This patch also refactors the if condition that checks the result of
the authentication since that has become quite unreadable. It renames
s1/s2 and extracts some parts of the condition into individual variables
to make the condition better understandle
Patch V2: add refactoring of the if condition
Signed-off-by: Arne Schwabe <a...@rfc2549.org>
---
Changes.rst | 12 ++++
doc/man-sections/script-options.rst | 14 ++++-
src/openvpn/ssl.c | 2 -
src/openvpn/ssl_verify.c | 86 +++++++++++++++++++++--------
4 files changed, 89 insertions(+), 25 deletions(-)
diff --git a/Changes.rst b/Changes.rst
index 2a2829e7..188bd8ab 100644
--- a/Changes.rst
+++ b/Changes.rst
@@ -9,6 +9,18 @@ Keying Material Exporters (RFC 5705) based key generation
the RFC5705 based key material generation to the current custom
OpenVPN PRF. This feature requires OpenSSL or mbed TLS 2.18+.
+Deferred auth support for scripts
+ The ``--auth-user-pass-verify`` script supports now deferred
authentication.
+
+Pending auth support for plugins and scripts
+ Both auth plugin and script can now signal pending authentication to
+ the client when using deferred authentication. The new
``client-crresponse``
+ script option and ``OPENVPN_PLUGIN_CLIENT_CRRESPONSE`` plugin function can
+ be used to parse a client response to a ``CR_TEXT`` two factor challenge.
+
+ See ``sample/sample-scripts/totpauth.py`` for an example.
+
+
Overview of changes in 2.5
==========================
diff --git a/doc/man-sections/script-options.rst
b/doc/man-sections/script-options.rst
index 03b3dd77..50edd986 100644
--- a/doc/man-sections/script-options.rst
+++ b/doc/man-sections/script-options.rst
@@ -90,7 +90,19 @@ SCRIPT HOOKS
The script should examine the username and password, returning a success
exit code (:code:`0`) if the client's authentication request is to be
- accepted, or a failure code (:code:`1`) to reject the client.
+ accepted, a failure code (:code:`1`) to reject the client, or a that
+ the authentication is deferred (:code:`2`). If the authentication is
+ deferred, the script must fork/start a background or another non-blocking
+ operation to continue the authentication in the background. When finshing
+ the authentication, a :code:`1` or :code:`0` must be written to the
+ file specified by the :code:`auth_control_file`.
+
+ When deferred authentication is in use, the script can also request
+ pending authentication by writing to the file specified by the
+ :code:`auth_pending_file`. The first line must be the timeout in
+ seconds and the second line the EXTRA as documented in the
+ ``client-pending-auth`` section of `doc/management.txt`.
+
This directive is designed to enable a plugin-style interface for
extending OpenVPN's authentication capabilities.
diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
index b8e77f0e..699b7347 100644
--- a/src/openvpn/ssl.c
+++ b/src/openvpn/ssl.c
@@ -992,9 +992,7 @@ key_state_free(struct key_state *ks, bool clear)
packet_id_free(&ks->crypto_options.packet_id);
-#ifdef PLUGIN_DEF_AUTH
key_state_rm_auth_control_files(ks);
-#endif
if (clear)
{
diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c
index b9647c1a..fc9f1d2e 100644
--- a/src/openvpn/ssl_verify.c
+++ b/src/openvpn/ssl_verify.c
@@ -1188,14 +1188,14 @@ tls_authenticate_key(struct tls_multi *multi, const
unsigned int mda_key_id, con
/*
* Verify the user name and password using a script
*/
-static bool
+static int
verify_user_pass_script(struct tls_session *session, struct tls_multi *multi,
const struct user_pass *up)
{
struct gc_arena gc = gc_new();
struct argv argv = argv_new();
const char *tmp_file = "";
- bool ret = false;
+ int retval = OPENVPN_PLUGIN_FUNC_ERROR;
/* Set environmental variables prior to calling script */
setenv_str(session->opt->es, "script_type", "user-pass-verify");
@@ -1223,25 +1223,61 @@ verify_user_pass_script(struct tls_session *session,
struct tls_multi *multi,
/* pass temp file name to script */
argv_printf_cat(&argv, "%s", tmp_file);
}
- else
- {
- msg(D_TLS_ERRORS, "TLS Auth Error: could not create write "
- "username/password to temp file");
- }
}
