X-Git-Url: https://git.exim.org/users/jgh/exim.git/blobdiff_plain/5130845bf966ffc7a531dc3a9a99f24ea1e04588..d4e5e70b6c47bc30f9d6ce8300326ffc9fde79f1:/src/src/tls-openssl.c diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c index 43fbaa41a..392d59dd5 100644 --- a/src/src/tls-openssl.c +++ b/src/src/tls-openssl.c @@ -2,7 +2,7 @@ * Exim - an Internet mail transport agent * *************************************************/ -/* Copyright (c) University of Cambridge 1995 - 2014 */ +/* Copyright (c) University of Cambridge 1995 - 2017 */ /* See the file NOTICE for conditions of use and distribution. */ /* Portions Copyright (c) The OpenSSL Project 1999 */ @@ -22,6 +22,9 @@ functions from the OpenSSL library. */ #include #include #include +#ifndef OPENSSL_NO_ECDH +# include +#endif #ifndef DISABLE_OCSP # include #endif @@ -38,12 +41,51 @@ functions from the OpenSSL library. */ #if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT) # define EXIM_HAVE_OPENSSL_TLSEXT #endif -#if OPENSSL_VERSION_NUMBER >= 0x010100000L -# define EXIM_HAVE_OPENSSL_CHECKHOST +#if OPENSSL_VERSION_NUMBER >= 0x00908000L +# define EXIM_HAVE_RSA_GENKEY_EX +#endif +#if OPENSSL_VERSION_NUMBER >= 0x10100000L +# define EXIM_HAVE_OCSP_RESP_COUNT +#else +# define EXIM_HAVE_EPHEM_RSA_KEX +# define EXIM_HAVE_RAND_PSEUDO +#endif +#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) +# define EXIM_HAVE_SHA256 #endif -#if OPENSSL_VERSION_NUMBER >= 0x010000000L \ + +/* + * X509_check_host provides sane certificate hostname checking, but was added + * to OpenSSL late, after other projects forked off the code-base. So in + * addition to guarding against the base version number, beware that LibreSSL + * does not (at this time) support this function. + * + * If LibreSSL gains a different API, perhaps via libtls, then we'll probably + * opt to disentangle and ask a LibreSSL user to provide glue for a third + * crypto provider for libtls instead of continuing to tie the OpenSSL glue + * into even twistier knots. If LibreSSL gains the same API, we can just + * change this guard and punt the issue for a while longer. + */ +#ifndef LIBRESSL_VERSION_NUMBER +# if OPENSSL_VERSION_NUMBER >= 0x010100000L +# define EXIM_HAVE_OPENSSL_CHECKHOST +# endif +# if OPENSSL_VERSION_NUMBER >= 0x010000000L \ && (OPENSSL_VERSION_NUMBER & 0x0000ff000L) >= 0x000002000L -# define EXIM_HAVE_OPENSSL_CHECKHOST +# define EXIM_HAVE_OPENSSL_CHECKHOST +# endif +#endif + +#if !defined(LIBRESSL_VERSION_NUMBER) \ + || LIBRESSL_VERSION_NUMBER >= 0x20010000L +# if !defined(OPENSSL_NO_ECDH) +# if OPENSSL_VERSION_NUMBER >= 0x0090800fL +# define EXIM_HAVE_ECDH +# endif +# if OPENSSL_VERSION_NUMBER >= 0x10002000L +# define EXIM_HAVE_OPENSSL_EC_NIST2NID +# endif +# endif #endif #if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP) @@ -106,6 +148,7 @@ typedef struct tls_ext_ctx_cb { uschar *privatekey; #ifndef DISABLE_OCSP BOOL is_server; + STACK_OF(X509) *verify_stack; /* chain for verifying the proof */ union { struct { uschar *file; @@ -123,11 +166,8 @@ typedef struct tls_ext_ctx_cb { uschar *server_cipher_list; /* only passed down to tls_error: */ host_item *host; - -#ifdef EXPERIMENTAL_CERTNAMES - uschar * verify_cert_hostnames; -#endif -#ifdef EXPERIMENTAL_EVENT + const uschar * verify_cert_hostnames; +#ifndef DISABLE_EVENT uschar * event_action; #endif } tls_ext_ctx_cb; @@ -172,7 +212,7 @@ Returns: OK/DEFER/FAIL */ static int -tls_error(uschar * prefix, const host_item * host, uschar * msg) +tls_error(uschar * prefix, const host_item * host, uschar * msg) { if (!msg) { @@ -200,6 +240,7 @@ else +#ifdef EXIM_HAVE_EPHEM_RSA_KEX /************************************************* * Callback to generate RSA key * *************************************************/ @@ -217,10 +258,22 @@ static RSA * rsa_callback(SSL *s, int export, int keylength) { RSA *rsa_key; +#ifdef EXIM_HAVE_RSA_GENKEY_EX +BIGNUM *bn = BN_new(); +#endif + export = export; /* Shut picky compilers up */ DEBUG(D_tls) debug_printf("Generating %d bit RSA key...\n", keylength); -rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL); -if (rsa_key == NULL) + +#ifdef EXIM_HAVE_RSA_GENKEY_EX +if ( !BN_set_word(bn, (unsigned long)RSA_F4) + || !(rsa_key = RSA_new()) + || !RSA_generate_key_ex(rsa_key, keylength, bn, NULL) + ) +#else +if (!(rsa_key = RSA_generate_key(keylength, RSA_F4, NULL, NULL))) +#endif + { ERR_error_string(ERR_get_error(), ssl_errstring); log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s", @@ -229,6 +282,7 @@ if (rsa_key == NULL) } return rsa_key; } +#endif @@ -248,6 +302,7 @@ for(i= 0; idata.x509; X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name)); + name[sizeof(name)-1] = '\0'; debug_printf(" %s\n", name); } } @@ -256,21 +311,59 @@ for(i= 0; ievent_action : event_action; +if (ev) + { + DEBUG(D_tls) debug_printf("verify_event: %s %d\n", what, depth); + old_cert = tlsp->peercert; + tlsp->peercert = X509_dup(cert); + /* NB we do not bother setting peerdn */ + if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth)))) + { + log_write(0, LOG_MAIN, "[%s] %s verify denied by event-action: " + "depth=%d cert=%s: %s", + tlsp == &tls_out ? deliver_host_address : sender_host_address, + what, depth, dn, yield); + *calledp = TRUE; + if (!