/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2009-2010 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2008 John Brooks <john.brooks@dereferenced.net>
* Copyright (C) 2006-2008 Craig Edwards <craigedwards@brainbox.cc>
* Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
* Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
*
* This file is part of InspIRCd. InspIRCd is free software: you can
* redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "inspircd.h"
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include <gcrypt.h>
#include "ssl.h"
#include "m_cap.h"
/* $ModDesc: Provides SSL support for clients */
/* $CompileFlags: pkgconfincludes("gnutls","/gnutls/gnutls.h","") */
/* $LinkerFlags: rpath("pkg-config --libs gnutls") pkgconflibs("gnutls","/libgnutls.so","-lgnutls") -lgcrypt */
enum issl_status { ISSL_NONE, ISSL_HANDSHAKING_READ, ISSL_HANDSHAKING_WRITE, ISSL_HANDSHAKEN, ISSL_CLOSING, ISSL_CLOSED };
static std::vector<gnutls_x509_crt_t> x509_certs;
static gnutls_x509_privkey_t x509_key;
static int cert_callback (gnutls_session_t session, const gnutls_datum_t * req_ca_rdn, int nreqs,
const gnutls_pk_algorithm_t * sign_algos, int sign_algos_length, gnutls_retr_st * st) {
st->type = GNUTLS_CRT_X509;
st->ncerts = x509_certs.size();
st->cert.x509 = &x509_certs[0];
st->key.x509 = x509_key;
st->deinit_all = 0;
return 0;
}
static ssize_t gnutls_pull_wrapper(gnutls_transport_ptr_t user_wrap, void* buffer, size_t size)
{
StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
if (user->GetEventMask() & FD_READ_WILL_BLOCK)
{
errno = EAGAIN;
return -1;
}
int rv = ServerInstance->SE->Recv(user, reinterpret_cast<char *>(buffer), size, 0);
if (rv < (int)size)
ServerInstance->SE->ChangeEventMask(user, FD_READ_WILL_BLOCK);
return rv;
}
static ssize_t gnutls_push_wrapper(gnutls_transport_ptr_t user_wrap, const void* buffer, size_t size)
{
StreamSocket* user = reinterpret_cast<StreamSocket*>(user_wrap);
if (user->GetEventMask() & FD_WRITE_WILL_BLOCK)
{
errno = EAGAIN;
return -1;
}
int rv = ServerInstance->SE->Send(user, reinterpret_cast<const char *>(buffer), size, 0);
if (rv < (int)size)
ServerInstance->SE->ChangeEventMask(user, FD_WRITE_WILL_BLOCK);
return rv;
}
class RandGen : public HandlerBase2<void, char*, size_t>
{
public:
RandGen() {}
void Call(char* buffer, size_t len)
{
gcry_randomize(buffer, len, GCRY_STRONG_RANDOM);
}
};
/** Represents an SSL user's extra data
*/
class issl_session
{
public:
gnutls_session_t sess;
issl_status status;
reference<ssl_cert> cert;
issl_session() : sess(NULL) {}
};
class CommandStartTLS : public SplitCommand
{
public:
bool enabled;
CommandStartTLS (Module* mod) : SplitCommand(mod, "STARTTLS")
{
enabled = true;
works_before_reg = true;
}
CmdResult HandleLocal(const std::vector<std::string> ¶meters, LocalUser *user)
{
if (!enabled)
{
user->WriteNumeric(691, "%s :STARTTLS is not enabled", user->nick.c_str());
return CMD_FAILURE;
}
if (user->registered == REG_ALL)
{
user->WriteNumeric(691, "%s :STARTTLS is not permitted after client registration is complete", user->nick.c_str());
}
else
{
if (!user->eh.GetIOHook())
{
user->WriteNumeric(670, "%s :STARTTLS successful, go ahead with TLS handshake", user->nick.c_str());
/* We need to flush the write buffer prior to adding the IOHook,
* otherwise we'll be sending this line inside the SSL session - which
* won't start its handshake until the client gets this line. Currently,
* we assume the write will not block here; this is usually safe, as
* STARTTLS is sent very early on in the registration phase, where the
* user hasn't built up much sendq. Handling a blocked write here would
* be very annoying.
