feat(drtm): validate launch features in DRTM parameters
Perform sanity checks on the launch features received via DRTM parameters.
Return INVALID_PARAMETERS if they are incorrect.
Change-Id: I7e8068154028d1c8f6b6b45449616bb5711ea76e
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/services/std_svc/drtm/drtm_main.c b/services/std_svc/drtm/drtm_main.c
index 117934f..c302863 100644
--- a/services/std_svc/drtm/drtm_main.c
+++ b/services/std_svc/drtm/drtm_main.c
@@ -34,6 +34,8 @@
/* DRTM-formatted memory map. */
static drtm_memory_region_descriptor_table_t *plat_drtm_mem_map;
+static const plat_drtm_dma_prot_features_t *plat_dma_prot_feat;
+static const plat_drtm_tpm_features_t *plat_tpm_feat;
/* DLME header */
struct_dlme_data_header dlme_data_hdr_init;
@@ -44,8 +46,6 @@
int drtm_setup(void)
{
bool rc;
- const plat_drtm_tpm_features_t *plat_tpm_feat;
- const plat_drtm_dma_prot_features_t *plat_dma_prot_feat;
INFO("DRTM service setup\n");
@@ -322,6 +322,43 @@
return SUCCESS;
}
+/* Function to check if the value is valid for each bit field */
+static int drtm_dl_check_features_sanity(uint32_t val)
+{
+ /**
+ * Ensure that if DLME Authorities Schema (Bits [2:1]) is set, then
+ * DLME image authentication (Bit[6]) must also be set
+ */
+ if ((EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_PCR_USAGE_SCHEMA_MASK,
+ DRTM_LAUNCH_FEAT_PCR_USAGE_SCHEMA_SHIFT) == DLME_AUTH_SCHEMA) &&
+ (EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_DLME_IMG_AUTH_MASK,
+ DRTM_LAUNCH_FEAT_DLME_IMG_AUTH_SHIFT) != DLME_IMG_AUTH)) {
+ return INVALID_PARAMETERS;
+ }
+
+ /**
+ * Check if Bits [5:3] (Memory protection type) matches with platform's
+ * memory protection type
+ */
+ if (EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_MEM_PROTECTION_TYPE_MASK,
+ DRTM_LAUNCH_FEAT_MEM_PROTECTION_TYPE_SHIFT) !=
+ __builtin_ctz(plat_dma_prot_feat->dma_protection_support)) {
+ return INVALID_PARAMETERS;
+ }
+
+ /**
+ * Check if Bits [0] (Type of hashing) matches with platform's
+ * supported hash type.
+ */
+ if (EXTRACT_FIELD(val, DRTM_LAUNCH_FEAT_HASHING_TYPE_MASK,
+ DRTM_LAUNCH_FEAT_HASHING_TYPE_SHIFT) !=
+ plat_tpm_feat->tpm_based_hash_support) {
+ return INVALID_PARAMETERS;
+ }
+
+ return 0;
+}
+
/*
* Note: accesses to the dynamic launch args, and to the DLME data are
* little-endian as required, thanks to TF-A BL31 init requirements.
@@ -369,7 +406,7 @@
args_buf = *a;
rc = mmap_remove_dynamic_region(va_mapping, va_mapping_size);
- if (rc) {
+ if (rc != 0) {
ERROR("%s(): mmap_remove_dynamic_region() failed unexpectedly"
" rc=%d\n", __func__, rc);
panic();
@@ -383,6 +420,13 @@
return NOT_SUPPORTED;
}
+ rc = drtm_dl_check_features_sanity(a->features);
+ if (rc != 0) {
+ ERROR("%s(): drtm_dl_check_features_sanity() failed.\n"
+ " rc=%d\n", __func__, rc);
+ return rc;
+ }
+
if (!(a->dlme_img_off < a->dlme_size &&
a->dlme_data_off < a->dlme_size)) {
ERROR("DRTM: argument offset is outside of the DLME region\n");