# HG changeset patch
# User Maxim Dounin <mdounin@mdounin.ru>
# Date 1266665430 -10800
# Node ID 436da5355bd5f50d680e3ef094bfa40138443203

Auth request module.

diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,24 @@
+/* 
+ * Copyright (C) 2010 Maxim Dounin
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
diff --git a/README b/README
new file mode 100644
--- /dev/null
+++ b/README
@@ -0,0 +1,34 @@
+Auth request module for nginx.
+
+This module allows authorization based on subrequest result.  Once subrequest
+returns 2xx status - access is allowed, on 401 or 403 - disabled with
+appropriate status.  Anything else is considered to be an error.
+
+For 401 status WWW-Authenticate header from subrequest response will be
+passed to client.
+
+Configuration directives:
+
+    auth_request <uri>|off
+
+        Context: http, server, location
+        Default: off
+
+        Switches auth request module on and sets uri which will be asked for
+        authorization.
+
+Usage:
+
+    location /private/ {
+        auth_request /auth;
+        ...
+    }
+
+    location = /auth {
+        proxy_pass ...
+    }
+
+To compile nginx with auth request module, use "--add-module <path>" option
+to nginx configure.
+
+Development of this module was sponsored by Openstat (http://www.openstat.com/).
diff --git a/config b/config
new file mode 100644
--- /dev/null
+++ b/config
@@ -0,0 +1,10 @@
+# (C) Maxim Dounin
+# Configuration for ngx_http_auth_request_module.
+
+ngx_addon_name="ngx_http_auth_request_module"
+
+HTTP_MODULES="$HTTP_MODULES \
+		ngx_http_auth_request_module"
+
+NGX_ADDON_SRCS="$NGX_ADDON_SRCS \
+		$ngx_addon_dir/ngx_http_auth_request_module.c"
diff --git a/ngx_http_auth_request_module.c b/ngx_http_auth_request_module.c
new file mode 100644
--- /dev/null
+++ b/ngx_http_auth_request_module.c
@@ -0,0 +1,233 @@
+
+/*
+ * Copyright (C) Maxim Dounin
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+#include <ngx_http.h>
+
+
+typedef struct {
+    ngx_str_t                 uri;
+} ngx_http_auth_request_conf_t;
+
+typedef struct {
+    ngx_uint_t                done;
+    ngx_uint_t                status;
+    ngx_http_request_t       *subrequest;
+} ngx_http_auth_request_ctx_t;
+
+
+static ngx_int_t ngx_http_auth_request_handler(ngx_http_request_t *r);
+static ngx_int_t ngx_http_auth_request_done(ngx_http_request_t *r,
+    void *data, ngx_int_t rc);
+static void *ngx_http_auth_request_create_conf(ngx_conf_t *cf);
+static char *ngx_http_auth_request_merge_conf(ngx_conf_t *cf,
+    void *parent, void *child);
+static ngx_int_t ngx_http_auth_request_init(ngx_conf_t *cf);
+
+
+static ngx_command_t  ngx_http_auth_request_commands[] = {
+
+    { ngx_string("auth_request"),
+      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
+      ngx_conf_set_str_slot,
+      NGX_HTTP_LOC_CONF_OFFSET,
+      offsetof(ngx_http_auth_request_conf_t, uri),
+      NULL },
+
+      ngx_null_command
+};
+
+
+static ngx_http_module_t  ngx_http_auth_request_module_ctx = {
+    NULL,                                  /* preconfiguration */
+    ngx_http_auth_request_init,            /* postconfiguration */
+
+    NULL,                                  /* create main configuration */
+    NULL,                                  /* init main configuration */
+
+    NULL,                                  /* create server configuration */
+    NULL,                                  /* merge server configuration */
+
+    ngx_http_auth_request_create_conf,     /* create location configuration */
+    ngx_http_auth_request_merge_conf       /* merge location configuration */
+};
+
+
+ngx_module_t  ngx_http_auth_request_module = {
+    NGX_MODULE_V1,
+    &ngx_http_auth_request_module_ctx,     /* module context */
+    ngx_http_auth_request_commands,        /* module directives */
+    NGX_HTTP_MODULE,                       /* module type */
+    NULL,                                  /* init master */
+    NULL,                                  /* init module */
