GnuPG 2.4.4 still using legacy packets?

[Andrew Gallagher]

Hi, Peter.

On 13/11/2025 09:23, Peter Pentchev wrote:
> - so, IF NO `--rfc...` OPTION IS SPECIFIED, GnuPG HAS TO default to
>    the least common denominator

This is not how GnuPG's compliance options currently work though; 
non-default compliance options cause GnuPG to comply with *earlier* 
specs, to improve backwards compatibility at the expense of 
cryptographic strength.

It would be reasonable, and still solidly defensive, for GnuPG to emit 
the old packet framing iff a compliance option such as --rfc2440 was 
supplied, or if the key being encrypted to advertised old defaults, or 
if the key material uses an algorithm or packet version that pre-dates 
rfc4880. But it serves no purpose to continue to use the old format with 
modern cryptography that legacy code can't understand anyway.

A