[PATCH 2/3] Add ability to authorize viewing a repository

[Valentin Haenel]

This provides a mechanism for cgit to query an external program for repository
authorisation, e.g. gitolite. An additional config variable 'authorization'
contains the path and name of the executable to use.

Signed-off-by: Valentin Haenel <valentin.haenel at gmx.de>
---
 cgit.c       |   24 ++++++++++++++++++++++++
 cgit.h       |    1 +
 cgitrc.5.txt |    6 ++++++
 3 files changed, 31 insertions(+)

diff --git a/cgit.c b/cgit.c
index 101954e12a..f06528215d 100644
--- a/cgit.c
+++ b/cgit.c
@@ -123,6 +123,8 @@ void config_cb(const char *name, const char *value)
 		ctx.cfg.readme = xstrdup(value);
 	else if (!strcmp(name, "user-envvar"))
 		ctx.cfg.user_envvar = xstrdup(value);
+	else if (!strcmp(name, "authorization"))
+		ctx.cfg.authorization = xstrdup(value);
 	else if (!strcmp(name, "root-title"))
 		ctx.cfg.root_title = xstrdup(value);
 	else if (!strcmp(name, "root-desc"))
@@ -372,6 +374,7 @@ static void prepare_context(struct cgit_context *ctx)
 	ctx->cfg.summary_tags = 10;
 	ctx->cfg.max_atom_items = 10;
 	ctx->cfg.ssdiff = 0;
+	ctx->cfg.authorization = "/bin/true";
 	ctx->cfg.user_envvar = "REMOTE_USER";
 	ctx->env.cgit_config = xstrdupn(getenv("CGIT_CONFIG"));
 	ctx->env.http_host = xstrdupn(getenv("HTTP_HOST"));
@@ -545,6 +548,27 @@ static void process_request(void *cbdata)
 		return;
 	}
 
+	/* Here we do the authorization check.
+	 *
+	 * TODO
+	 * ----
+	 *  * figure out if this is the correct place to do the check
+	 *  * check that the authorization script exists and is executable
+	 *
+	 */
+	if (ctx->repo && system(fmt("%s %s %s",
+					ctx->cfg.authorization,
+					ctx->repo->name,
+					ctx->env.remote_user)) != 0) {
+		cgit_print_http_headers(ctx);
+		cgit_print_docstart(ctx);
+		cgit_print_pageheader(ctx);
+		cgit_print_error(fmt("Authorization failed for repo: '%s' and user: '%s'",
+					ctx->repo->name, ctx->env.remote_user));
+		cgit_print_docend();
+		exit(1);
+	}
+
 	if (ctx->repo && prepare_repo_cmd(ctx))
 		return;
 
diff --git a/cgit.h b/cgit.h
index 369dd8af8b..43f4f562f3 100644
--- a/cgit.h
+++ b/cgit.h
@@ -166,6 +166,7 @@ struct cgit_query {
 struct cgit_config {
 	char *agefile;
 	char *user_envvar;
+	char *authorization;
 	char *cache_root;
 	char *clone_prefix;
 	char *clone_url;
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index cd7327a4b3..d864289502 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -40,6 +40,12 @@ agefile::
 	function in libgit. Recommended timestamp-format is "yyyy-mm-dd
 	hh:mm:ss". Default value: "info/web/last-modified".
 
+authorization::
+	Specifies a path to authorization executable. The executable must take two
+	arguments: "<repository> <user> [<permissions>]". The permission is the
+	type of permission we wish to check for, e.g. "R" or "RW" or "RW+". A
+	common use case is to call gitolite through this machinery.
+
 cache-root::
 	Path used to store the cgit cache entries. Default value:
 	"/var/cache/cgit". See also: "MACRO EXPANSION".
-- 
1.7.9.5