+    NULL,                                  /* init process */
+    NULL,                                  /* init thread */
+    NULL,                                  /* exit thread */
+    NULL,                                  /* exit process */
+    NULL,                                  /* exit master */
+    NGX_MODULE_V1_PADDING
+};
+
+
+static ngx_int_t
+ngx_http_auth_request_handler(ngx_http_request_t *r)
+{
+    ngx_table_elt_t               *h, *ho;
+    ngx_http_request_t            *sr;
+    ngx_http_post_subrequest_t    *ps;
+    ngx_http_auth_request_ctx_t   *ctx;
+    ngx_http_auth_request_conf_t  *arcf;
+
+    arcf = ngx_http_get_module_loc_conf(r, ngx_http_auth_request_module);
+
+    if (arcf->uri.len == 0) {
+        return NGX_DECLINED;
+    }
+
+    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "auth request handler");
+
+    ctx = ngx_http_get_module_ctx(r, ngx_http_auth_request_module);
+
+    if (ctx != NULL) {
+        if (!ctx->done) {
+            return NGX_AGAIN;
+        }
+
+        if (ctx->status == NGX_HTTP_FORBIDDEN) {
+            return ctx->status;
+        }
+
+        if (ctx->status == NGX_HTTP_UNAUTHORIZED) {
+            sr = ctx->subrequest;
+
+            h = sr->headers_out.www_authenticate;
+
+            if (!h && sr->upstream) {
+                h = sr->upstream->headers_in.www_authenticate;
+            }
+
+            if (h) {
+                ho = ngx_list_push(&r->headers_out.headers);
+                if (ho == NULL) {
+                    return NGX_ERROR;
+                }
+
+                *ho = *h;
+
+                r->headers_out.www_authenticate = ho;
+            }
+
+            return ctx->status;
+        }
+
+        if (ctx->status >= NGX_HTTP_OK
+            && ctx->status < NGX_HTTP_SPECIAL_RESPONSE)
+        {
+            return NGX_OK;
+        }
+
+        ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                      "auth request unexpected status: %d", ctx->status);
+
+        return NGX_HTTP_INTERNAL_SERVER_ERROR;
+    }
+
+    ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_auth_request_ctx_t));
+    if (ctx == NULL) {
+        return NGX_ERROR;
+    }
+
+    ps = ngx_palloc(r->pool, sizeof(ngx_http_post_subrequest_t));
+    if (ps == NULL) {
+        return NGX_ERROR;
+    }
+
+    ps->handler = ngx_http_auth_request_done;
+    ps->data = ctx;
+
+    if (ngx_http_subrequest(r, &arcf->uri, NULL, &sr, ps,
+                            NGX_HTTP_SUBREQUEST_WAITED)
+        != NGX_OK)
+    {
+        return NGX_ERROR;
+    }
+
+    sr->header_only = 1;
+
+    ctx->subrequest = sr;
+
+    ngx_http_set_ctx(r, ctx, ngx_http_auth_request_module);
+
+    return NGX_AGAIN;
+}
+
+
+static ngx_int_t
+ngx_http_auth_request_done(ngx_http_request_t *r, void *data, ngx_int_t rc)
+{
+    ngx_http_auth_request_ctx_t   *ctx = data;
+
+    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+                   "auth request done s:%d", r->headers_out.status);
+
+    ctx->done = 1;
+    ctx->status = r->headers_out.status;
+
+    return rc;
+}
+
+
+static void *
+ngx_http_auth_request_create_conf(ngx_conf_t *cf)
+{
+    ngx_http_auth_request_conf_t  *conf;
+
+    conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_auth_request_conf_t));
+    if (conf == NULL) {
+        return NULL;
+    }
+
+    /*
+     * set by ngx_pcalloc():
+     *
+     *     conf->uri.len = { 0, NULL };
+     */
+
+    return conf;
+}
+
+
+static char *
+ngx_http_auth_request_merge_conf(ngx_conf_t *cf, void *parent, void *child)
+{
+    ngx_http_auth_request_conf_t *prev = parent;
+    ngx_http_auth_request_conf_t *conf = child;
+
+    ngx_conf_merge_str_value(conf->uri, prev->uri, "");
+
+    return NGX_CONF_OK;
+}
+
+
+static ngx_int_t
+ngx_http_auth_request_init(ngx_conf_t *cf)
+{
+    ngx_http_handler_pt        *h;
+    ngx_http_core_main_conf_t  *cmcf;
+
+    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);
+
