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[user/henk/code/inspircd.git] / src / modules / extra / m_ssl_openssl.cpp
index 7a8bdeeb00be52936a208dc2760a2a377516e878..8467cc6d416b5931efb721009aeca33611e7ea60 100644 (file)
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
- /* HACK: This prevents OpenSSL on OS X 10.7 and later from spewing deprecation
-  * warnings for every single function call. As far as I (SaberUK) know, Apple
-  * have no plans to remove OpenSSL so this warning just causes needless spam.
-  */
-#ifdef __APPLE__
-# define __AVAILABILITYMACROS__
-# define DEPRECATED_IN_MAC_OS_X_VERSION_10_7_AND_LATER
-#endif
 
 #include "inspircd.h"
 #include "iohook.h"
+#include "modules/ssl.h"
+
+// Ignore OpenSSL deprecation warnings on OS X Lion and newer.
+#if defined __APPLE__
+# pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#endif
+
+// Fix warnings about the use of `long long` on C++03.
+#if defined __clang__
+# pragma clang diagnostic ignored "-Wc++11-long-long"
+#elif defined __GNUC__
+# pragma GCC diagnostic ignored "-Wlong-long"
+#endif
+
 #include <openssl/ssl.h>
 #include <openssl/err.h>
-#include "modules/ssl.h"
 
 #ifdef _WIN32
-# pragma comment(lib, "libcrypto.lib")
-# pragma comment(lib, "libssl.lib")
-# pragma comment(lib, "user32.lib")
-# pragma comment(lib, "advapi32.lib")
-# pragma comment(lib, "libgcc.lib")
-# pragma comment(lib, "libmingwex.lib")
-# pragma comment(lib, "gdi32.lib")
-# undef MAX_DESCRIPTORS
-# define MAX_DESCRIPTORS 10000
+# pragma comment(lib, "ssleay32.lib")
+# pragma comment(lib, "libeay32.lib")
 #endif
 
-/* $CompileFlags: pkgconfversion("openssl","0.9.7") pkgconfincludes("openssl","/openssl/ssl.h","") -Wno-pedantic */
+/* $CompileFlags: pkgconfversion("openssl","0.9.7") pkgconfincludes("openssl","/openssl/ssl.h","") */
 /* $LinkerFlags: rpath("pkg-config --libs openssl") pkgconflibs("openssl","/libssl.so","-lssl -lcrypto") */
 
+#if ((OPENSSL_VERSION_NUMBER >= 0x10000000L) && (!(defined(OPENSSL_NO_ECDH))))
+// OpenSSL 0.9.8 includes some ECC support, but it's unfinished. Enable only for 1.0.0 and later.
+#define INSPIRCD_OPENSSL_ENABLE_ECDH
+#endif
+
 enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
 
 static bool SelfSigned = false;
+static int exdataindex;
 
 char* get_error()
 {
@@ -61,6 +65,7 @@ char* get_error()
 }
 
 static int OnVerify(int preverify_ok, X509_STORE_CTX* ctx);
+static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
 
 namespace OpenSSL
 {
@@ -78,12 +83,13 @@ namespace OpenSSL
         public:
                DHParams(const std::string& filename)
                {
-                       FILE* dhpfile = fopen(filename.c_str(), "r");
+                       BIO* dhpfile = BIO_new_file(filename.c_str(), "r");
                        if (dhpfile == NULL)
-                               throw Exception("Couldn't open DH file " + filename + ": " + strerror(errno));
+                               throw Exception("Couldn't open DH file " + filename);
+
+                       dh = PEM_read_bio_DHparams(dhpfile, NULL, NULL, NULL);
+                       BIO_free(dhpfile);
 
-                       dh = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
-                       fclose(dhpfile);
                        if (!dh)
                                throw Exception("Couldn't read DH params from file " + filename);
                }
@@ -102,16 +108,33 @@ namespace OpenSSL
        class Context
        {
                SSL_CTX* const ctx;
+               long ctx_options;
 
         public:
                Context(SSL_CTX* context)
                        : ctx(context)
                {
-                       SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
-                       SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
+                       // Sane default options for OpenSSL see https://www.openssl.org/docs/ssl/SSL_CTX_set_options.html
+                       // and when choosing a cipher, use the server's preferences instead of the client preferences.
+                       long opts = SSL_OP_NO_SSLv2 | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION | SSL_OP_CIPHER_SERVER_PREFERENCE | SSL_OP_SINGLE_DH_USE;
+                       // Only turn options on if they exist
+#ifdef SSL_OP_SINGLE_ECDH_USE
+                       opts |= SSL_OP_SINGLE_ECDH_USE;
+#endif
+#ifdef SSL_OP_NO_TICKET
+                       opts |= SSL_OP_NO_TICKET;
+#endif
 
