+++ /dev/null
-/* -*-c-*-
- *
- * $Id: keygen.c,v 1.6 2003/09/17 13:17:23 mdw Exp $
- *
- * Key generation
- *
- * (c) 1998 EBI
- */
-
-/*----- Licensing notice --------------------------------------------------*
- *
- * This file is part of `become'
- *
- * `Become' 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.
- *
- * `Become' 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with `become'; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- */
-
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: keygen.c,v $
- * Revision 1.6 2003/09/17 13:17:23 mdw
- * Make it build\!
- *
- * Revision 1.5 1998/01/12 16:46:05 mdw
- * Fix copyright date.
- *
- * Revision 1.4 1997/12/08 15:29:27 mdw
- * Major update: make random number sources configurable. Generate
- * warnings if there isn't enough randomness available.
- *
- * Revision 1.3 1997/09/17 15:29:28 mdw
- * Mix the noise from the key timings with some other environmental noise
- * (obtained from `noise_acquire') for a little bit more randomness.
- *
- * Revision 1.2 1997/08/04 10:24:23 mdw
- * Sources placed under CVS control.
- *
- * Revision 1.1 1997/07/21 13:47:48 mdw
- * Initial revision
- *
- */
-
-/*----- Header files ------------------------------------------------------*/
-
-/* --- ANSI headers --- */
-
-#include <ctype.h>
-#include <errno.h>
-#include <signal.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <time.h>
-
-/* --- Unix headers --- */
-
-#include <sys/types.h>
-#include <sys/time.h>
-#include <fcntl.h>
-
-#include <termios.h>
-#include <unistd.h>
-
-/* --- Local headers --- */
-
-#include "config.h"
-#include "mdwopt.h"
-#include "noise.h"
-#include "rand.h"
-#include "tx.h"
-#include "utils.h"
-
-/*----- Static variables --------------------------------------------------*/
-
-static struct termios kg__raw, kg__old; /* Terminal settings */
-static int kg__tty; /* File handle for the terminal */
-static FILE *kg__ttyfp; /* Stream pointer for terminal */
-static unsigned int kg__flags; /* Various interesting flags */
-
-enum {
- kgFlag__cbreak = 1 /* Terminal is in cbreak mode */
-};
-
-/*----- Main code ---------------------------------------------------------*/
-
-/* --- @kg__cbreak@ --- *
- *
- * Arguments: ---
- *
- * Returns: ---
- *
- * Use: Makes the terminal return characters as soon as they're
- * asked for.
- */
-
-void kg__cbreak(void)
-{
- /* --- Don't do this if I don't have to --- */
-
- if (kg__flags & kgFlag__cbreak)
- return;
-
- /* --- Fetch the old attributes, and remember them --- */
-
- if (tcgetattr(kg__tty, &kg__old))
- die("couldn't read terminal attributes: %s", strerror(errno));
- memcpy(&kg__raw, &kg__old, sizeof(kg__raw));
-
- /* --- Now modify them for raw mode --- */
-
- kg__raw.c_lflag &= ~(ICANON | ECHO);
- kg__raw.c_cc[VTIME] = 0;
- kg__raw.c_cc[VMIN] = 1;
-
- /* --- Remember the new state, and away we go --- */
-
- kg__flags |= kgFlag__cbreak;
- if (tcsetattr(kg__tty, TCSAFLUSH, &kg__raw))
- die("couldn't set terminal attributes: %s", strerror(errno));
-}
-
-/* --- @kg__crepair@ --- *
- *
- * Arguments: ---
- *
- * Returns: ---
- *
- * Use: Unbreaks a cbroken tty. Obvious, innit?
- */
-
-static void kg__crepair(void)
-{
- /* --- Don't do this if I don't have to --- */
-
- if (~kg__flags & kgFlag__cbreak)
- return;
-
- /* --- Reset the old attributes --- */
-
- tcsetattr(kg__tty, TCSAFLUSH, &kg__old);
- kg__flags &= ~kgFlag__cbreak;
-}
-
-/* --- @kg__signal@ --- *
- *
- * Arguments: @int sig@ = signal number
- *
- * Returns: ---
- *
- * Use: Tidies up if I get a signal.
- */
-
-static void kg__signal(int sig)
-{
- kg__crepair();
- signal(sig, SIG_DFL);
- raise(sig);
-}
-
-/* --- @kgFmt__binary@ --- *
- *
- * Arguments: @unsigned char *k@ = pointer to key buffer
- * @size_t bits@ = number of bits to write
- * @FILE *fp@ = stream to write on
- *
- * Returns: ---
- *
- * Use: Writes bits on a stream.
