/*
- * Copyright (C) 1996-2016 The Squid Software Foundation and contributors
+ * Copyright (C) 1996-2020 The Squid Software Foundation and contributors
*
* Squid software is distributed under GPLv2+ license and includes
* contributions from numerous individuals and organizations.
* Please see the COPYING and CONTRIBUTORS files for details.
*/
+/* DEBUG: section 83 TLS session management */
+
#include "squid.h"
#include "anyp/PortCfg.h"
#include "base/RunnersRegistry.h"
+#include "CachePeer.h"
+#include "Debug.h"
+#include "fd.h"
+#include "fde.h"
#include "ipc/MemMap.h"
#include "security/Session.h"
#include "SquidConfig.h"
+#include "ssl/bio.h"
#define SSL_SESSION_ID_SIZE 32
#define SSL_SESSION_MAX_SIZE 10*1024
+#if USE_OPENSSL
+static Ipc::MemMap *SessionCache = nullptr;
+static const char *SessionCacheName = "tls_session_cache";
+#endif
+
+#if USE_OPENSSL || USE_GNUTLS
+static int
+tls_read_method(int fd, char *buf, int len)
+{
+ auto session = fd_table[fd].ssl.get();
+ debugs(83, 3, "started for session=" << (void*)session);
+
+#if DONT_DO_THIS && USE_OPENSSL
+ if (!SSL_is_init_finished(session)) {
+ errno = ENOTCONN;
+ return -1;
+ }
+#endif
+
+#if USE_OPENSSL
+ int i = SSL_read(session, buf, len);
+#elif USE_GNUTLS
+ int i = gnutls_record_recv(session, buf, len);
+#endif
+
+ if (i > 0) {
+ debugs(83, 8, "TLS FD " << fd << " session=" << (void*)session << " " << i << " bytes");
+ (void)VALGRIND_MAKE_MEM_DEFINED(buf, i);
+ }
+
+#if USE_OPENSSL
+ if (i > 0 && SSL_pending(session) > 0) {
+#elif USE_GNUTLS
+ if (i > 0 && gnutls_record_check_pending(session) > 0) {
+#endif
+ debugs(83, 2, "TLS FD " << fd << " is pending");
+ fd_table[fd].flags.read_pending = true;
+ } else
+ fd_table[fd].flags.read_pending = false;
+
+ return i;
+}
+
+static int
+tls_write_method(int fd, const char *buf, int len)
+{
+ auto session = fd_table[fd].ssl.get();
+ debugs(83, 3, "started for session=" << (void*)session);
+
+#if USE_OPENSSL
+ if (!SSL_is_init_finished(session)) {
+ errno = ENOTCONN;
+ return -1;
+ }
+#endif
+
+#if USE_OPENSSL
+ int i = SSL_write(session, buf, len);
+#elif USE_GNUTLS
+ int i = gnutls_record_send(session, buf, len);
+#endif
+
+ if (i > 0) {
+ debugs(83, 8, "TLS FD " << fd << " session=" << (void*)session << " " << i << " bytes");
+ }
+ return i;
+}
+#endif
+
+#if USE_OPENSSL
+Security::SessionPointer
+Security::NewSessionObject(const Security::ContextPointer &ctx)
+{
+ Security::SessionPointer session(SSL_new(ctx.get()), [](SSL *p) {
+ debugs(83, 5, "SSL_free session=" << (void*)p);
+ SSL_free(p);
+ });
+ debugs(83, 5, "SSL_new session=" << (void*)session.get());
+ return session;
+}
+#endif
+
+static bool
+CreateSession(const Security::ContextPointer &ctx, const Comm::ConnectionPointer &conn, Security::PeerOptions &opts, Security::Io::Type type, const char *squidCtx)
+{
+ if (!Comm::IsConnOpen(conn)) {
+ debugs(83, DBG_IMPORTANT, "Gone connection");
+ return false;
+ }
+
+#if USE_OPENSSL || USE_GNUTLS
+
+ const char *errAction = "with no TLS/SSL library";
+ int errCode = 0;
+#if USE_OPENSSL
+ Security::SessionPointer session(Security::NewSessionObject(ctx));
+ if (!session) {
+ errCode = ERR_get_error();
+ errAction = "failed to allocate handle";
+ debugs(83, DBG_IMPORTANT, "TLS error: " << errAction << ": " << Security::ErrorString(errCode));
+ }
+#elif USE_GNUTLS
+ gnutls_session_t tmp;
+ errCode = gnutls_init(&tmp, static_cast<unsigned int>(type) | GNUTLS_NONBLOCK);
