Java Tutorial/Security/MessageDigest
Содержание
Create an encrypted string for password
<source lang="java">
import java.security.MessageDigest; public class Main {
public static void main(String[] args) throws Exception {
String password = "secret";
String algorithm = "SHA";
byte[] plainText = password.getBytes();
MessageDigest md = MessageDigest.getInstance(algorithm);
md.reset();
md.update(plainText);
byte[] encodedPassword = md.digest();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < encodedPassword.length; i++) {
if ((encodedPassword[i] & 0xff) < 0x10) {
sb.append("0");
}
sb.append(Long.toString(encodedPassword[i] & 0xff, 16));
}
System.out.println("Plain : " + password);
System.out.println("Encrypted: " + sb.toString());
}
}</source>
Cryptography Streams: URLDigest
<source lang="java">
import java.io.InputStream; import java.math.BigInteger; import java.net.URL; import java.security.MessageDigest; import java.util.Arrays; public class Main {
public static void main(String[] args) throws Exception {
URL u = new URL("http://www.google.ru");
InputStream in = u.openStream();
MessageDigest sha = MessageDigest.getInstance("SHA");
byte[] data = new byte[1024];
int bytesRead = -1;
while ((bytesRead = in.read(data)) >= 0) {
sha.update(data, 0, bytesRead);
}
byte[] result = sha.digest();
System.out.println(Arrays.toString(result));
System.out.println(new BigInteger(result));
}
}</source>
Digest Input
<source lang="java">
import java.io.FileInputStream; import java.security.DigestInputStream; import java.security.MessageDigest; public class MainClass {
public static void main(String args[]) throws Exception {
MessageDigest m = MessageDigest.getInstance("MD5");
FileInputStream fin = new FileInputStream(args[0]);
DigestInputStream din = new DigestInputStream(fin, m);
while (din.read() != -1)
;
byte s[] = m.digest();
for (int i = 0; i < s.length; i++) {
System.out.print( Integer.toHexString((0x000000ff & s[i]) | 0xffffff00).substring(6));
}
}
}</source>
Digest Stream
<source lang="java">
import java.io.FileInputStream; import java.io.FileOutputStream; import java.security.DigestInputStream; import java.security.DigestOutputStream; import java.security.MessageDigest; public class MainClass {
public static void main(String[] args) throws Exception{
performOutputTest();
performInputTest();
}
static void performOutputTest() throws Exception {
MessageDigest md = MessageDigest.getInstance("SHA");
FileOutputStream fout = new FileOutputStream("sha-results.txt");
DigestOutputStream out = new DigestOutputStream(fout, md);
byte[] b = "testCase".getBytes();
out.write(b, 0, b.length);
md = out.getMessageDigest();
String s = new String(md.digest());
System.out.println("Calculated result: " + s);
}
static void performInputTest() throws Exception{
MessageDigest md = MessageDigest.getInstance("SHA");
FileInputStream fin = new FileInputStream("sha-results.txt");
DigestInputStream in = new DigestInputStream(fin, md);
byte[] b = new byte["testCase".getBytes().length];
in.read(b, 0, "testCase".getBytes().length);
md = in.getMessageDigest();
String s = new String(md.digest());
System.out.println("Calculated result: " + s);
}
}</source>
extends MessageDigest
<source lang="java">
import java.security.MessageDigest; public class XYZMessageDigest extends MessageDigest implements Cloneable {
private int hash;
private int store;
private int nBytes;
public XYZMessageDigest() {
super("XYZ");
engineReset();
}
public void engineUpdate(byte b) {
switch (nBytes) {
case 0:
store = (b << 24) & 0xff000000;
break;
case 1:
store |= (b << 16) & 0x00ff0000;
break;
case 2:
store |= (b << 8) & 0x0000ff00;
break;
case 3:
store |= (b << 0) & 0x000000ff;
break;
}
nBytes++;
if (nBytes == 4) {
hash = hash ^ store;
nBytes = 0;
store = 0;
}
}
public void engineUpdate(byte b[], int offset, int length) {
for (int i = 0; i < length; i++)
engineUpdate(b[i + offset]);
}
public void engineReset() {
hash = 0;
store = 0;
nBytes = 0;
}
public byte[] engineDigest() {
while (nBytes != 0)
engineUpdate((byte) 0);
byte b[] = new byte[4];
b[0] = (byte) (hash >>> 24);
b[1] = (byte) (hash >>> 16);
b[2] = (byte) (hash >>> 8);
b[3] = (byte) (hash >>> 0);
engineReset();
return b;
}
}</source>
Make SHA Message
<source lang="java">
import java.io.ByteArrayOutputStream; import java.io.DataOutputStream; import java.io.IOException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class MainClass {
public static byte[] makeDigest(byte[] mush, long t2, double q2) throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance("SHA");
md.update(mush);
md.update(makeBytes(t2, q2));
return md.digest();
}
}</source>
Make SHA Message with update methods
<source lang="java">
import java.io.ByteArrayOutputStream; import java.io.DataOutputStream; import java.io.IOException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class MainClass {
public static byte[] makeDigest(String user, String password, long t1, double q1)
throws NoSuchAlgorithmException {
MessageDigest md = MessageDigest.getInstance("SHA");
md.update(user.getBytes());
md.update(password.getBytes());
md.update(makeBytes(t1, q1));
return md.digest();
}
}</source>
Masher a file
<source lang="java">
import java.io.FileInputStream; import java.security.MessageDigest; import sun.misc.BASE64Encoder; public class MainClass {
public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.out.println("Usage: Masher filename");
return;
}
MessageDigest md = MessageDigest.getInstance("MD5");
FileInputStream in = new FileInputStream(args[0]);
byte[] buffer = new byte[8192];
int length;
while ((length = in.read(buffer)) != -1)
md.update(buffer, 0, length);
byte[] raw = md.digest();
BASE64Encoder encoder = new BASE64Encoder();
String base64 = encoder.encode(raw);
System.out.println(base64);
}
}</source>
MD5 MessageDigest
<source lang="java">
import java.security.MessageDigest; public class MainClass {
public static void main(String args[]) throws Exception {
MessageDigest m = MessageDigest.getInstance("MD5");
m.update("test".getBytes());
byte s[] = m.digest();
String result = "";
for (int i = 0; i < s.length; i++) {
result += Integer.toHexString((0x000000ff & s[i]) | 0xffffff00).substring(6);
}
System.out.println(result);
}
} //098f6bcd4621d373cade4e832627b4f6</source>
Message Digest Demo
<source lang="java">
import java.io.BufferedInputStream; import java.io.FileInputStream; import java.security.DigestInputStream; import java.security.MessageDigest; public class MainClass {
private static int BUFFER_SIZE = 32 * 1024;
public static void main(String[] args) throws Exception {
System.out.println("test.txt: " + md("text.txt"));
}
public static String md(String f) throws Exception {
BufferedInputStream file = new BufferedInputStream(new FileInputStream(f));
MessageDigest md = MessageDigest.getInstance("MD5");
DigestInputStream in = new DigestInputStream(file, md);
int i;
byte[] buffer = new byte[BUFFER_SIZE];
do {
i = in.read(buffer, 0, BUFFER_SIZE);
} while (i == BUFFER_SIZE);
md = in.getMessageDigest();
in.close();
return new String(md.digest());
}
}</source>
