MD4: Difference between revisions

Content added Content deleted
m (Minor coding improvement.)
m (Improved coding.)
Line 782: Line 782:
String text = "Rosetta Code";
String text = "Rosetta Code";
MD4 md4 = new MD4();
MD4 md4 = new MD4();
md4.engineUpdate(text.getBytes(), 0, text.length());
byte[] result = md4.engineDigest(text);
byte[] result = md4.engineDigest();
StringBuilder stringBuilder = new StringBuilder();
StringBuilder stringBuilder = new StringBuilder();
for ( byte bb : result ) {
for ( byte bb : result ) {
Line 793: Line 792:
}
}
}
private static class MD4 {
public MD4() {
final class MD4 {
engineReset();
public MD4() {
}
engineReset();
}
public void engineReset() {
context[0] = 0x67452301;
context[1] = 0xefcdab89;
context[2] = 0x98badcfe;
context[3] = 0x10325476;
count = 0L;
Arrays.fill(buffer, (byte) 0);
}
public void engineUpdate(byte[] aMessageBytes, int aOffset, int aMessageLength) {
if ( aOffset < 0 || aMessageLength < 0 || (long) aOffset + aMessageLength > (long) aMessageBytes.length ) {
throw new ArrayIndexOutOfBoundsException("Incorrect arguments for method engineUpdate");
}
int bufferIndex = (int) ( count % BLOCK_LENGTH );
count += aMessageLength;
final int partialLength = BLOCK_LENGTH - bufferIndex;
int i = 0;
if ( aMessageLength >= partialLength ) {
System.arraycopy(aMessageBytes, aOffset, buffer, bufferIndex, partialLength);
transform(buffer, 0);
i = partialLength;
while ( i + BLOCK_LENGTH - 1 < aMessageLength ) {
transform(aMessageBytes, aOffset + i);
i += BLOCK_LENGTH;
}
bufferIndex = 0;
}
if ( i < aMessageLength ) {
System.arraycopy(aMessageBytes, aOffset + i, buffer, bufferIndex, aMessageLength - i);
}
}


public byte[] engineDigest() {
public byte[] engineDigest(String aText) {
engineUpdate(aText.getBytes(), 0, aText.length());
final int bufferIndex = (int) ( count % BLOCK_LENGTH );
final int paddingLength = ( bufferIndex < 56 ) ? 56 - bufferIndex : 120 - bufferIndex;

byte[] tail = new byte[paddingLength + 8];
tail[0] = (byte) 0x80;

for ( int i = 0; i < 8; i++ ) {
tail[paddingLength + i] = (byte) ( ( count * 8 ) >>> ( 8 * i ) );
}

engineUpdate(tail, 0, tail.length);

byte[] result = new byte[16];
for ( int i = 0; i < 4; i++ ) {
for ( int j = 0; j < 4; j++ ) {
result[i * 4 + j] = (byte) ( context[i] >>> ( 8 * j ) );
}
}

engineReset();
return result;
}
final int bufferIndex = (int) ( count % BLOCK_LENGTH );
private void transform (byte[] aBlock, int aOffset) {
for ( int i = 0; i < 16; i++ ) {
final int paddingLength = ( bufferIndex < 56 ) ? 56 - bufferIndex : 120 - bufferIndex;
extra[i] = ( ( (int) aBlock[aOffset++] & 0xff ) ) |
( ( (int) aBlock[aOffset++] & 0xff ) << 8 ) |
( ( (int) aBlock[aOffset++] & 0xff ) << 16 ) |
( ( (int) aBlock[aOffset++] & 0xff ) << 24 );
}


int a = context[0];
byte[] tail = new byte[paddingLength + 8];
int b = context[1];
tail[0] = (byte) 0x80;
int c = context[2];
int d = context[3];
for ( int i = 0; i < 8; i++ ) {
tail[paddingLength + i] = (byte) ( ( count * 8 ) >>> ( 8 * i ) );
}
for ( int i : List.of( 0, 4, 8, 12 ) ) {
a = ff(a, b, c, d, extra[i + 0], 3);
d = ff(d, a, b, c, extra[i + 1], 7);
engineUpdate(tail, 0, tail.length);
c = ff(c, d, a, b, extra[i + 2], 11);
b = ff(b, c, d, a, extra[i + 3], 19);
}
for ( int i : List.of( 0, 1, 2, 3 ) ) {
a = gg(a, b, c, d, extra[i + 0], 3);
d = gg(d, a, b, c, extra[i + 4], 5);
c = gg(c, d, a, b, extra[i + 8], 9);
b = gg(b, c, d, a, extra[i + 12], 13);
}
for ( int i : List.of( 0, 2, 1, 3 ) ) {
a = hh(a, b, c, d, extra[i + 0], 3);
d = hh(d, a, b, c, extra[i + 8], 9);
c = hh(c, d, a, b, extra[i + 4], 11);
b = hh(b, c, d, a, extra[i + 12], 15);
}


