diff options
-rw-r--r-- | doc/ssl/SSL_CTX_add_session.pod | 8 | ||||
-rw-r--r-- | doc/ssl/SSL_CTX_set_session_cache_mode.pod | 47 | ||||
-rw-r--r-- | ssl/ssl.h | 7 | ||||
-rw-r--r-- | ssl/ssl_lib.c | 2 | ||||
-rw-r--r-- | ssl/ssl_sess.c | 9 |
5 files changed, 54 insertions, 19 deletions
diff --git a/doc/ssl/SSL_CTX_add_session.pod b/doc/ssl/SSL_CTX_add_session.pod index af326c2f73..82676b26b2 100644 --- a/doc/ssl/SSL_CTX_add_session.pod +++ b/doc/ssl/SSL_CTX_add_session.pod @@ -37,6 +37,14 @@ removed and replaced by the new session. If the session is actually identical (the SSL_SESSION object is identical), SSL_CTX_add_session() is a no-op, and the return value is 0. +If a server SSL_CTX is configured with the SSL_SESS_CACHE_NO_INTERNAL_STORE +flag then the internal cache will not be populated automatically by new +sessions negotiated by the SSL/TLS implementation, even though the internal +cache will be searched automatically for session-resume requests (the +latter can be surpressed by SSL_SESS_CACHE_NO_INTERNAL_LOOKUP). So the +application can use SSL_CTX_add_session() directly to have full control +over the sessions that can be resumed if desired. + =head1 RETURN VALUES diff --git a/doc/ssl/SSL_CTX_set_session_cache_mode.pod b/doc/ssl/SSL_CTX_set_session_cache_mode.pod index 9aa6c6b2e3..79c9ff5793 100644 --- a/doc/ssl/SSL_CTX_set_session_cache_mode.pod +++ b/doc/ssl/SSL_CTX_set_session_cache_mode.pod @@ -26,12 +26,14 @@ SSL_CTX object is being maintained, the sessions are unique for each SSL_CTX object. In order to reuse a session, a client must send the session's id to the -server. It can only send exactly one id. The server then decides whether it -agrees in reusing the session or starts the handshake for a new session. +server. It can only send exactly one id. The server then either +agrees to reuse the session or it starts a full handshake (to create a new +session). -A server will lookup up the session in its internal session storage. If -the session is not found in internal storage or internal storage is -deactivated, the server will try the external storage if available. +A server will lookup up the session in its internal session storage. If the +session is not found in internal storage or lookups for the internal storage +have been deactivated (SSL_SESS_CACHE_NO_INTERNAL_LOOKUP), the server will try +the external storage if available. Since a client may try to reuse a session intended for use in a different context, the session id context must be set by the server (see @@ -57,9 +59,10 @@ function. This option is not activated by default. =item SSL_SESS_CACHE_SERVER Server sessions are added to the session cache. When a client proposes a -session to be reused, the session is looked up in the internal session cache. -If the session is found, the server will try to reuse the session. -This is the default. +session to be reused, the server looks for the corresponding session in (first) +the internal session cache (unless SSL_SESS_CACHE_NO_INTERNAL_LOOKUP is set), +then (second) in the external cache if available. If the session is found, the +server will try to reuse the session. This is the default. =item SSL_SESS_CACHE_BOTH @@ -77,12 +80,31 @@ explicitly by the application. =item SSL_SESS_CACHE_NO_INTERNAL_LOOKUP -By setting this flag sessions are cached in the internal storage but -they are not looked up automatically. If an external session cache -is enabled, sessions are looked up in the external cache. As automatic -lookup only applies for SSL/TLS servers, the flag has no effect on +By setting this flag, session-resume operations in an SSL/TLS server will