Invalid Credentials when configuring the Legacy Sharepoint Connector for Confluence

Symptoms

When completing the setup steps to connect the Legacy Sharepoint connector to Confluence, we receive an error in the user interface stating the following.

ERROR: Invalid Credentials
Unable to connect to Confluence. Make sure that Confluence is running at https://MyConfluence.com and that the SharePoint Plugin is installed properly (see https://MyConfluence.com/admin/viewplugins.action).

The following appears in the Sharepoint log files:

08/21/2013 13:11:10.65 w3wp.exe (0x2194) 0x18FC	[Atlassian Confluence] WebPartError 1157483920	Unexpected Atlassian.Confluence.SharePoint.WebServices.LicenceCheckFailedException: Unable to connect to Confluence ---> System.Net.WebException: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel. ---> System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure. at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, Exception exception) at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest) at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest) at System.Net.Security.SslState.ProcessReceivedBlob(Byte...	a964hs9c-4456-4325-a4f2-7a3123fa91e

Cause

SharePoint does not trust the certificate being presented by Confluence.

Workaround

Disable SSL for Confluence.

Resolution

Add the Confluence SSL certificate to the trust store for Sharepoint in IIS.

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