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Format code with prettier (#3375)

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This commit is contained in:
acbin
2022-10-03 17:23:00 +08:00
committed by GitHub
parent 32b9b11ed5
commit e96f567bfc
464 changed files with 11483 additions and 6189 deletions
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14
src/main/java/com/thealgorithms/ciphers/a5/A5Cipher.java
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@ -4,21 +4,22 @@ import java.util.BitSet;
// https://en.wikipedia.org/wiki/A5/1
public class A5Cipher {
private final A5KeyStreamGenerator keyStreamGenerator;
private static final int KEY_STREAM_LENGTH = 228; // 28.5 bytes so we need to pad bytes or something
public A5Cipher( BitSet sessionKey, BitSet frameCounter ) {
public A5Cipher(BitSet sessionKey, BitSet frameCounter) {
keyStreamGenerator = new A5KeyStreamGenerator();
keyStreamGenerator.initialize( sessionKey, frameCounter );
keyStreamGenerator.initialize(sessionKey, frameCounter);
}
public BitSet encrypt( BitSet plainTextBits ) {
public BitSet encrypt(BitSet plainTextBits) {
// create a copy
var result = new BitSet( KEY_STREAM_LENGTH );
result.xor( plainTextBits );
var result = new BitSet(KEY_STREAM_LENGTH);
result.xor(plainTextBits);
var key = keyStreamGenerator.getNextKeyStream();
result.xor( key );
result.xor(key);
return result;
}
@ -26,5 +27,4 @@ public class A5Cipher {
public void resetCounter() {
keyStreamGenerator.reInitialize();
}
}

36
src/main/java/com/thealgorithms/ciphers/a5/A5KeyStreamGenerator.java
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@ -4,6 +4,7 @@ import java.util.BitSet;
// TODO: raise exceptions for improper use
public class A5KeyStreamGenerator extends CompositeLFSR {
private BitSet initialFrameCounter;
private BitSet frameCounter;
private BitSet sessionKey;
@ -11,32 +12,35 @@ public class A5KeyStreamGenerator extends CompositeLFSR {
private static final int KEY_STREAM_LENGTH = 228; // 28.5 bytes so we need to pad bytes or something
@Override
public void initialize( BitSet sessionKey, BitSet frameCounter ) {
public void initialize(BitSet sessionKey, BitSet frameCounter) {
this.sessionKey = sessionKey;
this.frameCounter = (BitSet) frameCounter.clone();
this.initialFrameCounter = (BitSet) frameCounter.clone();
registers.clear();
LFSR lfsr1 = new LFSR( 19, 8, new int[]{ 13, 16, 17, 18 } );
LFSR lfsr2 = new LFSR( 22, 10, new int[]{ 20, 21 } );
LFSR lfsr3 = new LFSR( 23, 10, new int[]{ 7, 20, 21, 22 } );
registers.add( lfsr1 );
registers.add( lfsr2 );
registers.add( lfsr3 );
registers.forEach( lfsr -> lfsr.initialize( sessionKey, frameCounter ) );
LFSR lfsr1 = new LFSR(19, 8, new int[] { 13, 16, 17, 18 });
LFSR lfsr2 = new LFSR(22, 10, new int[] { 20, 21 });
LFSR lfsr3 = new LFSR(23, 10, new int[] { 7, 20, 21, 22 });
registers.add(lfsr1);
registers.add(lfsr2);
registers.add(lfsr3);
registers.forEach(lfsr -> lfsr.initialize(sessionKey, frameCounter));
}
public void reInitialize() {
this.initialize( sessionKey, initialFrameCounter );
this.initialize(sessionKey, initialFrameCounter);
}
public BitSet getNextKeyStream() {
for ( int cycle = 1; cycle <= INITIAL_CLOCKING_CYCLES; ++cycle )
this.clock();
for (
int cycle = 1;
cycle <= INITIAL_CLOCKING_CYCLES;
++cycle
) this.clock();
BitSet result = new BitSet( KEY_STREAM_LENGTH );
for ( int cycle = 1; cycle <= KEY_STREAM_LENGTH; ++cycle ) {
BitSet result = new BitSet(KEY_STREAM_LENGTH);
for (int cycle = 1; cycle <= KEY_STREAM_LENGTH; ++cycle) {
boolean outputBit = this.clock();
result.set( cycle - 1, outputBit );
result.set(cycle - 1, outputBit);
}
reInitializeRegisters();
@ -45,10 +49,10 @@ public class A5KeyStreamGenerator extends CompositeLFSR {
private void reInitializeRegisters() {
incrementFrameCounter();
registers.forEach( lfsr -> lfsr.initialize( sessionKey, frameCounter ) );
registers.forEach(lfsr -> lfsr.initialize(sessionKey, frameCounter));
}
private void incrementFrameCounter() {
Utils.increment( frameCounter, FRAME_COUNTER_LENGTH );
Utils.increment(frameCounter, FRAME_COUNTER_LENGTH);
}
}

