/* * ngIRCd -- The Next Generation IRC Daemon * Copyright (c) 2005-2008 Florian Westphal */ #include "portab.h" /** * @file * SSL wrapper functions */ #include "imp.h" #include "conf-ssl.h" #ifdef SSL_SUPPORT #include "io.h" #include #include #include #include #include #define CONN_MODULE #include "conn.h" #include "conf.h" #include "conn-func.h" #include "conn-ssl.h" #include "log.h" #include "exp.h" #include "defines.h" extern struct SSLOptions Conf_SSLOptions; #ifdef HAVE_LIBSSL #include #include static SSL_CTX * ssl_ctx; static DH *dh_params; static bool ConnSSL_LoadServerKey_openssl PARAMS(( SSL_CTX *c )); #endif #ifdef HAVE_LIBGNUTLS #include #include #include #include #include #define DH_BITS 2048 #define DH_BITS_MIN 1024 static gnutls_certificate_credentials_t x509_cred; static gnutls_dh_params_t dh_params; static bool ConnSSL_LoadServerKey_gnutls PARAMS(( void )); #endif static bool ConnSSL_Init_SSL PARAMS(( CONNECTION *c )); static int ConnectAccept PARAMS(( CONNECTION *c, bool connect )); static int ConnSSL_HandleError PARAMS(( CONNECTION *c, const int code, const char *fname )); #ifdef HAVE_LIBGNUTLS static char * openreadclose(const char *name, size_t *len) { char *buf = NULL; struct stat s; ssize_t br; int fd = open(name, O_RDONLY); if (fd < 0) { Log(LOG_ERR, "Could not open %s: %s", name, strerror(errno)); return NULL; } if (fstat(fd, &s)) { Log(LOG_ERR, "Could not fstat %s: %s", name, strerror(errno)); goto out; } if (!S_ISREG(s.st_mode)) { Log(LOG_ERR, "%s: Not a regular file", name); goto out; } if (s.st_size <= 0) { Log(LOG_ERR, "%s: invalid file length (size %ld <= 0)", name, (long) s.st_size); goto out; } buf = malloc(s.st_size); if (!buf) { Log(LOG_ERR, "Could not malloc %lu bytes for file %s: %s", s.st_size, name, strerror(errno)); goto out; } br = read(fd, buf, s.st_size); if (br != (ssize_t)s.st_size) { Log(LOG_ERR, "Could not read file %s: read returned %ld, expected %ld: %s", name, (long) br, (long) s.st_size, br == -1 ? strerror(errno):"short read?!"); memset(buf, 0, s.st_size); free(buf); buf = NULL; } else { *len = br; } out: close(fd); return buf; } #endif #ifdef HAVE_LIBSSL static void LogOpenSSLError( const char *msg, const char *msg2 ) { unsigned long err = ERR_get_error(); char * errmsg = err ? ERR_error_string(err, NULL) : "Unable to determine error"; if (!msg) msg = "SSL Error"; if (msg2) Log( LOG_ERR, "%s: %s: %s", msg, msg2, errmsg); else Log( LOG_ERR, "%s: %s", msg, errmsg); } static int pem_passwd_cb(char *buf, int size, int rwflag, void *password) { array *pass = password; int passlen; (void)rwflag; /* rwflag is unused if DEBUG is not set. */ assert(rwflag == 0); /* 0 -> callback used for decryption. * See SSL_CTX_set_default_passwd_cb(3) */ passlen = (int) array_bytes(pass); LogDebug("pem_passwd_cb buf size %d, array size %d", size, passlen); assert(passlen >= 0); if (passlen <= 0) { Log(LOG_ERR, "pem_passwd_cb: password required, but not set"); return 0; } size = passlen > size ? size : passlen; memcpy(buf, (char *)(array_start(pass)), size); return size; } #endif static bool Load_DH_params(void) { #ifdef HAVE_LIBSSL FILE *fp; bool ret = true; if (!Conf_SSLOptions.DHFile) { Log(LOG_NOTICE, "Configuration option \"DHFile\" not set!"); return false; } fp = fopen(Conf_SSLOptions.DHFile, "r"); if (!fp) { Log(LOG_ERR, "%s: %s", Conf_SSLOptions.DHFile, strerror(errno)); return false; } dh_params = PEM_read_DHparams(fp, NULL, NULL, NULL); if (!dh_params) { Log(LOG_ERR, "%s: PEM_read_DHparams failed!", Conf_SSLOptions.DHFile); ret = false; } fclose(fp); return ret; #endif #ifdef HAVE_LIBGNUTLS bool need_dhgenerate = true; int err; gnutls_dh_params_t tmp_dh_params; err = gnutls_dh_params_init(&tmp_dh_params); if (err < 0) { Log(LOG_ERR, "gnutls_dh_params_init: %s", gnutls_strerror(err)); return false; } if (Conf_SSLOptions.DHFile) { gnutls_datum_t dhparms; size_t size; dhparms.data = (unsigned char *) openreadclose(Conf_SSLOptions.DHFile, &size); if (dhparms.data) { dhparms.size = size; err = gnutls_dh_params_import_pkcs3(tmp_dh_params, &dhparms, GNUTLS_X509_FMT_PEM); if (err == 0) need_dhgenerate = false; else Log(LOG_ERR, "gnutls_dh_params_init: %s", gnutls_strerror(err)); memset(dhparms.data, 0, size); free(dhparms.data); } } if (need_dhgenerate) { Log(LOG_WARNING, "DHFile not set, generating %u bit DH parameters. This may take a while ...", DH_BITS); err = gnutls_dh_params_generate2(tmp_dh_params, DH_BITS); if (err < 0) { Log(LOG_ERR, "gnutls_dh_params_generate2: %s", gnutls_strerror(err)); return false; } } dh_params = tmp_dh_params; return true; #endif } void ConnSSL_Free(CONNECTION *c) { #ifdef HAVE_LIBSSL SSL *ssl = c->ssl_state.ssl; if (ssl) { SSL_shutdown(ssl); SSL_free(ssl); c->ssl_state.ssl = NULL; } #endif #ifdef HAVE_LIBGNUTLS gnutls_session_t sess = c->ssl_state.gnutls_session; if (Conn_OPTION_ISSET(c, CONN_SSL)) { gnutls_bye(sess, GNUTLS_SHUT_RDWR); gnutls_deinit(sess); } #endif assert(Conn_OPTION_ISSET(c, CONN_SSL)); /* can't just set bitmask to 0 -- there are other, non-ssl related flags, e.g. CONN_ZIP. */ Conn_OPTION_DEL(c, CONN_SSL_FLAGS_ALL); } bool ConnSSL_InitLibrary( void ) { if (!Conf_SSLInUse()) { LogDebug("SSL not in use, skipping initialization."); return true; } #ifdef HAVE_LIBSSL SSL_CTX *newctx; if (!ssl_ctx) { SSL_library_init(); SSL_load_error_strings(); } if (!RAND_status()) { Log(LOG_ERR, "OpenSSL PRNG not seeded: /dev/urandom missing?"); /* * it is probably best to fail and let the user install EGD or a similar program if no kernel random device is available. * According to OpenSSL RAND_egd(3): "The automatic query of /var/run/egd-pool et al was added in OpenSSL 0.9.7"; * so it makes little sense to deal with PRNGD seeding ourselves. */ array_free(&Conf_SSLOptions.ListenPorts); return false; } newctx = SSL_CTX_new(SSLv23_method()); if (!newctx) { LogOpenSSLError("SSL_CTX_new()", NULL); array_free(&Conf_SSLOptions.ListenPorts); return false; } if (!ConnSSL_LoadServerKey_openssl(newctx)) goto out; SSL_CTX_set_options(newctx, SSL_OP_SINGLE_DH_USE|SSL_OP_NO_SSLv2); SSL_CTX_set_mode(newctx, SSL_MODE_ENABLE_PARTIAL_WRITE); SSL_CTX_free(ssl_ctx); ssl_ctx = newctx; Log(LOG_INFO, "%s initialized.", SSLeay_version(SSLEAY_VERSION)); return true; out: SSL_CTX_free(newctx); array_free(&Conf_SSLOptions.ListenPorts); return false; #endif #ifdef HAVE_LIBGNUTLS int err; static bool initialized; if (initialized) /* TODO: cannot reload gnutls keys: can't simply free x509 context -- it may still be in use */ return false; err = gnutls_global_init(); if (err) { Log(LOG_ERR, "gnutls_global_init(): %s", gnutls_strerror(err)); array_free(&Conf_SSLOptions.ListenPorts); return false; } if (!ConnSSL_LoadServerKey_gnutls()) { array_free(&Conf_SSLOptions.ListenPorts); return false; } Log(LOG_INFO, "gnutls %s initialized.", gnutls_check_version(NULL)); initialized = true; return true; #endif } #ifdef HAVE_LIBGNUTLS static bool ConnSSL_LoadServerKey_gnutls(void) { int err; const char *cert_file; err = gnutls_certificate_allocate_credentials(&x509_cred); if (err < 0) { Log(LOG_ERR, "gnutls_certificate_allocate_credentials: %s", gnutls_strerror(err)); return false; } cert_file = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile; if (!cert_file) { Log(LOG_ERR, "No SSL server key configured!"); return false; } if (array_bytes(&Conf_SSLOptions.KeyFilePassword)) Log(LOG_WARNING, "Ignoring KeyFilePassword: Not supported by GNUTLS."); if (!Load_DH_params()) return false; gnutls_certificate_set_dh_params(x509_cred, dh_params); err = gnutls_certificate_set_x509_key_file(x509_cred, cert_file, Conf_SSLOptions.KeyFile, GNUTLS_X509_FMT_PEM); if (err < 0) { Log(LOG_ERR, "gnutls_certificate_set_x509_key_file (cert %s, key %s): %s", cert_file, Conf_SSLOptions.KeyFile ? Conf_SSLOptions.KeyFile : "(NULL)", gnutls_strerror(err)); return false; } return true; } #endif #ifdef HAVE_LIBSSL static bool ConnSSL_LoadServerKey_openssl(SSL_CTX *ctx) { char *cert_key; assert(ctx); if (!Conf_SSLOptions.KeyFile) { Log(LOG_ERR, "No SSL server key configured!"); return false; } SSL_CTX_set_default_passwd_cb(ctx, pem_passwd_cb); SSL_CTX_set_default_passwd_cb_userdata(ctx, &Conf_SSLOptions.KeyFilePassword); if (SSL_CTX_use_PrivateKey_file(ctx, Conf_SSLOptions.KeyFile, SSL_FILETYPE_PEM) != 1) { array_free_wipe(&Conf_SSLOptions.KeyFilePassword); LogOpenSSLError("SSL_CTX_use_PrivateKey_file", Conf_SSLOptions.KeyFile); return false; } cert_key = Conf_SSLOptions.CertFile ? Conf_SSLOptions.CertFile:Conf_SSLOptions.KeyFile; if (SSL_CTX_use_certificate_chain_file(ctx, cert_key) != 1) { array_free_wipe(&Conf_SSLOptions.KeyFilePassword); LogOpenSSLError("SSL_CTX_use_certificate_file", cert_key); return false; } array_free_wipe(&Conf_SSLOptions.KeyFilePassword); if (!SSL_CTX_check_private_key(ctx)) { LogOpenSSLError("Server Private Key does not match certificate", NULL); return false; } if (Load_DH_params()) { if (SSL_CTX_set_tmp_dh(ctx, dh_params) != 1) LogOpenSSLError("Error setting DH Parameters", Conf_SSLOptions.DHFile); /* don't return false here: the non-DH modes will still work */ DH_free(dh_params); dh_params = NULL; } return true; } #endif static bool ConnSSL_Init_SSL(CONNECTION *c) { int ret; assert(c != NULL); #ifdef HAVE_LIBSSL if (!ssl_ctx) { Log(LOG_ERR, "Cannot init ssl_ctx: OpenSSL initialization failed at startup"); return false; } assert(c->ssl_state.ssl == NULL); c->ssl_state.ssl = SSL_new(ssl_ctx); if (!c->ssl_state.ssl) { LogOpenSSLError("SSL_new()", NULL); return false; } ret = SSL_set_fd(c->ssl_state.ssl, c->sock); if (ret != 1) { LogOpenSSLError("SSL_set_fd()", NULL); ConnSSL_Free(c); return false; } #endif #ifdef HAVE_LIBGNUTLS ret = gnutls_set_default_priority(c->ssl_state.gnutls_session); if (ret < 0) { Log(LOG_ERR, "gnutls_set_default_priority: %s", gnutls_strerror(ret)); ConnSSL_Free(c); return false; } /* * The intermediate (long) cast is here to avoid a warning like: * "cast to pointer from integer of different size" on 64-bit platforms. * There doesn't seem to be an alternate GNUTLS API we could use instead, see e.g. * http://www.mail-archive.com/help-gnutls@gnu.org/msg00286.html */ gnutls_transport_set_ptr(c->ssl_state.gnutls_session, (gnutls_transport_ptr_t) (long) c->sock); ret = gnutls_credentials_set(c->ssl_state.gnutls_session, GNUTLS_CRD_CERTIFICATE, x509_cred); if (ret < 0) { Log(LOG_ERR, "gnutls_credentials_set: %s", gnutls_strerror(ret)); ConnSSL_Free(c); return