C_Login: fix segfault when user pin not setup

A command like:
pkcs11-tool --module /usr/lib/libtpm2_pkcs11.so --init-token --label tpmhsm --so-pin foo --pin bar

Will cause a C_Login event becuase --pin is specified. However, C_InitPIN
has not been called to initialize the userpin. This causes an NPD when
trying to load the user sealobjects public and private blobs.

Fixes: tpm2-software#563

Signed-off-by: William Roberts <william.c.roberts@intel.com>

src/lib/session_ctx.c

@@ -266,6 +266,15 @@ CK_RV session_ctx_login(session_ctx *ctx, CK_USER_TYPE user, CK_BYTE_PTR pin, CK
         return CKR_OK;
     }
 
+    sealobject *sealobj = &tok->sealobject;
+    twist sealpub = is_user(user) ? sealobj->userpub : sealobj->sopub;
+    twist sealpriv = is_user(user) ? sealobj->userpriv : sealobj->sopriv;
+
+    /* Detect if PIN has not been set and thus missing the respective user seal object */
+    if (!sealpub) {
+        LOGE("User pin is not initialized, call C_InitPIN");
+        return CKR_USER_PIN_NOT_INITIALIZED;
+    }
 
     CK_RV tmp = tpm_session_start(tok->tctx, tok->pobject.objauth, tok->pobject.handle);
     if (tmp != CKR_OK) {
@@ -275,10 +284,6 @@ CK_RV session_ctx_login(session_ctx *ctx, CK_USER_TYPE user, CK_BYTE_PTR pin, CK
     on_error_flush_session = true;
 
     /* load seal object */
-    sealobject *sealobj = &tok->sealobject;
-    twist sealpub = is_user(user) ? sealobj->userpub : sealobj->sopub;
-    twist sealpriv = is_user(user) ? sealobj->userpriv : sealobj->sopriv;
-
     uint32_t pobj_handle = tok->pobject.handle;
     twist pobjauth = tok->pobject.objauth;
 

test/integration/pkcs11-tool-init.sh.nosetup

@@ -82,4 +82,16 @@ fi
 pkcs11_tool --slot-index=0 --login --pin=mynewuserpin --read-object --type data --label dataobj1 -o objdata2
 cmp objdata objdata2
 
+#
+# Negative test, ensure that this fails
+#
+trap - ERR
+
+# Reproduce https://github.com/tpm2-software/tpm2-pkcs11/issues/563
+pkcs11_tool --slot-index=1 --init-token --label tpmhsm --so-pin foo --pin bar
+if [ $? -eq 0 ]; then
+  echo "Expected login to fail without user pin set"
+  exit 1
+fi
+
 exit 0