Friday, March 08, 2019

AD : Domain Controller password policy

Every now and then you get an error:

"Unable to update the password. The value provided for the new password does not meet the length, complexity, or history requirements of the domain."

So you need to find out the allowed length in the password policy.

An easy way to do this is to run:


Other reasons for this message are that you have already changed your password in the last 24 hours or that you have reused a password that you used in the last 24 passwords.


Wednesday, February 27, 2019

IdentityServer: IResourceOwnerPasswordValidator

I was looking at idsrv4 and how to integrate it with a custom user store. In this case it was SQL Server.

idsrv4 uses .NET Core 2.2 but a lot of the samples I found were for earlier versions of .Net Core.

Some of the samples used IUserService but I couldn't find that.

So Mr Google to the rescue.


"In IdentityServer4. IUserService is not available anymore, now you have to use IResourceOwnerPasswordValidator to do the authentication and to use IProfileService to get the claims."

The problem I have with this is that Resource Owner Password is not just a random method name. It's the name of an OAuth flow! Most people don't realise this.

My client used implicit flow. Using IResourceOwnerPasswordValidator makes no sense.

So  you can just use a controller to authenticate the user like the AccountController.


Tuesday, January 29, 2019

Azure : Web API - The requested resource does not support http method 'GET'

I was running a web API on Azure and doing a POST.

The full error is:

    "Message": "The requested resource does not support http method 'GET'."

That's weird because the method is decorated with  [HttpPost] and I was doing a POST.

Then I noticed that I was calling Azure with a http connection.

Changing to https fixed the issue.


Thursday, December 06, 2018

ADFS : MSIS7042 - The same client browser session has made '6' requests

The full error message is:

Exception details: Microsoft.IdentityServer.Web.InvalidRequestException: MSIS7042: The same client browser session has made '6' requests in the last '7' seconds. Contact your administrator for details.

There are many causes for this; one being the "missing /" on the identifier.

I found one recently where I was running an ASP.NET MVC application inside VS that was authenticated via ADFS. This used the OWIN WS-Fed middleware.

I couldn't authenticate because of this error.

ADFS will only accept https connections so the RP was configured with a:



But on VS, inside "Properties / Web", I noticed that the URL was:


Setting this to https fixed the problem.

Go figure.

I found a similar solution here.


Friday, November 23, 2018

Azure AD : Getting the UPN

I've been playing around with the custom SAML connection in Azure AD and the "claims transformations"  that you can do e.g. tolower.

My interest was Guest accounts.

The user screens don't show the UPN so I needed to do this with PowerShell.

connect-azuread -tenant tenantname

Get-AzureADUser -Filter "userType eq 'Guest'" -All $true | select Displa

This displays:

DisplayName                    : Joe
UserPrincipalName              :
Mail                           :
Department                     :
UserType                       : Guest
CreationType                   : Invitation
RefreshTokensValidFromDateTime : 21/11/2018 11:13:58 p.m.
AccountEnabled                 : True

Or if you wanted the top 10:

Get-AzureADUser -Filter "userType eq 'Guest'" -Top 10 | select DisplayNa

Or complex filter:

Get-AzureADUser -Filter "mail eq '' and userType eq '

If you want to see the full list of Azure AD attributes with the complete schema, use:

Get-AzureADUser  -All $true | fl > allad.txt


Wednesday, October 24, 2018

Azure B2C : Calling a web API from Azure AD B2C using data types

There is a good overview here.

In terms of the data types that you can pass, these can be:
  • boolean
  • date
  • dateTime
  • int
  • long
  • string
  • stringCollection
  • alternativeSecurityIdCollection

The above is the XML to define some of the claim types.

In terms of the JWT returned, the claims look like:


Tuesday, September 11, 2018

Monday, August 27, 2018

stackoverflow : Top 1%

Finally got there:

There are over 9 million users on stackoverflow and currently I'm sitting at:

Now it gets into the decimals e.g. top 0.5 %


Friday, August 24, 2018

Misc : My audience

Just out of interest, my audience as reported by Blogger.

Strange that Google has "Unknown Region"?

Chrome is way ahead on the browsers and Windows is way ahead on the OS.

Would have thought the iPad figure would be higher but maybe iPad users have no interest in Identity :-)


C# : Invalid URI

The full message is:

"Invalid URI : The hostname could not be parsed".

I get this using the URIBuilder class.

Since it was complaining about the hostname I checked the DNS, I checked that I could ping it, I tried the IP address etc. etc.

Eventually worked out that it was because the password contained special characters.

You are apparently supposed to URL encode them.

Just changed the password to use letters and numbers and all was well.

Somewhat misleading error message :-)


Friday, July 13, 2018

stackoverflow : Answered 1,000 questions

Achievement unlocked!

Most of these are in the Identity space and of course the problem is that in order to answer a question, someone has to ask it first.

It is somewhat of a niche category. I've been on stackoverflow for 9 years and 10 months (at time of writing) so it's taken a while to get here.

Looking at the tags e.g. ADFS:

What's also interesting about this is the other contributors.

Just calling out some of them:

Eugenio Pace and Matias Woloski are the founders of Auth0 and vibronet has recently joined them.

leastprivilege is one of the people behind identityserver.

Across the other tags:

I guess now I need to identify my next achievement!

And onto the next 1,000!


Thursday, July 12, 2018

Certificates : Displaying errors

Quite often, you can't connect to an SSL site because .NET will tell you that the certificate is invalid.

This openssl command shows you the certificate errors:

openssl s_client -connect|openssl x509 -text

The output looks like:

depth=2 CN = Company Root CA
verify error:num=19:self signed certificate in certificate chain
        Version: 3 (0x2)
        Serial Number:


It also checks the intermediate and root CA certificate validation chain.