X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/6c0f60ca7bcd7737b5d3867004f1cbdc9532720c..3ad48540d4d77f50cc62d16acb78f17019ef431d:/client/loclass/cipherutils.c
diff --git a/client/loclass/cipherutils.c b/client/loclass/cipherutils.c
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+/*****************************************************************************
+ * This file is part of iClassCipher. It is a reconstructon of the cipher engine
+ * used in iClass, and RFID techology.
+ *
+ * The implementation is based on the work performed by
+ * Flavio D. Garcia, Gerhard de Koning Gans, Roel Verdult and
+ * Milosch Meriac in the paper "Dismantling IClass".
+ *
+ * Copyright (C) 2014 Martin Holst Swende
+ *
+ * This 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 file 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 IClassCipher. If not, see .
+ ****************************************************************************/
+
+#include
+#include
+#include
+#include "fileutils.h"
+#include "cipherutils.h"
+/**
+ *
+ * @brief Return and remove the first bit (x0) in the stream :
+ * @param stream
+ * @return
+ */
+bool headBit( BitstreamIn *stream)
+{
+ int bytepos = stream->position >> 3; // divide by 8
+ int bitpos = (stream->position++) & 7; // mask out 00000111
+ return (*(stream->buffer + bytepos) >> (7-bitpos)) & 1;
+}
+/**
+ * @brief Return and remove the last bit (xn) in the stream:
+ * @param stream
+ * @return
+ */
+bool tailBit( BitstreamIn *stream)
+{
+ int bitpos = stream->numbits -1 - (stream->position++);
+
+ int bytepos= bitpos >> 3;
+ bitpos &= 7;
+ return (*(stream->buffer + bytepos) >> (7-bitpos)) & 1;
+}
+/**
+ * @brief Pushes bit onto the stream
+ * @param stream
+ * @param bit
+ */
+void pushBit( BitstreamOut* stream, bool bit)
+{
+ int bytepos = stream->position >> 3; // divide by 8
+ int bitpos = stream->position & 7;
+ *(stream->buffer+bytepos) |= (bit & 1) << (7 - bitpos);
+ stream->position++;
+ stream->numbits++;
+}
+
+/**
+ * @brief Pushes the lower six bits onto the stream
+ * as b0 b1 b2 b3 b4 b5 b6
+ * @param stream
+ * @param bits
+ */
+void push6bits( BitstreamOut* stream, uint8_t bits)
+{
+ pushBit(stream, bits & 0x20);
+ pushBit(stream, bits & 0x10);
+ pushBit(stream, bits & 0x08);
+ pushBit(stream, bits & 0x04);
+ pushBit(stream, bits & 0x02);
+ pushBit(stream, bits & 0x01);
+}
+
+/**
+ * @brief bitsLeft
+ * @param stream
+ * @return number of bits left in stream
+ */
+int bitsLeft( BitstreamIn *stream)
+{
+ return stream->numbits - stream->position;
+}
+/**
+ * @brief numBits
+ * @param stream
+ * @return Number of bits stored in stream
+ */
+int numBits(BitstreamOut *stream)
+{
+ return stream->numbits;
+}
+
+void x_num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
+{
+ while (len--) {
+ dest[len] = (uint8_t) n;
+ n >>= 8;
+ }
+}
+
+uint64_t x_bytes_to_num(uint8_t* src, size_t len)
+{
+ uint64_t num = 0;
+ while (len--)
+ {
+ num = (num << 8) | (*src);
+ src++;
+ }
+ return num;
+}
+uint8_t reversebytes(uint8_t b) {
+ b = (b & 0xF0) >> 4 | (b & 0x0F) << 4;
+ b = (b & 0xCC) >> 2 | (b & 0x33) << 2;
+ b = (b & 0xAA) >> 1 | (b & 0x55) << 1;
+ return b;
+}
+void reverse_arraybytes(uint8_t* arr, size_t len)
+{
