RSA Decryption with public key?

We have an .NET 2.0 application that requires verifying that an external
application knows the private key in a public key, private key pair.

The verification protocol developed by manufacturer of the external
application involves sending the external application known data, allowing
the external application to encrypt the data using the private key, and then
verifying that the returned cipher text matches the original data once
decrypted by our application with the public key.

Note: The returned data is encrypted by the private key -not signed!

From our research, the RSACryptoServiceProvider in the Framework does not
directly support this type of protocol. For reference:

http://social.msdn.microsoft.com/Forums/en-US/netfxbcl/thread/7fd9ab50-40c7-47c2-ae80-04e5ccad839d/

http://www.eggheadcafe.com/software/aspnet/31582085/no-way-to-encrypt-with-pr.aspx

Has anyone found a suitable workaround for this? We have had some success
with Bouncy Castle. (http://www.bouncycastle.org/) However, we would prefer
not to include additional third party libraries due to legal concerns and
additional product requirements.

Thanks in advance!


.

Relevant Pages

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  • CryptImportKey NTE_BAD_KEY error.
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  • CryptImportKey NTE_BAD_KEY error.
    ... of the private key is just fine but when I try to import the public key I ... // This Asymetric key set will be used to create the Autherization Code. ... delete psBuffer; ...
    (microsoft.public.security)