X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/a8af957d93348cd8c74b852431fae7e65bc8297f..7044dd8fd62e215572ecf5a2c7f1bb9581cf6628:/src/src/tls-gnu.c diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index 91ddc579b..cf3804982 100644 --- a/src/src/tls-gnu.c +++ b/src/src/tls-gnu.c @@ -3,6 +3,7 @@ *************************************************/ /* Copyright (c) University of Cambridge 1995 - 2018 */ +/* Copyright (c) The Exim Maintainers 2020 */ /* See the file NOTICE for conditions of use and distribution. */ /* Copyright (c) Phil Pennock 2012 */ @@ -53,6 +54,9 @@ 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 @@ -70,12 +74,30 @@ require current GnuTLS, then we'll drop support for the ancient libraries). #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 >= 0x030600 +# define GNUTLS_AUTO_DHPARAMS +#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 @@ -89,6 +111,14 @@ 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 + #ifndef DISABLE_OCSP # include #endif @@ -99,6 +129,26 @@ require current GnuTLS, then we'll drop support for the ancient libraries). #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 +} +#else + + /* GnuTLS 2 vs 3 GnuTLS 3 only: @@ -123,7 +173,7 @@ 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 { @@ -133,10 +183,17 @@ typedef struct exim_gnutls_state { 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; @@ -169,50 +226,12 @@ 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 @@ -228,15 +247,15 @@ XXX But see gnutls_session_get_ptr() static exim_gnutls_state_st state_server; +#ifndef GNUTLS_AUTO_DHPARAMS /* 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 don't want to repeat this. */ static gnutls_dh_params_t dh_server_params = NULL; +#endif -/* No idea how this value was chosen; preserving it. Default is 3600. */ - -static const int ssl_session_timeout = 200; +static int ssl_session_timeout = 7200; /* Two hours */ static const uschar * const exim_default_gnutls_priority = US"NORMAL"; @@ -246,8 +265,12 @@ 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_TLS_RESUME +static gnutls_datum_t server_sessticket_key; +#endif /* ------------------------------------------------------------------------ */ /* macros */ @@ -305,12 +328,30 @@ 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 +/* Daemon one-time initialisation */ +void +tls_daemon_init(void) +{ +#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). */ + +static BOOL once = FALSE; +if (once) return; +once = TRUE; +gnutls_session_ticket_key_generate(&server_sessticket_key); /* >= 2.10.0 */ +if (f.running_in_test_harness) ssl_session_timeout = 6; +#endif +} /* ------------------------------------------------------------------------ */ /* Static functions */ @@ -383,11 +424,14 @@ 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("A TLS fatal alert has been received: %s", - 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); @@ -449,7 +493,8 @@ 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 @@ -463,7 +508,6 @@ 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; @@ -474,12 +518,6 @@ 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; @@ -487,10 +525,10 @@ 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; @@ -498,11 +536,15 @@ 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 @@ -522,6 +564,7 @@ tlsp->sni = state->received_sni; +#ifndef GNUTLS_AUTO_DHPARAMS /************************************************* * Setup up DH parameters * *************************************************/ @@ -544,7 +587,7 @@ init_server_dh(uschar ** errstr) { int fd, rc; unsigned int dh_bits; -gnutls_datum_t m; +gnutls_datum_t m = {.data = NULL, .size = 0}; uschar filename_buf[PATH_MAX]; uschar *filename = NULL; size_t sz; @@ -557,9 +600,6 @@ DEBUG(D_tls) debug_printf("Initialising GnuTLS server params.\n"); if ((rc = gnutls_dh_params_init(&dh_server_params))) return tls_error_gnu(US"gnutls_dh_params_init", rc, host, errstr); -m.data = NULL; -m.size = 0; - if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam, errstr)) return DEFER; @@ -655,7 +695,7 @@ if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) } m.size = statbuf.st_size; - if (!(m.data = malloc(m.size))) + if (!