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turbidsoul/OpenSSL.java

Created March 23, 2013 08:32
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OpenSSL.java
package cn.is.ftp;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
/**
* Class created for StackOverflow by owlstead. This is open source, you are free to copy and use for any purpose.
*/
public class OpenSSLDecryptor {
private static final int INDEX_KEY = 0;
private static final int INDEX_IV = 1;
private static final int ITERATIONS = 1;
private static final int KEY_SIZE_BITS = 128;
/**
* Thanks go to Ola Bini for releasing this source on his blog. The source was obtained from <a
* href="http://olabini.com/blog/tag/evp_bytestokey/">here</a> .
*/
public static byte[][] EVP_BytesToKey(int key_len, int iv_len, MessageDigest md, byte[] salt, byte[] data, int count) {
byte[][] both = new byte[2][];
byte[] key = new byte[key_len];
int key_ix = 0;
byte[] iv = new byte[iv_len];
int iv_ix = 0;
both[0] = key;
both[1] = iv;
byte[] md_buf = null;
int nkey = key_len;
int niv = iv_len;
int i = 0;
if (data == null) {
return both;
}
int addmd = 0;
for (;;) {
md.reset();
if (addmd++ > 0) {
md.update(md_buf);
}
md.update(data);
if (null != salt) {
md.update(salt, 0, 8);
}
md_buf = md.digest();
for (i = 1; i < count; i++) {
md.reset();
md.update(md_buf);
md_buf = md.digest();
}
i = 0;
if (nkey > 0) {
for (;;) {
if (nkey == 0)
break;
if (i == md_buf.length)
break;
key[key_ix++] = md_buf[i];
nkey--;
i++;
}
}
if (niv > 0 && i != md_buf.length) {
for (;;) {
if (niv == 0)
break;
if (i == md_buf.length)
break;
iv[iv_ix++] = md_buf[i];
niv--;
i++;
}
}
if (nkey == 0 && niv == 0) {
break;
}
}
for (i = 0; i < md_buf.length; i++) {
md_buf[i] = 0;
}
return both;
}
public static byte[] encrypt(byte[] salt, byte[] contents, String pw) throws NoSuchAlgorithmException, NoSuchPaddingException,
InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
MessageDigest md5 = MessageDigest.getInstance("MD5");
final byte[][] keyAndIV = EVP_BytesToKey(KEY_SIZE_BITS / Byte.SIZE, aesCBC.getBlockSize(), md5, salt, pw.getBytes(), ITERATIONS);
SecretKeySpec key = new SecretKeySpec(keyAndIV[INDEX_KEY], "AES");
IvParameterSpec iv = new IvParameterSpec(keyAndIV[INDEX_IV]);
aesCBC.init(Cipher.ENCRYPT_MODE, key, iv);
return aesCBC.doFinal(contents);
}
public static byte[] decrypt(byte[] salt, byte[] encrypted, String pw) throws NoSuchAlgorithmException, NoSuchPaddingException,
InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
Cipher aesCBC = Cipher.getInstance("AES/CBC/PKCS5Padding");
MessageDigest md5 = MessageDigest.getInstance("MD5");
final byte[][] keyAndIV = EVP_BytesToKey(KEY_SIZE_BITS / Byte.SIZE, aesCBC.getBlockSize(), md5, salt, pw.getBytes(), ITERATIONS);
SecretKeySpec key = new SecretKeySpec(keyAndIV[INDEX_KEY], "AES");
IvParameterSpec iv = new IvParameterSpec(keyAndIV[INDEX_IV]);
aesCBC.init(Cipher.DECRYPT_MODE, key, iv);
return aesCBC.doFinal(encrypted);
}
public static void main(String[] args) throws Exception {
String pw = "AKeyForAES128CBC";
byte[] salt = "1234567890".getBytes();
byte[] encrypted = "Secret message! Oh, My GOD!".getBytes();
byte[] decrypted = encrypt(salt, encrypted, pw);
String str = Base16.encode(decrypted);
System.out.println(str);
String answer = new String(decrypt(salt, decrypted, pw));
System.out.println(answer);
answer = new String(decrypt(salt, Base16.decode(str), pw));
System.out.println(answer);
}
}
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