X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/e8a25e05698e39a45cf5f188476808ef3609dbdd..ff7829398d74e67f1c1f40339a772fd76708e5ac:/src/src/tls-gnu.c diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index 6d60409d7..c5a9ad096 100644 --- a/src/src/tls-gnu.c +++ b/src/src/tls-gnu.c @@ -3,9 +3,9 @@ *************************************************/ /* Copyright (c) University of Cambridge 1995 - 2018 */ -/* See the file NOTICE for conditions of use and distribution. */ - /* Copyright (c) Phil Pennock 2012 */ +/* Copyright (c) The Exim Maintainers 2020 - 2021 */ +/* See the file NOTICE for conditions of use and distribution. */ /* This file provides TLS/SSL support for Exim using the GnuTLS library, one of the available supported implementations. This file is #included into @@ -53,6 +53,9 @@ require current GnuTLS, then we'll drop support for the ancient libraries). # warning "GnuTLS library version too old; tls:cert event unsupported" # define DISABLE_EVENT #endif +#if GNUTLS_VERSION_NUMBER >= 0x030000 +# define SUPPORT_SELFSIGN /* Uncertain what version is first usable but 2.12.23 is not */ +#endif #if GNUTLS_VERSION_NUMBER >= 0x030306 # define SUPPORT_CA_DIR #else @@ -67,9 +70,30 @@ require current GnuTLS, then we'll drop support for the ancient libraries). #if GNUTLS_VERSION_NUMBER >= 0x030109 # define SUPPORT_CORK #endif +#if GNUTLS_VERSION_NUMBER >= 0x03010a +# define SUPPORT_GNUTLS_SESS_DESC +#endif +#if GNUTLS_VERSION_NUMBER >= 0x030300 +# define GNUTLS_AUTO_GLOBAL_INIT +# define GNUTLS_AUTO_PKCS11_MANUAL +#endif +#if (GNUTLS_VERSION_NUMBER >= 0x030404) \ + || (GNUTLS_VERSION_NUMBER >= 0x030311) && (GNUTLS_VERSION_NUMBER & 0xffff00 == 0x030300) +# ifndef DISABLE_OCSP +# define EXIM_HAVE_OCSP +# endif +#endif +#if GNUTLS_VERSION_NUMBER >= 0x030500 +# define SUPPORT_GNUTLS_KEYLOG +#endif #if GNUTLS_VERSION_NUMBER >= 0x030506 && !defined(DISABLE_OCSP) # define SUPPORT_SRV_OCSP_STACK #endif +#if GNUTLS_VERSION_NUMBER >= 0x030603 +# define EXIM_HAVE_TLS1_3 +# define SUPPORT_GNUTLS_EXT_RAW_PARSE +# define GNUTLS_OCSP_STATUS_REQUEST_GET2 +#endif #ifdef SUPPORT_DANE # if GNUTLS_VERSION_NUMBER >= 0x030000 @@ -83,6 +107,20 @@ require current GnuTLS, then we'll drop support for the ancient libraries). # endif #endif +#ifndef DISABLE_TLS_RESUME +# if GNUTLS_VERSION_NUMBER >= 0x030603 +# define EXIM_HAVE_TLS_RESUME +# else +# warning "GnuTLS library version too old; resumption unsupported" +# endif +#endif + +#if GNUTLS_VERSION_NUMBER >= 0x030200 +# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE +# define EXIM_HAVE_ALPN +# endif +#endif + #ifndef DISABLE_OCSP # include #endif @@ -90,6 +128,35 @@ require current GnuTLS, then we'll drop support for the ancient libraries). # include #endif +#include "tls-cipher-stdname.c" + + +#ifdef MACRO_PREDEF +void +options_tls(void) +{ +# ifndef DISABLE_TLS_RESUME +builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING ); +# endif +# ifdef EXIM_HAVE_TLS1_3 +builtin_macro_create(US"_HAVE_TLS1_3"); +# endif +# ifdef EXIM_HAVE_OCSP +builtin_macro_create(US"_HAVE_TLS_OCSP"); +# endif +# ifdef SUPPORT_SRV_OCSP_STACK +builtin_macro_create(US"_HAVE_TLS_OCSP_LIST"); +# endif +#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT) +builtin_macro_create(US"_HAVE_TLS_CA_CACHE"); +# endif +# ifdef EXIM_HAVE_ALPN +builtin_macro_create(US"_HAVE_TLS_ALPN"); +# endif +} +#else + + /* GnuTLS 2 vs 3 GnuTLS 3 only: @@ -114,20 +181,30 @@ Some of these correspond to variables in globals.c; those variables will be set to point to content in one of these instances, as appropriate for the stage of the process lifetime. -Not handled here: global tls_channelbinding_b64. +Not handled here: global tlsp->tls_channelbinding. */ typedef struct exim_gnutls_state { gnutls_session_t session; - gnutls_certificate_credentials_t x509_cred; - gnutls_priority_t priority_cache; + + exim_tlslib_state lib_state; +#define x509_cred libdata0 +#define pri_cache libdata1 + enum peer_verify_requirement verify_requirement; int fd_in; int fd_out; - BOOL peer_cert_verified; - BOOL peer_dane_verified; - BOOL trigger_sni_changes; - BOOL have_set_peerdn; + + BOOL peer_cert_verified:1; + BOOL peer_dane_verified:1; + BOOL trigger_sni_changes:1; + BOOL have_set_peerdn:1; + BOOL xfer_eof:1; /*XXX never gets set! */ + BOOL xfer_error:1; +#ifdef SUPPORT_CORK + BOOL corked:1; +#endif + const struct host_item *host; /* NULL if server */ gnutls_x509_crt_t peercert; uschar *peerdn; @@ -160,50 +237,12 @@ typedef struct exim_gnutls_state { uschar *xfer_buffer; int xfer_buffer_lwm; int xfer_buffer_hwm; - BOOL xfer_eof; /*XXX never gets set! */ - BOOL xfer_error; } exim_gnutls_state_st; static const exim_gnutls_state_st exim_gnutls_state_init = { - .session = NULL, - .x509_cred = NULL, - .priority_cache = NULL, - .verify_requirement = VERIFY_NONE, + /* all elements not explicitly intialised here get 0/NULL/FALSE */ .fd_in = -1, .fd_out = -1, - .peer_cert_verified = FALSE, - .peer_dane_verified = FALSE, - .trigger_sni_changes =FALSE, - .have_set_peerdn = FALSE, - .host = NULL, - .peercert = NULL, - .peerdn = NULL, - .ciphersuite = NULL, - .received_sni = NULL, - - .tls_certificate = NULL, - .tls_privatekey = NULL, - .tls_sni = NULL, - .tls_verify_certificates = NULL, - .tls_crl = NULL, - .tls_require_ciphers =NULL, - - .exp_tls_certificate = NULL, - .exp_tls_privatekey = NULL, - .exp_tls_verify_certificates = NULL, - .exp_tls_crl = NULL, - .exp_tls_require_ciphers = NULL, - .exp_tls_verify_cert_hostnames = NULL, -#ifndef DISABLE_EVENT - .event_action = NULL, -#endif - .tlsp = NULL, - - .xfer_buffer = NULL, - .xfer_buffer_lwm = 0, - .xfer_buffer_hwm = 0, - .xfer_eof = FALSE, - .xfer_error = FALSE, }; /* Not only do we have our own APIs which don't pass around state, assuming @@ -217,7 +256,11 @@ second connection. XXX But see gnutls_session_get_ptr() */ -static exim_gnutls_state_st state_server; +static exim_gnutls_state_st state_server = { + /* all elements not explicitly intialised here get 0/NULL/FALSE */ + .fd_in = -1, + .fd_out = -1, +}; /* dh_params are initialised once within the lifetime of a process using TLS; if we used TLS in a long-lived daemon, we'd have to reconsider this. But we @@ -225,11 +268,9 @@ don't want to repeat this. */ static gnutls_dh_params_t dh_server_params = NULL; -/* No idea how this value was chosen; preserving it. Default is 3600. */ +static int ssl_session_timeout = 7200; /* Two hours */ -static const int ssl_session_timeout = 200; - -static const char * const exim_default_gnutls_priority = "NORMAL"; +static const uschar * const exim_default_gnutls_priority = US"NORMAL"; /* Guard library core initialisation */ @@ -237,6 +278,14 @@ static BOOL exim_gnutls_base_init_done = FALSE; #ifndef DISABLE_OCSP static BOOL gnutls_buggy_ocsp = FALSE; +static BOOL exim_testharness_disable_ocsp_validity_check = FALSE; +#endif + +#ifdef EXIM_HAVE_ALPN +static int server_seen_alpn = -1; /* count of names */ +#endif +#ifdef EXIM_HAVE_TLS_RESUME +static gnutls_datum_t server_sessticket_key; #endif @@ -247,8 +296,10 @@ static BOOL gnutls_buggy_ocsp = FALSE; /* Set this to control gnutls_global_set_log_level(); values 0 to 9 will setup the library logging; a value less than 0 disables the calls to set up logging -callbacks. Possibly GNuTLS also looks for an environment variable -"GNUTLS_DEBUG_LEVEL". */ +callbacks. GNuTLS also looks for an environment variable - except not for +setuid binaries, making it useless - "GNUTLS_DEBUG_LEVEL". +Allegedly the testscript line "GNUTLS_DEBUG_LEVEL=9 sudo exim ..." would work, +but the env var must be added to /etc/sudoers too. */ #ifndef EXIM_GNUTLS_LIBRARY_LOG_LEVEL # define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1 #endif @@ -264,12 +315,7 @@ before, for now. */ # define EXIM_SERVER_DH_BITS_PRE2_12 1024 #endif -#define exim_gnutls_err_check(rc, Label) do { \ - if ((rc) != GNUTLS_E_SUCCESS) \ - return tls_error((Label), US gnutls_strerror(rc), host, errstr); \ - } while (0) - -#define expand_check_tlsvar(Varname, errstr) \ +#define Expand_check_tlsvar(Varname, errstr) \ expand_check(state->Varname, US #Varname, &state->exp_##Varname, errstr) #if GNUTLS_VERSION_NUMBER >= 0x020c00 @@ -299,16 +345,13 @@ static void exim_gnutls_logger_cb(int level, const char *message); static int exim_sni_handling_cb(gnutls_session_t session); -#ifndef DISABLE_OCSP -static int server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, - gnutls_datum_t * ocsp_response); +#ifdef EXIM_HAVE_TLS_RESUME +static int +tls_server_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when, + unsigned incoming, const gnutls_datum_t * msg); #endif - -/* ------------------------------------------------------------------------ */ -/* Static functions */ - /************************************************* * Handle TLS error * *************************************************/ @@ -341,7 +384,140 @@ return host ? FAIL : DEFER; } +static int +tls_error_gnu(exim_gnutls_state_st * state, const uschar *prefix, int err, + uschar ** errstr) +{ +return tls_error(prefix, + state && err == GNUTLS_E_FATAL_ALERT_RECEIVED + ? US gnutls_alert_get_name(gnutls_alert_get(state->session)) + : US gnutls_strerror(err), + state ? state->host : NULL, + errstr); +} + +static int +tls_error_sys(const uschar *prefix, int err, const host_item *host, + uschar ** errstr) +{ +return tls_error(prefix, US strerror(err), host, errstr); +} + + +/* ------------------------------------------------------------------------ */ +/* Initialisation */ + +#ifndef DISABLE_OCSP + +static BOOL +tls_is_buggy_ocsp(void) +{ +const uschar * s; +uschar maj, mid, mic; + +s = CUS gnutls_check_version(NULL); +maj = atoi(CCS s); +if (maj == 3) + { + while (*s && *s != '.') s++; + mid = atoi(CCS ++s); + if (mid <= 2) + return TRUE; + else if (mid >= 5) + return FALSE; + else + { + while (*s && *s != '.') s++; + mic = atoi(CCS ++s); + return mic <= (mid == 3 ? 16 : 3); + } + } +return FALSE; +} + +#endif + + +static int +tls_g_init(uschar ** errstr) +{ +int rc; +DEBUG(D_tls) debug_printf("GnuTLS global init required\n"); + +#if defined(HAVE_GNUTLS_PKCS11) && !defined(GNUTLS_AUTO_PKCS11_MANUAL) +/* By default, gnutls_global_init will init PKCS11 support in auto mode, +which loads modules from a config file, which sounds good and may be wanted +by some sysadmin, but also means in common configurations that GNOME keyring +environment variables are used and so breaks for users calling mailq. +To prevent this, we init PKCS11 first, which is the documented approach. */ + +if (!gnutls_allow_auto_pkcs11) + if ((rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL))) + return tls_error_gnu(NULL, US"gnutls_pkcs11_init", rc, errstr); +#endif + +#ifndef GNUTLS_AUTO_GLOBAL_INIT +if ((rc = gnutls_global_init())) + return tls_error_gnu(NULL, US"gnutls_global_init", rc, errstr); +#endif + +#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 +DEBUG(D_tls) + { + gnutls_global_set_log_function(exim_gnutls_logger_cb); + /* arbitrarily chosen level; bump up to 9 for more */ + gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL); + } +#endif + +#ifndef DISABLE_OCSP +if (tls_ocsp_file && (gnutls_buggy_ocsp = tls_is_buggy_ocsp())) + log_write(0, LOG_MAIN, "OCSP unusable with this GnuTLS library version"); +#endif + +exim_gnutls_base_init_done = TRUE; +return OK; +} + + + +/* Daemon-call before each connection. Nothing to do for GnuTLS. */ + +static void +tls_per_lib_daemon_tick(void) +{ +} + +/* Daemon one-time initialisation */ + +static void +tls_per_lib_daemon_init(void) +{ +uschar * dummy_errstr; +static BOOL once = FALSE; + +if (!exim_gnutls_base_init_done) + tls_g_init(&dummy_errstr); + +if (!once) + { + once = TRUE; + +#ifdef EXIM_HAVE_TLS_RESUME + /* We are dependent on the GnuTLS implementation of the Session Ticket + encryption; both the strength and the key rotation period. We hope that + the strength at least matches that of the ciphersuite (but GnuTLS does not + document this). */ + + gnutls_session_ticket_key_generate(&server_sessticket_key); /* >= 2.10.0 */ + if (f.running_in_test_harness) ssl_session_timeout = 6; +#endif + + tls_daemon_creds_reload(); + } +} +/* ------------------------------------------------------------------------ */ /************************************************* * Deal with logging errors during I/O * @@ -353,7 +529,7 @@ Argument: state the current GnuTLS exim state container rc the GnuTLS error code, or 0 if it's a local error when text identifying read or write - text local error text when ec is 0 + text local error text when rc is 0 Returns: nothing */ @@ -364,11 +540,14 @@ record_io_error(exim_gnutls_state_st *state, int rc, uschar *when, uschar *text) const uschar * msg; uschar * errstr; -if (rc == GNUTLS_E_FATAL_ALERT_RECEIVED) - msg = string_sprintf("%s: %s", US gnutls_strerror(rc), - US gnutls_alert_get_name(gnutls_alert_get(state->session))); -else - msg = US gnutls_strerror(rc); +msg = rc == GNUTLS_E_FATAL_ALERT_RECEIVED + ? string_sprintf("A TLS fatal alert has been received: %s", + US gnutls_alert_get_name(gnutls_alert_get(state->session))) +#ifdef GNUTLS_E_PREMATURE_TERMINATION + : rc == GNUTLS_E_PREMATURE_TERMINATION && errno + ? string_sprintf("%s: syscall: %s", US gnutls_strerror(rc), strerror(errno)) +#endif + : US gnutls_strerror(rc); (void) tls_error(when, msg, state->host, &errstr); @@ -430,7 +609,8 @@ Sets: tls_active fd tls_bits strength indicator tls_certificate_verified bool indicator - tls_channelbinding_b64 for some SASL mechanisms + tls_channelbinding for some SASL mechanisms + tls_ver a string tls_cipher a string tls_peercert pointer to library internal tls_peerdn a string @@ -444,7 +624,6 @@ Argument: static void extract_exim_vars_from_tls_state(exim_gnutls_state_st * state) { -gnutls_cipher_algorithm_t cipher; #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING int old_pool; int rc; @@ -455,12 +634,6 @@ tls_support * tlsp = state->tlsp; tlsp->active.sock = state->fd_out; tlsp->active.tls_ctx = state; -cipher = gnutls_cipher_get(state->session); -/* returns size in "bytes" */ -tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; - -tlsp->cipher = state->ciphersuite; - DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite); tlsp->certificate_verified = state->peer_cert_verified; @@ -468,10 +641,10 @@ tlsp->certificate_verified = state->peer_cert_verified; tlsp->dane_verified = state->peer_dane_verified; #endif -/* note that tls_channelbinding_b64 is not saved to the spool file, since it's +/* note that tls_channelbinding is not saved to the spool file, since it's only available for use for authenticators while this TLS session is running. */ -tls_channelbinding_b64 = NULL; +tlsp->channelbinding = NULL; #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING channel.data = NULL; channel.size = 0; @@ -479,17 +652,24 @@ if ((rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, & { DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); } else { + /* Declare the taintedness of the binding info. On server, untainted; on + client, tainted - being the Finish msg from the server. */ + old_pool = store_pool; store_pool = POOL_PERM; - tls_channelbinding_b64 = b64encode(CUS channel.data, (int)channel.size); + tlsp->channelbinding = b64encode_taint(CUS channel.data, (int)channel.size, + !!state->host); store_pool = old_pool; - DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n"); + DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage\n"); } #endif /* peercert is set in peer_status() */ tlsp->peerdn = state->peerdn; -tlsp->sni = state->received_sni; + +/* do not corrupt sni sent by client; record sni rxd by server */ +if (!state->host) + tlsp->sni = state->received_sni; /* record our certificate */ { @@ -531,13 +711,12 @@ uschar *filename = NULL; size_t sz; uschar *exp_tls_dhparam; BOOL use_file_in_spool = FALSE; -BOOL use_fixed_file = FALSE; host_item *host = NULL; /* dummy for macros */ -DEBUG(D_tls) debug_printf("Initialising GnuTLS server params.