使用AES256对称块密码的图像加密/解密

问题描述

是否有一个很好的示例，说明如何在Android上使用AES 加密和解密图像和其他文件?

Is there any good example of how to encrypt and decrypt image and other files with AES on Android?

推荐答案

警告:此答案包含您不应该使用的代码，因为它是不安全的(使用SHA1PRNG进行密钥派生，并在ECB模式下使用AES)

改为(截至2016年)，使用PBKDF2WithHmacSHA1进行密钥派生，并在CBC或GCM模式下使用AES(GCM同时提供隐私和完整性)

您可以使用以下功能:

Warning: This answer contains code you should not use as it is insecure (using SHA1PRNG for key derivation and using AES in ECB mode)

Instead (as of 2016), use PBKDF2WithHmacSHA1 for key derivation and AES in CBC or GCM mode (GCM provides both privacy and integrity)

You could use functions like these:

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;
}

并像这样调用它们:

ByteArrayOutputStream baos = new ByteArrayOutputStream();
bm.compress(Bitmap.CompressFormat.PNG, 100, baos); // bm is the bitmap object
byte[] b = baos.toByteArray();

byte[] keyStart = "this is a key".getBytes();
KeyGenerator kgen = KeyGenerator.getInstance("AES");
SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");
sr.setSeed(keyStart);
kgen.init(128, sr); // 192 and 256 bits may not be available
SecretKey skey = kgen.generateKey();
byte[] key = skey.getEncoded();

// encrypt
byte[] encryptedData = encrypt(key,b);
// decrypt
byte[] decryptedData = decrypt(key,encryptedData);

这应该可行，我现在在一个项目中使用类似的代码.

This should work, I use similar code in a project right now.

这篇关于使用AES256对称块密码的图像加密/解密的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！