From bb2a811bf4c05013aa5b3dbe437d7caf1fea4974 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Mon, 30 May 2005 06:08:54 +0000
Subject: [PATCH] r7087: always run the /scripting/preauth.esp page before
 processing any request. If this page produces any output then that output is
 sent to the browser and the request is not processed

This allows us to ensure that all pages are authenticated
(This used to be commit 6a876d66119a79f7922f44d36c116eee72dd76f9)
---
 source4/web_server/http.c | 70 ++++++++++++++++++++++++++++++---------
 1 file changed, 55 insertions(+), 15 deletions(-)

diff --git a/source4/web_server/http.c b/source4/web_server/http.c
index e8dba5a754b..46b3106518e 100644
--- a/source4/web_server/http.c
+++ b/source4/web_server/http.c
@@ -32,6 +32,7 @@
 #include "dlinklist.h"
 
 #define SWAT_SESSION_KEY "_swat_session_"
+#define HTTP_PREAUTH_URI "/scripting/preauth.esp"
 
 /* state of the esp subsystem for a specific request */
 struct esp_state {
@@ -121,7 +122,7 @@ static const char *http_local_path(struct websrv_context *web, const char *url)
 	if (url[0] != '/') return NULL;
 
 	for (i=0;url[i];i++) {
-		if ((!isalnum(url[i]) && !strchr("./", url[i])) ||
+		if ((!isalnum(url[i]) && !strchr("./_", url[i])) ||
 		    (url[i] == '.' && strchr("/.", url[i+1]))) {
 			return NULL;
 		}
@@ -164,6 +165,7 @@ static int http_readFile(EspHandle handle, char **buf, int *len, const char *pat
 	return 0;
 
 failed:
+	DEBUG(0,("Failed to read file %s - %s\n", path, strerror(errno)));
 	if (fd != -1) close(fd);
 	talloc_free(*buf);
 	*buf = NULL;
@@ -385,6 +387,7 @@ static void http_simple_request(struct websrv_context *web)
 	/* looks ok */
 	web->output.fd = open(path, O_RDONLY);
 	if (web->output.fd == -1) {
+		DEBUG(0,("Failed to read file %s - %s\n", path, strerror(errno)));
 		http_error_unix(web, path);
 		return;
 	}
@@ -394,9 +397,6 @@ static void http_simple_request(struct websrv_context *web)
 		goto invalid;
 	}
 
-	http_output_headers(web);
-	EVENT_FD_WRITEABLE(web->conn->event.fde);
-	web->output.output_pending = True;
 	return;
 
 invalid:
@@ -481,16 +481,13 @@ void ejs_exception(const char *reason)
 /*
   process a esp request
 */
-static void esp_request(struct esp_state *esp)
+static void esp_request(struct esp_state *esp, const char *url)
 {
 	struct websrv_context *web = esp->web;
-	const char *url = web->input.url;
 	size_t size;
 	int res;
 	char *emsg = NULL, *buf;
 
-	http_setup_arrays(esp);
-
 	if (http_readFile(web, &buf, &size, url) != 0) {
 		http_error_unix(web, url);
 		return;
@@ -507,9 +504,40 @@ static void esp_request(struct esp_state *esp)
 		http_writeBlock(web, emsg, strlen(emsg));
 	}
 	talloc_free(buf);
-	http_output_headers(web);
-	EVENT_FD_WRITEABLE(web->conn->event.fde);
-	web->output.output_pending = True;
+}
+
+
+/*
+  perform pre-authentication on every page is /scripting/preauth.esp
+  exists.  If this script generates any non-whitepace output at all,
+  then we don't run the requested URL.
+
+  note that the preauth is run even for static pages such as images.
+*/
+static BOOL http_preauth(struct esp_state *esp)
+{
+	const char *path = http_local_path(esp->web, HTTP_PREAUTH_URI);
+	int i;
+	if (path == NULL) {
+		http_error(esp->web, 500, "Internal server error");
+		return False;
+	}
+	if (!file_exist(path)) {
+		/* if the preath script is not installed then allow access */
+		return True;
+	}
+	esp_request(esp, HTTP_PREAUTH_URI);
+	for (i=0;i<esp->web->output.content.length;i++) {
+		if (!isspace(esp->web->output.content.data[i])) {
+			/* if the preauth has generated content, then force it to be
+			   html, so that we can show the login page for failed
+			   access to images */
+			http_setHeader(esp->web, "Content-Type: text/html", 0);
+			return False;
+		}
+	}
+	data_blob_free(&esp->web->output.content);
+	return True;
 }
 
 
@@ -716,6 +744,7 @@ void http_process_input(struct websrv_context *web)
 		{"jpg",  "image/jpeg"},
 		{"txt",  "text/plain"},
 		{"ico",  "image/x-icon"},
+		{"css",  "text/css"},
 		{"esp",  "text/html", True}
 	};
 
@@ -798,10 +827,21 @@ void http_process_input(struct websrv_context *web)
 	http_setHeader(web, "Connection: close", 0);
 	http_setHeader(web, talloc_asprintf(esp, "Content-Type: %s", file_type), 0);
 
-	if (esp_enable) {
-		esp_request(esp);
-	} else {
-		http_simple_request(web);
+	http_setup_arrays(esp);
+
+	/* possibly do pre-authentication */
+	if (http_preauth(esp)) {
+		if (esp_enable) {
+			esp_request(esp, web->input.url);
+		} else {
+			http_simple_request(web);
+		}
+	}
+
+	if (!web->output.output_pending) {
+		http_output_headers(web);
+		EVENT_FD_WRITEABLE(web->conn->event.fde);
+		web->output.output_pending = True;
 	}
 
 	/* copy any application data to long term storage in edata */