-                       const unsigned char session_id[] = "inspircd";
-                       SSL_CTX_set_session_id_context(ctx, session_id, sizeof(session_id) - 1);
+                       ctx_options = SSL_CTX_set_options(ctx, opts);
+
+                       long mode = SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER;
+#ifdef SSL_MODE_RELEASE_BUFFERS
+                       mode |= SSL_MODE_RELEASE_BUFFERS;
+#endif
+                       SSL_CTX_set_mode(ctx, mode);
+                       SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL);
+                       SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
+                       SSL_CTX_set_info_callback(ctx, StaticSSLInfoCallback);
                }
 
                ~Context()
@@ -121,32 +144,85 @@ namespace OpenSSL
 
                bool SetDH(DHParams& dh)
                {
+                       ERR_clear_error();
                        return (SSL_CTX_set_tmp_dh(ctx, dh.get()) >= 0);
                }
 
+#ifdef INSPIRCD_OPENSSL_ENABLE_ECDH
+               void SetECDH(const std::string& curvename)
+               {
+                       int nid = OBJ_sn2nid(curvename.c_str());
+                       if (nid == 0)
+                               throw Exception("Unknown curve: " + curvename);
+
+                       EC_KEY* eckey = EC_KEY_new_by_curve_name(nid);
+                       if (!eckey)
+                               throw Exception("Unable to create EC key object");
+
+                       ERR_clear_error();
+                       bool ret = (SSL_CTX_set_tmp_ecdh(ctx, eckey) >= 0);
+                       EC_KEY_free(eckey);
+                       if (!ret)
+                               throw Exception("Couldn't set ECDH parameters");
+               }
+#endif
+
                bool SetCiphers(const std::string& ciphers)
                {
+                       ERR_clear_error();
                        return SSL_CTX_set_cipher_list(ctx, ciphers.c_str());
                }
 
                bool SetCerts(const std::string& filename)
                {
+                       ERR_clear_error();
                        return SSL_CTX_use_certificate_chain_file(ctx, filename.c_str());
                }
 
                bool SetPrivateKey(const std::string& filename)
                {
+                       ERR_clear_error();
                        return SSL_CTX_use_PrivateKey_file(ctx, filename.c_str(), SSL_FILETYPE_PEM);
                }
 
                bool SetCA(const std::string& filename)
                {
+                       ERR_clear_error();
                        return SSL_CTX_load_verify_locations(ctx, filename.c_str(), 0);
                }
 
-               SSL* CreateSession()
+               long GetDefaultContextOptions() const
                {
-                       return SSL_new(ctx);
+                       return ctx_options;
+               }
+
+               long SetRawContextOptions(long setoptions, long clearoptions)
+               {
+                       // Clear everything
+                       SSL_CTX_clear_options(ctx, SSL_CTX_get_options(ctx));
+
+                       // Set the default options and what is in the conf
+                       SSL_CTX_set_options(ctx, ctx_options | setoptions);
+                       return SSL_CTX_clear_options(ctx, clearoptions);
+               }
+
+               void SetVerifyCert()
+               {
+                       SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
+               }
+
+               SSL* CreateServerSession()
+               {
+                       SSL* sess = SSL_new(ctx);
+                       SSL_set_accept_state(sess); // Act as server
+                       return sess;
+               }
+
+               SSL* CreateClientSession()
+               {
+                       SSL* sess = SSL_new(ctx);
+                       SSL_set_connect_state(sess); // Act as client
+                       return sess;
                }
        };
 
@@ -173,6 +249,14 @@ namespace OpenSSL
                 */
                std::string lasterr;
 
