我曾尝试在两个(Android 和 IPhone)平台上使用 AES 算法生成加密文本，但问题是即使我们使用相同的加密解密库 (AES-128) 并使用相同的固定变量(Key、IV、模式)，但我得到了两个不同的结果。

感谢任何帮助。 :(

下面的代码展示了使用的加密和解密方法，

Android 代码版本:

• 键 = “123456789abcdefg” ;
  • IV = “1111111111111111” ;
  • 纯文本 = “HelloThere”；
  • 模式 = “AES/CBC/NoPadding” ;

代码:

  public class Crypto {
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(“CBC”);
        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));
}

iPhone 代码版本:

- (NSData *) transform:(CCOperation) encryptOrDecrypt data:(NSData *) inputData {

NSData* secretKey = [Cipher md5:cipherKey];

CCCryptorRef cryptor = NULL;
CCCryptorStatus status = kCCSuccess;

uint8_t iv[kCCBlockSizeAES128];
memset((void *) iv, 0x0, (size_t) sizeof(iv));

status = CCCryptorCreate(encryptOrDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,
                         [secretKey bytes], kCCKeySizeAES128, iv, &cryptor);

if (status != kCCSuccess) {
    return nil;
}

size_t bufsize = CCCryptorGetOutputLength(cryptor, (size_t)[inputData length], true);

void * buf = malloc(bufsize * sizeof(uint8_t));
memset(buf, 0x0, bufsize);

size_t bufused = 0;
size_t bytesTotal = 0;

status = CCCryptorUpdate(cryptor, [inputData bytes], (size_t)[inputData length],
                         buf, bufsize, &bufused);

if (status != kCCSuccess) {
    free(buf);
    CCCryptorRelease(cryptor);
    return nil;
}

bytesTotal += bufused;

status = CCCryptorFinal(cryptor, buf + bufused, bufsize - bufused, &bufused);

if (status != kCCSuccess) {
    free(buf);
    CCCryptorRelease(cryptor);
    return nil;
}

bytesTotal += bufused;

CCCryptorRelease(cryptor);

return [NSData dataWithBytesNoCopy:buf length:bytesTotal];

 + (NSData *) md5:(NSString *) stringToHash {

const char *src = [stringToHash UTF8String];

unsigned char result[CC_MD5_DIGEST_LENGTH];

CC_MD5(src, strlen(src), result);

return [NSData dataWithBytes:result length:CC_MD5_DIGEST_LENGTH];

我的一些引用:

• http://automagical.rationalmind.net/2009/02/12/aes-interoperability-between-net-and-iphone/

• http://code.google.com/p/aes-encryption-samples/wiki/HowToEncryptWithJava

最佳答案

首先要检查的是您使用的字节数。您将 IV、 key 和明文列为字符。这些字符将使用某种编码转换为字节。检查字节的样子，而不是字符。您需要逐字节列出两台机器上的所有内容并进行比较。或者，准确指定您将在每台机器上使用的转换。机器默认值很可能不同。

一旦知道输入字节相同，我们就可以寻找其他问题。

作为次要点，一般使用padding比较好，比如PKCS#7；这样你就不必让你的消息适合密码的 block 大小。

关于java - iPhone和Android的加密方式，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/13159847/