| Message ID | 20200708071750.13213-1-arne@rfc2549.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [Openvpn-devel,v2] Make key_state->authenticated more state machine like | expand |
Hi, On 08/07/2020 09:17, Arne Schwabe wrote: > This order the states from unauthenticated to authenticated and also > changes the comparison for KS_AUTH_FALSE from != to > > > It also add comments and documents part using the state machine > better. > > Remove a now obsolete comment and two obsolete ifdefs. While > keeping the ifdef in ssl_verify would save a few bytes of code, > this is too minor to justify keeping the ifdef > > Signed-off-by: Arne Schwabe <arne@rfc2549.org> > --- > src/openvpn/multi.c | 12 +++++++++--- > src/openvpn/ssl.c | 7 ++++--- > src/openvpn/ssl_common.h | 14 ++++++++------ > src/openvpn/ssl_verify.c | 18 +++++++----------- > 4 files changed, 28 insertions(+), 23 deletions(-) > > diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c > index f1ced9b7..f1332c8d 100644 > --- a/src/openvpn/multi.c > +++ b/src/openvpn/multi.c > @@ -2352,12 +2352,12 @@ multi_process_post(struct multi_context *m, struct multi_instance *mi, const uns > if (!IS_SIG(&mi->context) && ((flags & MPP_PRE_SELECT) || ((flags & MPP_CONDITIONAL_PRE_SELECT) && !ANY_OUT(&mi->context)))) > { > #if defined(ENABLE_ASYNC_PUSH) && defined(ENABLE_DEF_AUTH) > - bool was_authenticated = false; > + bool was_unauthenticated = true; > struct key_state *ks = NULL; > if (mi->context.c2.tls_multi) > { > ks = &mi->context.c2.tls_multi->session[TM_ACTIVE].key[KS_PRIMARY]; > - was_authenticated = ks->authenticated; > + was_unauthenticated = (ks->authenticated == KS_AUTH_FALSE); > } > #endif > > @@ -2366,7 +2366,13 @@ multi_process_post(struct multi_context *m, struct multi_instance *mi, const uns > pre_select(&mi->context); > > #if defined(ENABLE_ASYNC_PUSH) && defined(ENABLE_DEF_AUTH) > - if (ks && ks->auth_control_file && ks->auth_deferred && !was_authenticated) > + /* > + * if we see the state transition from unauthenticated to deferred > + * and a auth_control_file, we assume it got just added and add > + * inotify watch to that file > + */ > + if (ks && ks->auth_control_file && was_unauthenticated > + && (ks->authenticated == KS_AUTH_DEFERRED)) > { > /* watch acf file */ > long watch_descriptor = inotify_add_watch(m->top.c2.inotify_fd, ks->auth_control_file, IN_CLOSE_WRITE | IN_ONESHOT); > diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c > index 71565dd3..94fb0c5b 100644 > --- a/src/openvpn/ssl.c > +++ b/src/openvpn/ssl.c > @@ -2465,7 +2465,7 @@ key_method_2_write(struct buffer *buf, struct tls_session *session) > */ > if (session->opt->server && !(session->opt->mode == MODE_SERVER && ks->key_id <= 0)) > { > - if (ks->authenticated != KS_AUTH_FALSE) > + if (ks->authenticated > KS_AUTH_FALSE) > { > if (!tls_session_generate_data_channel_keys(session)) > { > @@ -2646,7 +2646,7 @@ key_method_2_read(struct buffer *buf, struct tls_multi *multi, struct tls_sessio > secure_memzero(up, sizeof(*up)); > > /* Perform final authentication checks */ > - if (ks->authenticated != KS_AUTH_FALSE) > + if (ks->authenticated > KS_AUTH_FALSE) > { > verify_final_auth_checks(multi, session); > } > @@ -2671,7 +2671,7 @@ 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 != KS_AUTH_FALSE) > + if ((ks->authenticated > KS_AUTH_FALSE) > && plugin_defined(session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL)) > { > key_state_export_keying_material(&ks->ks_ssl, session); > @@ -2702,6 +2702,7 @@ key_method_2_read(struct buffer *buf, struct tls_multi *multi, struct tls_sessio > return true; > > error: > + ks->authenticated = KS_AUTH_FALSE; > secure_memzero(ks->key_src, sizeof(*ks->key_src)); > if (up) > { > diff --git a/src/openvpn/ssl_common.h b/src/openvpn/ssl_common.h > index fdf589b5..91e55c7a 100644 > --- a/src/openvpn/ssl_common.h > +++ b/src/openvpn/ssl_common.h > @@ -128,9 +128,14 @@ struct key_source2 { > }; > I suggest adding a comment on top of this enum declaration. I'd suggest something like this: /* * The following enum represents the status of the key-state object * during its life-cycle. Based on the step taken by the server code, * the status will move forward by one (or more) values. This allows * us to make more flexible status checks by using the ">" or "<" * operator */ > enum ks_auth_state { > - KS_AUTH_FALSE, > - KS_AUTH_TRUE, > - KS_AUTH_DEFERRED > + KS_AUTH_FALSE, /**< Key state is not authenticated */ > + KS_AUTH_DEFERRED, /**< Key state authentication is being deferred, > + * by async auth */ > + KS_AUTH_TRUE /**< Key state is authenticated. TLS and user/pass > + * succeeded. This include AUTH_PENDING/OOB > + * authentication as those hold the > + * connection artifically in KS_AUTH_DEFERRED > + */ > }; > > /** > @@ -194,8 +199,6 @@ struct key_state > enum ks_auth_state authenticated; > time_t auth_deferred_expire; > > -#ifdef ENABLE_DEF_AUTH > - /* If auth_deferred is true, authentication is being deferred */ > #ifdef MANAGEMENT_DEF_AUTH > unsigned int mda_key_id; > unsigned int mda_status; > @@ -205,7 +208,6 @@ struct key_state > time_t acf_last_mod; > char *auth_control_file; > #endif > -#endif > }; > > /** Control channel wrapping (--tls-auth/--tls-crypt) context */ > diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c > index e28f1f3a..990fba99 100644 > --- a/src/openvpn/ssl_verify.c > +++ b/src/openvpn/ssl_verify.c > @@ -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 != KS_AUTH_FALSE) > + if (ks->authenticated > KS_AUTH_FALSE) > { > #ifdef ENABLE_DEF_AUTH > unsigned int s1 = ACF_DISABLED; > @@ -1249,6 +1249,9 @@ verify_user_pass_management(struct tls_session *session, > > /* > * Main username/password verification entry point > + * > + * Will set session->ks[KS_PRIMARY].authenticated according to > + * result of the username/password verifcation > */ > void > verify_user_pass(struct user_pass *up, struct tls_multi *multi, > @@ -1414,17 +1417,10 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi, > */ > send_push_reply_auth_token(multi); > } > -#ifdef ENABLE_DEF_AUTH > msg(D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s", > (ks->authenticated == KS_AUTH_DEFERRED) ? "deferred" : "succeeded", > up->username, > (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : ""); > -#else > - msg(D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s", > - "succeeded", > - up->username, > - (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : ""); > -#endif > } > else > { > @@ -1445,7 +1441,7 @@ 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 != KS_AUTH_FALSE && 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)) > @@ -1461,7 +1457,7 @@ 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 != KS_AUTH_FALSE && 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)) > @@ -1475,7 +1471,7 @@ verify_final_auth_checks(struct tls_multi *multi, struct tls_session *session) > } > > /* verify --client-config-dir based authentication */ > - if (ks->authenticated != KS_AUTH_FALSE && session->opt->client_config_dir_exclusive) > + if (ks->authenticated > KS_AUTH_FALSE && session->opt->client_config_dir_exclusive) > { > struct gc_arena gc = gc_new(); > > The rest looks good! I don't have a super strong opinion about that comment I proposed, but I think it can help to better understand how the state enum is used and how to modify it in the future. I'd prefer to have it, but in any case: Acked-by: Antonio Quartulli <a@unstable.cc>
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c index f1ced9b7..f1332c8d 100644 --- a/src/openvpn/multi.c +++ b/src/openvpn/multi.c @@ -2352,12 +2352,12 @@ multi_process_post(struct multi_context *m, struct multi_instance *mi, const uns if (!IS_SIG(&mi->context) && ((flags & MPP_PRE_SELECT) || ((flags & MPP_CONDITIONAL_PRE_SELECT) && !ANY_OUT(&mi->context)))) { #if defined(ENABLE_ASYNC_PUSH) && defined(ENABLE_DEF_AUTH) - bool was_authenticated = false; + bool was_unauthenticated = true; struct key_state *ks = NULL; if (mi->context.c2.tls_multi) { ks = &mi->context.c2.tls_multi->session[TM_ACTIVE].key[KS_PRIMARY]; - was_authenticated = ks->authenticated; + was_unauthenticated = (ks->authenticated == KS_AUTH_FALSE); } #endif @@ -2366,7 +2366,13 @@ multi_process_post(struct multi_context *m, struct multi_instance *mi, const uns pre_select(&mi->context); #if defined(ENABLE_ASYNC_PUSH) && defined(ENABLE_DEF_AUTH) - if (ks && ks->auth_control_file && ks->auth_deferred && !was_authenticated) + /* + * if we see the state transition from unauthenticated to deferred + * and a auth_control_file, we assume it got just added and add + * inotify watch to that file + */ + if (ks && ks->auth_control_file && was_unauthenticated + && (ks->authenticated == KS_AUTH_DEFERRED)) { /* watch acf file */ long watch_descriptor = inotify_add_watch(m->top.c2.inotify_fd, ks->auth_control_file, IN_CLOSE_WRITE | IN_ONESHOT); diff --git a/src/openvpn/ssl.c b/src/openvpn/ssl.c index 71565dd3..94fb0c5b 100644 --- a/src/openvpn/ssl.c +++ b/src/openvpn/ssl.c @@ -2465,7 +2465,7 @@ key_method_2_write(struct buffer *buf, struct tls_session *session) */ if (session->opt->server && !