC)) |
| set_bit(SMP_FLAG_SC, &smp->flags); |
| else if (conn->hcon->pending_sec_level > BT_SECURITY_HIGH) |
| conn->hcon->pending_sec_level = BT_SECURITY_HIGH; |
| |
| /* If we need MITM check that it can be achieved */ |
| if (conn->hcon->pending_sec_level >= BT_SECURITY_HIGH) { |
| u8 method; |
| |
| method = get_auth_method(smp, req->io_capability, |
| rsp->io_capability); |
| if (method == JUST_WORKS || method == JUST_CFM) |
| return SMP_AUTH_REQUIREMENTS; |
| } |
| |
| get_random_bytes(smp->prnd, sizeof(smp->prnd)); |
| |
| /* Update remote key distribution in case the remote cleared |
| * some bits that we had enabled in our request. |
| */ |
| smp->remote_key_dist &= rsp->resp_key_dist; |
| |
| if (test_bit(SMP_FLAG_SC, &smp->flags)) { |
| /* Clear bits which are generated but not distributed */ |
| smp->remote_key_dist &= ~SMP_SC_NO_DIST; |
| SMP_ALLOW_CMD(smp, SMP_CMD_PUBLIC_KEY); |
| return sc_send_public_key(smp); |
| } |
| |
| auth |= req->auth_req; |
| |
| ret = tk_request(conn, 0, auth, req->io_capability, rsp->io_capability); |
| if (ret) |
| return SMP_UNSPECIFIED; |
| |
| set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); |
| |
| /* Can't compose response until we have been confirmed */ |
| if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) |
| return smp_confirm(smp); |
| |
| return 0; |
| } |
| |
| static u8 sc_check_confirm(struct smp_chan *smp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| |
| bt_dev_dbg(conn->hcon->hdev, ""); |
| |
| if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) |
| return sc_passkey_round(smp, SMP_CMD_PAIRING_CONFIRM); |
| |
| if (conn->hcon->out) { |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), |
| smp->prnd); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| } |
| |
| 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 responder role */ |
| if (hcon->out) |
| return SMP_UNSPECIFIED; |
| |
| if (hci_dev_test_flag(hdev, HCI_SC_ONLY)) { |
| bt_dev_err(hdev, "refusing legacy fallback in SC-only mode"); |
| return SMP_UNSPECIFIED; |
| } |
| |
| bt_dev_err(hdev, "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_dev_err(hdev, "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; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| struct hci_dev *hdev = hcon->hdev; |
| |
| bt_dev_dbg(hdev, "conn %p %s", conn, |
| hcon->out ? "initiator" : "responder"); |
| |
| if (skb->len < sizeof(smp->pcnf)) |
| return SMP_INVALID_PARAMS; |
| |
| memcpy(smp->pcnf, skb->data, sizeof(smp->pcnf)); |
| skb_pull(skb, sizeof(smp->pcnf)); |
| |
| 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_dev_err(hdev, "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), |
| smp->prnd); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| return 0; |
| } |
| |
| if (test_bit(SMP_FLAG_TK_VALID, &smp->flags)) |
| return smp_confirm(smp); |
| |
| set_bit(SMP_FLAG_CFM_PENDING, &smp->flags); |
| |
| return 0; |
| } |
| |
| static u8 smp_cmd_pairing_random(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| u8 *pkax, *pkbx, *na, *nb, confirm_hint; |
| u32 passkey; |
| int err; |
| |
| bt_dev_dbg(hcon->hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(smp->rrnd)) |
| return SMP_INVALID_PARAMS; |
| |
| memcpy(smp->rrnd, skb->data, sizeof(smp->rrnd)); |
| skb_pull(skb, sizeof(smp->rrnd)); |
| |
| if (!test_bit(SMP_FLAG_SC, &smp->flags)) |
| return smp_random(smp); |
| |
| if (hcon->out) { |
| pkax = smp->local_pk; |
| pkbx = smp->remote_pk; |
| na = smp->prnd; |
| nb = smp->rrnd; |
| } else { |
| pkax = smp->remote_pk; |
| pkbx = smp->local_pk; |
| na = smp->rrnd; |
