X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/9723f9667322bf96db786fa49d53139a48fabc5e..12d95aa62042377fc9f603245a17a43142972447:/src/src/tls-gnu.c diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index 35816cd60..423c3a23d 100644 --- a/src/src/tls-gnu.c +++ b/src/src/tls-gnu.c @@ -39,6 +39,7 @@ require current GnuTLS, then we'll drop support for the ancient libraries). #include /* man-page is incorrect, gnutls_rnd() is not in gnutls.h: */ #include + /* needed to disable PKCS11 autoload unless requested */ #if GNUTLS_VERSION_NUMBER >= 0x020c00 # include @@ -60,9 +61,18 @@ require current GnuTLS, then we'll drop support for the ancient libraries). #if GNUTLS_VERSION_NUMBER >= 0x030014 # define SUPPORT_SYSDEFAULT_CABUNDLE #endif +#if GNUTLS_VERSION_NUMBER >= 0x030104 +# define GNUTLS_CERT_VFY_STATUS_PRINT +#endif #if GNUTLS_VERSION_NUMBER >= 0x030109 # define SUPPORT_CORK #endif +#if GNUTLS_VERSION_NUMBER >= 0x03010a +# define SUPPORT_GNUTLS_SESS_DESC +#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 @@ -79,6 +89,12 @@ require current GnuTLS, then we'll drop support for the ancient libraries). # endif #endif +#ifdef EXPERIMENTAL_TLS_RESUME +# if GNUTLS_VERSION_NUMBER < 0x030603 +# error GNUTLS version too early for session-resumption +# endif +#endif + #ifndef DISABLE_OCSP # include #endif @@ -86,6 +102,20 @@ 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) +{ +# ifdef EXPERIMENTAL_TLS_RESUME +builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING ); +# endif +} +#else + + /* GnuTLS 2 vs 3 GnuTLS 3 only: @@ -124,8 +154,8 @@ typedef struct exim_gnutls_state { BOOL peer_dane_verified; BOOL trigger_sni_changes; BOOL have_set_peerdn; - const struct host_item *host; - gnutls_x509_crt_t peercert; + const struct host_item *host; /* NULL if server */ + gnutls_x509_crt_t peercert; uschar *peerdn; uschar *ciphersuite; uschar *received_sni; @@ -161,45 +191,9 @@ typedef struct exim_gnutls_state { } 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 @@ -213,7 +207,7 @@ second connection. XXX But see gnutls_session_get_ptr() */ -static exim_gnutls_state_st state_server, state_client; +static exim_gnutls_state_st state_server; /* 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 @@ -221,11 +215,9 @@ 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 const int ssl_session_timeout = 200; +static int ssl_session_timeout = 7200; /* Two hours */ -static const char * const exim_default_gnutls_priority = "NORMAL"; +static const uschar * const exim_default_gnutls_priority = US"NORMAL"; /* Guard library core initialisation */ @@ -235,6 +227,9 @@ static BOOL exim_gnutls_base_init_done = FALSE; static BOOL gnutls_buggy_ocsp = FALSE; #endif +#ifdef EXPERIMENTAL_TLS_RESUME +static gnutls_datum_t server_sessticket_key; +#endif /* ------------------------------------------------------------------------ */ /* macros */ @@ -243,8 +238,10 @@ 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 @@ -260,11 +257,6 @@ 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), gnutls_strerror(rc), host, errstr); \ - } while (0) - #define expand_check_tlsvar(Varname, errstr) \ expand_check(state->Varname, US #Varname, &state->exp_##Varname, errstr) @@ -302,6 +294,24 @@ static int server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, +/* Daemon one-time initialisation */ +void +tls_daemon_init(void) +{ +#ifdef EXPERIMENTAL_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 */ @@ -328,15 +338,28 @@ Returns: OK/DEFER/FAIL */ static int -tls_error(const uschar *prefix, const char *msg, const host_item *host, +tls_error(const uschar *prefix, const uschar *msg, const host_item *host, uschar ** errstr) { if (errstr) - *errstr = string_sprintf("(%s)%s%s", prefix, msg ? ": " : "", msg ? msg : ""); + *errstr = string_sprintf("(%s)%s%s", prefix, msg ? ": " : "", msg ? msg : US""); return host ? FAIL : DEFER; } +static int +tls_error_gnu(const uschar *prefix, int err, const host_item *host, + uschar ** errstr) +{ +return tls_error(prefix, US gnutls_strerror(err), host, 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); +} /************************************************* @@ -349,7 +372,7 @@ 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 */ @@ -357,14 +380,14 @@ Returns: nothing static void record_io_error(exim_gnutls_state_st *state, int rc, uschar *when, uschar *text) { -const char * msg; +const uschar * msg; uschar * errstr; if (rc == GNUTLS_E_FATAL_ALERT_RECEIVED) - msg = CS string_sprintf("%s: %s", US gnutls_strerror(rc), + msg = string_sprintf("A TLS fatal alert has been received: %s", US gnutls_alert_get_name(gnutls_alert_get(state->session))); else - msg = gnutls_strerror(rc); + msg = US gnutls_strerror(rc); (void) tls_error(when, msg, state->host, &errstr); @@ -440,7 +463,6 @@ 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; @@ -448,13 +470,8 @@ gnutls_datum_t channel; #endif tls_support * tlsp = state->tlsp; -tlsp->active = state->fd_out; - -cipher = gnutls_cipher_get(state->session); -/* returns size in "bytes" */ -tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; - -tlsp->cipher = state->ciphersuite; +tlsp->active.sock = state->fd_out; +tlsp->active.tls_ctx = state; DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite); @@ -470,16 +487,16 @@ tls_channelbinding_b64 = NULL; #ifdef HAVE_GNUTLS_SESSION_CHANNEL_BINDING channel.data = NULL; channel.size = 0; -rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel); -if (rc) { - DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); -} else { +if ((rc = gnutls_session_channel_binding(state->session, GNUTLS_CB_TLS_UNIQUE, &channel))) + { DEBUG(D_tls) debug_printf("Channel binding error: %s\n", gnutls_strerror(rc)); } +else + { old_pool = store_pool; store_pool = POOL_PERM; - tls_channelbinding_b64 = b64encode(channel.data, (int)channel.size); + tls_channelbinding_b64 = b64encode(CUS channel.data, (int)channel.size); store_pool = old_pool; DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage.\n"); -} + } #endif /* peercert is set in peer_status() */ @@ -526,13 +543,12 @@ 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"); -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(US"gnutls_dh_params_init", rc, host, errstr); m.data = NULL; m.size = 0; @@ -556,19 +572,16 @@ else if (Ustrcmp(exp_tls_dhparam, "none") == 0) else if (exp_tls_dhparam[0] != '/') { if (!(m.data = US std_dh_prime_named(exp_tls_dhparam))) - return tls_error(US"No standard prime named", CS exp_tls_dhparam, NULL, errstr); + return tls_error(US"No standard prime named", exp_tls_dhparam, NULL, errstr); 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(US"gnutls_dh_params_import_pkcs3", rc, host, errstr); DEBUG(D_tls) debug_printf("Loaded fixed standard D-H parameters\n"); return OK; } @@ -576,8 +589,8 @@ 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", @@ -619,7 +632,7 @@ if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) { saved_errno = errno; (void)close(fd); - return tls_error(US"TLS cache stat failed", strerror(saved_errno), NULL, errstr); + return tls_error_sys(US"TLS cache stat failed", saved_errno, NULL, errstr); } if (!S_ISREG(statbuf.st_mode)) { @@ -630,28 +643,29 @@ if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) { saved_errno = errno; (void)close(fd); - return tls_error(US"fdopen(TLS cache stat fd) failed", - 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))) { fclose(fp); - return tls_error(US"malloc failed", 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", strerror(saved_errno), NULL, errstr); + 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"); + 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); } @@ -681,12 +695,12 @@ if (rc < 0) if ((PATH_MAX - Ustrlen(filename)) < 10) return tls_error(US"Filename too long to generate replacement", - CS filename, NULL, errstr); + filename, NULL, errstr); - temp_fn = string_copy(US "%s.XXXXXXX"); + temp_fn = string_copy(US"%s.XXXXXXX"); if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */ - return tls_error(US"Unable to open temp file", 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. @@ -707,8 +721,8 @@ 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(US"gnutls_dh_params_generate2", rc, host, 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 @@ -716,41 +730,41 @@ 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(US"gnutls_dh_params_export_pkcs3(NULL) sizing", + rc, host, errstr); m.size = sz; if (!