iOS和Java中的AES加密

Question

我是这个加密的新手.我正在为android和iOS创建一个应用程序,我必须在服务器端加密(使用AES加密)文件,并在iOS和Android应用程序中在客户端解密.我在互联网上获得代码,为Android和iOS执行AES加密和解密,它们工作正常.服务器端他们正在使用java.但问题是Java加密文件无法被iOS程序解密,即使我得到了相同的文件大小,但文件格式不正确.我发布了下面的代码......

Java加密和解密:

public static byte[] encrypt(byte[] data, byte[] key, byte[] ivs) {
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");

            SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
            byte[] finalIvs = new byte[16];
            int len = ivs.length > 16 ? 16 : ivs.length;
            System.arraycopy(ivs, 0, finalIvs, 0, len);
            IvParameterSpec ivps = new IvParameterSpec(finalIvs);
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivps);
            return cipher.doFinal(data);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    public static byte[] decrypt(byte[] data, byte[] key, byte[] ivs) {
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            SecretKeySpec secretKeySpec = new SecretKeySpec(key, "AES");
            byte[] finalIvs = new byte[16];
            int len = ivs.length > 16 ? 16 : ivs.length;
            System.arraycopy(ivs, 0, finalIvs, 0, len);
            IvParameterSpec ivps = new IvParameterSpec(finalIvs);
            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivps);
            return cipher.doFinal(data);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

用于解密的iOS代码:

- (NSData *) decryptFile:(NSString *)key withData:(NSData *)fileData {

    char keyPtr[kCCKeySizeAES128+1]; 
    bzero(keyPtr, sizeof(keyPtr)); 

    NSString* iv = @"12345678";

    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];

    NSUInteger dataLength = [fileData length];

    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);

    size_t numBytesDecrypted = 0;

    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt, kCCAlgorithmAES128, kCCOptionPKCS7Padding,keyPtr, kCCKeySizeAES128,
                                          iv /* initialization vector (optional) */,
                                          [fileData bytes], dataLength, /* input */
                                          buffer, bufferSize, /* output */
                                          &numBytesDecrypted);

    if (cryptStatus == kCCSuccess) {
        //the returned NSData takes ownership of the buffer and will free it on deallocation
        return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
    }

    free(buffer); //free the buffer;
    return nil;
}

给我任何解决方案或建议解决这个问题

Answer 1

问题在于iv参数.

1)你正在传递NSString*as iv.您可能想要传入实际的字节.

2)根据ivCCCrypt的api文件,长度应为16(在这种情况下).见以下链接:

http://www.opensource.apple.com/source/CommonCrypto/CommonCrypto-36064/CommonCrypto/CommonCryptor.h