From 4ca0e1483d64bde0123a461f575ca78473677725 Mon Sep 17 00:00:00 2001 From: Daniel Kubec Date: Sun, 5 Apr 2015 00:10:37 +0200 Subject: [PATCH] Added Sample HTTP (SSO) Plugin based on TLS Keying Material Exporters [RFC-5705] --- sample/sample-plugins/sso/README | 62 +++++++ sample/sample-plugins/sso/build | 15 ++ sample/sample-plugins/sso/client.ovpn | 17 ++ sample/sample-plugins/sso/http-client.py | 21 +++ sample/sample-plugins/sso/http-server.py | 41 +++++ sample/sample-plugins/sso/server.ovpn | 19 ++ sample/sample-plugins/sso/sso.c | 269 ++++++++++++++++++++++++++++++ 7 files changed, 444 insertions(+), 0 deletions(-) create mode 100644 sample/sample-plugins/sso/README create mode 100755 sample/sample-plugins/sso/build create mode 100644 sample/sample-plugins/sso/client.ovpn create mode 100755 sample/sample-plugins/sso/http-client.py create mode 100755 sample/sample-plugins/sso/http-server.py create mode 100644 sample/sample-plugins/sso/server.ovpn create mode 100644 sample/sample-plugins/sso/sso.c diff --git a/sample/sample-plugins/sso/README b/sample/sample-plugins/sso/README new file mode 100644 index 0000000..27c3b08 --- /dev/null +++ b/sample/sample-plugins/sso/README @@ -0,0 +1,62 @@ +OpenVPN plugin examples. Daniel Kubec + +Examples provided: + +sso.c -- HTTP (SSO) Example based on TLS Keying Material Exporters [RFC-5705] + (openvpn/doc/keying-material-exporter.txt) + +Requires: +OpenVPN RFC-5705 Support, OpenSSL >= 1.0.1 + +Files: + http-server.py -- Example HTTP Server listen 0.0.0.0:8080 + http-client.py -- Example HTTP Client connect 10.8.0.1:8080 [GET /$SESSIONID] + + server.ovpn -- Example HTTP SSO VPN Server configuration + client.ovpn -- Example HTTP SSO VPN Client configuration + + sso.c, sso.so -- Example OpenVPN Client and Server plugin + +To build: + ./build sso + +To use in OpenVPN: + +Enter openvpn/sample/sample-plugins/sso directory + +$ openvpn --config ./server.ovpn +$ openvpn --config ./client.ovpn +$ ./http-server.py +$ ./http-client.py + +Test: + +openvpn --config ./server.ovpn +############################## + +PLUGIN SSO: app session created +PLUGIN_CALL: POST ./sso.so/PLUGIN_TLS_VERIFY status=0 +PLUGIN SSO: app session key: a5885abc84d361803f58ede1ef9c0adf99e720cd +PLUGIN SSO: app session file: /tmp/openvpn_sso_a5885abc84d361803f58ede1ef9c0adf99e720cd +PLUGIN SSO: app session user: Test-Client + +openvpn --config ./client.ovpn +############################## +PLUGIN SSO: app session created +PLUGIN_CALL: POST ./sso.so/PLUGIN_TLS_VERIFY status=0 +PLUGIN SSO: app session key: a5885abc84d361803f58ede1ef9c0adf99e720cd +PLUGIN SSO: app session file: /tmp/openvpn_sso_user +PLUGIN_CALL: POST ./sso.so/PLUGIN_TLS_FINAL status=0 + +HTTP_SERVER: +http-server.py +################ +http server started +session file: /tmp/openvpn_sso_a5885abc84d361803f58ede1ef9c0adf99e720cd +10.8.0.1 - - [02/Apr/2015 15:03:33] "GET /a5885abc84d361803f58ede1ef9c0adf99e720cd HTTP/1.1" 200 - +session user: Test-Client +session key: a5885abc84d361803f58ede1ef9c0adf99e720cd + +HTTP_SERVER: +http-client.py +

Greetings Test-Client. You are authorized