+               /** True if renegotiations are allowed, false if not
+                */
+               const bool allowrenego;
+
+               /** Rough max size of records to send
+                */
+               const unsigned int outrecsize;
+
                static int error_callback(const char* str, size_t len, void* u)
                {
                        Profile* profile = reinterpret_cast<Profile*>(u);
@@ -180,12 +264,40 @@ namespace OpenSSL
                        return 0;
                }
 
+               /** Set raw OpenSSL context (SSL_CTX) options from a config tag
+                * @param ctxname Name of the context, client or server
+                * @param tag Config tag defining this profile
+                * @param context Context object to manipulate
+                */
+               void SetContextOptions(const std::string& ctxname, ConfigTag* tag, Context& context)
+               {
+                       long setoptions = tag->getInt(ctxname + "setoptions");
+                       long clearoptions = tag->getInt(ctxname + "clearoptions");
+#ifdef SSL_OP_NO_COMPRESSION
+                       if (!tag->getBool("compression", false)) // Disable compression by default
+                               setoptions |= SSL_OP_NO_COMPRESSION;
+#endif
+                       if (!tag->getBool("sslv3", false)) // Disable SSLv3 by default
+                               setoptions |= SSL_OP_NO_SSLv3;
+                       if (!tag->getBool("tlsv1", true))
+                               setoptions |= SSL_OP_NO_TLSv1;
+
+                       if (!setoptions && !clearoptions)
+                               return; // Nothing to do
+
+                       ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Setting %s %s context options, default: %ld set: %ld clear: %ld", name.c_str(), ctxname.c_str(), ctx.GetDefaultContextOptions(), setoptions, clearoptions);
+                       long final = context.SetRawContextOptions(setoptions, clearoptions);
+                       ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "%s %s context options: %ld", name.c_str(), ctxname.c_str(), final);
+               }
+
         public:
                Profile(const std::string& profilename, ConfigTag* tag)
                        : name(profilename)
                        , dh(ServerInstance->Config->Paths.PrependConfig(tag->getString("dhfile", "dh.pem")))
                        , ctx(SSL_CTX_new(SSLv23_server_method()))
                        , clictx(SSL_CTX_new(SSLv23_client_method()))
+                       , allowrenego(tag->getBool("renegotiation")) // Disallow by default
+                       , outrecsize(tag->getInt("outrecsize", 2048, 512, 16384))
                {
                        if ((!ctx.SetDH(dh)) || (!clictx.SetDH(dh)))
                                throw Exception("Couldn't set DH parameters");
@@ -205,6 +317,15 @@ namespace OpenSSL
                                }
                        }
 
+#ifdef INSPIRCD_OPENSSL_ENABLE_ECDH
+                       std::string curvename = tag->getString("ecdhcurve", "prime256v1");
+                       if (!curvename.empty())
+                               ctx.SetECDH(curvename);
+#endif
+
+                       SetContextOptions("server", tag, ctx);
+                       SetContextOptions("client", tag, clictx);
+
                        /* Load our keys and certificates
                         * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
                         */
@@ -229,15 +350,62 @@ namespace OpenSSL
                                ERR_print_errors_cb(error_callback, this);
                                ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Can't read CA list from %s. This is only a problem if you want to verify client certificates, otherwise it's safe to ignore this message. Error: %s", filename.c_str(), lasterr.c_str());
                        }
+
+                       clictx.SetVerifyCert();
+                       if (tag->getBool("requestclientcert", true))
+                               ctx.SetVerifyCert();
                }
 
                const std::string& GetName() const { return name; }
-               SSL* CreateServerSession() { return ctx.CreateSession(); }
-               SSL* CreateClientSession() { return clictx.CreateSession(); }
+               SSL* CreateServerSession() { return ctx.CreateServerSession(); }
+               SSL* CreateClientSession() { return clictx.CreateClientSession(); }
                const EVP_MD* GetDigest() { return digest; }
+               bool AllowRenegotiation() const { return allowrenego; }
+               unsigned int GetOutgoingRecordSize() const { return outrecsize; }
        };
+
+       namespace BIOMethod
+       {
+               static int create(BIO* bio)
+               {
+                       bio->init = 1;
+                       return 1;
+               }
+
+               static int destroy(BIO* bio)
+               {
+                       // XXX: Dummy function to avoid a memory leak in OpenSSL.
+                       // The memory leak happens in BIO_free() (bio_lib.c) when the destroy func of the BIO is NULL.
+                       // This is fixed in OpenSSL but some distros still ship the unpatched version hence we provide this workaround.
+                       return 1;
+               }
+
+               static long ctrl(BIO* bio, int cmd, long num, void* ptr)
+               {
+                       if (cmd == BIO_CTRL_FLUSH)
+                               return 1;
+                       return 0;
+               }
+
+               static int read(BIO* bio, char* buf, int len);
+               static int write(BIO* bio, const char* buf, int len);
+       }
 }
 