*/
user->eh.DoWrite();
user->eh.AddIOHook(creator);
creator->OnStreamSocketAccept(&user->eh, NULL, NULL);
}
else
user->WriteNumeric(691, "%s :STARTTLS failure", user->nick.c_str());
}
return CMD_FAILURE;
}
};
class ModuleSSLGnuTLS : public Module
{
issl_session* sessions;
gnutls_certificate_credentials x509_cred;
gnutls_dh_params dh_params;
gnutls_digest_algorithm_t hash;
std::string sslports;
int dh_bits;
bool cred_alloc;
bool dh_alloc;
RandGen randhandler;
CommandStartTLS starttls;
GenericCap capHandler;
ServiceProvider iohook;
public:
ModuleSSLGnuTLS()
: starttls(this), capHandler(this, "tls"), iohook(this, "ssl/gnutls", SERVICE_IOHOOK)
{
sessions = new issl_session[ServerInstance->SE->GetMaxFds()];
gnutls_global_init(); // This must be called once in the program
gnutls_x509_privkey_init(&x509_key);
cred_alloc = false;
dh_alloc = false;
}
void init()
{
// Needs the flag as it ignores a plain /rehash
OnModuleRehash(NULL,"ssl");
ServerInstance->GenRandom = &randhandler;
// Void return, guess we assume success
gnutls_certificate_set_dh_params(x509_cred, dh_params);
Implementation eventlist[] = { I_On005Numeric, I_OnRehash, I_OnModuleRehash, I_OnUserConnect,
I_OnEvent, I_OnHookIO };
ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
ServerInstance->Modules->AddService(iohook);
ServerInstance->AddCommand(&starttls);
}
void OnRehash(User* user)
{
sslports.clear();
ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
starttls.enabled = Conf->getBool("starttls", true);
if (Conf->getBool("showports", true))
{
for (size_t i = 0; i < ServerInstance->ports.size(); i++)
{
ListenSocket* port = ServerInstance->ports[i];
if (port->bind_tag->getString("ssl") != "gnutls")
continue;
const std::string& portid = port->bind_desc;
ServerInstance->Logs->Log("m_ssl_gnutls", DEFAULT, "m_ssl_gnutls.so: Enabling SSL for port %s", portid.c_str());
if (port->bind_tag->getString("type", "clients") == "clients" && port->bind_addr != "127.0.0.1")
sslports.append(portid).append(";");
}
if (!sslports.empty())
sslports.erase(sslports.end() - 1);
}
}
void OnModuleRehash(User* user, const std::string ¶m)
{
if(param != "ssl")
return;
std::string keyfile;
std::string certfile;
std::string cafile;
std::string crlfile;
OnRehash(user);
ConfigTag* Conf = ServerInstance->Config->ConfValue("gnutls");
cafile = Conf->getString("cafile", "conf/ca.pem");
crlfile = Conf->getString("crlfile", "conf/crl.pem");
certfile = Conf->getString("certfile", "conf/cert.pem");
keyfile = Conf->getString("keyfile", "conf/key.pem");
dh_bits = Conf->getInt("dhbits");
std::string hashname = Conf->getString("hash", "md5");
if((dh_bits != 768) && (dh_bits != 1024) && (dh_bits != 2048) && (dh_bits != 3072) && (dh_bits != 4096))
dh_bits = 1024;
if (hashname == "md5")
hash = GNUTLS_DIG_MD5;
else if (hashname == "sha1")
hash = GNUTLS_DIG_SHA1;
else
throw ModuleException("Unknown hash type " + hashname);
int ret;
if (dh_alloc)
{
gnutls_dh_params_deinit(dh_params);
dh_alloc = false;
}
if (cred_alloc)
{
// Deallocate the old credentials
gnutls_certificate_free_credentials(x509_cred);
for(unsigned int i=0; i < x509_certs.size(); i++)
gnutls_x509_crt_deinit(x509_certs[i]);
x509_certs.clear();
}
ret = gnutls_certificate_allocate_credentials(&x509_cred);
cred_alloc = (ret >= 0);
if (!cred_alloc)
ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to allocate certificate credentials: %s", gnutls_strerror(ret));
if((ret =gnutls_certificate_set_x509_trust_file(x509_cred, cafile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 trust file '%s': %s", cafile.c_str(), gnutls_strerror(ret));
if((ret = gnutls_certificate_set_x509_crl_file (x509_cred, crlfile.c_str(), GNUTLS_X509_FMT_PEM)) < 0)
ServerInstance->Logs->Log("m_ssl_gnutls",DEBUG, "m_ssl_gnutls.so: Failed to set X.509 CRL file '%s': %s", crlfile.c_str(), gnutls_strerror(ret));
FileReader reader;
reader.LoadFile(certfile);
