X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/3674140cddab39c76f4cd360a4b5c102e94d4759..dec766a1977250758eb7a3e127e079a9271afd89:/src/src/tls-gnu.c diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index 1fee6c107..e0ac6a546 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 - 2017 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ /* See the file NOTICE for conditions of use and distribution. */ /* Copyright (c) Phil Pennock 2012 */ @@ -66,8 +66,17 @@ require current GnuTLS, then we'll drop support for the ancient libraries). #if GNUTLS_VERSION_NUMBER >= 0x030506 && !defined(DISABLE_OCSP) # define SUPPORT_SRV_OCSP_STACK #endif -#if GNUTLS_VERSION_NUMBER >= 0x030000 && defined(EXPERIMENTAL_DANE) -# define SUPPORT_DANE + +#ifdef SUPPORT_DANE +# if GNUTLS_VERSION_NUMBER >= 0x030000 +# define DANESSL_USAGE_DANE_TA 2 +# define DANESSL_USAGE_DANE_EE 3 +# else +# error GnuTLS version too early for DANE +# endif +# if GNUTLS_VERSION_NUMBER < 0x999999 +# define GNUTLS_BROKEN_DANE_VALIDATION +# endif #endif #ifndef DISABLE_OCSP @@ -1600,24 +1609,91 @@ else dane_state_t s; dane_query_t r; - const gnutls_datum_t * certlist; uint lsize; + const gnutls_datum_t * certlist = + gnutls_certificate_get_peers(state->session, &lsize); + int usage = tls_out.tlsa_usage; + +# ifdef GNUTLS_BROKEN_DANE_VALIDATION + /* Split the TLSA records into two sets, TA and EE selectors. Run the + dane-verification separately so that we know which selector verified; + then we know whether to do CA-chain-verification and name-verification + (needed for TA but not EE). */ + + if (usage == ((1<dane_data_len[nrec]; ) nrec++; + nrec++; + + dd = store_get(nrec * sizeof(uschar *)); + ddl = store_get(nrec * sizeof(int)); + nrec--; + + if ((rc = dane_state_init(&s, 0))) + goto tlsa_prob; + + for (usage = DANESSL_USAGE_DANE_EE; + usage >= DANESSL_USAGE_DANE_TA; usage--) + { /* take records with this usage */ + for (j = i = 0; i < nrec; i++) + if (state->dane_data[i][0] == usage) + { + dd[j] = state->dane_data[i]; + ddl[j++] = state->dane_data_len[i]; + } + if (j) + { + dd[j] = NULL; + ddl[j] = 0; + + if ((rc = dane_raw_tlsa(s, &r, (char * const *)dd, ddl, 1, 0))) + goto tlsa_prob; + + if ((rc = dane_verify_crt_raw(s, certlist, lsize, + gnutls_certificate_type_get(state->session), + r, 0, + usage == DANESSL_USAGE_DANE_EE + ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0, + &verify))) + { + DEBUG(D_tls) + debug_printf("TLSA record problem: %s\n", dane_strerror(rc)); + } + else if (verify == 0) /* verification passed */ + { + usage = 1 << usage; + break; + } + } + } - certlist = gnutls_certificate_get_peers(state->session, &lsize); - - if ( (rc = dane_state_init(&s, 0)) - || (rc = dane_raw_tlsa(s, &r, state->dane_data, state->dane_data_len, - 1, 0)) - || (rc = dane_verify_crt_raw(s, certlist, lsize, - gnutls_certificate_type_get(state->session), - r, 0, 0, &verify)) - ) - + if (rc) goto tlsa_prob; + } + else +# endif { - *errstr = string_sprintf("TLSA record problem: %s", dane_strerror(rc)); - goto badcert; + if ( (rc = dane_state_init(&s, 0)) + || (rc = dane_raw_tlsa(s, &r, state->dane_data, state->dane_data_len, + 1, 0)) + || (rc = dane_verify_crt_raw(s, certlist, lsize, + gnutls_certificate_type_get(state->session), + r, 0, +# ifdef GNUTLS_BROKEN_DANE_VALIDATION + usage == (1 << DANESSL_USAGE_DANE_EE) + ? DANE_VFLAG_ONLY_CHECK_EE_USAGE : 0, +# else + 0, +# endif + &verify)) + ) + goto tlsa_prob; } - if (verify != 