Mstsc rdp fix

[aschumann-virtualcable]

This pull request introduces support for cryptographically signing RDP files on the server side, ensuring enhanced security and authenticity for RDP connections. The main changes add the ability to generate and append signatures to RDP files, expose a REST API endpoint for signing RDP content, and update the RDP transport scripts to utilize this new functionality. Additionally, the cryptographic code has been refactored for better organization.

RDP File Signing Functionality:

• Added a new module, rdp.py, under server/src/uds/core/managers/crypto/ that implements RDP file signing using PKCS7 signatures, loading certificates and keys from configurable paths. The signing process appends signature and signscope lines to RDP files.
• Refactored the crypto manager: moved RDP-related signing logic from crypto.py into the new crypto/rdp.py module, and exposed a sign_rdp method on the CryptoManager for signing RDP data. [1] [2]

REST API and Backend Integration:

• Added a new REST API command rdp_signature to the client endpoint, which signs provided RDP content using the server's certificate and returns the signed result. [1] [2] [3]

RDP Transport and Ticketing:

• Updated RDP transport modules (rdp.py, rdptunnel.py) to generate a short-lived ticket for each RDP signing operation, passing this ticket to the signing process for validation and traceability. [1] [2] [3]

Windows RDP Script Updates:

• Modified Windows RDP connection scripts to invoke the new signing functionality before saving the RDP file, ensuring all generated RDP files are cryptographically signed. [1] [2]
• Updated signature files for Windows scripts to match the new signing output. [1] [2]

Submodule Update:

• Updated the client submodule to a new commit, likely to support or consume the new RDP signing features.