false; } gnutls_dh_set_prime_bits(c->ssl_state.gnutls_session, DH_BITS_MIN); #endif Conn_OPTION_ADD(c, CONN_SSL); return true; } bool ConnSSL_PrepareConnect(CONNECTION *c, UNUSED CONF_SERVER *s) { bool ret; #ifdef HAVE_LIBGNUTLS int err; err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_CLIENT); if (err) { Log(LOG_ERR, "gnutls_init: %s", gnutls_strerror(err)); return false; } #endif ret = ConnSSL_Init_SSL(c); if (!ret) return false; Conn_OPTION_ADD(c, CONN_SSL_CONNECT); #ifdef HAVE_LIBSSL assert(c->ssl_state.ssl); SSL_set_verify(c->ssl_state.ssl, SSL_VERIFY_NONE, NULL); #endif return true; } /* Check an Handle Error return code after failed calls to ssl/tls functions. OpenSSL: SSL_connect(), SSL_accept(), SSL_do_handshake(), SSL_read(), SSL_peek(), or SSL_write() on ssl. GNUTLS: gnutlsssl_read(), gnutls_write() or gnutls_handshake(). Return: -1 on fatal error, 0 if we can try again later. */ static int ConnSSL_HandleError( CONNECTION *c, const int code, const char *fname ) { #ifdef HAVE_LIBSSL int ret = SSL_ERROR_SYSCALL; unsigned long sslerr; int real_errno = errno; ret = SSL_get_error(c->ssl_state.ssl, code); switch (ret) { case SSL_ERROR_WANT_READ: io_event_del(c->sock, IO_WANTWRITE); Conn_OPTION_ADD(c, CONN_SSL_WANT_READ); return 0; /* try again later */ case SSL_ERROR_WANT_WRITE: io_event_del(c->sock, IO_WANTREAD); Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); /* fall through */ case SSL_ERROR_NONE: return 0; /* try again later */ case SSL_ERROR_ZERO_RETURN: LogDebug("TLS/SSL connection shut down normally"); break; /* SSL_ERROR_WANT_CONNECT, SSL_ERROR_WANT_ACCEPT, SSL_ERROR_WANT_X509_LOOKUP */ case SSL_ERROR_SYSCALL: sslerr = ERR_get_error(); if (sslerr) { Log( LOG_ERR, "%s: %s", fname, ERR_error_string(sslerr, NULL )); } else { switch (code) { /* EOF that violated protocol */ case 0: Log(LOG_ERR, "%s: Client Disconnected", fname ); break; case -1: /* low level socket I/O error, check errno */ Log(LOG_ERR, "%s: %s", fname, strerror(real_errno)); } } break; case SSL_ERROR_SSL: LogOpenSSLError("TLS/SSL Protocol Error", fname); break; default: Log( LOG_ERR, "%s: Unknown error %d!", fname, ret); } ConnSSL_Free(c); return -1; #endif #ifdef HAVE_LIBGNUTLS switch (code) { case GNUTLS_E_AGAIN: case GNUTLS_E_INTERRUPTED: if (gnutls_record_get_direction(c->ssl_state.gnutls_session)) { Conn_OPTION_ADD(c, CONN_SSL_WANT_WRITE); io_event_del(c->sock, IO_WANTREAD); } else { Conn_OPTION_ADD(c, CONN_SSL_WANT_READ); io_event_del(c->sock, IO_WANTWRITE); } break; default: assert(code < 0); if (gnutls_error_is_fatal(code)) { Log(LOG_ERR, "%s: %s", fname, gnutls_strerror(code)); ConnSSL_Free(c); return -1; } } return 0; #endif } static void ConnSSL_LogCertInfo( CONNECTION *c ) { #ifdef HAVE_LIBSSL SSL *ssl = c->ssl_state.ssl; assert(ssl); Log(LOG_INFO, "Connection %d: initialized %s using cipher %s.", c->sock, SSL_get_version(ssl), SSL_get_cipher(ssl)); #endif #ifdef HAVE_LIBGNUTLS gnutls_session_t sess = c->ssl_state.gnutls_session; gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess); Log(LOG_INFO, "Connection %d: initialized %s using cipher %s-%s.", c->sock, gnutls_protocol_get_name(gnutls_protocol_get_version(sess)), gnutls_cipher_get_name(cipher), gnutls_mac_get_name(gnutls_mac_get(sess))); #endif } /* Accept incoming SSL connection. Return Values: 1: SSL Connection established 0: try again -1: SSL Connection not established due to fatal error. */ int ConnSSL_Accept( CONNECTION *c ) { assert(c != NULL); if (!Conn_OPTION_ISSET(c, CONN_SSL)) { #ifdef