[PATCH 3/5] Parse pin codes starting with '$' as hexadecimal encoded strings

[PATCH 3/5] Parse pin codes starting with '$' as hexadecimal encoded strings

[David Herrmann]

If a pin code is retrieved from an agent and the first character is
a dollar sign '$', then the pin is decoded as following:
 - The first character (dollar sign) is stripped from the pin
 - The rest is parsed as hexadecimal numbers, where each two characters
  will be converted into a one byte integer. If an odd number of
  characters follows, then the last character is stripped. Empty
  pins are valid. Parser is case insensitive.
Pins not starting with '$' are parsed as usual.

For instance:
 pin: $0A3e005067
is decoded into a 5 byte pin:
 decoded: 0x0a 0x3e 0x00 0x50 0x67
---
 src/event.c |   33 +++++++++++++++++++++++++++++++--
 1 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/src/event.c b/src/event.c
index c238392..147a29b 100644
--- a/src/event.c
+++ b/src/event.c
@@ -101,12 +101,41 @@ static gboolean get_adapter_and_device(bdaddr_t *src, bdaddr_t *dst,
  *
  *****************************************************************/
 
+static size_t decode_hex(const char *pin, char *out)
+{
+	size_t i;
+
+	for (i = 0; i < 16 && pin[i * 2] && pin[i * 2 + 1]; i++)
+		sscanf(&pin[i * 2], "%02hhX", &out[i]);
+
+	return i;
+}
+
+static size_t decode_pin(const char *pin, char *out)
+{
+	size_t len;
+
+	if (!pin)
+		return 0;
+
+	if (pin[0] == '$') {
+		len = decode_hex(&pin[1], out);
+	} else {
+		len = strnlen(pin, 16);
+		memcpy(out, pin, len);
+	}
+
+	return len;
+}
+
 static void pincode_cb(struct agent *agent, DBusError *derr,
 				const char *pincode, struct btd_device *device)
 {
 	struct btd_adapter *adapter = device_get_adapter(device);
 	bdaddr_t dba;
 	int err;
+	size_t len;
+	char rawpin[16];
 
 	device_get_address(device, &dba);
 
@@ -117,8 +146,8 @@ static void pincode_cb(struct agent *agent, DBusError *derr,
 		return;
 	}
 
-	err = btd_adapter_pincode_reply(adapter, &dba, pincode,
-						pincode ? strlen(pincode) : 0);
+	len = decode_pin(pincode, rawpin);
+	err = btd_adapter_pincode_reply(adapter, &dba, rawpin, len);
 	if (err < 0)
 		goto fail;
 
-- 
1.7.5

[PATCH 1/5] Add length argument to hci pincode reply

[David Herrmann]

This adds a new "length" argument to the hci pincode reply to allow
sending binary pins including \0 characters.
---
 plugins/hciops.c  |   10 +++++-----
 plugins/mgmtops.c |    9 ++++-----
 src/adapter.c     |    3 ++-
 src/adapter.h     |    3 ++-
 4 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/plugins/hciops.c b/plugins/hciops.c
index 2c49e35..b125699 100644
--- a/plugins/hciops.c
+++ b/plugins/hciops.c
@@ -3415,7 +3415,8 @@ static int hciops_remove_bonding(int index, bdaddr_t *bdaddr)
 	return 0;
 }
 
-static int hciops_pincode_reply(int index, bdaddr_t *bdaddr, const char *pin)
+static int hciops_pincode_reply(int index, bdaddr_t *bdaddr, const char *pin,
+								size_t pin_len)
 {
 	struct dev_info *dev = &devs[index];
 	char addr[18];
@@ -3426,14 +3427,13 @@ static int hciops_pincode_reply(int index, bdaddr_t *bdaddr, const char *pin)
 
 	if (pin) {
 		pin_code_reply_cp pr;
-		size_t len = strlen(pin);
 
-		dev->pin_length = len;
+		dev->pin_length = pin_len;
 
 		memset(&pr, 0, sizeof(pr));
 		bacpy(&pr.bdaddr, bdaddr);
-		memcpy(pr.pin_code, pin, len);
-		pr.pin_len = len;
+		memcpy(pr.pin_code, pin, pin_len);
+		pr.pin_len = pin_len;
 		err = hci_send_cmd(dev->sk, OGF_LINK_CTL,
 						OCF_PIN_CODE_REPLY,
 						PIN_CODE_REPLY_CP_SIZE, &pr);
diff --git a/plugins/mgmtops.c b/plugins/mgmtops.c
index 9e1cfac..ce0ec2d 100644
--- a/plugins/mgmtops.c
+++ b/plugins/mgmtops.c
@@ -494,7 +494,8 @@ static void mgmt_connect_failed(int sk, uint16_t index, void *buf, size_t len)
 	btd_event_bonding_complete(&info->bdaddr, &ev->bdaddr, ev->status);
 }
 
-static int mgmt_pincode_reply(int index, bdaddr_t *bdaddr, const char *pin)
+static int mgmt_pincode_reply(int index, bdaddr_t *bdaddr, const char *pin,
+								size_t pin_len)
 {
 	char buf[MGMT_HDR_SIZE + sizeof(struct mgmt_cp_pin_code_reply)];
 	struct mgmt_hdr *hdr = (void *) buf;
@@ -502,7 +503,7 @@ static int mgmt_pincode_reply(int index, bdaddr_t *bdaddr, const char *pin)
 	char addr[18];
 
 	ba2str(bdaddr, addr);
-	DBG("index %d addr %s pin %s", index, addr, pin ? pin : "<none>");
+	DBG("index %d addr %s pinlen %lu", index, addr, pin_len);
 
 	memset(buf, 0, sizeof(buf));
 
