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m_ssl_openssl.cpp

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/*       +------------------------------------+
 *       | Inspire Internet Relay Chat Daemon |
 *       +------------------------------------+
 *
 *  InspIRCd: (C) 2002-2008 InspIRCd Development Team
 * See: http://www.inspircd.org/wiki/index.php/Credits
 *
 * This program is free but copyrighted software; see
 *            the file COPYING for details.
 *
 * ---------------------------------------------------
 */

#include "inspircd.h"

#include <openssl/ssl.h>
#include <openssl/err.h>

#include "configreader.h"
#include "users.h"
#include "channels.h"
#include "modules.h"

#include "socket.h"
#include "hashcomp.h"

#include "transport.h"

#ifdef WINDOWS
#pragma comment(lib, "libeay32MTd")
#pragma comment(lib, "ssleay32MTd")
#undef MAX_DESCRIPTORS
#define MAX_DESCRIPTORS 10000
#endif

/* $ModDesc: Provides SSL support for clients */

/* $LinkerFlags: if("USE_FREEBSD_BASE_SSL") -lssl -lcrypto */
/* $CompileFlags: if(!"USE_FREEBSD_BASE_SSL") pkgconfversion("openssl","0.9.7") pkgconfincludes("openssl","/openssl/ssl.h","") */
/* $LinkerFlags: if(!"USE_FREEBSD_BASE_SSL") rpath("pkg-config --libs openssl") pkgconflibs("openssl","/libssl.so","-lssl -lcrypto -ldl") */

/* $ModDep: transport.h */
/* $NoPedantic */
/* $CopyInstall: conf/key.pem $(CONPATH) */
/* $CopyInstall: conf/cert.pem $(CONPATH) */


enum issl_status { ISSL_NONE, ISSL_HANDSHAKING, ISSL_OPEN };
enum issl_io_status { ISSL_WRITE, ISSL_READ };

static bool SelfSigned = false;

bool isin(const std::string &host, int port, const std::vector<std::string> &portlist)
{
        if (std::find(portlist.begin(), portlist.end(), "*:" + ConvToStr(port)) != portlist.end())
                return true;

        if (std::find(portlist.begin(), portlist.end(), ":" + ConvToStr(port)) != portlist.end())
                return true;

        return std::find(portlist.begin(), portlist.end(), host + ":" + ConvToStr(port)) != portlist.end();
}

char* get_error()
{
        return ERR_error_string(ERR_get_error(), NULL);
}

static int error_callback(const char *str, size_t len, void *u);

class issl_session : public classbase
{
public:
        SSL* sess;
        issl_status status;
        issl_io_status rstat;
        issl_io_status wstat;

        unsigned int inbufoffset;
        char* inbuf;                    // Buffer OpenSSL reads into.
        std::string outbuf;     // Buffer for outgoing data that OpenSSL will not take.
        int fd;
        bool outbound;

        issl_session()
        {
                outbound = false;
                rstat = ISSL_READ;
                wstat = ISSL_WRITE;
        }
};

static int OnVerify(int preverify_ok, X509_STORE_CTX *ctx)
{
        /* XXX: This will allow self signed certificates.
         * In the future if we want an option to not allow this,
         * we can just return preverify_ok here, and openssl
         * will boot off self-signed and invalid peer certs.
         */
        int ve = X509_STORE_CTX_get_error(ctx);

        SelfSigned = (ve == X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT);

        return 1;
}

class ModuleSSLOpenSSL : public Module
{
        std::vector<std::string> listenports;

        int inbufsize;
        issl_session* sessions;

        SSL_CTX* ctx;
        SSL_CTX* clictx;

        char* dummy;
        char cipher[MAXBUF];

        std::string keyfile;
        std::string certfile;
        std::string cafile;
        // std::string crlfile;
        std::string dhfile;
        std::string sslports;

        int clientactive;

 public:

        InspIRCd* PublicInstance;

