X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=src%2Fsrc%2Ftls-gnu.c;h=383a00f4ededfc6b0aee181d9815f15f76259099;hp=5bdb21e6ee3447d6b9dc8198aa688bc1acbd3b12;hb=60d10ce7e68a5f2cf771a5c079521c8e4f18d157;hpb=d502442ac32f8964f6cf86469869cecb035d12c0 diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index 5bdb21e6e..383a00f4e 100644 --- a/src/src/tls-gnu.c +++ b/src/src/tls-gnu.c @@ -2,7 +2,7 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2014 */ +/* Copyright (c) University of Cambridge 1995 - 2015 */ /* See the file NOTICE for conditions of use and distribution. */ /* Copyright (c) Phil Pennock 2012 */ @@ -42,11 +42,24 @@ require current GnuTLS, then we'll drop support for the ancient libraries). /* needed to disable PKCS11 autoload unless requested */ #if GNUTLS_VERSION_NUMBER >= 0x020c00 # include +# define SUPPORT_PARAM_TO_PK_BITS #endif #if GNUTLS_VERSION_NUMBER < 0x030103 && !defined(DISABLE_OCSP) # warning "GnuTLS library version too old; define DISABLE_OCSP in Makefile" # define DISABLE_OCSP #endif +#if GNUTLS_VERSION_NUMBER < 0x020a00 && !defined(DISABLE_EVENT) +# warning "GnuTLS library version too old; tls:cert event unsupported" +# define DISABLE_EVENT +#endif +#if GNUTLS_VERSION_NUMBER >= 0x030306 +# define SUPPORT_CA_DIR +#else +# undef SUPPORT_CA_DIR +#endif +#if GNUTLS_VERSION_NUMBER >= 0x030014 +# define SUPPORT_SYSDEFAULT_CABUNDLE +#endif #ifndef DISABLE_OCSP # include @@ -66,11 +79,7 @@ Changes: /* Values for verify_requirement */ enum peer_verify_requirement - { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED -#ifdef EXPERIMENTAL_CERTNAMES - ,VERIFY_WITHHOST -#endif - }; + { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED }; /* This holds most state for server or client; with this, we can set up an outbound TLS-enabled connection in an ACL callout, while not stomping all @@ -108,13 +117,13 @@ typedef struct exim_gnutls_state { uschar *exp_tls_certificate; uschar *exp_tls_privatekey; - uschar *exp_tls_sni; uschar *exp_tls_verify_certificates; uschar *exp_tls_crl; uschar *exp_tls_require_ciphers; uschar *exp_tls_ocsp_file; -#ifdef EXPERIMENTAL_CERTNAMES - uschar *exp_tls_verify_cert_hostnames; + const uschar *exp_tls_verify_cert_hostnames; +#ifndef DISABLE_EVENT + uschar *event_action; #endif tls_support *tlsp; /* set in tls_init() */ @@ -131,7 +140,8 @@ static const exim_gnutls_state_st exim_gnutls_state_init = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, -#ifdef EXPERIMENTAL_CERTNAMES + NULL, +#ifndef DISABLE_EVENT NULL, #endif NULL, @@ -145,7 +155,9 @@ context we're currently dealing with" pointer and rely upon being single-threaded to keep from processing data on an inbound TLS connection while talking to another TLS connection for an outbound check. This does mean that there's no way for heart-beats to be responded to, for the duration of the -second connection. */ +second connection. +XXX But see gnutls_session_get_ptr() +*/ static exim_gnutls_state_st state_server, state_client; @@ -165,6 +177,10 @@ static const char * const exim_default_gnutls_priority = "NORMAL"; static BOOL exim_gnutls_base_init_done = FALSE; +#ifndef DISABLE_OCSP +static BOOL gnutls_buggy_ocsp = FALSE; +#endif + /* ------------------------------------------------------------------------ */ /* macros */ @@ -175,18 +191,18 @@ static BOOL exim_gnutls_base_init_done = FALSE; the library logging; a value less than 0 disables the calls to set up logging callbacks. */ #ifndef EXIM_GNUTLS_LIBRARY_LOG_LEVEL -#define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1 +# define EXIM_GNUTLS_LIBRARY_LOG_LEVEL -1 #endif #ifndef EXIM_CLIENT_DH_MIN_BITS -#define EXIM_CLIENT_DH_MIN_BITS 1024 +# define EXIM_CLIENT_DH_MIN_BITS 1024 #endif /* With GnuTLS 2.12.x+ we have gnutls_sec_param_to_pk_bits() with which we can ask for a