HAVE_LIBGNUTLS int err = gnutls_init(&c->ssl_state.gnutls_session, GNUTLS_SERVER); if (err) { Log(LOG_ERR, "gnutls_init: %s", gnutls_strerror(err)); return false; } #endif LogDebug("ConnSSL_Accept: Initializing SSL data"); if (!ConnSSL_Init_SSL(c)) return -1; } return ConnectAccept(c, false ); } int ConnSSL_Connect( CONNECTION *c ) { assert(c != NULL); #ifdef HAVE_LIBSSL assert(c->ssl_state.ssl); #endif assert(Conn_OPTION_ISSET(c, CONN_SSL)); return ConnectAccept(c, true); } /* accept/connect wrapper. if connect is true, connect to peer, otherwise wait for incoming connection */ static int ConnectAccept( CONNECTION *c, bool connect) { int ret; #ifdef HAVE_LIBSSL SSL *ssl = c->ssl_state.ssl; assert(ssl != NULL); ret = connect ? SSL_connect(ssl) : SSL_accept(ssl); if (1 != ret) return ConnSSL_HandleError(c, ret, connect ? "SSL_connect": "SSL_accept"); #endif #ifdef HAVE_LIBGNUTLS (void) connect; ret = gnutls_handshake(c->ssl_state.gnutls_session); if (ret) return ConnSSL_HandleError(c, ret, "gnutls_handshake"); #endif /* _GNUTLS */ Conn_OPTION_DEL(c, (CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ|CONN_SSL_CONNECT)); ConnSSL_LogCertInfo(c); Conn_StartLogin(CONNECTION2ID(c)); return 1; } ssize_t ConnSSL_Write(CONNECTION *c, const void *buf, size_t count) { ssize_t bw; Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ); assert(count > 0); #ifdef HAVE_LIBSSL bw = (ssize_t) SSL_write(c->ssl_state.ssl, buf, count); #endif #ifdef HAVE_LIBGNUTLS bw = gnutls_write(c->ssl_state.gnutls_session, buf, count); #endif if (bw > 0) return bw; if (ConnSSL_HandleError( c, bw, "ConnSSL_Write") == 0) errno = EAGAIN; /* try again */ return -1; } ssize_t ConnSSL_Read(CONNECTION *c, void * buf, size_t count) { ssize_t br; Conn_OPTION_DEL(c, CONN_SSL_WANT_WRITE|CONN_SSL_WANT_READ); #ifdef HAVE_LIBSSL br = (ssize_t) SSL_read(c->ssl_state.ssl, buf, count); if (br > 0) /* on EOF we have to call ConnSSL_HandleError(), see SSL_read(3) */ return br; #endif #ifdef HAVE_LIBGNUTLS br = gnutls_read(c->ssl_state.gnutls_session, buf, count); if (br >= 0) /* on EOF we must _not_ call ConnSSL_HandleError, see gnutls_record_recv(3) */ return br; #endif /* error on read: switch ConnSSL_HandleError() return values -> 0 is "try again", so return -1 and set EAGAIN */ if (ConnSSL_HandleError(c, br, "ConnSSL_Read") == 0) { errno = EAGAIN; return -1; } return 0; } bool ConnSSL_GetCipherInfo(CONNECTION *c, char *buf, size_t len) { #ifdef HAVE_LIBSSL char *nl; SSL *ssl = c->ssl_state.ssl; if (!ssl) return false; *buf = 0; SSL_CIPHER_description(SSL_get_current_cipher(ssl), buf, len); nl = strchr(buf, '\n'); if (nl) *nl = 0; return true; #endif #ifdef HAVE_LIBGNUTLS if (Conn_OPTION_ISSET(c, CONN_SSL)) { const char *name_cipher, *name_mac, *name_proto, *name_keyexchange; unsigned keysize; gnutls_session_t sess = c->ssl_state.gnutls_session; gnutls_cipher_algorithm_t cipher = gnutls_cipher_get(sess); name_cipher = gnutls_cipher_get_name(cipher); name_mac = gnutls_mac_get_name(gnutls_mac_get(sess)); keysize = gnutls_cipher_get_key_size(cipher) * 8; name_proto = gnutls_protocol_get_name(gnutls_protocol_get_version(sess)); name_keyexchange = gnutls_kx_get_name(gnutls_kx_get(sess)); return snprintf(buf, len, "%s-%s%15s Kx=%s Enc=%s(%u) Mac=%s", name_cipher, name_mac, name_proto, name_keyexchange, name_cipher, keysize, name_mac) > 0; } return false; #endif } #else bool ConnSSL_InitLibrary(void) { return true; } #endif /* SSL_SUPPORT */ /* -eof- */