        ModuleSSLOpenSSL(InspIRCd* Me)
        : Module(Me), PublicInstance(Me)
        {
                ServerInstance->Modules->PublishInterface("BufferedSocketHook", this);

                sessions = new issl_session[ServerInstance->SE->GetMaxFds()];

                // Not rehashable...because I cba to reduce all the sizes of existing buffers.
                inbufsize = ServerInstance->Config->NetBufferSize;

                /* Global SSL library initialization*/
                SSL_library_init();
                SSL_load_error_strings();

                /* Build our SSL contexts:
                 * NOTE: OpenSSL makes us have two contexts, one for servers and one for clients. ICK.
                 */
                ctx = SSL_CTX_new( SSLv23_server_method() );
                clictx = SSL_CTX_new( SSLv23_client_method() );

                SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);
                SSL_CTX_set_mode(clictx, SSL_MODE_ENABLE_PARTIAL_WRITE | SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER);

                SSL_CTX_set_verify(ctx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);
                SSL_CTX_set_verify(clictx, SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE, OnVerify);

                // Needs the flag as it ignores a plain /rehash
                OnRehash(NULL,"ssl");
                Implementation eventlist[] = { I_OnRawSocketConnect, I_OnRawSocketAccept, I_OnRawSocketClose, I_OnRawSocketRead, I_OnRawSocketWrite, I_OnCleanup, I_On005Numeric,
                        I_OnBufferFlushed, I_OnRequest, I_OnSyncUserMetaData, I_OnDecodeMetaData, I_OnUnloadModule, I_OnRehash, I_OnWhois, I_OnPostConnect, I_OnHookUserIO };
                ServerInstance->Modules->Attach(eventlist, this, 16);
        }

        virtual void OnHookUserIO(User* user, const std::string &targetip)
        {
                if (!user->io && isin(targetip,user->GetPort(), listenports))
                {
                        /* Hook the user with our module */
                        user->io = this;
                }
        }

        virtual void OnRehash(User* user, const std::string &param)
        {
                ConfigReader Conf(ServerInstance);

                listenports.clear();
                clientactive = 0;
                sslports.clear();

                for(int index = 0; index < Conf.Enumerate("bind"); index++)
                {
                        // For each <bind> tag
                        std::string x = Conf.ReadValue("bind", "type", index);
                        if(((x.empty()) || (x == "clients")) && (Conf.ReadValue("bind", "ssl", index) == "openssl"))
                        {
                                // Get the port we're meant to be listening on with SSL
                                std::string port = Conf.ReadValue("bind", "port", index);
                                std::string addr = Conf.ReadValue("bind", "address", index);

                                irc::portparser portrange(port, false);
                                long portno = -1;
                                while ((portno = portrange.GetToken()))
                                {
                                        clientactive++;
                                        try
                                        {
                                                listenports.push_back(addr + ":" + ConvToStr(portno));

                                                for (size_t i = 0; i < ServerInstance->Config->ports.size(); i++)
                                                        if ((ServerInstance->Config->ports[i]->GetPort() == portno) && (ServerInstance->Config->ports[i]->GetIP() == addr))
                                                                ServerInstance->Config->ports[i]->SetDescription("ssl");
                                                ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %ld", portno);

                                                sslports.append((addr.empty() ? "*" : addr)).append(":").append(ConvToStr(portno)).append(";");
                                        }
                                        catch (ModuleException &e)
                                        {
                                                ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_gnutls.so: FAILED to enable SSL on port %ld: %s. Maybe it's already hooked by the same port on a different IP, or you have an other SSL or similar module loaded?", portno, e.GetReason());
                                        }
                                }
                        }
                }

                if (!sslports.empty())
                        sslports.erase(sslports.end() - 1);

                if (param != "ssl")
                {
                        return;
                }

                std::string confdir(ServerInstance->ConfigFileName);
                // +1 so we the path ends with a /
                confdir = confdir.substr(0, confdir.find_last_of('/') + 1);

                cafile   = Conf.ReadValue("openssl", "cafile", 0);
                certfile = Conf.ReadValue("openssl", "certfile", 0);
                keyfile  = Conf.ReadValue("openssl", "keyfile", 0);
                dhfile   = Conf.ReadValue("openssl", "dhfile", 0);

