在Windows下請支援CNG加密後端

[NagisaEfi]

在Windows下請支援CNG（CryptNextGen）加密後端。在Windows筆電下而且電池供電時，使用Shadowsocks-rust比較耗電。因為libsodium運行於Ring 3，且不支持硬件加速。而CNG集成於Windows，支持硬件加速。

如果檢測到Windows 10/11（Windows版本號10.x），自動使用CNG加密後端；否則，使用libsodium加密後端。

Windows下的Edge瀏覽器就用了CNG。

[database64128]

First of all, shadowsocks-rust does not use libsodium. It uses ring, which takes advantage of supported CPU instruction for the best performance. For example, it uses the {V}AES/{V}PCLMULQDQ instructions on x86 for AES-GCM.

Secondly, you are implying that running crypto operations inside the kernel is more efficient, which is incorrect for userspace programs. Turning each crypto operation into a syscall only adds extra overhead. Famously the Linux kernel crypto API is rarely used by userspace programs. Calling the BCrypt* functions you mentioned also runs the crypto operations in userspace.