0) + + if (verify != 0) /* verification failed */ { gnutls_datum_t str; (void) dane_verification_status_print(verify, &str, 0); @@ -1626,11 +1702,12 @@ else } state->peer_dane_verified = TRUE; - /* If there were only EE-mode TLSA records present, no checks on cert anchor - valididation or cert names are required. For a TA record only, or a mixed - set, do them (we cannot tell if an EE record worked). */ +# ifdef GNUTLS_BROKEN_DANE_VALIDATION + /* If a TA-mode TLSA record was used for verification we must additionally + verify the CA chain and the cert name. For EE-mode, skip it. */ - if (!(tls_out.tlsa_usage & (1 << 2))) + if (usage & (1 << DANESSL_USAGE_DANE_EE)) +# endif { state->peer_cert_verified = TRUE; goto goodcert; @@ -1688,6 +1765,11 @@ goodcert: state->tlsp->peerdn = state->peerdn; return TRUE; +#ifdef SUPPORT_DANE +tlsa_prob: + *errstr = string_sprintf("TLSA record problem: %s", dane_strerror(rc)); +#endif + badcert: gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); return FALSE; @@ -2112,8 +2194,10 @@ for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS), i = 0; DEBUG(D_tls) debug_printf("TLSA: %d %d %d size %d\n", usage, sel, type, rr->size); - if (usage != 2 && usage != 3) continue; - if (sel != 0 && sel != 1) continue; + if ( (usage != DANESSL_USAGE_DANE_TA && usage != DANESSL_USAGE_DANE_EE) + || (sel != 0 && sel != 1) + ) + continue; switch(type) { case 0: /* Full: cannot check at present */ @@ -2169,7 +2253,7 @@ int tls_client_start(int fd, host_item *host, address_item *addr ARG_UNUSED, transport_instance * tb, -#ifdef EXPERIMENTAL_DANE +#ifdef SUPPORT_DANE dns_answer * tlsa_dnsa, #endif uschar ** errstr) @@ -2284,10 +2368,8 @@ DEBUG(D_tls) debug_printf("about to gnutls_handshake\n"); sigalrm_seen = FALSE; alarm(ob->command_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) @@ -2360,12 +2442,15 @@ return OK; daemon, to shut down the TLS library, without actually doing a shutdown (which would tamper with the TLS session in the parent process). -Arguments: TRUE if gnutls_bye is to be called +Arguments: + shutdown 1 if TLS close-alert is to be sent, + 2 if also response to be waited for + Returns: nothing */ void -tls_close(BOOL is_server, BOOL shutdown) +tls_close(BOOL is_server, int shutdown) { exim_gnutls_state_st *state = is_server ? &state_server : &state_client; @@ -2373,8 +2458,12 @@ 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"); - gnutls_bye(state->session, GNUTLS_SHUT_WR); + DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n", + shutdown > 1 ? " (with response-wait)" : ""); + + alarm(2); + gnutls_bye(state->session, shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR); + alarm(0); } gnutls_deinit(state->session); @@ -2382,9 +2471,10 @@ gnutls_certificate_free_credentials(state->x509_cred); state->tlsp->active = -1; +if (state->xfer_buffer) store_free(state->xfer_buffer); memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); -if ((state_server.session == NULL) && (state_client.session == NULL)) +if (!state_server.session && !state_client.session) { gnutls_global_deinit(); exim_gnutls_base_init_done = FALSE; @@ -2403,6 +2493,7 @@ ssize_t inbytes; DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, %u)\n", state->session, state->xfer_buffer, ssl_xfer_buffer_size); +sigalrm_seen = FALSE; if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); inbytes = gnutls_record_recv(state->session, state->xfer_buffer, MIN(ssl_xfer_buffer_size, lim));