guid.c: add function to calculate owner GUID for known authenticated variables

Signed-off-by: James Bottomley <JBottomley@Parallels.com>

2 files changed, 23 insertions, 0 deletions

diff --git a/include/guid.h b/include/guid.h
index 17aa6af..5ca8b1c 100644
--- a/include/guid.h
+++ b/include/guid.h
@@ -4,6 +4,7 @@
 const char *guid_to_str(EFI_GUID *guid);
 int str_to_guid(const char *str, EFI_GUID *guid);
 int compare_guid(EFI_GUID *g1, EFI_GUID *g2);
+EFI_GUID *get_owner_guid(char *var);
 #endif
 
 extern EFI_GUID GV_GUID;
diff --git a/lib/guid.c b/lib/guid.c
index e6471a5..3f8719c 100644
--- a/lib/guid.c
+++ b/lib/guid.c
@@ -7,6 +7,8 @@
 #include <guid.h>
 #include <stdio.h>
 
+#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
+
 #ifndef BUILD_EFI
 /* EFI has %g for this, so it's only needed in platform c */
 const char *guid_to_str(EFI_GUID *guid)
@@ -40,8 +42,28 @@ compare_guid(EFI_GUID *g1, EFI_GUID *g2)
 {
 	return memcmp(g1, g2, sizeof(*g1));
 }
+
+EFI_GUID *
+get_owner_guid(char *var)
+{
+	char *variables[] = { "PK", "KEK", "db", "dbx", "dbt", "MokList" };
+	EFI_GUID *owners[] = { &GV_GUID, &GV_GUID, &SIG_DB, &SIG_DB, &SIG_DB, &MOK_OWNER };
+	EFI_GUID *owner = NULL;
+	int i;
+
+	for(i = 0; i < ARRAY_SIZE(variables); i++) {
+		if (strcmp(var, variables[i]) == 0) {
+			owner = owners[i];
+			break;
+		}
+	}
+
+	return owner;
+}
 #endif
 
+
+
 /* all the necessary guids */
 EFI_GUID GV_GUID = EFI_GLOBAL_VARIABLE;
 EFI_GUID SIG_DB = { 0xd719b2cb, 0x3d3a, 0x4596, {0xa3, 0xbc, 0xda, 0xd0,  0xe, 0x67, 0x65, 0x6f }};