not +automatically look up sessions in the internal cache, even if sessions are +automatically stored there. If external session caching callbacks are in use, +this flag guarantees that all lookups are directed to the external cache. +As automatic lookup only applies for SSL/TLS servers, the flag has no effect on clients. +=item SSL_SESS_CACHE_NO_INTERNAL_STORE + +Depending on the presence of SSL_SESS_CACHE_CLIENT and/or SSL_SESS_CACHE_SERVER, +sessions negotiated in an SSL/TLS handshake may be cached for possible reuse. +Normally a new session is added to the internal cache as well as any external +session caching (callback) that is configured for the SSL_CTX. This flag will +prevent sessions being stored in the internal cache (though the application can +add them manually using L<SSL_CTX_add_session(3)|SSL_CTX_add_session(3)>). Note: +in any SSL/TLS servers where external caching is configured, any successful +session lookups in the external cache (ie. for session-resume requests) would +normally be copied into the local cache before processing continues - this flag +prevents these additions to the internal cache as well. + +=item SSL_SESS_CACHE_NO_INTERNAL + +Enable both SSL_SESS_CACHE_NO_INTERNAL_LOOKUP and +SSL_SESS_CACHE_NO_INTERNAL_STORE at the same time. + =back The default mode is SSL_SESS_CACHE_SERVER. @@ -98,6 +120,7 @@ SSL_CTX_get_session_cache_mode() returns the currently set cache mode. L<ssl(3)|ssl(3)>, L<SSL_set_session(3)|SSL_set_session(3)>, L<SSL_session_reused(3)|SSL_session_reused(3)>, +L<SSL_CTX_add_session(3)|SSL_CTX_add_session(3)>, L<SSL_CTX_sess_number(3)|SSL_CTX_sess_number(3)>, L<SSL_CTX_sess_set_cache_size(3)|SSL_CTX_sess_set_cache_size(3)>, L<SSL_CTX_sess_set_get_cb(3)|SSL_CTX_sess_set_get_cb(3)>, @@ -726,10 +726,11 @@ struct ssl_ctx_st #define SSL_SESS_CACHE_SERVER 0x0002 #define SSL_SESS_CACHE_BOTH (SSL_SESS_CACHE_CLIENT|SSL_SESS_CACHE_SERVER) #define SSL_SESS_CACHE_NO_AUTO_CLEAR 0x0080 -/* This one, when set, makes the server session-id lookup not look - * in the cache. If there is an application get_session callback - * defined, this will still get called. */ +/* enough comments already ... see SSL_CTX_set_session_cache_mode(3) */ #define SSL_SESS_CACHE_NO_INTERNAL_LOOKUP 0x0100 +#define SSL_SESS_CACHE_NO_INTERNAL_STORE 0x0200 +#define SSL_SESS_CACHE_NO_INTERNAL \ + (SSL_SESS_CACHE_NO_INTERNAL_LOOKUP|SSL_SESS_CACHE_NO_INTERNAL_STORE) struct lhash_st *SSL_CTX_sessions(SSL_CTX *ctx); #define SSL_CTX_sess_number(ctx) \ diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c index 1ddd3380ac..851155e04e 100644 --- a/ssl/ssl_lib.c +++ b/ssl/ssl_lib.c @@ -1803,7 +1803,7 @@ void ssl_update_cache(SSL *s,int mode) i=s->ctx->session_cache_mode; if ((i & mode) && (!s->hit) - && ((i & SSL_SESS_CACHE_NO_INTERNAL_LOOKUP) + && ((i & SSL_SESS_CACHE_NO_INTERNAL_STORE) || SSL_CTX_add_session(s->ctx,s->session)) && (s->ctx->new_session_cb != NULL)) { diff --git a/ssl/ssl_sess.c b/ssl/ssl_sess.c index ca1a7427be..2a4a90897e 100644 --- a/ssl/ssl_sess.c +++ b/ssl/ssl_sess.c @@ -309,9 +309,12 @@ int ssl_get_prev_session(SSL *s, unsigned char *session_id, int len) if (copy) CRYPTO_add(&ret->references,1,CRYPTO_LOCK_SSL_SESSION); - /* The following should not return 1, otherwise, - * things are very strange */ - SSL_CTX_add_session(s->ctx,ret); + /* Add the externally cached session to the internal + * cache as well if and only if we are supposed to. */ + if(!(s->ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE)) + /* The following should not return 1, otherwise, + * things are very strange */ + SSL_CTX_add_session(s->ctx,ret); } if (ret == NULL) goto err; |