\n"); +DEBUG(D_tls) debug_printf("Initialising GnuTLS server params\n"); -rc = gnutls_dh_params_init(&dh_server_params); -exim_gnutls_err_check(rc, US"gnutls_dh_params_init"); +if ((rc = gnutls_dh_params_init(&dh_server_params))) + return tls_error_gnu(NULL, US"gnutls_dh_params_init", rc, errstr); m.data = NULL; m.size = 0; @@ -555,7 +734,7 @@ else if (Ustrcmp(exp_tls_dhparam, "historic") == 0) use_file_in_spool = TRUE; else if (Ustrcmp(exp_tls_dhparam, "none") == 0) { - DEBUG(D_tls) debug_printf("Requested no DH parameters.\n"); + DEBUG(D_tls) debug_printf("Requested no DH parameters\n"); return OK; } else if (exp_tls_dhparam[0] != '/') @@ -565,15 +744,12 @@ else if (exp_tls_dhparam[0] != '/') m.size = Ustrlen(m.data); } else - { - use_fixed_file = TRUE; filename = exp_tls_dhparam; - } if (m.data) { - rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM); - exim_gnutls_err_check(rc, US"gnutls_dh_params_import_pkcs3"); + if ((rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM))) + return tls_error_gnu(NULL, US"gnutls_dh_params_import_pkcs3", rc, errstr); DEBUG(D_tls) debug_printf("Loaded fixed standard D-H parameters\n"); return OK; } @@ -581,16 +757,16 @@ if (m.data) #ifdef HAVE_GNUTLS_SEC_PARAM_CONSTANTS /* If you change this constant, also change dh_param_fn_ext so that we can use a different filename and ensure we have sufficient bits. */ -dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL); -if (!dh_bits) + +if (!(dh_bits = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_NORMAL))) return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL, errstr); DEBUG(D_tls) - debug_printf("GnuTLS tells us that for D-H PK, NORMAL is %d bits.\n", + debug_printf("GnuTLS tells us that for D-H PK, NORMAL is %d bits\n", dh_bits); #else dh_bits = EXIM_SERVER_DH_BITS_PRE2_12; DEBUG(D_tls) - debug_printf("GnuTLS lacks gnutls_sec_param_to_pk_bits(), using %d bits.\n", + debug_printf("GnuTLS lacks gnutls_sec_param_to_pk_bits(), using %d bits\n", dh_bits); #endif @@ -598,7 +774,7 @@ DEBUG(D_tls) if (dh_bits > tls_dh_max_bits) { DEBUG(D_tls) - debug_printf("tls_dh_max_bits clamping override, using %d bits instead.\n", + debug_printf("tls_dh_max_bits clamping override, using %d bits instead\n", tls_dh_max_bits); dh_bits = tls_dh_max_bits; } @@ -624,7 +800,7 @@ if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) { saved_errno = errno; (void)close(fd); - return tls_error(US"TLS cache stat failed", US strerror(saved_errno), NULL, errstr); + return tls_error_sys(US"TLS cache stat failed", saved_errno, NULL, errstr); } if (!S_ISREG(statbuf.st_mode)) { @@ -635,28 +811,29 @@ if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) { saved_errno = errno; (void)close(fd); - return tls_error(US"fdopen(TLS cache stat fd) failed", - US strerror(saved_errno), NULL, errstr); + return tls_error_sys(US"fdopen(TLS cache stat fd) failed", + saved_errno, NULL, errstr); } m.size = statbuf.st_size; - if (!(m.data = malloc(m.size))) + if (!(m.data = store_malloc(m.size))) { fclose(fp); - return tls_error(US"malloc failed", US strerror(errno), NULL, errstr); + return tls_error_sys(US"malloc failed", errno, NULL, errstr); } if (!(sz = fread(m.data, m.size, 1, fp))) { saved_errno = errno; fclose(fp); - free(m.data); - return tls_error(US"fread failed", US strerror(saved_errno), NULL, errstr); + store_free(m.data); + return tls_error_sys(US"fread failed", saved_errno, NULL, errstr); } fclose(fp); rc = gnutls_dh_params_import_pkcs3(dh_server_params, &m, GNUTLS_X509_FMT_PEM); - free(m.data); - exim_gnutls_err_check(rc, US"gnutls_dh_params_import_pkcs3"); + store_free(m.data); + if (rc) + return tls_error_gnu(NULL, US"gnutls_dh_params_import_pkcs3", rc, errstr); DEBUG(D_tls) debug_printf("read D-H parameters from file \"%s\"\n", filename); } @@ -670,7 +847,7 @@ else if (errno == ENOENT) debug_printf("D-H parameter cache file \"%s\" does not exist\n", filename); } else - return tls_error(string_open_failed(errno, "\"%s\" for reading", filename), + return tls_error(string_open_failed("\"%s\" for reading", filename), NULL, NULL, errstr); /* If ret < 0, either the cache file does not exist, or the data it contains @@ -688,10 +865,10 @@ if (rc < 0) return tls_error(US"Filename too long to generate replacement", filename, NULL, errstr); - temp_fn = string_copy(US"%s.XXXXXXX"); + temp_fn = string_copy(US"exim-dh.XXXXXXX"); if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */ - return tls_error(US"Unable to open temp file", US strerror(errno), NULL, errstr); - (void)fchown(fd, exim_uid, exim_gid); /* Probably not necessary */ + return tls_error_sys(US"Unable to open temp file", errno, NULL, errstr); + (void)exim_chown(temp_fn, exim_uid, exim_gid); /* Probably not necessary */ /* GnuTLS overshoots! * If we ask for 2236, we might get 2237 or more. @@ -712,8 +889,8 @@ if (rc < 0) DEBUG(D_tls) debug_printf("requesting generation of %d bit Diffie-Hellman prime ...\n", dh_bits_gen); - rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen); - exim_gnutls_err_check(rc, US"gnutls_dh_params_generate2"); + if ((rc = gnutls_dh_params_generate2(dh_server_params, dh_bits_gen))) + return tls_error_gnu(NULL, US"gnutls_dh_params_generate2", rc, errstr); /* gnutls_dh_params_export_pkcs3() will tell us the exact size, every time, and I confirmed that a NULL call to get the size first is how the GnuTLS @@ -721,41 +898,41 @@ if (rc < 0) sz = 0; m.data = NULL; - rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, - m.data, &sz); - if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) - exim_gnutls_err_check(rc, US"gnutls_dh_params_export_pkcs3(NULL) sizing"); + if ( (rc = gnutls_dh_params_export_pkcs3(dh_server_params, + GNUTLS_X509_FMT_PEM, m.data, &sz)) + && rc != GNUTLS_E_SHORT_MEMORY_BUFFER) + return tls_error_gnu(NULL, US"gnutls_dh_params_export_pkcs3(NULL) sizing", + rc, errstr); m.size = sz; - if (!(m.data = malloc(m.size))) - return tls_error(US"memory allocation failed", US strerror(errno), NULL, errstr); + if (!(m.data = store_malloc(m.size))) + return tls_error_sys(US"memory allocation failed", errno, NULL, errstr); /* this will return a size 1 less than the allocation size above */ - rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, - m.data, &sz); - if (rc != GNUTLS_E_SUCCESS) + if ((rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, + m.data, &sz))) { - free(m.data); - exim_gnutls_err_check(rc, US"gnutls_dh_params_export_pkcs3() real"); + store_free(m.data); + return tls_error_gnu(NULL, US"gnutls_dh_params_export_pkcs3() real", rc, errstr); } m.size = sz; /* shrink by 1, probably */ if ((sz = write_to_fd_buf(fd, m.data, (size_t) m.size)) != m.size) { - free(m.data); - return tls_error(US"TLS cache write D-H params failed", - US strerror(errno), NULL, errstr); + store_free(m.data); + return tls_error_sys(US"TLS cache write D-H params failed", + errno, NULL, errstr); } - free(m.data); + store_free(m.data); if ((sz = write_to_fd_buf(fd, US"\n", 1)) != 1) - return tls_error(US"TLS cache write D-H params final newline failed", - US strerror(errno), NULL, errstr); + return tls_error_sys(US"TLS cache write D-H params final newline failed", + errno, NULL, errstr); if ((rc = close(fd))) - return tls_error(US"TLS cache write close() failed", US strerror(errno), NULL, errstr); + return tls_error_sys(US"TLS cache write close() failed", errno, NULL, errstr); if (Urename(temp_fn, filename) < 0) - return tls_error(string_sprintf("failed to rename \"%s\" as \"%s\"", - temp_fn, filename), US strerror(errno), NULL, errstr); + return tls_error_sys(string_sprintf("failed to rename \"%s\" as \"%s\"", + temp_fn, filename), errno, NULL, errstr); DEBUG(D_tls) debug_printf("wrote D-H parameters to file \"%s\"\n", filename); } @@ -767,7 +944,7 @@ return OK; -/* Create and install a selfsigned certificate, for use in server mode */ +/* Create and install a selfsigned certificate, for use in server mode. */ static int tls_install_selfsign(exim_gnutls_state_st * state, uschar ** errstr) @@ -778,13 +955,20 @@ gnutls_x509_privkey_t pkey = NULL; const uschar * where; int rc; +#ifndef SUPPORT_SELFSIGN +where = US"library too old"; +rc = GNUTLS_E_NO_CERTIFICATE_FOUND; +if (TRUE) goto err; +#endif + +DEBUG(D_tls) debug_printf("TLS: generating selfsigned server cert\n"); where = US"initialising pkey"; if ((rc = gnutls_x509_privkey_init(&pkey))) goto err; where = US"initialising cert"; if ((rc = gnutls_x509_crt_init(&cert))) goto err; -where = US"generating pkey"; +where = US"generating pkey"; /* Hangs on 2.12.23 */ if ((rc = gnutls_x509_privkey_generate(pkey, GNUTLS_PK_RSA, #ifdef SUPPORT_PARAM_TO_PK_BITS # ifndef GNUTLS_SEC_PARAM_MEDIUM @@ -802,7 +986,7 @@ now = 1; if ( (rc = gnutls_x509_crt_set_version(cert, 3)) || (rc = gnutls_x509_crt_set_serial(cert, &now, sizeof(now))) || (rc = gnutls_x509_crt_set_activation_time(cert, now = time(NULL))) - || (rc = gnutls_x509_crt_set_expiration_time(cert, now + 60 * 60)) /* 1 hr */ + || (rc = gnutls_x509_crt_set_expiration_time(cert, (long)2 * 60 * 60)) /* 2 hour */ || (rc = gnutls_x509_crt_set_key(cert, pkey)) || (rc = gnutls_x509_crt_set_dn_by_oid(cert, @@ -820,7 +1004,8 @@ if ((rc = gnutls_x509_crt_sign(cert, cert, pkey))) goto err; where = US"installing selfsign cert"; /* Since: 2.4.0 */ -if ((rc = gnutls_certificate_set_x509_key(state->x509_cred, &cert, 1, pkey))) +if ((rc = gnutls_certificate_set_x509_key(state->lib_state.x509_cred, + &cert, 1, pkey))) goto err; rc = OK; @@ -831,7 +1016,7 @@ out: return rc; err: - rc = tls_error(where, US gnutls_strerror(rc), NULL, errstr); + rc = tls_error_gnu(state, where, rc, errstr); goto out; } @@ -847,313 +1032,893 @@ Return: static int tls_add_certfile(exim_gnutls_state_st * state, const host_item * host, - uschar * certfile, uschar * keyfile, uschar ** errstr) + const uschar * certfile, const uschar * keyfile, uschar ** errstr) { -int rc = gnutls_certificate_set_x509_key_file(state->x509_cred, - CS certfile, CS keyfile, GNUTLS_X509_FMT_PEM); +int rc = gnutls_certificate_set_x509_key_file(state->lib_state.x509_cred, + CCS certfile, CCS keyfile, GNUTLS_X509_FMT_PEM); if (rc < 0) - return tls_error( + return tls_error_gnu(state, string_sprintf("cert/key setup: cert=%s key=%s", certfile, keyfile), - US gnutls_strerror(rc), host, errstr); + rc, errstr); return -rc; } -/************************************************* -* Variables re-expanded post-SNI * -*************************************************/ - -/* Called from both server and client code, via tls_init(), and also from -the SNI callback after receiving an SNI, if tls_certificate includes "tls_sni". +#if !defined(DISABLE_OCSP) && !defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) +/* Load an OCSP proof from file for sending by the server. Called +on getting a status-request handshake message, for earlier versions +of GnuTLS. */ -We can tell the two apart by state->received_sni being non-NULL in callback. +static int +server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, + gnutls_datum_t * ocsp_response) +{ +int ret; +DEBUG(D_tls) debug_printf("OCSP stapling callback: %s\n", US ptr); -The callback should not call us unless state->trigger_sni_changes is true, -which we are responsible for setting on the first pass through. +if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0) + { + DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n", + CS ptr); + tls_in.ocsp = OCSP_NOT_RESP; + return GNUTLS_E_NO_CERTIFICATE_STATUS; + } -Arguments: - state exim_gnutls_state_st * - errstr error string pointer +tls_in.ocsp = OCSP_VFY_NOT_TRIED; +return 0; +} +#endif -Returns: OK/DEFER/FAIL -*/ +#ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE +/* Make a note that we saw a status-request */ static int -tls_expand_session_files(exim_gnutls_state_st * state, uschar ** errstr) +tls_server_clienthello_ext(void * ctx, unsigned tls_id, + const uschar * data, unsigned size) { -struct stat statbuf; -int rc; -const host_item *host = state->host; /* macro should be reconsidered? */ -uschar *saved_tls_certificate = NULL; -uschar *saved_tls_privatekey = NULL; -uschar *saved_tls_verify_certificates = NULL; -uschar *saved_tls_crl = NULL; -int cert_count; - -/* We check for tls_sni *before* expansion. */ -if (!host) /* server */ - if (!state->received_sni) - { - if ( state->tls_certificate - && ( Ustrstr(state->tls_certificate, US"tls_sni") - || Ustrstr(state->tls_certificate, US"tls_in_sni") - || Ustrstr(state->tls_certificate, US"tls_out_sni") - ) ) +/* The values for tls_id are documented here: +https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */ +switch (tls_id) + { + case 5: /* Status Request */ + DEBUG(D_tls) debug_printf("Seen status_request extension from client\n"); + tls_in.ocsp = OCSP_NOT_RESP; + break; +#ifdef EXIM_HAVE_ALPN + case 16: /* Application Layer Protocol Notification */ + /* The format of "data" here doesn't seem to be documented, but appears + to be a 2-byte field with a (redundant, given the "size" arg) total length + then a sequence of one-byte size then string (not nul-term) names. The + latter is as described in OpenSSL documentation. */ + + DEBUG(D_tls) debug_printf("Seen ALPN extension from client (s=%u):", size); + for (const uschar * s = data+2; s-data < size-1; s += *s + 1) { - DEBUG(D_tls) debug_printf("We will re-expand TLS session files if we receive SNI.\n"); - state->trigger_sni_changes = TRUE; + server_seen_alpn++; + DEBUG(D_tls) debug_printf(" '%.