From d35dee23b68366af90502c04da4f3eb29d5fe92a Mon Sep 17 00:00:00 2001 From: dp-arm Date: Mon, 12 Dec 2016 14:48:13 +0000 Subject: tbbr: Fix updating of Non-Trusted NV counter The previous code required that a certificate be signed with the ROT key before the platform's NV counter could be updated with the value in the certificate. This implies that the Non-Trusted NV counter was not being updated for Non-Trusted content certificates, as they cannot be signed with the ROT key in the TBBR CoT scheme. The code is reworked to only allow updating the platform's Trusted NV counter when a certificate protected by the Trusted NV counter is signed with the ROT key. Content certificates protected by the Non-Trusted NV counter are allowed to update the platform's Non-Trusted NV counter, assuming that the certificate value is higher than the platform's value. A new optional platform API has been introduced, named plat_set_nv_ctr2(). Platforms may choose to implement it and perform additional checks based on the authentication image descriptor before modifying the NV counters. A default weak implementation is available that just calls into plat_set_nv_ctr(). Fixes ARM-software/tf-issues#426 Change-Id: I4fc978fd28a3007bc0cef972ff1f69ad0413b79c Signed-off-by: dp-arm --- include/plat/common/platform.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/plat') diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h index 5b4d11df..f904292b 100644 --- a/include/plat/common/platform.h +++ b/include/plat/common/platform.h @@ -39,6 +39,7 @@ /******************************************************************************* * Forward declarations ******************************************************************************/ +struct auth_img_desc_s; struct meminfo; struct image_info; struct entry_point_info; @@ -274,6 +275,8 @@ int plat_get_rotpk_info(void *cookie, void **key_ptr, unsigned int *key_len, unsigned int *flags); int plat_get_nv_ctr(void *cookie, unsigned int *nv_ctr); int plat_set_nv_ctr(void *cookie, unsigned int nv_ctr); +int plat_set_nv_ctr2(void *cookie, const struct auth_img_desc_s *img_desc, + unsigned int nv_ctr); #if LOAD_IMAGE_V2 /******************************************************************************* -- cgit v1.2.3