Re: tpm_tis TPM2.0 not detected on cold boot

From: Michael Niewöhner
Date: Thu Jan 03 2019 - 10:48:00 EST


On Thu, 2019-01-03 at 17:04 +0200, Jarkko Sakkinen wrote:
> On Thu, Jan 03, 2019 at 02:38:11PM +0100, Michael NiewÃhner wrote:
> > On Thu, 2019-01-03 at 15:27 +0200, Jarkko Sakkinen wrote:
> > > On Sun, Dec 23, 2018 at 12:55:12PM +0100, Michael NiewÃhner wrote:
> > > > There is another issue but I don't know if both are related. Maybe
> > > > that's
> > > > just a
> > > > timing issue...
> > > >
> > > > root@debian:~# dd if=/dev/hwrng bs=1 count=1
> > > > dd: error reading '/dev/hwrng': Operation not permitted
> > > > 0+0 records in
> > > > 0+0 records out
> > > > 0 bytes copied, 0.755958 s, 0.0 kB/s
> > > > root@debian:~# dd if=/dev/hwrng bs=1 count=1 | xxd; dd if=/dev/hwrng
> > > > bs=1
> > > > count=1 | xxd
> > > > dd: error reading '/dev/hwrng': Operation not permitted
> > > > 0+0 records in
> > > > 0+0 records out
> > > > 0 bytes copied, 0.755697 s, 0.0 kB/s
> > > > 1+0 records in
> > > > 1+0 records out
> > > > 00000000: 52 R
> > > > 1 byte copied, 0.0106268 s, 0.1 kB/s
> > > >
> > > >
> > > > Michael
> > >
> > > What does /sys/devices/virtual/misc/hw_random/rng_current show?
> > >
> > > Did run commands as a sanity check on my laptop and seem to work.
> > >
> > > /Jarkko
> >
> > rng_current says "tpm-rng-0", which should be correct
>
> Is /dev/tpm0 accessible and usable?
>
> /Jarkko

No, it does not seem to work:

root@debian:~# tpm_version
Tspi_Context_Connect failed: 0x00003011 - layer=tsp, code=0011 (17),
Communication failure
root@debian:~# tcsd -f
TCSD TDDL ioctl: (25) Inappropriate ioctl for device
TCSD TDDL Falling back to Read/Write device support.
TCSD TDDL ERROR: write to device /dev/tpm0 failed: Operation not permitted
TCSD TCS ERROR: TCS GetCapability failed with result = 0x1087
root@debian:~# stat /dev/tpm0
File: /dev/tpm0
Size: 0 Blocks: 0 IO Block: 4096 character special
file
Device: 6h/6d Inode: 1114 Links: 1 Device type: a,e0
Access: (0600/crw-------) Uid: ( 104/ tss) Gid: ( 112/ tss)
Access: 2019-01-03 16:39:20.627635333 +0100
Modify: 2019-01-03 16:39:20.627635333 +0100
Change: 2019-01-03 16:39:20.627635333 +0100
Birth: -

Michael