AES 与 Android 中的 Base64 密钥加密

Question

我正在制作一个 android 应用程序，我应该在其中加密我从用户那里获取的密码并将其发送到我的应用程序引擎。我想使用带有 Base64 密钥的 AES 技术。我是加密/解密的新手，所以我使用了question 中询问的代码。我换了钥匙，换成了我的。这是我的代码：

public String encrypt(String dataToEncrypt)
            throws NoSuchAlgorithmException, NoSuchPaddingException,
            InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
        // I'm using AES encription

        if (!dataToEncrypt.equals("")) {
            String key = "rEqrHrhdd9I1sg==";

            Cipher c = Cipher.getInstance("AES");
            SecretKeySpec k;
            try {
                k = new SecretKeySpec(key.getBytes(), "AES");
                c.init(Cipher.ENCRYPT_MODE, k);
            } catch (Exception e) {
                e.printStackTrace();
            }

            return new String(c.doFinal(Base64.decode(dataToEncrypt, 0)));
        }
        return "";
    }

但有时我在尝试加密某些字符串时收到错误“java.lang.IllegalArgumentException: bad base-64”，比如“asdasdasd”在我加密时会出现此错误。谁能告诉我问题是什么？？
-提前致谢

Answer 1

试试这个作为如何使用字符串作为键和消息的例子。至少它使用正确的（字符）编码，使用 CBC 模式和 PKCS5/7 填充。请注意，将加密的密码发送到服务器存在很多问题。通常，应该通过在服务器上使用 SSL 来实现机密性和 bcrypt 或 PBKDF2 来实现安全性（但这已在 stackoverflow 上一次又一次地介绍过）。

请注意，下面的代码不提供完整性检查或真实性 .

public static String encrypt(final String plainMessage,
        final String symKeyHex) {
    final byte[] symKeyData = DatatypeConverter.parseHexBinary(symKeyHex);

    final byte[] encodedMessage = plainMessage.getBytes(Charset
            .forName("UTF-8"));
    try {
        final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        final int blockSize = cipher.getBlockSize();

        // create the key
        final SecretKeySpec symKey = new SecretKeySpec(symKeyData, "AES");

        // generate random IV using block size (possibly create a method for
        // this)
        final byte[] ivData = new byte[blockSize];
        final SecureRandom rnd = SecureRandom.getInstance("SHA1PRNG");
        rnd.nextBytes(ivData);
        final IvParameterSpec iv = new IvParameterSpec(ivData);

        cipher.init(Cipher.ENCRYPT_MODE, symKey, iv);

        final byte[] encryptedMessage = cipher.doFinal(encodedMessage);

        // concatenate IV and encrypted message
        final byte[] ivAndEncryptedMessage = new byte[ivData.length
                + encryptedMessage.length];
        System.arraycopy(ivData, 0, ivAndEncryptedMessage, 0, blockSize);
        System.arraycopy(encryptedMessage, 0, ivAndEncryptedMessage,
                blockSize, encryptedMessage.length);

        final String ivAndEncryptedMessageBase64 = DatatypeConverter
                .printBase64Binary(ivAndEncryptedMessage);

        return ivAndEncryptedMessageBase64;
    } catch (InvalidKeyException e) {
        throw new IllegalArgumentException(
                "key argument does not contain a valid AES key");
    } catch (GeneralSecurityException e) {
        throw new IllegalStateException(
                "Unexpected exception during encryption", e);
    }
}

public static String decrypt(final String ivAndEncryptedMessageBase64,
        final String symKeyHex) {
    final byte[] symKeyData = DatatypeConverter.parseHexBinary(symKeyHex);

    final byte[] ivAndEncryptedMessage = DatatypeConverter
            .parseBase64Binary(ivAndEncryptedMessageBase64);
    try {
        final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        final int blockSize = cipher.getBlockSize();

        // create the key
        final SecretKeySpec symKey = new SecretKeySpec(symKeyData, "AES");

        // retrieve random IV from start of the received message
        final byte[] ivData = new byte[blockSize];
        System.arraycopy(ivAndEncryptedMessage, 0, ivData, 0, blockSize);
        final IvParameterSpec iv = new IvParameterSpec(ivData);

        // retrieve the encrypted message itself
        final byte[] encryptedMessage = new byte[ivAndEncryptedMessage.length
                - blockSize];
        System.arraycopy(ivAndEncryptedMessage, blockSize,
                encryptedMessage, 0, encryptedMessage.length);

        cipher.init(Cipher.DECRYPT_MODE, symKey, iv);

        final byte[] encodedMessage = cipher.doFinal(encryptedMessage);

