This module is an alpha version of an Apache2 httpd module that implements a data integrity check in accordance with RFC 3230 (https://tools.ietf.org/html/rfc3230). It has been tested with various HTTP header combinations and returns the correct digests according to specifications in RFC 3230. Currently, ADLER32, MD5 and SHA-1 checksums are supported.
Nota bene:
The module does not calculate or cache digests for files that are copied directly into the directory configured to be served via webDAV. There is, however, the option to use a combination of inotifywait and a fitting script on system level to achieve that. If you are interested in such an implementation, please let us know.
Version 0.1 was shipped without digest caching and can be found under the tag v0.1. As the main branch is subject to change, please download and use the newest release for a stable version.
Dependencies: zlib >= v1.2.9 (adler32_z was declared as uLong before v1.2.9, now is size_t)
Installation: The module is compiled, installed and activated (-cia) via
sudo apxs -cia mod_want_digest.c
on the target machine.
Currently, there is one config option for the module that sets the digest caching location on a per-directory basis (the directive to use in a -directive is DigestRootDir). The digests will be cached in the DigestRootDir from the directory in which the directive is placed.
Example configuration:
<Directory "/mnt/data">
# other configuration options
DigestRootDir /var/run/apache2/digests
# other configuration options
</Directory>
Usage: Example HTTP request via cURL:
curl --head https://foo.bar.com/foobar.txt -H "Want-Digest: MD5"
HTTP/1.1 200 OK
Date: Mon, 12 Oct 2020 12:49:41 GMT
Server: Apache/2.4.41 (Ubuntu)
Digest: MD5=TZYmtg997D5xY2K5m/CKXg==
Last-Modified: Thu, 08 Oct 2020 11:59:29 GMT
Accept-Ranges: bytes
Content-Length: 3000678009
Vary: Accept-Encoding
Content-Type: text/plain
The module has been developed by T. Wetzel and P. Millar at Deutsches Elektronen-Synchrotron DESY.
The project is licensed under the Apache 2.0 license.
mod_want_digest uses the linux kernel model where git is not only source repository, but also the way to track contributions and copyrights.
Each submitted patch must have a "Signed-off-by" line. Patches without this line will not be accepted.
The sign-off is a simple line at the end of the explanation for the patch, which certifies that you wrote it or otherwise have the right to pass it on as an open-source patch. The rules are pretty simple: if you can certify the below:
Developer's Certificate of Origin 1.1
By making a contribution to this project, I certify that:
(a) The contribution was created in whole or in part by me and I
have the right to submit it under the open source license
indicated in the file; or
(b) The contribution is based upon previous work that, to the best
of my knowledge, is covered under an appropriate open source
license and I have the right under that license to submit that
work with modifications, whether created in whole or in part
by me, under the same open source license (unless I am
permitted to submit under a different license), as indicated
in the file; or
(c) The contribution was provided directly to me by some other
person who certified (a), (b) or (c) and I have not modified
it.
(d) I understand and agree that this project and the contribution
are public and that a record of the contribution (including all
personal information I submit with it, including my sign-off) is
maintained indefinitely and may be redistributed consistent with
this project or the open source license(s) involved.
then you just add a line saying ( git commit -s )
Signed-off-by: Random J Developer <[email protected]>
using your real name (sorry, no pseudonyms or anonymous contributions.)