[tpm2] Re: tpm2-pytss connect to dockerized swtpm

Hi Erik,

Thank you very much! The suggestion about the swtpm IP address was correct!

Best regards,
Henry

-----Ursprüngliche Nachricht-----
Von: Erik <who+01tpm(a)cnackers.org> 
Gesendet: Mittwoch, 27. Juli 2022 14:16
An: henry.gadacz(a)stud.h-da.de; tpm2(a)lists.01.org
Betreff: [tpm2] Re: tpm2-pytss connect to dockerized swtpm

HI,

swtpm only listens on 127.0.0.1 by default, so unless you have changed that it wont be accessible by any other address.
docker compose seems to use the same network namespace for each container so localhost should work, but it might be as simple as that the python script runs before swtpm is ready.
The unit tests for tpm2-pytss tries to connect to swtpm a couple of times with a small sleep in between each try to get around that, so try adding for example time.sleep(5) before calling ESAPI(...) to see if that helps.

/Erik

On Wed, 2022-07-27 at 10:29 +0200, henry.gadacz(a)stud.h-da.de <mailto:henry.gadacz(a)stud.h-da.de>  wrote:

	Hello everyone,
	 
	I am trying to accomplish the following, but did not succeed and I hope someone can help me.
	I want to have a docker compose with two containers. In the first container I want to run the swtpm (https://github.com/stefanberger/swtpm) and in the other a python script that uses tpm2-pytss to connect to the swtpm in the first container. 
	 
	When I run swtpm and the python script in the same container it works.
	In order to run them in separate containers I just duplicated the Dockerfile (I know this has some overhead, but to make sure don’t miss any dependencies), changed the docker CMD command to either run the python script or the swtpm and renamed them to Dockerfile_app_test and Dockerfile_tpm_test.
	 
	My docker compose file is looking like this:
	version: '3.7'
	services:

	  app:
	    container_name: app
	    build:
	      context: .
	      dockerfile: Dockerfile_app_test
	    restart: unless-stopped

	  tpm:
	    container_name: tpm
	    build:
	      context: .
	      dockerfile: Dockerfile_tpm_test
	    ports:
	      - "2321:2321"
	      - "2322:2322"
	    restart: unless-stopped
	 
	 
	My python script is:
	from tpm2_pytss import *
	if __name__ == '__main__':
	    print("TPM test application")
	    tpm = ESAPI(tcti="swtpm:host=tpm,port=2321")
	    tpm.startup(TPM2_SU.CLEAR)
	    
	    r = tpm.get_random(8)
	    print("type is ", type(r))
	    print("r    is ", str(r))
	    print("as int  ", int(str(r), 16))

	 
	When I run it in one Dockerfile I used 
	tpm = ESAPI(tcti="swtpm:host=localhost,port=2321")

	so I thought changing the host name to the docker container name should do it but I always get the following errors:
	app  | WARNING:tcti:src/util/io.c:262:socket_connect() Failed to connect to host 172.21.0.2, port 2321: errno 111: Connection refused 
	app  | ERROR:tcti:src/tss2-tcti/tcti-swtpm.c:614:Tss2_Tcti_Swtpm_Init() Cannot connect to swtpm TPM socket 
	app  | ERROR:tcti:src/tss2-tcti/tctildr-dl.c:170:tcti_from_file() Could not initialize TCTI file: swtpm 
	app  | ERROR:tcti:src/tss2-tcti/tctildr.c:428:Tss2_TctiLdr_Initialize_Ex() Failed to instantiate TCTI 
	app  | Traceback (most recent call last):
	app  |   File "/app/main.py", line 70, in <module>
	app  |     tpm = ESAPI(tcti="swtpm:host=tpm,port=2321")
	app  |   File "/usr/local/lib/python3.10/dist-packages/tpm2_pytss/ESAPI.py", line 123, in __init__
	app  |     tcti = TCTILdr.parse(tcti)
	app  |   File "/usr/local/lib/python3.10/dist-packages/tpm2_pytss/TCTILdr.py", line 54, in parse
	app  |     return cls(name, conf)
	app  |   File "/usr/local/lib/python3.10/dist-packages/tpm2_pytss/TCTILdr.py", line 29, in __init__
	app  |     _chkrc(lib.Tss2_TctiLdr_Initialize_Ex(name, conf, self._ctx_pp))
	app  |   File "/usr/local/lib/python3.10/dist-packages/tpm2_pytss/internal/utils.py", line 32, in _chkr
	app  |     raise TSS2_Exception(rc)
	app  | tpm2_pytss.TSS2_Exception.TSS2_Exception: tcti:IO failure
	app exited with code 1

	 
	 
	I know it’s not a plain tpm2-tss question, but does anyone has experience with that and can help me? 
	 
	Kind regards, 
	Henry
	 
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