INFO: Using multiple Rebex libraries in a single project

When using multiple Rebex libraries in a single project (such as Rebex SFTP with Rebex Secure Mail, but any combination is possible), make sure all the libraries belong to the same release (such as 2019 R4).

Referencing different versions of Rebex libraries from a single assembly is not supported. This means - for example - that it's not possible to use Rebex SFTP 2020 R5 alongside Rebex Secure Mail 2019 R4 within a single project.

Background

All Rebex libraries reference Rebex.Common.dll and some reference Rebex.Networking.dll as well. When referencing multiple versions of different Rebex libraries, this creates a conflict. To solve this, make sure that only assemblies from the same release (such as 2020 R5) are used alongside each other - these are guaranteed to be compatible.

Example - different version of SFTP and Secure Mail

Let's consider following example. User has a license for following libraries:

  • Rebex Mail version 2019 R4 (old version)
  • Rebex SFTP version 2020 R5 (recent version)

What are your options?

Option 1: Upgrade both libraries to the current version

Pros
  • Both libraries are the same version and can be used in the same application.
  • Support for up-to-date security standards in both libraries.
  • Recent versions of both libraries are supported by Rebex.
Cons
  • Having to renew the old license.
  • The need to renew support for both library in future to keep both versions in sync.

Option 2: Upgrade to Rebex Total Pack

Upgrade to Total Pack and get access to the current version of all Rebex libraries.

Pros
  • Both libraries are the same version and can be used in the same application.
  • Support for up-to-date security standards in both libraries.
  • Recent versions of both libraries are supported by Rebex.
  • Get all Rebex libraries in one package. No problems with different versions in the future.
Cons
  • The need to upgrade to Rebex Total Pack, which might be more expensive than option 1. However, when consolidating more than two libraries, this is often the cheaper option. Contact sales@rebex.net for assistance.

Option 3: Downgrade both libraries to an old version

Use the same old version of both libraries. For example Rebex SFTP 2019 R4 and Rebex Secure Mail 2019 R4. This is discouraged.

Pros
  • No additional costs if you don't need any support. You already have access to old binaries for both libraries.
Cons
  • No recent bugfixes and enhancements.
  • Oudated security. Old versions may not support latest encryption ciphers and they might enable weak or vulnerable algorithms by default. You might already be unable to connect to servers that require up-to-date encryption.
  • When you need support later, or when your server drops support for old encryption algorithms, you may have to renew the support contract for both libraries anyway.
  • Limited support from Rebex. If you renew your support contract, we will do our best to support you. However, with the old version, our options might be limited. We don't backport bugfixes and enhancements unless a special agreement has been negotiated.