Java 如何在此方法上使用 Cipher 来解密字符串？
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时间：2020-08-14 16:02:59 来源:igfitidea点击:
How to use Cipher on this Method to decrypt a String?
提问by hanso
Hello I build this 2 Methods the Encryption works fine but the Decryption get an error because cipher wants a byte and i want to encrypt from a String
您好，我构建了这 2 种方法，加密工作正常，但解密出错，因为密码需要一个字节，而我想从字符串加密
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
public class Test {
private byte[] encrypted;
private String encryptedtext;
private String decrypted;
public String Encrypt (String pInput) {
try {
String Input = pInput;
String key = "Bar12345Bar12345Bar12345Bar12345";
// Erstelle key and cipher
SecretKeySpec aesKey = new SecretKeySpec(key.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES");
// Verschlüsselung
cipher.init(Cipher.ENCRYPT_MODE, aesKey);
byte[] encrypted = cipher.doFinal(Input.getBytes());
encryptedtext = new String(encrypted);
System.err.println("encrypted:" + encryptedtext);
}catch(Exception e) {
e.printStackTrace();
}
return encrypted;
}
public String Decrypt (String pInput) {
try {
String Input = pInput;
String key = "Bar12345Bar12345Bar12345Bar12345";
// Erstelle key and cipher
SecretKeySpec aesKey = new SecretKeySpec(key.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES");
// Entschlüsselung
cipher.init(Cipher.DECRYPT_MODE, aesKey);
decrypted = new String(cipher.doFinal(encryptedtext)); // HERE IS THE PROBLEM IT WANT BYTE BUT I WANT TO ENCRYPT FROM A STRING
System.err.println("decrypted: " + decrypted);
}catch(Exception e) {
e.printStackTrace();
}
return pInput;
}
}
回答by tom87416
Byte array cannot directly convert to string, and neither do the reverse direction.
字节数组不能直接转换为字符串，反方向也不能。
import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
public class stackoverflow_test {
private byte[] encrypted;
private String encryptedtext;
private String decrypted;
public String Encrypt(String pInput) {
try {
String Input = pInput;
String key = "Bar12345Bar12345Bar12345Bar12345";
SecretKeySpec aesKey = new SecretKeySpec(key.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, aesKey);
byte[] encrypted = cipher.doFinal(Input.getBytes());
//encryptedtext = new String(encrypted);
encryptedtext = DatatypeConverter.printBase64Binary(encrypted);
System.err.println("encrypted:" + encryptedtext);
} catch (Exception e) {
e.printStackTrace();
}
return encryptedtext;
}
public String Decrypt(String pInput) {
try {
String Input = pInput;
String key = "Bar12345Bar12345Bar12345Bar12345";
SecretKeySpec aesKey = new SecretKeySpec(key.getBytes(), "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, aesKey);
encrypted = DatatypeConverter.parseBase64Binary(encryptedtext);
decrypted = new String(cipher.doFinal(encrypted));
System.err.println("decrypted: " + decrypted);
} catch (Exception e) {
e.printStackTrace();
}
return pInput;
}
public static void main(String[] ag){
stackoverflow_test test = new stackoverflow_test();
String a = test.Encrypt("Byte cannot directly convert to string");
String b = test.Decrypt(a);
}
}
Result
结果
encrypted:UmH+3eUagjrRDblxSStArnaktoxTLX+7qvPdwiTO7VggYmYtuXu/Ygww8ZG5SrDz
decrypted: Byte cannot directly convert to string
回答by Farid Haq
You can use Cipherto encrypt and decrypt a String.
您可以使用Cipher加密和解密String.
public class CryptUtil {
private static final String ALGORITHM = "Blowfish";
private static final String MODE = "Blowfish/CBC/PKCS5Padding";
private static final String IV = "abcdefgh";
public static String encrypt(String secretKey, String value ) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
SecretKeySpec secretKeySpec = new SecretKeySpec(secretKey.getBytes(), ALGORITHM);
Cipher cipher = Cipher.getInstance(MODE);
cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, new IvParameterSpec(IV.getBytes()));
byte[] values = cipher.doFinal(value.getBytes());
return Base64.encodeToString(values, Base64.DEFAULT);
}
public static String decrypt(String secretKey, String value) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
byte[] values = Base64.decode(value, Base64.DEFAULT);
SecretKeySpec secretKeySpec = new SecretKeySpec(secretKey.getBytes(), ALGORITHM);
Cipher cipher = Cipher.getInstance(MODE);
cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, new IvParameterSpec(IV.getBytes()));
return new String(cipher.doFinal(values));
}
}
