-/* mcookie.c -- Generates random numbers for xauth
+/*
+ * No copyright is claimed. This code is in the public domain; do with
+ * it what you wish.
+ *
+ * mcookie.c -- Generates random numbers for xauth
* Created: Fri Feb 3 10:42:48 1995 by faith@cs.unc.edu
* Revised: Fri Mar 19 07:48:01 1999 by faith@acm.org
* Public Domain 1995, 1999 Rickard E. Faith (faith@acm.org)
* This program comes with ABSOLUTELY NO WARRANTY.
- *
+ *
* This program gathers some random bits of data and used the MD5
* message-digest algorithm to generate a 128-bit hexadecimal number for
* use with xauth(1).
* gather 128 bits of random information, so the magic cookie generated
* will be considerably easier to guess than one might expect.
*
- * 1999-02-22 Arkadiusz Mi¶kiewicz <misiek@pld.ORG.PL>
+ * 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
* - added Native Language Support
* 1999-03-21 aeb: Added some fragments of code from Colin Plumb.
*
#include "c.h"
#include "md5.h"
#include "nls.h"
+#include "closestream.h"
+#include "randutils.h"
+#include "strutils.h"
+#include "xalloc.h"
+#include "all-io.h"
+
#include <fcntl.h>
#include <getopt.h>
#include <stddef.h>
#include <sys/time.h>
#include <unistd.h>
-#define BUFFERSIZE 4096
-
-struct rngs {
- const char *path;
- int minlength, maxlength;
-} rngs[] = {
- {"/dev/random", 16, 16}, /* 16 bytes = 128 bits suffice */
- {"/proc/interrupts", 0, 0},
- {"/proc/slabinfo", 0, 0},
- {"/proc/stat", 0, 0},
- {"/dev/urandom", 32, 64},
+enum {
+ BUFFERSIZE = 4096,
+ RAND_BYTES = 128
};
-#define RNGS (sizeof(rngs)/sizeof(struct rngs))
+struct mcookie_control {
+ struct UL_MD5Context ctx;
+ char **files;
+ size_t nfiles;
+ uint64_t maxsz;
+
+ unsigned int verbose:1;
+};
/* The basic function to hash a file */
-static off_t hash_file(struct MD5Context *ctx, int fd)
+static uint64_t hash_file(struct mcookie_control *ctl, int fd)
{
- off_t count = 0;
- ssize_t r;
unsigned char buf[BUFFERSIZE];
+ uint64_t wanted, count;
+
+ wanted = ctl->maxsz ? ctl->maxsz : sizeof(buf);
- while ((r = read(fd, buf, sizeof(buf))) > 0) {
- MD5Update(ctx, buf, r);
+ for (count = 0; count < wanted; ) {
+ size_t rdsz = sizeof(buf);
+ ssize_t r;
+
+ if (wanted - count < rdsz)
+ rdsz = wanted - count;
+
+ r = read_all(fd, (char *) buf, rdsz);
+ if (r <= 0)
+ break;
+ ul_MD5Update(&ctl->ctx, buf, r);
count += r;
}
/* Separate files with a null byte */
buf[0] = '\0';
- MD5Update(ctx, buf, 1);
+ ul_MD5Update(&ctl->ctx, buf, 1);
return count;
}
-static void __attribute__ ((__noreturn__)) usage(FILE * out)
+static void __attribute__((__noreturn__)) usage(void)
{
- fprintf(out, _("Usage: %s [options]\n"),
- program_invocation_short_name);
+ FILE *out = stdout;
+ fputs(USAGE_HEADER, out);
+ fprintf(out, _(" %s [options]\n"), program_invocation_short_name);
+
+ fputs(USAGE_SEPARATOR, out);
+ fputs(_("Generate magic cookies for xauth.\n"), out);
+
+ fputs(USAGE_OPTIONS, out);
+ fputs(_(" -f, --file <file> use file as a cookie seed\n"), out);
+ fputs(_(" -m, --max-size <num> limit how much is read from seed files\n"), out);
+ fputs(_(" -v, --verbose explain what is being done\n"), out);
+
+ fputs(USAGE_SEPARATOR, out);
+ fprintf(out, USAGE_HELP_OPTIONS(23));
+
+ fputs(USAGE_ARGUMENTS, out);
+ fprintf(out, USAGE_ARG_SIZE(_("<num>")));
+
+ fprintf(out, USAGE_MAN_TAIL("mcookie(1)"));
+
+ exit(EXIT_SUCCESS);
+}
+
+static void randomness_from_files(struct mcookie_control *ctl)
+{
+ size_t i;
+
+ for (i = 0; i < ctl->nfiles; i++) {
+ const char *fname = ctl->files[i];
+ size_t count;
+ int fd;
+
+ if (*fname == '-' && !*(fname + 1))
+ fd = STDIN_FILENO;
+ else
+ fd = open(fname, O_RDONLY);
- fprintf(out, _("\nOptions:\n"
- " -f, --file=FILE use file as a cookie seed\n"
- " -v, --verbose explain what is being done\n"
- " -V, --version output version information and exit\n"
