A problem with exporting a key

[Tommi Höynälänmaa]

I exported a OpenPGP key in Thunderbird and imported it to GPG. When I export the public key with command "gpg -a --export KEYID" I get a key that is different from the public key in Thunderbird (the key that is attached to signed emails). What is the reason for this?

[David W. Hodgins]

I exported my key from both tb and gpg, used gpg --list-packets on each and
compared them. Here's the results ...

$ diff -u fred1 fred2
--- fred1 2021-09-04 15:42:39.568089392 -0400
+++ fred2 2021-09-04 15:42:44.028124860 -0400
@@ -1,12 +1,12 @@
-# off=0 ctb=99 tag=6 hlen=3 plen=525
+# off=0 ctb=c6 tag=6 hlen=3 plen=525 new-ctb
:public key packet:
version 4, algo 1, created 1601067532, expires 0
pkey[0]: [4096 bits]
pkey[1]: [17 bits]
keyid: 64FFE12354B3868B
-# off=528 ctb=b4 tag=13 hlen=2 plen=45
+# off=528 ctb=cd tag=13 hlen=2 plen=45 new-ctb
:user ID packet: "David W. Hodgins <davidw...@teksavvy.com>"
-# off=575 ctb=89 tag=2 hlen=3 plen=585
+# off=575 ctb=c2 tag=2 hlen=3 plen=585 new-ctb
:signature packet: algo 1, keyid 64FFE12354B3868B
version 4, created 1601067533, md5len 0, sigclass 0x13
digest algo 8, begin of digest 8e 3f
@@ -18,13 +18,13 @@
hashed subpkt 22 len 4 (pref-zip-algos: 2 3 1 0)
subpkt 16 len 8 (issuer key ID 64FFE12354B3868B)
data: [4095 bits]
-# off=1163 ctb=b9 tag=14 hlen=3 plen=525
+# off=1163 ctb=ce tag=14 hlen=3 plen=525 new-ctb
:public sub key packet:
version 4, algo 1, created 1601067534, expires 0
pkey[0]: [4096 bits]
pkey[1]: [17 bits]
keyid: 5ED32C9B723A3BA0
-# off=1691 ctb=89 tag=2 hlen=3 plen=566
+# off=1691 ctb=c2 tag=2 hlen=3 plen=566 new-ctb
:signature packet: algo 1, keyid 64FFE12354B3868B
version 4, created 1601067538, md5len 0, sigclass 0x18
digest algo 8, begin of digest 0f 2e

The difference is due to changes between pgp/gpg and opengpg. With opengpg, it
allows new certificates, though as far as I can see tb doesn't use them.
See https://www.openpgp.org/about/

Regards, Dave Hodgins

--
Change dwho...@nomail.afraid.org to davidw...@teksavvy.com for
email replies.