Fix for "TPM2_ZGen_2Phase: FAIL (expected Z size 32, got outZ1=68 outZ2=68)"

Author: dgarske

examples/native/native_test.c

@@ -1173,18 +1173,22 @@ int TPM2_Native_TestArgs(void* userCtx, int argc, char *argv[])
         if (rc == TPM_RC_SUCCESS) {
             /* For the P-256 curve configured above (TPM_ECC_NIST_P256),
              * each Z output is the x-coordinate of the shared point, so
-             * its size must equal the curve byte length (32). A mutant
+             * its size must equal the curve byte length (32). The outer
+             * TPM2B_ECC_POINT .size field wraps TPMS_ECC_POINT (x + y),
+             * so validate the x-coordinate size specifically. A mutant
              * that returns any non-zero-sized output would otherwise
              * slip past a plain non-empty check. */
             const int expectedZSz = 32; /* P-256 coordinate size */
-            printf("TPM2_ZGen_2Phase: outZ1 %d, outZ2 %d\n",
-                cmdOut.zgen2.outZ1.size, cmdOut.zgen2.outZ2.size);
-            if (cmdOut.zgen2.outZ1.size != expectedZSz ||
-                cmdOut.zgen2.outZ2.size != expectedZSz) {
-                printf("TPM2_ZGen_2Phase: FAIL (expected Z size %d, "
-                    "got outZ1=%d outZ2=%d)\n",
+            printf("TPM2_ZGen_2Phase: outZ1.x %d, outZ2.x %d\n",
+                cmdOut.zgen2.outZ1.point.x.size,
+                cmdOut.zgen2.outZ2.point.x.size);
+            if (cmdOut.zgen2.outZ1.point.x.size != expectedZSz ||
+                cmdOut.zgen2.outZ2.point.x.size != expectedZSz) {
+                printf("TPM2_ZGen_2Phase: FAIL (expected Z x size %d, "
+                    "got outZ1.x=%d outZ2.x=%d)\n",
                     expectedZSz,
-                    cmdOut.zgen2.outZ1.size, cmdOut.zgen2.outZ2.size);
+                    cmdOut.zgen2.outZ1.point.x.size,
+                    cmdOut.zgen2.outZ2.point.x.size);
                 rc = -1;
                 goto exit;
             }