*optionalp) + { + if (old_cert) tlsp->peercert = old_cert; /* restore 1st failing cert */ + return 1; /* reject (leaving peercert set) */ + } + DEBUG(D_tls) debug_printf("Event-action verify failure overridden " + "(host in tls_try_verify_hosts)\n"); + } + X509_free(tlsp->peercert); + tlsp->peercert = old_cert; + } +return 0; +} +#endif + /************************************************* * Callback for verification * *************************************************/ /* The SSL library does certificate verification if set up to do so. This callback has the current yes/no state is in "state". If verification succeeded, -we set up the tls_peerdn string. If verification failed, what happens depends -on whether the client is required to present a verifiable certificate or not. +we set the certificate-verified flag. If verification failed, what happens +depends on whether the client is required to present a verifiable certificate +or not. If verification is optional, we change the state to yes, but still log the verification error. For some reason (it really would help to have proper documentation of OpenSSL), this callback function then gets called again, this -time with state = 1. In fact, that's useful, because we can set up the peerdn -value, but we must take care not to set the private verified flag on the second -time through. +time with state = 1. We must take care not to set the private verified flag on +the second time through. Note: this function is not called if the client fails to present a certificate when asked. We get here only if a certificate has been received. Handling of @@ -281,38 +374,39 @@ May be called multiple times for different issues with a certificate, even for a given "depth" in the certificate chain. Arguments: - state current yes/no state as 1/0 - x509ctx certificate information. - client TRUE for client startup, FALSE for server startup + preverify_ok current yes/no state as 1/0 + x509ctx certificate information. + tlsp per-direction (client vs. server) support data + calledp has-been-called flag + optionalp verification-is-optional flag -Returns: 1 if verified, 0 if not +Returns: 0 if verification should fail, otherwise 1 */ static int -verify_callback(int state, X509_STORE_CTX *x509ctx, +verify_callback(int preverify_ok, X509_STORE_CTX *x509ctx, tls_support *tlsp, BOOL *calledp, BOOL *optionalp) { X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); int depth = X509_STORE_CTX_get_error_depth(x509ctx); -static uschar txt[256]; -#ifdef EXPERIMENTAL_EVENT -uschar * ev; -uschar * yield; -#endif +uschar dn[256]; -X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt)); +X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)); +dn[sizeof(dn)-1] = '\0'; -if (state == 0) +if (preverify_ok == 0) { - log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s", + log_write(0, LOG_MAIN, "[%s] SSL verify error: depth=%d error=%s cert=%s", + tlsp == &tls_out ? deliver_host_address : sender_host_address, depth, X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), - txt); + dn); *calledp = TRUE; if (!*optionalp) { - tlsp->peercert = X509_dup(cert); - return 0; /* reject */ + if (!tlsp->peercert) + tlsp->peercert = X509_dup(cert); /* record failing cert */ + return 0; /* reject */ } DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " "tls_try_verify_hosts)\n"); @@ -320,118 +414,86 @@ if (state == 0) else if (depth != 0) { - DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, txt); + DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d SN=%s\n", depth, dn); #ifndef DISABLE_OCSP if (tlsp == &tls_out && client_static_cbinfo->u_ocsp.client.verify_store) { /* client, wanting stapling */ /* Add the server cert's signing chain as the one for the verification of the OCSP stapled information. */ - + if (!X509_STORE_add_cert(client_static_cbinfo->u_ocsp.client.verify_store, cert)) ERR_clear_error(); + sk_X509_push(client_static_cbinfo->verify_stack, cert); } #endif -#ifdef EXPERIMENTAL_EVENT - ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action; - if (ev) - { - tlsp->peercert = X509_dup(cert); - if ((yield = event_raise(ev, US"tls:cert", string_sprintf("%d", depth)))) - { - log_write(0, LOG_MAIN, "SSL verify denied by event-action: " - "depth=%d cert=%s: %s", depth, txt, yield); - *calledp = TRUE; - if (!*optionalp) - return 0; /* reject */ - DEBUG(D_tls) debug_printf("Event-action verify failure overridden " - "(host in tls_try_verify_hosts)\n"); - } - X509_free(tlsp->peercert); - tlsp->peercert = NULL; - } +#ifndef DISABLE_EVENT + if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) + return 0; /* reject, with peercert set */ #endif } else { -#ifdef EXPERIMENTAL_CERTNAMES - uschar * verify_cert_hostnames; -#endif - - tlsp->peerdn = txt; - tlsp->peercert = X509_dup(cert); + const uschar * verify_cert_hostnames; -#ifdef EXPERIMENTAL_CERTNAMES if ( tlsp == &tls_out && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames))) /* client, wanting hostname check */ - -# if EXIM_HAVE_OPENSSL_CHECKHOST -# ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS -# define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 -# endif -# ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS -# define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0 -# endif { + +#ifdef EXIM_HAVE_OPENSSL_CHECKHOST +# ifndef X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS +# define X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS 0 +# endif +# ifndef X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS +# define X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS 0 +# endif int sep = 0; - uschar * list = verify_cert_hostnames; + const uschar * list = verify_cert_hostnames; uschar * name; int rc; while ((name = string_nextinlist(&list, &sep, NULL, 0))) - if ((rc = X509_check_host(cert, name, 0, + if ((rc = X509_check_host(cert, CCS name, 0, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS - | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS))) + | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS, + NULL))) { if (rc < 0) { - log_write(0, LOG_MAIN, "SSL verify error: internal error\n"); + log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error", + deliver_host_address); name = NULL; } break; } if (!name) - { - log_write(0, LOG_MAIN, - "SSL verify error: certificate name mismatch: \"%s\"\n", txt); - *calledp = TRUE; - if (!