iOS 过期的证书怎么处理

iOS如果提示XX证书过期，可以参考下面的帮助，有些必须要及时生成，有些可以晚点。
Certificates

Apple
Developer Program membership is required to request, download, and use
signing certificates issued by Apple. You must also be the Team Agent or
an admin of your development team to request distribution certificates
used for submitting apps to the App Store or Mac App Store. For more
information on how to use signing certificates, review the App
Distribution Guide.
In most cases, Xcode is the preferred method to request and install digital certificates for iOS
and OS X. However, to request certificates for the Apple Push
Notification service, Passbook, Mobile Device Management (MDM), and
Safari extensions, you will need to request and download them from
Certificates, Identifiers & Profiles in your account on the
developer website.
Expired or Revoked Certificates
Apple Push Notification Service Certificate
You can no longer send push notifications to your app.
Pass Type ID Certificate (Passbook)
If
your certificate expires, passes that are already installed on users'
devices will continue to function normally. However, you will no longer
be able to sign new passes or send updates to existing passes. If your
certificate has been revoked, your passes will no longer function
properly.
iOS Distribution Certificate (App Store)
If
your Apple Developer Program membership is valid, your existing apps on
the App Store will not be affected. However, you will no longer be able
to submit new apps or updates to the App Store.
iOS Distribution Certificate (in-house, internal use apps)
Users
will no longer be able to run apps that have been signed with this
certificate. You must distribute a new version of your app that is
signed with a new certificate.
Mac App Distribution Certificate and Mac Installer Distribution Certificate (Mac App Store)
If
your Apple Developer Program membership is valid, your existing apps on
the Mac App Store will not be affected. However, you will no longer be
able to submit new apps or updates to the Mac App Store.
Developer ID Application Certificate and Developer ID Installer Certificate (Mac applications)
If
your certificate expires, users can still download, install, and run
versions of your Mac applications that were signed with this
certificate. However, you will need a new certificate to sign updates
and new applications. If your certificate has been revoked, users will
no longer be able to install applications that have been signed with
this certificate.
Apple Worldwide Developer Relations Certification Intermediate Certificate
The
Apple Worldwide Developer Relations Certificate Authority issues
certificates used by developers for signing third party apps and Safari
Extensions, and for using Apple Wallet and Apple Push Notification
services. We've issued a renewed certificate that must be included when
signing all new Apple Wallet Passes, Apple Push Notifications, and
Safari Extensions starting February 14, 2016. Read more.
Note:
Apple can revoke digital certificates at any time at its sole
discretion. For more information, read the Apple Developer Program
license agreements in your account on the developer website.
Compromised Certificates
If
you suspect that your Pass Type ID certificate or Developer ID
certificate and private key have been compromised, and would like to
request revocation of the certificate, send an email to
product-security@apple.com. You can continue to develop and distribute
passes by requesting an additional certificate from your account on the
developer website.
I received an error message saying, "Xcode
could not find a valid private-key/certificate pair for this profile in
your keychain."
This error message indicates that your system's
Keychain is missing either the public or private key for the certificate
you are using to sign your application.
This often happens when
you are trying to sign and build your application from a different
system than the one you originally used to request your code signing
certificate. It can also happen if your certificate has expired or has
been revoked. Ensure that your app's provisioning profile contains a
valid code signing certificate, and that your system's Keychain contains
that certificate, the private key originally used to generate that
certificate, and the WWDR Intermediate Certificate.
For instructions on how to resolve this error, review the Code Signing support page.
What happens to my Developer ID–signed applications if my Apple Developer Program membership expires?
If
your membership expires, users can still download, install, and run
your Developer ID–signed applications. However, once your Developer ID
certificate expires, you must be an Apple Developer Program member to
get new Developer ID certificates to sign updates and new applications.

1、对于过期的证书，直接删掉就可以了，如果还需要使用，就需要重新下载，证书不能更新。
2、一些证书下载的时候需要特殊账户，比如：ios开发时，如果想要在真机上编译就需要下载开发证书，这个证书需要开发者账户（99美刀/年）才能下载使用，普通用户登录是不能编译的。