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authorJason A. Donenfeld <Jason@zx2c4.com>2014-01-14 21:49:31 +0100
committerJason A. Donenfeld <Jason@zx2c4.com>2014-01-16 02:28:12 +0100
commitd6e9200cc35411f3f27426b608bcfdef9348e6d3 (patch)
tree9cdd921b03465458d10b99ff4357f79a810501c0 /cgit.c
parent3741254a6989b2837cd8d20480f152f0096bcb9a (diff)
auth: add basic authentication filter framework
This leverages the new lua support. See filters/simple-authentication.lua for explaination of how this works. There is also additional documentation in cgitrc.5.txt. Though this is a cookie-based approach, cgit's caching mechanism is preserved for authenticated pages. Very plugable and extendable depending on user needs. The sample script uses an HMAC-SHA1 based cookie to store the currently logged in user, with an expiration date. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Diffstat (limited to 'cgit.c')
-rw-r--r--cgit.c96
1 files changed, 94 insertions, 2 deletions
diff --git a/cgit.c b/cgit.c
index f3fe56b..c52ef33 100644
--- a/cgit.c
+++ b/cgit.c
@@ -192,6 +192,8 @@ static void config_cb(const char *name, const char *value)
ctx.cfg.commit_filter = cgit_new_filter(value, COMMIT);
else if (!strcmp(name, "email-filter"))
ctx.cfg.email_filter = cgit_new_filter(value, EMAIL);
+ else if (!strcmp(name, "auth-filter"))
+ ctx.cfg.auth_filter = cgit_new_filter(value, AUTH);
else if (!strcmp(name, "embedded"))
ctx.cfg.embedded = atoi(value);
else if (!strcmp(name, "max-atom-items"))
@@ -378,6 +380,10 @@ static void prepare_context(struct cgit_context *ctx)
ctx->env.script_name = getenv("SCRIPT_NAME");
ctx->env.server_name = getenv("SERVER_NAME");
ctx->env.server_port = getenv("SERVER_PORT");
+ ctx->env.http_cookie = getenv("HTTP_COOKIE");
+ ctx->env.http_referer = getenv("HTTP_REFERER");
+ ctx->env.content_length = getenv("CONTENT_LENGTH") ? strtoul(getenv("CONTENT_LENGTH"), NULL, 10) : 0;
+ ctx->env.authenticated = 0;
ctx->page.mimetype = "text/html";
ctx->page.charset = PAGE_ENCODING;
ctx->page.filename = NULL;
@@ -593,11 +599,92 @@ static int prepare_repo_cmd(struct cgit_context *ctx)
return 0;
}
+static inline void open_auth_filter(struct cgit_context *ctx, const char *function)
+{
+ cgit_open_filter(ctx->cfg.auth_filter, function,
+ ctx->env.http_cookie ? ctx->env.http_cookie : "",
+ ctx->env.request_method ? ctx->env.request_method : "",
+ ctx->env.query_string ? ctx->env.query_string : "",
+ ctx->env.http_referer ? ctx->env.http_referer : "",
+ ctx->env.path_info ? ctx->env.path_info : "",
+ ctx->env.http_host ? ctx->env.http_host : "",
+ ctx->env.https ? ctx->env.https : "",
+ ctx->qry.repo ? ctx->qry.repo : "",
+ ctx->qry.page ? ctx->qry.page : "",
+ ctx->qry.url ? ctx->qry.url : "");
+}
+
+#define MAX_AUTHENTICATION_POST_BYTES 4096
+static inline void authenticate_post(struct cgit_context *ctx)
+{
+ if (ctx->env.http_referer && strlen(ctx->env.http_referer) > 0) {
+ html("Status: 302 Redirect\n");
+ html("Cache-Control: no-cache, no-store\n");
+ htmlf("Location: %s\n", ctx->env.http_referer);
+ } else {
+ html("Status: 501 Missing Referer\n");
