From 1a541fbef647cd495e1c9fb9667d0f0525ff5fd7 Mon Sep 17 00:00:00 2001

From: Javier Martinez Canillas <javierm@redhat.com>

Date: Mon, 30 Jul 2018 11:40:19 +0200

Subject: [PATCH] tpm2_create: Use better object attributes defaults for

 authentication

The tpm2_create tool allows to define a policy session or a password for

authentication. By default no policy session is used and the password is

empty, which means that this empty password is used for authentication.

So the default object attribute flag userWithAuth is set in order to use

the empty password. This isn't a good default though if a policy is set,

since in this case the policy session has to be used for authentication

instead of an empty password.

If a policy is defined, the userWithAuth bit has to be clear unless the

user defines a password so in that case authentication would happen only

using the policy session or the defined password.

Also add these cases in the integration test to detect regressions.

Fixes: #1123

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>

---

 test/system/test_tpm2_unseal.sh | 51 +++++++++++++++++++++++++++++++++

 tools/tpm2_create.c             |  4 +++

 2 files changed, 55 insertions(+)

diff --git a/test/system/test_tpm2_unseal.sh b/test/system/test_tpm2_unseal.sh

index 1015a43..abfffce 100755

--- a/test/system/test_tpm2_unseal.sh

+++ b/test/system/test_tpm2_unseal.sh

@@ -109,4 +109,55 @@ unsealed=`tpm2_unseal -c $file_unseal_key_ctx -L ${alg_pcr_policy}:${pcr_ids} -F

 test "$unsealed" == "$secret"

+# Test that unseal fails if a PCR policy isn't provided

+

+trap - ERR

+

+tpm2_unseal -c $file_unseal_key_ctx 2> /dev/null

+if [ $? != 1 ]; then

+  echo "tpm2_unseal didn't fail without a PCR policy!"

+  exit 1

+fi

+

+# Test that unseal fails if PCR state isn't the same as the defined PCR policy

+

+pcr_extend=$(echo $pcr_ids | cut -d ',' -f1)

+

+tpm2_pcrextend $pcr_extend:sha1=6c10289a8da7f774cf67bd2fc8502cd4b585346a

+

+tpm2_unseal -c $file_unseal_key_ctx -L ${alg_pcr_policy}:${pcr_ids} -F $file_pcr_value 2> /dev/null

+if [ $? != 1 ]; then

+  echo "tpm2_unseal didn't fail with a PCR state different than the policy!"

+  exit 1

+fi

+

+# Test that the object can be unsealed without a policy but a password

+

+trap onerror ERR

+

+rm $file_unseal_key_pub $file_unseal_key_priv $file_unseal_key_name

+

+tpm2_pcrlist -Q -L ${alg_pcr_policy}:${pcr_ids} -o $file_pcr_value

+

+tpm2_createpolicy -Q -P -L ${alg_pcr_policy}:${pcr_ids} -F $file_pcr_value -f $file_policy

+

+tpm2_create -Q -g $alg_create_obj -G $alg_create_key -u $file_unseal_key_pub -r $file_unseal_key_priv -I- -c $file_primary_key_ctx -L $file_policy -K secretpass\

+  -A 'sign|fixedtpm|fixedparent|sensitivedataorigin' <<< $secret

+

+tpm2_load -Q -c $file_primary_key_ctx  -u $file_unseal_key_pub  -r $file_unseal_key_priv -n $file_unseal_key_name -C $file_unseal_key_ctx

+

+unsealed=`tpm2_unseal -c $file_unseal_key_ctx -P secretpass`

+

+test "$unsealed" == "$secret"

+

+# Test that unseal fails when using a wrong password

+

+trap - ERR

+

+tpm2_unseal -c $file_unseal_key_ctx -P wrongpass 2> /dev/null

+if [ $? != 1 ]; then

+  echo "tpm2_unseal didn't fail when using a wrong object password!"

+  exit 1

+fi

+

 exit 0

diff --git a/tools/tpm2_create.c b/tools/tpm2_create.c

index 41d7b42..15166fc 100644

--- a/tools/tpm2_create.c

+++ b/tools/tpm2_create.c

@@ -256,6 +256,7 @@ static bool on_option(char key, char *value) {

             return false;

         }

         ctx.flags.K = 1;

+        ctx.in_public.t.publicArea.objectAttributes.userWithAuth = 1;

         break;

     case 'g':

         ctx.nameAlg = tpm2_alg_util_from_optarg(value);

@@ -294,6 +295,9 @@ static bool on_option(char key, char *value) {

             return false;

         }

         ctx.flags.L = 1;

+        if (!ctx.flags.K) {

+             ctx.in_public.t.publicArea.objectAttributes.userWithAuth = 0;

+        }

         break;

     case 'S':

         if (!tpm2_util_string_to_uint32(value, &ctx.session_data.sessionHandle)) {

-- 

2.17.0