gpg: Change default and max AEAD chunk size to 4 MiB

--

This is per OpenPGP WG design team decision from 2021-08-13
(raising a new wall after exactly 60 years ;-)

Signed-off-by: Werner Koch <wk@gnupg.org>

2 files changed, 4 insertions, 4 deletions

diff --git a/doc/gpg.texi b/doc/gpg.texi
index 81dab5952..5919366d8 100644
--- a/doc/gpg.texi
+++ b/doc/gpg.texi
@@ -2391,7 +2391,7 @@ receiving side can check for transmission errors or tampering at the
 end of each chunk and does not need to delay this until all data has
 been received.  The used chunk size is 2^@var{n} byte.  The lowest
 allowed value for @var{n} is 6 (64 byte) and the largest is the
-default of 27 which creates chunks not larger than 128 MiB.
+default of 22 which creates chunks not larger than 4 MiB.
 
 @item --input-size-hint @var{n}
 @opindex input-size-hint
diff --git a/g10/gpg.c b/g10/gpg.c
index 54f7eb542..f3d645d4a 100644
--- a/g10/gpg.c
+++ b/g10/gpg.c
@@ -3974,15 +3974,15 @@ main (int argc, char **argv)
     /* Check chunk size.  Please fix also the man page if you change
      * the default.  The limits are given by the specs.  */
     if (!opt.chunk_size)
-      opt.chunk_size = 27; /* Default to the suggested max of 128 MiB.  */
+      opt.chunk_size = 22; /* Default to the suggested max of 4 MiB.  */
     else if (opt.chunk_size < 6)
       {
         opt.chunk_size = 6;
         log_info (_("chunk size invalid - using %d\n"), opt.chunk_size);
       }
-    else if (opt.chunk_size > (allow_large_chunks? 62 : 27))
+    else if (opt.chunk_size > (allow_large_chunks? 62 : 22))
       {
-        opt.chunk_size = (allow_large_chunks? 62 : 27);
+        opt.chunk_size = (allow_large_chunks? 62 : 22);
         log_info (_("chunk size invalid - using %d\n"), opt.chunk_size);
       }