在Android中使用Base64密钥加密的AES

Question

我正在创建一个Android应用程序，我应该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AES技术和Base64密钥。我是加密/解密的新手，所以我使用了question中提到的代码。我换了钥匙，换成了我的钥匙。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 "";
    }

但是当我尝试加密某些字符串时，有时会收到错误“java.lang.IllegalArgumentException：bad base-64”，说“asdasdasd”在我加密时会出现此错误。谁能告诉我这是什么问题？ - 提前谢谢

Answer 1

尝试将此作为如何将字符串用于键和消息的示例。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进行机密性和使用bcrypt或PBKDF2来实现安全性（但这已经在stackoverflow上一次又一次地被覆盖）。

请注意，以下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));
}

  }

并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是加密的密钥

Answer 3

在这里查看我的答案Android database encryption。它包含2个文件，您可以将这些文件包含在需要加密数据存储的任何应用程序中。实现的方法使得更容易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

您好我在没有DatatypeConverter和apache commons的情况下重写了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 "";
}

你甚至无法在Android上使用它，因为你可能会遇到Base64 Class的问题。在Android上你可以使用以下使用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 "";
}

希望这有帮助！