tools uapi headers: add linux/module_signature.h

This header is going to be used from scripts/sign-file.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>

tools/include/uapi/linux/module_signature.h

@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * Module signature handling.
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#ifndef _UAPI_LINUX_MODULE_SIGNATURE_H
+#define _UAPI_LINUX_MODULE_SIGNATURE_H
+
+#include <linux/types.h>
+
+/* In stripped ARM and x86-64 modules, ~ is surprisingly rare. */
+#define MODULE_SIGNATURE_MARKER "~Module signature appended~\n"
+
+enum module_signature_type {
+	MODULE_SIGNATURE_TYPE_PKCS7 = 2,	/* Signature in PKCS#7 message */
+};
+
+/*
+ * Module signature information block.
+ *
+ * The constituents of the signature section are, in order:
+ *
+ *	- Signer's name
+ *	- Key identifier
+ *	- Signature data
+ *	- Information block
+ */
+struct module_signature {
+	__u8	algo;		/* Public-key crypto algorithm [0] */
+	__u8	hash;		/* Digest algorithm [0] */
+	__u8	id_type;	/* Key identifier type [enum module_signature_type] */
+	__u8	signer_len;	/* Length of signer's name [0] */
+	__u8	key_id_len;	/* Length of key identifier [0] */
+	__u8	__pad[3];
+	__be32	sig_len;	/* Length of signature data */
+};
+
+#endif /* _UAPI_LINUX_MODULE_SIGNATURE_H */