+/*
+ * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This code was based on:
+ * PC1 Cipher Algorithm ( Pukall Cipher 1 )
+ * By Alexander PUKALL 1991
+ * free code no restriction to use
+ * please include the name of the Author in the final software
+ * the Key is 128 bits
+ * http://membres.lycos.fr/pc1/
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h> /* for unlink() */
+#include <libgen.h>
+#include <getopt.h> /* for getopt() */
+#include <stdarg.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+struct pc1_ctx {
+ unsigned short ax;
+ unsigned short bx;
+ unsigned short cx;
+ unsigned short dx;
+ unsigned short si;
+ unsigned short tmp;
+ unsigned short x1a2;
+ unsigned short x1a0[8];
+ unsigned short res;
+ unsigned short i;
+ unsigned short inter;
+ unsigned short cfc;
+ unsigned short cfd;
+ unsigned short compte;
+ unsigned char cle[17];
+ short c;
+};
+
+static void pc1_finish(struct pc1_ctx *pc1)
+{
+ /* erase all variables */
+ memset(pc1, 0, sizeof(struct pc1_ctx));
+}
+
+static void pc1_code(struct pc1_ctx *pc1)
+{
+ pc1->dx = pc1->x1a2 + pc1->i;
+ pc1->ax = pc1->x1a0[pc1->i];
+ pc1->cx = 0x015a;
+ pc1->bx = 0x4e35;
+
+ pc1->tmp = pc1->ax;
+ pc1->ax = pc1->si;
+ pc1->si = pc1->tmp;
+
+ pc1->tmp = pc1->ax;
+ pc1->ax = pc1->dx;
+ pc1->dx = pc1->tmp;
+
+ if (pc1->ax != 0) {
+ pc1->ax = pc1->ax * pc1->bx;
+ }
+
+ pc1->tmp = pc1->ax;
+ pc1->ax = pc1->cx;
+ pc1->cx = pc1->tmp;
+
+ if (pc1->ax != 0) {
+ pc1->ax = pc1->ax * pc1->si;
+ pc1->cx = pc1->ax + pc1->cx;
+ }
+
+ pc1->tmp = pc1->ax;
+ pc1->ax = pc1->si;
+ pc1->si = pc1->tmp;
+ pc1->ax = pc1->ax * pc1->bx;
+ pc1->dx = pc1->cx + pc1->dx;
+
+ pc1->ax = pc1->ax + 1;
+
+ pc1->x1a2 = pc1->dx;
+ pc1->x1a0[pc1->i] = pc1->ax;
+
+ pc1->res = pc1->ax ^ pc1->dx;
+ pc1->i = pc1->i + 1;
+}
+
+static void pc1_assemble(struct pc1_ctx *pc1)
+{
+ pc1->x1a0[0] = (pc1->cle[0] * 256) + pc1->cle[1];
+
+ pc1_code(pc1);
+ pc1->inter = pc1->res;
+
+ pc1->x1a0[1] = pc1->x1a0[0] ^ ((pc1->cle[2]*256) + pc1->cle[3]);
+ pc1_code(pc1);
+ pc1->inter = pc1->inter ^ pc1->res;
+
+ pc1->x1a0[2] = pc1->x1a0[1] ^ ((pc1->cle[4]*256) + pc1->cle[5]);
+ pc1_code(pc1);
+ pc1->inter = pc1->inter ^ pc1->res;
+
+ pc1->x1a0[3] = pc1->x1a0[2] ^ ((pc1->cle[6]*256) + pc1->cle[7]);
+ pc1_code(pc1);
+ pc1->inter = pc1->inter ^ pc1->res;
+
+ pc1->x1a0[4] = pc1->x1a0[3] ^ ((pc1->cle[8]*256) + pc1->cle[9]);
+ pc1_code(pc1);
+ pc1->inter = pc1->inter ^ pc1->res;
+
+ pc1->x1a0[5] = pc1->x1a0[4] ^ ((pc1->cle[10]*256) + pc1->cle[11]);
+ pc1_code(pc1);
+ pc1->inter = pc1->inter ^ pc1->res;
+
+ pc1->x1a0[6] = pc1->x1a0[5] ^ ((pc1->cle[12]*256) + pc1->cle[13]);
+ pc1_code(pc1);
+ pc1->inter = pc1->inter ^ pc1->res;
+
+ pc1->x1a0[7] = pc1->x1a0[6] ^ ((pc1->cle[14]*256) + pc1->cle[15]);
+ pc1_code(pc1);
+ pc1->inter = pc1->inter ^ pc1->res;
+
+ pc1->i = 0;
+}
+
+static unsigned char pc1_decrypt(struct pc1_ctx *pc1, short c)
+{
+ pc1_assemble(pc1);
+ pc1->cfc = pc1->inter >> 8;
+ pc1->cfd = pc1->inter & 255; /* cfc^cfd = random byte */
+
+ c = c ^ (pc1->cfc ^ pc1->cfd);
+ for (pc1->compte = 0; pc1->compte <= 15; pc1->compte++) {
+ /* we mix the plaintext byte with the key */
+ pc1->cle[pc1->compte] = pc1->cle[pc1->compte] ^ c;
+ }
+
+ return c;
+}
+
+static unsigned char pc1_encrypt(struct pc1_ctx *pc1, short c)
+{
+ pc1_assemble(pc1);
+ pc1->cfc = pc1->inter >> 8;
+ pc1->cfd = pc1->inter & 255; /* cfc^cfd = random byte */
+
+ for (pc1->compte = 0; pc1->compte <= 15; pc1->compte++) {
+ /* we mix the plaintext byte with the key */
