KEYS: Generalise system_verify_data() to provide access to internal content

Generalise system_verify_data() to provide access to internal content
through a callback.  This allows all the PKCS#7 stuff to be hidden inside
this function and removed from the PE file parser and the PKCS#7 test key.

If external content is not required, NULL should be passed as data to the
function.  If the callback is not required, that can be set to NULL.

The function is now called verify_pkcs7_signature() to contrast with
verify_pefile_signature() and the definitions of both have been moved into
linux/verification.h along with the key_being_used_for enum.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 50 insertions, 0 deletions

diff --git a/include/linux/verification.h b/include/linux/verification.h
new file mode 100644
index 000000000000..bb0fcf941cb7
--- /dev/null
+++ b/include/linux/verification.h
@@ -0,0 +1,50 @@
+/* Signature verification
+ *
+ * Copyright (C) 2014 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.
+ */
+
+#ifndef _LINUX_VERIFICATION_H
+#define _LINUX_VERIFICATION_H
+
+/*
+ * The use to which an asymmetric key is being put.
+ */
+enum key_being_used_for {
+	VERIFYING_MODULE_SIGNATURE,
+	VERIFYING_FIRMWARE_SIGNATURE,
+	VERIFYING_KEXEC_PE_SIGNATURE,
+	VERIFYING_KEY_SIGNATURE,
+	VERIFYING_KEY_SELF_SIGNATURE,
+	VERIFYING_UNSPECIFIED_SIGNATURE,
+	NR__KEY_BEING_USED_FOR
+};
+extern const char *const key_being_used_for[NR__KEY_BEING_USED_FOR];
+
+#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
+
+struct key;
+
+extern int verify_pkcs7_signature(const void *data, size_t len,
+				  const void *raw_pkcs7, size_t pkcs7_len,
+				  struct key *trusted_keys,
+				  int untrusted_error,
+				  enum key_being_used_for usage,
+				  int (*view_content)(void *ctx,
+						      const void *data, size_t len,
+						      size_t asn1hdrlen),
+				  void *ctx);
+
+#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
+extern int verify_pefile_signature(const void *pebuf, unsigned pelen,
+				   struct key *trusted_keys,
+				   enum key_being_used_for usage);
+#endif
+
+#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
+#endif /* _LINUX_VERIFY_PEFILE_H */