else
{
+ setenv_str(session->opt->es, "username", up->username);
setenv_str(session->opt->es, "password", up->password);
}
+ /* generate filename for deferred auth control file */
+ if (!key_state_gen_auth_control_files(&session->key[KS_PRIMARY],
+ session->opt))
+ {
+ msg(D_TLS_ERRORS, "TLS Auth Error (%s): "
+ "could not create deferred auth control file",
__func__);
+ return OPENVPN_PLUGIN_FUNC_ERROR;
+ }
+
/* call command */
- ret = openvpn_run_script(&argv, session->opt->es, 0,
- "--auth-user-pass-verify");
+ int script_ret = openvpn_run_script(&argv, session->opt->es, S_EXITCODE,
+ "--auth-user-pass-verify");
+ switch (script_ret)
+ {
+ case 0:
+ retval = OPENVPN_PLUGIN_FUNC_SUCCESS;
+ break;
+ case 2:
+ retval = OPENVPN_PLUGIN_FUNC_DEFERRED;
+ break;
+ default:
+ retval = OPENVPN_PLUGIN_FUNC_ERROR;
+ break;
+ }
+#ifdef ENABLE_DEF_AUTH
+ if (retval == OPENVPN_PLUGIN_FUNC_DEFERRED)
+ {
+ /* Check if we the plugin has written the pending auth control
+ * file and send the pending auth to the client */
+ if(!key_state_check_auth_pending_file(&session->key[KS_PRIMARY],
+ multi))
+ {
+ retval = OPENVPN_PLUGIN_FUNC_ERROR;
+ key_state_rm_auth_control_files(&session->key[KS_PRIMARY]);
+ }
+ }
+ else
+ {
+ /* purge auth control filename (and file itself) for non-deferred
returns */
+ key_state_rm_auth_control_files(&session->key[KS_PRIMARY]);
+ }
+#endif
if (!session->opt->auth_user_pass_verify_script_via_file)
{
setenv_del(session->opt->es, "password");
}
+
done:
if (tmp_file && strlen(tmp_file) > 0)
{
@@ -1250,7 +1286,7 @@ done:
argv_free(&argv);
gc_free(&gc);
- return ret;
+ return retval;
}
/*
@@ -1371,8 +1407,6 @@ void
verify_user_pass(struct user_pass *up, struct tls_multi *multi,
struct tls_session *session)
{
- int s1 = OPENVPN_PLUGIN_FUNC_SUCCESS;
- bool s2 = true;
struct key_state *ks = &session->key[KS_PRIMARY]; /* primary key */
#ifdef ENABLE_MANAGEMENT
@@ -1432,30 +1466,32 @@ verify_user_pass(struct user_pass *up, struct tls_multi
*multi,
}
}
+ int plugin_status = OPENVPN_PLUGIN_FUNC_SUCCESS;
+ int script_status = OPENVPN_PLUGIN_FUNC_SUCCESS;
/* Set the environment variables used by all auth variants */
if (!set_verify_user_pass_env(up, multi, session))
{
skip_auth = true;
- s1 = OPENVPN_PLUGIN_FUNC_ERROR;
+ plugin_status = OPENVPN_PLUGIN_FUNC_ERROR;
}
/* call plugin(s) and/or script */
if (!skip_auth)
{
#ifdef ENABLE_MANAGEMENT
- if (man_def_auth==KMDA_DEF)
+ if (man_def_auth == KMDA_DEF)
{
man_def_auth = verify_user_pass_management(session, multi, up);
}
#endif
if (plugin_defined(session->opt->plugins,
OPENVPN_PLUGIN_AUTH_USER_PASS_VERIFY))
{
- s1 = verify_user_pass_plugin(session, multi, up);
+ plugin_status = verify_user_pass_plugin(session, multi, up);
}
if (session->opt->auth_user_pass_verify_script)
{
- s2 = verify_user_pass_script(session, multi, up);
+ script_status = verify_user_pass_script(session, multi, up);
}
}
@@ -1466,19 +1502,25 @@ verify_user_pass(struct user_pass *up, struct tls_multi
*multi,
msg(D_TLS_ERRORS,
"TLS Auth Error: --username-as-common name specified and username
is longer than the maximum permitted Common Name length of %d characters",
TLS_USERNAME_LEN);
- s1 = OPENVPN_PLUGIN_FUNC_ERROR;
+ plugin_status = OPENVPN_PLUGIN_FUNC_ERROR;
+ script_status = OPENVPN_PLUGIN_FUNC_ERROR;
}
/* auth succeeded? */
- if ((s1 == OPENVPN_PLUGIN_FUNC_SUCCESS
- || s1 == OPENVPN_PLUGIN_FUNC_DEFERRED
- ) && s2
+ bool plugin_ok = plugin_status == OPENVPN_PLUGIN_FUNC_SUCCESS
+ || plugin_status == OPENVPN_PLUGIN_FUNC_DEFERRED;
+
+ bool script_ok = script_status == OPENVPN_PLUGIN_FUNC_SUCCESS
+ || script_status == OPENVPN_PLUGIN_FUNC_DEFERRED;
+
+ if (script_ok && plugin_ok && tls_lock_username(multi, up->username)
#ifdef ENABLE_MANAGEMENT
&& man_def_auth != KMDA_ERROR
#endif
- && tls_lock_username(multi, up->username))
+ )
{
ks->authenticated = KS_AUTH_TRUE;
- if (s1 == OPENVPN_PLUGIN_FUNC_DEFERRED)
+ if (plugin_status == OPENVPN_PLUGIN_FUNC_DEFERRED
+ || script_status == OPENVPN_PLUGIN_FUNC_DEFERRED)
{
ks->authenticated = KS_AUTH_DEFERRED;
}
--
2.30.0
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