Index of /dist/META
Name Last modified Size Description
Parent Directory -
etc/ 2018-05-04 21:07 -
ROOT 2019-05-22 19:03 13K
mk-root 2018-11-10 10:21 9.5K
ASF-key.txt 2018-03-25 10:12 3.2K
ASF.asc 2018-03-24 06:06 819
Makefile 2018-10-18 08:27 817
config 2018-08-16 13:23 602
ASF 2018-03-24 06:06 312
ROOT.asc 2019-05-22 19:03 181
/dist/META/ -- introduction
End-users download ASF artifacts. An end-user wants to be
certain that the artifact is endorsed by the ASF.
We assume that the end-user is prepared to trust :
-- a ASF company PGP key,
-- anything signed by the ASF key,
-- and (a priori) nothing else.
Each ASF artifact is signed by some release manager [RM].
artifact : /dist/PROJ/foo.tar.gz
signature : /dist/PROJ/foo.tar.gz.asc
signed by : key deadbeefdeadbeef -- email@example.com
Why should an end-user believe that /dist/PROJ/foo.tar.gz
is endorsed by the ASF ?
For an end-user it is easy to check the signature, and establish
that it was created by key deadbeefdeadbeef <firstname.lastname@example.org>.
For an end-user is almost impossible to establish that (RM)
email@example.com is authorised to release and sign artifact
Actually, the end-user doesn't care which RM signed the artifact.
The end-user just wants be certain that the artifact is endorsed
by the ASF.
How do we bridge the gap between "signed by key deadbeefdeadbeef
(firstname.lastname@example.org)" and "endorsed by the ASF" ?
We present the end-user with a hierachical model of the ASF :
-- the ASF authorises PMC's to release artifacts
-- a PMC authorises certain RM's to release certain artifacts
The "endorsements" are stored in META files :
-- a META file has lines like "key KEY1 signs PATH" ;
-- a META file is signed by, say, "KEY2 -- META-SIGNER".
-- meaning : META-SIGNER authorises (the owner of) KEY1
to sign artifact PATH,
-- as endorsement : META-SIGNER endorses artifact PATH,
if signed by KEY1.
-- the "endorsements" in a META file are useless, unless
the META file is endorsed elsewhere (higher in the tree).
Directory /dist/META/ contains the ASF's root-of-authority files.
These files authorise /dist/$pmc/META files, which in turn
authorise artifacts in /dist/$pmc/ etc.
In short, this is how it works :
-- /dist/META/ASF is endorsed (signed) by the ASF-key
-- /dist/META/ASF endorses /dist/META/ROOT
-- /dist/META/ROOT endorses /dist/$pmc/META
-- /dist/$pmc/META endorses /dist/$pmc/artifacts
-- /dist/$pmc/META endorses /dist/$pmc/sub/META
-- /dist/$pmc/sub/META endorses /dist/$pmc/sub/artifacts
-- Actually, when a META file contains a line like :
key KEY signs PATH
the PATH is interpreted as a prefix.
The line authorises KEY to sign files PATH*.
This makes the META files denser, and more resilient
to change (the addition/removal of releases).
-- The prefix is interpreted relative to the META file, so file
authorises KEY to sign files
More info : https://checker.apache.org/doc/README.html#ch-meta
/dist/META/ -- Files
-- ASF-key.txt : public ASF company key 36625D435EF870E1
-- ASF : specifies which keys may sign file ROOT
-- ASF.asc : must be created with ASF-key 36625D435EF870E1
-- ROOT : specifies which keys may sign /dist/$pmc/META
-- ROOT.asc : must be signed by a key listed in file ASF
It would be more logical to have file /dist/META, /dist/META.asc
-- META signed by the company key
-- authorising /dist/$pmc/META files
The problem with such a setup is that it requires using
the company key each time /dist/META changes.
To avoid that we could introduce /dist/ROOT, /dist/ROOT.asc,
as above, resulting in 4 extra (meta) files in /dist/.
To avoid clutter in /dist/, these 4 files are placed in dist/META/,
and prefixes in META/ASF, META/ROOT are relative /dist/.