Hi,
Thanks for taking one more step towards simplifying this state jungle..
On 06/07/2020 18:35, Arne Schwabe wrote:
> Both are tightly coupled often both are checked at the same time.
> Merging them into one state makes the code simpler and also brings
> us closer in the direction of a state machine
>
> Signed-off-by: Arne Schwabe <a...@rfc2549.org>
> ---
> src/openvpn/ssl.c | 29 ++++++++++++-----------------
> src/openvpn/ssl_common.h | 9 +++++++--
> src/openvpn/ssl_verify.c | 27 ++++++++++++++-------------
> 3 files changed, 33 insertions(+), 32 deletions(-)
>
> diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c
> index 1cf8e44f..9df7552d 100644
> --- a/src/openvpn/ssl.c
> +++ b/src/openvpn/ssl.c
> @@ -1930,7 +1930,7 @@ tls_session_generate_data_channel_keys(struct
> tls_session *session)
> const struct session_id *server_sid = !session->opt->server ?
> &ks->session_id_remote :
> &session->session_id;
>
> - if (!ks->authenticated)
> + if (ks->authenticated == KS_AUTH_FALSE)
> {
> msg(D_TLS_ERRORS, "TLS Error: key_state not authenticated");
> goto cleanup;
> @@ -2466,7 +2466,7 @@ key_method_2_write(struct buffer *buf, struct
> tls_session *session)
> if (session->opt->server && !(session->opt->ncp_enabled
> && session->opt->mode == MODE_SERVER &&
> ks->key_id <= 0))
> {
> - if (ks->authenticated)
> + if (ks->authenticated != KS_AUTH_FALSE)
> {
> if (!tls_session_generate_data_channel_keys(session))
> {
> @@ -2536,7 +2536,7 @@ key_method_1_read(struct buffer *buf, struct
> tls_session *session)
> &session->opt->key_type, OPENVPN_OP_DECRYPT,
> "Data Channel Decrypt");
> secure_memzero(&key, sizeof(key));
> - ks->authenticated = true;
> + ks->authenticated = KS_AUTH_TRUE;
> return true;
>
> error:
> @@ -2594,7 +2594,7 @@ key_method_2_read(struct buffer *buf, struct tls_multi
> *multi, struct tls_sessio
> goto error;
> }
>
> - ks->authenticated = false;
> + ks->authenticated = KS_AUTH_FALSE;
>
> /* always extract username + password fields from buf, even if not
> * authenticating for it, because otherwise we can't get at the
> @@ -2652,14 +2652,14 @@ key_method_2_read(struct buffer *buf, struct
> tls_multi *multi, struct tls_sessio
> "TLS Error: Certificate verification failed (key-method 2)");
> goto error;
> }
> - ks->authenticated = true;
> + ks->authenticated = KS_AUTH_TRUE;
> }
>
> /* clear username and password from memory */
> secure_memzero(up, sizeof(*up));
>
> /* Perform final authentication checks */
> - if (ks->authenticated)
> + if (ks->authenticated != KS_AUTH_FALSE)
> {
> verify_final_auth_checks(multi, session);
> }
> @@ -2673,7 +2673,7 @@ key_method_2_read(struct buffer *buf, struct tls_multi
> *multi, struct tls_sessio
> if (session->opt->ssl_flags & SSLF_OPT_VERIFY)
> {
> msg(D_TLS_ERRORS, "Option inconsistency warnings triggering
> disconnect due to --opt-verify");
> - ks->authenticated = false;
> + ks->authenticated = KS_AUTH_FALSE;
> }
> }
> #endif
> @@ -2684,13 +2684,14 @@ key_method_2_read(struct buffer *buf, struct
> tls_multi *multi, struct tls_sessio
> * Call OPENVPN_PLUGIN_TLS_FINAL plugin if defined, for final
> * veto opportunity over authentication decision.