diff --git a/sample/sample-plugins/sso/build b/sample/sample-plugins/sso/build new file mode 100755 index 0000000..bbb05f7 --- /dev/null +++ b/sample/sample-plugins/sso/build @@ -0,0 +1,15 @@ +#!/bin/sh + +# +# Build an OpenVPN plugin module on *nix. The argument should +# be the base name of the C source file (without the .c). +# + +# This directory is where we will look for openvpn-plugin.h +CPPFLAGS="${CPPFLAGS:--I../../..}" + +CC="${CC:-gcc}" +CFLAGS="${CFLAGS:--O2 -Wall -g}" + +$CC $CPPFLAGS $CFLAGS -fPIC -c $1.c && \ +$CC $CFLAGS -fPIC -shared $LDFLAGS -Wl,-soname,$1.so -o $1.so $1.o -lc diff --git a/sample/sample-plugins/sso/client.ovpn b/sample/sample-plugins/sso/client.ovpn new file mode 100644 index 0000000..b8e0a6b --- /dev/null +++ b/sample/sample-plugins/sso/client.ovpn @@ -0,0 +1,17 @@ +tls-client + +keying-material-exporter "EXPORTER_SSO_TEST" 16 +reneg-sec 0 + +ca ../../sample-keys/ca.crt +cert ../../sample-keys/client.crt +key ../../sample-keys/client.key + +plugin ./sso.so + +remote 127.0.0.1 1194 +proto udp +dev tun +nobind + +verb 4 diff --git a/sample/sample-plugins/sso/http-client.py b/sample/sample-plugins/sso/http-client.py new file mode 100755 index 0000000..487b029 --- /dev/null +++ b/sample/sample-plugins/sso/http-client.py @@ -0,0 +1,21 @@ +#!/usr/bin/python +import sys +import os +import httplib + +f = '/tmp/openvpn_sso_user' +with open (f, "r") as myfile: + session_key = myfile.read().replace('\n', '') + +conn = httplib.HTTPConnection("10.8.0.1:8080") +conn.request("GET", "/" + session_key) +r1 = conn.getresponse() + +if r1.status == 200: + body = r1.read().rstrip() + print body +elif r1.status == 404: + print "Authentication failed" +else: + print r1.status, r1.reason + diff --git a/sample/sample-plugins/sso/http-server.py b/sample/sample-plugins/sso/http-server.py new file mode 100755 index 0000000..0b685cf --- /dev/null +++ b/sample/sample-plugins/sso/http-server.py @@ -0,0 +1,41 @@ +#!/usr/bin/python +from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer +import os + +class ExampleHTTPRequestHandler(BaseHTTPRequestHandler): + + def do_GET(self): + session_key = os.path.basename(self.path) + file = '/tmp/openvpn_sso_' + session_key + print 'session file: ' + file + try: + f = open(file) + #send code 200 response + self.send_response(200) + #send header first + self.send_header('Content-type','text-html') + self.end_headers() + #send file content to client + user = f.read().rstrip() + print 'session user: ' + user + print 'session key: ' + session_key + self.wfile.write('

Greetings ' + user \ + + '. You are authorized' \ + '

' \ + '') + f.close() + return + except IOError: + self.send_error(404, 'authentication failed') + +def run(): + #ip and port of servr + #by default http server port is 80 + server_address = ('0.0.0.0', 8080) + httpd = HTTPServer(server_address, ExampleHTTPRequestHandler) + print('http server started') + httpd.serve_forever() + print('http server stopped') + +if __name__ == '__main__': + run() diff --git a/sample/sample-plugins/sso/server.ovpn b/sample/sample-plugins/sso/server.ovpn new file mode 100644 index 0000000..e9a8711 --- /dev/null +++ b/sample/sample-plugins/sso/server.ovpn @@ -0,0 +1,19 @@ +tls-server +reneg-sec 0 + +keying-material-exporter "EXPORTER_SSO_TEST" 16 +duplicate-cn + +plugin ./sso.so +ca ../../sample-keys/ca.crt +cert ../../sample-keys/server.crt +key ../../sample-keys/server.key +dh ../../sample-keys/dh2048.pem + +server 10.8.0.0 255.255.255.0 +port 1194 +proto udp +dev tun + +verb 4 + diff --git a/sample/sample-plugins/sso/sso.c b/sample/sample-plugins/sso/sso.c new file mode 100644 index 0000000..b0d77ea --- /dev/null +++ b/sample/sample-plugins/sso/sso.c @@ -0,0 +1,269 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2010 OpenVPN Technologies, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program (see the file COPYING included with this + * distribution); if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* + * This file implements a Sample (HTTP) SSO OpenVPN plugin module + * + * See the README file for build instructions. + */ + +#define ENABLE_CRYPTO + +#include +#include +#include + +#include "openvpn-plugin.h" + +#ifndef MAXPATH +#define MAXPATH 1024 +#endif + +#define ovpn_err(fmt, ...) \ + plugin->log(PLOG_ERR, "SSO", fmt , ## __VA_ARGS__) +#define ovpn_dbg(fmt, ...) \ + plugin->log(PLOG_DEBUG, "SSO", fmt , ## __VA_ARGS__) +#define ovpn_note(fmt, ...) \ + plugin->log(PLOG_NOTE, "SSO", fmt , ## __VA_ARGS__) + +enum endpoint { CLIENT = 1, SERVER = 2 }; + +struct plugin { + plugin_log_t log; + enum endpoint type; + int mask; +}; + +struct session { + char user[48]; + char key [48]; +}; + +/* + * Given an environmental variable name, search + * the envp array for its value, returning it + * if found or NULL otherwise. + */ + +static const char * +get_env(const char *name, const char *envp[]) +{ + if (envp) + { + int i; + const int namelen = strlen (name); + for (i = 0; envp[i]; ++i) + { + if (!strncmp (envp[i], name, namelen)) + { + const char *cp = envp[i] + namelen; + if (*cp == '=') + return cp + 1; + } + } + } + return NULL; +} + +OPENVPN_EXPORT int +openvpn_plugin_open_v3 (const int version, + struct openvpn_plugin_args_open_in const *args, + struct openvpn_plugin_args_open_return *rv) +{ + struct plugin *plugin = calloc (1, sizeof(*plugin)); + + plugin->type = get_env ("remote_1", args->envp) ? CLIENT : SERVER; + plugin->log = args->callbacks->plugin_log; + + plugin->mask = OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_TLS_FINAL); + plugin->mask |= OPENVPN_PLUGIN_MASK(OPENVPN_PLUGIN_TLS_VERIFY); + + ovpn_note("vpn endpoint type=%s",plugin->type == CLIENT ? "client":"server"); + + rv->type_mask = plugin->mask; + rv->handle = (void *)plugin; + + return OPENVPN_PLUGIN_FUNC_SUCCESS; +} + +static void +session_user_set(struct session *sess, X509 *x509) +{ + int fn_nid; + ASN1_OBJECT *fn; + ASN1_STRING *val; + X509_NAME *x509_name; + X509_NAME_ENTRY *ent; + const char *objbuf; + + x509_name = X509_get_subject_name (x509); + int i, n = X509_NAME_entry_count (x509_name); + for (i = 0; i < n; ++i) + { + if (!(ent = X509_NAME_get_entry (x509_name, i))) + continue; + if (!(fn = X509_NAME_ENTRY_get_object (ent))) + continue; + if (!(val = X509_NAME_ENTRY_get_data (ent))) + continue; + if ((fn_nid = OBJ_obj2nid (fn)) == NID_undef) + continue; + if (!