cr50: test: extended command code does not have to be passed as argument

The extended command code is fixed, there is no need to pass it as a
parameter when calling functions wrapping and unwrapping extended
commands.

BRANCH=none
BUG=chrome-os-partner:43025
TEST=AES tests still pass:
  $ ./test/tpm_test/tpmtest.py
  Starting MPSSE at 800 kHz
  Connected to device vid:did:rid of 1ae0:0028:00
  SUCCESS: AES:ECB common
  SUCCESS: AES:ECB128 1
  SUCCESS: AES:ECB192 1
  SUCCESS: AES:ECB256 1
  SUCCESS: AES:ECB256 2
  SUCCESS: AES:CTR128I 1
  -New max timeout: 1 s
  SUCCESS: AES:CTR256I 1

Change-Id: Ic0c9d7983755de8380b57e841891fd638ef2c62a
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/314690
Reviewed-by: Nagendra Modadugu <ngm@google.com>

1 files changed, 6 insertions, 10 deletions

diff --git a/test/tpm_test/tpmtest.py b/test/tpm_test/tpmtest.py
index c2056c01c7..5117f2b1ad 100755
--- a/test/tpm_test/tpmtest.py
+++ b/test/tpm_test/tpmtest.py
@@ -95,12 +95,12 @@ class TPM(object):
     self.validate(response, response_mode=True)
     return response
 
-  def wrap_ext_command(self, cmd_code, subcmd_code, cmd_body):
+  def wrap_ext_command(self, subcmd_code, cmd_body):
     return struct.pack(self.HEADER_FMT, 0x8001,
                        len(cmd_body) + struct.calcsize(self.HEADER_FMT),
-                       cmd_code, subcmd_code) + cmd_body
+                       EXT_CMD, subcmd_code) + cmd_body
 
-  def unwrap_ext_response(self, expected_cmd, expected_subcmd, response):
+  def unwrap_ext_response(self, expected_subcmd, response):
     """Verify basic validity and strip off TPM extended command header.
 
     Get the response generated by the device, as it came off the wire, verify
@@ -108,8 +108,6 @@ class TPM(object):
     command header and return the payload to the caller.
 
     Args:
-      expected_cmd: an int, up to 32 bits, expected value in the
-        command/response field of the header. expected_subcmd, response
       expected_subcmd: an int, up to 16 bits in size, the extension command
         this response is supposed to be for.
       response: a binary string, the actual response received over the wire.
@@ -124,7 +122,7 @@ class TPM(object):
                                            response[:header_size])
     if tag != 0x8001:
       raise TpmError('Wrong response tag: %4.4x' % tag)
-    if cmd != expected_cmd:
+    if cmd != EXT_CMD:
       raise TpmError('Unexpected response command field: %8.8x' % cmd)
     if subcmd != expected_subcmd:
       raise TpmError('Unexpected response subcommand field: %2.2x' %
@@ -288,10 +286,8 @@ def crypto_run(node_name, op_type, key, iv, in_text, out_text, tpm, debug_mode):
   cmd += in_text
   if debug_mode:
     print('%d:%d cmd size' % (op_type, mode.subcmd), len(cmd), hex_dump(cmd))
-  wrapped_response = tpm.command(tpm.wrap_ext_command(
-      EXT_CMD, mode.subcmd, cmd))
-  real_out_text = tpm.unwrap_ext_response(
-      EXT_CMD, mode.subcmd, wrapped_response)
+  wrapped_response = tpm.command(tpm.wrap_ext_command(mode.subcmd, cmd))
+  real_out_text = tpm.unwrap_ext_response(mode.subcmd, wrapped_response)
   if out_text:
     if len(real_out_text) > len(out_text):
       real_out_text = real_out_text[:len(out_text)]  # Ignore padding