support/download: add explicit no-hash support

Add support to explicitly state that an archive has no hash.

This can be used for archives downloaded from a repository, like a
git-clone or a subversion checkout, or using the github helper.

This will come in handy when we'll eventually make hashes mandatory as
soon as a .hash file exists: for some packages, like gcc, some versions
are downloaded as archives from upstream, while other versions may come
from a GitHub repository (via the github herlper).

In this case, a .hash file would exist, that contains hashes for the
downloaded tarballs, but archives downloaded from the repository would
not have a hash (since it is currently not possible to have reproducible
such archives). So, we'd need a way to explicitly state there is no
hash, on purpose, for those archives.

So, add 'none' as a new type of hash.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Reviewed-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/support/download/check-hash b/support/download/check-hash
index cee64ef31..7a30d5b31 100755
--- a/support/download/check-hash
+++ b/support/download/check-hash
@@ -38,7 +38,11 @@ check_one_hash() {
     # Note: md5 is supported, but undocumented on purpose.
     # Note: sha3 is not supported, since there is currently no implementation
     #       (the NIST has yet to publish the parameters).
+    # Note: 'none' means there is explicitly no hash for that file.
     case "${_h}" in
+        none)
+            return 0
+            ;;
         md5|sha1)                       ;;
         sha224|sha256|sha384|sha512)    ;;
         *) # Unknown hash, exit with error