[proxmark3-svn] / client / loclass / cipherutils.c

/*****************************************************************************
 * WARNING
 *
 * THIS CODE IS CREATED FOR EXPERIMENTATION AND EDUCATIONAL USE ONLY. 
 * 
 * USAGE OF THIS CODE IN OTHER WAYS MAY INFRINGE UPON THE INTELLECTUAL 
 * PROPERTY OF OTHER PARTIES, SUCH AS INSIDE SECURE AND HID GLOBAL, 
 * AND MAY EXPOSE YOU TO AN INFRINGEMENT ACTION FROM THOSE PARTIES. 
 * 
 * THIS CODE SHOULD NEVER BE USED TO INFRINGE PATENTS OR INTELLECTUAL PROPERTY RIGHTS. 
 *
 *****************************************************************************
 *
 * This file is part of loclass. 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 <http://www.gnu.org/licenses/>.
 ****************************************************************************/

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include "fileutils.h"
#include "cipherutils.h"
/**
 *
 * @brief Return and remove the first bit (x0) in the stream : <x0 x1 x2 x3 ... xn >
 * @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: <x0 x1 x2 ... xn>
 * @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);
	free(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;
}
Commit	Line	Data
f38a1528	1	/*****************************************************************************
2ae8a312	2	* WARNING
	3	*
	4	* THIS CODE IS CREATED FOR EXPERIMENTATION AND EDUCATIONAL USE ONLY.
	5	*
	6	* USAGE OF THIS CODE IN OTHER WAYS MAY INFRINGE UPON THE INTELLECTUAL
	7	* PROPERTY OF OTHER PARTIES, SUCH AS INSIDE SECURE AND HID GLOBAL,
	8	* AND MAY EXPOSE YOU TO AN INFRINGEMENT ACTION FROM THOSE PARTIES.
	9	*
	10	* THIS CODE SHOULD NEVER BE USED TO INFRINGE PATENTS OR INTELLECTUAL PROPERTY RIGHTS.
	11	*
	12	*****************************************************************************
	13	*
	14	* This file is part of loclass. It is a reconstructon of the cipher engine
f38a1528	15	* used in iClass, and RFID techology.
	16	*
	17	* The implementation is based on the work performed by
	18	* Flavio D. Garcia, Gerhard de Koning Gans, Roel Verdult and
	19	* Milosch Meriac in the paper "Dismantling IClass".
	20	*
	21	* Copyright (C) 2014 Martin Holst Swende
	22	*
	23	* This is free software: you can redistribute it and/or modify
	24	* it under the terms of the GNU General Public License version 2 as published
	25	* by the Free Software Foundation.
	26	*
	27	* This file is distributed in the hope that it will be useful,
	28	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	29	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	30	* GNU General Public License for more details.
	31	*
	32	* You should have received a copy of the GNU General Public License
d3a22c7d	33	* along with IClassCipher. If not, see <http://www.gnu.org/licenses/>.