| nb = smp->prnd; |
| } |
| |
| if (smp->method == REQ_OOB) { |
| if (!hcon->out) |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, |
| sizeof(smp->prnd), smp->prnd); |
| SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); |
| goto mackey_and_ltk; |
| } |
| |
| /* Passkey entry has special treatment */ |
| if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) |
| return sc_passkey_round(smp, SMP_CMD_PAIRING_RANDOM); |
| |
| if (hcon->out) { |
| u8 cfm[16]; |
| |
| err = smp_f4(smp->tfm_cmac, smp->remote_pk, smp->local_pk, |
| smp->rrnd, 0, cfm); |
| if (err) |
| return SMP_UNSPECIFIED; |
| |
| if (crypto_memneq(smp->pcnf, cfm, 16)) |
| return SMP_CONFIRM_FAILED; |
| } else { |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, sizeof(smp->prnd), |
| smp->prnd); |
| SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); |
| |
| /* Only Just-Works pairing requires extra checks */ |
| if (smp->method != JUST_WORKS) |
| goto mackey_and_ltk; |
| |
| /* If there already exists long term key in local host, leave |
| * the decision to user space since the remote device could |
| * be legitimate or malicious. |
| */ |
| if (hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, |
| hcon->role)) { |
| /* Set passkey to 0. The value can be any number since |
| * it'll be ignored anyway. |
| */ |
| passkey = 0; |
| confirm_hint = 1; |
| goto confirm; |
| } |
| } |
| |
| mackey_and_ltk: |
| /* Generate MacKey and LTK */ |
| err = sc_mackey_and_ltk(smp, smp->mackey, smp->tk); |
| if (err) |
| return SMP_UNSPECIFIED; |
| |
| if (smp->method == REQ_OOB) { |
| if (hcon->out) { |
| sc_dhkey_check(smp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_DHKEY_CHECK); |
| } |
| return 0; |
| } |
| |
| err = smp_g2(smp->tfm_cmac, pkax, pkbx, na, nb, &passkey); |
| if (err) |
| return SMP_UNSPECIFIED; |
| |
| confirm_hint = 0; |
| |
| confirm: |
| if (smp->method == JUST_WORKS) |
| confirm_hint = 1; |
| |
| err = mgmt_user_confirm_request(hcon->hdev, &hcon->dst, hcon->type, |
| hcon->dst_type, passkey, confirm_hint); |
| if (err) |
| return SMP_UNSPECIFIED; |
| |
| set_bit(SMP_FLAG_WAIT_USER, &smp->flags); |
| |
| return 0; |
| } |
| |
| static bool smp_ltk_encrypt(struct l2cap_conn *conn, u8 sec_level) |
| { |
| struct smp_ltk *key; |
| struct hci_conn *hcon = conn->hcon; |
| |
| key = hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role); |
| if (!key) |
| return false; |
| |
| if (smp_ltk_sec_level(key) < sec_level) |
| return false; |
| |
| if (test_and_set_bit(HCI_CONN_ENCRYPT_PEND, &hcon->flags)) |
| return true; |
| |
| hci_le_start_enc(hcon, key->ediv, key->rand, key->val, key->enc_size); |
| hcon->enc_key_size = key->enc_size; |
| |
| /* We never store STKs for initiator role, so clear this flag */ |
| clear_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags); |
| |
| return true; |
| } |
| |
| bool smp_sufficient_security(struct hci_conn *hcon, u8 sec_level, |
| enum smp_key_pref key_pref) |
| { |
| if (sec_level == BT_SECURITY_LOW) |
| return true; |
| |
| /* If we're encrypted with an STK but the caller prefers using |
| * LTK claim insufficient security. This way we allow the |
| * connection to be re-encrypted with an LTK, even if the LTK |
| * provides the same level of security. Only exception is if we |
| * don't have an LTK (e.g. because of key distribution bits). |
| */ |
| if (key_pref == SMP_USE_LTK && |
| test_bit(HCI_CONN_STK_ENCRYPT, &hcon->flags) && |
| hci_find_ltk(hcon->hdev, &hcon->dst, hcon->dst_type, hcon->role)) |
| return false; |
| |
| if (hcon->sec_level >= sec_level) |
| return true; |
| |
| return false; |
