attack.c File Reference

Implementation of A52 attack. More...

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include <time.h>
#include "utils.h"
#include "attack.h"
#include "code.h"
#include "keygen.h"
#include "matrices_generation.h"
#include "keysetup_reverse.h"

Functions
void	attack_redispatchLFSRdata (const byte LFSRState[REGS_TOTAL_VARS-1], byte R1[R1_BITS], byte R2[R2_BITS], byte R3[R3_BITS])
	Translates a compact LFSR representation (only including variables) into separate registers (adding initial "1" constants)
int	attack_checkDoubleVars (const byte LFSRState[REGS_TOTAL_VARS-1])
	Checks that all double variables values are consistent with single variables ones.
void	freeRAM ()
	Frees the RAM used to store resolution matrices.
int	initializeRAM (const char *filename)
	Initializes the RAM storage of resolution matrices from a given binary file.
int	attack_decipherSecretKey (cipherTextArgs *ctArgs, int lowindex, int highindex, int *keyFound, byte secretKey[SECRETKEY_BITS])
	Thread attack method.
void *	attack_launchAttack (void *data)
	Thread initializer.
int	attack (cipherTextArgs *ctArgs, byte secretKey[SECRETKEY_BITS])
	Performs the attack on a given problem, then writes back the solution.
int	attack_test ()
	Autotests the attack on a verified set of problem/solution.
Variables
unsigned int **	ALLMATRICES
	RAM Storage for Resolution Matrices.

---

Detailed Description

Implementation of A52 attack.

Author:

Nicolas Paglieri & Olivier Benjamin

Version:

File Revision #27

Date:

01/12/2011

---

Function Documentation

int attack	(	cipherTextArgs *	ctArgs,
		byte	secretKey[SECRETKEY_BITS]
	)

Performs the attack on a given problem, then writes back the solution.

Parameters:

[in]	ctArgs	Problem to be solved
[out]	secretKey	Deciphered secret key if the attack succeeded, all zeros otherwise

Returns:

0 if the attack is successfull, non-zero otherwise

References ALLMATRICES, attack_launchAttack(), threadArgs::ctArgs, DEBUG, DUMP_CHAR_VECTOR, threadArgs::highindex, threadArgs::keyFound, threadArgs::lowindex, PROCESSING_THREADS, and THREAD_CHUNKSIZE.

Referenced by attack_test(), and main().

int attack_checkDoubleVars

(

const byte

LFSRState[REGS_TOTAL_VARS-1]

)

Checks that all double variables values are consistent with single variables ones.

Parameters:

[in]

LFSRState

Compact LFSR representation

Returns:

0 if the state is consistent, non-zero otherwise

References R1_SIMPLE_VARS, R2_SIMPLE_VARS, R3_SIMPLE_VARS, and REGS_SIMPLE_VARS.

Referenced by attack_decipherSecretKey().

int attack_decipherSecretKey	(	cipherTextArgs *	ctArgs,
		int	lowindex,
		int	highindex,
		int *	keyFound,
		byte	secretKey[SECRETKEY_BITS]
	)

Thread attack method.

Parameters:

[in]	ctArgs	Problem to solve
[in]	lowindex	Index to start the search form (inclusive)
[in]	highindex	Last index to be analyzed (exclusive)
[in]	keyFound	Solution found flag
[out]	secretKey	Storage for a potential solution

Returns:

0 if the attack is thread-locally successful, non-zero otherwise

References ALLMATRICES, attack_checkDoubleVars(), attack_redispatchLFSRdata(), BINPRODUCT_MATRIX_VECTOR, cipherTextArgs::cipherText1, cipherTextArgs::cipherText2, cipherTextArgs::cipherText3, CODEWORD_LENGTH, cipherTextArgs::frameId, getR4fromIndex(), NEEDED_ENCRYPTED_MESSAGES, processFullEncodingGMatrix(), processFullEncodingHMatrix(), PROGRESSBAR, R1, R1_BITS, R2, R2_BITS, R3, R3_BITS, R4, R4_BITS, REGS_TOTAL_VARS, RESOLUTION_MATRIX_INT_WIDTH, reverseKeysetup(), SOURCEWORD_LENGTH, SYNDROME_EMPTY_EQUATIONS, SYNDROME_LENGTH, and THREAD_CHUNKSIZE.

Referenced by attack_launchAttack().

void * attack_launchAttack

(

void *

data

)

Thread initializer.

Parameters:

[in]

data

Pointer to the thread's arguments

Returns:

NULL

References attack_decipherSecretKey(), threadArgs::ctArgs, threadArgs::highindex, threadArgs::keyFound, threadArgs::lowindex, and threadArgs::secretKey.

Referenced by attack().

void attack_redispatchLFSRdata	(	const byte	LFSRState[REGS_TOTAL_VARS-1],
		byte	R1[R1_BITS],
		byte	R2[R2_BITS],
		byte	R3[R3_BITS]
	)

Translates a compact LFSR representation (only including variables) into separate registers (adding initial "1" constants)

Parameters:

[in]	LFSRState	Compact LFSR representation
[out]	R1	First LFSR
[out]	R2	Second LFSR
[out]	R3	Third LFSR

References R1, R1_INITIAL_CONST_POS, R1_SIMPLE_VARS, R2, R2_INITIAL_CONST_POS, R2_SIMPLE_VARS, R3, R3_INITIAL_CONST_POS, and R3_SIMPLE_VARS.

Referenced by attack_decipherSecretKey().

int attack_test

(

)

Autotests the attack on a verified set of problem/solution.

Returns:

0 if the test is successfull, non-zero otherwise

References attack(), BINPRODUCT_VECTOR_MATRIX, cipherTextArgs::cipherText1, cipherTextArgs::cipherText2, cipherTextArgs::cipherText3, CODEWORD_LENGTH, DEBUG, DEBUG_LF, DUMP_CHAR_VECTOR, cipherTextArgs::frameId, FRAMEID_BITS, freeRAM(), getKeystream(), initializeRAM(), keysetup(), NEEDED_ENCRYPTED_MESSAGES, processFullEncodingGMatrix(), SECRETKEY_BITS, SOURCEWORD_LENGTH, and XOR_CHARARRAYS.

Referenced by main().

int initializeRAM

(

const char *

filename

)

Initializes the RAM storage of resolution matrices from a given binary file.

Parameters:

[in]

filename

Path of the file containing resolution matrices

Returns:

0 if the initialization is successfull, non-zero otherwise

References ALLMATRICES, BUFFER_SIZE, DEBUG, freeRAM(), NEEDED_ENCRYPTED_MESSAGES, RESOLUTION_MATRIX_INT_WIDTH, SYNDROME_LENGTH, and TOTAL_MATRICES.

Referenced by attack_test(), and main().