(m.data = store_malloc(m.size))) { fclose(fp); return tls_error_sys(US"malloc failed", errno, NULL, errstr); @@ -664,13 +704,13 @@ if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) { saved_errno = errno; fclose(fp); - free(m.data); + 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); + store_free(m.data); if (rc) return tls_error_gnu(US"gnutls_dh_params_import_pkcs3", rc, host, errstr); DEBUG(D_tls) debug_printf("read D-H parameters from file \"%s\"\n", filename); @@ -686,7 +726,7 @@ 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 @@ -709,14 +749,12 @@ if (rc < 0) 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. - * But there's no way to ask GnuTLS how many bits there really are. - * We can ask how many bits were used in a TLS session, but that's it! - * The prime itself is hidden behind too much abstraction. - * So we ask for less, and proceed on a wing and a prayer. - * First attempt, subtracted 3 for 2233 and got 2240. - */ + /* GnuTLS overshoots! If we ask for 2236, we might get 2237 or more. But + there's no way to ask GnuTLS how many bits there really are. We can ask + how many bits were used in a TLS session, but that's it! The prime itself + is hidden behind too much abstraction. So we ask for less, and proceed on + a wing and a prayer. First attempt, subtracted 3 for 2233 and got 2240. */ + if (dh_bits >= EXIM_CLIENT_DH_MIN_BITS + 10) { dh_bits_gen = dh_bits - 10; @@ -743,25 +781,25 @@ if (rc < 0) return tls_error_gnu(US"gnutls_dh_params_export_pkcs3(NULL) sizing", rc, host, errstr); m.size = sz; - if (!(m.data = malloc(m.size))) + 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 */ if ((rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, m.data, &sz))) { - free(m.data); + store_free(m.data); return tls_error_gnu(US"gnutls_dh_params_export_pkcs3() real", rc, host, 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); + 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_sys(US"TLS cache write D-H params final newline failed", errno, NULL, errstr); @@ -779,6 +817,7 @@ if (rc < 0) DEBUG(D_tls) debug_printf("initialized server D-H parameters\n"); return OK; } +#endif @@ -794,13 +833,19 @@ 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 + 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 @@ -875,6 +920,151 @@ return -rc; } +#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. */ + +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); + +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; + } + +tls_in.ocsp = OCSP_VFY_NOT_TRIED; +return 0; +} +#endif + + +#ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE +/* Make a note that we saw a status-request */ +static int +tls_server_clienthello_ext(void * ctx, unsigned tls_id, + const unsigned char *data, unsigned size) +{ +/* https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml */ +if (tls_id == 5) /* status_request */ + { + DEBUG(D_tls) debug_printf("Seen status_request extension from client\n"); + tls_in.ocsp = OCSP_NOT_RESP; + } +return 0; +} + +/* 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); +} + + +/* 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 */ + { + 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; +} + +/* 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 +/*XXX crashes */ +return gnutls_ext_raw_parse(NULL, tls_server_servercerts_ext, msg, 0); +#endif +} +#endif + +/*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) + +This is different to tls1.2 - where it is a separate record (wireshark term) / handshake message (gnutls term). +*/ + +#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) + { + DEBUG(D_tls) debug_printf("Permitting known bad OCSP response\n"); + exim_testharness_disable_ocsp_validity_check = TRUE; + } +} +#endif + /************************************************* * Variables re-expanded post-SNI * *************************************************/ @@ -935,6 +1125,18 @@ if ((rc = gnutls_certificate_allocate_credentials(&state->x509_cred))) #ifdef SUPPORT_SRV_OCSP_STACK gnutls_certificate_set_flags(state->x509_cred, GNUTLS_CERTIFICATE_API_V2); + +# if !defined(DISABLE_OCSP) && defined(SUPPORT_GNUTLS_EXT_RAW_PARSE) +if (!host && 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(state->x509_cred, + GNUTLS_CERTIFICATE_API_V2 | GNUTLS_CERTIFICATE_SKIP_OCSP_RESPONSE_CHECK); + } +# endif #endif /* remember: expand_check_tlsvar() is expand_check() but fiddling with @@ -962,7 +1164,7 @@ if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr)) /* tls_privatekey is optional, defaulting to same file as certificate */ -if (state->tls_privatekey == NULL || *state->tls_privatekey == '\0') +if (!state->tls_privatekey || !