19
src/main/java/com/thealgorithms/ciphers/a5/CompositeLFSR.java
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@ -6,6 +6,7 @@ import java.util.Map;
import java.util.TreeMap;
public abstract class CompositeLFSR implements BaseLFSR {
protected final List<LFSR> registers = new ArrayList<>();
/**
@ -16,20 +17,24 @@ public abstract class CompositeLFSR implements BaseLFSR {
public boolean clock() {
boolean majorityBit = getMajorityBit();
boolean result = false;
for ( var register : registers ) {
for (var register : registers) {
result ^= register.getLastBit();
if ( register.getClockBit() == majorityBit )
register.clock();
if (register.getClockBit() == majorityBit) register.clock();
}
return result;
}
private boolean getMajorityBit() {
Map<Boolean, Integer> bitCount = new TreeMap<>();
bitCount.put( false, 0 );
bitCount.put( true, 0 );
bitCount.put(false, 0);
bitCount.put(true, 0);
registers.forEach( lfsr -> bitCount.put( lfsr.getClockBit(), bitCount.get( lfsr.getClockBit() ) + 1 ) );
return bitCount.get( false ) <= bitCount.get( true );
registers.forEach(lfsr ->
bitCount.put(
lfsr.getClockBit(),
bitCount.get(lfsr.getClockBit()) + 1
)
);
return bitCount.get(false) <= bitCount.get(true);
}
}

45
src/main/java/com/thealgorithms/ciphers/a5/LFSR.java
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@ -3,71 +3,72 @@ package com.thealgorithms.ciphers.a5;
import java.util.BitSet;
public class LFSR implements BaseLFSR {
private final BitSet register;
private final int length;
private final int clockBitIndex;
private final int[] tappingBitsIndices;
public LFSR( int length, int clockBitIndex, int[] tappingBitsIndices ) {
public LFSR(int length, int clockBitIndex, int[] tappingBitsIndices) {
this.length = length;
this.clockBitIndex = clockBitIndex;
this.tappingBitsIndices = tappingBitsIndices;
register = new BitSet( length );
register = new BitSet(length);
}
@Override
public void initialize( BitSet sessionKey, BitSet frameCounter ) {
public void initialize(BitSet sessionKey, BitSet frameCounter) {
register.clear();
clock( sessionKey, SESSION_KEY_LENGTH );
clock( frameCounter, FRAME_COUNTER_LENGTH );
clock(sessionKey, SESSION_KEY_LENGTH);
clock(frameCounter, FRAME_COUNTER_LENGTH);
}
private void clock( BitSet key, int keyLength ) {
private void clock(BitSet key, int keyLength) {
// We start from reverse because LFSR 0 index is the left most bit
// while key 0 index is right most bit, so we reverse it
for ( int i = keyLength - 1; i >= 0; --i ) {
var newBit = key.get( i ) ^ xorTappingBits();
pushBit( newBit );
for (int i = keyLength - 1; i >= 0; --i) {
var newBit = key.get(i) ^ xorTappingBits();
pushBit(newBit);
}
}
@Override
public boolean clock() {
return pushBit( xorTappingBits() );
return pushBit(xorTappingBits());
}
public boolean getClockBit() {
return register.get( clockBitIndex );
return register.get(clockBitIndex);
}
public boolean get( int bitIndex ) {
return register.get( bitIndex );
public boolean get(int bitIndex) {
return register.get(bitIndex);
}
public boolean getLastBit() {
return register.get( length - 1 );
return register.get(length - 1);
}
private boolean xorTappingBits() {
boolean result = false;
for ( int i : tappingBitsIndices ) {
result ^= register.get( i );
for (int i : tappingBitsIndices) {
result ^= register.get(i);
}
return result;
}
private boolean pushBit( boolean bit ) {
private boolean pushBit(boolean bit) {
boolean discardedBit = rightShift();
register.set( 0, bit );
register.set(0, bit);
return discardedBit;
}
private boolean rightShift() {
boolean discardedBit = get( length - 1 );
for ( int i = length - 1; i > 0; --i ) {
register.set( i, get( i - 1 ) );
boolean discardedBit = get(length - 1);
for (int i = length - 1; i > 0; --i) {
register.set(i, get(i - 1));
}
register.set( 0, false );
register.set(0, false);
return discardedBit;
}

11
src/main/java/com/thealgorithms/ciphers/a5/Utils.java
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@ -7,15 +7,16 @@ package com.thealgorithms.ciphers.a5;
import java.util.BitSet;
public class Utils {
public static boolean increment( BitSet bits, int size ) {
public static boolean increment(BitSet bits, int size) {
int i = size - 1;
while ( i >= 0 && bits.get( i ) ) {
bits.set( i--, false );/*from w w w . j a v a 2s .c o m*/
while (i >= 0 && bits.get(i)) {
bits.set(i--, false);/*from w w w . j a v a 2s .c o m*/
}
if ( i < 0 ) {
if (i < 0) {
return false;
}
bits.set( i, true );
bits.set(i, true);
return true;
}
}