                // Set all the default values needed.
                if (cafile.empty())
                        cafile = "ca.pem";

                if (certfile.empty())
                        certfile = "cert.pem";

                if (keyfile.empty())
                        keyfile = "key.pem";

                if (dhfile.empty())
                        dhfile = "dhparams.pem";

                // Prepend relative paths with the path to the config directory.
                if ((cafile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(cafile)))
                        cafile = confdir + cafile;

                if ((certfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(certfile)))
                        certfile = confdir + certfile;

                if ((keyfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(keyfile)))
                        keyfile = confdir + keyfile;

                if ((dhfile[0] != '/') && (!ServerInstance->Config->StartsWithWindowsDriveLetter(dhfile)))
                        dhfile = confdir + dhfile;

                /* Load our keys and certificates
                 * NOTE: OpenSSL's error logging API sucks, don't blame us for this clusterfuck.
                 */
                if ((!SSL_CTX_use_certificate_chain_file(ctx, certfile.c_str())) || (!SSL_CTX_use_certificate_chain_file(clictx, certfile.c_str())))
                {
                        ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read certificate file %s. %s", certfile.c_str(), strerror(errno));
                        ERR_print_errors_cb(error_callback, this);
                }

                if (((!SSL_CTX_use_PrivateKey_file(ctx, keyfile.c_str(), SSL_FILETYPE_PEM))) || (!SSL_CTX_use_PrivateKey_file(clictx, keyfile.c_str(), SSL_FILETYPE_PEM)))
                {
                        ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read key file %s. %s", keyfile.c_str(), strerror(errno));
                        ERR_print_errors_cb(error_callback, this);
                }

                /* Load the CAs we trust*/
                if (((!SSL_CTX_load_verify_locations(ctx, cafile.c_str(), 0))) || (!SSL_CTX_load_verify_locations(clictx, cafile.c_str(), 0)))
                {
                        ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Can't read CA list from %s. %s", cafile.c_str(), strerror(errno));
                        ERR_print_errors_cb(error_callback, this);
                }

                FILE* dhpfile = fopen(dhfile.c_str(), "r");
                DH* ret;

                if (dhpfile == NULL)
                {
                        ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so Couldn't open DH file %s: %s", dhfile.c_str(), strerror(errno));
                        throw ModuleException("Couldn't open DH file " + dhfile + ": " + strerror(errno));
                }
                else
                {
                        ret = PEM_read_DHparams(dhpfile, NULL, NULL, NULL);
                        if ((SSL_CTX_set_tmp_dh(ctx, ret) < 0) || (SSL_CTX_set_tmp_dh(clictx, ret) < 0))
                        {
                                ServerInstance->Logs->Log("m_ssl_openssl",DEFAULT, "m_ssl_openssl.so: Couldn't set DH parameters %s. SSL errors follow:", dhfile.c_str());
                                ERR_print_errors_cb(error_callback, this);
                        }
                }

                fclose(dhpfile);
        }

        virtual void On005Numeric(std::string &output)
        {
                output.append(" SSL=" + sslports);
        }

        virtual ~ModuleSSLOpenSSL()
        {
                SSL_CTX_free(ctx);
                SSL_CTX_free(clictx);
                ServerInstance->Modules->UnpublishInterface("BufferedSocketHook", this);
                delete[] sessions;
        }

        virtual void OnCleanup(int target_type, void* item)
        {
                if (target_type == TYPE_USER)
                {
                        User* user = (User*)item;

