Re: [PATCH] http.c: shell command evaluation for extraheader
Johannes,
On March 5, 2018 1:47 PM, Johannes Schindelin <Johannes.Schindelin@gmx.de> wrote:
> As the credential-helper is already intended for sensitive data, and as it
> already allows to interact with a helper, I would strongly assume that it
> would make more sense to try to extend that feature (instead of the simple
> extraHeader one).
To confirm you are suggesting that the credential struct, defined in credential.h, be extended to include a headers array, like so:
--- a/credential.h
+++ b/credential.h
@@ -15,6 +15,7 @@ struct credential {
char *protocol;
char *host;
char *path;
+ char **headers
};
#define CREDENTIAL_INIT { STRING_LIST_INIT_DUP }
> This would also help alleviate all the quoting/dequoting issues involved
> with shell scripting.
>
> Besides, the http.extraHeader feature was designed to accommodate all
> kinds of extra headers, not only authentication ones (and indeed, the
> authentication was only intended for use in build agents, where both
> environment and logging can be controlled rather tightly).
I realise that my examples are scoped for auth, but I can conceive of other mutating headers that are not explicitly authentication related, and could benefit from shell execution before fetch, pull, push actions.
> I also see that in your implementation, only the extraHeader value is
> evaluated, without any access to the rest of the metadata (such as URL,
> and optionally specified user).
>
> It would probably get a little more complicated than a shell script to
> write a credential-helper that will always be asked to generate an
> authentication, but I think even a moderate-level Perl script could be
> used for that, and it would know the URL and user for which the
> credentials are intended...
You are correct; the scope provided by http.<url>.* is enough to meet my use cases, however I agree the lack of access to metadata limits what can be done within in the context of the shell, and makes the case for a credential-helper implementation stronger. I think there is something to be said about the simplicity and user-friendliness of allowing shell scripts for semi-complex config options, but authentication is a task that should be handled well and centrally, thus extending the credential-api makes sense.
Without Wax,
Colin Arnott