Introduction - If you have any usage issues, please Google them yourself
Recently due to the start of the project of state secret SM2 encryption. Internet is also looking for a long time, but not on the iOS, there are a lot of implementation of OpenSSL based on C language, but because C is white, and the code is a mess, no comments, hang a lot of download points later found. GmSSL implementation of sm2. encountered various pits, there are also other buddy needs in this area, so the realization of my share.