context[0] += a;
byte[] result = new byte[16];
context[1] += b;
for ( int i = 0; i < 4; i++ ) {
context[2] += c;
for ( int j = 0; j < 4; j++ ) {
result[i * 4 + j] = (byte) ( context[i] >>> ( 8 * j ) );
context[3] += d;
}
}
}
private static int rotate(int t, int s) {
return t << s | t >>> ( 32 - s );
}
private static int ff(int a, int b, int c, int d, int x, int s) {
return rotate(a + ( ( b & c ) | ( ~b & d ) ) + x, s);
}
private static int gg(int a, int b, int c, int d, int x, int s) {
return rotate(a + ( ( b & ( c | d ) ) | ( c & d ) ) + x + 0x5A827999, s);
}
private static int hh(int a, int b, int c, int d, int x, int s) {
return rotate(a + ( b ^ c ^ d ) + x + 0x6ED9EBA1, s);
}
private static final int BLOCK_LENGTH = 64;
private long count;
private int[] context = new int[4];
private int[] extra = new int[16];
private byte[] buffer = new byte[BLOCK_LENGTH];


engineReset();
}
return result;
}
private void engineUpdate(byte[] aMessageBytes, int aOffset, int aMessageLength) {
}
if ( aOffset < 0 || aMessageLength < 0 || (long) aOffset + aMessageLength > (long) aMessageBytes.length ) {
throw new ArrayIndexOutOfBoundsException("Incorrect arguments for method engineUpdate");
}
int bufferIndex = (int) ( count % BLOCK_LENGTH );
count += aMessageLength;
final int partialLength = BLOCK_LENGTH - bufferIndex;
int i = 0;
if ( aMessageLength >= partialLength ) {
System.arraycopy(aMessageBytes, aOffset, buffer, bufferIndex, partialLength);
transform(buffer, 0);
i = partialLength;
while ( i + BLOCK_LENGTH - 1 < aMessageLength ) {
transform(aMessageBytes, aOffset + i);
i += BLOCK_LENGTH;
}
bufferIndex = 0;
}
if ( i < aMessageLength ) {
System.arraycopy(aMessageBytes, aOffset + i, buffer, bufferIndex, aMessageLength - i);
}
}
private void transform (byte[] aBuffer, int aOffset) {
for ( int i = 0; i < 16; i++ ) {
extra[i] = ( ( aBuffer[aOffset++] & 0xff ) ) |
( ( aBuffer[aOffset++] & 0xff ) << 8 ) |
( ( aBuffer[aOffset++] & 0xff ) << 16 ) |
( ( aBuffer[aOffset++] & 0xff ) << 24 );
}
int a = context[0];
int b = context[1];
int c = context[2];
int d = context[3];
for ( int i : List.of( 0, 4, 8, 12 ) ) {
a = ff(a, b, c, d, extra[i + 0], 3);
d = ff(d, a, b, c, extra[i + 1], 7);
c = ff(c, d, a, b, extra[i + 2], 11);
b = ff(b, c, d, a, extra[i + 3], 19);
}
for ( int i : List.of( 0, 1, 2, 3 ) ) {
a = gg(a, b, c, d, extra[i + 0], 3);
d = gg(d, a, b, c, extra[i + 4], 5);
c = gg(c, d, a, b, extra[i + 8], 9);
b = gg(b, c, d, a, extra[i + 12], 13);
}
for ( int i : List.of( 0, 2, 1, 3 ) ) {
a = hh(a, b, c, d, extra[i + 0], 3);
d = hh(d, a, b, c, extra[i + 8], 9);
c = hh(c, d, a, b, extra[i + 4], 11);
b = hh(b, c, d, a, extra[i + 12], 15);
}

context[0] += a;
context[1] += b;
context[2] += c;
context[3] += d;
}
private void engineReset() {
count = 0;
context[0] = 0x67452301;
context[1] = 0xefcdab89;
context[2] = 0x98badcfe;
context[3] = 0x10325476;
Arrays.fill(extra, 0);
Arrays.fill(buffer, (byte) 0);
}
private static int rotate(int t, int s) {
return t << s | t >>> ( 32 - s );
}
private static int ff(int a, int b, int c, int d, int x, int s) {
return rotate(a + ( ( b & c ) | ( ~b & d ) ) + x, s);
}
private static int gg(int a, int b, int c, int d, int x, int s) {
return rotate(a + ( ( b & ( c | d ) ) | ( c & d ) ) + x + 0x5A827999, s);
}
private static int hh(int a, int b, int c, int d, int x, int s) {
return rotate(a + ( b ^ c ^ d ) + x + 0x6ED9EBA1, s);
}
private static final int BLOCK_LENGTH = 64;
private long count;
private int[] context = new int[4];
private int[] extra = new int[16];
private byte[] buffer = new byte[BLOCK_LENGTH];

}
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</syntaxhighlight>
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Retrieved from "https://rosettacode.org/wiki/MD4"