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-rw-r--r--fakerandom.c56
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+/*
+
+ Copyright (c) 2017 Samuel Lidén Borell <samuel@kodafritt.se>
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE.
+
+*/
+
+#include <fcntl.h>
+#include <linux/random.h>
+#include <sys/ioctl.h>
+#include <stdio.h>
+
+int main(int argc, const char **argv)
+{
+ int fd, res, ent;
+
+ (void) argv;
+ if (argc > 1) {
+ printf("usage: fakerandom\n\n"
+ "Increases the entropy counter, without actually adding any entropy.\n"
+ "Obviously this is NOT secure. Do not use on production systems!\n\n");
+ return 0;
+ }
+
+ fd = open("/dev/random", O_WRONLY);
+ if (fd < 0) {
+ perror("failed to open /dev/random");
+ return 1;
+ }
+
+ ent = 0x1000000;
+ res = ioctl(fd, RNDADDTOENTCNT, &ent);
+ if (res < 0) {
+ perror("failed to add fake entropy");
+ return 1;
+ }
+ return 0;
+}
+