Getting Error while trying to access nextcloud through sso - single-sign-on

Question

I have problems with SAMLRequest not being authenticated by nextcloud
<samlp:Response ID="_7b0ef094-ae04-4d2c-a7d1-e9d5e698c278"
Version="2.0"
IssueInstant="2019-05-28T12:19:07.704Z"
Destination="https://192.168.1.136/index.php/apps/user_saml/saml/acs"
Consent="urn:oasis:names:tc:SAML:2.0:consent:unspecified"
xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol">
<Issuer xmlns="urn:oasis:names:tc:SAML:2.0:assertion">http://WindowsServer19.server.net/adfs/services/trust</Issuer>
<samlp:Status>
<samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success" /></samlp:Status>
<Assertion ID="_3acf9e24-2f34-47bf-82fb-97f6d11ab652"
IssueInstant="2019-05-28T12:19:07.703Z"
Version="2.0"
xmlns="urn:oasis:names:tc:SAML:2.0:assertion">
<Issuer>http://WindowsServer19.server.net/adfs/services/trust</Issuer>
<ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
<ds:SignedInfo>
<ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" />
<ds:SignatureMethod Algorithm="http://www.w3.org/2000/09/xmldsig#rsa-sha1" />
<ds:Reference URI="#_3acf9e24-2f34-47bf-82fb-97f6d11ab652">
<ds:Transforms>
<ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature" />
<ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#" /></ds:Transforms>
<ds:DigestMethod Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
<ds:DigestValue>0frZvK2y9o8WTDfpB3rBlK+82W4=</ds:DigestValue>
</ds:Reference>
</ds:SignedInfo>
<ds:SignatureValue>
s4NAgv4ucV5xM6Ig+GsNunpNo5whkJljUec9KtNh00UbRZJ3q2KdzNQ3ZxhpvYudTDqlgzwnenaPmZIcpmgzuqaIiHTStBWUgafZDljZ4/WnQ8SRslMBgRNtuh3NU8qh+0Hgr3k+ngZc1YvlACy+sPeoBxZoFKTC+cwXVeezdlTnPW+IbZ2T1xeLmjz42oelqrnGbsnu6btNgTHzij302YCsbnlKe6wAEw9CvjFCtWPW1dV9iL6FLYkJfPporG9D7FkW+nZoYa8SHns8VRFM97sBKSBcX/csneJiX+7b+hZttw+MPsXmXBgXiU8D0boRjqKByv51fhlhLpKl3HRZZg==
</ds:SignatureValue>
<KeyInfo
xmlns="http://www.w3.org/2000/09/xmldsig#">
<ds:X509Data>
<ds:X509Certificate>
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
</ds:X509Certificate>
</ds:X509Data>
</KeyInfo>
</ds:Signature>
<Subject>
<NameID>Administrator</NameID>
<SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer">
<SubjectConfirmationData NotOnOrAfter="2019-05-28T12:24:07.704Z"
Recipient="https://192.168.1.136/index.php/apps/user_saml/saml/acs" />
</SubjectConfirmation>
</Subject>
<Conditions NotBefore="2019-05-28T12:19:07.702Z"
NotOnOrAfter="2019-05-28T13:19:07.702Z">
<AudienceRestriction>
<Audience>https://192.168.1.136/index.php/apps/user_saml/saml/metadata</Audience>
</AudienceRestriction>
</Conditions>
<AttributeStatement>
<Attribute Name="http://schemas.microsoft.com/2012/12/certificatecontext/field/issuername">
<AttributeValue>Aleksandar</AttributeValue>
</Attribute>
<Attribute Name="http://schemas.xmlsoap.org/ws/2005/05/identity/claims/surname">
<AttributeValue>Andric</AttributeValue>
</Attribute>
<Attribute Name="sAMAccountName">
<AttributeValue>Administrator</AttributeValue>
</Attribute>
</AttributeStatement>
<AuthnStatement AuthnInstant="2019-05-28T12:19:07.675Z"
SessionIndex="_3acf9e24-2f34-47bf-82fb-97f6d11ab652">
<AuthnContext>
<AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:PasswordProtectedTransport</AuthnContextClassRef>
</AuthnContext>
</AuthnStatement>
</Assertion>
</samlp:Response>
I am using ADFS as Identity provider and nextcloud as Service Provider, and I can't make them work for 2 weeks. When i click on the sso & saml button on nextcloud http://prntscr.com/nuevag this error occurs and after deleting SAMLRequest and RelayState query parameters and deleting cookies login page is shown http://prntscr.com/nuez9s and after signing in 'Account not provisioned' error appears http://prntscr.com/nuf01w. Log files show http://prntscr.com/nuf0qj but in ADFS, URL is set with https:// http://prntscr.com/nuf11w. Do you have any idea how to make this work. Thank you very much!

Answer 1

You need to trace the SAML request. Either ADFS does not know the Issuer of the SAML AuthnRequest or it may not be able to verify the signature of SAML AuthnRequest (if it was digitally signed).
IdP initiated SSO as shown in https://prnt.sc/nuez9s is a totally different flow, where the IdP only sends a SAML response, there is no SAML AuthnRequest.
ADFS event log would actually show (also sometimes in a somewhat cryptic way) why the SAML AuthnRequest could not be handled.