                        if (user->io == 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.
                                ServerInstance->Users->QuitUser(user, "SSL module unloading");
                                user->io = NULL;
                        }
                        if (user->GetExt("ssl_cert", dummy))
                        {
                                ssl_cert* tofree;
                                user->GetExt("ssl_cert", tofree);
                                delete tofree;
                                user->Shrink("ssl_cert");
                        }
                }
        }

        virtual void OnUnloadModule(Module* mod, const std::string &name)
        {
                if (mod == this)
                {
                        for(unsigned int i = 0; i < listenports.size(); i++)
                        {
                                for (size_t j = 0; j < ServerInstance->Config->ports.size(); j++)
                                        if (listenports[i] == (ServerInstance->Config->ports[j]->GetIP()+":"+ConvToStr(ServerInstance->Config->ports[j]->GetPort())))
                                                ServerInstance->Config->ports[j]->SetDescription("plaintext");
                        }
                }
        }

        virtual Version GetVersion()
        {
                return Version("$Id: m_ssl_openssl.cpp 10290 2008-08-25 20:35:36Z w00t $", VF_VENDOR, API_VERSION);
        }


        virtual const char* OnRequest(Request* request)
        {
                ISHRequest* ISR = (ISHRequest*)request;
                if (strcmp("IS_NAME", request->GetId()) == 0)
                {
                        return "openssl";
                }
                else if (strcmp("IS_HOOK", request->GetId()) == 0)
                {
                        const char* ret = "OK";
                        try
                        {
                                ret = ServerInstance->Config->AddIOHook((Module*)this, (BufferedSocket*)ISR->Sock) ? "OK" : NULL;
                        }
                        catch (ModuleException &e)
                        {
                                return NULL;
                        }

                        return ret;
                }
                else if (strcmp("IS_UNHOOK", request->GetId()) == 0)
                {
                        return ServerInstance->Config->DelIOHook((BufferedSocket*)ISR->Sock) ? "OK" : NULL;
                }
                else if (strcmp("IS_HSDONE", request->GetId()) == 0)
                {
                        if (ISR->Sock->GetFd() < 0)
                                return "OK";

                        issl_session* session = &sessions[ISR->Sock->GetFd()];
                        return (session->status == ISSL_HANDSHAKING) ? NULL : "OK";
                }
                else if (strcmp("IS_ATTACH", request->GetId()) == 0)
                {
                        issl_session* session = &sessions[ISR->Sock->GetFd()];
                        if (session->sess)
                        {
                                VerifyCertificate(session, (BufferedSocket*)ISR->Sock);
                                return "OK";
                        }
                }
                return NULL;
        }


        virtual void OnRawSocketAccept(int fd, const std::string &ip, int localport)
        {
                /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
                if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
                        return;

                issl_session* session = &sessions[fd];

                session->fd = fd;
                session->inbuf = new char[inbufsize];
                session->inbufoffset = 0;
                session->sess = SSL_new(ctx);
                session->status = ISSL_NONE;
                session->outbound = false;

                if (session->sess == NULL)
                        return;

                if (SSL_set_fd(session->sess, fd) == 0)
                {
                        ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
                        return;
                }

                Handshake(session);
        }

        virtual void OnRawSocketConnect(int fd)
        {
                /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
                if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() -1))
                        return;

                issl_session* session = &sessions[fd];

                session->fd = fd;
                session->inbuf = new char[inbufsize];
                session->inbufoffset = 0;
                session->sess = SSL_new(clictx);
                session->status = ISSL_NONE;
                session->outbound = true;

                if (session->sess == NULL)
                        return;

                if (SSL_set_fd(session->sess, fd) == 0)
                {
                        ServerInstance->Logs->Log("m_ssl_openssl",DEBUG,"BUG: Can't set fd with SSL_set_fd: %d", fd);
                        return;
                }

                Handshake(session);
        }

        virtual void OnRawSocketClose(int fd)
        {
                /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
                if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
                        return;

                CloseSession(&sessions[fd]);