| } |
| |
| 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; |
| struct hci_dev *hdev = hcon->hdev; |
| struct smp_chan *smp; |
| u8 sec_level, auth; |
| |
| bt_dev_dbg(hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| if (hcon->role != HCI_ROLE_MASTER) |
| return SMP_CMD_NOTSUPP; |
| |
| auth = rp->auth_req & AUTH_REQ_MASK(hdev); |
| |
| if (hci_dev_test_flag(hdev, HCI_SC_ONLY) && !(auth & SMP_AUTH_SC)) |
| return SMP_AUTH_REQUIREMENTS; |
| |
| if (hcon->io_capability == HCI_IO_NO_INPUT_OUTPUT) |
| sec_level = BT_SECURITY_MEDIUM; |
| else |
| sec_level = authreq_to_seclevel(auth); |
| |
| if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) { |
| /* If link is already encrypted with sufficient security we |
| * still need refresh encryption as per Core Spec 5.0 Vol 3, |
| * Part H 2.4.6 |
| */ |
| smp_ltk_encrypt(conn, hcon->sec_level); |
| return 0; |
| } |
| |
| if (sec_level > hcon->pending_sec_level) |
| hcon->pending_sec_level = sec_level; |
| |
| if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) |
| return 0; |
| |
| smp = smp_chan_create(conn); |
| if (!smp) |
| return SMP_UNSPECIFIED; |
| |
| if (!hci_dev_test_flag(hdev, HCI_BONDABLE) && |
| (auth & SMP_AUTH_BONDING)) |
| return SMP_PAIRING_NOTSUPP; |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| memset(&cp, 0, sizeof(cp)); |
| build_pairing_cmd(conn, &cp, NULL, auth); |
| |
| smp->preq[0] = SMP_CMD_PAIRING_REQ; |
| memcpy(&smp->preq[1], &cp, sizeof(cp)); |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); |
| |
| return 0; |
| } |
| |
| int smp_conn_security(struct hci_conn *hcon, __u8 sec_level) |
| { |
| struct l2cap_conn *conn = hcon->l2cap_data; |
| struct l2cap_chan *chan; |
| struct smp_chan *smp; |
| __u8 authreq; |
| int ret; |
| |
| bt_dev_dbg(hcon->hdev, "conn %p hcon %p level 0x%2.2x", conn, hcon, |
| sec_level); |
| |
| /* This may be NULL if there's an unexpected disconnection */ |
| if (!conn) |
| return 1; |
| |
| if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) |
| return 1; |
| |
| if (smp_sufficient_security(hcon, sec_level, SMP_USE_LTK)) |
| return 1; |
| |
| if (sec_level > hcon->pending_sec_level) |
| hcon->pending_sec_level = sec_level; |
| |
| if (hcon->role == HCI_ROLE_MASTER) |
| if (smp_ltk_encrypt(conn, hcon->pending_sec_level)) |
| return 0; |
| |
| chan = conn->smp; |
| if (!chan) { |
| bt_dev_err(hcon->hdev, "security requested but not available"); |
| return 1; |
| } |
| |
| l2cap_chan_lock(chan); |
| |
| /* If SMP is already in progress ignore this request */ |
| if (chan->data) { |
| ret = 0; |
| goto unlock; |
| } |
| |
| smp = smp_chan_create(conn); |
| if (!smp) { |
| ret = 1; |
| goto unlock; |
| } |
| |
| authreq = seclevel_to_authreq(sec_level); |
| |
| if (hci_dev_test_flag(hcon->hdev, HCI_SC_ENABLED)) { |
| authreq |= SMP_AUTH_SC; |
| if (hci_dev_test_flag(hcon->hdev, HCI_SSP_ENABLED)) |
| authreq |= SMP_AUTH_CT2; |
| } |
| |
| /* Don't attempt to set MITM if setting is overridden by debugfs |
| * Needed to pass certification test SM/MAS/PKE/BV-01-C |
| */ |
| if (!hci_dev_test_flag(hcon->hdev, HCI_FORCE_NO_MITM)) { |
| /* Require MITM if IO Capability allows or the security level |
| * requires it. |
| */ |
| if (hcon->io_capability != HCI_IO_NO_INPUT_OUTPUT || |
| hcon->pending_sec_level > BT_SECURITY_MEDIUM) |
| authreq |= SMP_AUTH_MITM; |
| } |
| |
| if (hcon->role == HCI_ROLE_MASTER) { |
| struct smp_cmd_pairing cp; |
| |
| build_pairing_cmd(conn, &cp, NULL, authreq); |
| smp->preq[0] = SMP_CMD_PAIRING_REQ; |