*s'", (int)*s, s+1); } - } - else - { - /* useful for debugging */ - saved_tls_certificate = state->exp_tls_certificate; - saved_tls_privatekey = state->exp_tls_privatekey; - saved_tls_verify_certificates = state->exp_tls_verify_certificates; - saved_tls_crl = state->exp_tls_crl; - } - -rc = gnutls_certificate_allocate_credentials(&state->x509_cred); -exim_gnutls_err_check(rc, US"gnutls_certificate_allocate_credentials"); - -#ifdef SUPPORT_SRV_OCSP_STACK -gnutls_certificate_set_flags(state->x509_cred, GNUTLS_CERTIFICATE_API_V2); + DEBUG(D_tls) debug_printf("\n"); + if (server_seen_alpn > 1) + { + DEBUG(D_tls) debug_printf("TLS: too many ALPNs presented in handshake\n"); + return GNUTLS_E_NO_APPLICATION_PROTOCOL; + } + break; #endif + } +return 0; +} -/* remember: expand_check_tlsvar() is expand_check() but fiddling with -state members, assuming consistent naming; and expand_check() returns -false if expansion failed, unless expansion was forced to fail. */ - -/* check if we at least have a certificate, before doing expensive -D-H generation. */ - -if (!expand_check_tlsvar(tls_certificate, errstr)) - return DEFER; - -/* certificate is mandatory in server, optional in client */ - -if ( !state->exp_tls_certificate - || !*state->exp_tls_certificate - ) - if (!host) - return tls_install_selfsign(state, errstr); - else - DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n"); - -if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr)) - return DEFER; +/* Callback for client-hello, on server, if we think we might serve stapled-OCSP */ +static int +tls_server_clienthello_cb(gnutls_session_t session, unsigned int htype, + unsigned when, unsigned int incoming, const gnutls_datum_t * msg) +{ +/* Call fn for each extension seen. 3.6.3 onwards */ +return gnutls_ext_raw_parse(NULL, tls_server_clienthello_ext, msg, + GNUTLS_EXT_RAW_FLAG_TLS_CLIENT_HELLO); +} -/* tls_privatekey is optional, defaulting to same file as certificate */ -if (state->tls_privatekey == NULL || *state->tls_privatekey == '\0') +# ifdef notdef_crashes +/* Make a note that we saw a status-response */ +static int +tls_server_servercerts_ext(void * ctx, unsigned tls_id, + const unsigned char *data, unsigned size) +{ +/* debug_printf("%s %u\n", __FUNCTION__, tls_id); */ +/* https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */ +if (FALSE && tls_id == 5) /* status_request */ { - state->tls_privatekey = state->tls_certificate; - state->exp_tls_privatekey = state->exp_tls_certificate; + DEBUG(D_tls) debug_printf("Seen status_request extension\n"); + tls_in.ocsp = exim_testharness_disable_ocsp_validity_check + ? OCSP_VFY_NOT_TRIED : OCSP_VFIED; /* We know that GnuTLS verifies responses */ } +return 0; +} +# endif +/* Callback for certificates packet, on server, if we think we might serve stapled-OCSP */ +static int +tls_server_servercerts_cb(gnutls_session_t session, unsigned int htype, + unsigned when, unsigned int incoming, const gnutls_datum_t * msg) +{ +/* Call fn for each extension seen. 3.6.3 onwards */ +# ifdef notdef_crashes + /*XXX crashes */ +return gnutls_ext_raw_parse(NULL, tls_server_servercerts_ext, msg, 0); +# endif +} +#endif /*SUPPORT_GNUTLS_EXT_RAW_PARSE*/ -if (state->exp_tls_certificate && *state->exp_tls_certificate) - { - DEBUG(D_tls) debug_printf("certificate file = %s\nkey file = %s\n", - state->exp_tls_certificate, state->exp_tls_privatekey); +/*XXX in tls1.3 the cert-status travel as an extension next to the cert, in the + "Handshake Protocol: Certificate" record. +So we need to spot the Certificate handshake message, parse it and spot any status_request extension(s) - if (state->received_sni) - if ( Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0 - && Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0 - ) - { - DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n"); - } - else - { - DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n"); - } +This is different to tls1.2 - where it is a separate record (wireshark term) / handshake message (gnutls term). +*/ - if (!host) /* server */ +#if defined(EXIM_HAVE_TLS_RESUME) || defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) +/* Callback for certificate-status, on server. We sent stapled OCSP. */ +static int +tls_server_certstatus_cb(gnutls_session_t session, unsigned int htype, + unsigned when, unsigned int incoming, const gnutls_datum_t * msg) +{ +DEBUG(D_tls) debug_printf("Sending certificate-status\n"); /*XXX we get this for tls1.2 but not for 1.3 */ +# ifdef SUPPORT_SRV_OCSP_STACK +tls_in.ocsp = exim_testharness_disable_ocsp_validity_check + ? OCSP_VFY_NOT_TRIED : OCSP_VFIED; /* We know that GnuTLS verifies responses */ +# else +tls_in.ocsp = OCSP_VFY_NOT_TRIED; +# endif +return 0; +} + +/* Callback for handshake messages, on server */ +static int +tls_server_hook_cb(gnutls_session_t sess, u_int htype, unsigned when, + unsigned incoming, const gnutls_datum_t * msg) +{ +/* debug_printf("%s: htype %u\n", __FUNCTION__, htype); */ +switch (htype) + { +# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE + case GNUTLS_HANDSHAKE_CLIENT_HELLO: + return tls_server_clienthello_cb(sess, htype, when, incoming, msg); + case GNUTLS_HANDSHAKE_CERTIFICATE_PKT: + return tls_server_servercerts_cb(sess, htype, when, incoming, msg); +# endif + case GNUTLS_HANDSHAKE_CERTIFICATE_STATUS: + return tls_server_certstatus_cb(sess, htype, when, incoming, msg); +# ifdef EXIM_HAVE_TLS_RESUME + case GNUTLS_HANDSHAKE_NEW_SESSION_TICKET: + return tls_server_ticket_cb(sess, htype, when, incoming, msg); +# endif + default: + return 0; + } +} +#endif + + +#if !defined(DISABLE_OCSP) && defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) +static void +tls_server_testharness_ocsp_fiddle(void) +{ +extern char ** environ; +if (environ) for (uschar ** p = USS environ; *p; p++) + if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) { - const uschar * clist = state->exp_tls_certificate; - const uschar * klist = state->exp_tls_privatekey; - const uschar * olist; - int csep = 0, ksep = 0, osep = 0, cnt = 0; - uschar * cfile, * kfile, * ofile; + DEBUG(D_tls) debug_printf("Permitting known bad OCSP response\n"); + exim_testharness_disable_ocsp_validity_check = TRUE; + } +} +#endif + +/************************************************** +* One-time init credentials for server and client * +**************************************************/ + +static void +creds_basic_init(gnutls_certificate_credentials_t x509_cred, BOOL server) +{ +#ifdef SUPPORT_SRV_OCSP_STACK +gnutls_certificate_set_flags(x509_cred, GNUTLS_CERTIFICATE_API_V2); + +# if !defined(DISABLE_OCSP) && defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) +if (server && tls_ocsp_file) + { + if (f.running_in_test_harness) + tls_server_testharness_ocsp_fiddle(); + + if (exim_testharness_disable_ocsp_validity_check) + gnutls_certificate_set_flags(x509_cred, + GNUTLS_CERTIFICATE_API_V2 | GNUTLS_CERTIFICATE_SKIP_OCSP_RESPONSE_CHECK); + } +# endif +#endif +DEBUG(D_tls) + debug_printf("TLS: basic cred init, %s\n", server ? "server" : "client"); +} +static int +creds_load_server_certs(exim_gnutls_state_st * state, const uschar * cert, + const uschar * pkey, const uschar * ocsp, uschar ** errstr) +{ +const uschar * clist = cert; +const uschar * klist = pkey; +const uschar * olist; +int csep = 0, ksep = 0, osep = 0, cnt = 0, rc; +uschar * cfile, * kfile, * ofile; #ifndef DISABLE_OCSP - if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", &ofile, errstr)) - return DEFER; - olist = ofile; +# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE +gnutls_x509_crt_fmt_t ocsp_fmt = GNUTLS_X509_FMT_DER; +# endif + +if (!expand_check(ocsp, US"tls_ocsp_file", &ofile, errstr)) + return DEFER; +olist = ofile; #endif - while (cfile = string_nextinlist(&clist, &csep, NULL, 0)) +while (cfile = string_nextinlist(&clist, &csep, NULL, 0)) - if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0))) - return tls_error(US"cert/key setup: out of keys", NULL, host, errstr); - else if (0 < (rc = tls_add_certfile(state, host, cfile, kfile, errstr))) - return rc; - else + if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0))) + return tls_error(US"cert/key setup: out of keys", NULL, NULL, errstr); + else if ((rc = tls_add_certfile(state, NULL, cfile, kfile, errstr)) > 0) + return rc; + else + { + int gnutls_cert_index = -rc; + DEBUG(D_tls) debug_printf("TLS: cert/key %d %s registered\n", + gnutls_cert_index, cfile); + +#ifndef DISABLE_OCSP + if (ocsp) + { + /* Set the OCSP stapling server info */ + if (gnutls_buggy_ocsp) + { + DEBUG(D_tls) + debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); + } + else if ((ofile = string_nextinlist(&olist, &osep, NULL, 0))) { - int gnutls_cert_index = -rc; - DEBUG(D_tls) debug_printf("TLS: cert/key %s registered\n", cfile); + DEBUG(D_tls) debug_printf("OCSP response file %d = %s\n", + gnutls_cert_index, ofile); +# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE + if (Ustrncmp(ofile, US"PEM ", 4) == 0) + { + ocsp_fmt = GNUTLS_X509_FMT_PEM; + ofile += 4; + } + else if (Ustrncmp(ofile, US"DER ", 4) == 0) + { + ocsp_fmt = GNUTLS_X509_FMT_DER; + ofile += 4; + } - /* Set the OCSP stapling server info */ + if ((rc = gnutls_certificate_set_ocsp_status_request_file2( + state->lib_state.x509_cred, CCS ofile, gnutls_cert_index, + ocsp_fmt)) < 0) + return tls_error_gnu(state, + US"gnutls_certificate_set_ocsp_status_request_file2", + rc, errstr); + DEBUG(D_tls) + debug_printf(" %d response%s loaded\n", rc, rc>1 ? "s":""); -#ifndef DISABLE_OCSP - if (tls_ocsp_file) - if (gnutls_buggy_ocsp) + /* Arrange callbacks for OCSP request observability */ + + if (state->session) + gnutls_handshake_set_hook_function(state->session, + GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb); + else + state->lib_state.ocsp_hook = TRUE; + + +# else +# if defined(SUPPORT_SRV_OCSP_STACK) + if ((rc = gnutls_certificate_set_ocsp_status_request_function2( + state->lib_state.x509_cred, gnutls_cert_index, + server_ocsp_stapling_cb, ofile))) + return tls_error_gnu(state, + US"gnutls_certificate_set_ocsp_status_request_function2", + rc, errstr); + else +# endif + { + if (cnt++ > 0) { DEBUG(D_tls) - debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); + debug_printf("oops; multiple OCSP files not supported\n"); + break; } - else if ((ofile = string_nextinlist(&olist, &osep, NULL, 0))) - { - /* Use the full callback method for stapling just to get - observability. More efficient would be to read the file once only, - if it never changed (due to SNI). Would need restart on file update, - or watch datestamp. */ + gnutls_certificate_set_ocsp_status_request_function( + state->lib_state.x509_cred, server_ocsp_stapling_cb, ofile); + } +# endif /* SUPPORT_GNUTLS_EXT_RAW_PARSE */ + } + else + DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n"); + } +#endif /* DISABLE_OCSP */ + } +return 0; +} -# ifdef SUPPORT_SRV_OCSP_STACK - rc = gnutls_certificate_set_ocsp_status_request_function2( - state->x509_cred, gnutls_cert_index, - server_ocsp_stapling_cb, ofile); +static int +creds_load_client_certs(exim_gnutls_state_st * state, const host_item * host, + const uschar * cert, const uschar * pkey, uschar ** errstr) +{ +int rc = tls_add_certfile(state, host, cert, pkey, errstr); +if (rc > 0) return rc; +DEBUG(D_tls) debug_printf("TLS: cert/key registered\n"); +return 0; +} + +static int +creds_load_cabundle(exim_gnutls_state_st * state, const uschar * bundle, + const host_item * host, uschar ** errstr) +{ +int cert_count; +struct stat statbuf; + +#ifdef SUPPORT_SYSDEFAULT_CABUNDLE +if (Ustrcmp(bundle, "system") == 0 || Ustrncmp(bundle, "system,", 7) == 0) + cert_count = gnutls_certificate_set_x509_system_trust(state->lib_state.x509_cred); +else +#endif + { + if (Ustat(bundle, &statbuf) < 0) + { + log_write(0, LOG_MAIN|LOG_PANIC, "could not stat '%s' " + "(tls_verify_certificates): %s", bundle, strerror(errno)); + return DEFER; + } + +#ifndef SUPPORT_CA_DIR + /* The test suite passes in /dev/null; we could check for that path explicitly, + but who knows if someone has some weird FIFO which always dumps some certs, or + other weirdness. The thing we really want to check is that it's not a + directory, since while OpenSSL supports that, GnuTLS does not. + So s/!S_ISREG/S_ISDIR/ and change some messaging ... */ + if (S_ISDIR(statbuf.st_mode)) + { + log_write(0, LOG_MAIN|LOG_PANIC, + "tls_verify_certificates \"%s\" is a directory", bundle); + return DEFER; + } +#endif + + DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n", + bundle, statbuf.st_size); + + if (statbuf.st_size == 0) + { + DEBUG(D_tls) + debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n"); + return OK; + } + + cert_count = + +#ifdef SUPPORT_CA_DIR + (statbuf.st_mode & S_IFMT) == S_IFDIR + ? + gnutls_certificate_set_x509_trust_dir(state->lib_state.x509_cred, + CS bundle, GNUTLS_X509_FMT_PEM) + : +#endif + gnutls_certificate_set_x509_trust_file(state->lib_state.x509_cred, + CS bundle, GNUTLS_X509_FMT_PEM); + +#ifdef SUPPORT_CA_DIR + /* Mimic the behaviour with OpenSSL of not advertising a usable-cert list + when using the directory-of-certs config model. */ + + if ((statbuf.st_mode & S_IFMT) == S_IFDIR) + if (state->session) + gnutls_certificate_send_x509_rdn_sequence(state->session, 1); + else + state->lib_state.ca_rdn_emulate = TRUE; +#endif + } + +if (cert_count < 0) + return tls_error_gnu(state, US"setting certificate trust", cert_count, errstr); +DEBUG(D_tls) + debug_printf("Added %d certificate authorities\n", cert_count); - exim_gnutls_err_check(rc, - US"gnutls_certificate_set_ocsp_status_request_function2"); +return OK; +} + + +static int +creds_load_crl(exim_gnutls_state_st * state, const uschar * crl, uschar ** errstr) +{ +int cert_count; +DEBUG(D_tls) debug_printf("loading CRL file = %s\n", crl); +if ((cert_count = gnutls_certificate_set_x509_crl_file(state->lib_state.x509_cred, + CS crl, GNUTLS_X509_FMT_PEM)) < 0) + return tls_error_gnu(state, US"gnutls_certificate_set_x509_crl_file", + cert_count, errstr); + +DEBUG(D_tls) debug_printf("Processed %d CRLs\n", cert_count); +return OK; +} + + +static int +creds_load_pristring(exim_gnutls_state_st * state, const uschar * p, + const char ** errpos) +{ +if (!p) + { + p = exim_default_gnutls_priority; + DEBUG(D_tls) + debug_printf("GnuTLS using default session cipher/priority \"%s\"\n", p); + } +return gnutls_priority_init( (gnutls_priority_t *) &state->lib_state.pri_cache, + CCS p, errpos); +} + +static unsigned +tls_server_creds_init(void) +{ +uschar * dummy_errstr; +unsigned lifetime = 0; + +state_server.lib_state = null_tls_preload; +if (gnutls_certificate_allocate_credentials( + (gnutls_certificate_credentials_t *) &state_server.lib_state.x509_cred)) + { + state_server.lib_state.x509_cred = NULL; + return lifetime; + } +creds_basic_init(state_server.lib_state.x509_cred, TRUE); + +#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT) +/* If tls_certificate has any $ indicating expansions, it is not good. +If tls_privatekey is set but has $, not good. Likewise for tls_ocsp_file. +If all good (and tls_certificate set), load the cert(s). */ + +if ( opt_set_and_noexpand(tls_certificate) +# ifndef DISABLE_OCSP + && opt_unset_or_noexpand(tls_ocsp_file) +# endif + && opt_unset_or_noexpand(tls_privatekey)) + { + /* Set watches on the filenames. The implementation does de-duplication + so we can just blindly do them all. + */ + + if ( tls_set_watch(tls_certificate, TRUE) +# ifndef DISABLE_OCSP + && tls_set_watch(tls_ocsp_file, TRUE) +# endif + && tls_set_watch(tls_privatekey, TRUE)) + { + DEBUG(D_tls) debug_printf("TLS: preloading server certs\n"); + if (creds_load_server_certs(&state_server, tls_certificate, + tls_privatekey && *tls_privatekey ? tls_privatekey : tls_certificate, +# ifdef DISABLE_OCSP + NULL, # else - if (cnt++ > 0) - { - DEBUG(D_tls) - debug_printf("oops; multiple OCSP files not supported\n"); - break; - } - gnutls_certificate_set_ocsp_status_request_function( - state->x509_cred, server_ocsp_stapling_cb, ofile); + tls_ocsp_file, # endif + &dummy_errstr) == 0) + state_server.lib_state.conn_certs = TRUE; + } + } +else if ( !tls_certificate && !tls_privatekey +# ifndef DISABLE_OCSP + && !tls_ocsp_file +# endif + ) + { /* Generate & preload a selfsigned cert. No files to watch. */ + if ((tls_install_selfsign(&state_server, &dummy_errstr)) == OK) + { + state_server.lib_state.conn_certs = TRUE; + lifetime = f.running_in_test_harness ? 