bit-strength. Without that, we stick to the constant we had before, for now. */ #ifndef EXIM_SERVER_DH_BITS_PRE2_12 -#define EXIM_SERVER_DH_BITS_PRE2_12 1024 +# define EXIM_SERVER_DH_BITS_PRE2_12 1024 #endif #define exim_gnutls_err_check(Label) do { \ @@ -257,7 +273,7 @@ tls_error(const uschar *prefix, const char *msg, const host_item *host) { if (host) { - log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s)%s%s", + log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection (%s)%s%s", host->name, host->address, prefix, msg ? ": " : "", msg ? msg : ""); return FAIL; } @@ -266,6 +282,7 @@ else uschar *conn_info = smtp_get_connection_info(); if (Ustrncmp(conn_info, US"SMTP ", 5) == 0) conn_info += 5; + /* I'd like to get separated H= here, but too hard for now */ log_write(0, LOG_MAIN, "TLS error on %s (%s)%s%s", conn_info, prefix, msg ? ": " : "", msg ? msg : ""); return DEFER; @@ -323,7 +340,7 @@ tls_error(when, msg, state->host); } while (0) static int -import_cert(const gnutls_datum * cert, gnutls_x509_crt_t * crtp) +import_cert(const gnutls_datum_t * cert, gnutls_x509_crt_t * crtp) { int rc; @@ -397,7 +414,7 @@ if (rc) { } else { old_pool = store_pool; store_pool = POOL_PERM; - tls_channelbinding_b64 = auth_b64encode(channel.data, (int)channel.size); + tls_channelbinding_b64 = b64encode(channel.data, (int)channel.size); store_pool = old_pool; DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n"); } @@ -409,7 +426,7 @@ tlsp->sni = state->received_sni; /* record our certificate */ { - const gnutls_datum * cert = gnutls_certificate_get_ours(state->session); + const gnutls_datum_t * cert = gnutls_certificate_get_ours(state->session); gnutls_x509_crt_t crt; tlsp->ourcert = cert && import_cert(cert, &crt)==0 ? crt : NULL; @@ -441,7 +458,7 @@ init_server_dh(void) { int fd, rc; unsigned int dh_bits; -gnutls_datum m; +gnutls_datum_t m; uschar filename_buf[PATH_MAX]; uschar *filename = NULL; size_t sz; @@ -549,8 +566,7 @@ if (fd >= 0) (void)close(fd); return tls_error(US"TLS cache not a file", NULL, NULL); } - fp = fdopen(fd, "rb"); - if (!fp) + if (!(fp = fdopen(fd, "rb"))) { saved_errno = errno; (void)close(fd); @@ -559,14 +575,12 @@ if (fd >= 0) } m.size = statbuf.st_size; - m.data = malloc(m.size); - if (m.data == NULL) + if (!(m.data = malloc(m.size))) { fclose(fp); return tls_error(US"malloc failed", strerror(errno), NULL); } - sz = fread(m.data, m.size, 1, fp); - if (!sz) + if (!(sz = fread(m.data, m.size, 1, fp))) { saved_errno = errno; fclose(fp); @@ -648,9 +662,9 @@ if (rc < 0) if (rc != GNUTLS_E_SHORT_MEMORY_BUFFER) exim_gnutls_err_check(US"gnutls_dh_params_export_pkcs3(NULL) sizing"); m.size = sz; - m.data = malloc(m.size); - if (m.data == NULL) + if (!(m.data = malloc(m.size))) return tls_error(US"memory allocation failed", strerror(errno), NULL); + /* 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); @@ -693,6 +707,74 @@ return OK; +/* Create and install a selfsigned certificate, for use in server mode */ + +static int +tls_install_selfsign(exim_gnutls_state_st * state) +{ +gnutls_x509_crt_t cert = NULL; +time_t now; +gnutls_x509_privkey_t pkey = NULL; +const uschar * where; +int rc; + +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"; +if ((rc = gnutls_x509_privkey_generate(pkey, GNUTLS_PK_RSA, +#ifdef SUPPORT_PARAM_TO_PK_BITS + gnutls_sec_param_to_pk_bits(GNUTLS_PK_RSA, GNUTLS_SEC_PARAM_LOW), +#else + 1024, +#endif + 0))) + goto err; + +where = US"configuring cert"; +now = 0; +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_key(cert, pkey)) + + || (rc = gnutls_x509_crt_set_dn_by_oid(cert, + GNUTLS_OID_X520_COUNTRY_NAME, 0, "UK", 2)) + || (rc = gnutls_x509_crt_set_dn_by_oid(cert, + GNUTLS_OID_X520_ORGANIZATION_NAME, 0, "Exim Developers", 15)) + || (rc = gnutls_x509_crt_set_dn_by_oid(cert, + GNUTLS_OID_X520_COMMON_NAME, 