This patch focus on handling signed write in ATT stack.
extend struct bt_att to store CSRK related information
and struct att_send_op to replace mtu by struct bt_att
for signature PDU need.
And add three CSRK related function for upper layer
Set CSRK into bt_att structure
Get CSRK into bt_att structure
Decide if CSRK is valid or not
---
src/shared/att-types.h | 3 ++
src/shared/att.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++--
src/shared/att.h | 13 +++++++
3 files changed, 114 insertions(+), 3 deletions(-)
diff --git a/src/shared/att-types.h b/src/shared/att-types.h
index b85c969..da8b6ae 100644
--- a/src/shared/att-types.h
+++ b/src/shared/att-types.h
@@ -25,6 +25,9 @@
#define BT_ATT_DEFAULT_LE_MTU 23
+/* Length of signature in write signed packet */
+#define BT_ATT_SIGNATURE_LEN 12
+
/* ATT protocol opcodes */
#define BT_ATT_OP_ERROR_RSP 0x01
#define BT_ATT_OP_MTU_REQ 0x02
diff --git a/src/shared/att.c b/src/shared/att.c
index a5cab45..b31eb9e 100644
--- a/src/shared/att.c
+++ b/src/shared/att.c
@@ -36,6 +36,7 @@
#include "lib/uuid.h"
#include "src/shared/att.h"
#include "src/shared/att-types.h"
+#include "src/shared/crypto.h"
#define ATT_MIN_PDU_LEN 1 /* At least 1 byte for the opcode. */
#define ATT_OP_CMD_MASK 0x40
@@ -77,6 +78,16 @@ struct bt_att {
bt_att_debug_func_t debug_callback;
bt_att_destroy_func_t debug_destroy;
void *debug_data;
+
+ struct bt_crypto *crypto;
+
+ bool valid_local_csrk;
+ uint8_t local_csrk[16];
+ uint32_t local_sign_cnt;
+
+ bool valid_remote_csrk;
+ uint8_t remote_csrk[16];
+ uint32_t remote_sign_cnt;
};
enum att_op_type {
@@ -176,6 +187,8 @@ struct att_send_op {
bt_att_response_func_t callback;
bt_att_destroy_func_t destroy;
void *user_data;
+
+ struct bt_att *att;
};
static void destroy_att_send_op(void *data)
@@ -277,6 +290,10 @@ static bool encode_pdu(struct att_send_op *op, const void *pdu,
uint16_t length, uint16_t mtu)
{
uint16_t pdu_len = 1;
+ struct bt_att *att = op->att;
+
+ if (op->opcode & ATT_OP_SIGNED_MASK)
+ pdu_len += BT_ATT_SIGNATURE_LEN;
if (length && pdu)
pdu_len += length;
@@ -293,17 +310,32 @@ static bool encode_pdu(struct att_send_op *op, const void *pdu,
if (pdu_len > 1)
memcpy(op->pdu + 1, pdu, length);
+ if (op->opcode & ATT_OP_SIGNED_MASK) {
+ if (bt_crypto_sign_att(att->crypto,
+ att->local_csrk,
+ op->pdu,
+ 1 + length,
+ att->local_sign_cnt,
+ &((uint8_t *) op->pdu)[1 + length]))
+ att->local_sign_cnt++;
+ else
+ return false;
+ }
+
return true;
}
-static struct att_send_op *create_att_send_op(uint8_t opcode, const void *pdu,
- uint16_t length, uint16_t mtu,
+static struct att_send_op *create_att_send_op(uint8_t opcode,
+ const void *pdu,
+ uint16_t length,
+ struct bt_att *att,
bt_att_response_func_t callback,
void *user_data,
bt_att_destroy_func_t destroy)
{
struct att_send_op *op;
enum att_op_type op_type;
+ uint16_t mtu = att->mtu;
if (length && !pdu)
return NULL;
@@ -334,6 +366,7 @@ static struct att_send_op *create_att_send_op(uint8_t opcode, const void *pdu,
op->callback = callback;
