X-Git-Url: https://vcs.fsf.org/?p=exim.git;a=blobdiff_plain;f=src%2Fsrc%2Ftls-gnu.c;h=e08381344dd51e3967d5e7bf90b9378e016710a6;hp=c9dc4d9be02359ad29a8484d27dd485aea72f15e;hb=b9c6f63cd56eaf62303792630a1fa5657499e7a6;hpb=9960d1e59f08254a951283981d4a32c73ca7d3ad diff --git a/src/src/tls-gnu.c b/src/src/tls-gnu.c index c9dc4d9be..e08381344 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 - 2015 */ +/* Copyright (c) University of Cambridge 1995 - 2018 */ /* See the file NOTICE for conditions of use and distribution. */ /* Copyright (c) Phil Pennock 2012 */ @@ -13,7 +13,7 @@ tls.c when USE_GNUTLS has been set. The code herein is a revamp of GnuTLS integration using the current APIs; the original tls-gnu.c was based on a patch which was contributed by Nikos -Mavroyanopoulos. The revamp is partially a rewrite, partially cut&paste as +Mavrogiannopoulos. The revamp is partially a rewrite, partially cut&paste as appropriate. APIs current as of GnuTLS 2.12.18; note that the GnuTLS manual is for GnuTLS 3, @@ -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 @@ -60,10 +61,43 @@ 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 + +#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 # include #endif +#ifdef SUPPORT_DANE +# include +#endif + +#include "tls-cipher-stdname.c" + /* GnuTLS 2 vs 3 @@ -79,7 +113,7 @@ Changes: /* Values for verify_requirement */ enum peer_verify_requirement - { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED }; + { VERIFY_NONE, VERIFY_OPTIONAL, VERIFY_REQUIRED, VERIFY_DANE }; /* 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 @@ -100,10 +134,11 @@ typedef struct exim_gnutls_state { int fd_in; int fd_out; BOOL peer_cert_verified; + 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; @@ -120,32 +155,64 @@ typedef struct exim_gnutls_state { uschar *exp_tls_verify_certificates; uschar *exp_tls_crl; uschar *exp_tls_require_ciphers; - uschar *exp_tls_ocsp_file; const uschar *exp_tls_verify_cert_hostnames; #ifndef DISABLE_EVENT uschar *event_action; #endif +#ifdef SUPPORT_DANE + char * const * dane_data; + const int * dane_data_len; +#endif tls_support *tlsp; /* set in tls_init() */ uschar *xfer_buffer; int xfer_buffer_lwm; int xfer_buffer_hwm; - int xfer_eof; - int xfer_error; + BOOL xfer_eof; /*XXX never gets set! */ + BOOL xfer_error; } exim_gnutls_state_st; static const exim_gnutls_state_st exim_gnutls_state_init = { - NULL, NULL, NULL, VERIFY_NONE, -1, -1, FALSE, FALSE, FALSE, - NULL, NULL, NULL, NULL, - NULL, NULL, NULL, NULL, NULL, NULL, - NULL, NULL, NULL, NULL, NULL, NULL, NULL, - NULL, + .session = NULL, + .x509_cred = NULL, + .priority_cache = NULL, + .verify_requirement = VERIFY_NONE, + .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 - NULL, + .event_action = NULL, #endif - NULL, - NULL, 0, 0, 0, 0, + .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 @@ -159,7 +226,7 @@ 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 @@ -171,7 +238,7 @@ static gnutls_dh_params_t dh_server_params = NULL; static const int ssl_session_timeout = 200; -static const char * const exim_default_gnutls_priority = "NORMAL"; +static const uschar * const exim_default_gnutls_priority = US"NORMAL"; /* Guard library core initialisation */ @@ -189,7 +256,10 @@ 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. */ +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 @@ -205,10 +275,8 @@ before, for now. */ # define EXIM_SERVER_DH_BITS_PRE2_12 1024 #endif -#define exim_gnutls_err_check(Label) do { \ - if (rc != GNUTLS_E_SUCCESS) { return tls_error((Label), gnutls_strerror(rc), host); } } while (0) - -#define expand_check_tlsvar(Varname) expand_check(state->Varname, US #Varname, &state->exp_##Varname) +#define expand_check_tlsvar(Varname, errstr) \ + expand_check(state->Varname, US #Varname, &state->exp_##Varname, errstr) #if GNUTLS_VERSION_NUMBER >= 0x020c00 # define HAVE_GNUTLS_SESSION_CHANNEL_BINDING @@ -264,32 +332,34 @@ Argument: usually obtained from gnutls_strerror() host NULL if setting up a server; the connected host if setting up a client + errstr pointer to returned error string 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 (host) - { - 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; - } -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; - } +if (errstr) + *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); +} /************************************************* @@ -302,7 +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 */ @@ -310,15 +380,27 @@ 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); -tls_error(when, msg, state->host); +(void) tls_error(when, msg, state->host, &errstr); + +if (state->host) + log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection %s", + state->host->name, state->host->address, errstr); +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", conn_info, errstr); + } } @@ -389,7 +471,8 @@ gnutls_datum_t channel; #endif tls_support * tlsp = state->tlsp; -tlsp->active = state->fd_out; +tlsp->active.sock = state->fd_out; +tlsp->active.tls_ctx = state; cipher = gnutls_cipher_get(state->session); /* returns size in "bytes" */ @@ -400,6 +483,9 @@ tlsp->cipher = state->ciphersuite; DEBUG(D_tls) debug_printf("cipher: %s\n", state->ciphersuite); tlsp->certificate_verified = state->peer_cert_verified; +#ifdef SUPPORT_DANE +tlsp->dane_verified = state->peer_dane_verified; +#endif /* note that tls_channelbinding_b64 is not saved to the spool file, since