2 : 60 * 60; /* 1 hour */ + } + } +else + DEBUG(D_tls) debug_printf("TLS: not preloading server certs\n"); - DEBUG(D_tls) debug_printf("OCSP response file = %s\n", ofile); - } - else - DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n"); +/* If tls_verify_certificates is non-empty and has no $, load CAs. +If none was configured and we can't handle "system", treat as empty. */ + +if ( opt_set_and_noexpand(tls_verify_certificates) +#ifndef SUPPORT_SYSDEFAULT_CABUNDLE + && Ustrcmp(tls_verify_certificates, "system") != 0 #endif + ) + { + if (tls_set_watch(tls_verify_certificates, FALSE)) + { + DEBUG(D_tls) debug_printf("TLS: preloading CA bundle for server\n"); + if (creds_load_cabundle(&state_server, tls_verify_certificates, + NULL, &dummy_errstr) != OK) + return lifetime; + state_server.lib_state.cabundle = TRUE; + + /* If CAs loaded and tls_crl is non-empty and has no $, load it */ + + if (opt_set_and_noexpand(tls_crl)) + { + if (tls_set_watch(tls_crl, FALSE)) + { + DEBUG(D_tls) debug_printf("TLS: preloading CRL for server\n"); + if (creds_load_crl(&state_server, tls_crl, &dummy_errstr) != OK) + return lifetime; + state_server.lib_state.crl = TRUE; } + } + else + DEBUG(D_tls) debug_printf("TLS: not preloading CRL for server\n"); } - else + } +else + DEBUG(D_tls) debug_printf("TLS: not preloading CA bundle for server\n"); +#endif /* EXIM_HAVE_INOTIFY */ + +/* If tls_require_ciphers is non-empty and has no $, load the +ciphers priority cache. If unset, load with the default. +(server-only as the client one depends on non/DANE) */ + +if (!tls_require_ciphers || opt_set_and_noexpand(tls_require_ciphers)) + { + const char * dummy_errpos; + DEBUG(D_tls) debug_printf("TLS: preloading cipher list for server: %s\n", + tls_require_ciphers); + if ( creds_load_pristring(&state_server, tls_require_ciphers, &dummy_errpos) + == OK) + state_server.lib_state.pri_string = TRUE; + } +else + DEBUG(D_tls) debug_printf("TLS: not preloading cipher list for server\n"); +return lifetime; +} + + +/* Preload whatever creds are static, onto a transport. The client can then +just copy the pointer as it starts up. */ + +static void +tls_client_creds_init(transport_instance * t, BOOL watch) +{ +smtp_transport_options_block * ob = t->options_block; +exim_gnutls_state_st tpt_dummy_state; +host_item * dummy_host = (host_item *)1; +uschar * dummy_errstr; + +if ( !exim_gnutls_base_init_done + && tls_g_init(&dummy_errstr) != OK) + return; + +ob->tls_preload = null_tls_preload; +if (gnutls_certificate_allocate_credentials( + (struct gnutls_certificate_credentials_st **)&ob->tls_preload.x509_cred)) + { + ob->tls_preload.x509_cred = NULL; + return; + } +creds_basic_init(ob->tls_preload.x509_cred, FALSE); + +tpt_dummy_state.session = NULL; +tpt_dummy_state.lib_state = ob->tls_preload; + +#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT) +if ( opt_set_and_noexpand(ob->tls_certificate) + && opt_unset_or_noexpand(ob->tls_privatekey)) + { + if ( !watch + || ( tls_set_watch(ob->tls_certificate, FALSE) + && tls_set_watch(ob->tls_privatekey, FALSE) + ) ) + { + const uschar * pkey = ob->tls_privatekey; + + DEBUG(D_tls) + debug_printf("TLS: preloading client certs for transport '%s'\n", t->name); + + /* The state->lib_state.x509_cred is used for the certs load, and is the sole + structure element used. So we can set up a dummy. The hoat arg only + selects a retcode in case of fail, so any value */ + + if (creds_load_client_certs(&tpt_dummy_state, dummy_host, + ob->tls_certificate, pkey ? pkey : ob->tls_certificate, + &dummy_errstr) == OK) + ob->tls_preload.conn_certs = TRUE; + } + } +else + DEBUG(D_tls) + debug_printf("TLS: not preloading client certs, for transport '%s'\n", t->name); + +/* If tls_verify_certificates is non-empty and has no $, load CAs. +If none was configured and we can't handle "system", treat as empty. */ + +if ( opt_set_and_noexpand(ob->tls_verify_certificates) +#ifndef SUPPORT_SYSDEFAULT_CABUNDLE + && Ustrcmp(ob->tls_verify_certificates, "system") != 0 +#endif + ) + { + if (!watch || tls_set_watch(ob->tls_verify_certificates, FALSE)) { - if (0 < (rc = tls_add_certfile(state, host, - state->exp_tls_certificate, state->exp_tls_privatekey, errstr))) - return rc; - DEBUG(D_tls) debug_printf("TLS: cert/key registered\n"); + DEBUG(D_tls) + debug_printf("TLS: preloading CA bundle for transport '%s'\n", t->name); + if (creds_load_cabundle(&tpt_dummy_state, ob->tls_verify_certificates, + dummy_host, &dummy_errstr) != OK) + return; + ob->tls_preload.cabundle = TRUE; + + if (opt_set_and_noexpand(ob->tls_crl)) + { + if (!watch || tls_set_watch(ob->tls_crl, FALSE)) + { + DEBUG(D_tls) debug_printf("TLS: preloading CRL for transport '%s'\n", t->name); + if (creds_load_crl(&tpt_dummy_state, ob->tls_crl, &dummy_errstr) != OK) + return; + ob->tls_preload.crl = TRUE; + } + } + else + DEBUG(D_tls) debug_printf("TLS: not preloading CRL, for transport '%s'\n", t->name); } + } +else + DEBUG(D_tls) + debug_printf("TLS: not preloading CA bundle, for transport '%s'\n", t->name); + +/* We do not preload tls_require_ciphers to to the transport as it implicitly +depends on DANE or plain usage. */ + +#endif +} + + +#if defined(EXIM_HAVE_INOTIFY) || defined(EXIM_HAVE_KEVENT) +/* Invalidate the creds cached, by dropping the current ones. +Call when we notice one of the source files has changed. */ + +static void +tls_server_creds_invalidate(void) +{ +if (state_server.lib_state.pri_cache) + gnutls_priority_deinit(state_server.lib_state.pri_cache); +state_server.lib_state.pri_cache = NULL; + +if (state_server.lib_state.x509_cred) + gnutls_certificate_free_credentials(state_server.lib_state.x509_cred); +state_server.lib_state = null_tls_preload; +} + + +static void +tls_client_creds_invalidate(transport_instance * t) +{ +smtp_transport_options_block * ob = t->options_block; +if (ob->tls_preload.x509_cred) + gnutls_certificate_free_credentials(ob->tls_preload.x509_cred); +ob->tls_preload = null_tls_preload; +} +#endif + + +/************************************************* +* Variables re-expanded post-SNI * +*************************************************/ + +/* Called from both server and client code, via tls_init(), and also from +the SNI callback after receiving an SNI, if tls_certificate includes "tls_sni". + +We can tell the two apart by state->received_sni being non-NULL in callback. + +The callback should not call us unless state->trigger_sni_changes is true, +which we are responsible for setting on the first pass through. + +Arguments: + state exim_gnutls_state_st * + errstr error string pointer + +Returns: OK/DEFER/FAIL +*/ + +static int +tls_expand_session_files(exim_gnutls_state_st * state, uschar ** errstr) +{ +int rc; +const host_item *host = state->host; /* macro should be reconsidered? */ +const uschar *saved_tls_certificate = NULL; +const uschar *saved_tls_privatekey = NULL; +const uschar *saved_tls_verify_certificates = NULL; +const uschar *saved_tls_crl = NULL; +int cert_count; + +/* We check for tls_sni *before* expansion. */ +if (!host) /* server */ + if (!state->received_sni) + { + if ( state->tls_certificate + && ( Ustrstr(state->tls_certificate, US"tls_sni") + || Ustrstr(state->tls_certificate, US"tls_in_sni") + || Ustrstr(state->tls_certificate, US"tls_out_sni") + ) ) + { + DEBUG(D_tls) debug_printf("We will re-expand TLS session files if we receive SNI\n"); + state->trigger_sni_changes = TRUE; + } + } + else /* SNI callback case */ + { + /* useful for debugging */ + saved_tls_certificate = state->exp_tls_certificate; + saved_tls_privatekey = state->exp_tls_privatekey; + saved_tls_verify_certificates = state->exp_tls_verify_certificates; + saved_tls_crl = state->exp_tls_crl; + } + +if (!state->lib_state.x509_cred) + { + if ((rc = gnutls_certificate_allocate_credentials( + (gnutls_certificate_credentials_t *) &state->lib_state.x509_cred))) + return tls_error_gnu(state, US"gnutls_certificate_allocate_credentials", + rc, errstr); + creds_basic_init(state->lib_state.x509_cred, !host); + } + + +/* remember: Expand_check_tlsvar() is expand_check() but fiddling with +state members, assuming consistent naming; and expand_check() returns +false if expansion failed, unless expansion was forced to fail. */ + +/* check if we at least have a certificate, before doing expensive +D-H generation. */ + +if (!state->lib_state.conn_certs) + { + if (!Expand_check_tlsvar(tls_certificate, errstr)) + return DEFER; + + /* certificate is mandatory in server, optional in client */ + + if ( !state->exp_tls_certificate + || !*state->exp_tls_certificate + ) + if (!host) + return tls_install_selfsign(state, errstr); + else + DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n"); + + if (state->tls_privatekey && !Expand_check_tlsvar(tls_privatekey, errstr)) + return DEFER; + + /* tls_privatekey is optional, defaulting to same file as certificate */ + + if (!state->tls_privatekey || !*state->tls_privatekey) + { + state->tls_privatekey = state->tls_certificate; + state->exp_tls_privatekey = state->exp_tls_certificate; + } + + if (state->exp_tls_certificate && *state->exp_tls_certificate) + { + BOOL load = TRUE; + DEBUG(D_tls) debug_printf("certificate file = %s\nkey file = %s\n", + state->exp_tls_certificate, state->exp_tls_privatekey); + + if (state->received_sni) + if ( Ustrcmp(state->exp_tls_certificate, saved_tls_certificate) == 0 + && Ustrcmp(state->exp_tls_privatekey, saved_tls_privatekey) == 0 + ) + { + DEBUG(D_tls) debug_printf("TLS SNI: cert and key unchanged\n"); + load = FALSE; /* avoid re-loading the same certs */ + } + else /* unload the pre-SNI certs before loading new ones */ + { + DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair\n"); + gnutls_certificate_free_keys(state->lib_state.x509_cred); + } + + if ( load + && (rc = host + ? creds_load_client_certs(state, host, state->exp_tls_certificate, + state->exp_tls_privatekey, errstr) + : creds_load_server_certs(state, state->exp_tls_certificate, + state->exp_tls_privatekey, +#ifdef DISABLE_OCSP + NULL, +#else + tls_ocsp_file, +#endif + errstr) + ) ) return rc; + } + } +else + { + DEBUG(D_tls) + debug_printf("%s certs were preloaded\n", host ? "client" : "server"); + + if (!state->tls_privatekey) state->tls_privatekey = state->tls_certificate; + state->exp_tls_certificate = US state->tls_certificate; + state->exp_tls_privatekey = US state->tls_privatekey; - } /* tls_certificate */ +#ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE + if (state->lib_state.ocsp_hook) + gnutls_handshake_set_hook_function(state->session, + GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb); +#endif + } /* Set the trusted CAs file if one is provided, and then add the CRL if one is provided. Experiment shows that, if the certificate file is empty, an unhelpful error message is provided. However, if we just refrain from setting anything up in that case, certificate verification fails, which seems to be the correct -behaviour. */ +behaviour. +If none was configured and we can't handle "system", treat as empty. */ -if (state->tls_verify_certificates && *state->tls_verify_certificates) +if (!state->lib_state.cabundle) { - if (!expand_check_tlsvar(tls_verify_certificates, errstr)) - return DEFER; + if (state->tls_verify_certificates && *state->tls_verify_certificates) + { + if (!Expand_check_tlsvar(tls_verify_certificates, errstr)) + return DEFER; #ifndef SUPPORT_SYSDEFAULT_CABUNDLE - if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) - state->exp_tls_verify_certificates = NULL; + if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) + state->exp_tls_verify_certificates = NULL; #endif - if (state->tls_crl && *state->tls_crl) - if (!expand_check_tlsvar(tls_crl, errstr)) - return DEFER; + if (state->tls_crl && *state->tls_crl) + if (!Expand_check_tlsvar(tls_crl, errstr)) + return DEFER; - if (!(state->exp_tls_verify_certificates && - *state->exp_tls_verify_certificates)) + if (!(state->exp_tls_verify_certificates && + *state->exp_tls_verify_certificates)) + { + DEBUG(D_tls) + debug_printf("TLS: tls_verify_certificates expanded empty, ignoring\n"); + /* With no tls_verify_certificates, we ignore tls_crl too */ + return OK; + } + } + else { DEBUG(D_tls) - debug_printf("TLS: tls_verify_certificates expanded empty, ignoring\n"); - /* With no tls_verify_certificates, we ignore tls_crl too */ + debug_printf("TLS: tls_verify_certificates not set or empty, ignoring\n"); return OK; } + rc = creds_load_cabundle(state, state->exp_tls_verify_certificates, host, errstr); + if (rc != OK) return rc; } else { DEBUG(D_tls) - debug_printf("TLS: tls_verify_certificates not set or empty, ignoring\n"); - return OK; - } - -#ifdef SUPPORT_SYSDEFAULT_CABUNDLE -if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) - cert_count = gnutls_certificate_set_x509_system_trust(state->x509_cred); -else -#endif - { - if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0) - { - log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s " - "(tls_verify_certificates): %s", state->exp_tls_verify_certificates, - strerror(errno)); - return DEFER; - } - -#ifndef SUPPORT_CA_DIR - /* The test suite passes in /dev/null; we could check for that path explicitly, - but who knows if someone has some weird FIFO which always dumps some certs, or - other weirdness. The thing we really want to check is that it's not a - directory, since while OpenSSL supports that, GnuTLS does not. - So s/!S_ISREG/S_ISDIR/ and change some messaging ... */ - if (S_ISDIR(statbuf.st_mode)) - { - DEBUG(D_tls) - debug_printf("verify certificates path is a dir: \"%s\"\n", - state->exp_tls_verify_certificates); - log_write(0, LOG_MAIN|LOG_PANIC, - "tls_verify_certificates \"%s\" is a directory", - state->exp_tls_verify_certificates); - return DEFER; - } -#endif - - DEBUG(D_tls) debug_printf("verify certificates = %s size=" OFF_T_FMT "\n", - state->exp_tls_verify_certificates, statbuf.st_size); - - if (statbuf.st_size == 0) - { - DEBUG(D_tls) - debug_printf("cert file empty, no certs, no verification, ignoring any CRL\n"); - return OK; - } - - cert_count = + debug_printf("%s CA bundle was preloaded\n", host ? "client" : "server"); + state->exp_tls_verify_certificates = US state->tls_verify_certificates; #ifdef SUPPORT_CA_DIR - (statbuf.st_mode & S_IFMT) == S_IFDIR - ? - gnutls_certificate_set_x509_trust_dir(state->x509_cred, - CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM) - : +/* Mimic the behaviour with OpenSSL of not advertising a usable-cert list +when using the directory-of-certs config model. */ + if (state->lib_state.ca_rdn_emulate) + gnutls_certificate_send_x509_rdn_sequence(state->session, 1); #endif - gnutls_certificate_set_x509_trust_file(state->x509_cred, - CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM); } -if (cert_count < 0) + +if (!state->lib_state.crl) { - rc = cert_count; - exim_gnutls_err_check(rc, US"setting certificate trust"); + if ( state->tls_crl && *state->tls_crl + && state->exp_tls_crl && *state->exp_tls_crl) + return creds_load_crl(state, state->exp_tls_crl, errstr); } -DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", cert_count); - -if (state->tls_crl && *state->tls_crl && - state->exp_tls_crl && *state->exp_tls_crl) +else { - DEBUG(D_tls) debug_printf("loading CRL file = %s\n", state->exp_tls_crl); - cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred, - CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM); - if (cert_count < 0) - { - rc = cert_count; - exim_gnutls_err_check(rc, US"gnutls_certificate_set_x509_crl_file"); - } - DEBUG(D_tls) debug_printf("Processed %d CRLs.