Feature #806
closedimplementation of digest auth MD5-sess does not conform to rfc2617
Description
The digest auth implementation using algo=MD5-sess is broken.
It seems that someone just integrated the "sample implementation" that can
be found in rfc 2617 without having read section 3.2.2.2:
Updated by gstrauss almost 8 years ago
- Description updated (diff)
- Category changed from core to mod_auth
- Assignee deleted (
jan)
Updated by gstrauss almost 8 years ago
- Related to Bug #1844: Serious security problem in Digest Authentication added
Updated by gstrauss almost 8 years ago
- Tracker changed from Bug to Feature
- Status changed from New to Wontfix
- Priority changed from Normal to Low
- Target version deleted (
1.4.41)
Related issue #1844 will be fixed in lighttpd 1.4.41
Digest algorithm="md5" is the default and will be implemented in lighttpd 1.4.41 mod_auth (not yet released)
Digest algorithm="md5-sess" is not correctly implemented in lighttpd, and so its use is not recommend.
https://redmine.lighttpd.net/projects/lighttpd/wiki/Docs_ModAuth will be updated to state this explicitly.
Please note that as this is being written, Apache mod_auth_digest does not implement algorithm="md5-sess" either.
https://httpd.apache.org/docs/trunk/mod/mod_auth_digest.html
MD5-sess is not correctly implemented yet.
RFC7616 changes the required Digest algorithm to SHA2-256 but allows MD5 algorithm for backwards compatibility. Therefore, there are no plans to implement Digest algorithm="md5-sess". (In the future, SHA2-256 may be implemented in mod_auth.)
Please note that Digest auth is not cryptographically secure. It exists merely to be a better choice than Basic auth, addressing the security design flaw of passing clear-text username and password in Basic auth. There are more secure protocol transports and methods, such as TLS and public key auth using SSL client certs. This or other options (e.g. OAuth) should be preferred over Basic or Digest auth.
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