+ Security::SessionPointer session(tmp, [](gnutls_session_t p) {
+ debugs(83, 5, "gnutls_deinit session=" << (void*)p);
+ gnutls_deinit(p);
+ });
+ debugs(83, 5, "gnutls_init " << (type == Security::Io::BIO_TO_SERVER ? "client" : "server" )<< " session=" << (void*)session.get());
+ if (errCode != GNUTLS_E_SUCCESS) {
+ session.reset();
+ errAction = "failed to initialize session";
+ debugs(83, DBG_IMPORTANT, "TLS error: " << errAction << ": " << Security::ErrorString(errCode));
+ }
+#endif
+
+ if (session) {
+ const int fd = conn->fd;
+
+#if USE_OPENSSL
+ // without BIO, we would call SSL_set_fd(ssl.get(), fd) instead
+ if (BIO *bio = Ssl::Bio::Create(fd, type)) {
+ Ssl::Bio::Link(session.get(), bio); // cannot fail
+#elif USE_GNUTLS
+ errCode = gnutls_credentials_set(session.get(), GNUTLS_CRD_CERTIFICATE, ctx.get());
+ if (errCode == GNUTLS_E_SUCCESS) {
+
+ opts.updateSessionOptions(session);
+
+ // NP: GnuTLS does not yet support the BIO operations
+ // this does the equivalent of SSL_set_fd() for now.
+ gnutls_transport_set_int(session.get(), fd);
+ gnutls_handshake_set_timeout(session.get(), GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
+#endif
+
+ debugs(83, 5, "link FD " << fd << " to TLS session=" << (void*)session.get());
+
+ fd_table[fd].ssl = session;
+ fd_table[fd].useBufferedIo(&tls_read_method, &tls_write_method);
+ fd_note(fd, squidCtx);
+ return true;
+ }
+
+#if USE_OPENSSL
+ errCode = ERR_get_error();
+ errAction = "failed to initialize I/O";
+#elif USE_GNUTLS
+ errAction = "failed to assign credentials";
+#endif
+ }
+
+ debugs(83, DBG_IMPORTANT, "ERROR: " << squidCtx << ' ' << errAction <<
+ ": " << (errCode != 0 ? Security::ErrorString(errCode) : ""));
+#endif
+ return false;
+}
+
+bool
+Security::CreateClientSession(const Security::ContextPointer &ctx, const Comm::ConnectionPointer &c, const char *squidCtx)
+{
+ if (!c || !c->getPeer())
+ return CreateSession(ctx, c, Security::ProxyOutgoingConfig, Security::Io::BIO_TO_SERVER, squidCtx);
+
+ auto *peer = c->getPeer();
+ return CreateSession(ctx, c, peer->secure, Security::Io::BIO_TO_SERVER, squidCtx);
+}
+
+bool
+Security::CreateServerSession(const Security::ContextPointer &ctx, const Comm::ConnectionPointer &c, Security::PeerOptions &o, const char *squidCtx)
+{
+ return CreateSession(ctx, c, o, Security::Io::BIO_TO_CLIENT, squidCtx);
+}
+
+void
+Security::SessionSendGoodbye(const Security::SessionPointer &s)
+{
+ debugs(83, 5, "session=" << (void*)s.get());
+ if (s) {
+#if USE_OPENSSL
+ SSL_shutdown(s.get());
+#elif USE_GNUTLS
+ gnutls_bye(s.get(), GNUTLS_SHUT_RDWR);
+#endif
+ }
+}
+
bool
Security::SessionIsResumed(const Security::SessionPointer &s)
{
- return
+ bool result = false;
#if USE_OPENSSL
- SSL_session_reused(s.get()) == 1;
+ result = SSL_session_reused(s.get()) == 1;
#elif USE_GNUTLS
- gnutls_session_is_resumed(s.get()) != 0;
-#else
- false;
+ result = gnutls_session_is_resumed(s.get()) != 0;
#endif
+ debugs(83, 7, "session=" << (void*)s.get() << ", query? answer: " << (result ? 'T' : 'F') );
+ return result;
}
void
-Security::GetSessionResumeData(const Security::SessionPointer &s, Security::SessionStatePointer &data)
+Security::MaybeGetSessionResumeData(const Security::SessionPointer &s, Security::SessionStatePointer &data)
{
if (!SessionIsResumed(s)) {
#if USE_OPENSSL
+ // nil is valid for SSL_get1_session(), it cannot fail.
