[PATCH v2] certs: Add EFI_CERT_X509_GUID support for dbx entries

@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/seq_file.h>
 #include <keys/system_keyring.h>
+#include <crypto/pkcs7.h>
 #include "blacklist.h"
 
 static struct key *blacklist_keyring;

@@ -100,6 +101,41 @@ int mark_hash_blacklisted(const char *hash)
 	return 0;
 }
 
+int mark_key_revocationlisted(const char *data, size_t size)
+{
+	key_ref_t key;
+
+	key = key_create_or_update(make_key_ref(blacklist_keyring, true),
+				   "asymmetric",
+				   NULL,
+				   data,
+				   size,
+				   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				    KEY_USR_VIEW),
+				   KEY_ALLOC_NOT_IN_QUOTA |
+				   KEY_ALLOC_BUILT_IN);
+
+	if (IS_ERR(key)) {
+		pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	return 0;
+}
+
+int is_key_revocationlisted(struct pkcs7_message *pkcs7)
+{
+	int ret;
+
+	ret = pkcs7_validate_trust(pkcs7, blacklist_keyring);
+
+	if (ret == 0)
+		return -EKEYREJECTED;
+
+	return -ENOKEY;
+}
+EXPORT_SYMBOL_GPL(is_key_revocationlisted);
+
 /**
  * is_hash_blacklisted - Determine if a hash is blacklisted
  * @hash: The hash to be checked as a binary blob

@@ -241,6 +241,12 @@ int verify_pkcs7_message_sig(const void *data, size_t len,
 			pr_devel("PKCS#7 platform keyring is not available\n");
 			goto error;
 		}
+
+		ret = is_key_revocationlisted(pkcs7);
+		if (ret != -ENOKEY) {
+			pr_devel("PKCS#7 platform key revocationlisted\n");
+			goto error;
+		}
 	}
 	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
 	if (ret < 0) {

@@ -26,11 +26,19 @@ extern int pkcs7_get_content_data(const struct pkcs7_message *pkcs7,
 				  const void **_data, size_t *_datalen,
 				  size_t *_headerlen);
 
+#ifdef CONFIG_PKCS7_MESSAGE_PARSER
 /*
  * pkcs7_trust.c
  */
 extern int pkcs7_validate_trust(struct pkcs7_message *pkcs7,
 				struct key *trust_keyring);
+#else
+static inline int pkcs7_validate_trust(struct pkcs7_message *pkcs7,
+				       struct key *trust_keyring)
+{
+	return -ENOKEY;
+}
+#endif
 
 /*
  * pkcs7_verify.c

@@ -31,11 +31,14 @@ extern int restrict_link_by_builtin_and_secondary_trusted(
 #define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted
 #endif
 
+extern struct pkcs7_message *pkcs7;
 #ifdef CONFIG_SYSTEM_BLACKLIST_KEYRING
 extern int mark_hash_blacklisted(const char *hash);
+extern int mark_key_revocationlisted(const char *data, size_t size);
 extern int is_hash_blacklisted(const u8 *hash, size_t hash_len,
 			       const char *type);
 extern int is_binary_blacklisted(const u8 *hash, size_t hash_len);
+extern int is_key_revocationlisted(struct pkcs7_message *pkcs7);
 #else
 static inline int is_hash_blacklisted(const u8 *hash, size_t hash_len,
 				      const char *type)

@@ -47,6 +50,14 @@ static inline int is_binary_blacklisted(const u8 *hash, size_t hash_len)
 {
 	return 0;
 }
+static inline int mark_key_revocationlisted(const char *data, size_t size)
+{
+	return 0;
+}
+static inline int is_key_revocationlisted(struct pkcs7_message *pkcs7)
+{
+	return -ENOKEY;
+}
 #endif
 
 #ifdef CONFIG_IMA_BLACKLIST_KEYRING

@@ -55,6 +55,15 @@ static __init void uefi_blacklist_binary(const char *source,
 	uefi_blacklist_hash(source, data, len, "bin:", 4);
 }
 
+/*
+ * Revocationlist the X509 cert
+ */
+static __init void uefi_revocationlist_x509(const char *source,
+					    const void *data, size_t len)
+{
+	mark_key_revocationlisted(data, len);
+}
+
 /*
  * Return the appropriate handler for particular signature list types found in
  * the UEFI db and MokListRT tables.

@@ -76,5 +85,7 @@ __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
 		return uefi_blacklist_x509_tbs;
 	if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0)
 		return uefi_blacklist_binary;
+	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
+		return uefi_revocationlist_x509;
 	return 0;
 }