                EventHandler* user = ServerInstance->SE->GetRef(fd);

                if ((user) && (user->GetExt("ssl_cert", dummy)))
                {
                        ssl_cert* tofree;
                        user->GetExt("ssl_cert", tofree);
                        delete tofree;
                        user->Shrink("ssl_cert");
                }
        }

        virtual int OnRawSocketRead(int fd, char* buffer, unsigned int count, int &readresult)
        {
                /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
                if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
                        return 0;

                issl_session* session = &sessions[fd];

                if (!session->sess)
                {
                        readresult = 0;
                        CloseSession(session);
                        return 1;
                }

                if (session->status == ISSL_HANDSHAKING)
                {
                        if (session->rstat == ISSL_READ || session->wstat == ISSL_READ)
                        {
                                // The handshake isn't finished and it wants to read, try to finish it.
                                if (!Handshake(session))
                                {
                                        // Couldn't resume handshake.
                                        return -1;
                                }
                        }
                        else
                        {
                                errno = EAGAIN;
                                return -1;
                        }
                }

                // If we resumed the handshake then session->status will be ISSL_OPEN

                if (session->status == ISSL_OPEN)
                {
                        if (session->wstat == ISSL_READ)
                        {
                                if(DoWrite(session) == 0)
                                        return 0;
                        }

                        if (session->rstat == ISSL_READ)
                        {
                                int ret = DoRead(session);

                                if (ret > 0)
                                {
                                        if (count <= session->inbufoffset)
                                        {
                                                memcpy(buffer, session->inbuf, count);
                                                // Move the stuff left in inbuf to the beginning of it
                                                memmove(session->inbuf, session->inbuf + count, (session->inbufoffset - count));
                                                // Now we need to set session->inbufoffset to the amount of data still waiting to be handed to insp.
                                                session->inbufoffset -= count;
                                                // Insp uses readresult as the count of how much data there is in buffer, so:
                                                readresult = count;
                                        }
                                        else
                                        {
                                                // There's not as much in the inbuf as there is space in the buffer, so just copy the whole thing.
                                                memcpy(buffer, session->inbuf, session->inbufoffset);

                                                readresult = session->inbufoffset;
                                                // Zero the offset, as there's nothing there..
                                                session->inbufoffset = 0;
                                        }
                                        return 1;
                                }
                                return ret;
                        }
                }

                return -1;
        }

        virtual int OnRawSocketWrite(int fd, const char* buffer, int count)
        {
                /* Are there any possibilities of an out of range fd? Hope not, but lets be paranoid */
                if ((fd < 0) || (fd > ServerInstance->SE->GetMaxFds() - 1))
                        return 0;

                issl_session* session = &sessions[fd];

                if (!session->sess)
                {
                        CloseSession(session);
                        return -1;
                }

                session->outbuf.append(buffer, count);
                MakePollWrite(session);

                if (session->status == ISSL_HANDSHAKING)
                {
                        // The handshake isn't finished, try to finish it.
                        if (session->rstat == ISSL_WRITE || session->wstat == ISSL_WRITE)
                        {
                                Handshake(session);
                        }
                }

                if (session->status == ISSL_OPEN)
                {
                        if (session->rstat == ISSL_WRITE)
                        {
                                DoRead(session);
                        }

                        if (session->wstat == ISSL_WRITE)
                        {
                                return DoWrite(session);
                        }
                }

                return 1;
        }

        int DoWrite(issl_session* session)
        {
                if (!session->outbuf.size())
                        return -1;

                int ret = SSL_write(session->sess, session->outbuf.data(), session->outbuf.size());

                if (ret == 0)
                {
                        CloseSession(session);
                        return 0;
                }
                else if (ret < 0)
                {
                        int err = SSL_get_error(session->sess, ret);

                        if (err == SSL_ERROR_WANT_WRITE)
                        {
                                session->wstat = ISSL_WRITE;
                                return -1;
                        }
                        else if (err == SSL_ERROR_WANT_READ)
                        {
                                session->wstat = ISSL_READ;
                                return -1;
                        }
                        else
                        {
                                CloseSession(session);
                                return 0;
                        }
                }
                else
                {
                        session->outbuf = session->outbuf.substr(ret);
                        return ret;
                }
        }

        int DoRead(issl_session* session)
        {
                // Is this right? Not sure if the unencrypted data is garaunteed to be the same length.
                // Read into the inbuffer, offset from the beginning by the amount of data we have that insp hasn't taken yet.

