SSL for IOS 9. Which SSL certificate registrar to choose?

Question

Digital certificates

You can sign the certificate yourself or you still need to buy it, for example, COMODO Positive SSL
Since on your own certificate it gives this error NSURLSession/NSURLConnection HTTP load failed (kCFStreamErrorDomainSSL, -9802)
And when I access the link https://mail.ru , the page turns out well.
What is the best SSL registrar?

Answer 1

There is no such thing as a registrar. There is a concept of Authorization Center (Certificate Authority or CA). They all do essentially the same thing and the difference in price is brand awareness + marketing. And nothing more.
Therefore, you were rightly advised Comodo - an affordable and good option.
Buying directly from the Authorization Center is expensive. For wholesale buyers / distributors, they give great discounts and buy from resellers cheaper.
In Russia, the most budgetary and direct option https://firstssl.ru

Answer 2

Comodo
price/quality