Add TPM version checking

firmware/lib/rollback_index.c

 /* Copyright (c) 2010-2011 The Chromium OS Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  *
  * Functions for querying, manipulating and locking rollback indices
  * stored in the TPM NVRAM.
  */
 
 #include "rollback_index.h"
 
@@ skipping 283 matching lines @@
   /* Initializes the TPM, but ignores return codes.  In ChromeOS
    * environment, doesn't even talk to the TPM. */
   TlclLibInit();
   TlclStartup();
   TlclContinueSelfTest();
 #endif
   *version = 0;
   return TPM_SUCCESS;
 }
 
+uint32_t RollbackFirmwareRead(uint32_t* version) {
+  *version = 0;
+  return TPM_SUCCESS;
+}
+
 uint32_t RollbackFirmwareWrite(uint32_t version) {
   return TPM_SUCCESS;
 }
 
 uint32_t RollbackFirmwareLock(void) {
   return TPM_SUCCESS;
 }
 
 uint32_t RollbackKernelRecovery(int developer_mode) {
 #ifndef CHROMEOS_ENVIRONMENT
@@ skipping 36 matching lines @@
 
 uint32_t RollbackFirmwareSetup(int developer_mode, uint32_t* version) {
   RollbackSpaceFirmware rsf;
 
   RETURN_ON_FAILURE(SetupTPM(0, developer_mode, &rsf));
   *version = rsf.fw_versions;
   VBDEBUG(("TPM: RollbackFirmwareSetup %x\n", (int)rsf.fw_versions));
   return TPM_SUCCESS;
 }
 
+uint32_t RollbackFirmwareRead(uint32_t* version) {
+  RollbackSpaceFirmware rsf;
+
+  RETURN_ON_FAILURE(ReadSpaceFirmware(&rsf));
+  VBDEBUG(("TPM: RollbackFirmwareRead %x --> %x\n", (int)rsf.fw_versions,
+           (int)version));
+  *version = rsf.fw_versions;
+  VBDEBUG(("TPM: RollbackFirmwareRead %x\n", (int)rsf.fw_versions));
+  return TPM_SUCCESS;
+}
 
 uint32_t RollbackFirmwareWrite(uint32_t version) {
   RollbackSpaceFirmware rsf;
 
   RETURN_ON_FAILURE(ReadSpaceFirmware(&rsf));
   VBDEBUG(("TPM: RollbackFirmwareWrite %x --> %x\n", (int)rsf.fw_versions,
            (int)version));
   rsf.fw_versions = version;
   return WriteSpaceFirmware(&rsf);
 }
@@ skipping 13 matching lines @@
    * Physical Presence on in either case. */
   rvs = SetupTPM(1, developer_mode, &rsf);
   rve = SetTPMBootModeState(developer_mode,
                             1,  /* Recovery Mode Status. */
                             0);  /* In recovery mode, there is no RW firmware
                                   * keyblock flag. */
   return (TPM_SUCCESS == rvs) ? rve : rvs;
 }
 
 uint32_t RollbackKernelRead(uint32_t* version) {
-  if (g_rollback_recovery_mode) {
-    *version = 0;
-  } else {
-    RollbackSpaceKernel rsk;
-    uint32_t perms;
+  RollbackSpaceKernel rsk;
+  uint32_t perms;
 
-    /* Read the kernel space and verify its permissions.  If the kernel
-     * space has the wrong permission, or it doesn't contain the right
-     * identifier, we give up.  This will need to be fixed by the
-     * recovery kernel.  We have to worry about this because at any time
-     * (even with PP turned off) the TPM owner can remove and redefine a
-     * PP-protected space (but not write to it). */
-    RETURN_ON_FAILURE(ReadSpaceKernel(&rsk));
-    RETURN_ON_FAILURE(TlclGetPermissions(KERNEL_NV_INDEX, &perms));
-    if (TPM_NV_PER_PPWRITE != perms || ROLLBACK_SPACE_KERNEL_UID != rsk.uid)
-      return TPM_E_CORRUPTED_STATE;
+  /* Read the kernel space and verify its permissions.  If the kernel
+   * space has the wrong permission, or it doesn't contain the right
+   * identifier, we give up.  This will need to be fixed by the
+   * recovery kernel.  We have to worry about this because at any time
+   * (even with PP turned off) the TPM owner can remove and redefine a
+   * PP-protected space (but not write to it). */
+  RETURN_ON_FAILURE(ReadSpaceKernel(&rsk));
+  RETURN_ON_FAILURE(TlclGetPermissions(KERNEL_NV_INDEX, &perms));
+  if (TPM_NV_PER_PPWRITE != perms || ROLLBACK_SPACE_KERNEL_UID != rsk.uid)
+    return TPM_E_CORRUPTED_STATE;
 
-    *version = rsk.kernel_versions;
-    VBDEBUG(("TPM: RollbackKernelRead %x\n", (int)rsk.kernel_versions));
-  }
+  *version = rsk.kernel_versions;
+  VBDEBUG(("TPM: RollbackKernelRead %x\n", (int)rsk.kernel_versions));
   return TPM_SUCCESS;
 }
 
 uint32_t RollbackKernelWrite(uint32_t version) {
-  if (g_rollback_recovery_mode) {
-    return TPM_SUCCESS;
-  } else {
-    RollbackSpaceKernel rsk;
-    RETURN_ON_FAILURE(ReadSpaceKernel(&rsk));
-    VBDEBUG(("TPM: RollbackKernelWrite %x --> %x\n", (int)rsk.kernel_versions,
-             (int)version));
-    rsk.kernel_versions = version;
-    return WriteSpaceKernel(&rsk);
-  }
+  RollbackSpaceKernel rsk;
+  RETURN_ON_FAILURE(ReadSpaceKernel(&rsk));
+  VBDEBUG(("TPM: RollbackKernelWrite %x --> %x\n", (int)rsk.kernel_versions,
+           (int)version));
+  rsk.kernel_versions = version;
+  return WriteSpaceKernel(&rsk);
 }
 
 uint32_t RollbackKernelLock(void) {
   if (g_rollback_recovery_mode) {
     return TPM_SUCCESS;
   } else {
     return TlclLockPhysicalPresence();
   }
 }
 
 #endif // DISABLE_ROLLBACK_TPM