(m.data = malloc(m.size))) - return tls_error(US"memory allocation failed", strerror(errno), NULL, errstr); + 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"); + 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); - return tls_error(US"TLS cache write D-H params failed", - strerror(errno), NULL, errstr); + return tls_error_sys(US"TLS cache write D-H params failed", + errno, NULL, errstr); } 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", - 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", 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), 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); } @@ -782,15 +796,18 @@ 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), +# ifndef GNUTLS_SEC_PARAM_MEDIUM +# define GNUTLS_SEC_PARAM_MEDIUM GNUTLS_SEC_PARAM_HIGH +# endif + gnutls_sec_param_to_pk_bits(GNUTLS_PK_RSA, GNUTLS_SEC_PARAM_MEDIUM), #else - 1024, + 2048, #endif 0))) goto err; where = US"configuring cert"; -now = 0; +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))) @@ -823,7 +840,7 @@ out: return rc; err: - rc = tls_error(where, gnutls_strerror(rc), NULL, errstr); + rc = tls_error_gnu(where, rc, NULL, errstr); goto out; } @@ -844,9 +861,9 @@ tls_add_certfile(exim_gnutls_state_st * state, const host_item * host, int rc = gnutls_certificate_set_x509_key_file(state->x509_cred, CS certfile, CS keyfile, GNUTLS_X509_FMT_PEM); if (rc < 0) - return tls_error( + return tls_error_gnu( string_sprintf("cert/key setup: cert=%s key=%s", certfile, keyfile), - gnutls_strerror(rc), host, errstr); + rc, host, errstr); return -rc; } @@ -905,8 +922,9 @@ if (!host) /* server */ 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"); +if ((rc = gnutls_certificate_allocate_credentials(&state->x509_cred))) + return tls_error_gnu(US"gnutls_certificate_allocate_credentials", + rc, host, errstr); #ifdef SUPPORT_SRV_OCSP_STACK gnutls_certificate_set_flags(state->x509_cred, GNUTLS_CERTIFICATE_API_V2); @@ -1003,12 +1021,12 @@ if (state->exp_tls_certificate && *state->exp_tls_certificate) or watch datestamp. */ # ifdef SUPPORT_SRV_OCSP_STACK - rc = gnutls_certificate_set_ocsp_status_request_function2( - state->x509_cred, gnutls_cert_index, - server_ocsp_stapling_cb, ofile); - - exim_gnutls_err_check(rc, - US"gnutls_certificate_set_ocsp_status_request_function2"); + 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 if (cnt++ > 0) { @@ -1125,26 +1143,30 @@ 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) - { - rc = cert_count; - exim_gnutls_err_check(rc, US"setting certificate trust"); - } -DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", cert_count); + return tls_error_gnu(US"setting certificate trust", cert_count, host, 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) { 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"); - } + if ((cert_count = gnutls_certificate_set_x509_crl_file(state->x509_cred, + CS state->exp_tls_crl, GNUTLS_X509_FMT_PEM)) < 0) + return tls_error_gnu(US"gnutls_certificate_set_x509_crl_file", + cert_count, host, errstr); + DEBUG(D_tls) debug_printf("Processed %d CRLs.\n", cert_count); } @@ -1184,17 +1206,15 @@ client-side params. */ if (!state->host) { if (!dh_server_params) - { - rc = init_server_dh(errstr); - if (rc != OK) return rc; - } + if ((rc = init_server_dh(errstr)) != OK) return rc; gnutls_certificate_set_dh_params(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->x509_cred))) + return tls_error_gnu(US"gnutls_credentials_set", rc, host, errstr); return OK; } @@ -1262,14 +1282,14 @@ tls_init( const uschar *crl, 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; +const char * errpos; +const uschar * p; if (!exim_gnutls_base_init_done) { @@ -1282,20 +1302,18 @@ if (!exim_gnutls_base_init_done) 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"); - } + if ((rc = gnutls_pkcs11_init(GNUTLS_PKCS11_FLAG_MANUAL, NULL))) + return tls_error_gnu(US"gnutls_pkcs11_init", rc, host, errstr); #endif - rc = gnutls_global_init(); - exim_gnutls_err_check(rc, US"gnutls_global_init"); + if ((rc = gnutls_global_init())) + return tls_error_gnu(US"gnutls_global_init", rc, host, errstr); #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 */ + /* arbitrarily chosen level; bump up to 9 for more */ gnutls_global_set_log_level(EXIM_GNUTLS_LIBRARY_LOG_LEVEL); } #endif @@ -1310,9 +1328,15 @@ if (!exim_gnutls_base_init_done) if (host) { - state = &state_client; + /* 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)); + store_pool = old_pool; + memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); - state->tlsp = &tls_out; + state->tlsp = tlsp; DEBUG(D_tls) debug_printf("initialising GnuTLS client session\n"); rc = gnutls_init(&state->session, GNUTLS_CLIENT); } @@ -1320,11 +1344,12 @@ else { state = &state_server; memcpy(state, &exim_gnutls_state_init, sizeof(exim_gnutls_state_init)); - state->tlsp = &tls_in; + state->tlsp = tlsp; DEBUG(D_tls) debug_printf("initialising GnuTLS server session\n"); rc = gnutls_init(&state->session, GNUTLS_SERVER); } -exim_gnutls_err_check(rc, US"gnutls_init"); +if (rc) + return tls_error_gnu(US"gnutls_init", rc, host, errstr); state->host = host; @@ -1357,9 +1382,9 @@ if (host) 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(US"gnutls_server_name_set", rc, host, errstr); } } else if (state->tls_sni) @@ -1372,39 +1397,35 @@ 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. */ -want_default_priorities = TRUE; - +p = NULL; 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) { - 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; + DEBUG(D_tls) debug_printf("GnuTLS session cipher/priority \"%s\"\n", p); } } -if (want_default_priorities) +if (!p) { + p = exim_default_gnutls_priority; 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_printf("GnuTLS using default session cipher/priority \"%s\"\n", p); } -exim_gnutls_err_check(rc, string_sprintf( - "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"", - p, errpos - CS p, errpos)); +if ((rc = gnutls_priority_init(&state->priority_cache, CCS p, &errpos))) + return tls_error_gnu(string_sprintf( + "gnutls_priority_init(%s) failed at offset %ld, \"%.6s..\"", + p, errpos - CS p, errpos), + rc, host, errstr); -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->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); @@ -1430,6 +1451,25 @@ 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. @@ -1456,10 +1496,10 @@ 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; @@ -1468,7 +1508,7 @@ gnutls_kx_algorithm_t kx; gnutls_mac_algorithm_t mac; gnutls_certificate_type_t ct; gnutls_x509_crt_t crt; -uschar *p, *dn_buf; +uschar * dn_buf; size_t sz; if (state->have_set_peerdn) @@ -1478,46 +1518,85 @@ 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 (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); + 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 = '-'; +#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); if (state->verify_requirement >= VERIFY_REQUIRED) return tls_error(US"certificate verification failed", - "no certificate received from peer", state->host, errstr); + US"no certificate received from peer", state->host, errstr); 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 char *ctn = 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) @@ -1533,7 +1612,7 @@ 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), gnutls_strerror(rc), state->host, errstr); \ + return tls_error_gnu((Label), rc, state->host, errstr); \ return OK; \ } \ } while (0) @@ -1587,12 +1666,14 @@ verify_certificate(exim_gnutls_state_st * state, uschar ** errstr) int rc; uint verify; +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; -*errstr = NULL; - -if ((rc = peer_status(state, errstr)) != OK) +if (rc != OK || !state->peerdn) { verify = GNUTLS_CERT_INVALID; *errstr = US"certificate not supplied"; @@ -1617,8 +1698,7 @@ else # 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). */ + then we know whether to do name-verification (needed for TA but not EE). */ if (usage == ((1<peer_dane_verified = TRUE; # 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. */ + verify the cert name (but not the CA chain). For EE-mode, skip it. */ if (usage & (1 << DANESSL_USAGE_DANE_EE)) # endif { - state->peer_cert_verified = TRUE; + state->peer_dane_verified = state->peer_cert_verified = TRUE; goto goodcert; } +# ifdef GNUTLS_BROKEN_DANE_VALIDATION + /* Assume that the name on the A-record is the one that should be matching + the cert. An alternate view is that the domain part of the email address + is also permissible. */ + + if (gnutls_x509_crt_check_hostname(state->tlsp->peercert, + CS state->host->name)) + { + state->peer_dane_verified = state->peer_cert_verified = TRUE; + goto goodcert; + } +# endif } -#endif +#endif /*SUPPORT_DANE*/ rc = gnutls_certificate_verify_peers2(state->session, &verify); } @@ -1724,8 +1815,24 @@ if (rc < 0 || verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED)) { state->peer_cert_verified = FALSE; if (!*errstr) + { +#ifdef GNUTLS_CERT_VFY_STATUS_PRINT + DEBUG(D_tls) + { + gnutls_datum_t txt; + + if (gnutls_certificate_verification_status_print(verify, + gnutls_certificate_type_get(state->session), &txt, 0) + == GNUTLS_E_SUCCESS) + { + debug_printf("%s\n", txt.data); + gnutls_free(txt.data); + } + } +#endif *errstr = verify & GNUTLS_CERT_REVOKED ? US"certificate revoked" : US"certificate invalid"; + } DEBUG(D_tls) debug_printf("TLS certificate verification failed (%s): peerdn=\"%s\"\n", @@ -1739,23 +1846,23 @@ if (rc < 0 || verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED)) else { - if (state->exp_tls_verify_cert_hostnames) + /* Client side, check the server's certificate name versus the name on the + A-record for the connection we made. What to do for server side - what name + to use for client? We document that there is no such checking for server + side. */ + + if ( state->exp_tls_verify_cert_hostnames + && !gnutls_x509_crt_check_hostname(state->tlsp->peercert, + CS state->exp_tls_verify_cert_hostnames) + ) { - int sep = 0; - const uschar * list = state->exp_tls_verify_cert_hostnames; - uschar * name; - 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"); - if (state->verify_requirement >= VERIFY_REQUIRED) - goto badcert; - return TRUE; - } + DEBUG(D_tls) + debug_printf("TLS certificate verification failed: cert name mismatch\n"); + if (state->verify_requirement >= VERIFY_REQUIRED) + goto badcert; + return TRUE; } + state->peer_cert_verified = TRUE; DEBUG(D_tls) debug_printf("TLS certificate verified: peerdn=\"%s\"\n", state->peerdn ? state->peerdn : US""); @@ -1767,7 +1874,8 @@ goodcert: #ifdef SUPPORT_DANE tlsa_prob: - *errstr = string_sprintf("TLSA record problem: %s", dane_strerror(rc)); + *errstr = string_sprintf("TLSA record problem: %s", + rc == DANE_E_REQUESTED_DATA_NOT_AVAILABLE ? "none usable" : dane_strerror(rc)); #endif badcert: @@ -1948,7 +2056,107 @@ 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 GNUTLS_TLS1_3 +if (gnutls_protocol_get_version(state->session) < GNUTLS_TLS1_3) +#else +if (TRUE) +#endif + { + gnutls_datum_t c, s; + gstring * gc, * gs; + /* 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 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"); +#endif +} + + +#ifdef EXPERIMENTAL_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_NEW_SESSION_TICKET, GNUTLS_HOOK_POST, tls_server_ticket_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 */ @@ -1980,9 +2188,9 @@ int rc; exim_gnutls_state_st * state = NULL; /* Check for previous activation */ -if (tls_in.active >= 0) +if (tls_in.active.sock >= 0) { - tls_error(US"STARTTLS received after TLS started", "", NULL, errstr); + tls_error(US"STARTTLS received after TLS started", US "", NULL, errstr); smtp_printf("554 Already in TLS\r\n", FALSE); return FAIL; } @@ -1994,7 +2202,11 @@ 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, errstr)) != OK) return rc; + require_ciphers, &state, &tls_in, errstr)) != OK) return rc; + +#ifdef EXPERIMENTAL_TLS_RESUME +tls_server_resume_prehandshake(state); +#endif /* If this is a host for which certificate verification is mandatory or optional, set up appropriately. */ @@ -2049,7 +2261,10 @@ if (!state->tlsp->on_connect) } /* Now negotiate the TLS session. We put our own timer on it, since it seems -that the GnuTLS library doesn't. */ +that the GnuTLS library doesn't. +From 3.1.0 there is gnutls_handshake_set_timeout() - but it requires you +to set (and clear down afterwards) up a pull-timeout callback function that does +a select, so we're no better off unless avoiding signals becomes an issue. */ gnutls_transport_set_ptr2(state->session, (gnutls_transport_ptr_t)(long) fileno(smtp_in), @@ -2058,11 +2273,11 @@ state->fd_in = fileno(smtp_in); state->fd_out = fileno(smtp_out); sigalrm_seen = FALSE; -if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); +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); -alarm(0); +ALARM_CLR(0); if (rc != GNUTLS_E_SUCCESS) { @@ -2072,18 +2287,18 @@ if (rc != GNUTLS_E_SUCCESS) if (sigalrm_seen) { - tls_error(US"gnutls_handshake", "timed out", NULL, errstr); + tls_error(US"gnutls_handshake", US"timed out", NULL, errstr); gnutls_db_remove_session(state->session); } else { - tls_error(US"gnutls_handshake", gnutls_strerror(rc), NULL, errstr); + tls_error_gnu(US"gnutls_handshake", rc, NULL, errstr); (void) gnutls_alert_send_appropriate(state->session, rc); gnutls_deinit(state->session); gnutls_certificate_free_credentials(state->x509_cred); millisleep(500); shutdown(state->fd_out, SHUT_WR); - for (rc = 1024; fgetc(smtp_in) != EOF && rc > 0; ) rc--; /* drain skt */ + for (int i = 1024; fgetc(smtp_in) != EOF && i > 0; ) i--; /* drain skt */ (void)fclose(smtp_out); (void)fclose(smtp_in); smtp_out = smtp_in = NULL; @@ -2092,7 +2307,11 @@ if (rc != GNUTLS_E_SUCCESS) return FAIL; } -DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n"); +#ifdef EXPERIMENTAL_TLS_RESUME +tls_server_resume_posthandshake(state); +#endif + +DEBUG(D_tls) post_handshake_debug(state); /* Verify after the fact */ @@ -2108,10 +2327,6 @@ 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); @@ -2139,7 +2354,7 @@ 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) +if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK) { state->exp_tls_verify_cert_hostnames = #ifdef SUPPORT_I18N @@ -2167,24 +2382,23 @@ after verification is done.*/ static BOOL dane_tlsa_load(exim_gnutls_state_st * state, dns_answer * dnsa) { -dns_record * rr; dns_scan dnss; int i; const char ** dane_data; int * dane_data_len; -for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS), i = 1; - rr; +i = 1; +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)); -for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS), i = 0; - rr; +i = 0; +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) + ) if (rr->type == T_TLSA && rr->size > 3) { const uschar * p = rr->data; uint8_t usage = p[0], sel = p[1], type = p[2]; @@ -2208,7 +2422,7 @@ for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS), i = 0; } tls_out.tlsa_usage |= 1<size; } @@ -2225,6 +2439,142 @@ return TRUE; +#ifdef EXPERIMENTAL_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); + + 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 /* EXPERIMENTAL_TLS_RESUME */ + + /************************************************* * Start a TLS session in a client * *************************************************/ @@ -2232,51 +2582,51 @@ return TRUE; /* Called from the smtp transport after STARTTLS has been accepted. Arguments: - fd the fd of the connection - host connected host (for messages) - 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 - errstr error string pointer - -Returns: OK/DEFER/FAIL (because using common functions), - but for a client, DEFER and FAIL have the same meaning + 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 */ -int -tls_client_start(int fd, host_item *host, - address_item *addr ARG_UNUSED, - transport_instance * tb, -#ifdef SUPPORT_DANE - dns_answer * tlsa_dnsa, -#endif - 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 = - (smtp_transport_options_block *)tb->options_block; +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 = - verify_check_given_host(&ob->hosts_require_ocsp, host) == OK; + verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK; BOOL request_ocsp = require_ocsp ? TRUE - : verify_check_given_host(&ob->hosts_request_ocsp, host) == OK; + : 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 */ + +if (conn_args->dane && ob->dane_require_tls_ciphers) { /* 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 DEFER; + return FALSE; cipher_list = cipher_list && *cipher_list ? ob->dane_require_tls_ciphers : ob->tls_require_ciphers; } @@ -2285,10 +2635,10 @@ if (tlsa_dnsa && ob->dane_require_tls_ciphers) if (!cipher_list) cipher_list = ob->tls_require_ciphers; -if ((rc = tls_init(host, ob->tls_certificate, ob->tls_privatekey, +if (tls_init(host, ob->tls_certificate, ob->tls_privatekey, ob->tls_sni, ob->tls_verify_certificates, ob->tls_crl, - cipher_list, &state, errstr)) != OK) - return