        // concatenate IV and encrypted message
        final String message = new String(encodedMessage,
                Charset.forName("UTF-8"));

        return message;
    } catch (InvalidKeyException e) {
        throw new IllegalArgumentException(
                "key argument does not contain a valid AES key");
    } catch (BadPaddingException e) {
        // you'd better know about padding oracle attacks
        return null;
    } catch (GeneralSecurityException e) {
        throw new IllegalStateException(
                "Unexpected exception during decryption", e);
    }
}

Answer 2

simplecrypto.java

     import java.security.SecureRandom;
     import javax.crypto.Cipher;
     import javax.crypto.KeyGenerator;
     import javax.crypto.SecretKey;
     import javax.crypto.spec.SecretKeySpec;

     public class SimpleCrypto {

public  String encrypt(String seed, String cleartext) throws Exception {
        byte[] rawKey = getRawKey(seed.getBytes());
        byte[] result = encrypt(rawKey, cleartext.getBytes());
        return toHex(result);
}

public  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);
}

//done
private  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  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  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  String toHex(String txt) {
        return toHex(txt.getBytes());
}
public  String fromHex(String hex) {
        return new String(toByte(hex));
}

public  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  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  void appendHex(StringBuffer sb, byte b) {
        sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));
}

  }

在活动中请输入以下代码：

SimpleCrypto simpleCrypto = new SimpleCrypto();
    String s = "";
    try {
        s = simpleCrypto.encrypt("abc", "xyz");
    } catch (Exception e) {
        e.printStackTrace();
    }

abc是要加密的文本，xyz是加密密钥

Answer 3

看我的回答Android database encryption。它包含 2 个文件，您可以将它们包含在任何需要加密数据存储的应用程序中。有一种实现方法可以更轻松地将字节数组数据转换为可打印的 Base64 数据，反之亦然。使用 AES 算法和密码块链接 (CBC) 加密模式和 PKCS#5 填充。

Answer 4

您好，我重写了没有 DatatypeConverter 和 apache commons 的 owlstead java 方法示例。

public static String encrypt(final String plainMessage,
        final String symKeyHex) {


    try {

    final byte[] symKeyData = Hex.decodeHex(symKeyHex.toCharArray());

    final byte[] encodedMessage = plainMessage.getBytes(Charset.forName("UTF-8"));

        final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        final int blockSize = cipher.getBlockSize();

        // create the key
        final SecretKeySpec symKey = new SecretKeySpec(symKeyData, "AES");

        // generate random IV using block size (possibly create a method for
        // this)
        final byte[] ivData = new byte[blockSize];
        final SecureRandom rnd = SecureRandom.getInstance("SHA1PRNG");
        rnd.nextBytes(ivData);
        final IvParameterSpec iv = new IvParameterSpec(ivData);

        cipher.init(Cipher.ENCRYPT_MODE, symKey, iv);

        final byte[] encryptedMessage = cipher.doFinal(encodedMessage);

        // concatenate IV and encrypted message
        final byte[] ivAndEncryptedMessage = new byte[ivData.length
                + encryptedMessage.length];
        System.arraycopy(ivData, 0, ivAndEncryptedMessage, 0, blockSize);
        System.arraycopy(encryptedMessage, 0, ivAndEncryptedMessage,
                blockSize, encryptedMessage.length);

        final String ivAndEncryptedMessageBase64 = Base64.encodeBase64String(ivAndEncryptedMessage);

        return ivAndEncryptedMessageBase64;
    } catch (InvalidKeyException e) {
        throw new IllegalArgumentException(
                "key argument does not contain a valid AES key");
    } catch (GeneralSecurityException e) {
        throw new IllegalStateException(
                "Unexpected exception during encryption", e);
    } catch (DecoderException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return "";

}

public static String decrypt(final String ivAndEncryptedMessageBase64,
        final String symKeyHex) {

    try {
        final byte[] symKeyData = Hex.decodeHex(symKeyHex.toCharArray());
        final byte[] ivAndEncryptedMessage = Base64.decodeBase64(ivAndEncryptedMessageBase64);


        final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        final int blockSize = cipher.getBlockSize();

        // create the key
        final SecretKeySpec symKey = new SecretKeySpec(symKeyData, "AES");

        // retrieve random IV from start of the received message
        final byte[] ivData = new byte[blockSize];
        System.arraycopy(ivAndEncryptedMessage, 0, ivData, 0, blockSize);
        final IvParameterSpec iv = new IvParameterSpec(ivData);