+ pc1->cle[pc1->compte] = pc1->cle[pc1->compte] ^ c;
+ }
+ c = c ^ (pc1->cfc ^ pc1->cfd);
+
+ return c;
+}
+
+static void pc1_init(struct pc1_ctx *pc1)
+{
+ memset(pc1, 0, sizeof(struct pc1_ctx));
+
+ /* ('Remsaalps!123456') is the key used, you can change it */
+ strcpy(pc1->cle, "Remsaalps!123456");
+}
+
+static void pc1_decrypt_buf(struct pc1_ctx *pc1, unsigned char *buf,
+ unsigned len)
+{
+ unsigned i;
+
+ for (i = 0; i < len; i++)
+ buf[i] = pc1_decrypt(pc1, buf[i]);
+}
+
+static void pc1_encrypt_buf(struct pc1_ctx *pc1, unsigned char *buf,
+ unsigned len)
+{
+ unsigned i;
+
+ for (i = 0; i < len; i++)
+ buf[i] = pc1_encrypt(pc1, buf[i]);
+}
+
+/*
+ * Globals
+ */
+static char *ifname;
+static char *progname;
+static char *ofname;
+static int decrypt;
+
+/*
+ * Message macros
+ */
+#define ERR(fmt, ...) do { \
+ fflush(0); \
+ fprintf(stderr, "[%s] *** error: " fmt "\n", \
+ progname, ## __VA_ARGS__ ); \
+} while (0)
+
+#define ERRS(fmt, ...) do { \
+ int save = errno; \
+ fflush(0); \
+ fprintf(stderr, "[%s] *** error: " fmt "\n", \
+ progname, ## __VA_ARGS__, strerror(save)); \
+} while (0)
+
+void usage(int status)
+{
+ FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
+ struct board_info *board;
+
+ fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
+ fprintf(stream,
+"\n"
+"Options:\n"
+" -d decrypt instead of encrypt"
+" -i <file> read input from the file <file>\n"
+" -o <file> write output to the file <file>\n"
+" -h show this screen\n"
+ );
+
+ exit(status);
+}
+
+#define BUFSIZE (64 * 1024)
+
+int main(int argc, char *argv[])
+{
+ struct pc1_ctx pc1;
+ int res = EXIT_FAILURE;
+ int err;
+ struct stat st;
+ char *buf;
+ unsigned total;
+
+ FILE *outfile, *infile;
+
+ progname = basename(argv[0]);
+
+ while ( 1 ) {
+ int c;
+
+ c = getopt(argc, argv, "di:o:h");
+ if (c == -1)
+ break;
+
+ switch (c) {
+ case 'd':
+ decrypt = 1;
+ break;
+ case 'i':
+ ifname = optarg;
+ break;
+ case 'o':
+ ofname = optarg;
+ break;
+ case 'h':
+ usage(EXIT_SUCCESS);
+ break;
+ default:
+ usage(EXIT_FAILURE);
+ break;
+ }
+ }
+
+ if (ifname == NULL) {
+ ERR("no input file specified");
+ goto err;
+ }
+
+ if (ofname == NULL) {
+ ERR("no output file specified");
+ goto err;
+ }
+
+ err = stat(ifname, &st);
+ if (err){
+ ERRS("stat failed on %s", ifname);
+ goto err;
+ }
+
+ total = st.st_size;
+ buf = malloc(BUFSIZE);
+ if (!buf) {
+ ERR("no memory for buffer\n");
+ goto err;
+ }
+
+ infile = fopen(ifname, "r");
+ if (infile == NULL) {
+ ERRS("could not open \"%s\" for reading", ifname);
+ goto err_free;
+ }
+
+ outfile = fopen(ofname, "w");
+ if (outfile == NULL) {
+ ERRS("could not open \"%s\" for writing", ofname);
+ goto err_close_in;
+ }
+
+ pc1_init(&pc1);
+ while (total > 0) {
+ unsigned datalen;
+
+ if (total > BUFSIZE)
+ datalen = BUFSIZE;
+ else
+ datalen = total;
+
+ errno = 0;
+ fread(buf, datalen, 1, infile);
+ if (errno != 0) {
+ ERRS("unable to read from file %s", ifname);
+ goto err_close_out;
+ }
+
+ if (decrypt)
+ pc1_decrypt_buf(&pc1, buf, datalen);
+ else
+ pc1_encrypt_buf(&pc1, buf, datalen);
+
+ errno = 0;
+ fwrite(buf, datalen, 1, outfile);
+ if (errno) {
+ ERRS("unable to write to file %s", ofname);
+ goto err_close_out;
+ }
+
+ total -= datalen;
+ }
+ pc1_finish(&pc1);
+
+ res = EXIT_SUCCESS;
+
+ out_flush:
+ fflush(outfile);
+
+ err_close_out:
+ fclose(outfile);
+ if (res != EXIT_SUCCESS) {
+ unlink(ofname);
+ }
+
+ err_close_in:
+ fclose(infile);
+
+ err_free:
+ free(buf);
+
+ err:
+ return res;
+}
+
projects / openwrt.git / commitdiff