MD4: Difference between revisions
New post which does not use an external library. In addition to an existing post which uses the "BouncyCastle" library.
(Dialects of BASIC moved to the BASIC section.) |
(New post which does not use an external library. In addition to an existing post which uses the "BouncyCastle" library.) |
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}</syntaxhighlight>
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<pre>
a52bcfc6a0d0d300cdc5ddbfbefe478b
</pre>
===Without external libraries===
<syntaxhighlight lang="java">
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.List;
public final class MD4Task {
public static void main(String[] aArgs) {
String text = "Rosetta Code";
MD4 md = new MD4();
md.engineUpdate(text.getBytes(), 0, text.length());
byte[] result = md.engineDigest();
StringBuilder stringBuilder = new StringBuilder();
for ( byte bb : result) {
stringBuilder.append(String.format("%02x", bb));
}
System.out.println(stringBuilder.toString());
}
private static class MD4 extends MessageDigest {
public MD4() {
super("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 aByte) {
final int i = (int) ( count % BLOCK_LENGTH );
count++ ;
buffer[i] = aByte;
if ( i == BLOCK_LENGTH - 1 ) {
transform(buffer, 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);
}
}
@Override
protected byte[] engineDigest() {
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;
}
private void transform (byte[] aBlock, int aOffset) {
for ( int i = 0; i < 16; i++ ) {
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];
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 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];
}
}
</syntaxhighlight>
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<pre>
a52bcfc6a0d0d300cdc5ddbfbefe478b
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