[PATCH] agent and scd: Don't prepend message digest

Werner Koch wk at gnupg.org
Wed Mar 13 16:17:24 CET 2013

On Wed, 13 Mar 2013 02:05, gniibe at fsij.org said:

> I assume that the only client of SCDaemon is GPG-Agent of the same
> version (or a bit old versions, but not all of past versions).  I

I might have agreed to it in the past, but we gpg 1.4 which needs to use
gpg-agent/scdaemon for smartcard access because scdameon has exclusive
access to the smartcard.  Thus gpg 1.4 uses "SCD foo" commands to
communicate with scdameon.  Also for signing and decryption.

Scute and Poldi also use SCD commands.  A quick check however shows that
they don't use "SCD" command for signing.  Thus this should not be a

> change will cause an error.  I think that there will be no problem,
> however, because there is always the prefix for RSA (for recent
> GPG-Agent).

Except for gpg 1.4.  We may eventually drop smartcard support from 1.4
but I would hesitate to do this right now.  Thus we need to keep the
prefixing for use by gpg 1.4 - we might be able to detect a usage
pattern if gpg 1.4 is in use and then enbale the prefixing.



Die Gedanken sind frei.  Ausnahmen regelt ein Bundesgesetz.

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