std::string cert_string = reader.Contents();
gnutls_datum_t cert_datum = { (unsigned char*)cert_string.data(), cert_string.length() };
reader.LoadFile(keyfile);
std::string key_string = reader.Contents();
gnutls_datum_t key_datum = { (unsigned char*)key_string.data(), key_string.length() };
// If this fails, no SSL port will work. At all. So, do the smart thing - throw a ModuleException
unsigned int certcount = Conf->getInt("certcount", 3);
x509_certs.resize(certcount);
ret = gnutls_x509_crt_list_import(&x509_certs[0], &certcount, &cert_datum, GNUTLS_X509_FMT_PEM, GNUTLS_X509_CRT_LIST_IMPORT_FAIL_IF_EXCEED);
if (ret < 0)
throw ModuleException("Unable to load GnuTLS server certificate (" + certfile + "): " + std::string(gnutls_strerror(ret)));
x509_certs.resize(certcount);
if((ret = gnutls_x509_privkey_import(x509_key, &key_datum, GNUTLS_X509_FMT_PEM)) < 0)
throw ModuleException("Unable to load GnuTLS server private key (" + keyfile + "): " + std::string(gnutls_strerror(ret)));
if((ret = gnutls_certificate_set_x509_key(x509_cred, &x509_certs[0], certcount, x509_key)) < 0)
throw ModuleException("Unable to set GnuTLS cert/key pair: " + std::string(gnutls_strerror(ret)));
gnutls_certificate_client_set_retrieve_function (x509_cred, cert_callback);
ret = gnutls_dh_params_init(&dh_params);
dh_alloc = (ret >= 0);
if (!dh_alloc)
ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to initialise DH parameters: %s", gnutls_strerror(ret));
// This may be on a large (once a day or week) timer eventually.
GenerateDHParams();
}
void GenerateDHParams()
{
// Generate Diffie Hellman parameters - for use with DHE
// kx algorithms. These should be discarded and regenerated
// once a day, once a week or once a month. Depending on the
// security requirements.
if (!dh_alloc)
return;
int ret;
if((ret = gnutls_dh_params_generate2(dh_params, dh_bits)) < 0)
ServerInstance->Logs->Log("m_ssl_gnutls",DEFAULT, "m_ssl_gnutls.so: Failed to generate DH parameters (%d bits): %s", dh_bits, gnutls_strerror(ret));
}
~ModuleSSLGnuTLS()
{
for(unsigned int i=0; i < x509_certs.size(); i++)
gnutls_x509_crt_deinit(x509_certs[i]);
gnutls_x509_privkey_deinit(x509_key);
if (dh_alloc)
gnutls_dh_params_deinit(dh_params);
if (cred_alloc)
gnutls_certificate_free_credentials(x509_cred);
gnutls_global_deinit();
delete[] sessions;
ServerInstance->GenRandom = &ServerInstance->HandleGenRandom;
}
void OnCleanup(int target_type, void* item)
{
if(target_type == TYPE_USER)
{
LocalUser* user = IS_LOCAL(static_cast<User*>(item));
if (user && user->eh.GetIOHook() == 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");
}
}
}
Version GetVersion()
{
return Version("Provides SSL support for clients", VF_VENDOR);
}
void On005Numeric(std::string &output)
{
if (!sslports.empty())
output.append(" SSL=" + sslports);
if (starttls.enabled)
output.append(" STARTTLS");
}
void OnHookIO(StreamSocket* user, ListenSocket* lsb)
{
if (!user->GetIOHook() && lsb->bind_tag->getString("ssl") == "gnutls")
{
/* Hook the user with our module */
user->AddIOHook(this);
}
}
void OnRequest(Request& request)
{
if (strcmp("GET_SSL_CERT", request.id) == 0)
{
SocketCertificateRequest& req = static_cast<SocketCertificateRequest&>(request);
int fd = req.sock->GetFd();
issl_session* session = &sessions[fd];
req.cert = session->cert;
}
}
void OnStreamSocketAccept(StreamSocket* user, irc::sockets::sockaddrs* client, irc::sockets::sockaddrs* server)
{
int fd = user->GetFd();
issl_session* session = &sessions[fd];
/* For STARTTLS: Don't try and init a session on a socket that already has a session */
if (session->sess)
return;
gnutls_init(&session->sess, GNUTLS_SERVER);
gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
gnutls_dh_set_prime_bits(session->sess, dh_bits);
gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
gnutls_certificate_server_set_request(session->sess, GNUTLS_CERT_REQUEST); // Request client certificate if any.
