mirror of
https://github.com/troglobit/finit.git
synced 2026-10-01 05:22:48 +07:00
Joachim Nilsson
a33478d563
For embedded systems with no initial random seed, usually stored in /var/lib/urandom/urandom-seed on desktops, servers and laptops, we now provide an initial seed file using a built-in PRNG. Also, let the configure script default to *enable* the random seeding at boot, granted the urandom plugin is enabled. We should encourage users to properly seed their random, for security reasons. Moreover, the plugin did not properly regenerate the random seed on reboot, or shutdown, this patch also rectifies that problem. Signed-off-by: Joachim Nilsson <troglobit@gmail.com>
102 lines
2.6 KiB
C
102 lines
2.6 KiB
C
/* Setup random seed
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*
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* Copyright (c) 2012 Joachim Nilsson <troglobit@gmail.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include <unistd.h>
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#include <sys/stat.h>
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#include <sys/time.h> /* gettimeofday() */
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#include <sys/types.h>
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#include "../config.h"
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#include "../finit.h"
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#include "../helpers.h"
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#include "../plugin.h"
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#include "libite/lite.h"
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static void setup(void *UNUSED(arg))
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{
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#ifdef RANDOMSEED
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if (!fexist(RANDOMSEED)) {
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int ret = 1;
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FILE *fp;
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print_desc("Bootstrapping random seed", NULL);
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umask(077);
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fp = fopen(RANDOMSEED, "w");
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if (fp) {
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int iter = 128;
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struct timeval tv;
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gettimeofday(&tv, NULL);
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srandom(tv.tv_sec % 3600);
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while (iter--) {
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uint32_t i, prng = random();
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for (i = 0; i < sizeof(prng); i++)
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fputc((prng >> (i * CHAR_BIT)) & UCHAR_MAX, fp);
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}
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ret = fclose(fp);
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}
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print_result(ret);
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umask(0);
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}
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print_desc("Initializing random number generator", NULL);
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print_result(512 != copyfile(RANDOMSEED, "/dev/urandom", 0, 0));
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#endif
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}
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static void save(void *UNUSED(arg))
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{
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#ifdef RANDOMSEED
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umask(077);
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print_desc("Saving random seed", NULL);
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print_result(512 != copyfile("/dev/urandom", RANDOMSEED, 512, 0));
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umask(0);
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#endif
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}
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static plugin_t plugin = {
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.name = "urandom",
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.hook[HOOK_BASEFS_UP] = { .cb = setup },
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.hook[HOOK_SHUTDOWN] = { .cb = save },
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.depends = { "bootmisc", }
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};
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PLUGIN_INIT(plugin_init)
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{
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plugin_register(&plugin);
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}
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PLUGIN_EXIT(plugin_exit)
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{
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plugin_unregister(&plugin);
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}
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/**
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* Local Variables:
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* version-control: t
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* indent-tabs-mode: t
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* c-file-style: "linux"
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* End:
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*/
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