*optionalp) - return 0; /* reject */ - DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " - "tls_try_verify_hosts)\n"); - } - } -# else +#else if (!tls_is_name_for_cert(verify_cert_hostnames, cert)) +#endif { log_write(0, LOG_MAIN, - "SSL verify error: certificate name mismatch: \"%s\"\n", txt); + "[%s] SSL verify error: certificate name mismatch: " + "DN=\"%s\" H=\"%s\"", + deliver_host_address, dn, verify_cert_hostnames); *calledp = TRUE; if (!*optionalp) - return 0; /* reject */ + { + if (!tlsp->peercert) + tlsp->peercert = X509_dup(cert); /* record failing cert */ + return 0; /* reject */ + } DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in " "tls_try_verify_hosts)\n"); } -# endif -#endif /*EXPERIMENTAL_CERTNAMES*/ + } -#ifdef EXPERIMENTAL_EVENT - ev = tlsp == &tls_out ? client_static_cbinfo->event_action : event_action; - if (ev) - if ((yield = event_raise(ev, US"tls:cert", US"0"))) - { - log_write(0, LOG_MAIN, "SSL verify denied by event-action: " - "depth=0 cert=%s: %s", txt, yield); - *calledp = TRUE; - if (!*optionalp) - return 0; /* reject */ - DEBUG(D_tls) debug_printf("Event-action verify failure overridden " - "(host in tls_try_verify_hosts)\n"); - } +#ifndef DISABLE_EVENT + if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL")) + return 0; /* reject, with peercert set */ #endif DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n", - *calledp ? "" : " authenticated", txt); + *calledp ? "" : " authenticated", dn); if (!*calledp) tlsp->certificate_verified = TRUE; *calledp = TRUE; } @@ -440,15 +502,17 @@ return 1; /* accept, at least for this level */ } static int -verify_callback_client(int state, X509_STORE_CTX *x509ctx) +verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx) { -return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional); +return verify_callback(preverify_ok, x509ctx, &tls_out, + &client_verify_callback_called, &client_verify_optional); } static int -verify_callback_server(int state, X509_STORE_CTX *x509ctx) +verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx) { -return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional); +return verify_callback(preverify_ok, x509ctx, &tls_in, + &server_verify_callback_called, &server_verify_optional); } @@ -458,44 +522,39 @@ return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, itself. */ static int -verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx) +verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx) { X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx); -static uschar txt[256]; -#ifdef EXPERIMENTAL_EVENT +uschar dn[256]; int depth = X509_STORE_CTX_get_error_depth(x509ctx); -uschar * yield; +#ifndef DISABLE_EVENT +BOOL dummy_called, optional = FALSE; #endif -X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt)); +X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)); +dn[sizeof(dn)-1] = '\0'; -DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s\n", txt); -tls_out.peerdn = txt; -tls_out.peercert = X509_dup(cert); +DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n", + preverify_ok ? "ok":"BAD", depth, dn); -#ifdef EXPERIMENTAL_EVENT - if (client_static_cbinfo->event_action) - { - if ((yield = event_raise(client_static_cbinfo->event_action, - US"tls:cert", string_sprintf("%d", depth)))) - { - log_write(0, LOG_MAIN, "DANE verify denied by event-action: " - "depth=%d cert=%s: %s", depth, txt, yield); - tls_out.certificate_verified = FALSE; - return 0; /* reject */ - } - if (depth != 0) - { - X509_free(tls_out.peercert); - tls_out.peercert = NULL; - } - } +#ifndef DISABLE_EVENT + if (verify_event(&tls_out, cert, depth, dn, + &dummy_called, &optional, US"DANE")) + return 0; /* reject, with peercert set */ #endif -if (state == 1) +if (preverify_ok == 1) tls_out.dane_verified = tls_out.certificate_verified = TRUE; -return 1; +else + { + int err = X509_STORE_CTX_get_error(x509ctx); + DEBUG(D_tls) + debug_printf(" - err %d '%s'\n", err, X509_verify_cert_error_string(err)); + if (err == X509_V_ERR_APPLICATION_VERIFICATION) + preverify_ok = 1; + } +return preverify_ok; } #endif /*EXPERIMENTAL_DANE*/ @@ -534,6 +593,7 @@ DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s)); /* If dhparam is set, expand it, and load up the parameters for DH encryption. Arguments: + sctx The current SSL CTX (inbound or outbound) dhparam DH parameter file or fixed parameter identity string host connected host, if client; NULL if server @@ -613,11 +673,127 @@ return TRUE; +/************************************************* +* Initialize for ECDH * +*************************************************/ + +/* Load parameters for ECDH encryption. + +For now, we stick to NIST P-256 because: it's simple and easy to configure; +it avoids any patent issues that might bite redistributors; despite events in +the news and concerns over curve choices, we're not cryptographers, we're not +pretending to be, and this is "good enough" to be better than no support, +protecting against most adversaries. Given another year or two, there might +be sufficient clarity about a "right" way forward to let us make an informed +decision, instead of a knee-jerk reaction. + +Longer-term, we should look at supporting both various named curves and +external files generated with "openssl ecparam", much as we do for init_dh(). +We should also support "none" as a value, to explicitly avoid initialisation. + +Patches welcome. + +Arguments: + sctx The current SSL CTX (inbound or outbound) + host connected host, if client; NULL if server + +Returns: TRUE if OK (nothing to set up, or setup worked) +*/ + +static BOOL +init_ecdh(SSL_CTX * sctx, host_item * host) +{ +#ifdef OPENSSL_NO_ECDH +return TRUE; +#else + +EC_KEY * ecdh; +uschar * exp_curve; +int nid; +BOOL rv; + +if (host) /* No ECDH setup for clients, only for servers */ + return TRUE; + +# ifndef EXIM_HAVE_ECDH +DEBUG(D_tls) + debug_printf("No OpenSSL API to define ECDH parameters, skipping\n"); +return TRUE; +# else + +if (!expand_check(tls_eccurve, US"tls_eccurve", &exp_curve)) + return FALSE; +if (!exp_curve || !