        // retrieve the encrypted message itself
        final byte[] encryptedMessage = new byte[ivAndEncryptedMessage.length
                - blockSize];
        System.arraycopy(ivAndEncryptedMessage, blockSize,
                encryptedMessage, 0, encryptedMessage.length);

        cipher.init(Cipher.DECRYPT_MODE, symKey, iv);

        final byte[] encodedMessage = cipher.doFinal(encryptedMessage);

        // concatenate IV and encrypted message
        final String message = new String(encodedMessage,
                Charset.forName("UTF-8"));

        return message;
    } catch (InvalidKeyException e) {
        throw new IllegalArgumentException(
                "key argument does not contain a valid AES key");
    } catch (BadPaddingException e) {
        // you'd better know about padding oracle attacks
        return null;
    } catch (GeneralSecurityException e) {
        throw new IllegalStateException(
                "Unexpected exception during decryption", e);
    } catch (DecoderException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return "";
}

你甚至不能在 android 上使用它，因为 Base64 类可能有问题。在 android 上，您可以使用以下使用 Base64 android 类的方法：

public static String encrypt(final String plainMessage,
                             final String symKeyHex) {


    try {

        final byte[] symKeyData = Hex.decodeHex(symKeyHex.toCharArray());

        final byte[] encodedMessage = plainMessage.getBytes(Charset.forName("UTF-8"));

        final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        final int blockSize = cipher.getBlockSize();

        // create the key
        final SecretKeySpec symKey = new SecretKeySpec(symKeyData, "AES");

        // generate random IV using block size (possibly create a method for
        // this)
        final byte[] ivData = new byte[blockSize];
        final SecureRandom rnd = SecureRandom.getInstance("SHA1PRNG");
        rnd.nextBytes(ivData);
        final IvParameterSpec iv = new IvParameterSpec(ivData);

        cipher.init(Cipher.ENCRYPT_MODE, symKey, iv);

        final byte[] encryptedMessage = cipher.doFinal(encodedMessage);

        // concatenate IV and encrypted message
        final byte[] ivAndEncryptedMessage = new byte[ivData.length
                + encryptedMessage.length];
        System.arraycopy(ivData, 0, ivAndEncryptedMessage, 0, blockSize);
        System.arraycopy(encryptedMessage, 0, ivAndEncryptedMessage,
                blockSize, encryptedMessage.length);

        //final String ivAndEncryptedMessageBase64 = Base64.encodeBase64String(ivAndEncryptedMessage);
        final String ivAndEncryptedMessageBase64 = Base64.encodeToString(ivAndEncryptedMessage,Base64.DEFAULT);

        return ivAndEncryptedMessageBase64;
    } catch (InvalidKeyException e) {
        throw new IllegalArgumentException(
                "key argument does not contain a valid AES key");
    } catch (GeneralSecurityException e) {
        throw new IllegalStateException(
                "Unexpected exception during encryption", e);
    } catch (DecoderException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return "";

}

public static String decrypt(final String ivAndEncryptedMessageBase64,
                             final String symKeyHex) {


    try {

        final byte[] symKeyData = Hex.decodeHex(symKeyHex.toCharArray());
        //final byte[] ivAndEncryptedMessage = Base64.decodeBase64(ivAndEncryptedMessageBase64);
        final byte[] ivAndEncryptedMessage = Base64.decode(ivAndEncryptedMessageBase64,Base64.DEFAULT);

        final Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        final int blockSize = cipher.getBlockSize();

        // create the key
        final SecretKeySpec symKey = new SecretKeySpec(symKeyData, "AES");

        // retrieve random IV from start of the received message
        final byte[] ivData = new byte[blockSize];
        System.arraycopy(ivAndEncryptedMessage, 0, ivData, 0, blockSize);
        final IvParameterSpec iv = new IvParameterSpec(ivData);

        // retrieve the encrypted message itself
        final byte[] encryptedMessage = new byte[ivAndEncryptedMessage.length
                - blockSize];
        System.arraycopy(ivAndEncryptedMessage, blockSize,
                encryptedMessage, 0, encryptedMessage.length);

        cipher.init(Cipher.DECRYPT_MODE, symKey, iv);

        final byte[] encodedMessage = cipher.doFinal(encryptedMessage);

        // concatenate IV and encrypted message
        final String message = new String(encodedMessage,
                Charset.forName("UTF-8"));

        return message;
    } catch (InvalidKeyException e) {
        throw new IllegalArgumentException(
                "key argument does not contain a valid AES key");
    } catch (BadPaddingException e) {
        // you'd better know about padding oracle attacks
        return null;
    } catch (GeneralSecurityException e) {
        throw new IllegalStateException(
                "Unexpected exception during decryption", e);
    } catch (DecoderException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    return "";
}

希望对您有所帮助！