Stumbling myself a fair share on my local board with PGP (no need to see
PGP ¿Puedes enviar mensajes cifrados?), so exploring the PGP Newbie avenues myself.
Doing so, I’ve encountered the following issue:
- I’ve created a new PGP pair, and published my PGP public key (using Kleopatra).
- @FullNode published a message on a post, using my PGP public key to create his (not sure though which software he used).
- When I try to decrypt the message, I get:
El cifrado falló: sin protección de identidad (MDC) ..
Nombre de archivo incrustado: 'text.txt'
Pista:Si este archivo se cifró antes del año 2003 es muy posible que sea ilegítimo. Esto es debido a que la protección de integridad no se usaba ampliamente.
Si usted confía en que el archivo no se manipuló, debería volver a cifrarlo antes de forzar el descifrado.
Destinatario: ddmrddmr (E68F 78F5 AE23 5184)
Pressing "diagnostics" shows:
gpg: NOTA: el cifrado CAST5 no aparece en las preferencias del receptor
gpg: cifrado con clave de 3072 bits RSA, ID E68F78F5AE235184, creada el 2020-11-19
"ddmrddmr"
gpg: ATENCIÓN: la intgridad del mensaje no está protegida
gpg: Hint: If this message was created before the year 2003 it is
likely that this message is legitimate. This is because back
then integrity protection was not widely used.
gpg: Use the option '--ignore-mdc-error' to decrypt anyway.
gpg: decryption forced to fail!
The "force cypher" button on Kleopatra does nothing.
The quote’s above are in Spanglish, but the basic issue that does not allow for the message to be decrypted, seems to be that my cypher default algorithm on Kleopatra is "AES", while @ FullNode encrypted the message using "CAST5".
I would have expected the PGP tools to be able to figure it out on their own, but it seems not, which is also something to ponder (that or my Newbie PGP status). I tries changing from AES to CAST5 on Kleopatra’s configuration, but still got nowhere (when I closed/reopened Kleopatra, it went back to AES anyway).
Anyone know how frequent these cypher algorithm clashes occur, and whether it is tool dependent and/or resoluble using Kleopatra on the message decoding side ?
