From 0892d0fbbf5778d40d9cd1c81ba841d86e19c5c4 Mon Sep 17 00:00:00 2001
From: Darryl Green <darryl.green@arm.com>
Date: Tue, 20 Aug 2019 09:50:14 +0100
Subject: [PATCH] Initialize key bits to max size + 1 in psa_import_key

In psa_import_key, the key bits value was uninitialized before
calling the secure element driver import function. There is a
potential issue if the driver returns PSA_SUCCESS without setting
the key bits. This shouldn't happen, but shouldn't be discounted
either, so we initialize the key bits to an invalid issue.
---
 library/psa_crypto.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 6ec2a1c383..93af0d398c 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -1835,7 +1835,9 @@ psa_status_t psa_import_key( const psa_key_attributes_t *attributes,
     if( driver != NULL )
     {
         const psa_drv_se_t *drv = psa_get_se_driver_methods( driver );
-        size_t bits;
+        /* The driver should set the number of key bits, however in
+         * case it doesn't, we initialize bits to an invalid value. */
+        size_t bits = PSA_MAX_KEY_BITS + 1;
         if( drv->key_management == NULL ||
             drv->key_management->p_import == NULL )
         {