| memcpy(&smp->preq[1], &cp, sizeof(cp)); |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_REQ, sizeof(cp), &cp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RSP); |
| } else { |
| struct smp_cmd_security_req cp; |
| cp.auth_req = authreq; |
| smp_send_cmd(conn, SMP_CMD_SECURITY_REQ, sizeof(cp), &cp); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_REQ); |
| } |
| |
| set_bit(SMP_FLAG_INITIATOR, &smp->flags); |
| ret = 0; |
| |
| unlock: |
| l2cap_chan_unlock(chan); |
| return ret; |
| } |
| |
| int smp_cancel_and_remove_pairing(struct hci_dev *hdev, bdaddr_t *bdaddr, |
| u8 addr_type) |
| { |
| struct hci_conn *hcon; |
| struct l2cap_conn *conn; |
| struct l2cap_chan *chan; |
| struct smp_chan *smp; |
| int err; |
| |
| err = hci_remove_ltk(hdev, bdaddr, addr_type); |
| hci_remove_irk(hdev, bdaddr, addr_type); |
| |
| hcon = hci_conn_hash_lookup_le(hdev, bdaddr, addr_type); |
| if (!hcon) |
| goto done; |
| |
| conn = hcon->l2cap_data; |
| if (!conn) |
| goto done; |
| |
| chan = conn->smp; |
| if (!chan) |
| goto done; |
| |
| l2cap_chan_lock(chan); |
| |
| smp = chan->data; |
| if (smp) { |
| /* Set keys to NULL to make sure smp_failure() does not try to |
| * remove and free already invalidated rcu list entries. */ |
| smp->ltk = NULL; |
| smp->responder_ltk = NULL; |
| smp->remote_irk = NULL; |
| |
| if (test_bit(SMP_FLAG_COMPLETE, &smp->flags)) |
| smp_failure(conn, 0); |
| else |
| smp_failure(conn, SMP_UNSPECIFIED); |
| err = 0; |
| } |
| |
| l2cap_chan_unlock(chan); |
| |
| done: |
| return err; |
| } |
| |
| static int smp_cmd_encrypt_info(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_encrypt_info *rp = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| |
| bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Pairing is aborted if any blocked keys are distributed */ |
| if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_LTK, |
| rp->ltk)) { |
| bt_dev_warn_ratelimited(conn->hcon->hdev, |
| "LTK blocked for %pMR", |
| &conn->hcon->dst); |
| return SMP_INVALID_PARAMS; |
| } |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_INITIATOR_IDENT); |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| memcpy(smp->tk, rp->ltk, sizeof(smp->tk)); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_initiator_ident(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_initiator_ident *rp = (void *)skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_dev *hdev = conn->hcon->hdev; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_ltk *ltk; |
| u8 authenticated; |
| |
| bt_dev_dbg(hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Mark the information as received */ |
| smp->remote_key_dist &= ~SMP_DIST_ENC_KEY; |
| |
| if (smp->remote_key_dist & SMP_DIST_ID_KEY) |
| SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_INFO); |
| else if (smp->remote_key_dist & SMP_DIST_SIGN) |
| SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| authenticated = (hcon->sec_level == BT_SECURITY_HIGH); |
| ltk = hci_add_ltk(hdev, &hcon->dst, hcon->dst_type, SMP_LTK, |
| authenticated, smp->tk, smp->enc_key_size, |
| rp->ediv, rp->rand); |
| smp->ltk = ltk; |
| if (!(smp->remote_key_dist & KEY_DIST_MASK)) |
| smp_distribute_keys(smp); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_ident_info(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_ident_info *info = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| |
| bt_dev_dbg(conn->hcon->hdev, ""); |
| |
| if (skb->len < sizeof(*info)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Pairing is aborted if any blocked keys are distributed */ |
| if (hci_is_blocked_key(conn->hcon->hdev, HCI_BLOCKED_KEY_TYPE_IRK, |
| info->irk)) { |