*exp_curve) + return TRUE; + +/* "auto" needs to be handled carefully. + * OpenSSL < 1.0.2: we do not select anything, but fallback to prime256v1 + * OpenSSL < 1.1.0: we have to call SSL_CTX_set_ecdh_auto + * (openssl/ssl.h defines SSL_CTRL_SET_ECDH_AUTO) + * OpenSSL >= 1.1.0: we do not set anything, the libray does autoselection + * https://github.com/openssl/openssl/commit/fe6ef2472db933f01b59cad82aa925736935984b + */ +if (Ustrcmp(exp_curve, "auto") == 0) + { +#if OPENSSL_VERSION_NUMBER < 0x10002000L + DEBUG(D_tls) debug_printf( + "ECDH OpenSSL < 1.0.2: temp key parameter settings: overriding \"auto\" with \"prime256v1\"\n"); + exp_curve = "prime256v1"; +#else +# if defined SSL_CTRL_SET_ECDH_AUTO + DEBUG(D_tls) debug_printf( + "ECDH OpenSSL 1.0.2+ temp key parameter settings: autoselection\n"); + SSL_CTX_set_ecdh_auto(sctx, 1); + return TRUE; +# else + DEBUG(D_tls) debug_printf( + "ECDH OpenSSL 1.1.0+ temp key parameter settings: default selection\n"); + return TRUE; +# endif +#endif + } + +DEBUG(D_tls) debug_printf("ECDH: curve '%s'\n", exp_curve); +if ( (nid = OBJ_sn2nid (CCS exp_curve)) == NID_undef +# ifdef EXIM_HAVE_OPENSSL_EC_NIST2NID + && (nid = EC_curve_nist2nid(CCS exp_curve)) == NID_undef +# endif + ) + { + tls_error(string_sprintf("Unknown curve name tls_eccurve '%s'", + exp_curve), + host, NULL); + return FALSE; + } + +if (!(ecdh = EC_KEY_new_by_curve_name(nid))) + { + tls_error(US"Unable to create ec curve", host, NULL); + return FALSE; + } + +/* The "tmp" in the name here refers to setting a temporary key +not to the stability of the interface. */ + +if ((rv = SSL_CTX_set_tmp_ecdh(sctx, ecdh) == 0)) + tls_error(string_sprintf("Error enabling '%s' curve", exp_curve), host, NULL); +else + DEBUG(D_tls) debug_printf("ECDH: enabled '%s' curve\n", exp_curve); + +EC_KEY_free(ecdh); +return !rv; + +# endif /*EXIM_HAVE_ECDH*/ +#endif /*OPENSSL_NO_ECDH*/ +} + + + + #ifndef DISABLE_OCSP /************************************************* * Load OCSP information into state * *************************************************/ - /* Called to load the server OCSP response from the given file into memory, once caller has determined this is needed. Checks validity. Debugs a message if invalid. @@ -634,12 +810,12 @@ Arguments: static void ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded) { -BIO *bio; -OCSP_RESPONSE *resp; -OCSP_BASICRESP *basic_response; -OCSP_SINGLERESP *single_response; -ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd; -X509_STORE *store; +BIO * bio; +OCSP_RESPONSE * resp; +OCSP_BASICRESP * basic_response; +OCSP_SINGLERESP * single_response; +ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd; +STACK_OF(X509) * sk; unsigned long verify_flags; int status, reason, i; @@ -650,8 +826,7 @@ if (cbinfo->u_ocsp.server.response) cbinfo->u_ocsp.server.response = NULL; } -bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb"); -if (!bio) +if (!(bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb"))) { DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n", cbinfo->u_ocsp.server.file_expanded); @@ -666,33 +841,54 @@ if (!resp) return; } -status = OCSP_response_status(resp); -if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL) +if ((status = OCSP_response_status(resp)) != OCSP_RESPONSE_STATUS_SUCCESSFUL) { DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n", OCSP_response_status_str(status), status); goto bad; } -basic_response = OCSP_response_get1_basic(resp); -if (!basic_response) +if (!(basic_response = OCSP_response_get1_basic(resp))) { DEBUG(D_tls) debug_printf("OCSP response parse error: unable to extract basic response.\n"); goto bad; } -store = SSL_CTX_get_cert_store(sctx); +sk = cbinfo->verify_stack; verify_flags = OCSP_NOVERIFY; /* check sigs, but not purpose */ /* May need to expose ability to adjust those flags? OCSP_NOSIGS OCSP_NOVERIFY OCSP_NOCHAIN OCSP_NOCHECKS OCSP_NOEXPLICIT OCSP_TRUSTOTHER OCSP_NOINTERN */ -i = OCSP_basic_verify(basic_response, NULL, store, verify_flags); -if (i <= 0) +/* This does a full verify on the OCSP proof before we load it for serving +up; possibly overkill - just date-checks might be nice enough. + +OCSP_basic_verify takes a "store" arg, but does not +use it for the chain verification, which is all we do +when OCSP_NOVERIFY is set. The content from the wire +"basic_response" and a cert-stack "sk" are all that is used. + +We have a stack, loaded in setup_certs() if tls_verify_certificates +was a file (not a directory, or "system"). It is unfortunate we +cannot used the connection context store, as that would neatly +handle the "system" case too, but there seems to be no library +function for getting a stack from a store. +[ In OpenSSL 1.1 - ? X509_STORE_CTX_get0_chain(ctx) ? ] +We do not free the stack since it could be needed a second time for +SNI handling. + +Separately we might try to replace using OCSP_basic_verify() - which seems to not +be a public interface into the OpenSSL library (there's no manual entry) - +But what with? We also use OCSP_basic_verify in the client stapling callback. +And there we NEED it; we must verify that status... unless the +library does it for us anyway? */ + +if ((i = OCSP_basic_verify(basic_response, sk, NULL, verify_flags)) < 0) { - DEBUG(D_tls) { + DEBUG(D_tls) + { ERR_error_string(ERR_get_error(), ssl_errstring); debug_printf("OCSP response verify failure: %s\n", US ssl_errstring); } @@ -706,8 +902,8 @@ proves false, we need to extract a cert id from our issued cert right cert in the stack and then calls OCSP_single_get0_status()). I'm hoping to avoid reworking a bunch more of how we handle state here. */ -single_response = OCSP_resp_get0(basic_response, 0); -if (!single_response) + +if (!