\n", cert_count); + DEBUG(D_tls) + debug_printf("%s CRL was preloaded\n", host ? "client" : "server"); + state->exp_tls_crl = US state->tls_crl; } return OK; @@ -1192,17 +1957,18 @@ client-side params. */ if (!state->host) { if (!dh_server_params) - { - rc = init_server_dh(errstr); - if (rc != OK) return rc; - } - gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params); + if ((rc = init_server_dh(errstr)) != OK) return rc; + + /* Unnecessary & discouraged with 3.6.0 or later, according to docs. But without it, + no DHE- ciphers are advertised. */ + gnutls_certificate_set_dh_params(state->lib_state.x509_cred, dh_server_params); } /* Link the credentials to the session. */ -rc = gnutls_credentials_set(state->session, GNUTLS_CRD_CERTIFICATE, state->x509_cred); -exim_gnutls_err_check(rc, US"gnutls_credentials_set"); +if ((rc = gnutls_credentials_set(state->session, + GNUTLS_CRD_CERTIFICATE, state->lib_state.x509_cred))) + return tls_error_gnu(state, US"gnutls_credentials_set", rc, errstr); return OK; } @@ -1212,47 +1978,12 @@ return OK; *************************************************/ -#ifndef DISABLE_OCSP - -static BOOL -tls_is_buggy_ocsp(void) -{ -const uschar * s; -uschar maj, mid, mic; - -s = CUS gnutls_check_version(NULL); -maj = atoi(CCS s); -if (maj == 3) - { - while (*s && *s != '.') s++; - mid = atoi(CCS ++s); - if (mid <= 2) - return TRUE; - else if (mid >= 5) - return FALSE; - else - { - while (*s && *s != '.') s++; - mic = atoi(CCS ++s); - return mic <= (mid == 3 ? 16 : 3); - } - } -return FALSE; -} - -#endif - - /* Called from both server and client code. In the case of a server, errors before actual TLS negotiation return DEFER. Arguments: host connected host, if client; NULL if server - certificate certificate file - privatekey private key file - sni TLS SNI to send, sometimes when client; else NULL - cas CA certs file - crl CRL file + ob tranport options block, if client; NULL if server require_ciphers tls_require_ciphers setting caller_state returned state-info structure errstr error string pointer @@ -1263,98 +1994,70 @@ Returns: OK/DEFER/FAIL static int tls_init( const host_item *host, - const uschar *certificate, - const uschar *privatekey, - const uschar *sni, - const uschar *cas, - const uschar *crl, - const uschar *require_ciphers, + smtp_transport_options_block * ob, + const uschar * require_ciphers, exim_gnutls_state_st **caller_state, tls_support * tlsp, uschar ** errstr) { -exim_gnutls_state_st *state; +exim_gnutls_state_st * state; int rc; size_t sz; -const char *errpos; -uschar *p; -BOOL want_default_priorities; - -if (!exim_gnutls_base_init_done) - { - DEBUG(D_tls) debug_printf("GnuTLS global init required.\n"); - -#ifdef HAVE_GNUTLS_PKCS11 - /* By default, gnutls_global_init will init PKCS11 support in auto mode, - which loads modules from a config file, which sounds good and may be wanted - by some sysadmin, but also means in common configurations that GNOME keyring - environment variables are used and so breaks for users calling mailq. - To prevent this, we init PKCS11 first, which is the documented approach. */ - if (!gnutls_allow_auto_pkcs11) - { - rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL); - exim_gnutls_err_check(rc, US"gnutls_pkcs11_init"); - } -#endif - - rc = gnutls_global_init(); - exim_gnutls_err_check(rc, US"gnutls_global_init"); - -#if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 - DEBUG(D_tls) - { - gnutls_global_set_log_function(exim_gnutls_logger_cb); - /* arbitrarily chosen level; bump upto 9 for more */ - gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL); - } -#endif - -#ifndef DISABLE_OCSP - if (tls_ocsp_file && (gnutls_buggy_ocsp = tls_is_buggy_ocsp())) - log_write(0, LOG_MAIN, "OCSP unusable with this GnuTLS library version"); -#endif - exim_gnutls_base_init_done = TRUE; - } +if ( !exim_gnutls_base_init_done + && (rc = tls_g_init(errstr)) != OK) + return rc; if (host) { /* For client-side sessions we allocate a context. This lets us run several in parallel. */ + int old_pool = store_pool; store_pool = POOL_PERM; - state = store_get(sizeof(exim_gnutls_state_st)); + state = store_get(sizeof(exim_gnutls_state_st), FALSE); store_pool = old_pool; memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); + state->lib_state = ob->tls_preload; state->tlsp = tlsp; DEBUG(D_tls) debug_printf("initialising GnuTLS client session\n"); rc = gnutls_init(&state->session, GNUTLS_CLIENT); + + state->tls_certificate = ob->tls_certificate; + state->tls_privatekey = ob->tls_privatekey; + state->tls_sni = ob->tls_sni; + state->tls_verify_certificates = ob->tls_verify_certificates; + state->tls_crl = ob->tls_crl; } else { + /* Server operations always use the one state_server context. It is not + shared because we have forked a fresh process for every receive. However it + can get re-used for successive TLS sessions on a single TCP connection. */ + state = &state_server; - memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); state->tlsp = tlsp; DEBUG(D_tls) debug_printf("initialising GnuTLS server session\n"); rc = gnutls_init(&state->session, GNUTLS_SERVER); + + state->tls_certificate = tls_certificate; + state->tls_privatekey = tls_privatekey; + state->tls_sni = NULL; + state->tls_verify_certificates = tls_verify_certificates; + state->tls_crl = tls_crl; } -exim_gnutls_err_check(rc, US"gnutls_init"); +if (rc) + return tls_error_gnu(state, US"gnutls_init", rc, errstr); +state->tls_require_ciphers = require_ciphers; state->host = host; -state->tls_certificate = certificate; -state->tls_privatekey = privatekey; -state->tls_require_ciphers = require_ciphers; -state->tls_sni = sni; -state->tls_verify_certificates = cas; -state->tls_crl = crl; - /* This handles the variables that might get re-expanded after TLS SNI; -that's tls_certificate, tls_privatekey, tls_verify_certificates, tls_crl */ +tls_certificate, tls_privatekey, tls_verify_certificates, tls_crl */ DEBUG(D_tls) - debug_printf("Expanding various TLS configuration options for session credentials.\n"); + debug_printf("Expanding various TLS configuration options for session credentials\n"); if ((rc = tls_expand_session_files(state, errstr)) != OK) return rc; /* These are all other parts of the x509_cred handling, since SNI in GnuTLS @@ -1365,61 +2068,62 @@ if ((rc = tls_set_remaining_x509(state, errstr)) != OK) return rc; /* set SNI in client, only */ if (host) { - if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni, errstr)) + if (!expand_check(state->tls_sni, US"tls_out_sni", &state->tlsp->sni, errstr)) return DEFER; if (state->tlsp->sni && *state->tlsp->sni) { DEBUG(D_tls) debug_printf("Setting TLS client SNI to \"%s\"\n", state->tlsp->sni); sz = Ustrlen(state->tlsp->sni); - rc = gnutls_server_name_set(state->session, - GNUTLS_NAME_DNS, state->tlsp->sni, sz); - exim_gnutls_err_check(rc, US"gnutls_server_name_set"); + if ((rc = gnutls_server_name_set(state->session, + GNUTLS_NAME_DNS, state->tlsp->sni, sz))) + return tls_error_gnu(state, US"gnutls_server_name_set", rc, errstr); } } else if (state->tls_sni) DEBUG(D_tls) debug_printf("*** PROBABLY A BUG *** " \ "have an SNI set for a server [%s]\n", state->tls_sni); -/* This is the priority string support, -http://www.gnutls.org/manual/html_node/Priority-Strings.html -and replaces gnutls_require_kx, gnutls_require_mac & gnutls_require_protocols. -This was backwards incompatible, but means Exim no longer needs to track -all algorithms and provide string forms for them. */ +if (!state->lib_state.pri_string) + { + const uschar * p = NULL; + const char * errpos; -want_default_priorities = TRUE; + /* This is the priority string support, + http://www.gnutls.org/manual/html_node/Priority-Strings.html + and replaces gnutls_require_kx, gnutls_require_mac & gnutls_require_protocols. + This was backwards incompatible, but means Exim no longer needs to track + all algorithms and provide string forms for them. */ -if (state->tls_require_ciphers && *state->tls_require_ciphers) - { - if (!expand_check_tlsvar(tls_require_ciphers, errstr)) - return DEFER; - if (state->exp_tls_require_ciphers && *state->exp_tls_require_ciphers) + if (state->tls_require_ciphers && *state->tls_require_ciphers) { - DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n", - state->exp_tls_require_ciphers); - - rc = gnutls_priority_init(&state->priority_cache, - CS state->exp_tls_require_ciphers, &errpos); - want_default_priorities = FALSE; - p = state->exp_tls_require_ciphers; + if (!Expand_check_tlsvar(tls_require_ciphers, errstr)) + return DEFER; + if (state->exp_tls_require_ciphers && *state->exp_tls_require_ciphers) + { + p = state->exp_tls_require_ciphers; + DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n", p); + } } + + if ((rc = creds_load_pristring(state, p, &errpos))) + return tls_error_gnu(state, string_sprintf( + "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"", + p, (long)(errpos - CS p), errpos), + rc, errstr); } -if (want_default_priorities) +else { - DEBUG(D_tls) - debug_printf("GnuTLS using default session cipher/priority \"%s\"\n", - exim_default_gnutls_priority); - rc = gnutls_priority_init(&state->priority_cache, - exim_default_gnutls_priority, &errpos); - p = US exim_default_gnutls_priority; + DEBUG(D_tls) debug_printf("cipher list preloaded\n"); + state->exp_tls_require_ciphers = US state->tls_require_ciphers; } -exim_gnutls_err_check(rc, string_sprintf( - "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"", - p, errpos - CS p, errpos)); -rc = gnutls_priority_set(state->session, state->priority_cache); -exim_gnutls_err_check(rc, US"gnutls_priority_set"); +if ((rc = gnutls_priority_set(state->session, state->lib_state.pri_cache))) + return tls_error_gnu(state, US"gnutls_priority_set", rc, errstr); + +/* This also sets the server ticket expiration time to the same, and +the STEK rotation time to 3x. */ gnutls_db_set_cache_expiration(state->session, ssl_session_timeout); @@ -1445,6 +2149,25 @@ return OK; * Extract peer information * *************************************************/ +static const uschar * +cipher_stdname_kcm(gnutls_kx_algorithm_t kx, gnutls_cipher_algorithm_t cipher, + gnutls_mac_algorithm_t mac) +{ +uschar cs_id[2]; +gnutls_kx_algorithm_t kx_i; +gnutls_cipher_algorithm_t cipher_i; +gnutls_mac_algorithm_t mac_i; + +for (size_t i = 0; + gnutls_cipher_suite_info(i, cs_id, &kx_i, &cipher_i, &mac_i, NULL); + i++) + if (kx_i == kx && cipher_i == cipher && mac_i == mac) + return cipher_stdname(cs_id[0], cs_id[1]); +return NULL; +} + + + /* Called from both server and client code. Only this is allowed to set state->peerdn and state->have_set_peerdn and we use that to detect double-calls. @@ -1471,10 +2194,10 @@ Returns: OK/DEFER/FAIL */ static int -peer_status(exim_gnutls_state_st *state, uschar ** errstr) +peer_status(exim_gnutls_state_st * state, uschar ** errstr) { -uschar cipherbuf[256]; -const gnutls_datum_t *cert_list; +gnutls_session_t session = state->session; +const gnutls_datum_t * cert_list; int old_pool, rc; unsigned int cert_list_size = 0; gnutls_protocol_t protocol; @@ -1483,7 +2206,7 @@ gnutls_kx_algorithm_t kx; gnutls_mac_algorithm_t mac; gnutls_certificate_type_t ct; gnutls_x509_crt_t crt; -uschar *dn_buf; +uschar * dn_buf; size_t sz; if (state->have_set_peerdn) @@ -1493,33 +2216,81 @@ state->have_set_peerdn = TRUE; state->peerdn = NULL; /* tls_cipher */ -cipher = gnutls_cipher_get(state->session); -protocol = gnutls_protocol_get_version(state->session); -mac = gnutls_mac_get(state->session); -kx = gnutls_kx_get(state->session); - -string_format(cipherbuf, sizeof(cipherbuf), - "%s:%s:%d", - gnutls_protocol_get_name(protocol), - gnutls_cipher_suite_get_name(kx, cipher, mac), - (int) gnutls_cipher_get_key_size(cipher) * 8); - -/* I don't see a way that spaces could occur, in the current GnuTLS -code base, but it was a concern in the old code and perhaps older GnuTLS -releases did return "TLS 1.0"; play it safe, just in case. */ -for (uschar * p = cipherbuf; *p != '\0'; ++p) - if (isspace(*p)) - *p = '-'; +cipher = gnutls_cipher_get(session); +protocol = gnutls_protocol_get_version(session); +mac = gnutls_mac_get(session); +kx = +#ifdef GNUTLS_TLS1_3 + protocol >= GNUTLS_TLS1_3 ? 