+static BIO_METHOD biomethods =
+{
+       (100 | BIO_TYPE_SOURCE_SINK),
+       "inspircd",
+       OpenSSL::BIOMethod::write,
+       OpenSSL::BIOMethod::read,
+       NULL, // puts
+       NULL, // gets
+       OpenSSL::BIOMethod::ctrl,
+       OpenSSL::BIOMethod::create,
+       OpenSSL::BIOMethod::destroy, // destroy, does nothing, see function body for more info
+       NULL // callback_ctrl
+};
+
 static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
 {
        /* XXX: This will allow self signed certificates.
@@ -257,19 +425,14 @@ class OpenSSLIOHook : public SSLIOHook
  private:
        SSL* sess;
        issl_status status;
-       const bool outbound;
        bool data_to_write;
        reference<OpenSSL::Profile> profile;
 
-       bool Handshake(StreamSocket* user)
+       // Returns 1 if handshake succeeded, 0 if it is still in progress, -1 if it failed
+       int Handshake(StreamSocket* user)
        {
-               int ret;
-
-               if (outbound)
-                       ret = SSL_connect(sess);
-               else
-                       ret = SSL_accept(sess);
-
+               ERR_clear_error();
+               int ret = SSL_do_handshake(sess);
                if (ret < 0)
                {
                        int err = SSL_get_error(sess, ret);
@@ -278,20 +441,19 @@ class OpenSSLIOHook : public SSLIOHook
                        {
                                SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
                                this->status = ISSL_HANDSHAKING;
-                               return true;
+                               return 0;
                        }
                        else if (err == SSL_ERROR_WANT_WRITE)
                        {
                                SocketEngine::ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
                                this->status = ISSL_HANDSHAKING;
-                               return true;
+                               return 0;
                        }
                        else
                        {
                                CloseSession();
+                               return -1;
                        }
-
-                       return false;
                }
                else if (ret > 0)
                {
@@ -302,15 +464,13 @@ class OpenSSLIOHook : public SSLIOHook
 
                        SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
 
-                       return true;
+                       return 1;
                }
                else if (ret == 0)
                {
                        CloseSession();
-                       return true;
                }
-
-               return true;
+               return -1;
        }
 
        void CloseSession()
@@ -323,7 +483,6 @@ class OpenSSLIOHook : public SSLIOHook
                sess = NULL;
                certificate = NULL;
                status = ISSL_NONE;
-               errno = EIO;
        }
 
        void VerifyCertificate()
@@ -358,8 +517,14 @@ class OpenSSLIOHook : public SSLIOHook
                char buf[512];
                X509_NAME_oneline(X509_get_subject_name(cert), buf, sizeof(buf));
                certinfo->dn = buf;
+               // Make sure there are no chars in the string that we consider invalid
+               if (certinfo->dn.find_first_of("\r\n") != std::string::npos)
+                       certinfo->dn.clear();
+
                X509_NAME_oneline(X509_get_issuer_name(cert), buf, sizeof(buf));
                certinfo->issuer = buf;
+               if (certinfo->issuer.find_first_of("\r\n") != std::string::npos)
+                       certinfo->issuer.clear();
 
                if (!X509_digest(cert, profile->GetDigest(), md, &n))
                {
@@ -378,20 +543,65 @@ class OpenSSLIOHook : public SSLIOHook
                X509_free(cert);
        }
 
