When adding a new DUNDi peer in Asterisk, after updating dundi.conf and using astgenkey to create the RSA public/private key pair, Asterisk will emit the following error:

pbx_dundi.c:1331 update_key: No such key 'foo' for creating RSA encrypted shared key for '00:01:02:03:04:05'!

This is because the RSA keys are managed by res_crypto, not pbx_dundi. The solution is to reload res_crypto so that it re-scans /var/lib/asterisk/keys for the newly generated keys.

CLI> module reload res_crypto.so
-- Reloading module 'res_crypto.so' (Cryptographic Digital Signatures)
-- Loaded PUBLIC key 'foo'