XMLSec should support multiple certificates with the same name

[cc-int3]

I will write a specific use case, but I think the desired outcome can help in other scenarios which I have not thought of.

I have a project to validate SAML assertions/tokens. Primarily the tokens are issued by ADFS. ADFS uses as self-signed certificate (and associated private key) to digitally sign the xml. About a month before the certificate expires, ADFS will generate a new self-signed certificate/key with the exact same subject, new key and new expiration date and add both old and new certificates to the published metatdata.

When reading the metadata, I put both certificates in the xmlsec certificate store, but when verifying a SAML token, xmlsec will only use one cert from the store for verification. If it happens to get the right one, great. However, if it picks the wrong one, the signature validation will fail, despite the proper cert being available it the store. I feel xmlsec should search the store for additional 'same name' certificates and perform the signature check again if another cert is available.

Thank you for your consideration of this issue.

[lsh123]

Thanks, I understand the use case. It is a bit complex on xmlsec side since the code assumes that key is uniquely identified in the keys store. Said that -- it's only software. Let me think about it.

[lsh123]

Want to check something -- is there an option for you to switch from self-signed certificate to a chain?

root cert -> rotating cert

Then you can embed rotating cert into the signature and verify it against root cert.

[cc-int3]

You can use chained certs, but you lose the automatic rollover feature ( doc )

If you don't use the default, automatically generated, self-signed token signing and token decryption certificates, you must renew and configure these certificates manually.

That's probably a feature a lot of my customers don't want to lose.

[lsh123]

Oh well, can you try https://github.com/lsh123/xmlsec/pull/827 to see if it works for you?

[lsh123]

Interestingly, all other crypto libraries except msng / mscrypto already support the same functionality.

[cc-int3]

Thanks, I have to travel overnight, but I'll test in the morning. Thank you for all the work you've done

[cc-int3]

Actually, I already had a test written...works great.

thanks again

[lsh123]

Great, I also have a test but wanted to make sure it works for you real use case. No rush at all -- absolutely not urgent.

[cc-int3]

cool, i'll see if someone in the office can build/deploy a test version while I'm out

[lsh123]

@cc-int3 wanted to check if you got a chance to test this?

[cc-int3]

I have not been able to get the production guys to throw it into a real world test, but my limited testing shows it works. You can close whenever you want. Thank you

On Mon, Jul 29, 2024, 08:39 lsh123 @.***> wrote:

@cc-int3 https://github.com/cc-int3 wanted to check if you got a chance to test this?

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[lsh123]

Thanks!