Luiz Augusto von Dentz Wrote: >have you tried >just running bluetoothctl to see if that makes it work? Yes that was the point of my title. In 5.4 Linux I do not need bluetoothctl running, but in 5.10 I do. This is a BLE GATT Client. I do not save anything involving credentials, there are none for me to save. I always remove the device on disconnect because there are too many devices. Connections are short lived. There is nothing to do for pairing except to exchange public keys. I cannot let bluetoothctl run because I have an embedded device, and scans by bluetoothctl add to the CPU load, and I cannot turn scan off because I need to know when a new BLE device advertises. Devices are not advertising when there is nothing for me to do. I have a filter, but bluetoothctl ignores the filter, but my application works fine with the filter. So if this is a new requirement in 5.10 Linux, I need to add an agent to my application. Looking at the agent documentation: https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc/agent-api.txt Agent-api.txt says: >It is not required by an application to register >an agent. If an application does chooses to not >register an agent, the default agent is used. This >is on most cases a good idea. Only application >like a pairing wizard should register their own >agent. Is this documentation obsolete as of 5.10? When I run bluetoothctl, nothing happens in bluetoothctl during pairing (which is what I would expect). It just makes things work. If I create an agent, it should be a trivial one with NoInputNoOutput set. There is no pin. There is nothing to do. Right now I am trying to determine what exactly needs to be done. <html><head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body><div style="font-family:Arial,Helvetica,sans-serif; font-size:12pt; color:rgb(0,0,0)"><br></div><hr tabindex="-1" style="display:inline-block; width:98%"><div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" color="#000000" style="font-size:11pt"><b>From:</b> Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx><br><b>Sent:</b> Tuesday, August 30, 2022 5:28 PM<br><b>To:</b> John Klug <John.Klug@xxxxxxxxxxxxx><br><b>Cc:</b> Linux-Bluetooth MailingList <linux-bluetooth@xxxxxxxxxxxxxxx><br><b>Subject:</b> Re: What could cause pairing to fail when bluetoothctl is not running?</font> <div> </div></div><div class="BodyFragment"><font size="2"><span style="font-size:11pt"><div class="PlainText">Hi John,<br><br>On Tue, Aug 30, 2022 at 3:22 PM John Klug <John.Klug@xxxxxxxxxxxxx> wrote:<br>><br>> I am now looking at what is going on with a sniffer. For some reason in 5.10, the AuthReq always comes from the slave (BlueZ is the master, GATT client):<br>><br>> 5.10 kernel which fails, leaving out empty PDU, L2CAP Fragments, etc. This sequence is reproducible.<br>><br>> Sent slave CONNECT_IND<br>> Rcvd Security Request: AuthReq: Bonding, SecureConnection<br>> Sent Pairing Failed: Pairing not Supported<br>> Sent Pairing Failed: Pairing not Supported<br>> Rcvd Exchange MTU Response ...<br>> Sent Pairing Request: AuthReq: No Bonding, SecureConnection | Initiator Key(s): <none> | Responder key(s) IRK<br>> Sent Control Opcode LL_LENGTH_RSP<br>> Rcvd Pairing Response: AuthReq: No Bonding, SecureConnection | Initiator Key(s): <none> | Responder key(s)<br>> Sent Pairing Public Key<br>> Sent Read By Type Request, Sever Supported Features, Handles: ...<br>> Recvd Pairing Public Key<br>> Rcvd Pairing Confirm<br>> Rcvd Error Response - Attribute Not Found, Handle: 0x0001 (Unknown)<br>> Sent Pairing Random<br>> Sent Read by Group Type Request, Gatt ...<br>> Rcvd Pairing Random<br>> Send Pairing Failed: Numeric Comparison Failed<br>><br>> The 5.4 kernel always works, but BlueZ/Linux sends the first AuthReq:<br>><br>> Sent Slave CONNECT_IND<br>> Sent Pairing Request: AuthReq: No Bonding, SecureConnection | Initiator Key(s): <none> | Responder key(s)<br>> Rcvd Pairing Response: AuthReq: No Bonding, SecureConnection | Initiator Key(s): <none> | Responder key(s)<br>> Sent Read By Type Request, Sever Supported Features, Handles: ...<br>> Rcvd Pairing Response: AuthReq: No Bonding, SecureConnection | Initiator Key(s): <none> | Responder<br>> Sent Read by Group Type Request, Gatt ..<br>> Rcvd Pairing Confirm<br>> Rcvd Read by Group Type Response, Attribute ..<br>> Sent Pairing Random<br>> Sent Read by Group Type Request, Gatt ..<br>> Rcvd Pairing Random<br>> Sent Pairing DHKey Check<br>><br>> Should the program be sending a Pair using the Device API? Is there something else to cause the public key exchange? In the 5.4 case, the "Paired" property is always being set by the Device API.<br><br>Either way you need a pairing agent in case the device for some reason<br>removes its link key and then you need to repair, besides the agent<br>also does authorization when the device is not trusted, have you tried<br>just running bluetoothctl to see if that makes it work?<br><br>-- <br>Luiz Augusto von Dentz<br></div></span></font></div></body></html>