0, + smtp_active_hostname, Ustrlen(smtp_active_hostname))) + ) + goto err; + +where = US"signing cert"; +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))) + goto err; + +rc = OK; + +out: + if (cert) gnutls_x509_crt_deinit(cert); + if (pkey) gnutls_x509_privkey_deinit(pkey); + return rc; + +err: + rc = tls_error(where, gnutls_strerror(rc), NULL); + goto out; +} + + + + /************************************************* * Variables re-expanded post-SNI * *************************************************/ @@ -725,7 +807,6 @@ int cert_count; /* We check for tls_sni *before* expansion. */ if (!host) /* server */ - { if (!state->received_sni) { if (state->tls_certificate && @@ -746,7 +827,6 @@ if (!host) /* server */ 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(US"gnutls_certificate_allocate_credentials"); @@ -763,14 +843,13 @@ if (!expand_check_tlsvar(tls_certificate)) /* certificate is mandatory in server, optional in client */ -if ((state->exp_tls_certificate == NULL) || - (*state->exp_tls_certificate == '\0')) - { +if ( !state->exp_tls_certificate + || !*state->exp_tls_certificate + ) if (!host) - return tls_error(US"no TLS server certificate is specified", NULL, NULL); + return tls_install_selfsign(state); else DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n"); - } if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey)) return DEFER; @@ -790,9 +869,9 @@ if (state->exp_tls_certificate && *state->exp_tls_certificate) 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)) + 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"); } @@ -800,7 +879,6 @@ if (state->exp_tls_certificate && *state->exp_tls_certificate) { DEBUG(D_tls) debug_printf("TLS SNI: have a changed cert/key pair.\n"); } - } rc = gnutls_certificate_set_x509_key_file(state->x509_cred, CS state->exp_tls_certificate, CS state->exp_tls_privatekey, @@ -819,18 +897,25 @@ if ( !host /* server */ && tls_ocsp_file ) { - if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", - &state->exp_tls_ocsp_file)) - return DEFER; + if (gnutls_buggy_ocsp) + { + DEBUG(D_tls) debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); + } + else + { + if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", + &state->exp_tls_ocsp_file)) + return DEFER; - /* 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. */ + /* 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->x509_cred, - server_ocsp_stapling_cb, state->exp_tls_ocsp_file); + gnutls_certificate_set_ocsp_status_request_function(state->x509_cred, + server_ocsp_stapling_cb, state->exp_tls_ocsp_file); - DEBUG(D_tls) debug_printf("Set OCSP response file %s\n", &state->exp_tls_ocsp_file); + DEBUG(D_tls) debug_printf("OCSP response file = %s\n", state->exp_tls_ocsp_file); + } } #endif @@ -845,6 +930,10 @@ if (state->tls_verify_certificates && *state->tls_verify_certificates) { if (!expand_check_tlsvar(tls_verify_certificates)) return DEFER; +#ifndef SUPPORT_SYSDEFAULT_CABUNDLE + 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)) return DEFER; @@ -865,46 +954,65 @@ else return OK; } -if (Ustat(state->exp_tls_verify_certificates, &statbuf) < 0) +#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 { - log_write(0, LOG_MAIN|LOG_PANIC, "could not stat %s " - "(tls_verify_certificates): %s", state->exp_tls_verify_certificates, - strerror(errno)); - return DEFER; - } + 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; + } -/* 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 messsaging ... */ -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; - } +#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); + 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; + 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->x509_cred, + CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM) + : +#endif + gnutls_certificate_set_x509_trust_file(state->x509_cred, + CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM); } -cert_count = gnutls_certificate_set_x509_trust_file(state->x509_cred, - CS state->exp_tls_verify_certificates, GNUTLS_X509_FMT_PEM); if (cert_count < 0) { rc = cert_count; - exim_gnutls_err_check(US"gnutls_certificate_set_x509_trust_file"); + exim_gnutls_err_check(US"setting certificate trust"); } DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", cert_count); @@ -976,6 +1084,38 @@ return OK; * Initialize for GnuTLS * *************************************************/ + +#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. @@ -1039,6 +1179,11 @@ if (!exim_gnutls_base_init_done) } #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; } @@ -1086,15 +1231,15 @@ if (rc != OK) return rc; /* set SNI in client, only */ if (host) { - if (!expand_check(state->tlsp->sni, US"tls_out_sni", &state->exp_tls_sni)) + if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni)) return DEFER; - if (state->exp_tls_sni && *state->exp_tls_sni) + if (state->tlsp->sni && *state->tlsp->sni) { DEBUG(D_tls) - debug_printf("Setting TLS client SNI to \"%s\"\n", state->exp_tls_sni); - sz = Ustrlen(state->exp_tls_sni); + 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->exp_tls_sni, sz); + GNUTLS_NAME_DNS, state->tlsp->sni, sz); exim_gnutls_err_check(US"gnutls_server_name_set"); } } @@ -1194,7 +1339,7 @@ static int peer_status(exim_gnutls_state_st *state) { uschar cipherbuf[256]; -const gnutls_datum *cert_list; +const gnutls_datum_t *cert_list; int old_pool, rc; unsigned int cert_list_size = 0; gnutls_protocol_t protocol; @@ -1360,25 +1505,27 @@ if (rc < 0 || else { -#ifdef EXPERIMENTAL_CERTNAMES - if (state->verify_requirement == VERIFY_WITHHOST) + if (state->exp_tls_verify_cert_hostnames) { int sep = 0; - uschar * list = state->exp_tls_verify_cert_hostnames; + const uschar * list = state->exp_tls_verify_cert_hostnames; uschar * name; - while (name = string_nextinlist(&list, &sep, NULL, 0)) + while ((name = string_nextinlist(&list, &sep, NULL, 0))) if (gnutls_x509_crt_check_hostname(state->tlsp->peercert, CS name)) break; if (!name) { DEBUG(D_tls) debug_printf("TLS certificate verification failed: cert name mismatch\n"); - gnutls_alert_send(state->session, - GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); - return FALSE; + if (state->verify_requirement >= VERIFY_REQUIRED) + { + gnutls_alert_send(state->session, + GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); + return FALSE; + } + return TRUE; } } -#endif state->peer_cert_verified = TRUE; DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=\"%s\"\n", state->peerdn ? state->peerdn : US""); @@ -1513,6 +1660,54 @@ return 0; #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. +*/ + +static int +verify_cb(gnutls_session_t session) +{ +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); + +cert_list = gnutls_certificate_get_peers(session, &cert_list_size); +if (cert_list) + while (cert_list_size--) + { + rc = import_cert(&cert_list[cert_list_size], &crt); + if (rc != 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 @@ -1589,6 +1784,15 @@ else gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_IGNORE); } +#ifndef DISABLE_EVENT +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); + } +#endif + /* Register SNI handling; always, even if not in tls_certificate, so that the expansion variable $tls_sni is always available. */ @@ -1611,32 +1815,36 @@ if (!state->tlsp->on_connect) that the GnuTLS library doesn't. */ gnutls_transport_set_ptr2(state->session, - (gnutls_transport_ptr)(long) fileno(smtp_in), - (gnutls_transport_ptr)(long) fileno(smtp_out)); + (gnutls_transport_ptr_t)(long) fileno(smtp_in), + (gnutls_transport_ptr_t)(long) fileno(smtp_out)); state->fd_in = fileno(smtp_in); state->fd_out = fileno(smtp_out); sigalrm_seen = FALSE; if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); do - { rc = gnutls_handshake(state->session); - } while ((rc == GNUTLS_E_AGAIN) || - (rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen)); +while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen); alarm(0); if (rc != GNUTLS_E_SUCCESS) { - tls_error(US"gnutls_handshake", - sigalrm_seen ? "timed out" : gnutls_strerror(rc), NULL); /* It seems that, except in the case of a timeout, we have to close the connection right here; otherwise if the other end is running OpenSSL it hangs until the server times out. */ - if (!sigalrm_seen) + if (sigalrm_seen) + tls_error(US"gnutls_handshake", "timed out", NULL); + else { + tls_error(US"gnutls_handshake", gnutls_strerror(rc), NULL); + gnutls_alert_send_appropriate(state->session, rc); + millisleep(500); + shutdown(fileno(smtp_out), SHUT_WR); + for (rc = 1024; fgetc(smtp_in) != EOF && rc > 0; ) rc--; /* drain skt */ (void)fclose(smtp_out); (void)fclose(smtp_in); + smtp_out = smtp_in = NULL; } return FAIL; @@ -1661,8 +1869,7 @@ if ( state->verify_requirement != VERIFY_NONE /* Figure out peer DN, and if authenticated, etc. */ -rc = peer_status(state); -if (rc != OK) return rc; +if ((rc = peer_status(state)) != OK) return rc; /* Sets various Exim expansion variables; always safe within server */ @@ -1674,6 +1881,7 @@ and initialize appropriately. */ state->xfer_buffer = store_malloc(ssl_xfer_buffer_size); receive_getc = tls_getc; +receive_get_cache = tls_get_cache; receive_ungetc = tls_ungetc; receive_feof = tls_feof; receive_ferror = tls_ferror; @@ -1685,6 +1893,25 @@ return OK; +static void +tls_client_setup_hostname_checks(host_item * host, exim_gnutls_state_st * state, + smtp_transport_options_block * ob) +{ +if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK) + { + state->exp_tls_verify_cert_hostnames = +#ifdef SUPPORT_I18N + string_domain_utf8_to_alabel(host->name, NULL); +#else + host->name; +#endif + DEBUG(D_tls) + debug_printf("TLS: server cert verification includes hostname: \"%s\".\n", + state->exp_tls_verify_cert_hostnames); + } +} + + /************************************************* * Start a TLS session in a client * *************************************************/ @@ -1695,7 +1922,7 @@ Arguments: fd the fd of the connection host connected host (for messages) addr the first address (not used) - ob smtp transport options + tb transport (always smtp) Returns: OK/DEFER/FAIL (because using common functions), but for a client, DEFER and FAIL have the same meaning @@ -1704,18 +1931,22 @@ Returns: OK/DEFER/FAIL (because using common functions), int tls_client_start(int fd, host_item *host, address_item *addr ARG_UNUSED, - void *v_ob) + transport_instance *tb +#ifdef EXPERIMENTAL_DANE + , dns_answer * unused_tlsa_dnsa +#endif + ) { -smtp_transport_options_block *ob = v_ob; +smtp_transport_options_block *ob = + (smtp_transport_options_block *)tb->options_block; int rc; const char *error; exim_gnutls_state_st *state = NULL; #ifndef DISABLE_OCSP -BOOL require_ocsp = verify_check_this_host(&ob->hosts_require_ocsp, - NULL, host->name, host->address, NULL) == OK; +BOOL require_ocsp = + verify_check_given_host(&ob->hosts_require_ocsp, host) == OK; BOOL request_ocsp = require_ocsp ? TRUE - : verify_check_this_host(&ob->hosts_request_ocsp, - NULL, host->name, host->address, NULL) == OK; + : verify_check_given_host(&ob->hosts_request_ocsp, host) == OK; #endif DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", fd); @@ -1742,43 +1973,26 @@ if ((rc = tls_init(host, ob->tls_certificate, ob->tls_privatekey, gnutls_dh_set_prime_bits(state->session, dh_min_bits); } -/* Stick to the old behaviour for compatibility if tls_verify_certificates is +/* Stick to the old behaviour for compatibility if