data.reset(SSL_get1_session(s.get()));
#elif USE_GNUTLS
gnutls_datum_t *tmp = nullptr;
- (void)gnutls_session_get_data2(s.get(), tmp);
+ const auto x = gnutls_session_get_data2(s.get(), tmp);
+ if (x != GNUTLS_E_SUCCESS) {
+ debugs(83, 3, "session=" << (void*)s.get() << " error: " << Security::ErrorString(x));
+ }
data.reset(tmp);
#endif
+ debugs(83, 5, "session=" << (void*)s.get() << " data=" << (void*)data.get());
+ } else {
+ debugs(83, 5, "session=" << (void*)s.get() << " data=" << (void*)data.get() << ", do nothing.");
}
}
void
-Security::SetSessionResumeData(const Security::SessionPtr &s, const Security::SessionStatePointer &data)
+Security::SetSessionResumeData(const Security::SessionPointer &s, const Security::SessionStatePointer &data)
{
- if (s) {
+ if (data) {
#if USE_OPENSSL
- (void)SSL_set_session(s, data.get());
+ if (!SSL_set_session(s.get(), data.get())) {
+ const auto ssl_error = ERR_get_error();
+ debugs(83, 3, "session=" << (void*)s.get() << " data=" << (void*)data.get() <<
+ " resume error: " << Security::ErrorString(ssl_error));
+ }
#elif USE_GNUTLS
- (void)gnutls_session_set_data(s, data->data, data->size);
+ const auto x = gnutls_session_set_data(s.get(), data->data, data->size);
+ if (x != GNUTLS_E_SUCCESS) {
+ debugs(83, 3, "session=" << (void*)s.get() << " data=" << (void*)data.get() <<
+ " resume error: " << Security::ErrorString(x));
+ }
+#else
+ // critical because, how did it get here?
+ debugs(83, DBG_CRITICAL, "no TLS library. session=" << (void*)s.get() << " data=" << (void*)data.get());
#endif
+ debugs(83, 5, "session=" << (void*)s.get() << " data=" << (void*)data.get());
+ } else {
+ debugs(83, 5, "session=" << (void*)s.get() << " no resume data");
}
}
return false;
}
+#if USE_OPENSSL
+static int
+store_session_cb(SSL *ssl, SSL_SESSION *session)
+{
+ if (!SessionCache)
+ return 0;
+
+ debugs(83, 5, "Request to store SSL_SESSION");
+
+ SSL_SESSION_set_timeout(session, Config.SSL.session_ttl);
+
+ unsigned int idlen;
+ const unsigned char *id = SSL_SESSION_get_id(session, &idlen);
+ // XXX: the other calls [to openForReading()] do not copy the sessionId to a char buffer, does this really have to?
+ unsigned char key[MEMMAP_SLOT_KEY_SIZE];
+ // Session ids are of size 32bytes. They should always fit to a
+ // MemMap::Slot::key
+ assert(idlen <= MEMMAP_SLOT_KEY_SIZE);
+ memset(key, 0, sizeof(key));
+ memcpy(key, id, idlen);
+ int pos;
+ if (auto slotW = SessionCache->openForWriting(static_cast<const cache_key*>(key), pos)) {
+ int lenRequired = i2d_SSL_SESSION(session, nullptr);
+ if (lenRequired < MEMMAP_SLOT_DATA_SIZE) {
+ unsigned char *p = static_cast<unsigned char *>(slotW->p);
+ lenRequired = i2d_SSL_SESSION(session, &p);
+ slotW->set(key, nullptr, lenRequired, squid_curtime + Config.SSL.session_ttl);
+ }
+ SessionCache->closeForWriting(pos);
+ debugs(83, 5, "wrote an SSL_SESSION entry of size " << lenRequired << " at pos " << pos);
+ }
+ return 0;
+}
+
+static void
+remove_session_cb(SSL_CTX *, SSL_SESSION *sessionID)
+{
+ if (!SessionCache)
+ return;
+
+ debugs(83, 5, "Request to remove corrupted or not valid SSL_SESSION");
+ int pos;
+ if (SessionCache->openForReading(reinterpret_cast<const cache_key*>(sessionID), pos)) {
+ SessionCache->closeForReading(pos);
+ // TODO:
+ // What if we are not able to remove the session?
