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Diffstat (limited to 'programs/ranbits/ranbits.c')
-rw-r--r-- | programs/ranbits/ranbits.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/programs/ranbits/ranbits.c b/programs/ranbits/ranbits.c new file mode 100644 index 000000000..7b9a0f76e --- /dev/null +++ b/programs/ranbits/ranbits.c @@ -0,0 +1,146 @@ +/* + * random bit generation for scripts, control files, etc. + * Copyright (C) 1998, 1999, 2000 Henry Spencer. + * + * 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 2 of the License, or (at your + * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>. + * + * 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. + * + * RCSID $Id: ranbits.c,v 1.1 2004/03/15 20:35:30 as Exp $ + */ + +#include <sys/types.h> +#include <sys/stat.h> +#include <stdio.h> +#include <limits.h> +#include <errno.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <getopt.h> +#include <fcntl.h> +#include <netinet/in.h> +#include <freeswan.h> + +#ifndef DEVICE +#define DEVICE "/dev/random" +#endif +#ifndef QDEVICE +#define QDEVICE "/dev/urandom" +#endif +#ifndef MAXBITS +#define MAXBITS 20000 +#endif + +char usage[] = "Usage: ranbits [--quick] [--continuous] [--bytes] nbits"; +struct option opts[] = { + {"quick", 0, NULL, 'q',}, + {"continuous", 0, NULL, 'c',}, + {"bytes", 0, NULL, 'b',}, + {"help", 0, NULL, 'h',}, + {"version", 0, NULL, 'v',}, + {0, 0, NULL, 0,} +}; +int quick = 0; /* quick and dirty? */ +char format = 'h'; /* datatot() format code */ +int isbytes = 0; /* byte count rather than bits? */ + +char me[] = "ipsec ranbits"; /* for messages */ + +char buf[MAXBITS/CHAR_BIT]; +char outbuf[3*sizeof(buf)]; + +int main(int argc, char *argv[]) +{ + int opt; + extern int optind; + int errflg = 0; + int nbits; + size_t nbytes; + char *devname; + int dev; + size_t ndone; + size_t nneeded; + ssize_t got; + + while ((opt = getopt_long(argc, argv, "", opts, NULL)) != EOF) + switch (opt) { + case 'q': /* quick and dirty randomness */ + quick = 1; + break; + case 'c': /* continuous hex, no underscores */ + format = 'x'; + break; + case 'b': /* byte count, not bit count */ + isbytes = 1; + break; + case 'h': /* help */ + printf("%s\n", usage); + exit(0); + break; + case 'v': /* version */ + printf("%s %s\n", me, ipsec_version_code()); + exit(0); + break; + case '?': + default: + errflg = 1; + break; + } + if (errflg || optind != argc-1) { + fprintf(stderr, "%s\n", usage); + exit(2); + } + + nbits = atoi(argv[optind]); + if (isbytes) + nbits *= CHAR_BIT; + if (nbits <= 0) { + fprintf(stderr, "%s: invalid bit count (%d)\n", me, nbits); + exit(1); + } + if (nbits > MAXBITS) { + fprintf(stderr, "%s: overlarge bit count (max %d)\n", me, + MAXBITS); + exit(1); + } + nbytes = (size_t)(nbits + CHAR_BIT - 1) / CHAR_BIT; + + devname = (quick) ? QDEVICE : DEVICE; + dev = open(devname, 0); + if (dev < 0) { + fprintf(stderr, "%s: could not open %s (%s)\n", me, + devname, strerror(errno)); + exit(1); + } + + ndone = 0; + while (ndone < nbytes) { + got = read(dev, buf + ndone, nbytes - ndone); + if (got < 0) { + fprintf(stderr, "%s: read error on %s (%s)\n", me, + devname, strerror(errno)); + exit(1); + } + if (got == 0) { + fprintf(stderr, "%s: eof on %s!?!\n", me, devname); + exit(1); + } + ndone += got; + } + + nneeded = datatot(buf, nbytes, format, outbuf, sizeof(outbuf)); + if (nneeded > sizeof(outbuf)) { + fprintf(stderr, "%s: buffer overflow (need %ld bytes)?!?\n", + me, (long)nneeded); + exit(1); + } + printf("%s\n", outbuf); + exit(0); +} |