it's only available for use for authenticators while this TLS session is running. */ @@ -408,16 +494,16 @@ 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() */ @@ -454,7 +540,7 @@ Returns: OK/DEFER/FAIL */ static int -init_server_dh(void) +init_server_dh(uschar ** errstr) { int fd, rc; unsigned int dh_bits; @@ -464,18 +550,17 @@ 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(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; -if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam)) +if (!expand_check(tls_dhparam, US"tls_dhparam", &exp_tls_dhparam, errstr)) return DEFER; if (!exp_tls_dhparam) @@ -493,21 +578,17 @@ else if (Ustrcmp(exp_tls_dhparam, "none") == 0) } else if (exp_tls_dhparam[0] != '/') { - m.data = US std_dh_prime_named(exp_tls_dhparam); - if (m.data == NULL) - return tls_error(US"No standard prime named", CS exp_tls_dhparam, NULL); + if (!(m.data = US std_dh_prime_named(exp_tls_dhparam))) + 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(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; } @@ -515,9 +596,9 @@ 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) - return tls_error(US"gnutls_sec_param_to_pk_bits() failed", NULL, NULL); + +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", dh_bits); @@ -541,15 +622,14 @@ if (use_file_in_spool) { if (!string_format(filename_buf, sizeof(filename_buf), "%s/gnutls-params-%d", spool_directory, dh_bits)) - return tls_error(US"overlong filename", NULL, NULL); + return tls_error(US"overlong filename", NULL, NULL, errstr); filename = filename_buf; } /* Open the cache file for reading and if successful, read it and set up the parameters. */ -fd = Uopen(filename, O_RDONLY, 0); -if (fd >= 0) +if ((fd = Uopen(filename, O_RDONLY, 0)) >= 0) { struct stat statbuf; FILE *fp; @@ -559,42 +639,40 @@ if (fd >= 0) { saved_errno = errno; (void)close(fd); - return tls_error(US"TLS cache stat failed", strerror(saved_errno), NULL); + return tls_error_sys(US"TLS cache stat failed", saved_errno, NULL, errstr); } if (!S_ISREG(statbuf.st_mode)) { (void)close(fd); - return tls_error(US"TLS cache not a file", NULL, NULL); + return tls_error(US"TLS cache not a file", NULL, NULL, errstr); } - fp = fdopen(fd, "rb"); - if (!fp) + if (!(fp = fdopen(fd, "rb"))) { saved_errno = errno; (void)close(fd); - return tls_error(US"fdopen(TLS cache stat fd) failed", - strerror(saved_errno), NULL); + return tls_error_sys(US"fdopen(TLS cache stat fd) failed", + saved_errno, NULL, errstr); } 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); + return tls_error_sys(US"malloc failed", errno, NULL, errstr); } - sz = fread(m.data, m.size, 1, fp); - if (!sz) + 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); + 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(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); } @@ -609,7 +687,7 @@ else if (errno == ENOENT) } else return tls_error(string_open_failed(errno, "\"%s\" for reading", filename), - NULL, NULL); + NULL, NULL, errstr); /* If ret < 0, either the cache file does not exist, or the data it contains is not useful. One particular case of this is when upgrading from an older @@ -624,13 +702,12 @@ if (rc < 0) if ((PATH_MAX - Ustrlen(filename)) < 10) return tls_error(US"Filename too long to generate replacement", - CS filename, NULL); + filename, NULL, errstr); - temp_fn = string_copy(US "%s.XXXXXXX"); - fd = mkstemp(CS temp_fn); /* modifies temp_fn */ - if (fd < 0) - return tls_error(US"Unable to open temp file", strerror(errno), NULL); - (void)fchown(fd, exim_uid, exim_gid); /* Probably not necessary */ + temp_fn = string_copy(US"%s.XXXXXXX"); + if ((fd = mkstemp(CS temp_fn)) < 0) /* modifies temp_fn */ + 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. @@ -651,8 +728,8 @@ 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(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 @@ -660,45 +737,41 @@ 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(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; - m.data = malloc(m.size); - if (m.data == NULL) - return tls_error(US"memory allocation failed", strerror(errno), NULL); + if (!(m.data = malloc(m.size))) + return tls_error_sys(US"memory allocation failed", errno, NULL, errstr); + /* this will return a size 1 less than the allocation size above */ - rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, - m.data, &sz); - if (rc != GNUTLS_E_SUCCESS) + if ((rc = gnutls_dh_params_export_pkcs3(dh_server_params, GNUTLS_X509_FMT_PEM, + m.data, &sz))) { free(m.data); - exim_gnutls_err_check(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 */ - sz = write_to_fd_buf(fd, m.data, (size_t) m.size); - if (sz != m.size) + 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); + return tls_error_sys(US"TLS cache write D-H params failed", + errno, NULL, errstr); } free(m.data); - sz = write_to_fd_buf(fd, US"\n", 1); - if (sz != 1) - return tls_error(US"TLS cache write D-H params final newline failed", - strerror(errno), NULL); + if ((sz = write_to_fd_buf(fd, US"\n", 1)) != 1) + return tls_error_sys(US"TLS cache write D-H params final newline failed", + errno, NULL, errstr); - rc = close(fd); - if (rc) - return tls_error(US"TLS cache write close() failed", - strerror(errno), NULL); + if ((rc = close(fd))) + 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); + 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); } @@ -713,7 +786,7 @@ return OK; /* Create and install a selfsigned