+ // Maybe schedule a job to remove it later?
+ // For now we just have an invalid entry in cache until will be expired
+ // The OpenSSL library will reject it when we try to use it
+ SessionCache->free(pos);
+ }
+}
+
+static SSL_SESSION *
+#if SQUID_USE_CONST_SSL_SESSION_CBID
+get_session_cb(SSL *, const unsigned char *sessionID, int len, int *copy)
+#else
+get_session_cb(SSL *, unsigned char *sessionID, int len, int *copy)
+#endif
+{
+ if (!SessionCache)
+ return nullptr;
+
+ const unsigned int *p = reinterpret_cast<const unsigned int *>(sessionID);
+ debugs(83, 5, "Request to search for SSL_SESSION of len: " <<
+ len << p[0] << ":" << p[1]);
+
+ SSL_SESSION *session = nullptr;
+ int pos;
+ if (const auto slot = SessionCache->openForReading(static_cast<const cache_key*>(sessionID), pos)) {
+ if (slot->expire > squid_curtime) {
+ const unsigned char *ptr = slot->p;
+ session = d2i_SSL_SESSION(nullptr, &ptr, slot->pSize);
+ debugs(83, 5, "SSL_SESSION retrieved from cache at pos " << pos);
+ } else
+ debugs(83, 5, "SSL_SESSION in cache expired");
+ SessionCache->closeForReading(pos);
+ }
+
+ if (!session)
+ debugs(83, 5, "Failed to retrieve SSL_SESSION from cache");
+
+ // With the parameter copy the callback can require the SSL engine
+ // to increment the reference count of the SSL_SESSION object, Normally
+ // the reference count is not incremented and therefore the session must
+ // not be explicitly freed with SSL_SESSION_free(3).
+ *copy = 0;
+ return session;
+}
+
+void
+Security::SetSessionCacheCallbacks(Security::ContextPointer &ctx)
+{
+ if (SessionCache) {
+ SSL_CTX_set_session_cache_mode(ctx.get(), SSL_SESS_CACHE_SERVER|SSL_SESS_CACHE_NO_INTERNAL);
+ SSL_CTX_sess_set_new_cb(ctx.get(), store_session_cb);
+ SSL_CTX_sess_set_remove_cb(ctx.get(), remove_session_cb);
+ SSL_CTX_sess_set_get_cb(ctx.get(), get_session_cb);
+ }
+}
+#endif /* USE_OPENSSL */
+
void
initializeSessionCache()
{
int configuredItems = ::Config.SSL.sessionCacheSize / sizeof(Ipc::MemMap::Slot);
if (IamWorkerProcess() && configuredItems)
- Ssl::SessionCache = new Ipc::MemMap(Ssl::SessionCacheName);
+ SessionCache = new Ipc::MemMap(SessionCacheName);
else {
- Ssl::SessionCache = nullptr;
+ SessionCache = nullptr;
return;
}
for (AnyP::PortCfgPointer s = HttpPortList; s != nullptr; s = s->next) {
- if (s->secure.staticContext.get())
- Ssl::SetSessionCallbacks(s->secure.staticContext.get());
+ if (s->secure.staticContext)
+ Security::SetSessionCacheCallbacks(s->secure.staticContext);
}
#endif
}
void
SharedSessionCacheRr::useConfig()
{
-#if USE_OPENSSL // while Ssl:: bits in use
- if (Ssl::SessionCache || !isTlsServer()) //no need to configure ssl session cache.
+#if USE_OPENSSL
+ if (SessionCache || !isTlsServer()) // no need to configure SSL_SESSION* cache.
return;
Ipc::Mem::RegisteredRunner::useConfig();
void
SharedSessionCacheRr::create()
{
- if (!isTlsServer()) //no need to configure ssl session cache.
+ if (!isTlsServer()) // no need to configure SSL_SESSION* cache.
return;
-#if USE_OPENSSL // while Ssl:: bits in use
+#if USE_OPENSSL
if (int items = Config.SSL.sessionCacheSize / sizeof(Ipc::MemMap::Slot))
- owner = Ipc::MemMap::Init(Ssl::SessionCacheName, items);
+ owner = Ipc::MemMap::Init(SessionCacheName, items);
#endif
}
SharedSessionCacheRr::~SharedSessionCacheRr()
{
// XXX: Enable after testing to reduce at-exit memory "leaks".
- // delete Ssl::SessionCache;
+ // delete SessionCache;
delete owner;
}