| bt_dev_warn_ratelimited(conn->hcon->hdev, |
| "Identity key blocked for %pMR", |
| &conn->hcon->dst); |
| return SMP_INVALID_PARAMS; |
| } |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_IDENT_ADDR_INFO); |
| |
| skb_pull(skb, sizeof(*info)); |
| |
| memcpy(smp->irk, info->irk, 16); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_ident_addr_info(struct l2cap_conn *conn, |
| struct sk_buff *skb) |
| { |
| struct smp_cmd_ident_addr_info *info = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_conn *hcon = conn->hcon; |
| bdaddr_t rpa; |
| |
| bt_dev_dbg(hcon->hdev, ""); |
| |
| if (skb->len < sizeof(*info)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Mark the information as received */ |
| smp->remote_key_dist &= ~SMP_DIST_ID_KEY; |
| |
| if (smp->remote_key_dist & SMP_DIST_SIGN) |
| SMP_ALLOW_CMD(smp, SMP_CMD_SIGN_INFO); |
| |
| skb_pull(skb, sizeof(*info)); |
| |
| /* Strictly speaking the Core Specification (4.1) allows sending |
| * an empty address which would force us to rely on just the IRK |
| * as "identity information". However, since such |
| * implementations are not known of and in order to not over |
| * complicate our implementation, simply pretend that we never |
| * received an IRK for such a device. |
| * |
| * The Identity Address must also be a Static Random or Public |
| * Address, which hci_is_identity_address() checks for. |
| */ |
| if (!bacmp(&info->bdaddr, BDADDR_ANY) || |
| !hci_is_identity_address(&info->bdaddr, info->addr_type)) { |
| bt_dev_err(hcon->hdev, "ignoring IRK with no identity address"); |
| goto distribute; |
| } |
| |
| /* Drop IRK if peer is using identity address during pairing but is |
| * providing different address as identity information. |
| * |
| * Microsoft Surface Precision Mouse is known to have this bug. |
| */ |
| if (hci_is_identity_address(&hcon->dst, hcon->dst_type) && |
| (bacmp(&info->bdaddr, &hcon->dst) || |
| info->addr_type != hcon->dst_type)) { |
| bt_dev_err(hcon->hdev, |
| "ignoring IRK with invalid identity address"); |
| goto distribute; |
| } |
| |
| bacpy(&smp->id_addr, &info->bdaddr); |
| smp->id_addr_type = info->addr_type; |
| |
| if (hci_bdaddr_is_rpa(&hcon->dst, hcon->dst_type)) |
| bacpy(&rpa, &hcon->dst); |
| else |
| bacpy(&rpa, BDADDR_ANY); |
| |
| smp->remote_irk = hci_add_irk(conn->hcon->hdev, &smp->id_addr, |
| smp->id_addr_type, smp->irk, &rpa); |
| |
| distribute: |
| if (!(smp->remote_key_dist & KEY_DIST_MASK)) |
| smp_distribute_keys(smp); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_sign_info(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_sign_info *rp = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct smp_csrk *csrk; |
| |
| bt_dev_dbg(conn->hcon->hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*rp)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Mark the information as received */ |
| smp->remote_key_dist &= ~SMP_DIST_SIGN; |
| |
| skb_pull(skb, sizeof(*rp)); |
| |
| csrk = kzalloc(sizeof(*csrk), GFP_KERNEL); |
| if (csrk) { |
| if (conn->hcon->sec_level > BT_SECURITY_MEDIUM) |
| csrk->type = MGMT_CSRK_REMOTE_AUTHENTICATED; |
| else |
| csrk->type = MGMT_CSRK_REMOTE_UNAUTHENTICATED; |
| memcpy(csrk->val, rp->csrk, sizeof(csrk->val)); |
| } |
| smp->csrk = csrk; |
| smp_distribute_keys(smp); |
| |
| return 0; |
| } |
| |
| static u8 sc_select_method(struct smp_chan *smp) |
| { |
| struct l2cap_conn *conn = smp->conn; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_cmd_pairing *local, *remote; |
| u8 local_mitm, remote_mitm, local_io, remote_io, method; |
| |
| if (test_bit(SMP_FLAG_REMOTE_OOB, &smp->flags) || |