tls_verify_certificates is 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 */ -if (( state->exp_tls_verify_certificates - && !ob->tls_verify_hosts - && !ob->tls_try_verify_hosts - ) - || - verify_check_host(&ob->tls_verify_hosts) == OK +if ( ( state->exp_tls_verify_certificates + && !ob->tls_verify_hosts + && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) + ) + || verify_check_given_host(&ob->tls_verify_hosts, host) == OK ) { -#ifdef EXPERIMENTAL_CERTNAMES - if (ob->tls_verify_cert_hostnames) - { - DEBUG(D_tls) - debug_printf("TLS: server cert incl. hostname verification required.\n"); - state->verify_requirement = VERIFY_WITHHOST; - if (!expand_check(ob->tls_verify_cert_hostnames, - US"tls_verify_cert_hostnames", - &state->exp_tls_verify_cert_hostnames)) - return FAIL; - if (state->exp_tls_verify_cert_hostnames) - DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", - state->exp_tls_verify_cert_hostnames); - } - else -#endif - { - DEBUG(D_tls) - debug_printf("TLS: server certificate verification required.\n"); - state->verify_requirement = VERIFY_REQUIRED; - } + tls_client_setup_hostname_checks(host, state, ob); + DEBUG(D_tls) + debug_printf("TLS: server certificate verification required.\n"); + state->verify_requirement = VERIFY_REQUIRED; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); } -else if (verify_check_host(&ob->tls_try_verify_hosts) == OK) +else if (verify_check_given_host(&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"); state->verify_requirement = VERIFY_OPTIONAL; @@ -1805,7 +2019,16 @@ if (request_ocsp) } #endif -gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr)(long) fd); +#ifndef DISABLE_EVENT +if (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); + } +#endif + +gnutls_transport_set_ptr(state->session, (gnutls_transport_ptr_t)(long) fd); state->fd_in = fd; state->fd_out = fd; @@ -1822,8 +2045,13 @@ do alarm(0); if (rc != GNUTLS_E_SUCCESS) - return tls_error(US"gnutls_handshake", - sigalrm_seen ? "timed out" : gnutls_strerror(rc), state->host); + if (sigalrm_seen) + { + gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_USER_CANCELED); + return tls_error(US"gnutls_handshake", "timed out", state->host); + } + else + return tls_error(US"gnutls_handshake", gnutls_strerror(rc), state->host); DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n"); @@ -1900,7 +2128,7 @@ if (!state->tlsp || state->tlsp->active < 0) return; /* TLS was not active */ if (shutdown) { - DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS\n"); + DEBUG(D_tls) debug_printf("tls_close() from '%s': shutting down TLS\n"); gnutls_bye(state->session, GNUTLS_SHUT_WR); } @@ -1950,15 +2178,24 @@ if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) ssl_xfer_buffer_size); alarm(0); - /* A zero-byte return appears to mean that the TLS session has been + /* Timeouts do not get this far; see command_timeout_handler(). + A zero-byte return appears to mean that the TLS session has been closed down, not that the socket itself has been closed down. Revert to non-TLS handling. */ - if (inbytes == 0) + if (sigalrm_seen) + { + DEBUG(D_tls) debug_printf("Got tls read timeout\n"); + state->xfer_error = 1; + return EOF; + } + + else if (inbytes == 0) { DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); receive_getc = smtp_getc; + receive_get_cache = smtp_get_cache; receive_ungetc = smtp_ungetc; receive_feof = smtp_feof; receive_ferror = smtp_ferror; @@ -1997,6 +2234,17 @@ if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) return state->xfer_buffer[state->xfer_buffer_lwm++]; } +void +tls_get_cache() +{ +#ifndef DISABLE_DKIM +exim_gnutls_state_st * state = &state_server; +int n = state->xfer_buffer_hwm - state->xfer_buffer_lwm; +if (n > 0) + dkim_exim_verify_feed(state->xfer_buffer+state->xfer_buffer_lwm, n); +#endif +} +