summaryrefslogtreecommitdiffstats
path: root/qemu/roms/ipxe/src/crypto/random_nz.c
diff options
context:
space:
mode:
Diffstat (limited to 'qemu/roms/ipxe/src/crypto/random_nz.c')
-rw-r--r--qemu/roms/ipxe/src/crypto/random_nz.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/crypto/random_nz.c b/qemu/roms/ipxe/src/crypto/random_nz.c
new file mode 100644
index 000000000..f1d2e187d
--- /dev/null
+++ b/qemu/roms/ipxe/src/crypto/random_nz.c
@@ -0,0 +1,76 @@
+/*
+ * 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., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * Random non-zero bytes
+ *
+ * The RSA algorithm requires the generation of random non-zero bytes,
+ * i.e. bytes in the range [0x01,0xff].
+ *
+ * This algorithm is designed to comply with ANS X9.82 Part 1-2006
+ * Section 9.2.1. This standard is not freely available, but most of
+ * the text appears to be shared with NIST SP 800-90, which can be
+ * downloaded from
+ *
+ * http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
+ *
+ * Where possible, references are given to both documents. In the
+ * case of any disagreement, ANS X9.82 takes priority over NIST SP
+ * 800-90. (In particular, note that some algorithms that are
+ * Approved by NIST SP 800-90 are not Approved by ANS X9.82.)
+ */
+
+#include <stddef.h>
+#include <stdint.h>
+#include <ipxe/rbg.h>
+#include <ipxe/random_nz.h>
+
+/**
+ * Get random non-zero bytes
+ *
+ * @v data Output buffer
+ * @v len Length of output buffer
+ * @ret rc Return status code
+ *
+ * This algorithm is designed to be isomorphic to the Simple Discard
+ * Method described in ANS X9.82 Part 1-2006 Section 9.2.1 (NIST SP
+ * 800-90 Section B.5.1.1).
+ */
+int get_random_nz ( void *data, size_t len ) {
+ uint8_t *bytes = data;
+ int rc;
+
+ while ( len ) {
+
+ /* Generate random byte */
+ if ( ( rc = rbg_generate ( NULL, 0, 0, bytes, 1 ) ) != 0 )
+ return rc;
+
+ /* Move to next byte if this byte is acceptable */
+ if ( *bytes != 0 ) {
+ bytes++;
+ len--;
+ }
+ }
+
+ return 0;
+}