Taken changes from commit aaa09b35e73c4a35fc119d225e5241199d7cf5aa,
tweaked to fit into our older codebase
diff --git a/MokManager.c b/MokManager.c
index 01697bd..aaf6cb1 100644
--- a/MokManager.c	2020-03-24 17:13:03.250000678 +0000
+++ b/MokManager.c	2020-03-24 17:15:08.586705154 +0000
@@ -1077,7 +1077,7 @@
 			continue;
 
 		DataSize += sizeof(EFI_SIGNATURE_LIST);
-		if (CompareGuid(&(list[i].Type), &X509_GUID) == 0)
+		if (CompareMem(&(list[i].Type), &X509_GUID, sizeof(EFI_GUID)) == 0)
 			DataSize += sizeof(EFI_GUID);
 		DataSize += list[i].MokSize;
 	}
@@ -1099,7 +1099,7 @@
 		CertList->SignatureType = list[i].Type;
 		CertList->SignatureHeaderSize = 0;
 
-		if (CompareGuid(&(list[i].Type), &X509_GUID) == 0) {
+		if (CompareMem(&(list[i].Type), &X509_GUID, sizeof(EFI_GUID)) == 0) {
 			CertList->SignatureListSize = list[i].MokSize +
 			    sizeof(EFI_SIGNATURE_LIST) + sizeof(EFI_GUID);
 			CertList->SignatureSize =
@@ -1140,7 +1140,7 @@
 	int i;
 
 	for (i = 0; i < mok_num; i++) {
-		if (CompareGuid(&(mok[i].Type), &X509_GUID) != 0)
+		if (CompareMem(&(mok[i].Type), &X509_GUID, sizeof(EFI_GUID)) != 0)
 			continue;
 
 		if (mok[i].MokSize == key_size &&
@@ -1191,7 +1191,7 @@
 	sig_size = hash_size + sizeof(EFI_GUID);
 
 	for (i = 0; i < mok_num; i++) {
-		if ((CompareGuid(&(mok[i].Type), &Type) != 0) ||
+		if ((CompareMem(&(mok[i].Type), &Type, sizeof(EFI_GUID)) != 0) ||
 		    (mok[i].MokSize < sig_size))
 			continue;
 
@@ -1355,7 +1355,7 @@
 
 	/* Search and destroy */
 	for (i = 0; i < del_num; i++) {
-		if (CompareGuid(&(del_key[i].Type), &X509_GUID) == 0) {
+		if (CompareMem(&(del_key[i].Type), &X509_GUID, sizeof(EFI_GUID)) == 0) {
 			delete_cert(del_key[i].Mok, del_key[i].MokSize,
 				    mok, mok_num);
 		} else if (is_sha2_hash(del_key[i].Type)) {