certificate, for use in server mode */ static int -tls_install_selfsign(exim_gnutls_state_st * state) +tls_install_selfsign(exim_gnutls_state_st * state, uschar ** errstr) { gnutls_x509_crt_t cert = NULL; time_t now; @@ -730,15 +803,18 @@ 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))) @@ -771,13 +847,34 @@ out: return rc; err: - rc = tls_error(where, gnutls_strerror(rc), NULL); + rc = tls_error_gnu(where, rc, NULL, errstr); goto out; } +/* Add certificate and key, from files. + +Return: + Zero or negative: good. Negate value for certificate index if < 0. + Greater than zero: FAIL or DEFER code. +*/ + +static int +tls_add_certfile(exim_gnutls_state_st * state, const host_item * host, + uschar * certfile, uschar * keyfile, uschar ** errstr) +{ +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_gnu( + string_sprintf("cert/key setup: cert=%s key=%s", certfile, keyfile), + rc, host, errstr); +return -rc; +} + + /************************************************* * Variables re-expanded post-SNI * *************************************************/ @@ -792,12 +889,13 @@ which we are responsible for setting on the first pass through. Arguments: state exim_gnutls_state_st * + errstr error string pointer Returns: OK/DEFER/FAIL */ static int -tls_expand_session_files(exim_gnutls_state_st *state) +tls_expand_session_files(exim_gnutls_state_st * state, uschar ** errstr) { struct stat statbuf; int rc; @@ -812,11 +910,11 @@ int cert_count; if (!host) /* server */ if (!state->received_sni) { - if (state->tls_certificate && - (Ustrstr(state->tls_certificate, US"tls_sni") || - Ustrstr(state->tls_certificate, US"tls_in_sni") || - Ustrstr(state->tls_certificate, US"tls_out_sni") - )) + if ( state->tls_certificate + && ( Ustrstr(state->tls_certificate, US"tls_sni") + || Ustrstr(state->tls_certificate, US"tls_in_sni") + || Ustrstr(state->tls_certificate, US"tls_out_sni") + ) ) { DEBUG(D_tls) debug_printf("We will re-expand TLS session files if we receive SNI.\n"); state->trigger_sni_changes = TRUE; @@ -831,8 +929,13 @@ if (!host) /* server */ saved_tls_crl = state->exp_tls_crl; } -rc = gnutls_certificate_allocate_credentials(&state->x509_cred); -exim_gnutls_err_check(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); +#endif /* remember: expand_check_tlsvar() is expand_check() but fiddling with state members, assuming consistent naming; and expand_check() returns @@ -841,7 +944,7 @@ false if expansion failed, unless expansion was forced to fail. */ /* check if we at least have a certificate, before doing expensive D-H generation. */ -if (!expand_check_tlsvar(tls_certificate)) +if (!expand_check_tlsvar(tls_certificate, errstr)) return DEFER; /* certificate is mandatory in server, optional in client */ @@ -850,11 +953,11 @@ if ( !state->exp_tls_certificate || !*state->exp_tls_certificate ) if (!host) - return tls_install_selfsign(state); + return tls_install_selfsign(state, errstr); else DEBUG(D_tls) debug_printf("TLS: no client certificate specified; okay\n"); -if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey)) +if (state->tls_privatekey && !expand_check_tlsvar(tls_privatekey, errstr)) return DEFER; /* tls_privatekey is optional, defaulting to same file as certificate */ @@ -883,44 +986,81 @@ 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, - GNUTLS_X509_FMT_PEM); - exim_gnutls_err_check( - string_sprintf("cert/key setup: cert=%s key=%s", - state->exp_tls_certificate, state->exp_tls_privatekey)); - DEBUG(D_tls) debug_printf("TLS: cert/key registered\n"); - } /* tls_certificate */ + if (!host) /* server */ + { + const uschar * clist = state->exp_tls_certificate; + const uschar * klist = state->exp_tls_privatekey; + const uschar * olist; + int csep = 0, ksep = 0, osep = 0, cnt = 0; + uschar * cfile, * kfile, * ofile; +#ifndef DISABLE_OCSP + if (!expand_check(tls_ocsp_file, US"tls_ocsp_file", &ofile, errstr)) + return DEFER; + olist = ofile; +#endif -/* Set the OCSP stapling server info */ + while (cfile = string_nextinlist(&clist, &csep, NULL, 0)) + + if (!(kfile = string_nextinlist(&klist, &ksep, NULL, 0))) + return tls_error(US"cert/key setup: out of keys", NULL, host, errstr); + else if (0 < (rc = tls_add_certfile(state, host, cfile, kfile, errstr))) + return rc; + else + { + int gnutls_cert_index = -rc; + DEBUG(D_tls) debug_printf("TLS: cert/key %s registered\n", cfile); + + /* Set the OCSP stapling server info */ #ifndef DISABLE_OCSP -if ( !host /* server */ - && tls_ocsp_file - ) - { - if (gnutls_buggy_ocsp) - { - DEBUG(D_tls) debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); + if (tls_ocsp_file) + if (gnutls_buggy_ocsp) + { + DEBUG(D_tls) + debug_printf("GnuTLS library is buggy for OCSP; avoiding\n"); + } + else if ((ofile = string_nextinlist(&olist, &osep, NULL, 0))) + { + /* 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. */ + +# ifdef SUPPORT_SRV_OCSP_STACK + if ((rc = gnutls_certificate_set_ocsp_status_request_function2( + state->x509_cred, gnutls_cert_index, + server_ocsp_stapling_cb, ofile))) + return tls_error_gnu( + US"gnutls_certificate_set_ocsp_status_request_function2", + rc, host, errstr); +# else + if (cnt++ > 0) + { + DEBUG(D_tls) + debug_printf("oops; multiple OCSP files not supported\n"); + break; + } + gnutls_certificate_set_ocsp_status_request_function( + state->x509_cred, server_ocsp_stapling_cb, ofile); +# endif + + DEBUG(D_tls) debug_printf("OCSP response file = %s\n", ofile); + } + else + DEBUG(D_tls) debug_printf("ran out of OCSP response files in list\n"); +#endif + } } 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. */ - - gnutls_certificate_set_ocsp_status_request_function(state->x509_cred, - server_ocsp_stapling_cb, state->exp_tls_ocsp_file); - - DEBUG(D_tls) debug_printf("OCSP response file = %s\n", state->exp_tls_ocsp_file); + if (0 < (rc = tls_add_certfile(state, host, + state->exp_tls_certificate, state->exp_tls_privatekey, errstr))) + return rc; + DEBUG(D_tls) debug_printf("TLS: cert/key registered\n"); } - } -#endif + + } /* tls_certificate */ /* Set the trusted CAs file if one is provided, and then add the CRL if one is @@ -931,14 +1071,14 @@ behaviour. */ if (state->tls_verify_certificates && *state->tls_verify_certificates) { - if (!expand_check_tlsvar(tls_verify_certificates)) + if (!expand_check_tlsvar(tls_verify_certificates, errstr)) return DEFER; #ifndef SUPPORT_SYSDEFAULT_CABUNDLE if (Ustrcmp(state->exp_tls_verify_certificates, "system") == 0) state->exp_tls_verify_certificates = NULL; #endif if (state->tls_crl && *state->tls_crl) - if (!expand_check_tlsvar(tls_crl)) + if (!expand_check_tlsvar(tls_crl, errstr)) return DEFER; if (!(state->exp_tls_verify_certificates && @@ -1013,23 +1153,19 @@ else } if (cert_count < 0) - { - rc = cert_count; - exim_gnutls_err_check(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(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); } @@ -1051,12 +1187,13 @@ out to this. Arguments: state exim_gnutls_state_st * + errstr error string pointer Returns: OK/DEFER/FAIL */ static int -tls_set_remaining_x509(exim_gnutls_state_st *state) +tls_set_remaining_x509(exim_gnutls_state_st *state, uschar ** errstr) { int rc; const host_item *host = state->host; /* macro should be reconsidered? */ @@ -1068,17 +1205,15 @@ client-side params. */ if (!state->host) { if (!dh_server_params) - { - rc = init_server_dh(); - 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(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; } @@ -1131,6 +1266,7 @@ Arguments: crl CRL file require_ciphers tls_require_ciphers setting caller_state returned state-info structure + errstr error string pointer Returns: OK/DEFER/FAIL */ @@ -1144,14 +1280,15 @@ tls_init( const uschar *cas, const uschar *crl, const uschar *require_ciphers, - exim_gnutls_state_st **caller_state) + 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) { @@ -1164,20 +1301,18 @@ 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(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(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 @@ -1192,9 +1327,15 @@ 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); } @@ -1202,11 +1343,12 @@ 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(US"gnutls_init"); +if (rc) + return tls_error_gnu(US"gnutls_init", rc, host, errstr); state->host = host; @@ -1222,33 +1364,31 @@ that's tls_certificate, tls_privatekey, tls_verify_certificates, tls_crl */ DEBUG(D_tls) debug_printf("Expanding various TLS configuration options for session credentials.\n"); -rc = tls_expand_session_files(state); -if (rc != OK) return rc; +if ((rc = tls_expand_session_files(state, errstr)) != OK) return rc; /* These are all other parts of the x509_cred handling, since SNI in GnuTLS requires a new structure afterwards. */ -rc = tls_set_remaining_x509(state); -if (rc != OK) return rc; +if ((rc = tls_set_remaining_x509(state, errstr)) != OK) return rc; /* set SNI in client, only */ if (host) { - if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni)) + if (!expand_check(sni, US"tls_out_sni", &state->tlsp->sni, errstr)) return DEFER; if (state->tlsp->sni && *state->tlsp->sni) { DEBUG(D_tls) debug_printf("Setting TLS client SNI to \"%s\"\n", state->tlsp->sni); sz = Ustrlen(state->tlsp->sni); - rc = gnutls_server_name_set(state->session, - GNUTLS_NAME_DNS, state->tlsp->sni, sz); - exim_gnutls_err_check(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) DEBUG(D_tls) debug_printf("*** PROBABLY A BUG *** " \ - "have an SNI set for a client [%s]\n", state->tls_sni); + "have an SNI set for a server [%s]\n", state->tls_sni); /* This is the priority string support, http://www.gnutls.org/manual/html_node/Priority-Strings.html @@ -1256,39 +1396,32 @@ 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)) + 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(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(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); gnutls_db_set_cache_expiration(state->session, ssl_session_timeout); @@ -1314,6 +1447,25 @@ 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. @@ -1334,14 +1486,14 @@ don't apply. Arguments: state exim_gnutls_state_st * + errstr pointer to error string Returns: OK/DEFER/FAIL */ static int -peer_status(exim_gnutls_state_st *state) +peer_status(exim_gnutls_state_st *state, uschar ** errstr) { -uschar cipherbuf[256]; const gnutls_datum_t *cert_list; int old_pool, rc; unsigned int cert_list_size = 0; @@ -1351,7 +1503,7 @@ 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) @@ -1364,48 +1516,86 @@ state->peerdn = NULL; 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 = '-'; +kx = +#ifdef GNUTLS_TLS1_3 + protocol >= GNUTLS_TLS1_3 ? 