+       void SSLInfoCallback(int where, int rc)
+       {
+               if ((where & SSL_CB_HANDSHAKE_START) && (status == ISSL_OPEN))
+               {
+                       if (profile->AllowRenegotiation())
+                               return;
+
+                       // The other side is trying to renegotiate, kill the connection and change status
+                       // to ISSL_NONE so CheckRenego() closes the session
+                       status = ISSL_NONE;
+                       BIO* bio = SSL_get_rbio(sess);
+                       EventHandler* eh = static_cast<StreamSocket*>(bio->ptr);
+                       SocketEngine::Shutdown(eh, 2);
+               }
+       }
+
+       bool CheckRenego(StreamSocket* sock)
+       {
+               if (status != ISSL_NONE)
+                       return true;
+
+               ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Session %p killed, attempted to renegotiate", (void*)sess);
+               CloseSession();
+               sock->SetError("Renegotiation is not allowed");
+               return false;
+       }
+
+       // Returns 1 if application I/O should proceed, 0 if it must wait for the underlying protocol to progress, -1 on fatal error
+       int PrepareIO(StreamSocket* sock)
+       {
+               if (status == ISSL_OPEN)
+                       return 1;
+               else if (status == ISSL_HANDSHAKING)
+               {
+                       // The handshake isn't finished, try to finish it
+                       return Handshake(sock);
+               }
+
+               CloseSession();
+               return -1;
+       }
+
+       // Calls our private SSLInfoCallback()
+       friend void StaticSSLInfoCallback(const SSL* ssl, int where, int rc);
+
  public:
-       OpenSSLIOHook(IOHookProvider* hookprov, StreamSocket* sock, bool is_outbound, SSL* session, const reference<OpenSSL::Profile>& sslprofile)
+       OpenSSLIOHook(IOHookProvider* hookprov, StreamSocket* sock, SSL* session, const reference<OpenSSL::Profile>& sslprofile)
                : SSLIOHook(hookprov)
                , sess(session)
                , status(ISSL_NONE)
-               , outbound(is_outbound)
                , data_to_write(false)
                , profile(sslprofile)
        {
-               if (sess == NULL)
-                       return;
-               if (SSL_set_fd(sess, sock->GetFd()) == 0)
-                       throw ModuleException("Can't set fd with SSL_set_fd: " + ConvToStr(sock->GetFd()));
+               // Create BIO instance and store a pointer to the socket in it which will be used by the read and write functions
+               BIO* bio = BIO_new(&biomethods);
+               bio->ptr = sock;
+               SSL_set_bio(sess, bio, bio);
 
+               SSL_set_ex_data(sess, exdataindex, this);
                sock->AddIOHook(this);
                Handshake(sock);
        }
@@ -403,37 +613,32 @@ class OpenSSLIOHook : public SSLIOHook
 
        int OnStreamSocketRead(StreamSocket* user, std::string& recvq) CXX11_OVERRIDE
        {
-               if (!sess)
-               {
-                       CloseSession();
-                       return -1;
-               }
-
-               if (status == ISSL_HANDSHAKING)
-               {
-                       // The handshake isn't finished and it wants to read, try to finish it.
-                       if (!Handshake(user))
-                       {
-                               // Couldn't resume handshake.
-                               if (status == ISSL_NONE)
-                                       return -1;
-                               return 0;
-                       }
-               }
+               // Finish handshake if needed
+               int prepret = PrepareIO(user);
+               if (prepret <= 0)
+                       return prepret;
 
                // If we resumed the handshake then this->status will be ISSL_OPEN
-
-               if (status == ISSL_OPEN)
                {
+                       ERR_clear_error();
                        char* buffer = ServerInstance->GetReadBuffer();
                        size_t bufsiz = ServerInstance->Config->NetBufferSize;
                        int ret = SSL_read(sess, buffer, bufsiz);
 
+                       if (!CheckRenego(user))
+                               return -1;
+
                        if (ret > 0)
                        {
                                recvq.append(buffer, ret);
+                               int mask = 0;
+                               // Schedule a read if there is still data in the OpenSSL buffer
+                               if (SSL_pending(sess) > 0)
+                                       mask |= FD_ADD_TRIAL_READ;
                                if (data_to_write)
-                                       SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_SINGLE_WRITE);
+                                       mask |= FD_WANT_POLL_READ | FD_WANT_SINGLE_WRITE;
+                               if (mask != 0)
+                                       SocketEngine::ChangeEventMask(user, mask);
                                return 1;
                        }
                        else if (ret == 0)
@@ -443,7 +648,7 @@ class OpenSSLIOHook : public SSLIOHook
                                user->SetError("Connection closed");
                                return -1;
                        }
-                       else if (ret < 0)
+                       else // if (ret < 0)
                        {
                                int err = SSL_get_error(sess, ret);
 