                int ret = SSL_read(session->sess, session->inbuf + session->inbufoffset, inbufsize - session->inbufoffset);

                if (ret == 0)
                {
                        // Client closed connection.
                        CloseSession(session);
                        return 0;
                }
                else if (ret < 0)
                {
                        int err = SSL_get_error(session->sess, ret);

                        if (err == SSL_ERROR_WANT_READ)
                        {
                                session->rstat = ISSL_READ;
                                return -1;
                        }
                        else if (err == SSL_ERROR_WANT_WRITE)
                        {
                                session->rstat = ISSL_WRITE;
                                MakePollWrite(session);
                                return -1;
                        }
                        else
                        {
                                CloseSession(session);
                                return 0;
                        }
                }
                else
                {
                        // Read successfully 'ret' bytes into inbuf + inbufoffset
                        // There are 'ret' + 'inbufoffset' bytes of data in 'inbuf'
                        // 'buffer' is 'count' long

                        session->inbufoffset += ret;

                        return ret;
                }
        }

        // :kenny.chatspike.net 320 Om Epy|AFK :is a Secure Connection
        virtual void OnWhois(User* source, User* dest)
        {
                if (!clientactive)
                        return;

                // Bugfix, only send this numeric for *our* SSL users
                if (dest->GetExt("ssl", dummy) || ((IS_LOCAL(dest) && dest->io == this)))
                {
                        ServerInstance->SendWhoisLine(source, dest, 320, "%s %s :is using a secure connection", source->nick.c_str(), dest->nick.c_str());
                }
        }

        virtual void OnSyncUserMetaData(User* user, Module* proto, void* opaque, const std::string &extname, bool displayable)
        {
                // check if the linking module wants to know about OUR metadata
                if (extname == "ssl")
                {
                        // check if this user has an swhois field to send
                        if(user->GetExt(extname, dummy))
                        {
                                // call this function in the linking module, let it format the data how it
                                // sees fit, and send it on its way. We dont need or want to know how.
                                proto->ProtoSendMetaData(opaque, TYPE_USER, user, extname, displayable ? "Enabled" : "ON");
                        }
                }
        }

        virtual void OnDecodeMetaData(int target_type, void* target, const std::string &extname, const std::string &extdata)
        {
                // check if its our metadata key, and its associated with a user
                if ((target_type == TYPE_USER) && (extname == "ssl"))
                {
                        User* dest = (User*)target;
                        // if they dont already have an ssl flag, accept the remote server's
                        if (!dest->GetExt(extname, dummy))
                        {
                                dest->Extend(extname, "ON");
                        }
                }
        }

        bool Handshake(issl_session* session)
        {
                int ret;

                if (session->outbound)
                        ret = SSL_connect(session->sess);
                else
                        ret = SSL_accept(session->sess);

                if (ret < 0)
                {
                        int err = SSL_get_error(session->sess, ret);

                        if (err == SSL_ERROR_WANT_READ)
                        {
                                session->rstat = ISSL_READ;
                                session->status = ISSL_HANDSHAKING;
                                return true;
                        }
                        else if (err == SSL_ERROR_WANT_WRITE)
                        {
                                session->wstat = ISSL_WRITE;
                                session->status = ISSL_HANDSHAKING;
                                MakePollWrite(session);
                                return true;
                        }
                        else
                        {
                                CloseSession(session);
                        }

                        return false;
                }
                else if (ret > 0)
                {
                        // Handshake complete.
                        // This will do for setting the ssl flag...it could be done earlier if it's needed. But this seems neater.
                        User* u = ServerInstance->FindDescriptor(session->fd);
                        if (u)
                        {
                                if (!u->GetExt("ssl", dummy))
                                        u->Extend("ssl", "ON");
                        }

                        session->status = ISSL_OPEN;

                        MakePollWrite(session);