> */
> - if (ks->authenticated && plugin_defined(session->opt->plugins,
> OPENVPN_PLUGIN_TLS_FINAL))
> + if ((ks->authenticated != KS_AUTH_FALSE)
> + && plugin_defined(session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL))
> {
> key_state_export_keying_material(&ks->ks_ssl, session);
>
> if (plugin_call(session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL,
> NULL, NULL, session->opt->es) != OPENVPN_PLUGIN_FUNC_SUCCESS)
> {
> - ks->authenticated = false;
> + ks->authenticated = KS_AUTH_FALSE;
> }
>
> setenv_del(session->opt->es, "exported_keying_material");
> @@ -3394,10 +3395,7 @@ tls_pre_decrypt(struct tls_multi *multi,
> */
> if (DECRYPT_KEY_ENABLED(multi, ks)
> && key_id == ks->key_id
> - && ks->authenticated
> -#ifdef ENABLE_DEF_AUTH
> - && !ks->auth_deferred
> -#endif
> + && (ks->authenticated == KS_AUTH_TRUE)
> && (floated || link_socket_actual_match(from,
> &ks->remote_addr)))
> {
> if (!ks->crypto_options.key_ctx_bi.initialized)
> @@ -3946,11 +3944,8 @@ tls_pre_encrypt(struct tls_multi *multi,
> {
> struct key_state *ks = multi->key_scan[i];
> if (ks->state >= S_ACTIVE
> - && ks->authenticated
> + && (ks->authenticated == KS_AUTH_TRUE)
> && ks->crypto_options.key_ctx_bi.initialized
> -#ifdef ENABLE_DEF_AUTH
> - && !ks->auth_deferred
> -#endif
> )
> {
> if (!ks_select)
> diff --git a/src/openvpn/ssl_common.h b/src/openvpn/ssl_common.h
> index fe523362..fdf589b5 100644
> --- a/src/openvpn/ssl_common.h
> +++ b/src/openvpn/ssl_common.h
> @@ -127,6 +127,12 @@ struct key_source2 {
> struct key_source server; /**< Random provided by server. */
> };
>
> +enum ks_auth_state {
> + KS_AUTH_FALSE,
> + KS_AUTH_TRUE,
> + KS_AUTH_DEFERRED
how about wrapping KS_AUTH_DEFERRED within #ifdef ENABLE_DEF_AUTH for
now? This way we have a way to make sure this value is not used outside
of the ENABLE_DEF_AUTH context.
If the long term goal is to remove this define once and for all, I'd
suggest to then have a patch that removes all the instances. Or at least
to have a specific patch targeting that aspect.
> +};
> +
> /**
> * Security parameter state of one TLS and data channel %key session.
> * @ingroup control_processor
> @@ -185,12 +191,11 @@ struct key_state
> /*
> * If bad username/password, TLS connection will come up but
> 'authenticated' will be false.
> */
> - bool authenticated;
> + enum ks_auth_state authenticated;
> time_t auth_deferred_expire;
>
> #ifdef ENABLE_DEF_AUTH
> /* If auth_deferred is true, authentication is being deferred */
should this comment also go?
> - bool auth_deferred;
> #ifdef MANAGEMENT_DEF_AUTH
> unsigned int mda_key_id;
> unsigned int mda_status;
> diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c
> index 68c39c6f..e28f1f3a 100644
> --- a/src/openvpn/ssl_verify.c
> +++ b/src/openvpn/ssl_verify.c
> @@ -78,7 +78,7 @@ tls_deauthenticate(struct tls_multi *multi)
> {
> for (int j = 0; j < KS_SIZE; ++j)
> {
> - multi->session[i].key[j].authenticated = false;
> + multi->session[i].key[j].authenticated = KS_AUTH_FALSE;
> }
> }
> }
> @@ -950,7 +950,7 @@ tls_authentication_status(struct tls_multi *multi, const
> int latency)
> if (DECRYPT_KEY_ENABLED(multi, ks))
> {
> active = true;
> - if (ks->authenticated)
> + if (ks->authenticated != KS_AUTH_FALSE)
> {
> #ifdef ENABLE_DEF_AUTH
> unsigned int s1 = ACF_DISABLED;
> @@ -967,7 +967,7 @@ tls_authentication_status(struct tls_multi *multi, const
> int latency)
> case ACF_SUCCEEDED:
> case ACF_DISABLED:
> success = true;
> - ks->auth_deferred = false;
> + ks->authenticated = KS_AUTH_TRUE;
> break;
>
> case ACF_UNDEFINED:
> @@ -978,7 +978,7 @@ tls_authentication_status(struct tls_multi *multi, const
> int latency)
> break;
>
> case ACF_FAILED:
> - ks->authenticated = false;
