AES encryption and description

[code lang=”java”] import android.util.Base64; import javax.crypto.Cipher; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec; public class AESCrypt  { private final Cipher cipher; private final SecretKeySpec key; private AlgorithmParameterSpec spec; public AESCrypt(String password) throws Exception { // hash password with SHA-256 and crop the output to 128-bit for key MessageDigest digest = MessageDigest.getInstance(“SHA-256”); digest.update(password.getBytes(“UTF-8”)); byte[] keyBytes = new byte[32]; System.arraycopy(digest.digest(),…


[code lang=”java”]
import android.util.Base64;

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class AESCrypt  {

private final Cipher cipher;
private final SecretKeySpec key;
private AlgorithmParameterSpec spec;

public AESCrypt(String password) throws Exception {
// hash password with SHA-256 and crop the output to 128-bit for key
MessageDigest digest = MessageDigest.getInstance(“SHA-256”);
digest.update(password.getBytes(“UTF-8”));
byte[] keyBytes = new byte[32];
System.arraycopy(digest.digest(), 0, keyBytes, 0, keyBytes.length);

cipher = Cipher.getInstance(“AES/CBC/PKCS7Padding”);
key = new SecretKeySpec(keyBytes, “AES”);
spec = getIV();
}

public AlgorithmParameterSpec getIV() {
byte[] iv = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, };
IvParameterSpec ivParameterSpec;
ivParameterSpec = new IvParameterSpec(iv);
return ivParameterSpec;
}

public String encrypt(String plainText) throws Exception {
cipher.init(Cipher.ENCRYPT_MODE, key, spec);
byte[] encrypted = cipher.doFinal(plainText.getBytes(“UTF-8”));
String encryptedText = new String(Base64.encode(encrypted, Base64.DEFAULT),       “UTF-8”);
return encryptedText;
}

public String decrypt(String cryptedText) throws Exception {
cipher.init(Cipher.DECRYPT_MODE, key, spec);
byte[] bytes = Base64.decode(cryptedText, Base64.DEFAULT);
byte[] decrypted = cipher.doFinal(bytes);
String decryptedText = new String(decrypted, “UTF-8”);
return decryptedText;
}

}
[/code]


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