@@ -519,9 +520,7 @@ static int mgmt_pincode_reply(int index, bdaddr_t *bdaddr, const char *pin)
 		buf_len = sizeof(*hdr) + sizeof(*cp);
 	} else {
 		struct mgmt_cp_pin_code_reply *cp;
-		size_t pin_len;
 
-		pin_len = strlen(pin);
 		if (pin_len > 16)
 			return -EINVAL;
 
@@ -569,7 +568,7 @@ static void mgmt_pin_code_request(int sk, uint16_t index, void *buf, size_t len)
 	err = btd_event_request_pin(&info->bdaddr, &ev->bdaddr);
 	if (err < 0) {
 		error("btd_event_request_pin: %s", strerror(-err));
-		mgmt_pincode_reply(index, &ev->bdaddr, NULL);
+		mgmt_pincode_reply(index, &ev->bdaddr, NULL, 0);
 	}
 }
 
diff --git a/src/adapter.c b/src/adapter.c
index f068335..b7016c4 100644
--- a/src/adapter.c
+++ b/src/adapter.c
@@ -3545,7 +3545,8 @@ int btd_adapter_remove_bonding(struct btd_adapter *adapter, bdaddr_t *bdaddr)
 int btd_adapter_pincode_reply(struct btd_adapter *adapter, bdaddr_t *bdaddr,
 							const char *pin)
 {
-	return adapter_ops->pincode_reply(adapter->dev_id, bdaddr, pin);
+	return adapter_ops->pincode_reply(adapter->dev_id, bdaddr, pin,
+							pin ? strlen(pin) : 0);
 }
 
 int btd_adapter_confirm_reply(struct btd_adapter *adapter, bdaddr_t *bdaddr,
diff --git a/src/adapter.h b/src/adapter.h
index 9406b9b..e08068c 100644
--- a/src/adapter.h
+++ b/src/adapter.h
@@ -201,7 +201,8 @@ struct btd_adapter_ops {
 	int (*read_local_features) (int index, uint8_t *features);
 	int (*disconnect) (int index, bdaddr_t *bdaddr);
 	int (*remove_bonding) (int index, bdaddr_t *bdaddr);
-	int (*pincode_reply) (int index, bdaddr_t *bdaddr, const char *pin);
+	int (*pincode_reply) (int index, bdaddr_t *bdaddr, const char *pin,
+							size_t pin_len);
 	int (*confirm_reply) (int index, bdaddr_t *bdaddr, gboolean success);
 	int (*passkey_reply) (int index, bdaddr_t *bdaddr, uint32_t passkey);
 	int (*enable_le) (int index);
-- 
1.7.5

[PATCH 3/5] Parse pin codes starting with '$' as hexadecimal encoded strings

[David Herrmann]

If a pin code is retrieved from an agent and the first character is
a dollar sign '$', then the pin is decoded as following:
 - The first character (dollar sign) is stripped from the pin
 - The rest is parsed as hexadecimal numbers, where each two characters
   will be converted into a one byte integer. If an odd number of
   characters follows, then the last character is stripped. Empty
   pins are valid. Parser is case insensitive.
Pins not starting with '$' are parsed as usual.

For instance:
 pin: $0A3e005067
is decoded into a 5 byte pin:
 decoded: 0x0a 0x3e 0x00 0x50 0x67
---
 src/event.c |   45 +++++++++++++++++++++++++++++++++++++++++++--
 1 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/src/event.c b/src/event.c
index c238392..b0318de 100644
--- a/src/event.c
+++ b/src/event.c
@@ -101,12 +101,53 @@ static gboolean get_adapter_and_device(bdaddr_t *src, bdaddr_t *dst,
  *
  *****************************************************************/
 
+static uint8_t hex2dec(uint8_t c)
+{
+	if (c >= '0' && c <= '9')
+		return  c - '0';
+	else if (c >= 'A' && c <= 'F')
+		return c - 'A' + 10;
+	else if (c >= 'a' && c <= 'f')
+		return c - 'a' + 10;
+	else
+		return 0;
+}
+
+static size_t decode_hex(const char *pin, char *out)
+{
+	size_t i;
+
+	for (i = 0; i < 16 && pin[i * 2] && pin[i * 2 + 1]; i++)
+		out[i] = hex2dec(pin[i * 2]) * 16 + hex2dec(pin[i * 2 + 1]);
+
+	return i;
+}
+
+static size_t decode_pin(const char *pin, char *out)
+{
+	size_t len;
+
+	if (!pin)
+		return 0;
+
+	if (pin[0] == '$') {
+		len = decode_hex(&pin[1], out);
+	} else {
+		len = strnlen(pin, 16);
+		memcpy(out, pin, len);
+	}
+
+	return len;
+}
+
 static void pincode_cb(struct agent *agent, DBusError *derr,
 				const char *pincode, struct btd_device *device)
 {
 	struct btd_adapter *adapter = device_get_adapter(device);
 	bdaddr_t dba;
 	int err;
+	size_t len;
+	char rawpin[16];
 
 	device_get_address(device, &dba);
 
@@ -117,8 +158,8 @@ static void pincode_cb(struct agent *agent, DBusError *derr,
 		return;
 	}
 
-	err = btd_adapter_pincode_reply(adapter, &dba, pincode,
-						pincode ? strlen(pincode) : 0);
+	len = decode_pin(pincode, rawpin);
+	err = btd_adapter_pincode_reply(adapter, &dba, rawpin, len);
 	if (err < 0)
 		goto fail;
 
-- 
1.7.5