- */
-
-static void kgFmt__binary(unsigned char *k, size_t bits, FILE *fp)
-{
- fwrite(k, 1, bits / 8, fp);
-}
-
-/* --- @kgFmt__base64@ --- *
- *
- * Arguments: @unsigned char *k@ = pointer to key buffer
- * @size_t bits@ = number of bits to write
- * @FILE *fp@ = stream to write on
- *
- * Returns: ---
- *
- * Use: Writes bits on a stream in an encoded way.
- */
-
-static void kgFmt__base64(unsigned char *k, size_t bits, FILE *fp)
-{
- static const char xlt[64] = { "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
- "abcdefghijklmnopqrstuvwxyz"
- "0123456789+/" };
- unsigned long b;
- int ll = 0;
-
- while (bits > 24) {
- b = ((k[0] & 0xffu) << 16) | ((k[1] & 0xffu) << 8) | (k[2] & 0xffu);
- k += 3;
- bits -= 24;
- putc(xlt[(b >> 18) & 0x3fu], fp);
- putc(xlt[(b >> 12) & 0x3fu], fp);
- putc(xlt[(b >> 6) & 0x3fu], fp);
- putc(xlt[(b >> 0) & 0x3fu], fp);
- if ((ll += 4) > 70) {
- putc('\n', fp);
- ll = 0;
- }
- }
-
- b = 0;
- switch (bits) {
- case 24:
- b = *k++ & 0xffu;
- case 16:
- b = (b << 8) | (*k++ & 0xffu);
- case 8:
- b = (b << 8) | (*k++ & 0xffu);
- }
- b <<= (24 - bits);
- putc(xlt[(b >> 18) & 0x3fu], fp);
- putc(xlt[(b >> 12) & 0x3fu], fp);
- switch (bits) {
- case 24:
- putc(xlt[(b >> 6) & 0x3fu], fp);
- putc(xlt[(b >> 0) & 0x3fu], fp);
- break;
- case 16:
- putc(xlt[(b >> 6) & 0x3fu], fp);
- putc('=', fp);
- break;
- case 8:
- fputs("==", fp);
- break;
- }
-
- putc('\n', fp);
-}
-
-/* --- @kg__gen@ --- *
- *
- * Arguments: @unsigned char *ui@ = pointer to array to fill in
- * @size_t sz@ = number of bits to generate
- *
- * Returns: ---
- *
- * Use: Uses key timings to generate random numbers. Maybe.
- */
-
-static void kg__gen(unsigned char *ui, size_t sz)
-{
- int bits = 32 < sz ? 32 : sz;
- size_t wsz = (sz + 31u) & ~31u;
- unsigned long last, ldiff = 0;
- unsigned long a = 0;
- unsigned long fact = 1000000 / CLOCKS_PER_SEC;
-
- fprintf(kg__ttyfp,
-"I need to get %lu random bits; I'll do this by timing your keypresses.\n"
-"Please type some arbitrary text until I say `done'.\n",
- (unsigned long)sz);
-
- {
- struct timeval tv;
- gettimeofday(&tv, 0);
- last = tv.tv_usec / fact + tv.tv_sec * fact;
- }
-
- while (sz) {
- int useful;
- uint_32 orr, xor;
-
- /* --- Print current status --- */
-
- fprintf(kg__ttyfp, "\r%5lu...", (unsigned long)sz);
- fflush(kg__ttyfp);
-
- /* --- Read the next character --- */
-
- {
- char buff[16];
- if (read(kg__tty, buff, sizeof(buff)) < 0)
- die("couldn't read from terminal: %s", strerror(errno));
- }
-
- /* --- Fiddle with times --- *
- *
- * Read the time now. Turn it into 32 bits of useful information, and
- * find the difference between that and the previous time. Compare this
- * with the difference between the previous pair of keypresses.
- */
-
- {
- struct timeval tv;
- uint_32 n, nd;
-
- gettimeofday(&tv, 0);
- n = tv.tv_usec / fact + tv.tv_sec * fact;
- if (!ldiff) {
- ldiff = n - last;
- last = n;
- continue;
- }
- nd = n - last;
- orr = nd | ldiff;
- xor = nd ^ ldiff;
- D( printf("\nlast = %08lx, next = %08lx, ldiff = %08lx, nd = %08lx\n",
- (unsigned long)last, (unsigned long)n,
- (unsigned long)ldiff, (unsigned long)nd);
- printf("xor = %08lx\n", (unsigned long)xor); )
- ldiff = nd;
- last = n;
- }
-
- /* --- Find the useful bits in this value --- *
- *
- * Find the least significant set bit in @bowl@ and chop it off. Then
- * find the most significant set bit and chop that off two. The rest is
- * probably interesting.