rc; + cipher_list, &state, tlsp, errstr) != OK) + return FALSE; { int dh_min_bits = ob->tls_dh_min_bits; @@ -2312,7 +2662,7 @@ 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"); @@ -2325,7 +2675,7 @@ else && !ob->tls_verify_hosts && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) ) - || verify_check_given_host(&ob->tls_verify_hosts, host) == OK + || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK ) { tls_client_setup_hostname_checks(host, state, ob); @@ -2334,7 +2684,7 @@ else state->verify_requirement = VERIFY_REQUIRED; gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); } -else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK) +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) @@ -2357,14 +2707,20 @@ if (request_ocsp) DEBUG(D_tls) debug_printf("TLS: will request OCSP stapling\n"); if ((rc = gnutls_ocsp_status_request_enable_client(state->session, NULL, 0, NULL)) != OK) - return tls_error(US"cert-status-req", - gnutls_strerror(rc), state->host, errstr); - tls_out.ocsp = OCSP_NOT_RESP; + { + tls_error_gnu(US"cert-status-req", rc, state->host, errstr); + return FALSE; + } + tlsp->ocsp = OCSP_NOT_RESP; } #endif +#ifdef EXPERIMENTAL_TLS_RESUME +tls_client_resume_prehandshake(state, tlsp, host, ob); +#endif + #ifndef DISABLE_EVENT -if (tb->event_action) +if (tb && tb->event_action) { state->event_action = tb->event_action; gnutls_session_set_ptr(state->session, state); @@ -2372,38 +2728,44 @@ if (tb->event_action) } #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. */ sigalrm_seen = FALSE; -alarm(ob->command_timeout); +ALARM(ob->command_timeout); do rc = gnutls_handshake(state->session); while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen); -alarm(0); +ALARM_CLR(0); if (rc != GNUTLS_E_SUCCESS) + { 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, errstr); + tls_error(US"gnutls_handshake", US"timed out", state->host, errstr); } else - return tls_error(US"gnutls_handshake", gnutls_strerror(rc), state->host, errstr); + tls_error_gnu(US"gnutls_handshake", rc, state->host, 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)) - return tls_error(US"certificate verification failed", *errstr, state->host, errstr); + { + tls_error(US"certificate verification failed", *errstr, state->host, errstr); + return FALSE; + } #ifndef DISABLE_OCSP -if (require_ocsp) +if (request_ocsp) { DEBUG(D_tls) { @@ -2420,29 +2782,34 @@ if (require_ocsp) gnutls_free(printed.data); } else - (void) tls_error(US"ocsp decode", gnutls_strerror(rc), state->host, errstr); + (void) tls_error_gnu(US"ocsp decode", rc, state->host, errstr); } if (gnutls_ocsp_status_request_is_checked(state->session, 0) == 0) { - tls_out.ocsp = OCSP_FAILED; - return tls_error(US"certificate status check failed", NULL, state->host, errstr); + tlsp->ocsp = OCSP_FAILED; + tls_error(US"certificate status check failed", NULL, state->host, errstr); + 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"); - tls_out.ocsp = OCSP_VFIED; } #endif -/* Figure out peer DN, and if authenticated, etc. */ - -if ((rc = peer_status(state, errstr)) != OK) - return rc; +#ifdef EXPERIMENTAL_TLS_RESUME +tls_client_resume_posthandshake(state, tlsp, host); +#endif /* Sets various Exim expansion variables; may need to adjust for ACL callouts */ extract_exim_vars_from_tls_state(state); -return OK; +cctx->tls_ctx = state; +return TRUE; } @@ -2457,42 +2824,38 @@ daemon, to shut down the TLS library, without actually doing a shutdown (which 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 + 2 if also response to be waited for Returns: nothing */ void -tls_close(BOOL is_server, int shutdown) +tls_close(void * ct_ctx, int shutdown) { -exim_gnutls_state_st *state = is_server ? &state_server : &state_client; +exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; -if (!state->tlsp || state->tlsp->active < 0) return; /* TLS was not active */ +if (!state->tlsp || state->tlsp->active.sock < 0) return; /* TLS was not active */ if (shutdown) { DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n", shutdown > 1 ? " (with response-wait)" : ""); - alarm(2); + ALARM(2); gnutls_bye(state->session, shutdown > 1 ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR); - alarm(0); + ALARM_CLR(0); } gnutls_deinit(state->session); gnutls_certificate_free_credentials(state->x509_cred); -state->tlsp->active = -1; +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)); - -if (!state_server.session && !state_client.session) - { - gnutls_global_deinit(); - exim_gnutls_base_init_done = FALSE; - } } @@ -2508,10 +2871,14 @@ 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)); -if (smtp_receive_timeout > 0) alarm(0); +if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout); + +do + inbytes = gnutls_record_recv(state->session, state->xfer_buffer, + MIN(ssl_xfer_buffer_size, lim)); +while (inbytes == GNUTLS_E_AGAIN); + +if (smtp_receive_timeout > 0) ALARM_CLR(0); if (had_command_timeout) /* set by signal handler */ smtp_command_timeout_exit(); /* does not return */ @@ -2549,7 +2916,8 @@ else if (inbytes == 0) gnutls_certificate_free_credentials(state->x509_cred); state->session = NULL; - state->tlsp->active = -1; + state->tlsp->active.sock = -1; + state->tlsp->active.tls_ctx = NULL; state->tlsp->bits = 0; state->tlsp->certificate_verified = FALSE; tls_channelbinding_b64 = NULL; @@ -2564,6 +2932,7 @@ else if (inbytes == 0) else if (inbytes < 0) { + 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; @@ -2586,7 +2955,7 @@ 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 */ @@ -2658,17 +3027,18 @@ return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm then the caller must feed DKIM. Arguments: + ct_ctx client context pointer, or NULL for the one global server context buff buffer of data len size of buffer Returns: the number of bytes read - -1 after a failed read + -1 after a failed read, including EOF */ int -tls_read(BOOL is_server, uschar *buff, size_t len) +tls_read(void * ct_ctx, uschar *buff, size_t len) { -exim_gnutls_state_st *state = is_server ? &state_server : &state_client; +exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; ssize_t inbytes; if (len > INT_MAX) @@ -2684,13 +3054,20 @@ DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, " SIZE_T_FMT ")\n", state->session, buff, len); -inbytes = gnutls_record_recv(state->session, buff, len); +do + inbytes = gnutls_record_recv(state->session, buff, len); +while (inbytes == GNUTLS_E_AGAIN); + if (inbytes > 0) return inbytes; if (inbytes == 0) { DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); } -else record_io_error(state, (int)inbytes, US"recv", NULL); +else + { + DEBUG(D_tls) debug_printf("%s: err from gnutls_record_recv\n", __FUNCTION__); + record_io_error(state, (int)inbytes, US"recv", NULL); + } return -1; } @@ -2704,7 +3081,7 @@ return -1; /* Arguments: - is_server channel specifier + ct_ctx client context pointer, or NULL for the one global server context buff buffer of data len number of bytes more more data expected soon @@ -2714,11 +3091,11 @@ Returns: the number of bytes after a successful write, */ int -tls_write(BOOL is_server, const uschar *buff, size_t len, BOOL more) +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 = is_server ? &state_server : &state_client; +exim_gnutls_state_st * state = ct_ctx ? ct_ctx : &state_server; #ifdef SUPPORT_CORK static BOOL corked = FALSE; @@ -2732,11 +3109,15 @@ while (left > 0) { DEBUG(D_tls) debug_printf("gnutls_record_send(SSL, %p, " SIZE_T_FMT ")\n", buff, left); - outbytes = gnutls_record_send(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); return -1; } @@ -2793,7 +3174,6 @@ vaguely_random_number(int max) { unsigned int r; int i, needed_len; -uschar *p; uschar smallbuf[sizeof(r)]; if (max <= 1) @@ -2801,7 +3181,8 @@ if (max <= 1) needed_len = sizeof(r); /* Don't take 8 times more entropy than needed if int is 8 octets and we were - * asked for a number less than 10. */ +asked for a number less than 10. */ + for (r = max, i = 0; r; ++i) r >>= 1; i = (i + 7) / 8; @@ -2815,11 +3196,8 @@ if (i < 0) return vaguely_random_number_fallback(max); } r = 0; -for (p = smallbuf; needed_len; --needed_len, ++p) - { - r *= 256; - r += *p; - } +for (uschar * p = smallbuf; needed_len; --needed_len, ++p) + r = r * 256 + *p; /* We don't particularly care about weighted results; if someone wants * smooth distribution and cares enough then they should submit a patch then. */ @@ -2922,6 +3300,7 @@ 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 */