List of trusted root certificates available in IOS
The iOS trusted certificate store contains trusted root certificates that are preinstalled with iOS.
About trusts and certificates
Each IOS trusted certificate store listed below contains three types of certificates:
- A "trusted" certificate is used to establish a chain of trust to verify other certificates that are signed by a trusted root certificate; For example, to establish a secure connection to a Web server. IT administrators do not need to provide these trusted root certificates when creating an IOS configuration profile.
- The "Always ask" certificate is not trusted, but is not blocked. When you use either of these certificates, you are prompted to choose whether to trust this certificate.
- A "blocked" certificate is considered to be compromised and will never be trusted again.
https://support.apple.com/zh-cn/HT204132
List of trusted root certificates available in IOS