- */
-
- {
- unsigned long i;
-
- if (!orr || !xor)
- continue; /* erk! */
-
- useful = 30;
-
- i = 0x80000000ul;
- if (xor & i) {
- while (i && (xor & i) != 0) {
- i >>= 1;
- useful--;
- }
- } else {
- while (i && (xor & i) == 0) {
- i >>= 1;
- useful--;
- }
- }
- xor &= ~-i;
-
- while ((orr & 1) == 0) {
- useful--;
- orr >>= 1;
- xor >>= 1;
- }
- xor >>= 1;
-
- if (useful < 1)
- continue;
- }
-
- /* --- Now add the bits in the mixing bowl to my stash --- *
- *
- * There are two cases:
- *
- * 1. I have more bits than will fit into the accumulator. Then I must
- * put as many bits into the accumulator as will fit, store the
- * accumulator, and remove the spent bits.
- *
- * 2. I have too few bits to fit in the accumulator. Then shift them
- * in and return.
- */
-
- while (sz && useful) {
-
- D( printf("got %i bits, need %i/%i: %8lx\n",
- useful, bits, sz, (unsigned long)xor); )
-
- if (useful >= bits) {
-
- D( printf("shifted acc = %08lx\n"
- " new bits = %08lx\n"
- " result = %08lx\n",
- (unsigned long)(a << bits),
- (unsigned long)(xor >> (useful - bits)),
- (unsigned long)((a << bits) | (xor >> (useful - bits)))); )
-
- a = (a << bits) | (xor >> (useful - bits));
-
- sz -= bits;
- wsz -= bits;
- useful -= bits;
-
- if (sz == 0) {
- a <<= wsz;
- bits = 32 - wsz;
- } else
- bits = 32;
-
- while (bits > 0) {
- D( printf("writing %02x\n", (a >> 24) & 0xffu); )
- *ui++ = (a >> 24) & 0xffu;
- a <<= 8;
- bits -= 8;
- }
- a = 0;
-
- bits = 32 < sz ? 32 : sz;
-
- } else {
-
- D( printf("shifted acc = %08lx\n"
- " new bits = %08lx\n"
- " result = %08lx\n",
- (unsigned long)(a << useful),
- (unsigned long)(xor),
- (unsigned long)((a << useful) | (xor))); )
- a = (a << useful) | xor;
- bits -= useful;
- sz -= useful;
- wsz -= useful;
- useful = 0;
- }
- }
- }
-
- fputs("\rDone! \n", kg__ttyfp);
- putc('\a', kg__ttyfp); fflush(kg__ttyfp);
- sleep(1);
-}
-
-/* --- @main@ --- *
- *
- * Arguments: @int argc@ = number of arguments
- * @char *argv[]@ = array of arguments
- *
- * Returns: Zero if it worked, nonzero if it didn't.
- *
- * Use: Generates random numbers from the keyboard.
- */
-
-int main(int argc, char *argv[])
-{
- unsigned char *uip;
- size_t sz = 128;
- size_t keybits = 0;
- unsigned f = 0;
- const char *file = 0;
- FILE *fp;
-
- enum {
- f_envNoise = 1,
- f_keyTimer = 2
- };
-
- /* --- Formats table --- */
-
- static struct {
- const char *name;
- void (*proc)(unsigned char *k, size_t bits, FILE *fp);
- } format[] = {
- { "tx", tx_putBits },
- { "hex", tx_putBits },
- { "binary", kgFmt__binary },
- { "base64", kgFmt__base64 },
- { 0, 0 }
- };
-
- void (*fmt)(unsigned char *, size_t, FILE *) = tx_putBits;
-
- /* --- Explain who I am --- */
-
- ego(argv[0]);
-
- f |= f_envNoise | f_keyTimer;
-
- /* --- Read arguments --- */
-
- for (;;) {
- static struct option opts[] = {
- { "help", 0, 0, 'h' },
- { "bits", gFlag_argReq, 0, 'b' },
- { "output", gFlag_argReq, 0, 'o' },
- { "format", gFlag_argReq, 0, 'f' },
- { "key-times", gFlag_negate|gFlag_argOpt, 0, 'k' },
- { "env-noise", gFlag_negate, 0, 'e' },
- { 0, 0, 0, 0 }
- };
-
- int i = mdwopt(argc, argv, "hb:o:f:k+::e+", opts, 0, 0, gFlag_negation);
-
- if (i < 0)
- break;
- switch (i) {
- case 'h':
- printf(""
-"Usage: %s [-h] [-|+ek] [-b BITS] [-o FILE] [-f FORMAT]\n"
-"\n"
-"Generates BITS (by default, 128) random bits. The resulting number is\n"
-"written to FILE, or standard output.\n\n"
-"Randomness is taken from key-timings and environmental noise, although\n"
-"you can disable either (or both) of these sources.\n\n"
-"Options provided are:\n\n"
-"-h, --help Display this help text\n"
-"-b, --bits=BITS\t Generate BITS random bits instead of 128\n"
-"-o, --output=FILE Write bits to FILE, not standard output\n"
-"-f, --format=FORMAT Write bits in FORMAT:\n"
