From: Gabor Juhos Date: Wed, 24 Jun 2009 16:35:38 +0000 (+0000) Subject: firmware-utils: add a file {en,de}cryption tool, based on the PC1 encryption algrithm X-Git-Url: http://git.cdn.openwrt.org/?a=commitdiff_plain;h=cb32efbc0e37d42c144aa3176de8a3cc5ae293ec;p=project%2Ffirmware-utils.git firmware-utils: add a file {en,de}cryption tool, based on the PC1 encryption algrithm SVN-Revision: 16550 --- diff --git a/Makefile b/Makefile index 96b4b59..6917bd8 100644 --- a/Makefile +++ b/Makefile @@ -49,6 +49,7 @@ define Host/Compile $(call cc,nand_ecc) $(call cc2,mkplanexfw sha1) $(call cc2,mktplinkfw md5) + $(call cc,pc1crypt) endef define Host/Install diff --git a/src/pc1crypt.c b/src/pc1crypt.c new file mode 100644 index 0000000..9c2eb83 --- /dev/null +++ b/src/pc1crypt.c @@ -0,0 +1,361 @@ +/* + * Copyright (C) 2009 Gabor Juhos + * + * 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 +#include +#include +#include +#include /* for unlink() */ +#include +#include /* for getopt() */ +#include +#include +#include + +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 read input from the file \n" +" -o write output to the 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; +} +