0 : +#endif + gnutls_kx_get(state->session); + old_pool = store_pool; -store_pool = POOL_PERM; -state->ciphersuite = string_copy(cipherbuf); + { + store_pool = POOL_PERM; + +#ifdef SUPPORT_GNUTLS_SESS_DESC + { + gstring * g = NULL; + uschar * s = US gnutls_session_get_desc(state->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); */ + + state->tlsp->cipher = state->ciphersuite; + state->tlsp->bits = gnutls_cipher_get_key_size(cipher) * 8; + + state->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); -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); + 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(state->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) return tls_error(US"certificate verification not possible, unhandled type", - ctn, state->host); + ctn, state->host, errstr); return OK; } @@ -1416,7 +1606,7 @@ 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); \ + return tls_error_gnu((Label), rc, state->host, errstr); \ return OK; \ } \ } while (0) @@ -1456,8 +1646,8 @@ gnutls_certificate_set_verify_function() to fail the handshake if we dislike the peer information, but that's too new for some OSes. Arguments: - state exim_gnutls_state_st * - error where to put an error message + state exim_gnutls_state_st * + errstr where to put an error message Returns: FALSE if the session should be rejected @@ -1465,78 +1655,225 @@ Returns: */ static BOOL -verify_certificate(exim_gnutls_state_st *state, const char **error) +verify_certificate(exim_gnutls_state_st * state, uschar ** errstr) { int rc; -unsigned int verify; +uint verify; -*error = NULL; +if (state->verify_requirement == VERIFY_NONE) + return TRUE; -if ((rc = peer_status(state)) != OK) +DEBUG(D_tls) debug_printf("TLS: checking peer certificate\n"); +*errstr = NULL; + +if ((rc = peer_status(state, errstr)) != OK || !state->peerdn) { verify = GNUTLS_CERT_INVALID; - *error = "certificate not supplied"; + *errstr = US"certificate not supplied"; } else + + { +#ifdef SUPPORT_DANE + if (state->verify_requirement == VERIFY_DANE && state->host) + { + /* Using dane_verify_session_crt() would be easy, as it does it all for us + including talking to a DNS resolver. But we want to do that bit ourselves + as the testsuite intercepts and fakes its own DNS environment. */ + + dane_state_t s; + dane_query_t r; + 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 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; + } + } + } + + if (rc) goto tlsa_prob; + } + else +# endif + { + 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) /* verification failed */ + { + gnutls_datum_t str; + (void) dane_verification_status_print(verify, &str, 0); + *errstr = US str.data; /* don't bother to free */ + goto badcert; + } + +# ifdef GNUTLS_BROKEN_DANE_VALIDATION + /* If a TA-mode TLSA record was used for verification we must additionally + verify the cert name (but not the CA chain). For EE-mode, skip it. */ + + if (usage & (1 << DANESSL_USAGE_DANE_EE)) +# endif + { + 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 /*SUPPORT_DANE*/ + rc = gnutls_certificate_verify_peers2(state->session, &verify); + } -/* Handle the result of verification. INVALID seems to be set as well -as REVOKED, but leave the test for both. */ +/* Handle the result of verification. INVALID is set if any others are. */ -if (rc < 0 || - verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED) - ) +if (rc < 0 || verify & (GNUTLS_CERT_INVALID|GNUTLS_CERT_REVOKED)) { state->peer_cert_verified = FALSE; - if (!*error) - *error = verify & GNUTLS_CERT_REVOKED - ? "certificate revoked" : "certificate invalid"; + 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", - *error, state->peerdn ? state->peerdn : US""); + *errstr, state->peerdn ? state->peerdn : US""); if (state->verify_requirement >= VERIFY_REQUIRED) - { - gnutls_alert_send(state->session, - GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); - return FALSE; - } + goto badcert; DEBUG(D_tls) debug_printf("TLS verify failure overridden (host in tls_try_verify_hosts)\n"); } 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) - { - gnutls_alert_send(state->session, - GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); - return FALSE; - } - 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""); } -state->tlsp->peerdn = state->peerdn; +goodcert: + state->tlsp->peerdn = state->peerdn; + return TRUE; -return TRUE; +#ifdef SUPPORT_DANE +tlsa_prob: + *errstr = string_sprintf("TLSA record problem: %s", + rc == DANE_E_REQUESTED_DATA_NOT_AVAILABLE ? "none usable" : dane_strerror(rc)); +#endif + +badcert: + gnutls_alert_send(state->session, GNUTLS_AL_FATAL, GNUTLS_A_BAD_CERTIFICATE); + return FALSE; } @@ -1589,6 +1926,7 @@ size_t data_len = MAX_HOST_LEN; exim_gnutls_state_st *state = &state_server; unsigned int sni_type; int rc, old_pool; +uschar * dummy_errstr; rc = gnutls_server_name_get(session, sni_name, &data_len, &sni_type, 0); if (rc != GNUTLS_E_SUCCESS) @@ -1599,7 +1937,7 @@ if (rc != GNUTLS_E_SUCCESS) else debug_printf("TLS failure: gnutls_server_name_get(): %s [%d]\n", gnutls_strerror(rc), rc); - }; + } return 0; } @@ -1624,15 +1962,14 @@ DEBUG(D_tls) debug_printf("Received TLS SNI \"%s\"%s\n", sni_name, if (!state->trigger_sni_changes) return 0; -rc = tls_expand_session_files(state); -if (rc != OK) +if ((rc = tls_expand_session_files(state, &dummy_errstr)) != OK) { /* If the setup of certs/etc failed before handshake, TLS would not have been offered. The best we can do now is abort. */ return GNUTLS_E_APPLICATION_ERROR_MIN; } -rc = tls_set_remaining_x509(state); +rc = tls_set_remaining_x509(state, &dummy_errstr); if (rc != OK) return GNUTLS_E_APPLICATION_ERROR_MIN; return 0; @@ -1647,11 +1984,12 @@ server_ocsp_stapling_cb(gnutls_session_t session, void * ptr, gnutls_datum_t * ocsp_response) { int ret; +DEBUG(D_tls) debug_printf("OCSP stapling callback: %s\n", US ptr); if ((ret = gnutls_load_file(ptr, ocsp_response)) < 0) { DEBUG(D_tls) debug_printf("Failed to load ocsp stapling file %s\n", - (char *)ptr); + CS ptr); tls_in.ocsp = OCSP_NOT_RESP; return GNUTLS_E_NO_CERTIFICATE_STATUS; } @@ -1683,12 +2021,10 @@ 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) +if ((cert_list = gnutls_certificate_get_peers(session, &cert_list_size))) while (cert_list_size--) { - rc = import_cert(&cert_list[cert_list_size], &crt); - if (rc != GNUTLS_E_SUCCESS) + if ((rc = import_cert(&cert_list[cert_list_size], &crt)) != GNUTLS_E_SUCCESS) { DEBUG(D_tls) debug_printf("TLS: peer cert problem: depth %d: %s\n", cert_list_size, gnutls_strerror(rc)); @@ -1713,6 +2049,46 @@ 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) +{ +debug_printf("gnutls_handshake was successful\n"); +#ifdef SUPPORT_GNUTLS_SESS_DESC +debug_printf("%s\n", gnutls_session_get_desc(state->session)); +#endif +#ifdef SUPPORT_GNUTLS_KEYLOG +if (gnutls_protocol_get_version(state->session) < GNUTLS_TLS1_3) + { + 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 +} /* ------------------------------------------------------------------------ */ /* Exported functions */ @@ -1730,25 +2106,25 @@ a TLS session. Arguments: require_ciphers list of allowed ciphers or NULL + errstr pointer to error string Returns: OK on success DEFER for errors before the start of the negotiation - FAIL for errors during the negotation; the server can't + FAIL for errors during the negotiation; the server can't continue running. */ int -tls_server_start(const uschar *require_ciphers) +tls_server_start(const uschar * require_ciphers, uschar ** errstr) { int rc; -const char *error; -exim_gnutls_state_st *state = NULL; +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); - smtp_printf("554 Already in TLS\r\n"); + tls_error(US"STARTTLS received after TLS started", US "", NULL, errstr); + smtp_printf("554 Already in TLS\r\n", FALSE); return FAIL; } @@ -1757,10 +2133,9 @@ and sent an SMTP response. */ DEBUG(D_tls) debug_printf("initialising GnuTLS as a server\n"); -rc = tls_init(NULL, tls_certificate, tls_privatekey, +if ((rc = tls_init(NULL, tls_certificate, tls_privatekey, NULL, tls_verify_certificates, tls_crl, - require_ciphers, &state); -if (rc != OK) return rc; + require_ciphers, &state, &tls_in, errstr)) != OK) return rc; /* If this is a host for which certificate verification is mandatory or optional, set up appropriately. */ @@ -1810,12 +2185,15 @@ mode, the fflush() happens when smtp_getc() is called. */ if (!state->tlsp->on_connect) { - smtp_printf("220 TLS go ahead\r\n"); + smtp_printf("220 TLS go ahead\r\n", FALSE); fflush(smtp_out); } /* 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), @@ -1824,50 +2202,59 @@ 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) { - 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", US"timed out", NULL, errstr); + gnutls_db_remove_session(state->session); + } + else + { + 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 (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; } return FAIL; } -DEBUG(D_tls) debug_printf("gnutls_handshake was successful\n"); +DEBUG(D_tls) post_handshake_debug(state); /* Verify after the fact */ -if ( state->verify_requirement != VERIFY_NONE - && !verify_certificate(state, &error)) +if (!verify_certificate(state, errstr)) { if (state->verify_requirement != VERIFY_OPTIONAL) { - tls_error(US"certificate verification failed", error, NULL); + (void) tls_error(US"certificate verification failed", *errstr, NULL, errstr); return FAIL; } DEBUG(D_tls) debug_printf("TLS: continuing on only because verification was optional, after: %s\n", - error); + *errstr); } /* Figure out peer DN, and if authenticated, etc. */ -rc = peer_status(state); -if (rc != OK) return rc; +if ((rc = peer_status(state, NULL)) != OK) return rc; /* Sets various Exim expansion variables; always safe within server */ @@ -1879,6 +2266,7 @@ and initialize appropriately. */ state->xfer_buffer = store_malloc(ssl_xfer_buffer_size); receive_getc = tls_getc; +receive_getbuf = tls_getbuf; receive_get_cache = tls_get_cache; receive_ungetc = tls_ungetc; receive_feof = tls_feof; @@ -1895,7 +2283,7 @@ 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 @@ -1910,6 +2298,76 @@ if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK) } + + +#ifdef SUPPORT_DANE +/* Given our list of RRs from the TLSA lookup, build a lookup block in +GnuTLS-DANE's preferred format. Hang it on the state str for later +use in DANE verification. + +We point at the dnsa data not copy it, so it must remain valid until +after verification is done.