我必须加密字符串以通过HTTPS发送到服务器。然后，在服务器端，我必须解密字符串并使用它。
我在双方都使用了这段代码：
public class SimpleCrypto {
public static String encrypt(String seed, String cleartext) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] result = encrypt(rawKey, cleartext.getBytes());
return toHex(result);
}
public static String decrypt(String seed, String encrypted) throws Exception {
byte[] rawKey = getRawKey(seed.getBytes());
byte[] enc = toByte(encrypted);
byte[] result = decrypt(rawKey, enc);
return new String(result);
}
private static byte[] getRawKey(byte[] seed) throws Exception {
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(seed);
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] raw = skey.getEncoded();
return raw;
}
private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.ENCRYPT_MODE, skeySpec);
byte[] encrypted = cipher.doFinal(clear);
return encrypted;
}
private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception {
SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");
Cipher cipher = Cipher.getInstance("AES");
cipher.init(Cipher.DECRYPT_MODE, skeySpec);
byte[] decrypted = cipher.doFinal(encrypted);
return decrypted;
}
public static String toHex(String txt) {
return toHex(txt.getBytes());
}
public static String fromHex(String hex) {
return new String(toByte(hex));
}
public static byte[] toByte(String hexString) {
int len = hexString.length()/2;
byte[] result = new byte[len];
for (int i = 0; i < len; i++)
result[i] = Integer.valueOf(hexString.substring(2*i, 2*i+2), 16).byteValue();
return result;
}
public static String toHex(byte[] buf) {
if (buf == null)
return "";
StringBuffer result = new StringBuffer(2*buf.length);
for (int i = 0; i < buf.length; i++) {
appendHex(result, buf[i]);
}
return result.toString();
}
private final static String HEX = "0123456789ABCDEF";
private static void appendHex(StringBuffer sb, byte b) {
sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}
}
在android上，使用“123456789”作为种子，rawKey给我：
[99,51，-103，-58,81，-52,90，-103，-114,70，-128，-25，-105，-124，-128，-67]
但是在服务器端，使用相同的种子，请给我：
[ - 52,103,4,60,123，-49，-11，-18，-91,86,107，-39，-79，-13，-57,79]
我无法理解为什么。与Android上的javax.crypto.KeyGenerator不同吗？我做错了什么？
拜托，我需要一些帮助。
非常感谢
抱歉我的英语不好
----------------------------- UPDATE ----------------- ---------------------------------------
这是我的新代码：
public class DesEncrypter {
public static final int SALT_LENGTH = 20;
public static final int PBE_ITERATION_COUNT = 1024;
private static final String RANDOM_ALGORITHM = "SHA1PRNG";
private static final String PBE_ALGORITHM = "PBEWithSHA256And256BitAES-CBC-BC";
private static final String CIPHER_ALGORITHM = "AES/CBC/PKCS5Padding";
public byte[] encrypt(String password, String cleartext) {
byte[] encryptedText = null;
try {
byte[] salt = "dfghjklpoiuytgftgyhj".getBytes();
PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray(), salt, PBE_ITERATION_COUNT, 256);
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBEWITHSHAAND256BITAES-CBC-BC");
SecretKey tmp = factory.generateSecret(pbeKeySpec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
byte[] key = secret.getEncoded();
Cipher encryptionCipher = Cipher.getInstance(CIPHER_ALGORITHM);
byte[] iv = generateIv();
IvParameterSpec ivspec = new IvParameterSpec(iv);
encryptionCipher.init(Cipher.ENCRYPT_MODE, secret, ivspec);
encryptedText = encryptionCipher.doFinal(cleartext.getBytes());
} catch (Exception e) {
e.printStackTrace();
}
return encryptedText;
}
public String decrypt(String password, byte[] encryptedText) {
String cleartext = "";
try {
byte[] salt = "dfghjklpoiuytgftgyhj".getBytes();
PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray(), salt, PBE_ITERATION_COUNT, 256);
SecretKeyFactory factory = SecretKeyFactory.getInstance("PBEWITHSHAAND256BITAES-CBC-BC");
SecretKey tmp = factory.generateSecret(pbeKeySpec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
byte[] key = secret.getEncoded();
