We strongly recommend that service providers confirm all communications that take place with Auðkenni's system.
What do I need to confirm?
This can be roughly divided into two:
Verify that the responses are coming from our servers
Confirm signatures and certificates that are in the responses from Auðkenni’s system
To verify that responses are coming from our servers
To verify that the responses are coming from us, there is a so-called ".wellknown" endpoint that you can use to access information. Inside this endpoint, you can find the "jwks_uri" which is a path to the keys that can be used to verify that the response you receive is from our server.
An example of a .wellknown endpoint (replace "pfzww" with your Base URL):
https://pfzww.audkenni.is/sso/oauth2/realms/root/realms/audkenni/.well-known/openid-configuration
This endpoint will give you a response similar to this:
{"request_parameter_supported":true,"introspection_signing_alg_values_supported":["ES384","PS384","ES256","PS256","PS512","EdDSA","HS512","RS384","RS256","RS512","HS256","ES512","HS384"],"introspection_encryption_alg_values_supported":["RSA-OAEP-256","ECDH-ES+A256KW","A128KW","A192KW","RSA-OAEP","ECDH-ES+A192KW","A256KW","ECDH-ES","ECDH-ES+A128KW","dir"],"claims_parameter_supported":false,"introspection_endpoint":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/introspect","check_session_iframe":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/connect/checkSession","scopes_supported":["signature","openid","profile"],"backchannel_logout_supported":true,"issuer":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni","id_token_encryption_enc_values_supported":["A256GCM","A128GCM","A256CBC-HS512","A128CBC-HS256","A192CBC-HS384","A192GCM"],"acr_values_supported":["nexus","sim-auth","app-auth","app-certificate-choice","nexus-sign","default","newcards-auth","app-sign","app-sign-with-certificate","apidefault","sim-sign","sim","sim-sign-pkcs1","oldcards-auth"],"userinfo_encryption_enc_values_supported":["A256GCM","A128CBC-HS256","A192CBC-HS384","A192GCM","A128GCM","A256CBC-HS512"],"authorization_endpoint":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/authorize","request_object_encryption_enc_values_supported":["A128GCM","A256GCM","A192CBC-HS384","A256CBC-HS512","A128CBC-HS256","A192GCM"],"introspection_encryption_enc_values_supported":["A128CBC-HS256","A192CBC-HS384","A256GCM","A256CBC-HS512","A128GCM","A192GCM"],"rcs_request_encryption_alg_values_supported":["RSA1_5","dir","A192KW","RSA-OAEP-256","RSA-OAEP","A256KW","A128KW"],"claims_supported":["profile","name","locale"],"userinfo_signing_alg_values_supported":["ES256","HS512","ES512","HS384","RS256","ES384","HS256"],"rcs_request_signing_alg_values_supported":["RS512","PS384","PS256","HS256","HS384","ES512","RS256","RS384","HS512","ES384","ES256","PS512"],"token_endpoint_auth_methods_supported":["client_secret_post","private_key_jwt","self_signed_tls_client_auth","tls_client_auth","none","client_secret_basic"],"tls_client_certificate_bound_access_tokens":true,"backchannel_logout_session_supported":true,"token_endpoint":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/access_token","response_types_supported":["code token id_token","code","code id_token","device_code","id_token","code token","none","token","token