+ html("Cache-Control: no-cache, no-store\n\n");
+ exit(0);
+ }
+
+ open_auth_filter(ctx, "authenticate-post");
+ char buffer[MAX_AUTHENTICATION_POST_BYTES];
+ int len;
+ len = ctx->env.content_length;
+ if (len > MAX_AUTHENTICATION_POST_BYTES)
+ len = MAX_AUTHENTICATION_POST_BYTES;
+ if (read(STDIN_FILENO, buffer, len) < 0)
+ die_errno("Could not read POST from stdin");
+ if (write(STDOUT_FILENO, buffer, len) < 0)
+ die_errno("Could not write POST to stdout");
+ /* The filter may now spit out a Set-Cookie: ... */
+ cgit_close_filter(ctx->cfg.auth_filter);
+
+ html("\n");
+ exit(0);
+}
+
+static inline void authenticate_cookie(struct cgit_context *ctx)
+{
+ /* If we don't have an auth_filter, consider all cookies valid, and thus return early. */
+ if (!ctx->cfg.auth_filter) {
+ ctx->env.authenticated = 1;
+ return;
+ }
+
+ /* If we're having something POST'd to /login, we're authenticating POST,
+ * instead of the cookie, so call authenticate_post and bail out early.
+ * This pattern here should match /?p=login with POST. */
+ if (ctx->env.request_method && ctx->qry.page && !ctx->repo && \
+ !strcmp(ctx->env.request_method, "POST") && !strcmp(ctx->qry.page, "login")) {
+ authenticate_post(ctx);
+ return;
+ }
+
+ /* If we've made it this far, we're authenticating the cookie for real, so do that. */
+ open_auth_filter(ctx, "authenticate-cookie");
+ ctx->env.authenticated = cgit_close_filter(ctx->cfg.auth_filter);
+}
+
static void process_request(void *cbdata)
{
struct cgit_context *ctx = cbdata;
struct cgit_cmd *cmd;
+ /* If we're not yet authenticated, no matter what page we're on,
+ * display the authentication body from the auth_filter. This should
+ * never be cached. */
+ if (!ctx->env.authenticated) {
+ ctx->page.title = "Authentication Required";
+ cgit_print_http_headers(ctx);
+ cgit_print_docstart(ctx);
+ cgit_print_pageheader(ctx);
+ open_auth_filter(ctx, "body");
+ cgit_close_filter(ctx->cfg.auth_filter);
+ cgit_print_docend();
+ return;
+ }
+
cmd = cgit_get_cmd(ctx);
if (!cmd) {
ctx->page.title = "cgit error";
@@ -911,6 +998,7 @@ int main(int argc, const char **argv)
int err, ttl;
cgit_init_filters();
+ atexit(cgit_cleanup_filters);
prepare_context(&ctx);
cgit_repolist.length = 0;
@@ -948,18 +1036,22 @@ int main(int argc, const char **argv)
cgit_parse_url(ctx.qry.url);
}
+ /* Before we go any further, we set ctx.env.authenticated by checking to see
+ * if the supplied cookie is valid. All cookies are valid if there is no
+ * auth_filter. If there is an auth_filter, the filter decides. */
+ authenticate_cookie(&ctx);
+
ttl = calc_ttl();
if (ttl < 0)
ctx.page.expires += 10 * 365 * 24 * 60 * 60; /* 10 years */
else
ctx.page.expires += ttl * 60;
- if (ctx.env.request_method && !strcmp(ctx.env.request_method, "HEAD"))
+ if (!ctx.env.authenticated || (ctx.env.request_method && !strcmp(ctx.env.request_method, "HEAD")))
ctx.cfg.nocache = 1;
if (ctx.cfg.nocache)
ctx.cfg.cache_size = 0;
err = cache_process(ctx.cfg.cache_size, ctx.cfg.cache_root,
ctx.qry.raw, ttl, process_request, &ctx);
- cgit_cleanup_filters();
if (err)
cgit_print_error("Error processing page: %s (%d)",
strerror(err), err);