From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
This adds support for setting local and remote signing keys along with
a callback for fetching/updating signing counter.
---
src/shared/att.c | 102 ++++++++++++++++++++++++++++++++++++++++++++++++++++---
src/shared/att.h | 6 ++++
2 files changed, 104 insertions(+), 4 deletions(-)
diff --git a/src/shared/att.c b/src/shared/att.c
index 152f49c..5363907 100644
--- a/src/shared/att.c
+++ b/src/shared/att.c
@@ -36,6 +36,7 @@
#include "lib/bluetooth.h"
#include "lib/uuid.h"
#include "src/shared/att.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
@@ -52,6 +53,9 @@
#define BT_ERROR_ALREADY_IN_PROGRESS 0xfe
#define BT_ERROR_OUT_OF_RANGE 0xff
+/* Length of signature in write signed packet */
+#define BT_ATT_SIGNATURE_LEN 12
+
struct att_send_op;
struct bt_att {
@@ -85,6 +89,17 @@ struct bt_att {
bt_att_debug_func_t debug_callback;
bt_att_destroy_func_t debug_destroy;
void *debug_data;
+
+ struct bt_crypto *crypto;
+
+ struct sign_write_info *local_info;
+ struct sign_write_info *remote_info;
+};
+
+struct sign_write_info {
+ uint8_t key[16];
+ bt_att_counter_func_t counter;
+ void *user_data;
};
enum att_op_type {
@@ -184,6 +199,8 @@ 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)
@@ -266,6 +283,12 @@ 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;
+ struct sign_write_info *info;
+ uint32_t sign_cnt;
+
+ if (op->opcode & ATT_OP_SIGNED_MASK)
+ pdu_len += BT_ATT_SIGNATURE_LEN;
if (length && pdu)
pdu_len += length;
@@ -282,17 +305,36 @@ static bool encode_pdu(struct att_send_op *op, const void *pdu,
if (pdu_len > 1)
memcpy(op->pdu + 1, pdu, length);
- return true;
+ if (!(op->opcode & ATT_OP_SIGNED_MASK))
+ return true;
+
+ info = att->local_info;
+ if (!info)
+ goto fail;
+
+ if (!info->counter(&sign_cnt, info->user_data))
+ goto fail;
+
+ if ((bt_crypto_sign_att(att->crypto, info->key, op->pdu, 1 + length,
+ sign_cnt, &((uint8_t *) op->pdu)[1 + length])))
+ return true;
+
+fail:
+ free(op->pdu);
+ return false;
}
-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;
@@ -323,6 +365,7 @@ 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);
@@ -810,6 +853,7 @@ static void bt_att_free(struct bt_att *att)
destroy_att_send_op(att->pending_ind);
io_destroy(att->io);
+ bt_crypto_unref(att->crypto);
queue_destroy(att->req_queue, NULL);
queue_destroy(att->ind_queue, NULL);
@@ -841,6 +885,8 @@ struct bt_att *bt_att_new(int fd)
att->fd = fd;
+ att->local_info = NULL;
+ att->remote_info = NULL;
att->mtu = BT_ATT_DEFAULT_LE_MTU;
att->buf = malloc(att->mtu);
if (!att->buf)
@@ -850,6 +896,10 @@ 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;
@@ -964,6 +1014,16 @@ bool bt_att_set_mtu(struct bt_att *att, uint16_t mtu)
if (!buf)
return false;
+ if (att->local_info) {
+ free(att->local_info);
+ att->local_info = NULL;
+ }
+
+ if (att->remote_info) {
+ free(att->remote_info);
+ att->remote_info = NULL;
+ }
+
free(att->buf);
att->mtu = mtu;
@@ -1047,7 +1107,7 @@ 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;
@@ -1307,3 +1367,37 @@ bool bt_att_set_sec_level(struct bt_att *att, int level)
return true;
}
+
+static bool sign_info_set_key(struct sign_write_info **info, uint8_t key[16],
+ bt_att_counter_func_t func, void *user_data)
+{
+ if (!(*info)) {
+ *info = new0(struct sign_write_info, 1);
+ if (!(*info))
+ return false;
+ }
+
+ (*info)->counter = func;
+ (*info)->user_data = user_data;
+ memcpy((*info)->key, key, 16);
+
+ return true;
+}
+
+bool bt_att_set_local_key(struct bt_att *att, uint8_t sign_key[16],
+ bt_att_counter_func_t func, void *user_data)
+{
+ if (!att)
+ return false;
+
+ return sign_info_set_key(&att->local_info, sign_key, func, user_data);
+}
+
+bool bt_att_set_remote_key(struct bt_att *att, uint8_t sign_key[16],
+ bt_att_counter_func_t func, void *user_data)
+{
+ if (!att)
+ return false;
+
+ return sign_info_set_key(&att->remote_info, sign_key, func, user_data);
+}
diff --git a/src/shared/att.h b/src/shared/att.h
index 5256ff9..a440aaf 100644
--- a/src/shared/att.h
+++ b/src/shared/att.h
@@ -46,6 +46,7 @@ typedef void (*bt_att_debug_func_t)(const char *str, void *user_data);
typedef void (*bt_att_timeout_func_t)(unsigned int id, uint8_t opcode,
void *user_data);
typedef void (*bt_att_disconnect_func_t)(int err, void *user_data);
+typedef bool (*bt_att_counter_func_t)(uint32_t *sign_cnt, void *user_data);
bool bt_att_set_debug(struct bt_att *att, bt_att_debug_func_t callback,
void *user_data, bt_att_destroy_func_t destroy);
@@ -84,3 +85,8 @@ bool bt_att_unregister_all(struct bt_att *att);
int bt_att_get_sec_level(struct bt_att *att);
bool bt_att_set_sec_level(struct bt_att *att, int level);
+
+bool bt_att_set_local_key(struct bt_att *att, uint8_t sign_key[16],
+ bt_att_counter_func_t func, void *user_data);
+bool bt_att_set_remote_key(struct bt_att *att, uint8_t sign_key[16],
+ bt_att_counter_func_t func, void *user_data);
--
2.1.0
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