id_token"],"revocation_endpoint_auth_methods_supported":["client_secret_post","private_key_jwt","self_signed_tls_client_auth","tls_client_auth","none","client_secret_basic"],"request_uri_parameter_supported":true,"rcs_response_encryption_enc_values_supported":["A256CBC-HS512","A192CBC-HS384","A256GCM","A128GCM","A192GCM","A128CBC-HS256"],"userinfo_encryption_alg_values_supported":["RSA-OAEP","dir","A256KW","RSA-OAEP-256","A128KW","A192KW","RSA1_5"],"grant_types_supported":["refresh_token","authorization_code","urn:openid:params:grant-type:ciba","urn:ietf:params:oauth:grant-type:uma-ticket","idm_delegation","urn:ietf:params:oauth:grant-type:jwt-bearer"],"end_session_endpoint":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/connect/endSession","rcs_request_encryption_enc_values_supported":["A256GCM","A256CBC-HS512","A192GCM","A128CBC-HS256","A128GCM","A192CBC-HS384"],"revocation_endpoint":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/token/revoke","version":"3.0","rcs_response_encryption_alg_values_supported":["dir","A256KW","RSA-OAEP-256","A128KW","A192KW","RSA-OAEP","RSA1_5"],"userinfo_endpoint":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/userinfo","token_endpoint_auth_signing_alg_values_supported":["RS512","RS384","RS256","ES512","HS256","HS384","PS512","ES384","PS256","ES256","HS512","PS384"],"require_request_uri_registration":true,"code_challenge_methods_supported":["plain","S256"],"id_token_encryption_alg_values_supported":["A128KW","A192KW","RSA-OAEP-256","RSA-OAEP","A256KW","RSA1_5","dir"],"jwks_uri":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/connect/jwk_uri","subject_types_supported":["public"],"id_token_signing_alg_values_supported":["RS384","RS256","PS512","ES512","HS384","HS256","PS256","ES256","PS384","ES384","RS512","HS512"],"registration_endpoint":"https://pfzww.audkenni.is:443/sso/oauth2/realms/root/realms/audkenni/register","request_object_signing_alg_values_supported":["RS256","ES512","PS512","RS384","HS512","ES256","ES384","HS256","HS384","PS384","RS512","PS256"],"request_object_encryption_alg_values_supported":["RSA-OAEP-256","A256KW","RSA-OAEP","RSA1_5","dir","A128KW","A192KW"],"rcs_response_signing_alg_values_supported":["PS256","ES384","RS512","ES256","HS512","PS384","RS256","ES512","PS512","HS384","HS256","RS384"]}
An example of a jwks_uri from the response (replace Base URL):
https://pfzww.audkenni.is/sso/oauth2/realms/root/realms/audkenni/connect/jwk_uri
This endpoint will give you a response similar to this:
{"keys":[{"kty":"RSA","kid":"K4h0TN2QBJYOVXAx3gYfn6nlajU=","use":"sig","x5t":"1hxzBQ9NTcb1VVUvWQAyenjNp9Y","x5c":["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"],"n":"iDd-Z55EvAwpSgd15AH3G-gvLXOgF-3NQKt3DxYLzWsNmwdMb9-qCwTeEpZQ32zPOjuG6hyhHYlEQC-HaOIirR9cNDHL2G4QJr3U6WKz-s3ne42vOlL0CfygwRaGTUtRm0uBvzHGtYOicH1fYyGhqxUI--SBlk8EhjawZNLvdFtno3ffh36ACIAv5hj45LUCzFNdnzZi5RQTniAPesdg9TrLXAuuqKUHPU06KyH38BbqHQAdbougRJoXhmUlShBBakoJH5-F4d1IM-HJu1U29fvYXmh8bLvuhWM0HfWSqZjFPoPvnYjEJSWcUMaxrVabnb5VZYdYkvuAgCt1Bi3IJw","e":"AQAB"},{"kty":"RSA","kid":"NefWEBJqU24exUROW9FARwKaztg=","use":"enc","x5t":"-7rTDZk0bOt3bIjnLfVDSOZjIzw","x5c":["MIIC5zCCAc+gAwIBAgIILsOY4ny5r+IwDQYJKoZIhvcNAQELBQAwIjERMA8GA1UEChMIQXVka2VubmkxDTALBgNVBAMTBHRlc3QwHhcNMjExMTE5MDg0MDI1WhcNMjQxMTA4MDg0MDI1WjAiMREwDwYDVQQKEwhBdWRrZW5uaTENMAsGA1UEAxMEdGVzdDCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAOq/HN4UV98QMsRhodA0EX7ErX9lMyhznM83bxB8pTtiPUTCjw6omSp/RMBXhIc2gmGEqLyVstFqH+t7d6rByE7idRbQK4GX9R2xmpkxSv4tn19jFHszUWeGmjwoun6EQ/Rs03PJBEGhUhrRD3jrEgSM7dbORHmMTmhvXPNxIVaL+4Gk7AmXRF0vMq6M6g4ab1/sCiMIEH4Vhj2taYSW9jxWK0tgRYz+IOK0VbZ19kLjFVajIzqYxIY86KD/poXn/5BUHxP/xbrhTK+wIO9nuDCR6iCgqoQaA3P0qt/Okps5wlU0vsg/rW26CsbQEhbKnxOEu13wnmaoEqcsVa392CMCAwEAAaMhMB8wHQYDVR0OBBYEFP9TPPHzuc5aJoFE1yJOUwuoeECuMA0GCSqGSIb3DQEBCwUAA4IBAQDIEQD5ucXUIUInzkQPb80B6wKD3s7TWXeZ4IWQn8h5zw/r5pRUEZx+EwtiDGMoCQWsJ4YtQ9KH4MAd37ZqYIJDN+7ZkaLp5FSdcVtBXlqFg3EKDDkrV/hY5YA+JVxJ/