Error: the request specified an assertion consumer service url is not registered in the metadata for the SP

It means your SP metadata dont have correct Assertion Consumer url that client send to IDP

how to get uid when using mod auth mellon for PHP application

 If I add one line to mellon.conf:

MellonUser "uid"

then Apache (or maybe it's Mellon) will populate the $_SERVER['PHP_AUTH_USER'] property that PHP applications need in order to identify a user with the UID from the directory.  That reduces the dependency on headers

forgerock openam error HTTP Status 400 - Error processing AuthnRequest. The receiving entity ID is not valid or not trusted

check your COT or metaAlias   its value might be wrong.

ForgeRocck Logfile information

SSO initiated request type

POST binding
request is in the body

Artifacts Binding
SP send request to IDP, IDP will send HTTP-Artifacts, SP will download artifact from IDP and process it

Http Redirect Binding
Browser Request it is combination to both

OpemAM POST data request flow

Http get will redirect the user to the original request after authentication.

HTTP POST have different flow, original request is in the body of the request that’s why we cant put the original request into goto because OAM  will lose the content of the request. We will still use goto but in this request will not use original request, instead it will point to dummy url and Policy agent will hold the original request. After successful authentican Policy agent will retrive the original cache POST data and Post Form is submitted to browser, browser execute(browser needs to support JavaScript)  self submitted Form and browser will create new POST Request. Now browser have IPlantDirectoryPro cookie.

what cookies are being set up by Forgerock OpenAM

OpenAM set 2 cookies in the browser after the successful user authentication

  "amlbcookie" and  "iPlanetDirectoryPro"