| Message ID | 20210503125335.3918335-1-arne@rfc2549.org |
|---|---|
| State | Changes Requested |
| Delegated to: | Antonio Quartulli |
| Headers | show |
| Series | None | expand |
Hi, Something in this patch is not working as expected. I tested with master + this patch. When a client connects and inputs the wrong password, the server goes into a loop: 2021-05-06 00:50:46 10.10.10.2:1194 Delayed exit in 5 seconds 2021-05-06 00:50:46 10.10.10.2:1194 SENT CONTROL [client]: 'AUTH_FAILED' (status=1) 2021-05-06 00:50:46 10.10.10.2:1194 Delayed exit in 5 seconds 2021-05-06 00:50:46 10.10.10.2:1194 SENT CONTROL [client]: 'AUTH_FAILED' (status=1) 2021-05-06 00:50:46 10.10.10.2:1194 Delayed exit in 5 seconds 2021-05-06 00:50:46 10.10.10.2:1194 SENT CONTROL [client]: 'AUTH_FAILED' (status=1) and goes on... Without this patch I don't see this problem. After adding some debug messages I saw that without this patch the return value of tls_authentication_status() in tls_multi_process() is *always* UNDEFINED, also after the auth failure. This said I stopped digging there because the bed is calling... Arne, maybe you can spot what's wrong? Regards, On 03/05/2021 14:53, Arne Schwabe wrote: > tls_authentication_status does caching to avoid file I/O more than > every TLS_MULTI_AUTH_STATUS_INTERVAL (10s) per connection. But > counter-intuitively it does not return the cached result but rather > TLS_AUTHENTICATION_UNDEFINED if the cache is not refreshed by the call. > > This is workarounded by forcing a refresh in some areas of the code > (latency = 0). > > This patch changes the behaviour by always returning the last known > status and only updating the file status when the i/o timeout for the > caches is reached. > > The patch also changes the DEFINE enum into a real enum. > > Patch v2: only update tas_cache_last_udpate when actually updating the cache. > > Signed-off-by: Arne Schwabe <arne@rfc2549.org> > --- > src/openvpn/multi.c | 2 +- > src/openvpn/push.c | 3 ++- > src/openvpn/ssl_common.h | 16 +++++++++--- > src/openvpn/ssl_verify.c | 53 ++++++++++++++++++++++------------------ > src/openvpn/ssl_verify.h | 3 +-- > 5 files changed, 46 insertions(+), 31 deletions(-) > > diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c > index 666456da9..ab2270a58 100644 > --- a/src/openvpn/multi.c > +++ b/src/openvpn/multi.c > @@ -2596,7 +2596,7 @@ static const multi_client_connect_handler client_connect_handlers[] = { > static void > multi_connection_established(struct multi_context *m, struct multi_instance *mi) > { > - if (tls_authentication_status(mi->context.c2.tls_multi, 0) > + if (tls_authentication_status(mi->context.c2.tls_multi, TLS_MULTI_AUTH_STATUS_INTERVAL) > != TLS_AUTHENTICATION_SUCCEEDED) > { > return; > diff --git a/src/openvpn/push.c b/src/openvpn/push.c > index fcafc5003..428efb68e 100644 > --- a/src/openvpn/push.c > +++ b/src/openvpn/push.c > @@ -855,7 +855,8 @@ process_incoming_push_request(struct context *c) > { > int ret = PUSH_MSG_ERROR; > > - if (tls_authentication_status(c->c2.tls_multi, 0) == TLS_AUTHENTICATION_FAILED > + > + if (tls_authentication_status(c->c2.tls_multi, TLS_MULTI_AUTH_STATUS_INTERVAL) == TLS_AUTHENTICATION_FAILED > || c->c2.tls_multi->multi_state == CAS_FAILED) > { > const char *client_reason = tls_client_reason(c->c2.tls_multi); > diff --git a/src/openvpn/ssl_common.h b/src/openvpn/ssl_common.h > index 9c923f2a6..52488a163 100644 > --- a/src/openvpn/ssl_common.h > +++ b/src/openvpn/ssl_common.h > @@ -152,6 +152,15 @@ struct auth_deferred_status > unsigned int auth_control_status; > }; > > +/* key_state_test_auth_control_file return values, these specify the > + * current status of a deferred authentication */ > +enum auth_deferred_result { > + ACF_PENDING, /**< deferred auth still pending */ > + ACF_SUCCEEDED, /**< deferred auth has suceeded */ > + ACF_DISABLED, /**< deferred auth is not used */ > + ACF_FAILED /**< deferred auth has failed */ > +}; > + > /** > * Security parameter state of one TLS and data channel %key