Certificate
The certificates your project uses for secure exchange - AS2 partners, signed payloads, and anything else that needs one.
Uploading
Create, then choose the file. Accepted formats are .cer, .crt, .pem,
.pfx, .p12 and .der.
The file's name becomes the X509 alias and its extension becomes the type, so name the file the way you want to find the certificate later.
The list
ID, Serial Number, Type, Signature Algorithm, X509 Alias, Valid From, Valid To and the audit dates. The date columns filter by day, which is the quickest way to find what is expiring.
Valid To is the column to watch - an expired certificate fails at exchange time, not at upload time.
Replacing one
Edit replaces the file on an existing certificate, keeping its place. Use this to renew rather than deleting and re-adding, so nothing pointing at it breaks.