f38a1528	34	****************************************************************************/
	35
	36	#include <stdint.h>
	37	#include <stdio.h>
	38	#include <string.h>
	39	#include "fileutils.h"
	40	#include "cipherutils.h"
	41	/**
	42	*
	43	* @brief Return and remove the first bit (x0) in the stream : <x0 x1 x2 x3 ... xn >
	44	* @param stream
	45	* @return
	46	*/
	47	bool headBit( BitstreamIn *stream)
	48	{
	49	int bytepos = stream->position >> 3; // divide by 8
	50	int bitpos = (stream->position++) & 7; // mask out 00000111
	51	return (*(stream->buffer + bytepos) >> (7-bitpos)) & 1;
	52	}
	53	/**
	54	* @brief Return and remove the last bit (xn) in the stream: <x0 x1 x2 ... xn>
	55	* @param stream
	56	* @return
	57	*/
	58	bool tailBit( BitstreamIn *stream)
	59	{
	60	int bitpos = stream->numbits -1 - (stream->position++);
	61
	62	int bytepos= bitpos >> 3;
	63	bitpos &= 7;
	64	return (*(stream->buffer + bytepos) >> (7-bitpos)) & 1;
	65	}
	66	/**
	67	* @brief Pushes bit onto the stream
	68	* @param stream
	69	* @param bit
	70	*/
	71	void pushBit( BitstreamOut* stream, bool bit)
	72	{
	73	int bytepos = stream->position >> 3; // divide by 8
	74	int bitpos = stream->position & 7;
	75	*(stream->buffer+bytepos) \|= (bit & 1) << (7 - bitpos);
	76	stream->position++;
	77	stream->numbits++;
	78	}
	79
	80	/**
	81	* @brief Pushes the lower six bits onto the stream
	82	* as b0 b1 b2 b3 b4 b5 b6
	83	* @param stream
	84	* @param bits
	85	*/
	86	void push6bits( BitstreamOut* stream, uint8_t bits)
	87	{
	88	pushBit(stream, bits & 0x20);
	89	pushBit(stream, bits & 0x10);
	90	pushBit(stream, bits & 0x08);
	91	pushBit(stream, bits & 0x04);
	92	pushBit(stream, bits & 0x02);
	93	pushBit(stream, bits & 0x01);
	94	}
	95
	96	/**
	97	* @brief bitsLeft
98	* @param stream
99	* @return number of bits left in stream
100	*/
101	int bitsLeft( BitstreamIn *stream)
102	{
103	return stream->numbits - stream->position;
104	}
105	/**
106	* @brief numBits
107	* @param stream
108	* @return Number of bits stored in stream
109	*/
110	int numBits(BitstreamOut *stream)
111	{
112	return stream->numbits;
113	}
114
115	void x_num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
116	{
117	while (len--) {
118	dest[len] = (uint8_t) n;
119	n >>= 8;
120	}
121	}
122
123	uint64_t x_bytes_to_num(uint8_t* src, size_t len)
124	{
125	uint64_t num = 0;
126	while (len--)
127	{
128	num = (num << 8) \| (*src);
129	src++;
130	}
131	return num;
132	}
133	uint8_t reversebytes(uint8_t b) {
134	b = (b & 0xF0) >> 4 \| (b & 0x0F) << 4;
135	b = (b & 0xCC) >> 2 \| (b & 0x33) << 2;
136	b = (b & 0xAA) >> 1 \| (b & 0x55) << 1;
137	return b;
138	}
139	void reverse_arraybytes(uint8_t* arr, size_t len)
140	{
141	uint8_t i;
142	for( i =0; i< len ; i++)
143	{
144	arr[i] = reversebytes(arr[i]);
145	}
146	}
147	void reverse_arraycopy(uint8_t* arr, uint8_t* dest, size_t len)
148	{
149	uint8_t i;
150	for( i =0; i< len ; i++)
151	{
152	dest[i] = reversebytes(arr[i]);
153	}
154	}
155
156	void printarr(char * name, uint8_t* arr, int len)
157	{
158	int cx;
159	size_t outsize = 40+strlen(name)+len*5;
160	char* output = malloc(outsize);
161	memset(output, 0,outsize);
162
163	int i ;