*state->tls_privatekey) { state->tls_privatekey = state->tls_certificate; state->exp_tls_privatekey = state->exp_tls_certificate; @@ -993,8 +1195,11 @@ if (state->exp_tls_certificate && *state->exp_tls_certificate) const uschar * olist; int csep = 0, ksep = 0, osep = 0, cnt = 0; uschar * cfile, * kfile, * ofile; - #ifndef DISABLE_OCSP +# ifdef SUPPORT_GNUTLS_EXT_RAW_PARSE + gnutls_x509_crt_fmt_t ocsp_fmt = GNUTLS_X509_FMT_DER; +# endif + if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", &ofile, errstr)) return DEFER; olist = ofile; @@ -1009,12 +1214,13 @@ if (state->exp_tls_certificate && *state->exp_tls_certificate) else { int gnutls_cert_index = -rc; - DEBUG(D_tls) debug_printf("TLS: cert/key %s registered\n", cfile); - - /* Set the OCSP stapling server info */ + DEBUG(D_tls) debug_printf("TLS: cert/key %d %s registered\n", + gnutls_cert_index, cfile); #ifndef DISABLE_OCSP if (tls_ocsp_file) + { + /* Set the OCSP stapling server info */ if (gnutls_buggy_ocsp) { DEBUG(D_tls) @@ -1022,37 +1228,63 @@ if (state->exp_tls_certificate && *state->exp_tls_certificate) } 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. */ + 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; + } -# ifdef SUPPORT_SRV_OCSP_STACK - if ((rc = gnutls_certificate_set_ocsp_status_request_function2( - state->x509_cred, gnutls_cert_index, - server_ocsp_stapling_cb, ofile))) + if ((rc = gnutls_certificate_set_ocsp_status_request_file2( + state->x509_cred, CCS ofile, gnutls_cert_index, + ocsp_fmt)) < 0) return tls_error_gnu( - US"gnutls_certificate_set_ocsp_status_request_function2", + US"gnutls_certificate_set_ocsp_status_request_file2", rc, host, errstr); + DEBUG(D_tls) + debug_printf(" %d response%s loaded\n", rc, rc>1 ? "s":""); + + /* Arrange callbacks for OCSP request observability */ + + gnutls_handshake_set_hook_function(state->session, + GNUTLS_HANDSHAKE_ANY, GNUTLS_HOOK_POST, tls_server_hook_cb); + # else - if (cnt++ > 0) +# if defined(SUPPORT_SRV_OCSP_STACK) + if ((rc = gnutls_certificate_set_ocsp_status_request_function2( + state->x509_cred, gnutls_cert_index, + server_ocsp_stapling_cb, ofile))) + return tls_error_gnu( + US"gnutls_certificate_set_ocsp_status_request_function2", + rc, host, errstr); + else +# endif { - DEBUG(D_tls) - debug_printf("oops; multiple OCSP files not supported\n"); - break; - } + 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); -# endif - - DEBUG(D_tls) debug_printf("OCSP response file = %s\n", ofile); + } +# endif /* SUPPORT_GNUTLS_EXT_RAW_PARSE */ } else DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n"); -#endif + } +#endif /* DISABLE_OCSP */ } } - else + else /* client */ { if (0 < (rc = tls_add_certfile(state, host, state->exp_tls_certificate, state->exp_tls_privatekey, errstr))) @@ -1105,7 +1337,7 @@ else { if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0) { - log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s " + log_write(0, LOG_MAIN|LOG_PANIC, "could not stat '%s' " "(tls_verify_certificates): %s", state->exp_tls_verify_certificates, strerror(errno)); return DEFER; @@ -1150,6 +1382,14 @@ else #endif gnutls_certificate_set_x509_trust_file(state->x509_cred, CS state->exp_tls_verify_certificates, 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) + gnutls_certificate_send_x509_rdn_sequence(state->session, 1); +#endif } if (cert_count < 0) @@ -1198,6 +1438,7 @@ tls_set_remaining_x509(exim_gnutls_state_st *state, uschar ** errstr) int rc; const host_item *host = state->host; /* macro should be reconsidered? */ +#ifndef GNUTLS_AUTO_DHPARAMS /* Create D-H parameters, or read them from the cache file. This function does its own SMTP error messaging. This only happens for the server, TLS D-H ignores client-side params. */ @@ -1206,8 +1447,11 @@ if (!state->host) { if (!dh_server_params) if ((rc = init_server_dh(errstr)) != OK) return rc; + + /* Unnecessary & discouraged with 3.6.0 or later */ gnutls_certificate_set_dh_params(state->x509_cred, dh_server_params); } +#endif /* Link the credentials to the session. */ @@ -1294,7 +1538,7 @@ if (!exim_gnutls_base_init_done) { DEBUG(D_tls) debug_printf("GnuTLS global init required.