(single_response = OCSP_resp_get0(basic_response, 0))) { DEBUG(D_tls) debug_printf("Unable to get first response from OCSP basic response.\n"); @@ -738,7 +934,7 @@ bad: { extern char ** environ; uschar ** p; - for (p = USS environ; *p != NULL; p++) + if (environ) for (p = USS environ; *p != NULL; p++) if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0) { DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n"); @@ -752,6 +948,73 @@ return; +/* Create and install a selfsigned certificate, for use in server mode */ + +static int +tls_install_selfsign(SSL_CTX * sctx) +{ +X509 * x509 = NULL; +EVP_PKEY * pkey; +RSA * rsa; +X509_NAME * name; +uschar * where; + +where = US"allocating pkey"; +if (!(pkey = EVP_PKEY_new())) + goto err; + +where = US"allocating cert"; +if (!(x509 = X509_new())) + goto err; + +where = US"generating pkey"; + /* deprecated, use RSA_generate_key_ex() */ +if (!(rsa = RSA_generate_key(1024, RSA_F4, NULL, NULL))) + goto err; + +where = US"assigning pkey"; +if (!EVP_PKEY_assign_RSA(pkey, rsa)) + goto err; + +X509_set_version(x509, 2); /* N+1 - version 3 */ +ASN1_INTEGER_set(X509_get_serialNumber(x509), 0); +X509_gmtime_adj(X509_get_notBefore(x509), 0); +X509_gmtime_adj(X509_get_notAfter(x509), (long)60 * 60); /* 1 hour */ +X509_set_pubkey(x509, pkey); + +name = X509_get_subject_name(x509); +X509_NAME_add_entry_by_txt(name, "C", + MBSTRING_ASC, CUS "UK", -1, -1, 0); +X509_NAME_add_entry_by_txt(name, "O", + MBSTRING_ASC, CUS "Exim Developers", -1, -1, 0); +X509_NAME_add_entry_by_txt(name, "CN", + MBSTRING_ASC, CUS smtp_active_hostname, -1, -1, 0); +X509_set_issuer_name(x509, name); + +where = US"signing cert"; +if (!X509_sign(x509, pkey, EVP_md5())) + goto err; + +where = US"installing selfsign cert"; +if (!SSL_CTX_use_certificate(sctx, x509)) + goto err; + +where = US"installing selfsign key"; +if (!SSL_CTX_use_PrivateKey(sctx, pkey)) + goto err; + +return OK; + +err: + (void) tls_error(where, NULL, NULL); + if (x509) X509_free(x509); + if (pkey) EVP_PKEY_free(pkey); + return DEFER; +} + + + + /************************************************* * Expand key and cert file specs * *************************************************/ @@ -772,60 +1035,67 @@ tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo) { uschar *expanded; -if (cbinfo->certificate == NULL) - return OK; - -if (Ustrstr(cbinfo->certificate, US"tls_sni") || - Ustrstr(cbinfo->certificate, US"tls_in_sni") || - Ustrstr(cbinfo->certificate, US"tls_out_sni") - ) - reexpand_tls_files_for_sni = TRUE; - -if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded)) - return DEFER; - -if (expanded != NULL) +if (!cbinfo->certificate) { - DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); - if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) - return tls_error(string_sprintf( - "SSL_CTX_use_certificate_chain_file file=%s", expanded), - cbinfo->host, NULL); + if (cbinfo->host) /* client */ + return OK; + /* server */ + if (tls_install_selfsign(sctx) != OK) + return DEFER; } +else + { + if (Ustrstr(cbinfo->certificate, US"tls_sni") || + Ustrstr(cbinfo->certificate, US"tls_in_sni") || + Ustrstr(cbinfo->certificate, US"tls_out_sni") + ) + reexpand_tls_files_for_sni = TRUE; -if (cbinfo->privatekey != NULL && - !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded)) - return DEFER; + if (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded)) + return DEFER; -/* If expansion was forced to fail, key_expanded will be NULL. If the result -of the expansion is an empty string, ignore it also, and assume the private -key is in the same file as the certificate. */ + if (expanded != NULL) + { + DEBUG(D_tls) debug_printf("tls_certificate file %s\n", expanded); + if (!SSL_CTX_use_certificate_chain_file(sctx, CS expanded)) + return tls_error(string_sprintf( + "SSL_CTX_use_certificate_chain_file file=%s", expanded), + cbinfo->host, NULL); + } -if (expanded != NULL && *expanded != 0) - { - DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); - if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) - return tls_error(string_sprintf( - "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL); + if (cbinfo->privatekey != NULL && + !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded)) + return DEFER; + + /* If expansion was forced to fail, key_expanded will be NULL. If the result + of the expansion is an empty string, ignore it also, and assume the private + key is in the same file as the certificate. */ + + if (expanded && *expanded) + { + DEBUG(D_tls) debug_printf("tls_privatekey file %s\n", expanded); + if (!SSL_CTX_use_PrivateKey_file(sctx, CS expanded, SSL_FILETYPE_PEM)) + return tls_error(string_sprintf( + "SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL); + } } #ifndef DISABLE_OCSP -if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL) +if (cbinfo->is_server && cbinfo->u_ocsp.server.file) { if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded)) return DEFER; - if (expanded != NULL && *expanded != 0) + if (expanded && *expanded) { DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded); - if (cbinfo->u_ocsp.server.file_expanded && - (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0)) + if ( cbinfo->u_ocsp.server.file_expanded + && (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0)) { - DEBUG(D_tls) - debug_printf("tls_ocsp_file value unchanged, using existing values.