@@ -464,43 +669,36 @@ class OpenSSLIOHook : public SSLIOHook
                                }
                        }
                }
-
-               return 0;
        }
 
-       int OnStreamSocketWrite(StreamSocket* user, std::string& buffer) CXX11_OVERRIDE
+       int OnStreamSocketWrite(StreamSocket* user, StreamSocket::SendQueue& sendq) CXX11_OVERRIDE
        {
-               if (!sess)
-               {
-                       CloseSession();
-                       return -1;
-               }
+               // Finish handshake if needed
+               int prepret = PrepareIO(user);
+               if (prepret <= 0)
+                       return prepret;
 
                data_to_write = true;
 
-               if (status == ISSL_HANDSHAKING)
-               {
-                       if (!Handshake(user))
-                       {
-                               // Couldn't resume handshake.
-                               if (status == ISSL_NONE)
-                                       return -1;
-                               return 0;
-                       }
-               }
-
-               if (status == ISSL_OPEN)
+               // Session is ready for transferring application data
+               while (!sendq.empty())
                {
+                       ERR_clear_error();
+                       FlattenSendQueue(sendq, profile->GetOutgoingRecordSize());
+                       const StreamSocket::SendQueue::Element& buffer = sendq.front();
                        int ret = SSL_write(sess, buffer.data(), buffer.size());
+
+                       if (!CheckRenego(user))
+                               return -1;
+
                        if (ret == (int)buffer.length())
                        {
-                               data_to_write = false;
-                               SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
-                               return 1;
+                               // Wrote entire record, continue sending
+                               sendq.pop_front();
                        }
                        else if (ret > 0)
                        {
-                               buffer = buffer.substr(ret);
+                               sendq.erase_front(ret);
                                SocketEngine::ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
                                return 0;
                        }
@@ -509,7 +707,7 @@ class OpenSSLIOHook : public SSLIOHook
                                CloseSession();
                                return -1;
                        }
-                       else if (ret < 0)
+                       else // if (ret < 0)
                        {
                                int err = SSL_get_error(sess, ret);
 
@@ -530,23 +728,75 @@ class OpenSSLIOHook : public SSLIOHook
                                }
                        }
                }
-               return 0;
+
+               data_to_write = false;
+               SocketEngine::ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
+               return 1;
        }
 
-       void TellCiphersAndFingerprint(LocalUser* user)
+       void GetCiphersuite(std::string& out) const CXX11_OVERRIDE
        {
-               if (sess)
-               {
-                       std::string text = "*** You are connected using SSL cipher '" + std::string(SSL_get_cipher(sess)) + "'";
-                       const std::string& fingerprint = certificate->fingerprint;
-                       if (!fingerprint.empty())
-                               text += " and your SSL fingerprint is " + fingerprint;
-
-                       user->WriteNotice(text);
-               }
+               if (!IsHandshakeDone())
+                       return;
+               out.append(SSL_get_version(sess)).push_back('-');
+               out.append(SSL_get_cipher(sess));
        }
+
+       bool IsHandshakeDone() const { return (status == ISSL_OPEN); }
 };
 