(objbuf = OBJ_nid2sn (fn_nid))) + continue; + /* bug in OpenSSL 0.9.6b ASN1_STRING_to_UTF8 requires this workaround */ + unsigned char *buf = (unsigned char *)1; + if (ASN1_STRING_to_UTF8 (&buf, val) <= 0) + continue; + + if (!strncasecmp(objbuf, "CN", 2)) + snprintf(sess->user, sizeof(sess->user) - 1, (char *)buf); + + OPENSSL_free (buf); + } +} + +static int +tls_verify(struct openvpn_plugin_args_func_in const *args) +{ + struct plugin *plugin = (struct plugin *)args->handle; + struct session *sess = (struct session *)args->per_client_context; + + /* we store cert subject for the server end point only */ + if (plugin->type != SERVER) + return OPENVPN_PLUGIN_FUNC_SUCCESS; + + if (!args->current_cert) { + ovpn_err("this example plugin requires client certificate"); + return OPENVPN_PLUGIN_FUNC_ERROR; + } + + session_user_set(sess, args->current_cert); + + return OPENVPN_PLUGIN_FUNC_SUCCESS; +} + +static void +file_store(char *file, char *content) +{ + FILE *f; + if (!(f = fopen(file, "w+"))) + return; + + fprintf(f, "%s", content); + fclose(f); +} + +static void +server_store(struct openvpn_plugin_args_func_in const *args) +{ + struct plugin *plugin = (struct plugin *)args->handle; + struct session *sess = (struct session *)args->per_client_context; + + char file[MAXPATH]; + snprintf(file, sizeof(file) - 1, "/tmp/openvpn_sso_%s", sess->key); + ovpn_note("app session file: %s", file); + file_store(file, sess->user); +} + +static void +client_store(struct openvpn_plugin_args_func_in const *args) +{ + struct plugin *plugin = (struct plugin *)args->handle; + struct session *sess = (struct session *)args->per_client_context; + + char *file = "/tmp/openvpn_sso_user"; + ovpn_note("app session file: %s", file); + file_store(file, sess->key); +} + +static int +tls_final(struct openvpn_plugin_args_func_in const *args, + struct openvpn_plugin_args_func_return *rv) +{ + struct plugin *plugin = (struct plugin *)args->handle; + struct session *sess = (struct session *)args->per_client_context; + + const char *key; + if (!(key = get_env ("exported_keying_material", args->envp))) + return OPENVPN_PLUGIN_FUNC_ERROR; + + snprintf(sess->key, sizeof(sess->key) - 1, "%s", key); + ovpn_note("app session key: %s", sess->key); + + switch (plugin->type) { + case SERVER: + server_store(args); + break; + case CLIENT: + client_store(args); + return OPENVPN_PLUGIN_FUNC_SUCCESS; + } + + ovpn_note("app session user: %s", sess->user); + return OPENVPN_PLUGIN_FUNC_SUCCESS; +} + +OPENVPN_EXPORT int +openvpn_plugin_func_v3 (const int version, + struct openvpn_plugin_args_func_in const *args, + struct openvpn_plugin_args_func_return *rv) +{ + switch(args->type) { + case OPENVPN_PLUGIN_TLS_VERIFY: + return tls_verify(args); + case OPENVPN_PLUGIN_TLS_FINAL: + return tls_final(args, rv); + } + return OPENVPN_PLUGIN_FUNC_SUCCESS; +} + +OPENVPN_EXPORT void * +openvpn_plugin_client_constructor_v1(openvpn_plugin_handle_t handle) +{ + struct plugin *plugin = (struct plugin *)handle; + struct session *sess = calloc (1, sizeof(*sess)); + + ovpn_note("app session created"); + + return (void *)sess; +} + +OPENVPN_EXPORT void +openvpn_plugin_client_destructor_v1(openvpn_plugin_handle_t handle, void *ctx) +{ + struct plugin *plugin = (struct plugin *)handle; + struct session *sess = (struct session *)ctx; + + ovpn_note("app session key: %s", sess->key); + ovpn_note("app session destroyed"); + + free (sess); +} + +OPENVPN_EXPORT void +openvpn_plugin_close_v1 (openvpn_plugin_handle_t handle) +{ + struct plugin *plugin = (struct plugin *)handle; + free (plugin); +} -- 1.7.1