session. > * @ingroup control_processor > @@ -219,7 +228,7 @@ struct key_state > > #ifdef ENABLE_MANAGEMENT > unsigned int mda_key_id; > - unsigned int mda_status; > + enum auth_deferred_result mda_status; > #endif > time_t acf_last_mod; > > @@ -561,8 +570,9 @@ struct tls_multi > char *locked_username; > struct cert_hash_set *locked_cert_hash_set; > > - /* Time of last call to tls_authentication_status */ > - time_t tas_last; > + /* Time of last when we updated the cached state of > + * tls_authentication_status deferred files */ > + time_t tas_cache_last_update; > > /* > * An error message to send to client on AUTH_FAILED > diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c > index 34ee19caf..b1b01f777 100644 > --- a/src/openvpn/ssl_verify.c > +++ b/src/openvpn/ssl_verify.c > @@ -845,13 +845,6 @@ cleanup: > * user/password authentication. > *************************************************************************** */ > > -/* key_state_test_auth_control_file return values, > - * NOTE: acf_merge indexing depends on these values */ > -#define ACF_UNDEFINED 0 > -#define ACF_SUCCEEDED 1 > -#define ACF_DISABLED 2 > -#define ACF_FAILED 3 > - > void > auth_set_client_reason(struct tls_multi *multi, const char *client_reason) > { > @@ -866,7 +859,7 @@ auth_set_client_reason(struct tls_multi *multi, const char *client_reason) > > #ifdef ENABLE_MANAGEMENT > > -static inline unsigned int > +static inline enum auth_deferred_result > man_def_auth_test(const struct key_state *ks) > { > if (management_enable_def_auth(management)) > @@ -1041,13 +1034,23 @@ key_state_gen_auth_control_files(struct auth_deferred_status *ads, > return (acf && apf); > } > > -static unsigned int > -key_state_test_auth_control_file(struct auth_deferred_status *ads) > +/** > + * Checks the control status from a file. The function will try to read > + * and update the cached status if the status is still pending and the paramter > + * cached is false. The function returns the > + * > + * > + * @param ads deferred status control structure > + * @param cached Return only cached status > + * @return > + */ > +static enum auth_deferred_result > +key_state_test_auth_control_file(struct auth_deferred_status *ads, bool cached) > { > if (ads->auth_control_file) > { > unsigned int ret = ads->auth_control_status; > - if (ret == ACF_UNDEFINED) > + if (ret == ACF_PENDING && !cached) > { > FILE *fp = fopen(ads->auth_control_file, "r"); > if (fp) > @@ -1084,11 +1087,7 @@ tls_authentication_status(struct tls_multi *multi, const int latency) > /* at least one key already failed authentication */ > bool failed_auth = false; > > - if (latency && multi->tas_last + latency >= now) > - { > - return TLS_AUTHENTICATION_UNDEFINED; > - } > - multi->tas_last = now; > + bool cached = multi->tas_cache_last_update + latency >= now; > > for (int i = 0; i < KEY_SCAN_SIZE; ++i) > { > @@ -1102,11 +1101,11 @@ tls_authentication_status(struct tls_multi *multi, const int latency) > } > else > { > - unsigned int auth_plugin = ACF_DISABLED; > - unsigned int auth_script = ACF_DISABLED; > - unsigned int auth_man = ACF_DISABLED; > - auth_plugin = key_state_test_auth_control_file(&ks->plugin_auth); > - auth_script = key_state_test_auth_control_file(&ks->script_auth); > + enum auth_deferred_result auth_plugin = ACF_DISABLED; > + enum auth_deferred_result auth_script = ACF_DISABLED; > + enum auth_deferred_result auth_man = ACF_DISABLED; > + auth_plugin = key_state_test_auth_control_file(&ks->plugin_auth, cached); > + auth_script = key_state_test_auth_control_file(&ks->script_auth, cached); > #ifdef ENABLE_MANAGEMENT > auth_man = man_def_auth_test(ks); > #endif > @@ -1118,9 +1117,9 @@ tls_authentication_status(struct tls_multi *multi, const int latency) > ks->authenticated = KS_AUTH_FALSE; > failed_auth = true; > } > - else if (auth_plugin == ACF_UNDEFINED > - || auth_script == ACF_UNDEFINED > - || auth_man == ACF_UNDEFINED) > + else if (auth_plugin == ACF_PENDING > + || auth_script == ACF_PENDING > + || auth_man == ACF_PENDING) > { > if (now < ks->auth_deferred_expire) > { > @@ -1140,6 +1139,12 @@ tls_authentication_status(struct tls_multi *multi, const int latency) > } > } > > + /* we did not rely on a cached result, remember the cache update time */ > + if (!cached) > + { > + multi->tas_cache_last_update = now; > + } > + > #if 0 > dmsg(D_TLS_ERRORS, "TAS: a=%d s=%d d=%d f=%d", active, success, deferred, failed_auth); > #endif > diff --git a/src/openvpn/ssl_verify.h b/src/openvpn/ssl_verify.h > index 8358fb986..06b88b568 100644 > --- a/src/openvpn/ssl_verify.h > +++ b/src/openvpn/ssl_verify.h > @@ -69,8 +69,7 @@ enum tls_auth_status > { > TLS_AUTHENTICATION_SUCCEEDED=0, > TLS_AUTHENTICATION_FAILED=1, > - TLS_AUTHENTICATION_DEFERRED=2, > - TLS_AUTHENTICATION_UNDEFINED=3 > + TLS_AUTHENTICATION_DEFERRED=2 > }; > > /** >
diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c index 666456da9..ab2270a58 100644 --- a/src/openvpn/multi.c +++ b/src/openvpn/multi.c @@ -2596,7 +2596,7 @@ static const multi_client_connect_handler client_connect_handlers[] = { static void multi_connection_established(struct multi_context *m, struct multi_instance *mi) { - if (tls_authentication_status(mi->context.c2.tls_multi, 0) + if (tls_authentication_status(mi->context.c2.tls_multi, TLS_MULTI_AUTH_STATUS_INTERVAL) != TLS_AUTHENTICATION_SUCCEEDED) { return; diff --git a/src/openvpn/push.c b/src/openvpn/push.c index fcafc5003..428efb68e 100644 --- a/src/openvpn/push.c +++ b/src/openvpn/push.c @@ -855,7 +855,8 @@ process_incoming_push_request(struct context *c) { int ret = PUSH_MSG_ERROR; - if (tls_authentication_status(c->c2.tls_multi, 0) == TLS_AUTHENTICATION_FAILED + + if (tls_authentication_status(c->c2.tls_multi, TLS_MULTI_AUTH_STATUS_INTERVAL) == TLS_AUTHENTICATION_FAILED || c->c2.tls_multi->multi_state == CAS_FAILED) { const char *client_reason = tls_client_reason(c->c2.tls_multi); diff --git a/src/openvpn/ssl_common.h b/src/openvpn/ssl_common.h index 9c923f2a6..52488a163 100644 --- a/src/openvpn/ssl_common.h +++ b/src/openvpn/ssl_common.h @@ -152,6 +152,15 @@ struct auth_deferred_status unsigned int auth_control_status; }; +/* key_state_test_auth_control_file return values, these specify the + * current status of a deferred authentication */ +enum auth_deferred_result { + ACF_PENDING, /**< deferred auth still pending */ + ACF_SUCCEEDED, /**< deferred auth has suceeded */ + ACF_DISABLED, /**< deferred auth is not used */ + ACF_FAILED /**< deferred auth has failed */ +}; + /** * Security parameter state of one TLS and data channel %key session. * @ingroup control_processor @@ -219,7 +228,7 @@ struct key_state #ifdef ENABLE_MANAGEMENT unsigned int mda_key_id; - unsigned int mda_status; + enum auth_deferred_result mda_status; #endif time_t acf_last_mod; @@ -561,8 +570,9 @@ struct tls_multi char *locked_username; struct cert_hash_set *locked_cert_hash_set; - /* Time of last call to tls_authentication_status */ - time_t tas_last; + /* Time of last when we updated the cached state of + * tls_authentication_status deferred files */ + time_t tas_cache_last_update; /* * An error message to send to client on AUTH_FAILED diff --git a/src/openvpn/ssl_verify.c b/src/openvpn/ssl_verify.c index 34ee19caf..b1b01f777 100644 --- a/src/openvpn/ssl_verify.c +++ b/src/openvpn/ssl_verify.c @@ -845,13 +845,6 @@ cleanup: * user/password authentication. *************************************************************************** */ -/* key_state_test_auth_control_file return values, - * NOTE: acf_merge indexing depends on these values */ -#define ACF_UNDEFINED 0 -#define ACF_SUCCEEDED 1 -#define ACF_DISABLED 2 -#define ACF_FAILED 3 - void auth_set_client_reason(struct tls_multi *multi, const char *client_reason) { @@ -866,7 +859,7 @@ auth_set_client_reason(struct tls_multi *multi, const char *client_reason) #ifdef ENABLE_MANAGEMENT -static inline unsigned int +static inline enum auth_deferred_result man_def_auth_test(const struct key_state *ks) { if (management_enable_def_auth(management)) @@ -1041,13 +1034,23 @@ key_state_gen_auth_control_files(struct auth_deferred_status *ads, return (acf && apf); } -static unsigned int -key_state_test_auth_control_file(struct auth_deferred_status *ads) +/** + * Checks the control status from a file. The function will try to read + * and update the cached status if the status is still pending and the paramter + * cached is false. The function returns the + * + * + * @param ads deferred status control structure + * @param cached Return only cached status + * @return + */ +static enum auth_deferred_result +key_state_test_auth_control_file(struct auth_deferred_status *ads, bool cached) { if (ads->auth_control_file) { unsigned int ret = ads->auth_control_status; - if (ret == ACF_UNDEFINED) + if (ret == ACF_PENDING && !cached) { FILE *fp = fopen(ads->auth_control_file, "r"); if (fp) @@ -1084,11 +1087,7 @@ tls_authentication_status(struct tls_multi *multi, const int latency) /* at least one key already failed authentication */ bool failed_auth = false; - if (latency && multi->tas_last + latency >= now) - { - return TLS_AUTHENTICATION_UNDEFINED; - } - multi->tas_last = now; + bool cached = multi->tas_cache_last_update + latency >= now; for (int i = 0; i < KEY_SCAN_SIZE; ++i) { @@ -1102,11 +1101,11 @@ tls_authentication_status(struct tls_multi *multi, const int latency) } else { - unsigned int auth_plugin = ACF_DISABLED; - unsigned int auth_script = ACF_DISABLED; - unsigned int auth_man = ACF_DISABLED; - auth_plugin = key_state_test_auth_control_file(&ks->plugin_auth); - auth_script = key_state_test_auth_control_file(&ks->script_auth); + enum auth_deferred_result auth_plugin = ACF_DISABLED; + enum auth_deferred_result auth_script = ACF_DISABLED; + enum auth_deferred_result auth_man = ACF_DISABLED; + auth_plugin = key_state_test_auth_control_file(&ks->plugin_auth, cached); + auth_script = key_state_test_auth_control_file(&ks->script_auth, cached); #ifdef ENABLE_MANAGEMENT auth_man = man_def_auth_test(ks); #endif @@ -1118,9 +1117,9 @@ tls_authentication_status(struct tls_multi *multi, const int latency) ks->authenticated = KS_AUTH_FALSE; failed_auth = true; } - else if (auth_plugin == ACF_UNDEFINED - || auth_script == ACF_UNDEFINED - || auth_man == ACF_UNDEFINED) + else if (auth_plugin == ACF_PENDING + || auth_script == ACF_PENDING + || auth_man == ACF_PENDING) { if (now < ks->auth_deferred_expire) { @@ -1140,6 +1139,12 @@ tls_authentication_status(struct tls_multi *multi, const int latency) } } + /* we did not rely on a cached result, remember the cache update time */ + if (!cached) + { + multi->tas_cache_last_update = now; + } + #if 0 dmsg(D_TLS_ERRORS, "TAS: a=%d s=%d d=%d f=%d", active, success, deferred, failed_auth); #endif diff --git a/src/openvpn/ssl_verify.h b/src/openvpn/ssl_verify.h index 8358fb986..06b88b568 100644 --- a/src/openvpn/ssl_verify.h +++ b/src/openvpn/ssl_verify.h @@ -69,8 +69,7 @@ enum tls_auth_status { TLS_AUTHENTICATION_SUCCEEDED=0, TLS_AUTHENTICATION_FAILED=1, - TLS_AUTHENTICATION_DEFERRED=2, - TLS_AUTHENTICATION_UNDEFINED=3 + TLS_AUTHENTICATION_DEFERRED=2 }; /**
tls_authentication_status does caching to avoid file I/O more than every TLS_MULTI_AUTH_STATUS_INTERVAL (10s) per connection. But counter-intuitively it does not return the cached result but rather TLS_AUTHENTICATION_UNDEFINED if the cache is not refreshed by the call. This is workarounded by forcing a refresh in some areas of the code (latency = 0). This patch changes the behaviour by always returning the last known status and only updating the file status when the i/o timeout for the caches is reached. The patch also changes the DEFINE enum into a real enum. Patch v2: only update tas_cache_last_udpate when actually updating the cache. Signed-off-by: Arne Schwabe <arne@rfc2549.org> --- src/openvpn/multi.c | 2 +- src/openvpn/push.c | 3 ++- src/openvpn/ssl_common.h | 16 +++++++++--- src/openvpn/ssl_verify.c | 53 ++++++++++++++++++++++------------------ src/openvpn/ssl_verify.h | 3 +-- 5 files changed, 46 insertions(+), 31 deletions(-)