*/ + +static BOOL +dane_tlsa_load(exim_gnutls_state_st * state, dns_answer * dnsa) +{ +dns_scan dnss; +int i; +const char ** dane_data; +int * dane_data_len; + +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)); + +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 && rr->size > 3) + { + const uschar * p = rr->data; + uint8_t usage = p[0], sel = p[1], type = p[2]; + + DEBUG(D_tls) + debug_printf("TLSA: %d %d %d size %d\n", usage, sel, type, rr->size); + + 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 */ + break; + case 1: if (rr->size != 3 + 256/8) continue; /* sha2-256 */ + break; + case 2: if (rr->size != 3 + 512/8) continue; /* sha2-512 */ + break; + default: continue; + } + + tls_out.tlsa_usage |= 1<size; + } + +if (!i) return FALSE; + +dane_data[i] = NULL; +dane_data_len[i] = 0; + +state->dane_data = (char * const *)dane_data; +state->dane_data_len = dane_data_len; +return TRUE; +} +#endif + + + /************************************************* * Start a TLS session in a client * *************************************************/ @@ -1917,42 +2375,63 @@ if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK) /* 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) - -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 EXPERIMENTAL_DANE - , dns_answer * unused_tlsa_dnsa -#endif - ) +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; -const char *error; -exim_gnutls_state_st *state = NULL; +exim_gnutls_state_st * state = 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", cctx->sock); + +#ifdef SUPPORT_DANE +/* 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 FALSE; + cipher_list = cipher_list && *cipher_list + ? ob->dane_require_tls_ciphers : ob->tls_require_ciphers; + } #endif -DEBUG(D_tls) debug_printf("initialising GnuTLS as a client on fd %d\n", fd); +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, - ob->tls_require_ciphers, &state)) != OK) - return rc; + cipher_list, &state, tlsp, errstr) != OK) + return FALSE; { int dh_min_bits = ob->tls_dh_min_bits; @@ -1975,12 +2454,22 @@ if ((rc = tls_init(host, ob->tls_certificate, ob->tls_privatekey, 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 || !*ob->tls_try_verify_hosts) - ) - || verify_check_given_host(&ob->tls_verify_hosts, host) == OK - ) +#ifdef SUPPORT_DANE +if (conn_args->dane && dane_tlsa_load(state, &conn_args->tlsa_dnsa)) + { + DEBUG(D_tls) + debug_printf("TLS: server certificate DANE required.\n"); + state->verify_requirement = VERIFY_DANE; + gnutls_certificate_server_set_request(state->session, GNUTLS_CERT_REQUIRE); + } +else +#endif + if ( ( state->exp_tls_verify_certificates + && !ob->tls_verify_hosts + && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) + ) + || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK + ) { tls_client_setup_hostname_checks(host, state, ob); DEBUG(D_tls) @@ -1988,7 +2477,7 @@ if ( ( state->exp_tls_verify_certificates 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) @@ -2011,14 +2500,16 @@ 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); - 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 #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); @@ -2026,33 +2517,41 @@ 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); +while (rc == GNUTLS_E_AGAIN || rc == GNUTLS_E_INTERRUPTED && !sigalrm_seen); +ALARM_CLR(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); + tls_error(US"gnutls_handshake", US"timed out", state->host, errstr); + } + else + 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 (state->verify_requirement != VERIFY_NONE && - !verify_certificate(state, &error)) - return tls_error(US"certificate verification failed", error, state->host); +if (!verify_certificate(state, errstr)) + { + tls_error(US"certificate verification failed", *errstr, state->host, errstr); + return FALSE; + } #ifndef DISABLE_OCSP if (require_ocsp) @@ -2072,29 +2571,31 @@ if (require_ocsp) gnutls_free(printed.data); } else - (void) tls_error(US"ocsp decode", gnutls_strerror(rc), state->host); + (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); + tlsp->ocsp = OCSP_FAILED; + tls_error(US"certificate status check failed", NULL, state->host, errstr); + return FALSE; } DEBUG(D_tls) debug_printf("Passed OCSP checking\n"); - tls_out.ocsp = OCSP_VFIED; + tlsp->ocsp = OCSP_VFIED; } #endif /* Figure out peer DN, and if authenticated, etc. */ -if ((rc = peer_status(state)) != OK) - return rc; +if (peer_status(state, errstr) != OK) + return FALSE; /* 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; } @@ -2108,38 +2609,127 @@ 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: + 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 + Returns: nothing */ void -tls_close(BOOL is_server, BOOL 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\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_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)); +} + + + + +static BOOL +tls_refill(unsigned lim) +{ +exim_gnutls_state_st * state = &state_server; +ssize_t inbytes; + +DEBUG(D_tls) debug_printf("Calling gnutls_record_recv(%p, %p, %u)\n", + state->session, state->xfer_buffer, ssl_xfer_buffer_size); + +sigalrm_seen = FALSE; +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 ((state_server.session == NULL) && (state_client.session == NULL)) +if (smtp_receive_timeout > 0) ALARM_CLR(0); + +if (had_command_timeout) /* set by signal handler */ + smtp_command_timeout_exit(); /* does not return */ +if (had_command_sigterm) + smtp_command_sigterm_exit(); +if (had_data_timeout) + smtp_data_timeout_exit(); +if (had_data_sigint) + smtp_data_sigint_exit(); + +/* Timeouts do not get this far. 