How to get the access to the raw TPM command

[stefanodevenuto]

I'm trying to dump out the raw TPM command created using different SAPI calls, but I can't find any API for the purpose. Moreover, the cmdBuffer inside TSS2_SYS_CONTEXT can't be accessed, since this last one is an opaque type.

Therefore, is there currently a way to do it?
Thanks!

[JuergenReppSIT]

In the SAPI there is one command to access the command buffer: Tss2_Sys_GetCpBuffer which returns a pointer to the marshaled command parameters. But this command can only be called between the calls of the SAPI prepare function [cmd]_Prepare and Tss2_Sys_Execute.
TSS provides two machanisms to dump the command buffer:

• Create a log to stderr if the environment variable TSS2_LOG ist set.
  e.g.: with TSS2_LOG=tcti+trace the commands and responses will be traced.
• For tss >= 3.1.0: create a pcap file e.g. with tcti: pcap:device:/dev/tpmrm0
  The file tpm2_log.pcap will be created. The TPM commands stored in this file can be inspected with wireshark or with the tpmstream tool from https://github.com/joholl/tpmstream. The file name of the pcap file can be canged by setting the environment variable ENV_PCAP_FILE.

[stefanodevenuto]

Thank you so much for the response, Tss2_Sys_GetCpBuffer is exactly what I needed!