Handshake(session, user);
}
void OnStreamSocketConnect(StreamSocket* user)
{
issl_session* session = &sessions[user->GetFd()];
gnutls_init(&session->sess, GNUTLS_CLIENT);
gnutls_set_default_priority(session->sess); // Avoid calling all the priority functions, defaults are adequate.
gnutls_credentials_set(session->sess, GNUTLS_CRD_CERTIFICATE, x509_cred);
gnutls_dh_set_prime_bits(session->sess, dh_bits);
gnutls_transport_set_ptr(session->sess, reinterpret_cast<gnutls_transport_ptr_t>(user));
gnutls_transport_set_push_function(session->sess, gnutls_push_wrapper);
gnutls_transport_set_pull_function(session->sess, gnutls_pull_wrapper);
Handshake(session, user);
}
void OnStreamSocketClose(StreamSocket* user)
{
CloseSession(&sessions[user->GetFd()]);
}
int OnStreamSocketRead(StreamSocket* user, std::string& recvq)
{
issl_session* session = &sessions[user->GetFd()];
if (!session->sess)
{
CloseSession(session);
user->SetError("No SSL session");
return -1;
}
if (session->status == ISSL_HANDSHAKING_READ || session->status == ISSL_HANDSHAKING_WRITE)
{
// The handshake isn't finished, try to finish it.
if(!Handshake(session, user))
{
if (session->status != ISSL_CLOSING)
return 0;
return -1;
}
}
// If we resumed the handshake then session->status will be ISSL_HANDSHAKEN.
if (session->status == ISSL_HANDSHAKEN)
{
char* buffer = ServerInstance->GetReadBuffer();
size_t bufsiz = ServerInstance->Config->NetBufferSize;
int ret = gnutls_record_recv(session->sess, buffer, bufsiz);
if (ret > 0)
{
recvq.append(buffer, ret);
return 1;
}
else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
{
return 0;
}
else if (ret == 0)
{
user->SetError("SSL Connection closed");
CloseSession(session);
return -1;
}
else
{
user->SetError(gnutls_strerror(ret));
CloseSession(session);
return -1;
}
}
else if (session->status == ISSL_CLOSING)
return -1;
return 0;
}
int OnStreamSocketWrite(StreamSocket* user, std::string& sendq)
{
issl_session* session = &sessions[user->GetFd()];
if (!session->sess)
{
CloseSession(session);
user->SetError("No SSL session");
return -1;
}
if (session->status == ISSL_HANDSHAKING_WRITE || session->status == ISSL_HANDSHAKING_READ)
{
// The handshake isn't finished, try to finish it.
Handshake(session, user);
if (session->status != ISSL_CLOSING)
return 0;
return -1;
}
int ret = 0;
if (session->status == ISSL_HANDSHAKEN)
{
ret = gnutls_record_send(session->sess, sendq.data(), sendq.length());
if (ret == (int)sendq.length())
{
ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_WRITE);
return 1;
}
else if (ret > 0)
{
sendq = sendq.substr(ret);
ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
return 0;
}
else if (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED || ret == 0)
{
ServerInstance->SE->ChangeEventMask(user, FD_WANT_SINGLE_WRITE);
return 0;
}
else // (ret < 0)
{
user->SetError(gnutls_strerror(ret));
CloseSession(session);
return -1;
}
}
return 0;
}
bool Handshake(issl_session* session, StreamSocket* user)
{
int ret = gnutls_handshake(session->sess);
if (ret < 0)
{
if(ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)
{
// Handshake needs resuming later, read() or write() would have blocked.
if(gnutls_record_get_direction(session->sess) == 0)
{
// gnutls_handshake() wants to read() again.
session->status = ISSL_HANDSHAKING_READ;
ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
}
else
{
// gnutls_handshake() wants to write() again.
