From 464e7437f46e7c4199fa98dcc52b4d46e8d8a48e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ludovic=20Court=C3=A8s?= <ludo@gnu.org>
Date: Sun, 8 Nov 2020 23:35:45 +0100
Subject: [PATCH] publish: Create files in the cache as #o644.

Reported by Ricardo Wurmus <rekado@elephly.net>.

* guix/scripts/publish.scm (compress-nar): Add 'chmod' call to ensure
PORT is #o644, in the uncompressed case.
(bake-narinfo+nar): Likewise for the narinfo file.
* tests/publish.scm ("with cache"): Check permissions on CACHED and NAR.
---
 guix/scripts/publish.scm | 12 ++++++++++--
 tests/publish.scm        |  5 +++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/guix/scripts/publish.scm b/guix/scripts/publish.scm
index e8faf379e2..e3c8711f5b 100644
--- a/guix/scripts/publish.scm
+++ b/guix/scripts/publish.scm
@@ -583,7 +583,10 @@ (define nar
      ;; guarantee the TTL (see <https://bugs.gnu.org/28664>.)
      (with-atomic-file-output nar
        (lambda (port)
-         (write-file item port))))))
+         (write-file item port)
+         ;; Make the file world-readable, contrary to what
+         ;; 'with-atomic-file-output' does.
+         (chmod port (logand #o644 (lognot (umask)))))))))
 
 (define* (bake-narinfo+nar cache item
                            #:key ttl (compressions (list %no-compression))
@@ -615,7 +618,12 @@ (define (compressed-nar-size compression)
                                           #:nar-path nar-path
                                           #:compressions compressions
                                           #:file-sizes sizes)
-                          port)))))
+                          port)))
+
+             ;; Make the cached narinfo world-readable, contrary to what
+             ;; 'with-atomic-file-output' does, so that other users can rsync
+             ;; the whole cache.
+             (chmod port (logand #o644 (lognot (umask))))))
 
          ;; Make narinfo files for OTHERS hard links to NARINFO such that the
          ;; atime-based cache eviction considers either all the nars or none
diff --git a/tests/publish.scm b/tests/publish.scm
index e46e6256b7..cafd0f13a2 100644
--- a/tests/publish.scm
+++ b/tests/publish.scm
@@ -434,6 +434,11 @@ (define %gzip-magic-bytes
                  (< ttl 3600)))
 
               (wait-for-file cached)
+
+              ;; Both the narinfo and nar should be world-readable.
+              (= #o644 (stat:perms (lstat cached)))
+              (= #o644 (stat:perms (lstat nar)))
+
               (let* ((body         (http-get-port url))
                      (compressed   (http-get nar-url))
                      (uncompressed (http-get (string-append base "nar/"