| test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) |
| return REQ_OOB; |
| |
| /* The preq/prsp contain the raw Pairing Request/Response PDUs |
| * which are needed as inputs to some crypto functions. To get |
| * the "struct smp_cmd_pairing" from them we need to skip the |
| * first byte which contains the opcode. |
| */ |
| if (hcon->out) { |
| local = (void *) &smp->preq[1]; |
| remote = (void *) &smp->prsp[1]; |
| } else { |
| local = (void *) &smp->prsp[1]; |
| remote = (void *) &smp->preq[1]; |
| } |
| |
| local_io = local->io_capability; |
| remote_io = remote->io_capability; |
| |
| local_mitm = (local->auth_req & SMP_AUTH_MITM); |
| remote_mitm = (remote->auth_req & SMP_AUTH_MITM); |
| |
| /* If either side wants MITM, look up the method from the table, |
| * otherwise use JUST WORKS. |
| */ |
| if (local_mitm || remote_mitm) |
| method = get_auth_method(smp, local_io, remote_io); |
| else |
| method = JUST_WORKS; |
| |
| /* Don't confirm locally initiated pairing attempts */ |
| if (method == JUST_CFM && test_bit(SMP_FLAG_INITIATOR, &smp->flags)) |
| method = JUST_WORKS; |
| |
| return method; |
| } |
| |
| static int smp_cmd_public_key(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_public_key *key = (void *) skb->data; |
| struct hci_conn *hcon = conn->hcon; |
| struct l2cap_chan *chan = conn->smp; |
| struct smp_chan *smp = chan->data; |
| struct hci_dev *hdev = hcon->hdev; |
| struct crypto_kpp *tfm_ecdh; |
| struct smp_cmd_pairing_confirm cfm; |
| int err; |
| |
| bt_dev_dbg(hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*key)) |
| return SMP_INVALID_PARAMS; |
| |
| /* Check if remote and local public keys are the same and debug key is |
| * not in use. |
| */ |
| if (!test_bit(SMP_FLAG_DEBUG_KEY, &smp->flags) && |
| !crypto_memneq(key, smp->local_pk, 64)) { |
| bt_dev_err(hdev, "Remote and local public keys are identical"); |
| return SMP_UNSPECIFIED; |
| } |
| |
| 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 (crypto_memneq(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. |
| */ |
| if (!hcon->out) { |
| err = sc_send_public_key(smp); |
| if (err) |
| return err; |
| } |
| |
| SMP_DBG("Remote Public Key X: %32phN", smp->remote_pk); |
| SMP_DBG("Remote Public Key Y: %32phN", smp->remote_pk + 32); |
| |
| /* Compute the shared secret on the same crypto tfm on which the private |
| * key was set/generated. |
| */ |
| if (test_bit(SMP_FLAG_LOCAL_OOB, &smp->flags)) { |
| struct l2cap_chan *hchan = hdev->smp_data; |
| struct smp_dev *smp_dev; |
| |
| if (!hchan || !hchan->data) |
| return SMP_UNSPECIFIED; |
| |
| smp_dev = hchan->data; |
| |
| tfm_ecdh = smp_dev->tfm_ecdh; |
| } else { |
| tfm_ecdh = smp->tfm_ecdh; |
| } |
| |
| if (compute_ecdh_secret(tfm_ecdh, smp->remote_pk, smp->dhkey)) |
| return SMP_UNSPECIFIED; |
| |
| SMP_DBG("DHKey %32phN", smp->dhkey); |
| |
| set_bit(SMP_FLAG_REMOTE_PK, &smp->flags); |
| |
| smp->method = sc_select_method(smp); |
| |
| bt_dev_dbg(hdev, "selected method 0x%02x", smp->method); |
| |
| /* JUST_WORKS and JUST_CFM result in an unauthenticated key */ |
| if (smp->method == JUST_WORKS || smp->method == JUST_CFM) |
| hcon->pending_sec_level = BT_SECURITY_MEDIUM; |
| else |
| hcon->pending_sec_level = BT_SECURITY_FIPS; |
| |
| if (!crypto_memneq(debug_pk, smp->remote_pk, 64)) |
| set_bit(SMP_FLAG_DEBUG_KEY, &smp->flags); |
| |
| if (smp->method == DSP_PASSKEY) { |
| get_random_bytes(&hcon->passkey_notify, |
| sizeof(hcon->passkey_notify)); |
| hcon->passkey_notify %= 1000000; |
| hcon->passkey_entered = 0; |
| smp->passkey_round = 0; |