164	cx = snprintf(output,outsize, "uint8_t %s[] = {", name);
165	for(i =0 ; i< len ; i++)
166	{
167	cx += snprintf(output+cx,outsize-cx,"0x%02x,",*(arr+i));//5 bytes per byte
168	}
169	cx += snprintf(output+cx,outsize-cx,"};");
170	prnlog(output);
171	}
172
173	void printvar(char * name, uint8_t* arr, int len)
174	{
175	int cx;
176	size_t outsize = 40+strlen(name)+len*2;
177	char* output = malloc(outsize);
178	memset(output, 0,outsize);
179
180	int i ;
181	cx = snprintf(output,outsize,"%s = ", name);
182	for(i =0 ; i< len ; i++)
183	{
184	cx += snprintf(output+cx,outsize-cx,"%02x",*(arr+i));//2 bytes per byte
185	}
186
187	prnlog(output);
188	}
189
190	void printarr_human_readable(char * title, uint8_t* arr, int len)
191	{
192	int cx;
193	size_t outsize = 100+strlen(title)+len*4;
194	char* output = malloc(outsize);
195	memset(output, 0,outsize);
196
197
198	int i;
199	cx = snprintf(output,outsize, "\n\t%s\n", title);
200	for(i =0 ; i< len ; i++)
201	{
202	if(i % 16 == 0)
203	cx += snprintf(output+cx,outsize-cx,"\n%02x\| ", i );
204	cx += snprintf(output+cx,outsize-cx, "%02x ",*(arr+i));
205	}
206	prnlog(output);
6ff6ade2	207	free(output);
f38a1528	208	}
	209
	210	//-----------------------------
	211	// Code for testing below
	212	//-----------------------------
	213
	214
	215	int testBitStream()
	216	{
	217	uint8_t input [] = {0xDE,0xAD,0xBE,0xEF,0xDE,0xAD,0xBE,0xEF};
	218	uint8_t output [] = {0,0,0,0,0,0,0,0};
	219	BitstreamIn in = { input, sizeof(input) * 8,0};
	220	BitstreamOut out ={ output, 0,0}
	221	;
	222	while(bitsLeft(&in) > 0)
	223	{
	224	pushBit(&out, headBit(&in));
	225	//printf("Bits left: %d\n", bitsLeft(&in));
	226	//printf("Bits out: %d\n", numBits(&out));
	227	}
	228	if(memcmp(input, output, sizeof(input)) == 0)
	229	{
	230	prnlog(" Bitstream test 1 ok");
	231	}else
	232	{
	233	prnlog(" Bitstream test 1 failed");
	234	uint8_t i;
	235	for(i = 0 ; i < sizeof(input) ; i++)
	236	{
	237	prnlog(" IN %02x, OUT %02x", input[i], output[i]);
	238	}
	239	return 1;
	240	}
	241	return 0;
	242	}
	243
	244	int testReversedBitstream()
	245	{
	246	uint8_t input [] = {0xDE,0xAD,0xBE,0xEF,0xDE,0xAD,0xBE,0xEF};
	247	uint8_t reverse [] = {0,0,0,0,0,0,0,0};
	248	uint8_t output [] = {0,0,0,0,0,0,0,0};
	249	BitstreamIn in = { input, sizeof(input) * 8,0};
	250	BitstreamOut out ={ output, 0,0};
	251	BitstreamIn reversed_in ={ reverse, sizeof(input)*8,0};
	252	BitstreamOut reversed_out ={ reverse,0 ,0};
	253
	254	while(bitsLeft(&in) > 0)
	255	{
	256	pushBit(&reversed_out, tailBit(&in));
	257	}
	258	while(bitsLeft(&reversed_in) > 0)
	259	{
	260	pushBit(&out, tailBit(&reversed_in));
	261	}
	262	if(memcmp(input, output, sizeof(input)) == 0)
	263	{
	264	prnlog(" Bitstream test 2 ok");
	265	}else
	266	{
	267	prnlog(" Bitstream test 2 failed");
	268	uint8_t i;
	269	for(i = 0 ; i < sizeof(input) ; i++)
	270	{
	271	prnlog(" IN %02x, MIDDLE: %02x, OUT %02x", input[i],reverse[i], output[i]);
272	}
273	return 1;
274	}
275	return 0;
276	}
277
278
279	int testCipherUtils(void)
280	{
281	prnlog("[+] Testing some internals...");
282	int retval = 0;
283	retval \|= testBitStream();
284	retval \|= testReversedBitstream();
285	return retval;
286	}