- " -h, --help display this help and exit\n"));
+ if (fd < 0) {
+ warn(_("cannot open %s"), fname);
+ } else {
+ count = hash_file(ctl, fd);
+ if (ctl->verbose)
+ fprintf(stderr,
+ P_("Got %zu byte from %s\n",
+ "Got %zu bytes from %s\n", count),
+ count, fname);
- exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+ if (fd != STDIN_FILENO && close(fd))
+ err(EXIT_FAILURE, _("closing %s failed"), fname);
+ }
+ }
}
int main(int argc, char **argv)
{
+ struct mcookie_control ctl = { .verbose = 0 };
size_t i;
- struct MD5Context ctx;
- unsigned char digest[16];
- unsigned char buf[BUFFERSIZE];
- int fd;
+ unsigned char digest[UL_MD5LENGTH];
+ unsigned char buf[RAND_BYTES];
int c;
- pid_t pid;
- char *file = NULL;
- int verbose = 0;
- int r;
- struct timeval tv;
- struct timezone tz;
static const struct option longopts[] = {
{"file", required_argument, NULL, 'f'},
+ {"max-size", required_argument, NULL, 'm'},
{"verbose", no_argument, NULL, 'v'},
{"version", no_argument, NULL, 'V'},
{"help", no_argument, NULL, 'h'},
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
+ close_stdout_atexit();
- while ((c =
- getopt_long(argc, argv, "f:vVh", longopts, NULL)) != -1)
+ while ((c = getopt_long(argc, argv, "f:m:vVh", longopts, NULL)) != -1) {
switch (c) {
case 'v':
- verbose = 1;
+ ctl.verbose = 1;
break;
case 'f':
- file = optarg;
+ if (!ctl.files)
+ ctl.files = xmalloc(sizeof(char *) * argc);
+ ctl.files[ctl.nfiles++] = optarg;
break;
+ case 'm':
+ ctl.maxsz = strtosize_or_err(optarg,
+ _("failed to parse length"));
+ break;
+
case 'V':
- printf(_("%s from %s\n"),
- program_invocation_short_name,
- PACKAGE_STRING);
- return EXIT_SUCCESS;
+ print_version(EXIT_SUCCESS);
case 'h':
- usage(stdout);
+ usage();
default:
- usage(stderr);
+ errtryhelp(EXIT_FAILURE);
}
+ }
- MD5Init(&ctx);
- gettimeofday(&tv, &tz);
- MD5Update(&ctx, (unsigned char *) &tv, sizeof(tv));
-
- pid = getppid();
- MD5Update(&ctx, (unsigned char *) &pid, sizeof(pid));
- pid = getpid();
- MD5Update(&ctx, (unsigned char *) &pid, sizeof(pid));
-
- if (file) {
- int count = 0;
-
- if (file[0] == '-' && !file[1])
- fd = STDIN_FILENO;
- else
- fd = open(file, O_RDONLY);
-
- if (fd < 0) {
- warn(_("Could not open %s"), file);
- } else {
- count = hash_file(&ctx, fd);
- if (verbose)
- fprintf(stderr,
- _("Got %d bytes from %s\n"), count,
- file);
+ if (ctl.maxsz && ctl.nfiles == 0)
+ warnx(_("--max-size ignored when used without --file"));
- if (fd != STDIN_FILENO)
- if (close(fd))
- err(EXIT_FAILURE,
- _("closing %s failed"), file);
- }
- }
+ ul_MD5Init(&ctl.ctx);
+ randomness_from_files(&ctl);
+ free(ctl.files);
- for (i = 0; i < RNGS; i++) {
- if ((fd = open(rngs[i].path, O_RDONLY | O_NONBLOCK)) >= 0) {
- int count = sizeof(buf);
-
- if (rngs[i].maxlength && count > rngs[i].maxlength)
- count = rngs[i].maxlength;
- r = read(fd, buf, count);
- if (r > 0)
- MD5Update(&ctx, buf, r);
- else
- r = 0;
- close(fd);
- if (verbose)
- fprintf(stderr,
- _("Got %d bytes from %s\n"), r,
- rngs[i].path);
- if (rngs[i].minlength && r >= rngs[i].minlength)
- break;
- } else if (verbose)
- warn(_("Could not open %s"), rngs[i].path);
- }
+ ul_random_get_bytes(&buf, RAND_BYTES);
+ ul_MD5Update(&ctl.ctx, buf, RAND_BYTES);
+ if (ctl.verbose)
+ fprintf(stderr, P_("Got %d byte from %s\n",
+ "Got %d bytes from %s\n", RAND_BYTES),
+ RAND_BYTES, random_tell_source());
- MD5Final(digest, &ctx);
- for (i = 0; i < 16; i++)
+ ul_MD5Final(digest, &ctl.ctx);
+ for (i = 0; i < UL_MD5LENGTH; i++)
printf("%02x", digest[i]);
putchar('\n');
- /*
- * The following is important for cases like disk full,
- * so shell scripts can bomb out properly rather than
- * think they succeeded.
- */
- if (fflush(stdout) < 0 || fclose(stdout) < 0)
- return EXIT_FAILURE;
-
return EXIT_SUCCESS;
}
projects / thirdparty / util-linux.git / blobdiff