[PATCH 4/9] vtpmmgr: Allow specifying srk_handle for TPM2

[Jason Andryuk <jandryuk@gmail.com>]

Bypass taking ownership of the TPM2 if an srk_handle is specified.

This srk_handle must be usable with Null auth for the time being.

Signed-off-by: Jason Andryuk <jandryuk@gmail.com>
---
 docs/man/xen-vtpmmgr.7.pod |  7 +++++++
 stubdom/vtpmmgr/init.c     | 11 ++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/docs/man/xen-vtpmmgr.7.pod b/docs/man/xen-vtpmmgr.7.pod
index 875dcce508..3286954568 100644
--- a/docs/man/xen-vtpmmgr.7.pod
+++ b/docs/man/xen-vtpmmgr.7.pod
@@ -92,6 +92,13 @@ Valid arguments:
 
 =over 4
 
+=item srk_handle=<HANDLE>
+
+Specify a srk_handle for TPM 2.0.  TPM 2.0 uses a key hierarchy, and
+this allow specifying the parent handle for vtpmmgr to create its own
+key under.  Using this option bypasses vtpmmgr trying to take ownership
+of the TPM.
+
 =item owner_auth=<AUTHSPEC>
 
 =item srk_auth=<AUTHSPEC>
diff --git a/stubdom/vtpmmgr/init.c b/stubdom/vtpmmgr/init.c
index 1506735051..c01d03e9f4 100644
--- a/stubdom/vtpmmgr/init.c
+++ b/stubdom/vtpmmgr/init.c
@@ -302,6 +302,11 @@ int parse_cmdline_opts(int argc, char** argv, struct Opts* opts)
             goto err_invalid;
          }
       }
+      else if(!strncmp(argv[i], "srk_handle:", 11)) {
+         if(sscanf(argv[i] + 11, "%x", &vtpm_globals.srk_handle) != 1) {
+            goto err_invalid;
+         }
+      }
       else if(!strncmp(argv[i], "tpmdriver=", 10)) {
          if(!strcmp(argv[i] + 10, "tpm_tis")) {
             opts->tpmdriver = TPMDRV_TPM_TIS;
@@ -586,7 +591,11 @@ TPM_RESULT vtpmmgr2_create(void)
 {
     TPM_RESULT status = TPM_SUCCESS;
 
-    TPMTRYRETURN(tpm2_take_ownership());
+    if ( vtpm_globals.srk_handle == 0 ) {
+        TPMTRYRETURN(tpm2_take_ownership());
+    } else {
+        tpm2_AuthArea_ctor(NULL, 0, &vtpm_globals.srk_auth_area);
+    }
 
    /* create SK */
     TPM2_Create_Params_out out;
-- 
2.30.2