op->destroy = destroy;
op->user_data = user_data;
+ op->att = att;
if (!encode_pdu(op, pdu, length, mtu)) {
free(op);
@@ -698,6 +731,8 @@ struct bt_att *bt_att_new(int fd)
att->fd = fd;
+ att->local_sign_cnt = 0;
+ att->remote_sign_cnt = 0;
att->mtu = BT_ATT_DEFAULT_LE_MTU;
att->buf = malloc(att->mtu);
if (!att->buf)
@@ -707,6 +742,10 @@ struct bt_att *bt_att_new(int fd)
if (!att->io)
goto fail;
+ att->crypto = bt_crypto_new();
+ if (!att->crypto)
+ goto fail;
+
att->req_queue = queue_new();
if (!att->req_queue)
goto fail;
@@ -741,6 +780,7 @@ fail:
queue_destroy(att->write_queue, NULL);
queue_destroy(att->notify_list, NULL);
queue_destroy(att->disconn_list, NULL);
+ bt_crypto_unref(att->crypto);
io_destroy(att->io);
free(att->buf);
free(att);
@@ -931,7 +971,7 @@ unsigned int bt_att_send(struct bt_att *att, uint8_t opcode,
if (!att || !att->io)
return 0;
- op = create_att_send_op(opcode, pdu, length, att->mtu, callback,
+ op = create_att_send_op(opcode, pdu, length, att, callback,
user_data, destroy);
if (!op)
return 0;
@@ -1116,3 +1156,58 @@ bool bt_att_unregister_all(struct bt_att *att)
return true;
}
+
+bool bt_att_set_csrk(struct bt_att *att, enum bt_csrk_type type,
+ bool valid_csrk, uint8_t key[16])
+{
+
+ bool local = (type == LOCAL_CSRK);
+
+ if (!att)
+ return false;
+
+ if (local) {
+ att->valid_local_csrk = valid_csrk;
+ memcpy(att->local_csrk, key, 16);
+ } else {
+ att->valid_remote_csrk = valid_csrk;
+ memcpy(att->remote_csrk, key, 16);
+ }
+
+ return true;
+}
+
+bool bt_att_get_csrk(struct bt_att *att, enum bt_csrk_type type,
+ uint8_t key[16], uint32_t *sign_cnt)
+{
+ bool local = (type == LOCAL_CSRK);
+
+ if (!att)
+ return false;
+
+ if (local && att->valid_local_csrk) {
+ memcpy(key, att->local_csrk, 16);
+ *sign_cnt = att->local_sign_cnt;
+ } else if (!local && att->valid_remote_csrk) {
+ memcpy(key, att->remote_csrk, 16);
+ *sign_cnt = att->remote_sign_cnt;
+ } else {
+ return false;
+ }
+
+ return true;
+}
+
+bool bt_att_csrk_is_valid(struct bt_att *att, enum bt_csrk_type type)
+{
+ bool local = (type == LOCAL_CSRK);
+
+ if (!att)
+ return false;
+
+ if (local)
+ return att->valid_local_csrk;
+ else
+ return att->valid_remote_csrk;
+
+}
diff --git a/src/shared/att.h b/src/shared/att.h
index 1063021..9a54f64 100644
--- a/src/shared/att.h
+++ b/src/shared/att.h
@@ -26,6 +26,11 @@
#include "src/shared/att-types.h"
+enum bt_csrk_type {
+ LOCAL_CSRK,
+ REMOTE_CSRK,
+};
+
struct bt_att;
struct bt_att *bt_att_new(int fd);
@@ -76,3 +81,11 @@ unsigned int bt_att_register_disconnect(struct bt_att *att,
bool bt_att_unregister_disconnect(struct bt_att *att, unsigned int id);
bool bt_att_unregister_all(struct bt_att *att);
+
+bool bt_att_set_csrk(struct bt_att *att, enum bt_csrk_type type,
+ bool valid_csrk, uint8_t key[16]);
+
+bool bt_att_get_csrk(struct bt_att *att, enum bt_csrk_type type,
+ uint8_t key[16], uint32_t *sign_cnt);
+
+bool bt_att_csrk_is_valid(struct bt_att *att, enum bt_csrk_type type);
--
1.7.10.4
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