I ran into this problem when attempting to send an encrypted mail via
mutt.
Problem:
--------
I wanted to send a secret mail to my corespondant. We'll call her
Alice.
In mutt, Alice's key for encryption couldn't be found. Entering the key
ID (which _was_ in my local keyring) would flash text too fast to see.
A name/address search turned up no results.
Backing out to command line, I created a file and attempted to encrypt
it.
e.g.:
$ fortune -l > makesecret
$ gpg --armor -e --recipient <keyid> makesecret
Output was "unusable public key".
Hrm.
Solution:
---------
I was apparently missing a subkey from my copy of Alice's public key.
Re-import the key from a keyserver that didn't mangle the subkey. Why
my primary keyserver (pgp.mit.edu) wasn't doing this properly isn't
clear. More curiously, my corespondant claims to have earlier encrypted
mail from me.
If anyone has any additional information or background, I'd appreciate
it. Especially the bits about some keyservers mangling keys.
Several false positives:
------------------------
There were a number of hits for the error message, few of which actually
pointed at the solution (hence this post).
- Re-downloading the key from my regular keyserver didn't work.
- Alice's key wasn't trusted by me, and an untrusted key couldn't be
used. Not true. Edited the trust value, didn't work either.
- Alice's key wasn't self-signed. It was. Didn't work.
- I needed an RSA encyrption subkey. I added one. Didn't work.
Something of a curiosity.
Peace.
--
Karsten M. Self <kmself@ix.netcom.com> http://kmself.home.netcom.com/
What Part of "Gestalt" don't you understand?
I could give you my word as a Spaniard?
No good. I've known too many Spaniards.
- Princess Bride
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