                        return true;
                }
                else if (ret == 0)
                {
                        CloseSession(session);
                        return true;
                }

                return true;
        }

        virtual void OnPostConnect(User* user)
        {
                // This occurs AFTER OnUserConnect so we can be sure the
                // protocol module has propagated the NICK message.
                if ((user->GetExt("ssl", dummy)) && (IS_LOCAL(user)))
                {
                        // Tell whatever protocol module we're using that we need to inform other servers of this metadata NOW.
                        ServerInstance->PI->SendMetaData(user, TYPE_USER, "SSL", "on");

                        VerifyCertificate(&sessions[user->GetFd()], user);
                        if (sessions[user->GetFd()].sess)
                                user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), SSL_get_cipher(sessions[user->GetFd()].sess));
                }
        }

        void MakePollWrite(issl_session* session)
        {
                //OnRawSocketWrite(session->fd, NULL, 0);
                EventHandler* eh = ServerInstance->FindDescriptor(session->fd);
                if (eh)
                {
                        ServerInstance->SE->WantWrite(eh);
                }
        }

        virtual void OnBufferFlushed(User* user)
        {
                if (user->GetExt("ssl"))
                {
                        issl_session* session = &sessions[user->GetFd()];
                        if (session && session->outbuf.size())
                                OnRawSocketWrite(user->GetFd(), NULL, 0);
                }
        }

        void CloseSession(issl_session* session)
        {
                if (session->sess)
                {
                        SSL_shutdown(session->sess);
                        SSL_free(session->sess);
                }

                if (session->inbuf)
                {
                        delete[] session->inbuf;
                }

                session->outbuf.clear();
                session->inbuf = NULL;
                session->sess = NULL;
                session->status = ISSL_NONE;
        }

        void VerifyCertificate(issl_session* session, Extensible* user)
        {
                if (!session->sess || !user)
                        return;

                X509* cert;
                ssl_cert* certinfo = new ssl_cert;
                unsigned int n;
                unsigned char md[EVP_MAX_MD_SIZE];
                const EVP_MD *digest = EVP_md5();

                user->Extend("ssl_cert",certinfo);

                cert = SSL_get_peer_certificate((SSL*)session->sess);

                if (!cert)
                {
                        certinfo->data.insert(std::make_pair("error","Could not get peer certificate: "+std::string(get_error())));
                        return;
                }

                certinfo->data.insert(std::make_pair("invalid", SSL_get_verify_result(session->sess) != X509_V_OK ? ConvToStr(1) : ConvToStr(0)));

                if (SelfSigned)
                {
                        certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(0)));
                        certinfo->data.insert(std::make_pair("trusted",ConvToStr(1)));
                }
                else
                {
                        certinfo->data.insert(std::make_pair("unknownsigner",ConvToStr(1)));
                        certinfo->data.insert(std::make_pair("trusted",ConvToStr(0)));
                }

                certinfo->data.insert(std::make_pair("dn",std::string(X509_NAME_oneline(X509_get_subject_name(cert),0,0))));
                certinfo->data.insert(std::make_pair("issuer",std::string(X509_NAME_oneline(X509_get_issuer_name(cert),0,0))));

                if (!X509_digest(cert, digest, md, &n))
                {
                        certinfo->data.insert(std::make_pair("error","Out of memory generating fingerprint"));
                }
                else
                {
                        certinfo->data.insert(std::make_pair("fingerprint",irc::hex(md, n)));
                }

                if ((ASN1_UTCTIME_cmp_time_t(X509_get_notAfter(cert), time(NULL)) == -1) || (ASN1_UTCTIME_cmp_time_t(X509_get_notBefore(cert), time(NULL)) == 0))
                {
                        certinfo->data.insert(std::make_pair("error","Not activated, or expired certificate"));
                }

                X509_free(cert);
        }

        void Prioritize()
        {
                Module* server = ServerInstance->Modules->Find("m_spanningtree.so");
                ServerInstance->Modules->SetPriority(this,