eThinking about this further, is there any to use the details from "--list-packets" in order to extract the signature.
For example, the output from the signing below produces:- >C:\>gpg --list-packets R:\Temp\signedfile.asc ># off=0 ctb=a3 tag=8 hlen=1 plen=0 indeterminate >:compressed packet: algo=1 ># off=2 ctb=90 tag=4 hlen=2 plen=13 >:onepass_sig packet: keyid DC00AF5F572550CB > version 3, sigclass 0x00, digest 8, pubkey 22, last=1 ># off=17 ctb=ac tag=11 hlen=2 plen=55 >:literal data packet: > mode b (62), created 1624466686, name="inputfile.txt", > raw data: 36 bytes ># off=74 ctb=88 tag=2 hlen=2 plen=117 >:signature packet: algo 22, keyid DC00AF5F572550CB > version 4, created 1624466686, md5len 0, sigclass 0x00 > digest algo 8, begin of digest dc 7e > hashed subpkt 33 len 21 (issuer fpr v4 > 1797615E1E1CA3357FD23365DC00AF5F572550CB) > hashed subpkt 2 len 4 (sig created 2021-06-23) > subpkt 16 len 8 (issuer key ID DC00AF5F572550CB) > data: [256 bits] > data: [256 bits] Would the:- ># off=74 ctb=88 tag=2 hlen=2 plen=117 provide enough inforation to extract the signature? Does it vary depending upon whether the signature is ASCII armored? Or am I barking up the wrong tree??? Best wishes, Matthew ------ >From: Matthew Richardson via Gnupg-users <gnupg-users@gnupg.org> >To: gnupg-users@gnupg.org >Cc: >Date: Sun, 20 Jun 2021 17:52:53 +0100 >Subject: Detaching signature from signed object >Is there any way in GnuPG to detach (or extract) a signature from a signed >object? For example, a signed object is created with:- > >>gpg --armor --output signedfile.asc --sign inputfile.txt > >where what is wanted is a detached signature which would verify against >inputfile.txt. > >This feature is in PGP 2:- > >>pgp -sa inputfile.txt -o signedfile.asc >>pgp -b signedfile.asc -o verified.txt > >which also produces verified.pgp as the detached signature. The feature is >described (briefly) in the PGP 2 documentation thus:- > >>To detach a signature certificate from a signed message: >> pgp -b ciphertextfile > >The reason for asking is that I operate a service [1], which currently used >PGP 2, and which would benefit from more recent crypto, but which also uses >"pgp -b" extensively. > >Best wishes, >Matthew > >[1] http://www.itconsult.co.uk/stamper.htm _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users