Cipher decryptionCipher = Cipher.getInstance(CIPHER_ALGORITHM);
byte[] iv = generateIv();
IvParameterSpec ivspec = new IvParameterSpec(iv);
decryptionCipher.init(Cipher.DECRYPT_MODE, secret, ivspec);
byte[] decryptedText = decryptionCipher.doFinal(encryptedText);
cleartext = new String(decryptedText);
} catch (Exception e) {
e.printStackTrace();
}
return cleartext;
}
private byte[] generateIv() throws NoSuchAlgorithmException {
SecureRandom random = SecureRandom.getInstance(RANDOM_ALGORITHM);
byte[] iv = new byte[16];
random.nextBytes(iv);
return iv;
}
}
----------------------------最终代码在ANDROID上工作！------------- -------------------
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.SecretKeySpec;
public class DesEncrypter {
public static final int SALT_LENGTH = 20;
public static final int PBE_ITERATION_COUNT = 200; //1024;
private static final String PBE_ALGORITHM = "PBEWithSHA256And256BitAES-CBC-BC";
//algoritmo / modo / relleno
private static final String CIPHER_ALGORITHM = "AES/CBC/PKCS5Padding";
byte[] iv = "1234567890asdfgh".getBytes();
byte[] salt = "dfghjklpoiuytgftgyhj".getBytes();
public byte[] encrypt(String password, String cleartext) {
byte[] encryptedText = null;
try {
PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray(), salt, PBE_ITERATION_COUNT, 256);
//Factoria para crear la SecretKey, debemos indicar el Algoritmo
SecretKeyFactory factory = SecretKeyFactory.getInstance(PBE_ALGORITHM);
SecretKey tmp = factory.generateSecret(pbeKeySpec);
//Creamos una llave;
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
//Obtenemos la llave, solo informativo
byte[] key = secret.getEncoded();
//La clase Cipher, se usa para cifrar mediante algoritmos de clave simétrica
Cipher encryptionCipher = Cipher.getInstance(CIPHER_ALGORITHM);
//byte[] iv = generateIv();
IvParameterSpec ivspec = new IvParameterSpec(iv);
//Accion, SecretKey, parameter specification for an initialization vector
encryptionCipher.init(Cipher.ENCRYPT_MODE, secret, ivspec);
//Realizamos el cifrado
encryptedText = encryptionCipher.doFinal(cleartext.getBytes());
} catch (Exception e) {
e.printStackTrace();
}
return encryptedText;
}
public String decrypt(String password, byte[] encryptedText) {
String cleartext = "";
try {
PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray(), salt, PBE_ITERATION_COUNT, 256);
//Factoria para crear la SecretKey, debemos indicar el Algoritmo
SecretKeyFactory factory = SecretKeyFactory.getInstance(PBE_ALGORITHM);
SecretKey tmp = factory.generateSecret(pbeKeySpec);
//Creamos una llave;
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
//Obtenemos la llave, solo informativo
byte[] key = secret.getEncoded();
//La clase Cipher, se usa para cifrar mediante algoritmos de clave simétrica
Cipher decryptionCipher = Cipher.getInstance(CIPHER_ALGORITHM);
//byte[] iv = generateIv();
IvParameterSpec ivspec = new IvParameterSpec(iv);
//Accion, SecretKey, parameter specification for an initialization vector
decryptionCipher.init(Cipher.DECRYPT_MODE, secret, ivspec);
//Realizamos el descifrado
byte[] decryptedText = decryptionCipher.doFinal(encryptedText);
cleartext = new String(decryptedText);
} catch (Exception e) {
e.printStackTrace();
}
return cleartext;
}
}
答案 0 :(得分：2)
如果您首先使用SSL，为什么要加密？ HTTPS（SSL）将对传输中的数据进行加密，并在服务器上自动解密。此外，您的自定义加密方案很可能不如SSL安全。
您的错误在于如何派生密钥：setSeed()不会替换随机数生成器的状态，它只会增加它。这意味着即使您将相同的字节传递给setSeed()，generateKey()也很可能会生成不同的密钥。使用PBE（基于密码的加密）类从密码派生密钥。或者确保您的服务器和客户端以其他方式使用相同的密钥。
这是从密码生成密钥的示例（适用于Android）。您需要找到Android和服务器上都支持的PBE算法。如果您在服务器应用程序中使用JCE Bouncy Castle提供程序，它应该支持与Android相同的算法（Android使用Bouncy Castle作为其部分JCE实现）。
SecretKeyFactory factory =
SecretKeyFactory.getInstance("PBEWITHSHAAND256BITAES-CBC-BC");
KeySpec spec = new PBEKeySpec("password".toCharArray(), salt, 1024, 256);
SecretKey tmp = factory.generateSecret(spec);
SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");