JAVA MD5加密例子

package md5;

import java.io.IOException;
import java.security.MessageDigest;

class MD5State {
int state[];
int count[];
byte buffer[];

public MD5State() {
buffer = new byte[64];
count = new int[2];
state = new int[4];

state[0] = 0x67452301;
state[1] = 0xefcdab89;
state[2] = 0x98badcfe;
state[3] = 0x10325476;

count[0] = count[1] = 0;
}

/** Create this State as a copy of another state */
public MD5State(MD5State from) {
this();

int i;

for (i = 0; i < buffer.length; i++)
this.buffer[i] = from.buffer[i];

for (i = 0; i < state.length; i++)
this.state[i] = from.state[i];

for (i = 0; i < count.length; i++)
this.count[i] = from.count[i];
}
};

public class MD5 {
/**
* MD5 state
*/
MD5State state;

/**
* If Final() has been called, finals is set to the current finals state.
* Any Update() causes this to be set to null.
*/
MD5State finals;

/**
* Padding for Final()
*/
static byte padding[] = { (byte) 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0 };

/**
* Initialize MD5 internal state (object can be reused just by calling
* Init() after every Final()
*/
public synchronized void Init() {
state = new MD5State();
finals = null;
}

public MD5() {
this.Init();
}

public MD5(Object ob) {
this();
Update(ob.toString());
}

public String debugDump() {
return asHex();
}

private int rotate_left(int x, int n) {
return (x << n) | (x >>> (32 - n));
}

/*
* I wonder how many loops and hoops you'll have to go through to get
* unsigned add for longs in java
*/

private int uadd(int a, int b) {
long aa, bb;
aa = ((long) a) & 0xffffffffL;
bb = ((long) b) & 0xffffffffL;

aa += bb;

return (int) (aa & 0xffffffffL);
}

private int uadd(int a, int b, int c) {
return uadd(uadd(a, b), c);
}

private int uadd(int a, int b, int c, int d) {
return uadd(uadd(a, b, c), d);
}

private int FF(int a, int b, int c, int d, int x, int s, int ac) {
a = uadd(a, ((b & c) | (~b & d)), x, ac);
return uadd(rotate_left(a, s), b);
}

private int GG(int a, int b, int c, int d, int x, int s, int ac) {
a = uadd(a, ((b & d) | (c & ~d)), x, ac);
return uadd(rotate_left(a, s), b);
}

private int HH(int a, int b, int c, int d, int x, int s, int ac) {
a = uadd(a, (b ^ c ^ d), x, ac);
return uadd(rotate_left(a, s), b);
}

private int II(int a, int b, int c, int d, int x, int s, int ac) {
a = uadd(a, (c ^ (b | ~d)), x, ac);
return uadd(rotate_left(a, s), b);
}

private int[] Decode(byte buffer[], int len, int shift) {
int out[];
int i, j;

out = new int[16];

for (i = j = 0; j < len; i++, j += 4) {
out[i] = ((int) (buffer[j + shift] & 0xff))
| (((int) (buffer[j + 1 + shift] & 0xff)) <<
| (((int) (buffer[j + 2 + shift] & 0xff)) << 16)
| (((int) (buffer[j + 3 + shift] & 0xff)) << 24);
}

return out;
}

private void Transform(MD5State state, byte buffer[], int shift) {
int a = state.state[0], b = state.state[1], c = state.state[2], d = state.state[3], x[];

x = Decode(buffer, 64, shift);

/* Round 1 */
a = FF(a, b, c, d, x[0], 7, 0xd76aa478); /* 1 */
d = FF(d, a, b, c, x[1], 12, 0xe8c7b756); /* 2 */
c = FF(c, d, a, b, x[2], 17, 0x242070db); /* 3 */
b = FF(b, c, d, a, x[3], 22, 0xc1bdceee); /* 4 */
a = FF(a, b, c, d, x[4], 7, 0xf57c0faf); /* 5 */
d = FF(d, a, b, c, x[5], 12, 0x4787c62a); /* 6 */
c = FF(c, d, a, b, x[6], 17, 0xa8304613); /* 7 */
b = FF(b, c, d, a, x[7], 22, 0xfd469501); /* 8 */
a = FF(a, b, c, d, x[8], 7, 0x698098d8); /* 9 */
d = FF(d, a, b, c, x[9], 12, 0x8b44f7af); /* 10 */
c = FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
b = FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
a = FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
d = FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
c = FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
b = FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */

/* Round 2 */
a = GG(a, b, c, d, x[1], 5, 0xf61e2562); /* 17 */
d = GG(d, a, b, c, x[6], 9, 0xc040b340); /* 18 */
c = GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
b = GG(b, c, d, a, x[0], 20, 0xe9b6c7aa); /* 20 */
a = GG(a, b, c, d, x[5], 5, 0xd62f105d); /* 21 */
d = GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */
c = GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
b = GG(b, c, d, a, x[4], 20, 0xe7d3fbc8); /* 24 */
a = GG(a, b, c, d, x[9], 5, 0x21e1cde6); /* 25 */
d = GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
c = GG(c, d, a, b, x[3], 14, 0xf4d50d87); /* 27 */
b = GG(b, c, d, a, x[8], 20, 0x455a14ed); /* 28 */
a = GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
d = GG(d, a, b, c, x[2], 9, 0xfcefa3f8); /* 30 */
c = GG(c, d, a, b, x[7], 14, 0x676f02d9); /* 31 */
b = GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */

/* Round 3 */
a = HH(a, b, c, d, x[5], 4, 0xfffa3942); /* 33 */
d = HH(d, a, b, c, x[8], 11, 0x8771f681); /* 34 */
c = HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
b = HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
a = HH(a, b, c, d, x[1], 4, 0xa4beea44); /* 37 */
d = HH(d, a, b, c, x[4], 11, 0x4bdecfa9); /* 38 */
c = HH(c, d, a, b, x[7], 16, 0xf6bb4b60); /* 39 */
b = HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
a = HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
d = HH(d, a, b, c, x[0], 11, 0xeaa127fa); /* 42 */
c = HH(c, d, a, b, x[3], 16, 0xd4ef3085); /* 43 */
b = HH(b, c, d, a, x[6], 23, 0x4881d05); /* 44 */
a = HH(a, b, c, d, x[9], 4, 0xd9d4d039); /* 45 */
d = HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
c = HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
b = HH(b, c, d, a, x[2], 23, 0xc4ac5665); /* 48 */

/* Round 4 */
a = II(a, b, c, d, x[0], 6, 0xf4292244); /* 49 */
d = II(d, a, b, c, x[7], 10, 0x432aff97); /* 50 */
c = II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
b = II(b, c, d, a, x[5], 21, 0xfc93a039); /* 52 */
a = II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
d = II(d, a, b, c, x[3], 10, 0x8f0ccc92); /* 54 */
c = II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
b = II(b, c, d, a, x[1], 21, 0x85845dd1); /* 56 */
a = II(a, b, c, d, x[8], 6, 0x6fa87e4f); /* 57 */
d = II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
c = II(c, d, a, b, x[6], 15, 0xa3014314); /* 59 */
b = II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
a = II(a, b, c, d, x[4], 6, 0xf7537e82); /* 61 */
d = II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
c = II(c, d, a, b, x[2], 15, 0x2ad7d2bb); /* 63 */
b = II(b, c, d, a, x[9], 21, 0xeb86d391); /* 64 */

state.state[0] += a;
state.state[1] += b;
state.state[2] += c;
state.state[3] += d;
}

public void Update(MD5State stat, byte buffer[], int offset, int length) {
int index, partlen, i, start;

finals = null;

/* Length can be told to be shorter, but not inter */
if ((length - offset) > buffer.length)
length = buffer.length - offset;

/* compute number of bytes mod 64 */
index = (int) (stat.count[0] >>> 3) & 0x3f;

if ((stat.count[0] += (length << 3)) < (length << 3))
stat.count[1]++;

stat.count[1] += length >>> 29;

partlen = 64 - index;

if (length >= partlen) {
for (i = 0; i < partlen; i++)
stat.buffer[i + index] = buffer[i + offset];

