Digitally Signing LAN Zoo Plugins

by Dale Fugier (Last modified: 25 Jun 2021)

This guide discusses how to digitally sign LAN Zoo and Rhino plugins.

Overview

To add plugins to the LAN Zoo, and to call the license functions from within your Rhino plugin, you must digitally sign your plugins using a certificate signed by the Robert McNeel & Associates Code Signing Authority.

Generate Private Key & Certificate Signing Request

Follow these steps to generate the necessary info to forward to Robert McNeel & Associates Code Signing Authority…

Download and install the latest OpenSSL. Note, downloading and installing the “light” version (smaller download) is sufficient.
After installation, use Windows Explorer to navigate to the OpenSSL installation folder and double-click on start.bat found in the Bin folder.
From the Windows command prompt that opens, navigate to your plug-in’s project folder.
Save the contents of mcneelcodesigning.zip to your plug-in’s project folder.
From the command prompt, run CreateRequest.bat <filename>, where filename is the name (without an extension) that will be used to save your private key (.key), certificate signing request (.csr), and final signed digital certificate (.crt).
You will be prompted to answer some questions. Be sure to answer them correctly…

C:\Dev\Zoo> CreateRequest.bat TestZooPluginKey
Loading 'screen' into random state - done
Generating RSA private key, 4096 bit long modulus
................................................................................
e is 65537 (0x10001)
Loading 'screen' into random state - done
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) []: <COUNTRY NAME>
State or Province Name (full name) []: <STATE OR PROVINCE>
Locality Name (eg, city) []: <CITY>
Organization Name (eg, company) []: <ORGANIZATON>
Organizational Unit Name (eg, section) []: <ORGANIZATIONAL UNIT>
Common Name (eg, your websites domain name) []: <DOMAIN NAME>

Please enter the following 'extra' attributes
to be sent with your certificate request
A challenge password []: <PASSWORD>

Saved private key: 'TestZooPluginKey.key'
Saved CSR: 'TestZooPluginKey.csr'

Requesting a Signed Digital Certificate

Email the certificate signing request (.csr) created above to Brian Gillespie along with a certificate request.
We will process your request and, if it is approved, will send you a signed digital certificate (.crt).

Creating a Personal Information Exchange

To digitally sign your LAN Zoo or Rhino plugin, convert the signed digital certificate (.crt), emailed to you upon approval, into a personal information exchange (.pfx) file…

Copy the signed digital certificate (.crt) you receive into the same folder as your private key (.key) and certificate signing request (.csr).
Use Windows Explorer to navigate to the OpenSSL installation folder and double-click on start.bat found in the Bin folder.
From the Windows command prompt that opens, navigate to the above folder.
From the command prompt, run MakePfxFile.bat <filename>, where filename is the name (without an extension)…

C:\Dev\Zoo\TestZooPlugin>MakePfxFile.bat TestZooPluginKey
Loading 'screen' into random state - done
Enter Export Password: <PRESS ENTER>
Verifying - Enter Export Password: <PRESS ENTER>
Created 'TestZooPluginKey.pfx'. Use this to sign your executable code.

Sign Your Plugins

Now that you have a personal information exchange (.pfx), you can use it to sign LAN Zoo and Rhino plugins.

Open a Visual Studio Command Prompt.
Use Signtool.exe, with the following syntax, to digitally sign your plugins…

signtool.exe sign /f <filename>.pfx /t http://timestamp.verisign.com/scripts/timstamp.dll /v <plugin>

For example:

C:\Dev\Zoo\TestZooPlugin> signtool sign /f TestZooPluginKey.pfx /t http://timestamp.verisign.com/scripts/timstamp.dll /v TestZooPlugin.dll
The following certificate was selected:
    Issued to: MCNEEL.COM
    Issued by: McNeel Software Development
    Expires:   <DATE>
    SHA1 hash: <HASH>

Done Adding Additional Store
Successfully signed and timestamped: TestZooPlugin.dll

Number of files successfully Signed: 1
Number of warnings: 0
Number of errors: 0