updprefs command and changing key

[David Shaw]

On Mar 13, 2010, at 5:14 AM, MFPA wrote:

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> Hi
> 
> 
> On Saturday 13 March 2010 at 12:07:08 AM, in
> <mid:DE002B15-FA18-49A1-B7B0-5AFAAF829339 at jabberwocky.com>, David Shaw
> wrote:
> 
> 
>> On Mar 12, 2010, at 6:31 PM, Faramir wrote:
> 
>>> is there a way to disable the usage of 3DES in GnuPG, when
>>> encrypting?
> 
>> Patch the source :)
> 
>> There is no way other than that.
> 
> Wouldn't "--disable-cipher-algo 3DES" achieve this?

Try it - make a key that has only 3DES in its preferences, and then try encrypting to it with --disable-cipher-algo 3DES set.  You'll end up with 3DES anyway.  The way the code is structured, if the cipher selection algorithm fails (and it will in this case - the key requires 3DES, but you've disabled 3DES) so GPG has to resolve the crisis somehow - and it resolves it by using 3DES as it "knows" that OpenPGP requires it to be present.

David