+static void StaticSSLInfoCallback(const SSL* ssl, int where, int rc)
+{
+       OpenSSLIOHook* hook = static_cast<OpenSSLIOHook*>(SSL_get_ex_data(ssl, exdataindex));
+       hook->SSLInfoCallback(where, rc);
+}
+
+static int OpenSSL::BIOMethod::write(BIO* bio, const char* buffer, int size)
+{
+       BIO_clear_retry_flags(bio);
+
+       StreamSocket* sock = static_cast<StreamSocket*>(bio->ptr);
+       if (sock->GetEventMask() & FD_WRITE_WILL_BLOCK)
+       {
+               // Writes blocked earlier, don't retry syscall
+               BIO_set_retry_write(bio);
+               return -1;
+       }
+
+       int ret = SocketEngine::Send(sock, buffer, size, 0);
+       if ((ret < size) && ((ret > 0) || (SocketEngine::IgnoreError())))
+       {
+               // Blocked, set retry flag for OpenSSL
+               SocketEngine::ChangeEventMask(sock, FD_WRITE_WILL_BLOCK);
+               BIO_set_retry_write(bio);
+       }
+
+       return ret;
+}
+
+static int OpenSSL::BIOMethod::read(BIO* bio, char* buffer, int size)
+{
+       BIO_clear_retry_flags(bio);
+
+       StreamSocket* sock = static_cast<StreamSocket*>(bio->ptr);
+       if (sock->GetEventMask() & FD_READ_WILL_BLOCK)
+       {
+               // Reads blocked earlier, don't retry syscall
+               BIO_set_retry_read(bio);
+               return -1;
+       }
+
+       int ret = SocketEngine::Recv(sock, buffer, size, 0);
+       if ((ret < size) && ((ret > 0) || (SocketEngine::IgnoreError())))
+       {
+               // Blocked, set retry flag for OpenSSL
+               SocketEngine::ChangeEventMask(sock, FD_READ_WILL_BLOCK);
+               BIO_set_retry_read(bio);
+       }
+
+       return ret;
+}
+
 class OpenSSLIOHookProvider : public refcountbase, public IOHookProvider
 {
        reference<OpenSSL::Profile> profile;
@@ -566,12 +816,12 @@ class OpenSSLIOHookProvider : public refcountbase, public IOHookProvider
 
        void OnAccept(StreamSocket* sock, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server) CXX11_OVERRIDE
        {
-               new OpenSSLIOHook(this, sock, false, profile->CreateServerSession(), profile);
+               new OpenSSLIOHook(this, sock, profile->CreateServerSession(), profile);
        }
 
        void OnConnect(StreamSocket* sock) CXX11_OVERRIDE
        {
-               new OpenSSLIOHook(this, sock, true, profile->CreateClientSession(), profile);
+               new OpenSSLIOHook(this, sock, profile->CreateClientSession(), profile);
        }
 };
 
@@ -642,6 +892,14 @@ class ModuleSSLOpenSSL : public Module
 
        void init() CXX11_OVERRIDE
        {
+               ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "OpenSSL lib version \"%s\" module was compiled for \"" OPENSSL_VERSION_TEXT "\"", SSLeay_version(SSLEAY_VERSION));
+
+               // Register application specific data
+               char exdatastr[] = "inspircd";
+               exdataindex = SSL_get_ex_new_index(0, exdatastr, NULL, NULL, NULL);
+               if (exdataindex < 0)
+                       throw ModuleException("Failed to register application specific data");
+
                ReadProfiles();
        }
 
@@ -660,20 +918,13 @@ class ModuleSSLOpenSSL : public Module
                }
        }
 
-       void OnUserConnect(LocalUser* user) CXX11_OVERRIDE
-       {
-               IOHook* hook = user->eh.GetIOHook();
-               if (hook && hook->prov->creator == this)
-                       static_cast<OpenSSLIOHook*>(hook)->TellCiphersAndFingerprint(user);
-       }
-
        void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
        {
                if (target_type == TYPE_USER)
                {
                        LocalUser* user = IS_LOCAL((User*)item);
 
-                       if (user && user->eh.GetIOHook() && user->eh.GetIOHook()->prov->creator == this)
+                       if ((user) && (user->eh.GetModHook(this)))
                        {
                                // User is using SSL, they're a local user, and they're using one of *our* SSL ports.
                                // Potentially there could be multiple SSL modules loaded at once on different ports.
@@ -682,6 +933,14 @@ class ModuleSSLOpenSSL : public Module
                }
        }
 
+       ModResult OnCheckReady(LocalUser* user) CXX11_OVERRIDE
+       {
+               const OpenSSLIOHook* const iohook = static_cast<OpenSSLIOHook*>(user->eh.GetModHook(this));
+               if ((iohook) && (!iohook->IsHandshakeDone()))
+                       return MOD_RES_DENY;
+               return MOD_RES_PASSTHRU;
+       }
+
        Version GetVersion() CXX11_OVERRIDE
        {
                return Version("Provides SSL support for clients", VF_VENDOR);