| if (mgmt_user_passkey_notify(hdev, &hcon->dst, hcon->type, |
| hcon->dst_type, |
| hcon->passkey_notify, |
| hcon->passkey_entered)) |
| return SMP_UNSPECIFIED; |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| return sc_passkey_round(smp, SMP_CMD_PUBLIC_KEY); |
| } |
| |
| if (smp->method == REQ_OOB) { |
| if (hcon->out) |
| smp_send_cmd(conn, SMP_CMD_PAIRING_RANDOM, |
| sizeof(smp->prnd), smp->prnd); |
| |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| |
| return 0; |
| } |
| |
| if (hcon->out) |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| |
| if (smp->method == REQ_PASSKEY) { |
| if (mgmt_user_passkey_request(hdev, &hcon->dst, hcon->type, |
| hcon->dst_type)) |
| return SMP_UNSPECIFIED; |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_CONFIRM); |
| set_bit(SMP_FLAG_WAIT_USER, &smp->flags); |
| return 0; |
| } |
| |
| /* The Initiating device waits for the non-initiating device to |
| * send the confirm value. |
| */ |
| if (conn->hcon->out) |
| return 0; |
| |
| err = smp_f4(smp->tfm_cmac, smp->local_pk, smp->remote_pk, smp->prnd, |
| 0, cfm.confirm_val); |
| if (err) |
| return SMP_UNSPECIFIED; |
| |
| smp_send_cmd(conn, SMP_CMD_PAIRING_CONFIRM, sizeof(cfm), &cfm); |
| SMP_ALLOW_CMD(smp, SMP_CMD_PAIRING_RANDOM); |
| |
| return 0; |
| } |
| |
| static int smp_cmd_dhkey_check(struct l2cap_conn *conn, struct sk_buff *skb) |
| { |
| struct smp_cmd_dhkey_check *check = (void *) skb->data; |
| struct l2cap_chan *chan = conn->smp; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_chan *smp = chan->data; |
| u8 a[7], b[7], *local_addr, *remote_addr; |
| u8 io_cap[3], r[16], e[16]; |
| int err; |
| |
| bt_dev_dbg(hcon->hdev, "conn %p", conn); |
| |
| if (skb->len < sizeof(*check)) |
| return SMP_INVALID_PARAMS; |
| |
| 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->prsp[1], 3); |
| } else { |
| local_addr = b; |
| remote_addr = a; |
| memcpy(io_cap, &smp->preq[1], 3); |
| } |
| |
| memset(r, 0, sizeof(r)); |
| |
| if (smp->method == REQ_PASSKEY || smp->method == DSP_PASSKEY) |
| put_unaligned_le32(hcon->passkey_notify, r); |
| else if (smp->method == REQ_OOB) |
| memcpy(r, smp->lr, 16); |
| |
| err = smp_f6(smp->tfm_cmac, smp->mackey, smp->rrnd, smp->prnd, r, |
| io_cap, remote_addr, local_addr, e); |
| if (err) |
| return SMP_UNSPECIFIED; |
| |
| if (crypto_memneq(check->e, e, 16)) |
| return SMP_DHKEY_CHECK_FAILED; |
| |
| if (!hcon->out) { |
| if (test_bit(SMP_FLAG_WAIT_USER, &smp->flags)) { |
| set_bit(SMP_FLAG_DHKEY_PENDING, &smp->flags); |
| return 0; |
| } |
| |
| /* Responder sends DHKey check as response to initiator */ |
| sc_dhkey_check(smp); |
| } |
| |
| sc_add_ltk(smp); |
| |
| if (hcon->out) { |
| hci_le_start_enc(hcon, 0, 0, smp->tk, smp->enc_key_size); |
| hcon->enc_key_size = smp->enc_key_size; |
| } |
| |
| return 0; |
| } |
| |
| static int smp_cmd_keypress_notify(struct l2cap_conn *conn, |
| struct sk_buff *skb) |
| { |
| struct smp_cmd_keypress_notify *kp = (void *) skb->data; |
| |
| bt_dev_dbg(conn->hcon->hdev, "value 0x%02x", kp->value); |
| |
| return 0; |
| } |
| |
| static int smp_sig_channel(struct l2cap_chan *chan, struct sk_buff *skb) |
| { |
| struct l2cap_conn *conn = chan->conn; |
| struct hci_conn *hcon = conn->hcon; |
| struct smp_chan *smp; |
| __u8 code, reason; |
| int err = 0; |
| |
| if (skb->len < 1) |
| return -EILSEQ; |
| |
| if (!hci_dev_test_flag(hcon->hdev, HCI_LE_ENABLED)) { |
| reason = SMP_PAIRING_NOTSUPP; |
| goto done; |
| } |
| |
| code = skb->data[0]; |
| skb_pull(skb, sizeof(code)); |
| |
| smp = chan->data; |
| |
| if (code > SMP_CMD_MAX) |
| goto drop; |
| |
|
|