+    h = ngx_array_push(&cmcf->phases[NGX_HTTP_ACCESS_PHASE].handlers);
+    if (h == NULL) {
+        return NGX_ERROR;
+    }
+
+    *h = ngx_http_auth_request_handler;
+
+    return NGX_OK;
+}
diff --git a/t/auth-request.t b/t/auth-request.t
new file mode 100644
--- /dev/null
+++ b/t/auth-request.t
@@ -0,0 +1,163 @@
+#!/usr/bin/perl
+
+# (C) Maxim Dounin
+
+# Tests for auth request module.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+my $t = Test::Nginx->new()->has(qw/http rewrite proxy fastcgi auth_basic/)
+	->plan(13);
+
+$t->write_file_expand('nginx.conf', <<'EOF');
+
+master_process off;
+daemon         off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location / {
+            return 444;
+        }
+
+        location /open {
+            auth_request /auth-open;
+        }
+        location = /auth-open {
+            return 204;
+        }
+
+        location /open-static {
+            auth_request /auth-open-static;
+        }
+        location = /auth-open-static {
+            # nothing, use static file
+        }
+
+        location /unauthorized {
+            auth_request /auth-unauthorized;
+        }
+        location = /auth-unauthorized {
+            return 401;
+        }
+
+        location /forbidden {
+            auth_request /auth-forbidden;
+        }
+        location = /auth-forbidden {
+            return 403;
+        }
+
+        location /error {
+            auth_request /auth-error;
+        }
+        location = /auth-error {
+            return 404;
+        }
+
+        location /proxy {
+            auth_request /auth-proxy;
+        }
+        location = /auth-proxy {
+            proxy_pass http://127.0.0.1:8080/auth-basic;
+        }
+        location = /auth-basic {
+            auth_basic "restricted";
+            auth_basic_user_file %%TESTDIR%%/htpasswd;
+        }
+
+        location /fastcgi {
+            auth_request /auth-fastcgi;
+        }
+        location = /auth-fastcgi {
+            fastcgi_pass 127.0.0.1:8081;
+        }
+    }
+}
+
+EOF
+
+$t->write_file('htpasswd', 'user:zz1T8N4tWvmbE' . "\n");
+$t->write_file('auth-basic', 'INVISIBLE');
+$t->write_file('auth-open-static', 'INVISIBLE');
+$t->run();
+
+###############################################################################
+
+pass('runs');
+
+like(http_get('/open'), qr/ 404 /, 'auth open');
+like(http_get('/unauthorized'), qr/ 401 /, 'auth unauthorized');
+like(http_get('/forbidden'), qr/ 403 /, 'auth forbidden');
+like(http_get('/error'), qr/ 500 /, 'auth error');
+
+like(http_get('/open-static'), qr/ 404 /, 'auth open static');
+unlike(http_get('/open-static'), qr/INVISIBLE/, 'auth static no content');
+
+like(http_get('/proxy'), qr/ 401 /, 'proxy auth unauthorized');
+like(http_get('/proxy'), qr/WWW-Authenticate: Basic realm="restricted"/,
+	'proxy auth has www-authenticate');
+like(http_get_auth('/proxy'), qr/ 404 /, 'proxy auth pass');
+unlike(http_get_auth('/proxy'), qr/INVISIBLE/, 'proxy auth no content');
+
+SKIP: {
+	eval { require FCGI; };
+	skip 'FCGI not installed', 2 if $@;
+
+	$t->run_daemon(\&fastcgi_daemon);
+	$t->waitforsocket('127.0.0.1:8081');
+
+	like(http_get('/fastcgi'), qr/ 404 /, 'fastcgi auth open');
+	unlike(http_get('/fastcgi'), qr/INVISIBLE/, 'fastcgi auth no content');
+}
+
+###############################################################################
+
+sub http_get_auth {
+        my ($url, %extra) = @_;
+        return http(<<EOF, %extra);
+GET $url HTTP/1.0
+Host: localhost
+Authorization: Basic dXNlcjpzZWNyZXQ=
+
+EOF
+}
+
+###############################################################################
+
+sub fastcgi_daemon {
+	my $socket = FCGI::OpenSocket('127.0.0.1:8081', 5);
+	my $request = FCGI::Request(\*STDIN, \*STDOUT, \*STDERR, \%ENV,
+		$socket);
+
+	while ($request->Accept() >= 0) {
+		print <<EOF;
+Content-Type: text/html
+
+INVISIBLE
+EOF
+	}
+
+	FCGI::CloseSocket($socket);
+}
+
+###############################################################################