session->status = ISSL_HANDSHAKING_WRITE;
ServerInstance->SE->ChangeEventMask(user, FD_WANT_NO_READ | FD_WANT_SINGLE_WRITE);
}
}
else
{
user->SetError(std::string("Handshake Failed - ") + gnutls_strerror(ret));
CloseSession(session);
session->status = ISSL_CLOSING;
}
return false;
}
else
{
// Change the seesion state
session->status = ISSL_HANDSHAKEN;
VerifyCertificate(session,user);
// Finish writing, if any left
ServerInstance->SE->ChangeEventMask(user, FD_WANT_POLL_READ | FD_WANT_NO_WRITE | FD_ADD_TRIAL_WRITE);
return true;
}
}
void OnUserConnect(LocalUser* user)
{
if (user->eh.GetIOHook() == this)
{
if (sessions[user->eh.GetFd()].sess)
{
ssl_cert* cert = sessions[user->eh.GetFd()].cert;
std::string cipher = gnutls_kx_get_name(gnutls_kx_get(sessions[user->eh.GetFd()].sess));
cipher.append("-").append(gnutls_cipher_get_name(gnutls_cipher_get(sessions[user->eh.GetFd()].sess))).append("-");
cipher.append(gnutls_mac_get_name(gnutls_mac_get(sessions[user->eh.GetFd()].sess)));
if (cert->fingerprint.empty())
user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\"", user->nick.c_str(), cipher.c_str());
else
user->WriteServ("NOTICE %s :*** You are connected using SSL cipher \"%s\""
" and your SSL fingerprint is %s", user->nick.c_str(), cipher.c_str(), cert->fingerprint.c_str());
}
}
}
void CloseSession(issl_session* session)
{
if (session->sess)
{
gnutls_bye(session->sess, GNUTLS_SHUT_WR);
gnutls_deinit(session->sess);
}
session->sess = NULL;
session->cert = NULL;
session->status = ISSL_NONE;
}
void VerifyCertificate(issl_session* session, StreamSocket* user)
{
if (!session->sess || !user)
return;
unsigned int status;
const gnutls_datum_t* cert_list;
int ret;
unsigned int cert_list_size;
gnutls_x509_crt_t cert;
char name[MAXBUF];
unsigned char digest[MAXBUF];
size_t digest_size = sizeof(digest);
size_t name_size = sizeof(name);
ssl_cert* certinfo = new ssl_cert;
session->cert = certinfo;
/* This verification function uses the trusted CAs in the credentials
* structure. So you must have installed one or more CA certificates.
*/
ret = gnutls_certificate_verify_peers2(session->sess, &status);
if (ret < 0)
{
certinfo->error = std::string(gnutls_strerror(ret));
return;
}
certinfo->invalid = (status & GNUTLS_CERT_INVALID);
certinfo->unknownsigner = (status & GNUTLS_CERT_SIGNER_NOT_FOUND);
certinfo->revoked = (status & GNUTLS_CERT_REVOKED);
certinfo->trusted = !(status & GNUTLS_CERT_SIGNER_NOT_CA);
/* Up to here the process is the same for X.509 certificates and
* OpenPGP keys. From now on X.509 certificates are assumed. This can
* be easily extended to work with openpgp keys as well.
*/
if (gnutls_certificate_type_get(session->sess) != GNUTLS_CRT_X509)
{
certinfo->error = "No X509 keys sent";
return;
}
ret = gnutls_x509_crt_init(&cert);
if (ret < 0)
{
certinfo->error = gnutls_strerror(ret);
return;
}
cert_list_size = 0;
cert_list = gnutls_certificate_get_peers(session->sess, &cert_list_size);
if (cert_list == NULL)
{
certinfo->error = "No certificate was found";
goto info_done_dealloc;
}
/* This is not a real world example, since we only check the first
* certificate in the given chain.
*/
ret = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER);
if (ret < 0)
{
certinfo->error = gnutls_strerror(ret);
goto info_done_dealloc;
}
gnutls_x509_crt_get_dn(cert, name, &name_size);
certinfo->dn = name;
gnutls_x509_crt_get_issuer_dn(cert, name, &name_size);
certinfo->issuer = name;
if ((ret = gnutls_x509_crt_get_fingerprint(cert, hash, digest, &digest_size)) < 0)
{
certinfo->error = gnutls_strerror(ret);
}
else
{
certinfo->fingerprint = irc::hex(digest, digest_size);
}
/* Beware here we do not check for errors.
*/
if ((gnutls_x509_crt_get_expiration_time(cert) < ServerInstance->Time()) || (gnutls_x509_crt_get_activation_time(cert) > ServerInstance->Time()))
{
certinfo->error = "Not activated, or expired certificate";
}
info_done_dealloc:
gnutls_x509_crt_deinit(cert);
}
void OnEvent(Event& ev)
{
if (starttls.enabled)
capHandler.HandleEvent(ev);
}
};
MODULE_INIT(ModuleSSLGnuTLS)
