qmc

function Decoder

解码器构造函数

explicit qqmusic::crypto::Decoder::Decoder (
    std::string && ekey
) 

Parameters:

• ekey 需要传入加密的密钥

---

function decrypt

密钥解密算法

virtual void qqmusic::crypto::Cipher::decrypt (
    qqmusic::utils::buffer & buf,
    size_t offset
) = 0

Parameters:

• buf 待解密的密钥
• offset 偏移量

---

function read2buf

存取待解密数据到 buf_in 中

bool qqmusic::crypto::Decoder::read2buf (
    qqmusic::utils::buffer && buf
) 

Parameters:

• buf 缓冲区（存放未解密的数据）

---

调用示例：

SongInfo song = ...;
if (song.ekey.has_value()) {
     qqmusic::crypto::Decoder decoder(*song.ekey);
     if (read2buf(buf)) {
         if (decoder.decrypt()) {
             std::cout << "decrypt successful" << std::endl;
         }
     }
} else {
     // throw error
}
// then can use `buf_out`