1 files changed, 27 insertions, 31 deletions

diff --git a/lib/oid_registry.c b/lib/oid_registry.c
index 0bcac6ccb1b2..9b757a117f09 100644
--- a/lib/oid_registry.c
+++ b/lib/oid_registry.c
@@ -1,12 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /* ASN.1 Object identifier (OID) registry
  *
  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public Licence
- * as published by the Free Software Foundation; either version
- * 2 of the Licence, or (at your option) any later version.
  */
 
 #include <linux/module.h>
@@ -15,6 +11,7 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/bug.h>
+#include <linux/asn1.h>
 #include "oid_registry_data.c"
 
 MODULE_DESCRIPTION("OID Registry");
@@ -96,15 +93,38 @@ enum OID look_up_OID(const void *data, size_t datasize)
 }
 EXPORT_SYMBOL_GPL(look_up_OID);
 
+/**
+ * parse_OID - Parse an OID from a bytestream
+ * @data: Binary representation of the header + OID
+ * @datasize: Size of the binary representation
+ * @oid: Pointer to oid to return result
+ *
+ * Parse an OID from a bytestream that holds the OID in the format
+ * ASN1_OID | length | oid. The length indicator must equal to datasize - 2.
+ * -EBADMSG is returned if the bytestream is too short.
+ */
+int parse_OID(const void *data, size_t datasize, enum OID *oid)
+{
+	const unsigned char *v = data;
+
+	/* we need 2 bytes of header and at least 1 byte for oid */
+	if (datasize < 3 || v[0] != ASN1_OID || v[1] != datasize - 2)
+		return -EBADMSG;
+
+	*oid = look_up_OID(data + 2, datasize - 2);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(parse_OID);
+
 /*
- * sprint_OID - Print an Object Identifier into a buffer
+ * sprint_oid - Print an Object Identifier into a buffer
  * @data: The encoded OID to print
  * @datasize: The size of the encoded OID
  * @buffer: The buffer to render into
  * @bufsize: The size of the buffer
  *
  * The OID is rendered into the buffer in "a.b.c.d" format and the number of
- * bytes is returned.  -EBADMSG is returned if the data could not be intepreted
+ * bytes is returned.  -EBADMSG is returned if the data could not be interpreted
  * and -ENOBUFS if the buffer was too small.
  */
 int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize)
@@ -126,7 +146,6 @@ int sprint_oid(const void *data, size_t datasize, char *buffer, size_t bufsize)
 	bufsize -= count;
 
 	while (v < end) {
-		num = 0;
 		n = *v++;
 		if (!(n & 0x80)) {
 			num = n;
@@ -154,26 +173,3 @@ bad:
 	return -EBADMSG;
 }
 EXPORT_SYMBOL_GPL(sprint_oid);
-
-/**
- * sprint_OID - Print an Object Identifier into a buffer
- * @oid: The OID to print
- * @buffer: The buffer to render into
- * @bufsize: The size of the buffer
- *
- * The OID is rendered into the buffer in "a.b.c.d" format and the number of
- * bytes is returned.
- */
-int sprint_OID(enum OID oid, char *buffer, size_t bufsize)
-{
-	int ret;
-
-	BUG_ON(oid >= OID__NR);
-
-	ret = sprint_oid(oid_data + oid_index[oid],
-			 oid_index[oid + 1] - oid_index[oid],
-			 buffer, bufsize);
-	BUG_ON(ret == -EBADMSG);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(sprint_OID);