OC 與Java都兼容的AES加密方式

問題

最近公司寫個項目，遇到的問題，在此記錄一下。後端和安卓端用的都是java，加密過程很順利，iOS端AES加密就沒那麼順利，我加解密後的值和後端不一致，導致無法正確解密。我一度認爲是我的代碼出現了問題，後來和後端一起調試，發現只有AES/CBC這種加密模式和java是兼容的，下面貼出來具體代碼：（已驗證可放心使用）

加密

//(key和iv向量這裏是16位的) 這裏是CBC加密模式，安全性更高
+ (NSString *)encryptAES128CBCData:(NSData *)data key:(NSString *)key gIv:(NSString *)Iv {
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    
    char ivPtr[kCCKeySizeAES256+1];
    memset(ivPtr, 0, sizeof(ivPtr));
    [Iv getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
    
    NSUInteger dataLength = [data length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCEncrypt,
                                          kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding,
                                          keyPtr,
                                          kCCBlockSizeAES128,
                                          ivPtr,
                                          [data bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
        NSData *mydata = [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
        NSString* strret = [mydata base64EncodedStringWithOptions:0];
        return strret;
    }
    free(buffer);
    return nil;
}

解密

+ (NSString *)decryptAESCBCData:(NSData *)encrptData key:(NSString *)key  iv:(NSString *)vector {
    char keyPtr[kCCKeySizeAES256+1];
    bzero(keyPtr, sizeof(keyPtr));
    [key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
    
    char ivPtr[kCCKeySizeAES256+1];
    memset(ivPtr, 0, sizeof(ivPtr));
    [enVector getCString:ivPtr maxLength:sizeof(ivPtr) encoding:NSUTF8StringEncoding];
    
    NSUInteger dataLength = [encrptData length];
    size_t bufferSize = dataLength + kCCBlockSizeAES128;
    void *buffer = malloc(bufferSize);
    size_t numBytesEncrypted = 0;
    CCCryptorStatus cryptStatus = CCCrypt(kCCDecrypt,
                                          kCCAlgorithmAES128,
                                          kCCOptionPKCS7Padding,
                                          keyPtr,
                                          kCCBlockSizeAES128,
                                          ivPtr,
                                          [encrptData bytes],
                                          dataLength,
                                          buffer,
                                          bufferSize,
                                          &numBytesEncrypted);
    if (cryptStatus == kCCSuccess) {
            NSData *resultData = [NSData dataWithBytesNoCopy:buffer length:numBytesEncrypted];
            
            return [[NSString alloc] initWithData:resultData encoding:NSUTF8StringEncoding];
        }
        free(buffer);
        return nil;
}

如果把參數kCCOptionPKCS7Padding變成kCCOptionECBMode | kCCOptionPKCS7Padding,就是ECB模式，這種模式不需要vector向量，但是和JAVA算出來不一致，如有其他方式，請留言。