> + ks->authenticated = KS_AUTH_FALSE;
> break;
>
> default:
> @@ -1308,7 +1308,7 @@ verify_user_pass(struct user_pass *up, struct tls_multi
> *multi,
> else
> {
> wipe_auth_token(multi);
> - ks->authenticated = false;
> + ks->authenticated = KS_AUTH_FALSE;
> msg(M_WARN, "TLS: Username/auth-token authentication "
> "failed for username '%s'", up->username);
> return;
> @@ -1354,17 +1354,17 @@ verify_user_pass(struct user_pass *up, struct
> tls_multi *multi,
> #endif
> && tls_lock_username(multi, up->username))
> {
> - ks->authenticated = true;
> + ks->authenticated = KS_AUTH_TRUE;
> #ifdef PLUGIN_DEF_AUTH
> if (s1 == OPENVPN_PLUGIN_FUNC_DEFERRED)
> {
> - ks->auth_deferred = true;
> + ks->authenticated = KS_AUTH_DEFERRED;
> }
> #endif
> #ifdef MANAGEMENT_DEF_AUTH
> if (man_def_auth != KMDA_UNDEF)
> {
> - ks->auth_deferred = true;
> + ks->authenticated = KS_AUTH_DEFERRED;
> }
> #endif
> if ((session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME))
> @@ -1416,7 +1416,7 @@ verify_user_pass(struct user_pass *up, struct tls_multi
> *multi,
> }
> #ifdef ENABLE_DEF_AUTH
> msg(D_HANDSHAKE, "TLS: Username/Password authentication %s for
> username '%s' %s",
> - ks->auth_deferred ? "deferred" : "succeeded",
> + (ks->authenticated == KS_AUTH_DEFERRED) ? "deferred" :
> "succeeded",
> up->username,
> (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN
> SET]" : "");
> #else
> @@ -1428,6 +1428,7 @@ verify_user_pass(struct user_pass *up, struct tls_multi
> *multi,
> }
> else
> {
> + ks->authenticated = KS_AUTH_FALSE;
Previously there was no code here doing anything like this.
Is this line actually fixing a bug? Or why is being added?
Since this patch is just about merging the two members, I'd stick with
it and avoid adding other changes that may introduce their own issue, no?
I'd personally keep this line for its own patch, coming with a proper
explanation as to why that is needed.
> msg(D_TLS_ERRORS, "TLS Auth Error: Auth Username/Password
> verification failed for peer");
> }
> }
> @@ -1444,7 +1445,7 @@ verify_final_auth_checks(struct tls_multi *multi,
> struct tls_session *session)
> }
>
> /* Don't allow the CN to change once it's been locked */
> - if (ks->authenticated && multi->locked_cn)
> + if (ks->authenticated != KS_AUTH_FALSE && multi->locked_cn)
> {
> const char *cn = session->common_name;
> if (cn && strcmp(cn, multi->locked_cn))
> @@ -1460,7 +1461,7 @@ verify_final_auth_checks(struct tls_multi *multi,
> struct tls_session *session)
> }
>
> /* Don't allow the cert hashes to change once they have been locked */
> - if (ks->authenticated && multi->locked_cert_hash_set)
> + if (ks->authenticated != KS_AUTH_FALSE && multi->locked_cert_hash_set)
> {
> const struct cert_hash_set *chs = session->cert_hash_set;
> if (chs && !cert_hash_compare(chs, multi->locked_cert_hash_set))
> @@ -1474,7 +1475,7 @@ verify_final_auth_checks(struct tls_multi *multi,
> struct tls_session *session)
> }
>
> /* verify --client-config-dir based authentication */
> - if (ks->authenticated && session->opt->client_config_dir_exclusive)
> + if (ks->authenticated != KS_AUTH_FALSE &&
> session->opt->client_config_dir_exclusive)
> {
> struct gc_arena gc = gc_new();
>
> @@ -1483,7 +1484,7 @@ verify_final_auth_checks(struct tls_multi *multi,
> struct tls_session *session)
> cn, &gc);
> if (!cn || !strcmp(cn, CCD_DEFAULT) || !platform_test_file(path))
> {
> - ks->authenticated = false;
> + ks->authenticated = KS_AUTH_FALSE;
> wipe_auth_token(multi);
> msg(D_TLS_ERRORS, "TLS Auth Error: --client-config-dir
> authentication failed for common name '%s' file='%s'",
> session->common_name,
>
The rest looks good, but can't ACK as it is.
Regards,
--
Antonio Quartulli
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