解密在android上加密的桌面上的数据

我有一个应用程序，它加密一些文本字符串，然后将它们写入文件。 应用程序的桌面版本正在读取文件并解密数据。 问题是，无论何时我在桌面版本上解密，我都会得到一个“javax.crypto.BadPaddingException：给定最终块没有正确填充”

应用程序和桌面都使用相同的代码：

import java.security.SecureRandom; import javax.crypto.Cipher; import javax.crypto.KeyGenerator; import javax.crypto.SecretKey; import javax.crypto.spec.SecretKeySpec; public class SSL { private final static String HEX = "0123456789ABCDEF"; public static String encrypt(Session current, String cleartext) throws Exception { byte[] rawKey = getRawKey(current.getCurrentSession().getBytes()); byte[] result = encrypt(rawKey, cleartext.getBytes()); return toHex(result); } public static String decrypt(Session current, String encrypted) throws Exception { byte[] rawKey = getRawKey(current.getCurrentSession().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 >4)&0x0f)).append(HEX.charAt(b&0x0f)); } } 

为什么我不能解密桌面版的数据？ Android SDK和java 1.7中的加密实现是否有所不同？

注意：如果我在android上解密加密的android数据，它就可以了。 如果我在桌面上加密和解密，它也可以。 问题似乎介于这两者之间。

Answer 1

我终于找到了整个解决方案。

有一些重大问题，我想在这里解释一下，以便更多用户可以找到答案。 首先，Duncan指出的两件事需要修复。

在解决了这些问题后，我仍然遇到了同样的问题，并发现使用伪随机数创建原始密钥的方式不同，不同的平台/操作系统。 如果您希望具有跨平台独立性，请不要使用SHA1PRNG作为密钥算法。 相反，使用PBEWithSHA256And256BitAES-CBC-BC。 我正在使用BouncyCastle的实现，请参阅下面的完整加密代码。

 import java.io.UnsupportedEncodingException; import java.security.Security; import java.security.spec.KeySpec; import java.util.Random; 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; import org.bouncycastle.jce.provider.BouncyCastleProvider; public class SSL { private final static String HEX = "0123456789ABCDEF"; private final static String ENC = "US-ASCII"; private final static int ITERATION = 1337; private static final String RANDOM_ALGORITHM = "PBEWithSHA256And256BitAES-CBC-BC"; private static final String CIPHER_ALGORITHM = "AES/CBC/PKCS5Padding"; private static final String SECRET_KEY_ALGORITHM = "AES"; private static IvParameterSpec ips; public static void init(byte[] iv) { if(iv == null) { iv = new byte[16]; Random random = new Random(); random.nextBytes(iv); } ips = new IvParameterSpec(iv); Security.addProvider(new BouncyCastleProvider()); } public static byte[] getCertificate() { return ips.getIV(); } public static String encrypt(Session current, String cleartext) throws Exception { byte[] rawKey = getRawKey(current.getCurrentSession().toCharArray()); byte[] result = encrypt(rawKey, cleartext.getBytes(ENC)); return toHex(result); } public static String decrypt(Session current, String encrypted) throws Exception { byte[] rawKey = getRawKey(current.getCurrentSession().toCharArray()); byte[] enc = toByte(encrypted); byte[] result = decrypt(rawKey, enc); return new String(result, ENC); } private static byte[] getRawKey(char[] seed) throws Exception { KeySpec keySpec = new PBEKeySpec(seed, ips.getIV(), ITERATION); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance(RANDOM_ALGORITHM); byte[] keyBytes = keyFactory.generateSecret(keySpec).getEncoded(); SecretKey secretKey = new SecretKeySpec(keyBytes, "AES"); return secretKey.getEncoded(); } private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, SECRET_KEY_ALGORITHM); Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM); cipher.init(Cipher.ENCRYPT_MODE, skeySpec, ips); byte[] encrypted = cipher.doFinal(clear); return encrypted; } private static byte[] decrypt(byte[] raw, byte[] encrypted) throws Exception { SecretKeySpec skeySpec = new SecretKeySpec(raw, SECRET_KEY_ALGORITHM); Cipher cipher = Cipher.getInstance(CIPHER_ALGORITHM); cipher.init(Cipher.DECRYPT_MODE, skeySpec, ips); byte[] decrypted = cipher.doFinal(encrypted); return decrypted; } public static String toHex(String txt) throws UnsupportedEncodingException { return toHex(txt.getBytes(ENC)); } public static String fromHex(String hex) throws UnsupportedEncodingException { return new String(toByte(hex), ENC); } 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 static void appendHex(StringBuffer sb, byte b) { sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f)); } } 

Answer 2

您的代码至少存在两个问题，这些问题会影响其在不同平台上的function：

1. 调用getBytes()或new String(...)时必须指定一个字符集。 如果没有这个，如果您的平台具有不同的默认字符集，结果将会不同。

2. 您必须完全指定加密算法，例如将"AES"替换为"AES/CBC/PKCS5Padding"以避免提供商之间的差异。