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authorMichael Brown2012-02-20 22:26:23 +0100
committerMichael Brown2012-02-21 13:42:46 +0100
commit4e0effc6ad3b9f39859e259dd8f1f8af91c5b480 (patch)
tree2bf6c739f1e82bbb59d12010f0844734dd19e645 /src/crypto/rbg.c
parent[rng] Add ANS X9.82 mandatory start-up tests (diff)
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[rng] Add ANS X9.82 RBG wrapper functions
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/crypto/rbg.c')
-rw-r--r--src/crypto/rbg.c114
1 files changed, 114 insertions, 0 deletions
diff --git a/src/crypto/rbg.c b/src/crypto/rbg.c
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+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * RBG mechanism
+ *
+ * This mechanism is designed to comply with ANS X9.82 Part 4 (April
+ * 2011 Draft) Section 10. This standard is unfortunately not freely
+ * available.
+ *
+ * The chosen RBG design is that of a DRBG with a live entropy source
+ * with no conditioning function. Only a single security strength is
+ * supported. No seedfile is used since there may be no non-volatile
+ * storage available. The system UUID is used as the personalisation
+ * string.
+ */
+
+#include <stdint.h>
+#include <string.h>
+#include <ipxe/init.h>
+#include <ipxe/settings.h>
+#include <ipxe/uuid.h>
+#include <ipxe/crypto.h>
+#include <ipxe/drbg.h>
+#include <ipxe/rbg.h>
+
+/** The RBG */
+struct random_bit_generator rbg;
+
+/**
+ * Start up RBG
+ *
+ * @ret rc Return status code
+ *
+ * This is the RBG_Startup function defined in ANS X9.82 Part 4 (April
+ * 2011 Draft) Section 9.1.2.2.
+ */
+static int rbg_startup ( void ) {
+ union uuid uuid;
+ int len;
+ int rc;
+
+ /* Try to obtain system UUID for use as personalisation
+ * string, in accordance with ANS X9.82 Part 3-2007 Section
+ * 8.5.2. If no UUID is available, proceed without a
+ * personalisation string.
+ */
+ if ( ( len = fetch_uuid_setting ( NULL, &uuid_setting, &uuid ) ) < 0 ) {
+ rc = len;
+ DBGC ( &rbg, "RBG could not fetch personalisation string: "
+ "%s\n", strerror ( rc ) );
+ len = 0;
+ }
+
+ /* Instantiate DRBG */
+ if ( ( rc = drbg_instantiate ( &rbg.state, &uuid, len ) ) != 0 ) {
+ DBGC ( &rbg, "RBG could not instantiate DRBG: %s\n",
+ strerror ( rc ) );
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
+ * Shut down RBG
+ *
+ */
+static void rbg_shutdown ( void ) {
+
+ /* Uninstantiate DRBG */
+ drbg_uninstantiate ( &rbg.state );
+}
+
+/** RBG startup function */
+static void rbg_startup_fn ( void ) {
+
+ /* Start up RBG. There is no way to report an error at this
+ * stage, but a failed startup will result in an invalid DRBG
+ * that refuses to generate bits.
+ */
+ rbg_startup();
+}
+
+/** RBG shutdown function */
+static void rbg_shutdown_fn ( int booting __unused ) {
+
+ /* Shut down RBG */
+ rbg_shutdown();
+}
+
+/** RBG startup table entry */
+struct startup_fn startup_rbg __startup_fn ( STARTUP_NORMAL ) = {
+ .startup = rbg_startup_fn,
+ .shutdown = rbg_shutdown_fn,
+};