\n"); - } else { - ocsp_load_response(sctx, cbinfo, expanded); + DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n"); } + else + ocsp_load_response(sctx, cbinfo, expanded); } } #endif @@ -896,6 +1166,12 @@ SSL_CTX_set_options(server_sni, SSL_CTX_get_options(server_ctx)); SSL_CTX_set_timeout(server_sni, SSL_CTX_get_timeout(server_ctx)); SSL_CTX_set_tlsext_servername_callback(server_sni, tls_servername_cb); SSL_CTX_set_tlsext_servername_arg(server_sni, cbinfo); + +if ( !init_dh(server_sni, cbinfo->dhparam, NULL) + || !init_ecdh(server_sni, NULL) + ) + return SSL_TLSEXT_ERR_NOACK; + if (cbinfo->server_cipher_list) SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list); #ifndef DISABLE_OCSP @@ -906,15 +1182,13 @@ if (cbinfo->u_ocsp.server.file) } #endif -rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server); -if (rc != OK) return SSL_TLSEXT_ERR_NOACK; +if ((rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, + verify_callback_server)) != OK) + return SSL_TLSEXT_ERR_NOACK; /* do this after setup_certs, because this can require the certs for verifying OCSP information. */ -rc = tls_expand_session_files(server_sni, cbinfo); -if (rc != OK) return SSL_TLSEXT_ERR_NOACK; - -if (!init_dh(server_sni, cbinfo->dhparam, NULL)) +if ((rc = tls_expand_session_files(server_sni, cbinfo)) != OK) return SSL_TLSEXT_ERR_NOACK; DEBUG(D_tls) debug_printf("Switching SSL context.\n"); @@ -949,7 +1223,7 @@ uschar *response_der; int response_der_len; DEBUG(D_tls) - debug_printf("Received TLS status request (OCSP stapling); %s response.", + debug_printf("Received TLS status request (OCSP stapling); %s response\n", cbinfo->u_ocsp.server.response ? "have" : "lack"); tls_in.ocsp = OCSP_NOT_RESP; @@ -991,8 +1265,7 @@ len = SSL_get_tlsext_status_ocsp_resp(s, &p); if(!p) { /* Expect this when we requested ocsp but got none */ - if ( cbinfo->u_ocsp.client.verify_required - && log_extra_selector & LX_tls_cipher) + if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher)) log_write(0, LOG_MAIN, "Received TLS status callback, null content"); else DEBUG(D_tls) debug_printf(" null\n"); @@ -1002,7 +1275,7 @@ if(!p) if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) { tls_out.ocsp = OCSP_FAILED; - if (log_extra_selector & LX_tls_cipher) + if (LOGGING(tls_cipher)) log_write(0, LOG_MAIN, "Received TLS cert status response, parse error"); else DEBUG(D_tls) debug_printf(" parse error\n"); @@ -1012,7 +1285,7 @@ if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len))) if(!(bs = OCSP_response_get1_basic(rsp))) { tls_out.ocsp = OCSP_FAILED; - if (log_extra_selector & LX_tls_cipher) + if (LOGGING(tls_cipher)) log_write(0, LOG_MAIN, "Received TLS cert status response, error parsing response"); else DEBUG(D_tls) debug_printf(" error parsing response\n"); @@ -1039,31 +1312,41 @@ if(!(bs = OCSP_response_get1_basic(rsp))) /* Use the chain that verified the server cert to verify the stapled info */ /* DEBUG(D_tls) x509_store_dump_cert_s_names(cbinfo->u_ocsp.client.verify_store); */ - if ((i = OCSP_basic_verify(bs, NULL, + if ((i = OCSP_basic_verify(bs, cbinfo->verify_stack, cbinfo->u_ocsp.client.verify_store, 0)) <= 0) { tls_out.ocsp = OCSP_FAILED; - if (log_extra_selector & LX_tls_cipher) + if (LOGGING(tls_cipher)) log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable"); BIO_printf(bp, "OCSP response verify failure\n"); ERR_print_errors(bp); - i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; - goto out; + goto failed; } BIO_printf(bp, "OCSP response well-formed and signed OK\n"); + /*XXX So we have a good stapled OCSP status. How do we know + it is for the cert of interest? OpenSSL 1.1.0 has a routine + OCSP_resp_find_status() which matches on a cert id, which presumably + we should use. Making an id needs OCSP_cert_id_new(), which takes + issuerName, issuerKey, serialNumber. Are they all in the cert? + + For now, carry on blindly accepting the resp. */ + { - STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; OCSP_SINGLERESP * single; +#ifdef EXIM_HAVE_OCSP_RESP_COUNT + if (OCSP_resp_count(bs) != 1) +#else + STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses; if (sk_OCSP_SINGLERESP_num(sresp) != 1) +#endif { tls_out.ocsp = OCSP_FAILED; log_write(0, LOG_MAIN, "OCSP stapling " "with multiple responses not handled"); - i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; - goto out; + goto failed; } single = OCSP_resp_get0(bs, 0); status = OCSP_single_get0_status(single, &reason, &rev, @@ -1078,7 +1361,6 @@ if(!(bs = OCSP_response_get1_basic(rsp))) tls_out.ocsp = OCSP_FAILED; DEBUG(D_tls) ERR_print_errors(bp); log_write(0, LOG_MAIN, "Server OSCP dates invalid"); - i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; } else { @@ -1089,24 +1371,24 @@ if(!(bs = OCSP_response_get1_basic(rsp))) case V_OCSP_CERTSTATUS_GOOD: tls_out.ocsp = OCSP_VFIED; i = 1; - break; + goto good; case V_OCSP_CERTSTATUS_REVOKED: tls_out.ocsp = OCSP_FAILED; log_write(0, LOG_MAIN, "Server certificate revoked%s%s", reason != -1 ? "; reason: " : "", reason != -1 ? OCSP_crl_reason_str(reason) : ""); DEBUG(D_tls) time_print(bp, "Revocation Time", rev); - i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; break; default: tls_out.ocsp = OCSP_FAILED; log_write(0, LOG_MAIN, "Server certificate status unknown, in OCSP stapling"); - i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; break; } } - out: + failed: + i = cbinfo->u_ocsp.client.verify_required ? 