[Mono-dev] ECDSA support

[Edward Ned Harvey (mono)]

> From: mono-devel-list-bounces at lists.ximian.com [mailto:mono-devel-list-
> bounces at lists.ximian.com] On Behalf Of techi eth
> 
> Is mono support ciphers ECDSA ?
> Mono 4.0.0 release show some handling of same under mono-
> 4.0.0/external/referencesource/System.Core/System/Security/Cryptograph
> y.
> Please let me know how to use the same in build.

Just in case you want, there's an example of bouncycastle ECDH usage here:
https://github.com/rahvee/CBcrypt/blob/master/CBcrypt/CBcrypt/CBcrypt.cs#L129

Depending on what you want to do, you might even use CBCryptKey from the above project (also available in NuGet). I found bouncycastle's API quite lacking in documentation, and kind of difficult to use, so the most useful stuff was abstracted to
https://github.com/rahvee/CBcrypt/blob/master/CBcrypt/CBcrypt/CBCryptKey.cs 

The ECDH and ECDSA keys are exactly the same - but it's recommended you be explicit (don't just use EC), and only use a key for its intended purpose. As far as I know it's not well studied if there might be some bad interaction between the ECDH algorithms and ECDSA algorithms. In other words, don't use a single key for both ECDH and ECDSA. Generate separate keys if you need both.