KJ5WyRHCe72No1r3+lxFjQti5xf8Uo1WfZbt0nYkZZuO/11mfCiUvUY6bFs6oNVbL886lF9XvPoxkx+637V2GPjlGgmrwaaP19bYIjxMQMsUrZYqhFfIehOPPKkRRjYrcjdSfxDjCygoTUMTYrDb4lEzHimo8BiybEP4qJXhfjYdGTCfvwnnj0nCX8j8exASAJOZJLXNGiXWf15d71XPaHY"],"n":"6r8c3hRX3xAyxGGh0DQRfsStf2UzKHOczzdvEHylO2I9RMKPDqiZKn9EwFeEhzaCYYSovJWy0Wof63t3qsHITuJ1FtArgZf1HbGamTFK_i2fX2MUezNRZ4aaPCi6foRD9GzTc8kEQaFSGtEPeOsSBIzt1s5EeYxOaG9c83EhVov7gaTsCZdEXS8yrozqDhpvX-wKIwgQfhWGPa1phJb2PFYrS2BFjP4g4rRVtnX2QuMVVqMjOpjEhjzooP-mhef_kFQfE__FuuFMr7Ag72e4MJHqIKCqhBoDc_Sq386SmznCVTS-yD-tbboKxtASFsqfE4S7XfCeZqgSpyxVrf3YIw","e":"AQAB"},{"kty":"EC","kid":"T4HpP8SlCjLmEazbTNZ8j1/IIvk=","use":"sig","x5t":"BIiX_2w5Io0PAS3oDURSbDVK_f8","x5c":["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"],"x":"AL61OI-V235LLChS7mymcSOmgkX96TR_xm-Fv7UqTe6MrcLUqR2eSN1G-P_pGisQJ5QZHlFg0SuBUYew5mGhc8hN","y":"ASkuS9BtSzLBCZdcHmkn-FW7dLK1hTOrKnizrSTTREWnUO4aGYnRHcPl6vyxPEgXZ0IQbjjT-jd3mDdydCwS9Caf","crv":"P-521"},{"kty":"EC","kid":"HmusVH9OnoQd7evfLa+CyKihFoo=","use":"sig","x5t":"-30DTwdwKD8qMHoEd7B38jj8OMI","x5c":["MIIBYTCCAQagAwIBAgIJAJ/bjPetKN9JMAwGCCqGSM49BAMCBQAwIzERMA8GA1UEChMIQXVka2VubmkxDjAMBgNVBAMTBWVzMjU2MB4XDTIxMTExOTA4NDAyMVoXDTI0MTEwODA4NDAyMVowIzERMA8GA1UEChMIQXVka2VubmkxDjAMBgNVBAMTBWVzMjU2MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEv0me73TLfyMb1NVvKsPUG3p36pc02R+5GNZPkMrgqWzJRLt27vDN/m1SUKMTmlbTjiliyNnsnbxfLLz4ffhnO6MhMB8wHQYDVR0OBBYEFD+Ibr3+RmDGlBW+KKHjW3Ijhd94MAwGCCqGSM49BAMCBQADRwAwRAIgKIBV7lRgm5tbwVf9zsoZnBBsSQ+DNims6FqyyDhRZioCIBBhDp5xVit8sqduqmZbYV/gLyPHKdR9f+M/a9i0KkmM"],"x":"v0me73TLfyMb1NVvKsPUG3p36pc02R-5GNZPkMrgqWw","y":"yUS7du7wzf5tUlCjE5pW044pYsjZ7J28Xyy8-H34Zzs","crv":"P-256"},{"kty":"EC","kid":"CbJYmrtlpLrMno/Z+n5b7FmBmKI=","use":"sig","x5t":"de4wUDcaPEccuV5iqJNPWd36p4M","x5c":["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"],"x":"Dx3joLZ-7jsGOEXxSa__8ILYL4hDigkUZXahlPaCgkD6QeRLdoCiN_y8_su8cdod","y":"EK0jeha6KCWTM8kQAR2MHy_n0eNP5tW36VBajvVw-xDvqAGKfO3PHovNLgScrOyj","crv":"P-384"}]}
This response hold keys you can use to verify the access_token and id_token from our system.
To verify the signatures
You receive PKCS7 or PKCS1 signature, depending on which method you are using.
To verify PKCS7 signature
There are ready-made tools available for most programming languages that can be used to verify PKCS7 signatures. Below is a small code example in C# that hopefully makes it clearer:
private bool validateSignPKCS7(string toValidate)
{
byte[] fromCMSString = null;
SignedCms cms = null;
try
{
fromCMSString = Convert.FromBase64String(toValidate);
cms = new SignedCms();
cms.Decode(fromCMSString);
cms.CheckSignature(true);
}
catch (Exception u)
{
return false;
}
return true;
}
The PKCS7 signature should contain the certificate of the person who is authenticating/signing. That certificate needs to be verified.
To verify PKCS1 signature
private bool validatePKCS1Signature(string signatureFromAudkenni, string hashStringFromAuthenticationRequest, string certFromAudkenni)
{
byte[] orgHash = null;
byte[] signedHash = null;
byte[] certBytes = null;
X509Certificate2 certificate = null;
try
{
orgHash = Convert.FromBase64String(hashStringFromAuthenticationRequest);
signedHash = Convert.FromBase64String(signatureFromAudkenni);
certBytes = Convert.FromBase64String(certFromAudkenni);
certificate = new X509Certificate2(certBytes);
RSA key = (RSA)certificate.PublicKey.Key;
RSAPKCS1SignatureDeformatter formatter = new RSAPKCS1SignatureDeformatter(key);
formatter.SetHashAlgorithm("SHA512");
var result = formatter.VerifySignature(orgHash, signedHash);
return result;
}
catch (CryptographicException e)
{
return false;
}
}