0 : 1; + good: BIO_free(bp); } @@ -1153,6 +1435,7 @@ cbinfo = store_malloc(sizeof(tls_ext_ctx_cb)); cbinfo->certificate = certificate; cbinfo->privatekey = privatekey; #ifndef DISABLE_OCSP +cbinfo->verify_stack = NULL; if ((cbinfo->is_server = host==NULL)) { cbinfo->u_ocsp.server.file = ocsp_file; @@ -1165,14 +1448,14 @@ else cbinfo->dhparam = dhparam; cbinfo->server_cipher_list = NULL; cbinfo->host = host; -#ifdef EXPERIMENTAL_EVENT +#ifndef DISABLE_EVENT cbinfo->event_action = NULL; #endif SSL_load_error_strings(); /* basic set up */ OpenSSL_add_ssl_algorithms(); -#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256) +#ifdef EXIM_HAVE_SHA256 /* SHA256 is becoming ever more popular. This makes sure it gets added to the list of available digests. */ EVP_add_digest(EVP_sha256()); @@ -1186,10 +1469,9 @@ when OpenSSL is built without SSLv2 support. By disabling with openssl_options, we can let admins re-enable with the existing knob. */ -*ctxp = SSL_CTX_new((host == NULL)? - SSLv23_server_method() : SSLv23_client_method()); +*ctxp = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method()); -if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL); +if (!*ctxp) return tls_error(US"SSL_CTX_new", host, NULL); /* It turns out that we need to seed the random number generator this early in order to get the full complement of ciphers to work. It took me roughly a day @@ -1217,7 +1499,7 @@ if (!RAND_status()) /* Set up the information callback, which outputs if debugging is at a suitable level. */ -SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback); +DEBUG(D_tls) SSL_CTX_set_info_callback(*ctxp, (void (*)())info_callback); /* Automatically re-try reads/writes after renegotiation. */ (void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY); @@ -1246,16 +1528,29 @@ else DEBUG(D_tls) debug_printf("no SSL CTX options to set\n"); /* Initialize with DH parameters if supplied */ +/* Initialize ECDH temp key parameter selection */ -if (!init_dh(*ctxp, dhparam, host)) return DEFER; +if ( !init_dh(*ctxp, dhparam, host) + || !init_ecdh(*ctxp, host) + ) + return DEFER; /* Set up certificate and key (and perhaps OCSP info) */ -rc = tls_expand_session_files(*ctxp, cbinfo); -if (rc != OK) return rc; +if ((rc = tls_expand_session_files(*ctxp, cbinfo)) != OK) + return rc; + +/* If we need to handle SNI or OCSP, do so */ -/* If we need to handle SNI, do so */ #ifdef EXIM_HAVE_OPENSSL_TLSEXT +# ifndef DISABLE_OCSP + if (!(cbinfo->verify_stack = sk_X509_new_null())) + { + DEBUG(D_tls) debug_printf("failed to create stack for stapling verify\n"); + return FAIL; + } +# endif + if (host == NULL) /* server */ { # ifndef DISABLE_OCSP @@ -1289,13 +1584,12 @@ else /* client */ # endif #endif -#ifdef EXPERIMENTAL_CERTNAMES cbinfo->verify_cert_hostnames = NULL; -#endif +#ifdef EXIM_HAVE_EPHEM_RSA_KEX /* Set up the RSA callback */ - SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback); +#endif /* Finally, set the timeout, and we are done */ @@ -1343,6 +1637,29 @@ DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); } +static void +peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned bsize) +{ +/*XXX we might consider a list-of-certs variable for the cert chain. +SSL_get_peer_cert_chain(SSL*). We'd need a new variable type and support +in list-handling functions, also consider the difference between the entire +chain and the elements sent by the peer. */ + +/* Will have already noted peercert on a verify fail; possibly not the leaf */ +if (!tlsp->peercert) + tlsp->peercert = SSL_get_peer_certificate(ssl); +/* Beware anonymous ciphers which lead to server_cert being NULL */ +if (tlsp->peercert) + { + X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, bsize); + peerdn[bsize-1] = '\0'; + tlsp->peerdn = peerdn; /*XXX a static buffer... */ + } +else + tlsp->peerdn = NULL; +} + + @@ -1350,6 +1667,23 @@ DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf); * Set up for verifying certificates * *************************************************/ +/* Load certs from file, return TRUE on success */ + +static BOOL +chain_from_pem_file(const uschar * file, STACK_OF(X509) * verify_stack) +{ +BIO * bp; +X509 * x; + +if (!(bp = BIO_new_file(CS file, "r"))) return FALSE; +while ((x = PEM_read_bio_X509(bp, NULL, 0, NULL))) + sk_X509_push(verify_stack, x); +BIO_free(bp); +return TRUE; +} + + + /* Called by both client and server startup Arguments: @@ -1373,71 +1707,96 @@ uschar *expcerts, *expcrl; if (!expand_check(certs, US"tls_verify_certificates", &expcerts)) return DEFER; -if (expcerts != NULL && *expcerts != '\0') +if (expcerts && *expcerts) { - struct stat statbuf; + /* Tell the library to use its compiled-in location for the system default + CA bundle. Then add the ones specified in the config, if any. */ + if (!SSL_CTX_set_default_verify_paths(sctx)) return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL); - if (Ustat(expcerts, &statbuf) < 0) + if (Ustrcmp(expcerts, "system") != 0) { - log_write(0, LOG_MAIN|LOG_PANIC, - "failed to stat %s for certificates", expcerts); - return DEFER; - } - else - { - uschar *file, *dir; - if ((statbuf.st_mode & S_IFMT) == S_IFDIR) - { file = NULL; dir = expcerts; } + struct stat statbuf; + + if (Ustat(expcerts, &statbuf) < 0) + { + log_write(0, LOG_MAIN|LOG_PANIC, + "failed to stat %s for certificates", expcerts); + return DEFER; + } else - { file = expcerts; dir = NULL; } - - /* If a certificate file is empty, the next function fails with an - unhelpful error message. If we skip it, we get the correct behaviour (no - certificates are recognized, but the error message is still misleading (it - says no certificate was supplied.) But this is better. */ - - if ((file == NULL || statbuf.st_size > 0) && - !