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 (sigalrm_seen) { - gnutls_global_deinit(); - exim_gnutls_base_init_done = FALSE; + DEBUG(D_tls) debug_printf("Got tls read timeout\n"); + state->xfer_error = TRUE; + return FALSE; } -} +else if (inbytes == 0) + { + DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); + receive_getc = smtp_getc; + receive_getbuf = smtp_getbuf; + receive_get_cache = smtp_get_cache; + receive_ungetc = smtp_ungetc; + receive_feof = smtp_feof; + receive_ferror = smtp_ferror; + receive_smtp_buffered = smtp_buffered; + + gnutls_deinit(state->session); + gnutls_certificate_free_credentials(state->x509_cred); + + state->session = NULL; + state->tlsp->active.sock = -1; + state->tlsp->active.tls_ctx = NULL; + state->tlsp->bits = 0; + state->tlsp->certificate_verified = FALSE; + tls_channelbinding_b64 = NULL; + state->tlsp->cipher = NULL; + state->tlsp->peercert = NULL; + state->tlsp->peerdn = NULL; + return FALSE; + } +/* Handle genuine errors */ + +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; + } +#ifndef DISABLE_DKIM +dkim_exim_verify_feed(state->xfer_buffer, inbytes); +#endif +state->xfer_buffer_hwm = (int) inbytes; +state->xfer_buffer_lwm = 0; +return TRUE; +} /************************************************* * TLS version of getc * @@ -2151,74 +2741,48 @@ Only used by the server-side TLS. This feeds DKIM and should be used for all message-body reads. -Arguments: none +Arguments: lim Maximum amount to read/buffer Returns: the next character or EOF */ int -tls_getc(void) +tls_getc(unsigned lim) { -exim_gnutls_state_st *state = &state_server; -if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) - { - 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); - - if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); - inbytes = gnutls_record_recv(state->session, state->xfer_buffer, - ssl_xfer_buffer_size); - alarm(0); - - /* 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. */ +exim_gnutls_state_st * state = &state_server; - if (inbytes == 0) - { - DEBUG(D_tls) debug_printf("Got TLS_EOF\n"); +if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) + if (!tls_refill(lim)) + return state->xfer_error ? EOF : smtp_getc(lim); - receive_getc = smtp_getc; - receive_get_cache = smtp_get_cache; - receive_ungetc = smtp_ungetc; - receive_feof = smtp_feof; - receive_ferror = smtp_ferror; - receive_smtp_buffered = smtp_buffered; +/* Something in the buffer; return next uschar */ - gnutls_deinit(state->session); - state->session = NULL; - state->tlsp->active = -1; - state->tlsp->bits = 0; - state->tlsp->certificate_verified = FALSE; - tls_channelbinding_b64 = NULL; - state->tlsp->cipher = NULL; - state->tlsp->peercert = NULL; - state->tlsp->peerdn = NULL; - - return smtp_getc(); - } +return state->xfer_buffer[state->xfer_buffer_lwm++]; +} - /* Handle genuine errors */ +uschar * +tls_getbuf(unsigned * len) +{ +exim_gnutls_state_st * state = &state_server; +unsigned size; +uschar * buf; - else if (inbytes < 0) +if (state->xfer_buffer_lwm >= state->xfer_buffer_hwm) + if (!tls_refill(*len)) { - record_io_error(state, (int) inbytes, US"recv", NULL); - state->xfer_error = 1; - return EOF; + if (!state->xfer_error) return smtp_getbuf(len); + *len = 0; + return NULL; } -#ifndef DISABLE_DKIM - dkim_exim_verify_feed(state->xfer_buffer, inbytes); -#endif - state->xfer_buffer_hwm = (int) inbytes; - state->xfer_buffer_lwm = 0; - } - -/* Something in the buffer; return next uschar */ -return state->xfer_buffer[state->xfer_buffer_lwm++]; +if ((size = state->xfer_buffer_hwm - state->xfer_buffer_lwm) > *len) + size = *len; +buf = &state->xfer_buffer[state->xfer_buffer_lwm]; +state->xfer_buffer_lwm += size; +*len = size; +return buf; } + void tls_get_cache() { @@ -2231,6 +2795,14 @@ if (n > 0) } +BOOL +tls_could_read(void) +{ +return state_server.xfer_buffer_lwm < state_server.xfer_buffer_hwm + || gnutls_record_check_pending(state_server.session) > 0; +} + + /************************************************* @@ -2241,17 +2813,18 @@ if (n > 0) 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) @@ -2267,13 +2840,20 @@ 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; } @@ -2287,31 +2867,43 @@ 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 Returns: the number of bytes after a successful write, -1 after a failed write */ int -tls_write(BOOL is_server, const uschar *buff, size_t len) +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; + +if (more && !corked) gnutls_record_cork(state->session); +#endif + +DEBUG(D_tls) debug_printf("%s(%p, " SIZE_T_FMT "%s)\n", __FUNCTION__, + buff, left, more ? ", more" : ""); -DEBUG(D_tls) debug_printf("tls_do_write(%p, " SIZE_T_FMT ")\n", buff, left); 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; } @@ -2333,6 +2925,14 @@ if (len > INT_MAX) len = INT_MAX; } +#ifdef SUPPORT_CORK +if (more != corked) + { + if (!more) (void) gnutls_record_uncork(state->session, 0); + corked = more; + } +#endif + return (int) len; } @@ -2360,7 +2960,6 @@ vaguely_random_number(int max) { unsigned int r; int i, needed_len; -uschar *p; uschar smallbuf[sizeof(r)]; if (max <= 1) @@ -2368,7 +2967,8 @@ 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; @@ -2382,11 +2982,8 @@ 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. */ @@ -2420,6 +3017,7 @@ int rc; uschar *expciphers = NULL; gnutls_priority_t priority_cache; const char *errpos; +uschar * dummy_errstr; #define validate_check_rc(Label) do { \ if (rc != GNUTLS_E_SUCCESS) { if (exim_gnutls_base_init_done) gnutls_global_deinit(); \ @@ -2444,7 +3042,8 @@ exim_gnutls_base_init_done = TRUE; if (!(tls_require_ciphers && *tls_require_ciphers)) return_deinit(NULL); -if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers)) +if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers, + &dummy_errstr)) return_deinit(US"failed to expand tls_require_ciphers"); if (!(expciphers && *expciphers))