0 : +#endif + gnutls_kx_get(session); + old_pool = store_pool; -store_pool = POOL_PERM; -state->ciphersuite = string_copy(cipherbuf); + { + tls_support * tlsp = state->tlsp; + store_pool = POOL_PERM; + +#ifdef SUPPORT_GNUTLS_SESS_DESC + { + gstring * g = NULL; + uschar * s = US gnutls_session_get_desc(session), c; + + /* Nikos M suggests we use this by preference. It returns like: + (TLS1.3)-(ECDHE-SECP256R1)-(RSA-PSS-RSAE-SHA256)-(AES-256-GCM) + + For partial back-compat, put a colon after the TLS version, replace the + )-( grouping with __, replace in-group - with _ and append the :keysize. */ + + /* debug_printf("peer_status: gnutls_session_get_desc %s\n", s); */ + + for (s++; (c = *s) && c != ')'; s++) g = string_catn(g, s, 1); + + tlsp->ver = string_copyn(g->s, g->ptr); + for (uschar * p = US tlsp->ver; *p; p++) + if (*p == '-') { *p = '\0'; break; } /* TLS1.0-PKIX -> TLS1.0 */ + + g = string_catn(g, US":", 1); + if (*s) s++; /* now on _ between groups */ + while ((c = *s)) + { + for (*++s && ++s; (c = *s) && c != ')'; s++) + g = string_catn(g, c == '-' ? US"_" : s, 1); + /* now on ) closing group */ + if ((c = *s) && *++s == '-') g = string_catn(g, US"__", 2); + /* now on _ between groups */ + } + g = string_catn(g, US":", 1); + g = string_cat(g, string_sprintf("%d", (int) gnutls_cipher_get_key_size(cipher) * 8)); + state->ciphersuite = string_from_gstring(g); + } +#else + state->ciphersuite = string_sprintf("%s:%s:%d", + gnutls_protocol_get_name(protocol), + gnutls_cipher_suite_get_name(kx, cipher, mac), + (int) gnutls_cipher_get_key_size(cipher) * 8); + + /* I don't see a way that spaces could occur, in the current GnuTLS + code base, but it was a concern in the old code and perhaps older GnuTLS + releases did return "TLS 1.0"; play it safe, just in case. */ + + for (uschar * p = state->ciphersuite; *p; p++) if (isspace(*p)) *p = '-'; + tlsp->ver = string_copyn(state->ciphersuite, + Ustrchr(state->ciphersuite, ':') - state->ciphersuite); +#endif + +/* debug_printf("peer_status: ciphersuite %s\n", state->ciphersuite); */ + + tlsp->cipher = state->ciphersuite; + tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; + + tlsp->cipher_stdname = cipher_stdname_kcm(kx, cipher, mac); + } store_pool = old_pool; -state->tlsp->cipher = state->ciphersuite; /* tls_peerdn */ -cert_list = gnutls_certificate_get_peers(state->session, &cert_list_size); +cert_list = gnutls_certificate_get_peers(session, &cert_list_size); -if (cert_list == NULL || cert_list_size == 0) +if (!cert_list || cert_list_size == 0) { DEBUG(D_tls) debug_printf("TLS: no certificate from peer (%p & %d)\n", cert_list, cert_list_size); @@ -1529,10 +2300,9 @@ if (cert_list == NULL || cert_list_size == 0) return OK; } -ct = gnutls_certificate_type_get(state->session); -if (ct != GNUTLS_CRT_X509) +if ((ct = gnutls_certificate_type_get(session)) != GNUTLS_CRT_X509) { - const uschar *ctn = US gnutls_certificate_type_get_name(ct); + const uschar * ctn = US gnutls_certificate_type_get_name(ct); DEBUG(D_tls) debug_printf("TLS: peer cert not X.509 but instead \"%s\"\n", ctn); if (state->verify_requirement >= VERIFY_REQUIRED) @@ -1548,7 +2318,7 @@ if (ct != GNUTLS_CRT_X509) DEBUG(D_tls) debug_printf("TLS: peer cert problem: %s: %s\n", \ (Label), gnutls_strerror(rc)); \ if (state->verify_requirement >= VERIFY_REQUIRED) \ - return tls_error((Label), US gnutls_strerror(rc), state->host, errstr); \ + return tls_error_gnu(state, (Label), rc, errstr); \ return OK; \ } \ } while (0) @@ -1565,7 +2335,7 @@ if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) exim_gnutls_peer_err(US"getting size for cert DN failed"); return FAIL; /* should not happen */ } -dn_buf = store_get_perm(sz); +dn_buf = store_get_perm(sz, TRUE); /* tainted */ rc = gnutls_x509_crt_get_dn(crt, CS dn_buf, &sz); exim_gnutls_peer_err(US"failed to extract certificate DN [gnutls_x509_crt_get_dn(cert 0)]"); @@ -1602,13 +2372,14 @@ verify_certificate(exim_gnutls_state_st * state, uschar ** errstr) int rc; uint verify; -if (state->verify_requirement == VERIFY_NONE) - return TRUE; - DEBUG(D_tls) debug_printf("TLS: checking peer certificate\n"); *errstr = NULL; +rc = peer_status(state, errstr); -if ((rc = peer_status(state, errstr)) != OK) +if (state->verify_requirement == VERIFY_NONE) + return TRUE; + +if (rc != OK || !state->peerdn) { verify = GNUTLS_CERT_INVALID; *errstr = US"certificate not supplied"; @@ -1641,11 +2412,11 @@ else const char ** dd; int * ddl; - for(nrec = 0; state->dane_data_len[nrec]; ) nrec++; + for (nrec = 0; state->dane_data_len[nrec]; ) nrec++; nrec++; - dd = store_get(nrec * sizeof(uschar *)); - ddl = store_get(nrec * sizeof(int)); + dd = store_get(nrec * sizeof(uschar *), FALSE); + ddl = store_get(nrec * sizeof(int), FALSE); nrec--; if ((rc = dane_state_init(&s, 0))) @@ -1873,13 +2644,12 @@ uschar * dummy_errstr; rc = gnutls_server_name_get(session, sni_name, &data_len, &sni_type, 0); if (rc != GNUTLS_E_SUCCESS) { - DEBUG(D_tls) { + DEBUG(D_tls) if (rc == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) - debug_printf("TLS: no SNI presented in handshake.\n"); + debug_printf("TLS: no SNI presented in handshake\n"); else debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n", gnutls_strerror(rc), rc); - } return 0; } @@ -1892,7 +2662,7 @@ if (sni_type != GNUTLS_NAME_DNS) /* We now have a UTF-8 string in sni_name */ old_pool = store_pool; store_pool = POOL_PERM; -state->received_sni = string_copyn(US sni_name, data_len); +state->received_sni = string_copy_taint(US sni_name, TRUE); store_pool = old_pool; /* We set this one now so that variable expansions below will work */ @@ -1919,78 +2689,222 @@ return 0; -#ifndef DISABLE_OCSP +#ifndef DISABLE_EVENT +/* +We use this callback to get observability and detail-level control +for an exim TLS connection (either direction), raising a tls:cert event +for each cert in the chain presented by the peer. Any event +can deny verification. + +Return 0 for the handshake to continue or non-zero to terminate. +*/ static int -server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, - gnutls_datum_t * ocsp_response) +verify_cb(gnutls_session_t session) { -int ret; -DEBUG(D_tls) debug_printf("OCSP stapling callback: %s\n", US ptr); +const gnutls_datum_t * cert_list; +unsigned int cert_list_size = 0; +gnutls_x509_crt_t crt; +int rc; +uschar * yield; +exim_gnutls_state_st * state = gnutls_session_get_ptr(session); -if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0) +if ((cert_list = gnutls_certificate_get_peers(session, &cert_list_size))) + while (cert_list_size--) { - DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n", - CS ptr); - tls_in.ocsp = OCSP_NOT_RESP; - return GNUTLS_E_NO_CERTIFICATE_STATUS; + if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS) + { + DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n", + cert_list_size, gnutls_strerror(rc)); + break; + } + + state->tlsp->peercert = crt; + if ((yield = event_raise(state->event_action, + US"tls:cert", string_sprintf("%d", cert_list_size)))) + { + log_write(0, LOG_MAIN, + "SSL verify denied by event-action: depth=%d: %s", + cert_list_size, yield); + return 1; /* reject */ + } + state->tlsp->peercert = NULL; + } + +return 0; +} + +#endif + + +static gstring * +ddump(gnutls_datum_t * d) +{ +gstring * g = string_get((d->size+1) * 2); +uschar * s = d->data; +for (unsigned i = d->size; i > 0; i--, s++) + { + g = string_catn(g, US "0123456789abcdef" + (*s >> 4), 1); + g = string_catn(g, US "0123456789abcdef" + (*s & 0xf), 1); + } +return g; +} + +static void +post_handshake_debug(exim_gnutls_state_st * state) +{ +#ifdef SUPPORT_GNUTLS_SESS_DESC +debug_printf("%s\n", gnutls_session_get_desc(state->session)); +#endif + +#ifdef SUPPORT_GNUTLS_KEYLOG +# ifdef EXIM_HAVE_TLS1_3 +if (gnutls_protocol_get_version(state->session) < GNUTLS_TLS1_3) +# else +if (TRUE) +# endif + { + gnutls_datum_t c, s; + gstring * gc, * gs; + /* For TLS1.2 we only want the client random and the master secret */ + gnutls_session_get_random(state->session, &c, &s); + gnutls_session_get_master_secret(state->session, &s); + gc = ddump(&c); + gs = ddump(&s); + debug_printf("CLIENT_RANDOM %.*s %.*s\n", (int)gc->ptr, gc->s, (int)gs->ptr, gs->s); + } +else + debug_printf("To get keying info for TLS1.3 is hard:\n" + " Set environment variable SSLKEYLOGFILE to a filename relative to the spool directory,\n" + " and make sure it is writable by the Exim runtime user.\n" + " Add SSLKEYLOGFILE to keep_environment in the exim config.\n" + " Start Exim as root.\n" + " If using sudo, add SSLKEYLOGFILE to env_keep in /etc/sudoers\n" + " (works for TLS1.2 also, and saves cut-paste into file).\n" + " Trying to use add_environment for this will not work\n"); +#endif +} + + +#ifdef EXIM_HAVE_TLS_RESUME +static int +tls_server_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when, + unsigned incoming, const gnutls_datum_t * msg) +{ +DEBUG(D_tls) debug_printf("newticket cb\n"); +tls_in.resumption |= RESUME_CLIENT_REQUESTED; +return 0; +} + +static void +tls_server_resume_prehandshake(exim_gnutls_state_st * state) +{ +/* Should the server offer session resumption? */ +tls_in.resumption = RESUME_SUPPORTED; +if (verify_check_host(&tls_resumption_hosts) == OK) + { + int rc; + /* GnuTLS appears to not do ticket overlap, but does emit a fresh ticket when + an offered resumption is unacceptable. We lose one resumption per ticket + lifetime, and sessions cannot be indefinitely re-used. There seems to be no + way (3.6.7) of changing the default number of 2 TLS1.3 tickets issued, but at + least they go out in a single packet. */ + + if (!(rc = gnutls_session_ticket_enable_server(state->session, + &server_sessticket_key))) + tls_in.resumption |= RESUME_SERVER_TICKET; + else + DEBUG(D_tls) + debug_printf("enabling session tickets: %s\n", US gnutls_strerror(rc)); + + /* Try to tell if we see a ticket request */ + gnutls_handshake_set_hook_function(state->session, + GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb); + } +} + +static void +tls_server_resume_posthandshake(exim_gnutls_state_st * state) +{ +if (gnutls_session_resumption_requested(state->session)) + { + /* This tells us the client sent a full ticket. We use a + callback on session-ticket request, elsewhere, to tell + if a client asked for a ticket. */ + + tls_in.resumption |= RESUME_CLIENT_SUGGESTED; + DEBUG(D_tls) debug_printf("client requested resumption\n"); + } +if (gnutls_session_is_resumed(state->session)) + { + tls_in.resumption |= RESUME_USED; + DEBUG(D_tls) debug_printf("Session resumed\n"); } - -tls_in.ocsp = OCSP_VFY_NOT_TRIED; -return 0; } +#endif /* EXIM_HAVE_TLS_RESUME */ -#endif - - -#ifndef DISABLE_EVENT -/* -We use this callback to get observability and detail-level control -for an exim TLS connection (either direction), raising a tls:cert event -for each cert in the chain presented by the peer. Any event -can deny verification. -Return 0 for the handshake to continue or non-zero to terminate. +#ifdef EXIM_HAVE_ALPN +/* Expand and convert an Exim list to a gnutls_datum list. False return for fail. +NULL plist return for silent no-ALPN. */ -static int -verify_cb(gnutls_session_t session) +static BOOL +tls_alpn_plist(const uschar * tls_alpn, const gnutls_datum_t ** plist, unsigned * plen, + uschar ** errstr) { -const gnutls_datum_t * cert_list; -unsigned int cert_list_size = 0; -gnutls_x509_crt_t crt; -int rc; -uschar * yield; -exim_gnutls_state_st * state = gnutls_session_get_ptr(session); +uschar * exp_alpn; -if ((cert_list = gnutls_certificate_get_peers(session, &cert_list_size))) - while (cert_list_size--) - { - if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS) - { - DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n", - cert_list_size, gnutls_strerror(rc)); - break; - } +if (!expand_check(tls_alpn, US"tls_alpn", &exp_alpn, errstr)) + return FALSE; - state->tlsp->peercert = crt; - if ((yield = event_raise(state->event_action, - US"tls:cert", string_sprintf("%d", cert_list_size)))) - { - log_write(0, LOG_MAIN, - "SSL verify denied by event-action: depth=%d: %s", - cert_list_size, yield); - return 1; /* reject */ - } - state->tlsp->peercert = NULL; +if (!exp_alpn) + { + DEBUG(D_tls) debug_printf("Setting TLS ALPN forced to fail, not sending\n"); + *plist = NULL; } - -return 0; +else + { + const uschar * list = exp_alpn; + int sep = 0; + unsigned cnt = 0; + gnutls_datum_t * p; + uschar * s; + + while (string_nextinlist(&list, &sep, NULL, 0)) cnt++; + + p = store_get(sizeof(gnutls_datum_t) * cnt, is_tainted(exp_alpn)); + list = exp_alpn; + for (int i = 0; s = string_nextinlist(&list, &sep, NULL, 0); i++) + { p[i].data = s; p[i].size = Ustrlen(s); } + *plist = (*plen = cnt) ? p : NULL; + } +return TRUE; } -#endif - +static void +tls_server_set_acceptable_alpns(exim_gnutls_state_st * state, uschar ** errstr) +{ +int rc; +const gnutls_datum_t * plist; +unsigned plen; +if (tls_alpn_plist(tls_alpn, &plist, &plen, errstr) && plist) + { + /* This seems to be only mandatory if the client sends an ALPN extension; + not trying ALPN is ok. Need to decide how to support server-side must-alpn. */ + + server_seen_alpn = 0; + if (!(rc = gnutls_alpn_set_protocols(state->session, plist, plen, + GNUTLS_ALPN_MANDATORY))) + gnutls_handshake_set_hook_function(state->session, + GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb); + else + DEBUG(D_tls) + debug_printf("setting alpn protocols: %s\n", US gnutls_strerror(rc)); + } +} +#endif /* EXIM_HAVE_ALPN */ /* ------------------------------------------------------------------------ */ /* Exported functions */ @@ -2007,7 +2921,6 @@ the STARTTLS command. It must respond to that command, and then negotiate a TLS session. Arguments: - require_ciphers list of allowed ciphers or NULL errstr pointer to error string Returns: OK on success @@ -2017,7 +2930,7 @@ Returns: OK on success */ int -tls_server_start(const uschar * require_ciphers, uschar ** errstr) +tls_server_start(uschar ** errstr) { int rc; exim_gnutls_state_st * state = NULL; @@ -2035,9 +2948,27 @@ and sent an SMTP response. */ DEBUG(D_tls) debug_printf("initialising GnuTLS as a server\n"); -if ((rc = tls_init(NULL, tls_certificate, tls_privatekey, - NULL, tls_verify_certificates, tls_crl, - require_ciphers, &state, &tls_in, errstr)) != OK) return rc; + { +#ifdef MEASURE_TIMING + struct timeval t0; + gettimeofday(&t0, NULL); +#endif + + if ((rc = tls_init(NULL, NULL, + tls_require_ciphers, &state, &tls_in, errstr)) != OK) return rc; + +#ifdef MEASURE_TIMING + report_time_since(&t0, US"server tls_init (delta)"); +#endif + } + +#ifdef EXIM_HAVE_ALPN +tls_server_set_acceptable_alpns(state, errstr); +#endif + +#ifdef EXIM_HAVE_TLS_RESUME +tls_server_resume_prehandshake(state); +#endif /* If this is a host for which certificate verification is mandatory or optional, set up appropriately. */ @@ -2045,21 +2976,21 @@ optional, set up appropriately. */ if (verify_check_host(&tls_verify_hosts) == OK) { DEBUG(D_tls) - debug_printf("TLS: a client certificate will be required.\n"); + debug_printf("TLS: a client certificate will be required\n"); state->verify_requirement = VERIFY_REQUIRED; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); } else if (verify_check_host(&tls_try_verify_hosts) == OK) { DEBUG(D_tls) - debug_printf("TLS: a client certificate will be requested but not required.\n"); + debug_printf("TLS: a client certificate will be requested but not required\n"); state->verify_requirement = VERIFY_OPTIONAL; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); } else { DEBUG(D_tls) - debug_printf("TLS: a client certificate will not be requested.