Transform(stat, stat.buffer, 0);

for (i = partlen; (i + 63) < length; i += 64)
Transform(stat, buffer, i);

index = 0;
} else
i = 0;

/* buffer remaining input */
if (i < length) {
start = i;
for (; i < length; i++)
stat.buffer[index + i - start] = buffer[i + offset];
}
}

public void Update(byte buffer[], int offset, int length) {
Update(this.state, buffer, offset, length);
}

public void Update(byte buffer[], int length) {
Update(this.state, buffer, 0, length);
}

public void Update(byte buffer[]) {
Update(buffer, 0, buffer.length);
}

public void Update(byte b) {
byte buffer[] = new byte[1];
buffer[0] = b;

Update(buffer, 1);
}

public void Update(String s) {
byte chars[];

chars = s.getBytes();

Update(chars, chars.length);
}

private byte[] Encode(int input[], int len) {
int i, j;
byte out[];

out = new byte[len];

for (i = j = 0; j < len; i++, j += 4) {
out[j] = (byte) (input[i] & 0xff);
out[j + 1] = (byte) ((input[i] >>> & 0xff);
out[j + 2] = (byte) ((input[i] >>> 16) & 0xff);
out[j + 3] = (byte) ((input[i] >>> 24) & 0xff);
}

return out;
}
public synchronized byte[] Final() {
byte bits[];
int index, padlen;
MD5State fin;

if (null == finals) {
fin = new MD5State(state);

bits = Encode(fin.count,;

index = (int) ((fin.count[0] >>> 3) & 0x3f);
padlen = (index < 56) ? (56 - index) : (120 - index);

Update(fin, padding, 0, padlen);
/**/
Update(fin, bits, 0,;

/* Update() sets finalds to null */
finals = fin;
}

return Encode(finals.state, 16);
}
public static String asHex(byte hash[]) {
StringBuilder buf = new StringBuilder(hash.length * 2);
int i;

for (i = 0; i < hash.length; i++) {
if (((int) hash[i] & 0xff) < 0x10)
buf.append("0");

buf.append(Long.toString((int) hash[i] & 0xff, 16));
}

return buf.toString();
}
public String asHex() {
return asHex(this.Final());
}

public static String md5crypt(String input) {
MD5 md5 = new MD5();
md5.Init();
md5.Update(input);
return md5.asHex();
}

public static String encodePassword(String password, String algorithm) {
byte[] unencodedPassword = password.getBytes();
MessageDigest md = null;
try {
// first create an instance, given the provider
md = MessageDigest.getInstance(algorithm);
} catch (Exception e) {
System.out.println(e.getMessage());
return password;
}
md.reset();
// call the update method one or more times
// (useful when you don't know the size of your data, eg. stream)
md.update(unencodedPassword);
// now calculate the hash
byte[] encodedPassword = md.digest();
StringBuffer buf = new StringBuffer();
for (int i = 0; i < encodedPassword.length; i++) {
if ((encodedPassword[i] & 0xff) < 0x10) {
buf.append("0");
}
buf.append(Long.toString(encodedPassword[i] & 0xff, 16));
}
return buf.toString();
}

public static String encodeString(String str) {
sun.misc.BASE64Encoder encoder = new sun.misc.BASE64Encoder();
return encoder.encodeBuffer(str.getBytes()).trim();
}

public static String decodeString(String str) {
sun.misc.BASE64Decoder dec = new sun.misc.BASE64Decoder();
try {
return new String(dec.decodeBuffer(str));
} catch (IOException io) {
throw new RuntimeException(io.getMessage(), io.getCause());
}
}

/**
* 算法可以使用：SHA-512，MD5，SHA-256等
* @param args
*/
public static void main(String[] args) {
String passwd = "admin";
String encodeString = encodePassword(passwd, "MD5");
System.out.println(encodeString);
System.out.println(md5crypt(passwd));
}
}