\n"); -#ifdef HAVE_GNUTLS_PKCS11 +#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 @@ -1305,8 +1549,10 @@ if (!exim_gnutls_base_init_done) return tls_error_gnu(US"gnutls_pkcs11_init", rc, host, errstr); #endif +#ifndef GNUTLS_AUTO_GLOBAL_INIT if ((rc = gnutls_global_init())) return tls_error_gnu(US"gnutls_global_init", rc, host, errstr); +#endif #if EXIM_GNUTLS_LIBRARY_LOG_LEVEL >= 0 DEBUG(D_tls) @@ -1331,7 +1577,7 @@ if (host) 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)); @@ -1423,6 +1669,9 @@ if ((rc = gnutls_priority_init(&state->priority_cache, CCS p, &errpos))) if ((rc = gnutls_priority_set(state->session, state->priority_cache))) return tls_error_gnu(US"gnutls_priority_set", rc, host, 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); /* Reduce security in favour of increased compatibility, if the admin @@ -1492,9 +1741,10 @@ Returns: OK/DEFER/FAIL */ static int -peer_status(exim_gnutls_state_st *state, uschar ** errstr) +peer_status(exim_gnutls_state_st * state, uschar ** errstr) { -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; @@ -1503,7 +1753,7 @@ 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) @@ -1513,23 +1763,24 @@ 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); +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(state->session); + gnutls_kx_get(session); old_pool = store_pool; { + tls_support * tlsp = state->tlsp; store_pool = POOL_PERM; #ifdef SUPPORT_GNUTLS_SESS_DESC { gstring * g = NULL; - uschar * s = US gnutls_session_get_desc(state->session), c; + 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) @@ -1540,11 +1791,17 @@ old_pool = store_pool; /* 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); + 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 */ @@ -1564,19 +1821,21 @@ old_pool = store_pool; 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); */ - state->tlsp->cipher = state->ciphersuite; - state->tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; + tlsp->cipher = state->ciphersuite; + tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; - state->tlsp->cipher_stdname = cipher_stdname_kcm(kx, cipher, mac); + tlsp->cipher_stdname = cipher_stdname_kcm(kx, cipher, mac); } store_pool = old_pool; /* 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 || cert_list_size == 0) { @@ -1588,7 +1847,7 @@ if (!cert_list || cert_list_size == 0) return OK; } -if ((ct = gnutls_certificate_type_get(state->session)) != GNUTLS_CRT_X509) +if ((ct = gnutls_certificate_type_get(session)) != GNUTLS_CRT_X509) { const uschar * ctn = US gnutls_certificate_type_get_name(ct); DEBUG(D_tls) @@ -1623,7 +1882,7 @@ 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)]"); @@ -1660,13 +1919,14 @@ 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 (state->verify_requirement == VERIFY_NONE) + return TRUE; -if ((rc = peer_status(state, errstr)) != OK || !state->peerdn) +if (rc != OK || !state->peerdn) { verify = GNUTLS_CERT_INVALID; *errstr = US"certificate not supplied"; @@ -1699,11 +1959,11 @@ 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))) @@ -1931,13 +2191,12 @@ 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"); else debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n", gnutls_strerror(rc), rc); - } return 0; } @@ -1950,7 +2209,7 @@ 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 */ @@ -1977,30 +2236,6 @@ return 0; -#ifndef DISABLE_OCSP - -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); - -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; - } - -tls_in.ocsp = OCSP_VFY_NOT_TRIED; -return 0; -} - -#endif - - #ifndef DISABLE_EVENT /* We use this callback to get observability and detail-level control @@ -2065,20 +2300,20 @@ return g; static void post_handshake_debug(exim_gnutls_state_st * state) { -debug_printf("gnutls_handshake was successful\n"); #ifdef SUPPORT_GNUTLS_SESS_DESC debug_printf("%s\n", gnutls_session_get_desc(state->session)); #endif + #ifdef SUPPORT_GNUTLS_KEYLOG -# ifdef GNUTLS_TLS1_3 +# ifdef EXIM_HAVE_TLS1_3 if (gnutls_protocol_get_version(state->session) < GNUTLS_TLS1_3) -#else +# else if (TRUE) -#endif +# endif { gnutls_datum_t c, s; gstring * gc, * gs; - /* we only want the client random and the master secret */ + /* 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); @@ -2087,13 +2322,73 @@ if (TRUE) } else debug_printf("To get keying info for TLS1.3 is hard:\n" - " set environment variable SSLKEYLOGFILE to a filename writable by uid exim\n" - " add SSLKEYLOGFILE to keep_environment in the exim config\n" - " run exim as root\n" - " if using sudo, add SSLKEYLOGFILE to env_keep in /etc/sudoers\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"); + } +} +#endif /* ------------------------------------------------------------------------ */ /* Exported functions */ @@ -2137,9 +2432,24 @@ 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, tls_certificate, tls_privatekey, + NULL, tls_verify_certificates, tls_crl, + 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_TLS_RESUME +tls_server_resume_prehandshake(state); +#endif /* If this is a host for which certificate verification is mandatory or optional, set up appropriately. */ @@ -2240,6 +2550,15 @@ if (rc != GNUTLS_E_SUCCESS) return FAIL; } +#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); /* Verify after the fact */ @@ -2256,10 +2575,6 @@ 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); @@ -2291,9 +2606,9 @@ 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", @@ -2325,8 +2640,8 @@ 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; @@ -2334,6 +2649,7 @@ 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) @@ -2372,6 +2688,142 @@ 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 * *************************************************/ @@ -2416,7 +2868,7 @@ DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", cctx->so /* 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 */ +(incl. hostnames), and (caller handled) require_tls and sni=$domain */ if (conn_args->dane && ob->dane_require_tls_ciphers) { @@ -2432,10 +2884,21 @@ if (conn_args->dane && 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 FALSE; + { +#ifdef MEASURE_TIMING + struct timeval t0; + gettimeofday(&t0, NULL); +#endif + + 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 FALSE; + +#ifdef MEASURE_TIMING + report_time_since(&t0, US"client tls_init (delta)"); +#endif + } { int dh_min_bits = ob->tls_dh_min_bits; @@ -2512,6 +2975,10 @@ if (request_ocsp) } #endif +#ifdef EXIM_HAVE_TLS_RESUME +tls_client_resume_prehandshake(state, tlsp, host, ob); +#endif + #ifndef DISABLE_EVENT if (tb && tb->event_action) { @@ -2557,24 +3024,39 @@ if (!verify_certificate(state, errstr)) 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 + 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(US"ocsp decode", rc, state->host, errstr); + if (idx == 0 && rc) (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr); } @@ -2582,17 +3064,20 @@ if (require_ocsp) { tlsp->ocsp = OCSP_FAILED; tls_error(US"certificate status check failed", NULL, state->host, errstr); - return FALSE; + 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. */ - -if (peer_status(state, errstr) != OK) - return FALSE; +#ifdef EXIM_HAVE_TLS_RESUME +tls_client_resume_posthandshake(state, tlsp, host); +#endif /* Sets various Exim expansion variables; may need to adjust for ACL callouts */ @@ -2625,8 +3110,9 @@ void tls_close(void * ct_ctx, int 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) { @@ -2638,12 +3124,26 @@ if (shutdown) ALARM_CLR(0); } +if (!ct_ctx) /* server */ + { + 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); +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)); } @@ -2657,7 +3157,7 @@ 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; @@ -2693,28 +3193,7 @@ 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; } @@ -2841,7 +3320,7 @@ 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); do @@ -2876,6 +3355,9 @@ 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 */ @@ -2886,10 +3368,14 @@ 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__, @@ -2897,18 +3383,35 @@ 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); 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) @@ -2930,10 +3433,25 @@ 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 @@ -3023,24 +3541,33 @@ 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)) @@ -3063,7 +3590,9 @@ validate_check_rc(string_sprintf( #undef return_deinit #undef validate_check_rc +#ifndef GNUTLS_AUTO_GLOBAL_INIT gnutls_global_deinit(); +#endif return NULL; } @@ -3090,6 +3619,7 @@ 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 */