CredSSP

CredSSP, or Credential Security Support Provider, is a Microsoft security protocol. It is a security support provider that supports the Credential Security Support Provider interface. CredSSP allows an application to delegate user credentials from the client to the remote server. This is particularly useful for Remote Desktop Services (RDS) and other remote administration tasks where the user needs to authenticate to a server using their own credentials, but the connection itself is established through an intermediary.

The primary function of CredSSP is to securely transmit the user's credentials from the client machine to the target server. This is achieved through a multi-layered authentication process. First, the client authenticates to the server. If successful, the client then encrypts the user's credentials and sends them to the server. The server decrypts these credentials and uses them to authenticate the user to the target resource or service. This prevents the user from having to re-enter their credentials on the remote server.

CredSSP is implemented as a Security Support Provider (SSP) and is integrated into the Windows operating system. It is commonly used in conjunction with Remote Desktop Protocol (RDP) to enable features like RemoteFX and to allow applications running on the remote desktop session to access network resources as if they were running locally. However, due to the nature of credential delegation, CredSSP has potential security implications if not configured and managed properly. It is important to ensure that both the client and server are running up-to-date versions of Windows and that appropriate security policies are in place to mitigate risks.