mirror of https://github.com/dirtbags/moth.git
137 lines
2.8 KiB
C
137 lines
2.8 KiB
C
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#include <sys/types.h>
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#include <time.h>
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#include <unistd.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <stddef.h>
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#include <ctype.h>
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#include "xxtea.h"
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#define itokenlen 3
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char const consonants[] = "bcdfghklmnprstvz";
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char const vowels[] = "aeiouy";
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#define bubblebabble_len(n) (6*(((n)/2)+1))
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/** Compute bubble babble for input buffer.
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*
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* The generated output will be of length 6*((inlen/2)+1), including the
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* trailing NULL.
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*
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* Test vectors:
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* `' (empty string) `xexax'
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* `1234567890' `xesef-disof-gytuf-katof-movif-baxux'
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* `Pineapple' `xigak-nyryk-humil-bosek-sonax'
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*/
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void
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bubblebabble(char *out, char const *in, const size_t inlen)
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{
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size_t pos = 0;
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int seed = 1;
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size_t i = 0;
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out[pos++] = 'x';
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while (1) {
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unsigned char c;
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if (i == inlen) {
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out[pos++] = vowels[seed % 6];
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out[pos++] = 'x';
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out[pos++] = vowels[seed / 6];
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break;
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}
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c = in[i++];
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out[pos++] = vowels[(((c >> 6) & 3) + seed) % 6];
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out[pos++] = consonants[(c >> 2) & 15];
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out[pos++] = vowels[((c & 3) + (seed / 6)) % 6];
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if (i == inlen) {
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break;
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}
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seed = ((seed * 5) + (c * 7) + in[i]) % 36;
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c = in[i++];
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out[pos++] = consonants[(c >> 4) & 15];
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out[pos++] = '-';
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out[pos++] = consonants[c & 15];
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}
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out[pos++] = 'x';
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out[pos] = '\0';
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}
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int
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main(int argc, char *argv[])
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{
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char service[50];
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char token[80];
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uint32_t key[4];
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size_t tokenlen;
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/* This ought to be unpredictable enough for a contest */
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srand((int)time(NULL) * (int)getpid());
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/* Read service name */
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{
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size_t len;
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int i;
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len = fread(service, 1, sizeof(service) - 1, stdin);
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for (i = 0; (i < len) && isalnum(service[i]); i += 1);
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service[i] = '\0';
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}
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/* Read in that service's key */
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{
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FILE *f = fopen(service, "r");
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size_t len;
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if (! f) {
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printf("Unregistered service");
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return 0;
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}
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len = fread(&key, sizeof(uint32_t), 4, f);
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fclose(f);
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if (4 != len) {
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printf("Key file screwed up");
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return 0;
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}
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}
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/* Create the token */
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{
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uint8_t crap[itokenlen];
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char digest[bubblebabble_len(itokenlen)];
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int i;
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/* Digest some random junk */
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for (i = 0; i < itokenlen; i += 1) {
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crap[i] = (uint8_t)random();
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}
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bubblebabble(digest, crap, itokenlen);
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/* Append digest to service name */
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tokenlen = (size_t)snprintf(token, sizeof(token),
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"%s:%s",
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service, digest);
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}
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/* Encrypt the token */
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/* Note that now tokenlen is in uint32_ts, not chars! */
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{
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tokenlen = (tokenlen + (tokenlen % 4)) / 4;
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tea_encode(key, (uint32_t *)token, tokenlen);
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}
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/* Send it back */
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fwrite(token, tokenlen, sizeof(uint32_t), stdout);
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return 0;
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}
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