From 1ec07af70925ece698b733d55dedd1d9878b70f2 Mon Sep 17 00:00:00 2001

From: Tadeusz Struk <tadeusz.struk@intel.com>

Date: Fri, 24 Jan 2020 19:05:34 -0800

Subject: [PATCH] esys: zero out ctx->salt after on startAuthSession_finish

The ctx->salt is used to calculate session key during

startAuthSession call if the caller pass a valid tpmKey

parameter. There salt is calculated in the _Async call

and the the session key is calculated in the _Finish call.

The problem is that if in the same context an unsalted

session is created after a salted session the ctx->salt

will still hold the old value and it will incorrectly

be used for session key calculation in the the subsequent

_Finish call. To fix this the salt needs to be set to

cleaned after no longer needed.

Fixes: #1574

Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>

---

 src/tss2-esys/api/Esys_StartAuthSession.c | 1 +

 1 file changed, 1 insertion(+)

diff --git a/src/tss2-esys/api/Esys_StartAuthSession.c b/src/tss2-esys/api/Esys_StartAuthSession.c

index 1717928a717d..6367419d7c9a 100644

--- a/src/tss2-esys/api/Esys_StartAuthSession.c

+++ b/src/tss2-esys/api/Esys_StartAuthSession.c

@@ -497,6 +497,7 @@ Esys_StartAuthSession_Finish(

     goto_if_error(r, "Marshal session name", error_cleanup);

     sessionHandleNode->rsrc.name.size = offset;

+    memset(&esysContext->salt, '\0', sizeof(esysContext->salt));

     esysContext->state = _ESYS_STATE_INIT;

     return TSS2_RC_SUCCESS;

-- 

2.27.0