Run the API tests in the TPM CI job

- No job compiled a wolfSSH test binary with WOLFSSH_TPM defined, so a
  test guarded on it compiled out everywhere and could not gate a
  merge. This job enables TPM but only builds; the jobs that run make
  check do not enable it.
- Add a make check step. automake's check-am builds every check_PROGRAM
  regardless of the TESTS override, so this is the only job that
  compiles wolfSSH's tests with TPM support.
- Override TESTS to run only tests/api.test, the one suite with
  TPM-specific tests. kex.test also aborts in the example client, which
  demands -K in a TPM build.
- Restrict it to one matrix cell. The 2x2x2 matrix varies the simulator
  and the host key, neither of which these tests touch.
- Assert -DWOLFSSH_TPM in AM_CPPFLAGS first. A build without it
  compiles the guarded tests out and still exits 0, a hollow pass.
- Dump tests/api.log on failure and archive it.

Author: yosuke-wolfssl

.github/workflows/tpm-ssh.yml

@@ -115,6 +115,25 @@ jobs:
         sudo make install
         sudo ldconfig
 
+    # Builds every check_PROGRAM -- no other job compiles wolfSSH's tests
+    # with TPM support -- but runs only api.test, the one suite with TPM
+    # tests. One cell: these tests ignore the simulator and host key.
+    - name: Run API tests
+      if: matrix.keytype == 'ecc' && matrix.sim == 'ibmswtpm2' && matrix.hostkey == 'raw'
+      run: |
+        cd wolfssh
+        # A non-TPM build compiles every TPM-guarded test out, silently.
+        if ! grep -q '^AM_CPPFLAGS = .*-DWOLFSSH_TPM' Makefile; then
+            echo "Not a TPM build; the TPM-guarded tests would compile out."
+            grep '^AM_CPPFLAGS' Makefile
+            exit 1
+        fi
+        make check TESTS=tests/api.test
+
+    - name: Show API test log on failure
+      if: failure() && (matrix.keytype == 'ecc' && matrix.sim == 'ibmswtpm2' && matrix.hostkey == 'raw')
+      run: cat wolfssh/tests/api.log || true
+
     # Server host key resident in the TPM: the private key never enters RAM.
     - name: Test TPM host key (${{ matrix.keytype }})
       if: matrix.hostkey == 'raw'
@@ -222,3 +241,4 @@ jobs:
           wolfssh/tpmcert_client.txt
           wolfssh/tpmcert_server_neg.txt
           wolfssh/tpmcert_client_neg.txt
+          wolfssh/tests/api.log