(session->opt->mode == MODE_SERVER && ks->key_id <= 0)) { - if (ks->authenticated != KS_AUTH_FALSE) + if (ks->authenticated > KS_AUTH_FALSE) { if (!tls_session_generate_data_channel_keys(session)) { @@ -2646,7 +2646,7 @@ key_method_2_read(struct buffer *buf, struct tls_multi *multi, struct tls_sessio secure_memzero(up, sizeof(*up)); /* Perform final authentication checks */ - if (ks->authenticated != KS_AUTH_FALSE) + if (ks->authenticated > KS_AUTH_FALSE) { verify_final_auth_checks(multi, session); } @@ -2671,7 +2671,7 @@ 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 != KS_AUTH_FALSE) + if ((ks->authenticated > KS_AUTH_FALSE) && plugin_defined(session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL)) { key_state_export_keying_material(&ks->ks_ssl, session); @@ -2702,6 +2702,7 @@ key_method_2_read(struct buffer *buf, struct tls_multi *multi, struct tls_sessio return true; error: + ks->authenticated = KS_AUTH_FALSE; secure_memzero(ks->key_src, sizeof(*ks->key_src)); if (up) { diff --git a/src/openvpn/ssl_common.h b/src/openvpn/ssl_common.h index fdf589b5..91e55c7a 100644 --- a/src/openvpn/ssl_common.h +++ b/src/openvpn/ssl_common.h @@ -128,9 +128,14 @@ struct key_source2 { }; enum ks_auth_state { - KS_AUTH_FALSE, - KS_AUTH_TRUE, - KS_AUTH_DEFERRED + KS_AUTH_FALSE, /**< Key state is not authenticated */ + KS_AUTH_DEFERRED, /**< Key state authentication is being deferred, + * by async auth */ + KS_AUTH_TRUE /**< Key state is authenticated. TLS and user/pass + * succeeded. This include AUTH_PENDING/OOB + * authentication as those hold the + * connection artifically in KS_AUTH_DEFERRED + */ }; /** @@ -194,8 +199,6 @@ struct key_state enum ks_auth_state authenticated; time_t auth_deferred_expire; -#ifdef ENABLE_DEF_AUTH - /* If auth_deferred is true, authentication is being deferred */ #ifdef MANAGEMENT_DEF_AUTH unsigned int mda_key_id; unsigned int mda_status; @@ -205,7 +208,6 @@ struct key_state time_t acf_last_mod; char *auth_control_file; #endif -#endif }; /** Control channel wrapping (--tls-auth/--tls-crypt) context */ diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c index e28f1f3a..990fba99 100644 --- a/src/openvpn/ssl_verify.c +++ b/src/openvpn/ssl_verify.c @@ -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 != KS_AUTH_FALSE) + if (ks->authenticated > KS_AUTH_FALSE) { #ifdef ENABLE_DEF_AUTH unsigned int s1 = ACF_DISABLED; @@ -1249,6 +1249,9 @@ verify_user_pass_management(struct tls_session *session, /* * Main username/password verification entry point + * + * Will set session->ks[KS_PRIMARY].authenticated according to + * result of the username/password verifcation */ void verify_user_pass(struct user_pass *up, struct tls_multi *multi, @@ -1414,17 +1417,10 @@ verify_user_pass(struct user_pass *up, struct tls_multi *multi, */ send_push_reply_auth_token(multi); } -#ifdef ENABLE_DEF_AUTH msg(D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s", (ks->authenticated == KS_AUTH_DEFERRED) ? "deferred" : "succeeded", up->username, (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : ""); -#else - msg(D_HANDSHAKE, "TLS: Username/Password authentication %s for username '%s' %s", - "succeeded", - up->username, - (session->opt->ssl_flags & SSLF_USERNAME_AS_COMMON_NAME) ? "[CN SET]" : ""); -#endif } else { @@ -1445,7 +1441,7 @@ 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 != KS_AUTH_FALSE && 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)) @@ -1461,7 +1457,7 @@ 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 != KS_AUTH_FALSE && 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)) @@ -1475,7 +1471,7 @@ verify_final_auth_checks(struct tls_multi *multi, struct tls_session *session) } /* verify --client-config-dir based authentication */ - if (ks->authenticated != KS_AUTH_FALSE && session->opt->client_config_dir_exclusive) + if (ks->authenticated > KS_AUTH_FALSE && session->opt->client_config_dir_exclusive) { struct gc_arena gc = gc_new();
This order the states from unauthenticated to authenticated and also changes the comparison for KS_AUTH_FALSE from != to > It also add comments and documents part using the state machine better. Remove a now obsolete comment and two obsolete ifdefs. While keeping the ifdef in ssl_verify would save a few bytes of code, this is too minor to justify keeping the ifdef Signed-off-by: Arne Schwabe <arne@rfc2549.org> --- src/openvpn/multi.c | 12 +++++++++--- src/openvpn/ssl.c | 7 ++++--- src/openvpn/ssl_common.h | 14 ++++++++------ src/openvpn/ssl_verify.c | 18 +++++++----------- 4 files changed, 28 insertions(+), 23 deletions(-)