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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 17:20:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 17:20:00 +0000
commit8daa83a594a2e98f39d764422bfbdbc62c9efd44 (patch)
tree4099e8021376c7d8c05bdf8503093d80e9c7bad0 /lib/util/genrand.c
parentInitial commit. (diff)
downloadsamba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.tar.xz
samba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.zip
Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/util/genrand.c')
-rw-r--r--lib/util/genrand.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/lib/util/genrand.c b/lib/util/genrand.c
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+++ b/lib/util/genrand.c
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+/*
+ Unix SMB/CIFS implementation.
+
+ Functions to create reasonable random numbers for crypto use.
+
+ Copyright (C) Jeremy Allison 2001
+
+ 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 3 of the License, or
+ (at your option) 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "replace.h"
+#include "lib/util/fault.h"
+#include "lib/util/genrand.h"
+
+#include <gnutls/gnutls.h>
+#include <gnutls/crypto.h>
+
+/*
+ * Details about the GnuTLS CSPRNG:
+ *
+ * https://nikmav.blogspot.com/2017/03/improving-by-simplifying-gnutls-prng.html
+ */
+
+
+_NORETURN_ static void genrand_panic(int err,
+ const char *location,
+ const char *func)
+{
+ char buf[200];
+ snprintf(buf, sizeof(buf),
+ "%s:%s: GnuTLS could not generate a random buffer: %s [%d]\n",
+ location, func, gnutls_strerror_name(err), err);
+ smb_panic(buf);
+}
+
+
+_PUBLIC_ void generate_random_buffer(uint8_t *out, size_t len)
+{
+ /* Random number generator for temporary keys. */
+ int ret = gnutls_rnd(GNUTLS_RND_RANDOM, out, len);
+ if (ret != 0) {
+ genrand_panic(ret, __location__, __func__);
+ }
+}
+
+_PUBLIC_ void generate_secret_buffer(uint8_t *out, size_t len)
+{
+ /*
+ * Random number generator for long term keys.
+ *
+ * The key generator, will re-seed after a fixed amount of bytes is
+ * generated (typically less than the nonce), and will also re-seed
+ * based on time, i.e., after few hours of operation without reaching
+ * the limit for a re-seed. For its re-seed it mixes data obtained
+ * from the OS random device with the previous key.
+ */
+ int ret = gnutls_rnd(GNUTLS_RND_KEY, out, len);
+ if (ret != 0) {
+ genrand_panic(ret, __location__, __func__);
+ }
+}
+
+_PUBLIC_ void generate_nonce_buffer(uint8_t *out, size_t len)
+{
+ /*
+ * Random number generator for nonce and initialization vectors.
+ *
+ * The nonce generator will reseed after outputting a fixed amount of
+ * bytes (typically few megabytes), or after few hours of operation
+ * without reaching the limit has passed.
+ */
+ int ret = gnutls_rnd(GNUTLS_RND_NONCE, out, len);
+ if (ret != 0) {
+ genrand_panic(ret, __location__, __func__);
+ }
+}