Hi Matias, Actually, I asked on IRC, and got some help there and the issue was with the adapter not being properly powered up on my Linux distro. In bluetoothctl, if I do power off and then power on, scan on/off, then the pairing works as expected. Thanks for your help Axelle. On Thu, Jul 11, 2019 at 10:42 PM Matias Karhumaa <matias.karhumaa@xxxxxxxxx> wrote: > > Hi Axelle, > > On Thu, Jul 11, 2019 at 02:47:31PM +0200, Axelle wrote: > > I am trying to pair with a BLE device from a RPI device. The first few > > packets seem fine (Pairing Request, Pairing Response, LE Start > > Encryption, Signing Information...) but in the end I get a "Pairing > > Failed" SMP packet, with reason "Unspecified reason" :( > > > > Any explanation what could be the ... reason ;) and how to solve this please? > > > > Thanks! > > What kernel version you are running on RPI? How do you initiate pairing? > There seems to be something weird going on in this btmon trace. > > > > > PS. This is the btmon log: > > > > < HCI Command: Reset (0x03|0x0003) plen 0 > > [hci0] 298.154979 > > > HCI Event: Command Complete (0x0e) plen 4 [hci0] 298.157882 > > Reset (0x03|0x0003) ncmd 1 > > Status: Success (0x00) > > < HCI Command: Set Event Filter (0x03|0x0005) plen 1 > > [hci0] 298.171262 > > Type: Clear All Filters (0x00) > > > HCI Event: Command Complete (0x0e) plen 4 [hci0] 298.171657 > > Set Event Filter (0x03|0x0005) ncmd 1 > > Status: Success (0x00) > > < HCI Command: Write Connection Accept Timeout (0x03|0x0016) plen 2 > > [hci0] 298.185592 > > Timeout: 20000.000 msec (0x7d00) > > > HCI Event: Command Complete (0x0e) plen 4 [hci0] 298.186005 > > Write Connection Accept Timeout (0x03|0x0016) ncmd 1 > > Status: Success (0x00) > > < HCI Command: Set Event Mask (0x03|0x0001) plen 8 > > [hci0] 298.198904 > > Mask: 0x3dbff807fffbffff > > Inquiry Complete > > Inquiry Result > > Connection Complete > > Connection Request > > Disconnection Complete > > Authentication Complete > > Remote Name Request Complete > > Encryption Change > > Change Connection Link Key Complete > > Master Link Key Complete > > Read Remote Supported Features Complete > > Read Remote Version Information Complete > > QoS Setup Complete > > Command Complete > > Command Status > > Hardware Error > > Flush Occurred > > Role Change > > Mode Change > > Return Link Keys > > PIN Code Request > > Link Key Request > > Link Key Notification > > Loopback Command > > Data Buffer Overflow > > Max Slots Change > > Read Clock Offset Complete > > Connection Packet Type Changed > > QoS Violation > > Page Scan Mode Change > > Page Scan Repetition Mode Change > > Flow Specification Complete > > Inquiry Result with RSSI > > Read Remote Extended Features Complete > > Synchronous Connection Complete > > Synchronous Connection Changed > > Sniff Subrating > > Extended Inquiry Result > > Encryption Key Refresh Complete > > IO Capability Request > > IO Capability Request Reply > > User Confirmation Request > > User Passkey Request > > Remote OOB Data Request > > Simple Pairing Complete > > Link Supervision Timeout Changed > > Enhanced Flush Complete > > User Passkey Notification > > Keypress Notification > > Remote Host Supported Features Notification > > LE Meta > > > HCI Event: Command Complete (0x0e) plen 4 [hci0] 298.199255 > > Set Event Mask (0x03|0x0001) ncmd 1 > > Status: Success (0x00) > > < HCI Command: Write LE Host Supported (0x03|0x006d) plen 2 > > [hci0] 298.214150 > > Supported: 0x01 > > Simultaneous: 0x01 > > > HCI Event: Command Complete (0x0e) plen 4 [hci0] 298.214499 > > Write LE Host Supported (0x03|0x006d) ncmd 1 > > Status: Success (0x00) > > < HCI Command: LE Create Connection (0x08|0x000d) plen 25 > > [hci0] 302.516667 > > Scan interval: 60.000 msec (0x0060) > > Scan window: 30.000 msec (0x0030) > > Filter policy: White list is not used (0x00) > > Peer address type: Random (0x01) > > Peer address: D2:A7:4C:76:F3:E0 (Static) > > Own address type: Public (0x00) > > Min connection interval: 50.00 msec (0x0028) > > Max connection interval: 70.00 msec (0x0038) > > Connection latency: 0x0000 > > Supervision timeout: 420 msec (0x002a) > > Min connection length: 0.000 msec (0x0000) > > Max connection length: 0.000 msec (0x0000) > > > HCI Event: Command Status (0x0f) plen 4 [hci0] 302.517237 > > LE Create Connection (0x08|0x000d) ncmd 1 > > Status: Success (0x00) > > > HCI Event: LE Meta Event (0x3e) plen 19 [hci0] 302.658079 > > LE Connection Complete (0x01) > > Status: Success (0x00) > > Handle: 64 > > Role: Master (0x00) > > Peer address type: Random (0x01) > > Peer address: D2:A7:4C:76:F3:E0 (Static) > > Connection interval: 67.50 msec (0x0036) > > Connection latency: 0.00 msec (0x0000) > > Supervision timeout: 420 msec (0x002a) > > Master clock accuracy: 0x00 > > > ACL Data RX: Handle 64 flags 0x02 dlen 16 [hci0] 307.789579 > > LE L2CAP: Connection Parameter Update Request (0x12) ident 2 len 8 > > Min interval: 6 > > Max interval: 12 > > Slave latency: 0 > > Timeout multiplier: 400 > > < HCI Command: LE Connection Update (0x08|0x0013) plen 14 > > [hci0] 307.813788 > > Handle: 64 > > Min connection interval: 7.50 msec (0x0006) > > Max connection interval: 15.00 msec (0x000c) > > Connection latency: 0x0000 > > Supervision timeout: 4000 msec (0x0190) > > Min connection length: 0.000 msec (0x0000) > > Max connection length: 0.000 msec (0x0000) > > > HCI Event: Command Status (0x0f) plen 4 [hci0] 307.814226 > > LE Connection Update (0x08|0x0013) ncmd 1 > > Status: Success (0x00) > > < ACL Data TX: Handle 64 flags 0x00 dlen 10 > > [hci0] 307.837601 > > LE L2CAP: Connection Parameter Update Response (0x13) ident 0 len 2 > > Result: Connection Parameters accepted (0x0000) > > > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 308.157176 > > Num handles: 1 > > Handle: 64 > > Count: 1 > > > HCI Event: LE Meta Event (0x3e) plen 10 [hci0] 308.272198 > > LE Connection Update Complete (0x03) > > Status: Success (0x00) > > Handle: 64 > > Connection interval: 15.00 msec (0x000c) > > Connection latency: 0.00 msec (0x0000) > > Supervision timeout: 4000 msec (0x0190) > > < ACL Data TX: Handle 64 flags 0x00 dlen 11 > > [hci0] 315.133782 > > SMP: Pairing Request (0x01) len 6 > > IO capability: KeyboardOnly (0x02) > > OOB data: Authentication data not present (0x00) > > Authentication requirement: Bonding, MITM, Legacy, No Keypresses (0x05) > > Max encryption key size: 16 > > Initiator key distribution: EncKey Sign (0x05) > > Responder key distribution: EncKey Sign (0x05) > > > ACL Data RX: Handle 64 flags 0x02 dlen 11 [hci0] 315.157207 > > SMP: Pairing Response (0x02) len 6 > > IO capability: NoInputNoOutput (0x03) > > OOB data: Authentication data not present (0x00) > > Authentication requirement: Bonding, No MITM, Legacy, No > > Keypresses (0x01) > > Max encryption key size: 16 > > Initiator key distribution: Sign (0x04) > > Responder key distribution: