Hi, On Thu, May 28, 2015 at 12:15 PM, Szymon Janc <szymon.janc@xxxxxxxxx> wrote: > Hi Ankur, > > On Thursday 28 of May 2015 18:07:48 Ankur Patel wrote: >> > Hi Ankur, >> > >> > On Thursday 28 of May 2015 16:47:09 Ankur Patel wrote: >> > > Hello Folks, >> > > >> > > I would like to Send Signed Write command to modify a characteristic >> > > on the Host. It failed into the Error: Failed to initiate write >> > > without response procedure >> > > >> > > Information on Controller (May be helpful): >> > > root@imx28evk:~# cat /proc/crypto >> > > name : ecb(aes) >> > > driver : ecb-aes-dcp >> > > module : kernel >> > > priority : 400 >> > > refcnt : 1 >> > > selftest : passed >> > > type : ablkcipher >> > > async : yes >> > > blocksize : 16 >> > > min keysize : 16 >> > > max keysize : 32 >> > > ivsize : 0 >> > > geniv : <default> >> > > >> > > root@imx28evk:~# btmgmt info >> > > Index list with 1 item >> > > hci0: Primary controller >> > > >> > > addr 1C:BA:8C:86:81:21 version 6 manufacturer 13 class 0x000000 >> > > supported settings: powered connectable fast-connectable >> > > >> > > discoverable bondable link-security ssp br/edr hs le advertising >> > > debug-keys privacy current settings: powered connectable discoverable >> > > bondable link-security br/edr le advertising name testbt >> > > >> > > short name >> > > >> > > root@imx28evk:~/tools# btgatt-client -d 00:1B:DC:07:2E:85 Connecting >> > > to device... Done Service Added - UUID: >> > > 00001800-0000-1000-8000-00805f9b34fb start: 0x0001 >> > > end: 0x000d Service Added - UUID: 00001801-0000-1000-8000-00805f9b34fb >> > > start: 0x0014 end: 0x0016 [GATT client]# GATT discovery procedures >> > > complete [GATT client]# ... >> > > [GATT client]# set-sign-key -c efcdab8967452301efcdab8967452301 [GATT >> > > client]# write-value -s -w 0xd 01 Failed to initiate write without >> > > response procedure >> > > >> > > I tried to trace the error as: >> > > bt_gatt_client_write_without_response(..) -> bt_att_send(..) -> >> > > create_att_send_op(..) -> encode_pdu(..) -> bt_crypto_sign_att(..) -> >> > > As >> > > att->crypto is NULL it returns false. >> > > >> > > I tried to check the reason for att->crypto to be NULL. Found that >> > > while initialization of the btgatt-client, under bt_crypto_new() -> >> > > crypto->ecb_aes = ecb_aes_setup();. It fails under ecb_aes_setup >> > >> > function. >> > >> > > From the output of /proc/crypto, the kernel has the support. I am >> > > wondering how to enable the crypto? >> > >> > Most likely following options are missing in your kernel configuration: >> > CONFIG_CRYPTO_CMAC >> > CONFIG_CRYPTO_USER_API >> > CONFIG_CRYPTO_USER_API_HASH >> > CONFIG_CRYPTO_USER_API_SKCIPHER >> >> It Worked!!. Thank you Szymon for quick response. >> >> Now I am able to send the Signed Write Command but without Authentication >> Signature. If I understood it correctly, 1) Set the Signature using [GATT >> client]# set-sign-key -c efcdab8967452301efcdab8967452301 2) Execute >> command: write-value -s -w 0xd 01 to send write command. >> >> I couldn't able to see the signature on the Sniffer. >> In addition on the Controller I see below output of root@imx28evk:~#Btmon: >> >> < ACL Data TX: Handle 1025 flags 0x00 dlen 20 >> >> >> [hci0] 2394.331806 ATT: Signed Write Command (0xd2) len 15 >> 0d 00 01 03 00 00 00 47 8a ec df 50 fc a5 ba .......G...P... > > This looks OK to me. > 0d 00 01 03 00 00 00 47 8a ec df 50 fc a5 ba > handle data signature > > > Check CoreSpec 4.2 Vol3, Part F, p. 3.4.5.4 (pdf page 2194) for details. We could probably improve btmon to print out the handle, data and signature separately. -- Luiz Augusto von Dentz -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