\n"); + debug_printf("TLS: a client certificate will not be requested\n"); state->verify_requirement = VERIFY_NONE; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); } @@ -2069,7 +3000,7 @@ if (event_action) { state->event_action = event_action; gnutls_session_set_ptr(state->session, state); - gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); + gnutls_certificate_set_verify_function(state->lib_state.x509_cred, verify_cb); } #endif @@ -2123,10 +3054,11 @@ if (rc != GNUTLS_E_SUCCESS) } else { - tls_error(US"gnutls_handshake", US gnutls_strerror(rc), NULL, errstr); + tls_error_gnu(state, US"gnutls_handshake", rc, errstr); (void) gnutls_alert_send_appropriate(state->session, rc); gnutls_deinit(state->session); - gnutls_certificate_free_credentials(state->x509_cred); + gnutls_certificate_free_credentials(state->lib_state.x509_cred); + state->lib_state = null_tls_preload; millisleep(500); shutdown(state->fd_out, SHUT_WR); for (int i = 1024; fgetc(smtp_in) != EOF && i > 0; ) i--; /* drain skt */ @@ -2138,7 +3070,43 @@ if (rc != GNUTLS_E_SUCCESS) return FAIL; } -DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n"); +#ifdef GNUTLS_SFLAGS_EXT_MASTER_SECRET +if (gnutls_session_get_flags(state->session) & GNUTLS_SFLAGS_EXT_MASTER_SECRET) + tls_in.ext_master_secret = TRUE; +#endif + +#ifdef EXIM_HAVE_TLS_RESUME +tls_server_resume_posthandshake(state); +#endif + +DEBUG(D_tls) post_handshake_debug(state); + +#ifdef EXIM_HAVE_ALPN +if (server_seen_alpn > 0) + { + DEBUG(D_tls) + { /* The client offered ALPN. See what was negotiated. */ + gnutls_datum_t p = {.size = 0}; + int rc = gnutls_alpn_get_selected_protocol(state->session, &p); + if (!rc) + debug_printf("ALPN negotiated: %.*s\n", (int)p.size, p.data); + else + debug_printf("getting alpn protocol: %s\n", US gnutls_strerror(rc)); + + } + } +else if (server_seen_alpn == 0) + if (verify_check_host(&hosts_require_alpn) == OK) + { + gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_NO_APPLICATION_PROTOCOL); + tls_error(US"handshake", US"ALPN required but not negotiated", NULL, errstr); + return FAIL; + } + else + DEBUG(D_tls) debug_printf("TLS: no ALPN presented in handshake\n"); +else + DEBUG(D_tls) debug_printf("TLS: was not watching for ALPN\n"); +#endif /* Verify after the fact */ @@ -2154,10 +3122,6 @@ if (!verify_certificate(state, errstr)) *errstr); } -/* Figure out peer DN, and if authenticated, etc. */ - -if ((rc = peer_status(state, NULL)) != OK) return rc; - /* Sets various Exim expansion variables; always safe within server */ extract_exim_vars_from_tls_state(state); @@ -2170,10 +3134,10 @@ state->xfer_buffer = store_malloc(ssl_xfer_buffer_size); receive_getc = tls_getc; receive_getbuf = tls_getbuf; receive_get_cache = tls_get_cache; +receive_hasc = tls_hasc; receive_ungetc = tls_ungetc; receive_feof = tls_feof; receive_ferror = tls_ferror; -receive_smtp_buffered = tls_smtp_buffered; return OK; } @@ -2189,12 +3153,12 @@ if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK) { state->exp_tls_verify_cert_hostnames = #ifdef SUPPORT_I18N - string_domain_utf8_to_alabel(host->name, NULL); + string_domain_utf8_to_alabel(host->certname, NULL); #else - host->name; + host->certname; #endif DEBUG(D_tls) - debug_printf("TLS: server cert verification includes hostname: \"%s\".\n", + debug_printf("TLS: server cert verification includes hostname: \"%s\"\n", state->exp_tls_verify_cert_hostnames); } } @@ -2223,8 +3187,8 @@ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) ) if (rr->type == T_TLSA) i++; -dane_data = store_get(i * sizeof(uschar *)); -dane_data_len = store_get(i * sizeof(int)); +dane_data = store_get(i * sizeof(uschar *), FALSE); +dane_data_len = store_get(i * sizeof(int), FALSE); i = 0; for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; @@ -2232,6 +3196,7 @@ for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr; ) if (rr->type == T_TLSA && rr->size > 3) { const uschar * p = rr->data; +/*XXX need somehow to mark rr and its data as tainted. Doues this mean copying it? */ uint8_t usage = p[0], sel = p[1], type = p[2]; DEBUG(D_tls) @@ -2270,6 +3235,142 @@ return TRUE; +#ifdef EXIM_HAVE_TLS_RESUME +/* On the client, get any stashed session for the given IP from hints db +and apply it to the ssl-connection for attempted resumption. Although +there is a gnutls_session_ticket_enable_client() interface it is +documented as unnecessary (as of 3.6.7) as "session tickets are emabled +by deafult". There seems to be no way to disable them, so even hosts not +enabled by the transport option will be sent a ticket request. We will +however avoid storing and retrieving session information. */ + +static void +tls_retrieve_session(tls_support * tlsp, gnutls_session_t session, + host_item * host, smtp_transport_options_block * ob) +{ +tlsp->resumption = RESUME_SUPPORTED; +if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK) + { + dbdata_tls_session * dt; + int len, rc; + open_db dbblock, * dbm_file; + + DEBUG(D_tls) + debug_printf("check for resumable session for %s\n", host->address); + tlsp->host_resumable = TRUE; + tlsp->resumption |= RESUME_CLIENT_REQUESTED; + if ((dbm_file = dbfn_open(US"tls", O_RDONLY, &dbblock, FALSE, FALSE))) + { + /* Key for the db is the IP. We'd like to filter the retrieved session + for ticket advisory expiry, but 3.6.1 seems to give no access to that */ + + if ((dt = dbfn_read_with_length(dbm_file, host->address, &len))) + if (!(rc = gnutls_session_set_data(session, + CUS dt->session, (size_t)len - sizeof(dbdata_tls_session)))) + { + DEBUG(D_tls) debug_printf("good session\n"); + tlsp->resumption |= RESUME_CLIENT_SUGGESTED; + } + else DEBUG(D_tls) debug_printf("setting session resumption data: %s\n", + US gnutls_strerror(rc)); + dbfn_close(dbm_file); + } + } +} + + +static void +tls_save_session(tls_support * tlsp, gnutls_session_t session, const host_item * host) +{ +/* TLS 1.2 - we get both the callback and the direct posthandshake call, +but this flag is not set until the second. TLS 1.3 it's the other way about. +Keep both calls as the session data cannot be extracted before handshake +completes. */ + +if (gnutls_session_get_flags(session) & GNUTLS_SFLAGS_SESSION_TICKET) + { + gnutls_datum_t tkt; + int rc; + + DEBUG(D_tls) debug_printf("server offered session ticket\n"); + tlsp->ticket_received = TRUE; + tlsp->resumption |= RESUME_SERVER_TICKET; + + if (tlsp->host_resumable) + if (!(rc = gnutls_session_get_data2(session, &tkt))) + { + open_db dbblock, * dbm_file; + int dlen = sizeof(dbdata_tls_session) + tkt.size; + dbdata_tls_session * dt = store_get(dlen, TRUE); + + DEBUG(D_tls) debug_printf("session data size %u\n", (unsigned)tkt.size); + memcpy(dt->session, tkt.data, tkt.size); + gnutls_free(tkt.data); + + if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE))) + { + /* key for the db is the IP */ + dbfn_delete(dbm_file, host->address); + dbfn_write(dbm_file, host->address, dt, dlen); + dbfn_close(dbm_file); + + DEBUG(D_tls) + debug_printf("wrote session db (len %u)\n", (unsigned)dlen); + } + } + else DEBUG(D_tls) + debug_printf("extract session data: %s\n", US gnutls_strerror(rc)); + } +} + + +/* With a TLS1.3 session, the ticket(s) are not seen until +the first data read is attempted. And there's often two of them. +Pick them up with this callback. We are also called for 1.2 +but we do nothing. +*/ +static int +tls_client_ticket_cb(gnutls_session_t sess, u_int htype, unsigned when, + unsigned incoming, const gnutls_datum_t * msg) +{ +exim_gnutls_state_st * state = gnutls_session_get_ptr(sess); +tls_support * tlsp = state->tlsp; + +DEBUG(D_tls) debug_printf("newticket cb\n"); + +if (!tlsp->ticket_received) + tls_save_session(tlsp, sess, state->host); +return 0; +} + + +static void +tls_client_resume_prehandshake(exim_gnutls_state_st * state, + tls_support * tlsp, host_item * host, + smtp_transport_options_block * ob) +{ +gnutls_session_set_ptr(state->session, state); +gnutls_handshake_set_hook_function(state->session, + GNUTLS_HANDSHAKE_NEW_SESSION_TICKET, GNUTLS_HOOK_POST, tls_client_ticket_cb); + +tls_retrieve_session(tlsp, state->session, host, ob); +} + +static void +tls_client_resume_posthandshake(exim_gnutls_state_st * state, + tls_support * tlsp, host_item * host) +{ +if (gnutls_session_is_resumed(state->session)) + { + DEBUG(D_tls) debug_printf("Session resumed\n"); + tlsp->resumption |= RESUME_USED; + } + +tls_save_session(tlsp, state->session, host); +} +#endif /* !DISABLE_TLS_RESUME */ + + /************************************************* * Start a TLS session in a client * *************************************************/ @@ -2277,36 +3378,29 @@ return TRUE; /* Called from the smtp transport after STARTTLS has been accepted. Arguments: - fd the fd of the connection - host connected host (for messages and option-tests) - addr the first address (not used) - tb transport (always smtp) - tlsa_dnsa non-NULL, either request or require dane for this host, and - a TLSA record found. Therefore, dane verify required. - Which implies cert must be requested and supplied, dane - verify must pass, and cert verify irrelevant (incl. - hostnames), and (caller handled) require_tls - tlsp record details of channel configuration - errstr error string pointer - -Returns: Pointer to TLS session context, or NULL on error + cctx connection context + conn_args connection details + cookie datum for randomness (not used) + tlsp record details of channel configuration here; must be non-NULL + errstr error string pointer + +Returns: TRUE for success with TLS session context set in smtp context, + FALSE on error */ -void * -tls_client_start(int fd, host_item *host, - address_item *addr ARG_UNUSED, - transport_instance * tb, -#ifdef SUPPORT_DANE - dns_answer * tlsa_dnsa, -#endif - tls_support * tlsp, uschar ** errstr) +BOOL +tls_client_start(client_conn_ctx * cctx, smtp_connect_args * conn_args, + void * cookie ARG_UNUSED, + tls_support * tlsp, uschar ** errstr) { -smtp_transport_options_block *ob = tb +host_item * host = conn_args->host; /* for msgs and option-tests */ +transport_instance * tb = conn_args->tblock; /* always smtp or NULL */ +smtp_transport_options_block * ob = tb ? (smtp_transport_options_block *)tb->options_block : &smtp_transport_option_defaults; int rc; exim_gnutls_state_st * state = NULL; -uschar *cipher_list = NULL; +uschar * cipher_list = NULL; #ifndef DISABLE_OCSP BOOL require_ocsp = @@ -2315,15 +3409,20 @@ BOOL request_ocsp = require_ocsp ? TRUE : verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK; #endif -DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", fd); +DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", cctx->sock); #ifdef SUPPORT_DANE -if (tlsa_dnsa && ob->dane_require_tls_ciphers) +/* If dane is flagged, have either request or require dane for this host, and +a TLSA record found. Therefore, dane verify required. Which implies cert must +be requested and supplied, dane verify must pass, and cert verify irrelevant +(incl. hostnames), and (caller handled) require_tls and sni=$domain */ + +if (conn_args->dane && ob->dane_require_tls_ciphers) { - /* not using expand_check_tlsvar because not yet in state */ + /* not using Expand_check_tlsvar because not yet in state */ if (!expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers", &cipher_list, errstr)) - return NULL; + return FALSE; cipher_list = cipher_list && *cipher_list ? ob->dane_require_tls_ciphers : ob->tls_require_ciphers; } @@ -2332,10 +3431,41 @@ if (tlsa_dnsa && ob->dane_require_tls_ciphers) if (!cipher_list) cipher_list = ob->tls_require_ciphers; -if (tls_init(host, ob->tls_certificate, ob->tls_privatekey, - ob->tls_sni, ob->tls_verify_certificates, ob->tls_crl, - cipher_list, &state, tlsp, errstr) != OK) - return NULL; + { +#ifdef MEASURE_TIMING + struct timeval t0; + gettimeofday(&t0, NULL); +#endif + + if (tls_init(host, ob, cipher_list, &state, tlsp, errstr) != OK) + return FALSE; + +#ifdef MEASURE_TIMING + report_time_since(&t0, US"client tls_init (delta)"); +#endif + } + +if (ob->tls_alpn) +#ifdef EXIM_HAVE_ALPN + { + const gnutls_datum_t * plist; + unsigned plen; + + if (!tls_alpn_plist(ob->tls_alpn, &plist, &plen, errstr)) + return FALSE; + if (plist) + if (gnutls_alpn_set_protocols(state->session, plist, plen, 0) != 0) + { + tls_error(US"alpn init", NULL, state->host, errstr); + return FALSE; + } + else + DEBUG(D_tls) debug_printf("Setting TLS ALPN '%s'\n", ob->tls_alpn); + } +#else + log_write(0, LOG_MAIN, "ALPN unusable with this GnuTLS library version; ignoring \"%s\"\n", + ob->tls_alpn); +#endif { int dh_min_bits = ob->tls_dh_min_bits; @@ -2359,10 +3489,10 @@ set but both tls_verify_hosts and tls_try_verify_hosts are unset. Check only the specified host patterns if one of them is defined */ #ifdef SUPPORT_DANE -if (tlsa_dnsa && dane_tlsa_load(state, tlsa_dnsa)) +if (conn_args->dane && dane_tlsa_load(state, &conn_args->tlsa_dnsa)) { DEBUG(D_tls) - debug_printf("TLS: server certificate DANE required.\n"); + debug_printf("TLS: server certificate DANE required\n"); state->verify_requirement = VERIFY_DANE; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); } @@ -2377,7 +3507,7 @@ else { tls_client_setup_hostname_checks(host, state, ob); DEBUG(D_tls) - debug_printf("TLS: server certificate verification required.\n"); + debug_printf("TLS: server certificate verification required\n"); state->verify_requirement = VERIFY_REQUIRED; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); } @@ -2385,14 +3515,14 @@ else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK) { tls_client_setup_hostname_checks(host, state, ob); DEBUG(D_tls) - debug_printf("TLS: server certificate verification optional.\n"); + debug_printf("TLS: server certificate verification optional\n"); state->verify_requirement = VERIFY_OPTIONAL; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUEST); } else { DEBUG(D_tls) - debug_printf("TLS: server certificate verification not required.