[IMPROVE] Add decoding for commonName (cn) and displayName attributes for SAML

[pkolmann]

I want to create users via SAML. Currently the SAML IDP sends the Attributes urn:oid-encoded. This patch adds the decoding for commonName (cn) and displayName attributes.

Secondly it adds the displayName as a possibility for the name of the new user.

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you all sign our Contributor License Agreement before we can accept your contribution.
3 out of 4 committers have signed the CLA.

✅ pkolmann
✅ sampaiodiego
✅ engelgabriel
❌ Rocket Chat

---

Rocket Chat seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[pkolmann]

I have signed the CLA already but it still shows as unsigned :(
and tried to finish the circleci build, but it's on hold and if I click on approve, nothing happens.

Can anyone suggest any solutions? Thanks

[pkolmann]

@MarcosSpessatto could you please review my changes and help me get them merged. Thanks

[pkolmann]

@Hudell do you have any hint for me, if this change could be merged?

[rodrigok]

@pkolmann can you fix the conflicts?

[pkolmann]

@rodrigok I fear I f*ed up my branch again... :(

I have an updated patch that applies cleanly to 0.73.1. Can you use this as well?

Maybe someone can tell me, where I did the update of my branch wrong:

git clone git@github.com:pkolmann/Rocket.Chat.git rocketChatGit
cd rocketChatGit/
git remote add upstream git@github.com:RocketChat/Rocket.Chat.git
git merge upstream/master
git push

rocketChat-SAML.diff.txt

[Hudell]

You should use the develop branch instead of master

[pkolmann]

@Hudell thanks for the hint. I managed now to get everything uptodate. Now you should be able to pull.

[pkolmann]

@rodrigok the branch is now in sync and can be merged. Thanks

[engelgabriel]

@sampaiodiego can you review and merge this?