Allow indepdent SkuSi and SBAT revocation updates

While a revocations.efi binary can contain either SBAT revocations,
SkuSi revocations, or both, it is desirable to package them separately
so that higher level tools such as fwupd can decide which ones to put
in place at a given moment. This changes revocations.efi to
revocations_sbat.efi and revocations_sku.efi

Signed-off-by: Jan Setje-Eilers <Jan.SetjeEilers@oracle.com>

include/sbat.h

@@ -38,7 +38,8 @@
 #define POLICY_RESET		3
 #define POLICY_NOTREAD		255
 
-#define REVOCATIONFILE L"revocations.efi"
+#define SBATREVOCATIONFILE L"revocations_sbat.efi"
+#define SKUSIREVOCATIONFILE L"revocations_sku.efi"
 
 extern UINTN _sbat, _esbat;
 

shim.c

@@ -1422,7 +1422,7 @@ check_section_helper(char *section_name, int len, void **pointer,
 	                     section, data, datasize, minsize)
 
 EFI_STATUS
-load_revocations_file(EFI_HANDLE image_handle, CHAR16 *PathName)
+load_revocations_file(EFI_HANDLE image_handle, CHAR16 *FileName, CHAR16 *PathName)
 {
 	EFI_STATUS efi_status = EFI_SUCCESS;
 	PE_COFF_LOADER_IMAGE_CONTEXT context;
@@ -1437,13 +1437,12 @@ load_revocations_file(EFI_HANDLE image_handle, CHAR16 *PathName)
 	uint8_t *ssps_latest = NULL;
 	uint8_t *sspv_latest = NULL;
 
-	efi_status = read_image(image_handle, L"revocations.efi", &PathName,
+	efi_status = read_image(image_handle, FileName, &PathName,
 				&data, &datasize,
 				SUPPRESS_NETBOOT_OPEN_FAILURE_NOISE);
-	if (EFI_ERROR(efi_status))
-		return efi_status;
+	if (!EFI_ERROR(efi_status))
+		efi_status = verify_image(data, datasize, shim_li, &context);
 
-	efi_status = verify_image(data, datasize, shim_li, &context);
 	if (EFI_ERROR(efi_status)) {
 		dprint(L"revocations failed to verify\n");
 		return efi_status;
@@ -1597,7 +1596,8 @@ load_unbundled_trust(EFI_HANDLE image_handle)
 		 * updates unconditionally in those cases. This may produce
 		 * console noise when the file is not present.
 		 */
-		load_revocations_file(image_handle, REVOCATIONFILE, PathName);
+		load_revocations_file(image_handle, SKUSIREVOCATIONFILE, PathName);
+		load_revocations_file(image_handle, SBATREVOCATIONFILE, PathName);
 		goto done;
 	}
 
@@ -1667,17 +1667,17 @@ load_unbundled_trust(EFI_HANDLE image_handle)
 		}
 
 		/*
-		 * In the event that there are unprocessed revocation
+		 * In the event that there are unprocessed sbat revocation
 		 * additions, they could be intended to ban any *new* trust
 		 * anchors we find here. With that in mind, we always want to
 		 * do a pass of loading revocations before we try to add
 		 * anything new to our allowlist. This is done by making two
 		 * passes over the directory, first to search for the
-		 * revocations.efi file then to search for shim_certificate*.efi
+		 * revocations_sbat.efi file then to search for shim_certificate*.efi
 		 */
 		if (search_revocations &&
-		    StrCaseCmp(info->FileName, REVOCATIONFILE) == 0) {
-			load_revocations_file(image_handle, PathName);
+		    StrCaseCmp(info->FileName, SBATREVOCATIONFILE) == 0) {
+			load_revocations_file(image_handle, SBATREVOCATIONFILE, PathName);
 			search_revocations = FALSE;
 			efi_status = root->Open(root, &dir, PathName,
 						EFI_FILE_MODE_READ, 0);
@@ -1688,9 +1688,14 @@ load_unbundled_trust(EFI_HANDLE image_handle)
 			}
 		}
 
-		if (!search_revocations &&
-		    StrnCaseCmp(info->FileName, L"shim_certificate", 16) == 0) {
-			load_cert_file(image_handle, info->FileName, PathName);
+		if (!search_revocations) {
+			if (StrnCaseCmp(info->FileName, L"shim_certificate", 16) == 0) {
+				load_cert_file(image_handle, info->FileName, PathName, 0);
+			}
+			if (StrCaseCmp(info->FileName, SKUSIREVOCATIONFILE) == 0) {
+				load_revocations_file(image_handle,
+					SKUSIREVOCATIONFILE, PathName);
+			}
 		}
 	}
 done: