ADFS : Claims rules and regex

I answer a lot of claims rules questions over on the forum:

Claims based access platform (CBA), code-named Geneva

and a lot of them concern regex.

One of the recent ones concerned:

"This works fine. I want to filter groups that are included in outgoing claim to just groups which start with string "SG". So I wrote custom ADFS rule:

c:[Type == "http://schemas.xmlsoap.org/claims/Group", Value =~
"(?i) ^SG*"]
=> issue(claim = c);"

There's a number of tools to check the regex. I tend to use Expresso.

But then I came across an article which showed an easy way to check this in PowerShell.

PS C:\> "SG1234" -match '(?i)^SG*'
True
PS C:\> "abcSG1234" -match '(?i)^SG*'
False
PS C:\> "SG1234" -match '(?i)^SG.'
True
PS C:\> "SG" -match '(?i)^SG.'
False
PS C:\> "SG" -match '(?i)^SG'
True


 ... and you can see some of the other strings I played around with.

Neat!

Enjoy!