-/* 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 <stdio.h>
#include <stdlib.h>
-#include <fcntl.h>
-#include "md5.h"
#include <sys/time.h>
#include <unistd.h>
-#include "nls.h"
-#include <getopt.h>
-#include "c.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))
-int Verbose = 0;
+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];
-
- while ((r = read(fd, buf, sizeof(buf))) > 0) {
- MD5Update(ctx, buf, r);
- count += r;
- }
- /* Separate files with a null byte */
- buf[0] = 0;
- MD5Update(ctx, buf, 1);
- return count;
+ unsigned char buf[BUFFERSIZE];
+ uint64_t wanted, count;
+
+ wanted = ctl->maxsz ? ctl->maxsz : sizeof(buf);
+
+ 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';
+ 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));
- 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"));
+ fputs(USAGE_ARGUMENTS, out);
+ fprintf(out, USAGE_ARG_SIZE(_("<num>")));
- exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+ fprintf(out, USAGE_MAN_TAIL("mcookie(1)"));
+
+ exit(EXIT_SUCCESS);
}
-int main( int argc, char **argv )
+
+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);
+
+ 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);
+
+ if (fd != STDIN_FILENO && close(fd))
+ err(EXIT_FAILURE, _("closing %s failed"), fname);
+ }
+ }
+}
+
+int main(int argc, char **argv)
{
- size_t i;
- struct MD5Context ctx;
- unsigned char digest[16];
- unsigned char buf[BUFFERSIZE];
- int fd;
- int c;
- pid_t pid;
- char *file = NULL;
- int r;
- struct timeval tv;
- struct timezone tz;
-
- static const struct option longopts[] = {
- {"file", required_argument, NULL, 'f'},
- {"verbose", no_argument, NULL, 'v'},
- {"version", no_argument, NULL, 'V'},
- {"help", no_argument, NULL, 'h'},
- {NULL, 0, NULL, 0}
- };
-
- setlocale(LC_ALL, "");
- bindtextdomain(PACKAGE, LOCALEDIR);
- textdomain(PACKAGE);
-
- while ((c = getopt_long(argc, argv, "f:vVh", longopts, NULL)) != -1)
- switch (c) {
- case 'v':
- Verbose = 1;
- break;
- case 'f':
- file = optarg;
- break;
- case 'V':
- printf(_("%s from %s\n"), program_invocation_short_name,
- PACKAGE_STRING);
- return EXIT_SUCCESS;
- case 'h':
- usage(stdout);
- default:
- usage(stderr);
- }
-
- 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 (fd != STDIN_FILENO)
- if(close( fd ))
- err(EXIT_FAILURE, _("closing %s failed"), file);
- }
- }
-
- 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 );
- }
-
- MD5Final( digest, &ctx );
- for (i = 0; i < 16; 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;
+ struct mcookie_control ctl = { .verbose = 0 };
+ size_t i;
+ unsigned char digest[UL_MD5LENGTH];
+ unsigned char buf[RAND_BYTES];
+ int c;
+
+ 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'},
+ {NULL, 0, NULL, 0}
+ };
+
+ setlocale(LC_ALL, "");
+ bindtextdomain(PACKAGE, LOCALEDIR);
+ textdomain(PACKAGE);
+ close_stdout_atexit();
+
+ while ((c = getopt_long(argc, argv, "f:m:vVh", longopts, NULL)) != -1) {
+ switch (c) {
+ case 'v':
+ ctl.verbose = 1;
+ break;
+ case 'f':
+ 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':
+ print_version(EXIT_SUCCESS);
+ case 'h':
+ usage();
+ default:
+ errtryhelp(EXIT_FAILURE);
+ }
+ }
+
+ if (ctl.maxsz && ctl.nfiles == 0)
+ warnx(_("--max-size ignored when used without --file"));
+
+ ul_MD5Init(&ctl.ctx);
+ randomness_from_files(&ctl);
+ free(ctl.files);
+
+ 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());
+
+ ul_MD5Final(digest, &ctl.ctx);
+ for (i = 0; i < UL_MD5LENGTH; i++)
+ printf("%02x", digest[i]);
+ putchar('\n');
+
+ return EXIT_SUCCESS;
}
projects / thirdparty / util-linux.git / blobdiff