--- a/compat/verification/pkcs7_trust.c
+++ b/compat/verification/pkcs7_trust.c
@@ -116,7 +116,7 @@ static int pkcs7_validate_trust_one(stru
 	return -ENOKEY;
 
 matched:
-	ret = verify_signature(key, sig);
+	ret = public_key_verify_signature(key->public_key, sig);
 	key_put(key);
 	if (ret < 0) {
 		if (ret == -ENOMEM)
--- a/compat/verification/x509_public_key.c
+++ b/compat/verification/x509_public_key.c
@@ -13,11 +13,8 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
-#include <keys/asymmetric-subtype.h>
-#include <keys/asymmetric-parser.h>
 #include <keys/system_keyring.h>
 #include <crypto/hash.h>
-#include "asymmetric_keys.h"
 #include "x509_parser.h"
 
 /*
@@ -155,6 +152,7 @@ not_self_signed:
 	return 0;
 }
 
+#if 0
 /*
  * Attempt to parse a data blob for a key as an X509 certificate.
  */
@@ -273,3 +271,4 @@ module_exit(x509_key_exit);
 MODULE_DESCRIPTION("X.509 certificate parser");
 MODULE_AUTHOR("Red Hat, Inc.");
 MODULE_LICENSE("GPL");
+#endif
--- a/include/crypto/pkcs7.h
+++ b/include/crypto/pkcs7.h
@@ -2,5 +2,10 @@
 #ifndef CPTCFG_BPAUTO_PKCS7
 #include_next <crypto/pkcs7.h>
 #else
+#define pkcs7_verify LINUX_BACKPORT(pkcs7_verify)
+#define pkcs7_get_content_data LINUX_BACKPORT(pkcs7_get_content_data)
+#define pkcs7_parse_message LINUX_BACKPORT(pkcs7_parse_message)
+#define pkcs7_free_message LINUX_BACKPORT(pkcs7_free_message)
+#define pkcs7_validate_trust LINUX_BACKPORT(pkcs7_validate_trust)
 #include <crypto/backport-pkcs7.h>
 #endif /* CPTCFG_BPAUTO_PKCS7 */
--- a/compat/verification/x509_parser.h
+++ b/compat/verification/x509_parser.h
@@ -13,6 +13,10 @@
 #include <crypto/public_key.h>
 #include <keys/asymmetric-type.h>
 
+#define x509_decode_time LINUX_BACKPORT(x509_decode_time)
+#define x509_cert_parse LINUX_BACKPORT(x509_cert_parse)
+#define x509_free_certificate LINUX_BACKPORT(x509_free_certificate)
+
 struct x509_certificate {
 	struct x509_certificate *next;
 	struct x509_certificate *signer;	/* Certificate that signed this one */
--- a/include/crypto/backport-public_key.h
+++ b/include/crypto/backport-public_key.h
@@ -46,27 +46,6 @@ extern void public_key_signature_free(st
 
 extern struct asymmetric_key_subtype public_key_subtype;
 
-struct key;
-struct key_type;
-union key_payload;
-
-extern int restrict_link_by_signature(struct key *dest_keyring,
-				      const struct key_type *type,
-				      const union key_payload *payload,
-				      struct key *trust_keyring);
-
-extern int restrict_link_by_key_or_keyring(struct key *dest_keyring,
-					   const struct key_type *type,
-					   const union key_payload *payload,
-					   struct key *trusted);
-
-extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring,
-						 const struct key_type *type,
-						 const union key_payload *payload,
-						 struct key *trusted);
-
-extern int verify_signature(const struct key *key,
-			    const struct public_key_signature *sig);
 
 int public_key_verify_signature(const struct public_key *pkey,
 				const struct public_key_signature *sig);