\n"); + debug_printf("TLS: server certificate verification not required\n"); state->verify_requirement = VERIFY_NONE; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); } @@ -2405,25 +3535,29 @@ if (request_ocsp) if ((rc = gnutls_ocsp_status_request_enable_client(state->session, NULL, 0, NULL)) != OK) { - tls_error(US"cert-status-req", US gnutls_strerror(rc), state->host, errstr); - return NULL; + tls_error_gnu(state, US"cert-status-req", rc, errstr); + return FALSE; } tlsp->ocsp = OCSP_NOT_RESP; } #endif +#ifdef EXIM_HAVE_TLS_RESUME +tls_client_resume_prehandshake(state, tlsp, host, ob); +#endif + #ifndef DISABLE_EVENT if (tb && tb->event_action) { state->event_action = tb->event_action; gnutls_session_set_ptr(state->session, state); - gnutls_certificate_set_verify_function(state->x509_cred, verify_cb); + gnutls_certificate_set_verify_function(state->lib_state.x509_cred, verify_cb); } #endif -gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) fd); -state->fd_in = fd; -state->fd_out = fd; +gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) cctx->sock); +state->fd_in = cctx->sock; +state->fd_out = cctx->sock; DEBUG(D_tls) debug_printf("about to gnutls_handshake\n"); /* There doesn't seem to be a built-in timeout on connection. */ @@ -2443,67 +3577,123 @@ if (rc != GNUTLS_E_SUCCESS) tls_error(US"gnutls_handshake", US"timed out", state->host, errstr); } else - tls_error(US"gnutls_handshake", US gnutls_strerror(rc), state->host, errstr); - return NULL; + tls_error_gnu(state, US"gnutls_handshake", rc, errstr); + return FALSE; } -DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n"); +DEBUG(D_tls) post_handshake_debug(state); /* Verify late */ if (!verify_certificate(state, errstr)) { tls_error(US"certificate verification failed", *errstr, state->host, errstr); - return NULL; + return FALSE; } +#ifdef GNUTLS_SFLAGS_EXT_MASTER_SECRET +if (gnutls_session_get_flags(state->session) & GNUTLS_SFLAGS_EXT_MASTER_SECRET) + tlsp->ext_master_secret = TRUE; +#endif + #ifndef DISABLE_OCSP -if (require_ocsp) +if (request_ocsp) { DEBUG(D_tls) { gnutls_datum_t stapling; gnutls_ocsp_resp_t resp; gnutls_datum_t printed; - if ( (rc= gnutls_ocsp_status_request_get(state->session, &stapling)) == 0 - && (rc= gnutls_ocsp_resp_init(&resp)) == 0 - && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0 - && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_FULL, &printed)) == 0 - ) - { - debug_printf("%.4096s", printed.data); - gnutls_free(printed.data); - } - else - (void) tls_error(US"ocsp decode", US gnutls_strerror(rc), state->host, errstr); + unsigned idx = 0; + + for (; +# ifdef GNUTLS_OCSP_STATUS_REQUEST_GET2 + (rc = gnutls_ocsp_status_request_get2(state->session, idx, &stapling)) == 0; +#else + (rc = gnutls_ocsp_status_request_get(state->session, &stapling)) == 0; +#endif + idx++) + if ( (rc= gnutls_ocsp_resp_init(&resp)) == 0 + && (rc= gnutls_ocsp_resp_import(resp, &stapling)) == 0 + && (rc= gnutls_ocsp_resp_print(resp, GNUTLS_OCSP_PRINT_COMPACT, &printed)) == 0 + ) + { + debug_printf("%.4096s", printed.data); + gnutls_free(printed.data); + } + else + (void) tls_error_gnu(state, US"ocsp decode", rc, errstr); + if (idx == 0 && rc) + (void) tls_error_gnu(state, US"ocsp decode", rc, errstr); } if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0) { tlsp->ocsp = OCSP_FAILED; tls_error(US"certificate status check failed", NULL, state->host, errstr); - return NULL; + if (require_ocsp) + return FALSE; + } + else + { + DEBUG(D_tls) debug_printf("Passed OCSP checking\n"); + tlsp->ocsp = OCSP_VFIED; } - DEBUG(D_tls) debug_printf("Passed OCSP checking\n"); - tlsp->ocsp = OCSP_VFIED; } #endif -/* Figure out peer DN, and if authenticated, etc. */ +#ifdef EXIM_HAVE_TLS_RESUME +tls_client_resume_posthandshake(state, tlsp, host); +#endif + +#ifdef EXIM_HAVE_ALPN +if (ob->tls_alpn) /* We requested. See what was negotiated. */ + { + gnutls_datum_t p = {.size = 0}; -if (peer_status(state, errstr) != OK) - return NULL; + if (gnutls_alpn_get_selected_protocol(state->session, &p) == 0) + { DEBUG(D_tls) debug_printf("ALPN negotiated: '%.*s'\n", (int)p.size, p.data); } + else if (verify_check_given_host(CUSS &ob->hosts_require_alpn, host) == OK) + { + gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_NO_APPLICATION_PROTOCOL); + tls_error(US"handshake", US"ALPN required but not negotiated", state->host, errstr); + return FALSE; + } + else + DEBUG(D_tls) debug_printf("No ALPN negotiated"); + } +#endif /* Sets various Exim expansion variables; may need to adjust for ACL callouts */ extract_exim_vars_from_tls_state(state); -return state; +cctx->tls_ctx = state; +return TRUE; } +/* +Arguments: + ct_ctx client TLS context pointer, or NULL for the one global server context +*/ + +void +tls_shutdown_wr(void * ct_ctx) +{ +exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; +tls_support * tlsp = state->tlsp; + +if (!tlsp || tlsp->active.sock < 0) return; /* TLS was not active */ + +tls_write(ct_ctx, NULL, 0, FALSE); /* flush write buffer */ + +HDEBUG(D_transport|D_tls|D_acl|D_v) debug_printf_indent(" SMTP(TLS shutdown)>>\n"); +gnutls_bye(state->session, GNUTLS_SHUT_WR); +} + /************************************************* * Close down a TLS session * *************************************************/ @@ -2514,37 +3704,55 @@ would tamper with the TLS session in the parent process). Arguments: ct_ctx client context pointer, or NULL for the one global server context - shutdown 1 if TLS close-alert is to be sent, - 2 if also response to be waited for + do_shutdown 0 no data-flush or TLS close-alert + 1 if TLS close-alert is to be sent, + 2 if also response to be waited for (2s timeout) Returns: nothing */ void -tls_close(void * ct_ctx, int shutdown) +tls_close(void * ct_ctx, int do_shutdown) { exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; +tls_support * tlsp = state->tlsp; -if (!state->tlsp || state->tlsp->active.sock < 0) return; /* TLS was not active */ +if (!tlsp || tlsp->active.sock < 0) return; /* TLS was not active */ -if (shutdown) +if (do_shutdown) { DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n", - shutdown > 1 ? " (with response-wait)" : ""); + do_shutdown > 1 ? " (with response-wait)" : ""); + + tls_write(ct_ctx, NULL, 0, FALSE); /* flush write buffer */ ALARM(2); - gnutls_bye(state->session, shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR); + gnutls_bye(state->session, do_shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR); ALARM_CLR(0); } +if (!ct_ctx) /* server */ + { + receive_getc = smtp_getc; + receive_getbuf = smtp_getbuf; + receive_get_cache = smtp_get_cache; + receive_hasc = smtp_hasc; + receive_ungetc = smtp_ungetc; + receive_feof = smtp_feof; + receive_ferror = smtp_ferror; + } + gnutls_deinit(state->session); -gnutls_certificate_free_credentials(state->x509_cred); +gnutls_certificate_free_credentials(state->lib_state.x509_cred); +state->lib_state = null_tls_preload; + +tlsp->active.sock = -1; +tlsp->active.tls_ctx = NULL; +/* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */ +tlsp->channelbinding = NULL; -state->tlsp->active.sock = -1; -state->tlsp->active.tls_ctx = NULL; if (state->xfer_buffer) store_free(state->xfer_buffer); -memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); } @@ -2556,12 +3764,13 @@ tls_refill(unsigned lim) exim_gnutls_state_st * state = &state_server; ssize_t inbytes; -DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, %u)\n", +DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(session=%p, buffer=%p, buffersize=%u)\n", state->session, state->xfer_buffer, ssl_xfer_buffer_size); sigalrm_seen = FALSE; if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); +errno = 0; do inbytes = gnutls_record_recv(state->session, state->xfer_buffer, MIN(ssl_xfer_buffer_size, lim)); @@ -2592,28 +3801,7 @@ if (sigalrm_seen) else if (inbytes == 0) { DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); - - receive_getc = smtp_getc; - receive_getbuf = smtp_getbuf; - receive_get_cache = smtp_get_cache; - receive_ungetc = smtp_ungetc; - receive_feof = smtp_feof; - receive_ferror = smtp_ferror; - receive_smtp_buffered = smtp_buffered; - - gnutls_deinit(state->session); - gnutls_certificate_free_credentials(state->x509_cred); - - state->session = NULL; - state->tlsp->active.sock = -1; - state->tlsp->active.tls_ctx = NULL; - state->tlsp->bits = 0; - state->tlsp->certificate_verified = FALSE; - tls_channelbinding_b64 = NULL; - state->tlsp->cipher = NULL; - state->tlsp->peercert = NULL; - state->tlsp->peerdn = NULL; - + tls_close(NULL, TLS_NO_SHUTDOWN); return FALSE; } @@ -2621,7 +3809,7 @@ else if (inbytes == 0) else if (inbytes < 0) { - DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv(\n", __FUNCTION__); + DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv\n", __FUNCTION__); record_io_error(state, (int) inbytes, US"recv", NULL); state->xfer_error = TRUE; return FALSE; @@ -2644,7 +3832,7 @@ Only used by the server-side TLS. This feeds DKIM and should be used for all message-body reads. -Arguments: lim Maximum amount to read/bufffer +Arguments: lim Maximum amount to read/buffer Returns: the next character or EOF */ @@ -2662,6 +3850,13 @@ if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) return state->xfer_buffer[state->xfer_buffer_lwm++]; } +BOOL +tls_hasc(void) +{ +exim_gnutls_state_st * state = &state_server; +return state->xfer_buffer_lwm < state->xfer_buffer_hwm; +} + uschar * tls_getbuf(unsigned * len) { @@ -2686,12 +3881,15 @@ return buf; } +/* Get up to the given number of bytes from any cached data, and feed to dkim. */ void -tls_get_cache() +tls_get_cache(unsigned lim) { #ifndef DISABLE_DKIM exim_gnutls_state_st * state = &state_server; int n = state->xfer_buffer_hwm - state->xfer_buffer_lwm; +if (n > lim) + n = lim; if (n > 0) dkim_exim_verify_feed(state->xfer_buffer+state->xfer_buffer_lwm, n); #endif @@ -2699,15 +3897,13 @@ if (n > 0) BOOL -tls_could_read(void) +tls_could_getc(void) { return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm || gnutls_record_check_pending(state_server.session) > 0; } - - /************************************************* * Read bytes from TLS channel * *************************************************/ @@ -2740,9 +3936,10 @@ if (state->xfer_buffer_lwm < state->xfer_buffer_hwm) state->xfer_buffer_hwm - state->xfer_buffer_lwm); DEBUG(D_tls) - debug_printf("Calling gnutls_record_recv(%p, %p, " SIZE_T_FMT ")\n", + debug_printf("Calling gnutls_record_recv(session=%p, buffer=%p, len=" SIZE_T_FMT ")\n", state->session, buff, len); +errno = 0; do inbytes = gnutls_record_recv(state->session, buff, len); while (inbytes == GNUTLS_E_AGAIN); @@ -2754,7 +3951,7 @@ if (inbytes == 0) } else { - DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv(\n", __FUNCTION__); + DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv\n", __FUNCTION__); record_io_error(state, (int)inbytes, US"recv", NULL); } @@ -2775,6 +3972,9 @@ Arguments: len number of bytes more more data expected soon +Calling with len zero and more unset will flush buffered writes. The buff +argument can be null for that case. + Returns: the number of bytes after a successful write, -1 after a failed write */ @@ -2785,10 +3985,14 @@ tls_write(void * ct_ctx, const uschar * buff, size_t len, BOOL more) ssize_t outbytes; size_t left = len; exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; -#ifdef SUPPORT_CORK -static BOOL corked = FALSE; -if (more && !corked) gnutls_record_cork(state->session); +#ifdef SUPPORT_CORK +if (more && !state->corked) + { + DEBUG(D_tls) debug_printf("gnutls_record_cork(session=%p)\n", state->session); + gnutls_record_cork(state->session); + state->corked = TRUE; + } #endif DEBUG(D_tls) debug_printf("%s(%p, " SIZE_T_FMT "%s)\n", __FUNCTION__, @@ -2796,18 +4000,36 @@ DEBUG(D_tls) debug_printf("%s(%p, " SIZE_T_FMT "%s)\n", __FUNCTION__, while (left > 0) { - DEBUG(D_tls) debug_printf("gnutls_record_send(SSL, %p, " SIZE_T_FMT ")\n", - buff, left); + DEBUG(D_tls) debug_printf("gnutls_record_send(session=%p, buffer=%p, left=" SIZE_T_FMT ")\n", + state->session, buff, left); + errno = 0; do outbytes = gnutls_record_send(state->session, buff, left); while (outbytes == GNUTLS_E_AGAIN); DEBUG(D_tls) debug_printf("outbytes=" SSIZE_T_FMT "\n", outbytes); + if (outbytes < 0) { - DEBUG(D_tls) debug_printf("%s: gnutls_record_send err\n", __FUNCTION__); - record_io_error(state, outbytes, US"send", NULL); +#ifdef GNUTLS_E_PREMATURE_TERMINATION + if ( outbytes == GNUTLS_E_PREMATURE_TERMINATION && errno == ECONNRESET + && !ct_ctx && f.smtp_in_quit + ) + { /* Outlook, dammit */ + if (LOGGING(protocol_detail)) + log_write(0, LOG_MAIN, "[%s] after QUIT, client reset TCP before" + " SMTP response and TLS close\n", sender_host_address); + else + DEBUG(D_tls) debug_printf("[%s] SSL_write: after QUIT," + " client reset TCP before TLS close\n", sender_host_address); + } + else +#endif + { + DEBUG(D_tls) debug_printf("%s: gnutls_record_send err\n", __FUNCTION__); + record_io_error(state, outbytes, US"send", NULL); + } return -1; } if (outbytes == 0) @@ -2829,10 +4051,25 @@ if (len > INT_MAX) } #ifdef SUPPORT_CORK -if (more != corked) +if (!more && state->corked) { - if (!more) (void) gnutls_record_uncork(state->session, 0); - corked = more; + DEBUG(D_tls) debug_printf("gnutls_record_uncork(session=%p)\n", state->session); + do + /* We can't use GNUTLS_RECORD_WAIT here, as it retries on + GNUTLS_E_AGAIN || GNUTLS_E_INTR, which would break our timeout set by alarm(). + The GNUTLS_E_AGAIN should not happen ever, as our sockets are blocking anyway. + But who knows. (That all relies on the fact that GNUTLS_E_INTR and GNUTLS_E_AGAIN + match the EINTR and EAGAIN errno values.) */ + outbytes = gnutls_record_uncork(state->session, 0); + while (outbytes == GNUTLS_E_AGAIN); + + if (outbytes < 0) + { + record_io_error(state, len, US"uncork", NULL); + return -1; + } + + state->corked = FALSE; } #endif @@ -2881,7 +4118,7 @@ if (i < needed_len) i = gnutls_rnd(GNUTLS_RND_NONCE, smallbuf, needed_len); if (i < 0) { - DEBUG(D_all) debug_printf("gnutls_rnd() failed, using fallback.\n"); + DEBUG(D_all) debug_printf("gnutls_rnd() failed, using fallback\n"); return vaguely_random_number_fallback(max); } r = 0; @@ -2922,24 +4159,33 @@ gnutls_priority_t priority_cache; const char *errpos; uschar * dummy_errstr; -#define validate_check_rc(Label) do { \ +#ifdef GNUTLS_AUTO_GLOBAL_INIT +# define validate_check_rc(Label) do { \ + if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) \ + return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0) +# define return_deinit(Label) do { return (Label); } while (0) +#else +# define validate_check_rc(Label) do { \ if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) gnutls_global_deinit(); \ - return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0) -#define return_deinit(Label) do { gnutls_global_deinit(); return (Label); } while (0) + return string_sprintf("%s failed: %s", (Label), gnutls_strerror(rc)); } } while (0) +# define return_deinit(Label) do { gnutls_global_deinit(); return (Label); } while (0) +#endif if (exim_gnutls_base_init_done) log_write(0, LOG_MAIN|LOG_PANIC, "already initialised GnuTLS, Exim developer bug"); -#ifdef HAVE_GNUTLS_PKCS11 +#if defined(HAVE_GNUTLS_PKCS11) && !defined(GNUTLS_AUTO_PKCS11_MANUAL) if (!gnutls_allow_auto_pkcs11) { rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL); validate_check_rc(US"gnutls_pkcs11_init"); } #endif +#ifndef GNUTLS_AUTO_GLOBAL_INIT rc = gnutls_global_init(); validate_check_rc(US"gnutls_global_init()"); +#endif exim_gnutls_base_init_done = TRUE; if (!(tls_require_ciphers && *tls_require_ciphers)) @@ -2958,11 +4204,13 @@ DEBUG(D_tls) rc = gnutls_priority_init(&priority_cache, CS expciphers, &errpos); validate_check_rc(string_sprintf( "gnutls_priority_init(%s) failed at offset %ld, \"%.8s..\"", - expciphers, errpos - CS expciphers, errpos)); + expciphers, (long)(errpos - CS expciphers), errpos)); #undef return_deinit #undef validate_check_rc +#ifndef GNUTLS_AUTO_GLOBAL_INIT gnutls_global_deinit(); +#endif return NULL; } @@ -2989,6 +4237,7 @@ fprintf(f, "Library version: GnuTLS: Compile: %s\n" gnutls_check_version(NULL)); } +#endif /*!MACRO_PREDEF*/ /* vi: aw ai sw=2 */ /* End of tls-gnu.c */