+ uint8_t i;
+ for( i =0; i< len ; i++)
+ {
+ arr[i] = reversebytes(arr[i]);
+ }
+}
+void reverse_arraycopy(uint8_t* arr, uint8_t* dest, size_t len)
+{
+ uint8_t i;
+ for( i =0; i< len ; i++)
+ {
+ dest[i] = reversebytes(arr[i]);
+ }
+}
+
+void printarr(char * name, uint8_t* arr, int len)
+{
+ int cx;
+ size_t outsize = 40+strlen(name)+len*5;
+ char* output = malloc(outsize);
+ memset(output, 0,outsize);
+
+ int i ;
+ cx = snprintf(output,outsize, "uint8_t %s[] = {", name);
+ for(i =0 ; i< len ; i++)
+ {
+ cx += snprintf(output+cx,outsize-cx,"0x%02x,",*(arr+i));//5 bytes per byte
+ }
+ cx += snprintf(output+cx,outsize-cx,"};");
+ prnlog(output);
+}
+
+void printvar(char * name, uint8_t* arr, int len)
+{
+ int cx;
+ size_t outsize = 40+strlen(name)+len*2;
+ char* output = malloc(outsize);
+ memset(output, 0,outsize);
+
+ int i ;
+ cx = snprintf(output,outsize,"%s = ", name);
+ for(i =0 ; i< len ; i++)
+ {
+ cx += snprintf(output+cx,outsize-cx,"%02x",*(arr+i));//2 bytes per byte
+ }
+
+ prnlog(output);
+}
+
+void printarr_human_readable(char * title, uint8_t* arr, int len)
+{
+ int cx;
+ size_t outsize = 100+strlen(title)+len*4;
+ char* output = malloc(outsize);
+ memset(output, 0,outsize);
+
+
+ int i;
+ cx = snprintf(output,outsize, "\n\t%s\n", title);
+ for(i =0 ; i< len ; i++)
+ {
+ if(i % 16 == 0)
+ cx += snprintf(output+cx,outsize-cx,"\n%02x| ", i );
+ cx += snprintf(output+cx,outsize-cx, "%02x ",*(arr+i));
+ }
+ prnlog(output);
+}
+
+//-----------------------------
+// Code for testing below
+//-----------------------------
+
+
+int testBitStream()
+{
+ uint8_t input [] = {0xDE,0xAD,0xBE,0xEF,0xDE,0xAD,0xBE,0xEF};
+ uint8_t output [] = {0,0,0,0,0,0,0,0};
+ BitstreamIn in = { input, sizeof(input) * 8,0};
+ BitstreamOut out ={ output, 0,0}
+ ;
+ while(bitsLeft(&in) > 0)
+ {
+ pushBit(&out, headBit(&in));
+ //printf("Bits left: %d\n", bitsLeft(&in));
+ //printf("Bits out: %d\n", numBits(&out));
+ }
+ if(memcmp(input, output, sizeof(input)) == 0)
+ {
+ prnlog(" Bitstream test 1 ok");
+ }else
+ {
+ prnlog(" Bitstream test 1 failed");
+ uint8_t i;
+ for(i = 0 ; i < sizeof(input) ; i++)
+ {
+ prnlog(" IN %02x, OUT %02x", input[i], output[i]);
+ }
+ return 1;
+ }
+ return 0;
+}
+
+int testReversedBitstream()
+{
+ uint8_t input [] = {0xDE,0xAD,0xBE,0xEF,0xDE,0xAD,0xBE,0xEF};
+ uint8_t reverse [] = {0,0,0,0,0,0,0,0};
+ uint8_t output [] = {0,0,0,0,0,0,0,0};
+ BitstreamIn in = { input, sizeof(input) * 8,0};
+ BitstreamOut out ={ output, 0,0};
+ BitstreamIn reversed_in ={ reverse, sizeof(input)*8,0};
+ BitstreamOut reversed_out ={ reverse,0 ,0};
+
+ while(bitsLeft(&in) > 0)
+ {
+ pushBit(&reversed_out, tailBit(&in));
+ }
+ while(bitsLeft(&reversed_in) > 0)
+ {
+ pushBit(&out, tailBit(&reversed_in));
+ }
+ if(memcmp(input, output, sizeof(input)) == 0)
+ {
+ prnlog(" Bitstream test 2 ok");
+ }else
+ {
+ prnlog(" Bitstream test 2 failed");
+ uint8_t i;
+ for(i = 0 ; i < sizeof(input) ; i++)
+ {
+ prnlog(" IN %02x, MIDDLE: %02x, OUT %02x", input[i],reverse[i], output[i]);
+ }
+ return 1;
+ }
+ return 0;
+}
+
+
+int testCipherUtils(void)
+{
+ prnlog("[+] Testing some internals...");
+ int retval = 0;
+ retval |= testBitStream();
+ retval |= testReversedBitstream();
+ return retval;
+}