-" tx, hex Hexadecimal\n"
-" binary Raw binary\n"
-" base64 Base64-encoded binary\n"
-"-e, --[no-]env-noise Do [not] read environmental noise\n"
-"-k, --[no-]key-times[=BITS] Do [not] read key timing information\n"
-" (only read BITS bits from key timings)\n",
- quis());
- exit(0);
- break;
- case 'b':
- sz = atoi(optarg);
- if (sz == 0)
- die("bad number of bits (illegible or zero)");
- if (sz % 8)
- die("can only generate a whole number of 8-bit bytes");
- break;
- case 'o':
- file = optarg;
- break;
- case 'f':
- fmt = 0;
- for (i = 0; format[i].name; i++) {
- const char *p = format[i].name, *q = optarg;
- for (;;) {
- if (*q == 0)
- break;
- if (*p != *q)
- break;
- p++, q++;
- }
- if (!*q) {
- if (fmt)
- die("ambiguous format name: `%s'", optarg);
- fmt = format[i].proc;
- }
- }
- if (!fmt)
- die("unknown format name: `%s'", optarg);
- break;
- case 'e':
- f |= f_envNoise;
- break;
- case 'e' | gFlag_negated:
- f &= ~f_envNoise;
- break;
- case 'k':
- f |= f_keyTimer;
- if (optarg) {
- keybits = atoi(optarg);
- if (keybits == 0)
- die("bad number of bits (illegible or zero)");
- if (keybits % 8)
- die("bad number of bits (must be multiple of 8)");
- }
- else
- keybits = 0;
- break;
- case 'k' | gFlag_negated:
- f &= ~f_keyTimer;
- break;
- case '?':
- exit(1);
- break;
- }
- }
-
- /* --- Check the sanity of this request --- */
-
- {
- size_t bits = 0;
-
- if (f & f_keyTimer) {
- if (!keybits)
- keybits = sz;
- bits += keybits;
- }
- if (f & f_envNoise)
- bits += 384; /* Estimate */
-
- if (bits == 0)
- die("no randomness sources given");
- if (bits < sz)
- moan("warning: randomness may not be sufficiently high");
- }
-
- if (optind < argc) {
- fprintf(stderr, "Usage: %s [-opts]\n", quis());
- exit(1);
- }
-
- /* --- Allocate memory --- */
-
- {
- size_t buff = sz / 8;
- if (f & f_keyTimer && keybits > sz)
- buff = keybits / 8;
- uip = xmalloc(buff);
- }
-
- rand_clear();
-
- /* --- Fetch randomness from key timings --- */
-
- if (f & f_keyTimer) {
-
- /* --- Open the terminal --- *
- *
- * I'd like to be able to @fprintf@ to the terminal, so use @fopen@.
- */
-
- if ((kg__ttyfp = fopen("/dev/tty", "r+")) == 0)
- die("couldn't open terminal: %s", strerror(errno));
- kg__tty = fileno(kg__ttyfp);
-
- /* --- Tidy up nicely if I die --- */
-
- signal(SIGINT, kg__signal);
- signal(SIGTERM, kg__signal);
- atexit(kg__crepair);
-
- /* --- Put the terminal into cbreak, read the key, and restore --- */
-
- kg__cbreak();
- kg__gen(uip, keybits);
- kg__crepair();
- rand_add(uip, keybits / 8);
- rand_churn();
- }
-
- /* --- Find some noise from the environment too --- */
-
- if (f & f_envNoise) {
- noise_acquire();
- rand_churn();
- }
-
- /* --- Now write the number and exit --- */
-
- rand_extract(uip, sz / 8);
- D( fputs("*** ", fp); tx_putBits(uip, sz, stdout); )
-
- /* --- Open the output file, if one is specified --- */
-
- if (file) {
- int fd;
-
- /* --- Open the file oddly --- *
- *
- * There's a good reason for this. I want to be able to @fprintf@ (for
- * the benefit of @tx_putWords@ mainly) but I also want to ensure that
- * only the user has read permissions for the file. So I'll use @open@
- * with an appropriate mode and then @fdopen@ the file descriptor to
- * get a stream. Yuk.
- */
-
- if ((fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, 0600)) < 0)
- die("couldn't open output file: %s", strerror(errno));
- if ((fp = fdopen(fd, "w")) == 0)
- die("couldn't attach stream to output file: %s", strerror(errno));
- } else
- fp = stdout;
-
- fmt(uip, sz, fp);
- if (file)
- fclose(fp);
- memset(uip, 0, sz / 8); /* Burn temporary buffer */
- rand_clear();
- return (0);
-}
-
-/*----- That's all, folks -------------------------------------------------*/
~mdw / become / blobdiff