EncKey (0x01) > > < HCI Command: Read BD ADDR (0x04|0x0009) plen 0 > > [hci0] 315.165422 > > > HCI Event: Command Complete (0x0e) plen 10 [hci0] 315.165792 > > Read BD ADDR (0x04|0x0009) ncmd 1 > > Status: Success (0x00) > > Address: B8:27:EB:15:50:70 (Raspberry Pi Foundation) > > < ACL Data TX: Handle 64 flags 0x00 dlen 21 > > [hci0] 315.183781 > > SMP: Pairing Confirm (0x03) len 16 > > Confim value: 12e170d20c0bb8beb6d7c59bb006acd0 > > > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 315.187419 > > Num handles: 1 > > Handle: 64 > > Count: 2 > > > ACL Data RX: Handle 64 flags 0x02 dlen 21 [hci0] 315.202330 > > SMP: Pairing Confirm (0x03) len 16 > > Confim value: 6e0be0cc5a8f08ffc98a88c25167aa2f > > < ACL Data TX: Handle 64 flags 0x00 dlen 21 > > [hci0] 315.219695 > > SMP: Pairing Random (0x04) len 16 > > Random value: 25498f1cc873d7450460df3b5ce2ab7e > > > ACL Data RX: Handle 64 flags 0x02 dlen 21 [hci0] 315.247316 > > SMP: Pairing Random (0x04) len 16 > > Random value: 9e7769acf6f4c19706f9abde25d4749f > > < HCI Command: LE Start Encryption (0x08|0x0019) plen 28 > > [hci0] 315.256836 > > Handle: 64 > > Random number: 0x0000000000000000 > > Encrypted diversifier: 0x0000 > > Long term key: 7689a6b5371537b24f2c7c7805688df6 > > > HCI Event: Command Status (0x0f) plen 4 [hci0] 315.257310 > > LE Start Encryption (0x08|0x0019) ncmd 1 > > Status: Success (0x00) > > > HCI Event: Encryption Change (0x08) plen 4 [hci0] 315.337302 > > Status: Success (0x00) > > Handle: 64 > > Encryption: Enabled with AES-CCM (0x01) > > > ACL Data RX: Handle 64 flags 0x02 dlen 21 [hci0] 315.367776 > > SMP: Encryption Information (0x06) len 16 > > Long term key: b22ef80c481a8b4929e7159e0c2b0ba3 > > > ACL Data RX: Handle 64 flags 0x02 dlen 15 [hci0] 315.397264 > > SMP: Master Identification (0x07) len 10 > > EDIV: 0x02ee > > Rand: 0x0720e828075f93eb > > > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 315.407288 > > Num handles: 1 > > Handle: 64 > > Count: 1 > > < ACL Data TX: Handle 64 flags 0x00 dlen 21 > > [hci0] 315.416056 > > SMP: Encryption Information (0x06) len 16 > > Long term key: ffeeddccbbaa99887766554433221100 > > < ACL Data TX: Handle 64 flags 0x00 dlen 15 > > [hci0] 315.425880 > > SMP: Master Identification (0x07) len 10 > > EDIV: 0x000c > > Rand: 0x8877665544332211 > > This looks weird here: to my understanding your RPI should not send > Encryption Information and Master Identification at all because only > Sign bit is set in Pairing Response's Initiator key distribution flags. > > It is possible that the other device does not like that and sends then > Pairing Failed. > > Also Long Term Key and Rand values are somewhat suspicious and not > random as they should. > > > < ACL Data TX: Handle 64 flags 0x00 dlen 21 > > [hci0] 315.433926 > > SMP: Signing Information (0x0a) len 16 > > Signature key: ffeeddccbbaa99887766554433221100 > > > ACL Data RX: Handle 64 flags 0x02 dlen 6 [hci0] 315.442266 > > SMP: Pairing Failed (0x05) len 1 > > Reason: Unspecified reason (0x08) > > > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 315.442543 > > Num handles: 1 > > Handle: 64 > > Count: 2 > > > HCI Event: Number of Completed Packets (0x13) plen 5 [hci0] 315.532771 > > Num handles: 1 > > Handle: 64 > > Count: 1 > > > HCI Event: Disconnect Complete (0x05) plen 4 [hci0] 315.532868 > > Status: Success (0x00) > > Handle: 64 > > Reason: Remote User Terminated Connection (0x13) > > Best regards, > Matias