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) - return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); - - /* Load the list of CAs for which we will accept certs, for sending - to the client. This is only for the one-file tls_verify_certificates - variant. - If a list isn't loaded into the server, but - some verify locations are set, the server end appears to make - a wildcard reqest for client certs. - Meanwhile, the client library as deafult behaviour *ignores* the list - we send over the wire - see man SSL_CTX_set_client_cert_cb. - Because of this, and that the dir variant is likely only used for - the public-CA bundle (not for a private CA), not worth fixing. - */ - if (file != NULL) { - STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file); -DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", - sk_X509_NAME_num(names)); - SSL_CTX_set_client_CA_list(sctx, names); + uschar *file, *dir; + if ((statbuf.st_mode & S_IFMT) == S_IFDIR) + { file = NULL; dir = expcerts; } + else + { + file = expcerts; dir = NULL; +#ifndef DISABLE_OCSP + /* In the server if we will be offering an OCSP proof, load chain from + file for verifying the OCSP proof at load time. */ + + if ( !host + && statbuf.st_size > 0 + && server_static_cbinfo->u_ocsp.server.file + && !chain_from_pem_file(file, server_static_cbinfo->verify_stack) + ) + { + log_write(0, LOG_MAIN|LOG_PANIC, + "failed to load cert hain from %s", file); + return DEFER; + } +#endif + } + + /* If a certificate file is empty, the next function fails with an + unhelpful error message. If we skip it, we get the correct behaviour (no + certificates are recognized, but the error message is still misleading (it + says no certificate was supplied). But this is better. */ + + if ( (!file || statbuf.st_size > 0) + && !SSL_CTX_load_verify_locations(sctx, CS file, CS dir)) + return tls_error(US"SSL_CTX_load_verify_locations", host, NULL); + + /* Load the list of CAs for which we will accept certs, for sending + to the client. This is only for the one-file tls_verify_certificates + variant. + If a list isn't loaded into the server, but + some verify locations are set, the server end appears to make + a wildcard request for client certs. + Meanwhile, the client library as default behaviour *ignores* the list + we send over the wire - see man SSL_CTX_set_client_cert_cb. + Because of this, and that the dir variant is likely only used for + the public-CA bundle (not for a private CA), not worth fixing. + */ + if (file) + { + STACK_OF(X509_NAME) * names = SSL_load_client_CA_file(CS file); + + DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", + sk_X509_NAME_num(names)); + SSL_CTX_set_client_CA_list(sctx, names); + } } } /* Handle a certificate revocation list. */ - #if OPENSSL_VERSION_NUMBER > 0x00907000L +#if OPENSSL_VERSION_NUMBER > 0x00907000L /* This bit of code is now the version supplied by Lars Mainka. (I have - * merely reformatted it into the Exim code style.) + merely reformatted it into the Exim code style.) - * "From here I changed the code to add support for multiple crl's - * in pem format in one file or to support hashed directory entries in - * pem format instead of a file. This method now uses the library function - * X509_STORE_load_locations to add the CRL location to the SSL context. - * OpenSSL will then handle the verify against CA certs and CRLs by - * itself in the verify callback." */ + "From here I changed the code to add support for multiple crl's + in pem format in one file or to support hashed directory entries in + pem format instead of a file. This method now uses the library function + X509_STORE_load_locations to add the CRL location to the SSL context. + OpenSSL will then handle the verify against CA certs and CRLs by + itself in the verify callback." */ if (!expand_check(crl, US"tls_crl", &expcrl)) return DEFER; - if (expcrl != NULL && *expcrl != 0) + if (expcrl && *expcrl) { struct stat statbufcrl; if (Ustat(expcrl, &statbufcrl) < 0) @@ -1473,7 +1832,7 @@ DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n", } } - #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ +#endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */ /* If verification is optional, don't fail if no certificate */ @@ -1500,7 +1859,7 @@ Arguments: 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. */ @@ -1510,6 +1869,7 @@ tls_server_start(const uschar *require_ciphers) int rc; uschar *expciphers; tls_ext_ctx_cb *cbinfo; +static uschar peerdn[256]; static uschar cipherbuf[256]; /* Check for previous activation */ @@ -1540,9 +1900,9 @@ were historically separated by underscores. So that I can use either form in my tests, and also for general convenience, we turn underscores into hyphens here. */ -if (expciphers != NULL) +if (expciphers) { - uschar *s = expciphers; + uschar * s = expciphers; while (*s != 0) { if (*s == '_') *s = '-'; s++; } DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers); if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers)) @@ -1576,7 +1936,7 @@ else if (verify_check_host(&tls_try_verify_hosts) == OK) /* Prepare for new connection */ -if ((server_ssl = SSL_new(server_ctx)) == NULL) return tls_error(US"SSL_new", NULL, NULL); +if (!(server_ssl = SSL_new(server_ctx))) return tls_error(US"SSL_new", NULL, NULL); /* Warning: we used to SSL_clear(ssl) here, it was removed. * @@ -1632,6 +1992,8 @@ DEBUG(D_tls) debug_printf("SSL_accept was successful\n"); /* TLS has been set up. Adjust the input functions to read via TLS, and initialize things. */ +peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn)); + construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits); tls_in.cipher = cipherbuf; @@ -1658,6 +2020,7 @@ ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0; ssl_xfer_eof = ssl_xfer_error = 0; receive_getc = tls_getc; +receive_get_cache = tls_get_cache; receive_ungetc = tls_ungetc; receive_feof = tls_feof; receive_ferror = tls_ferror; @@ -1672,18 +2035,17 @@ return OK; static int tls_client_basic_ctx_init(SSL_CTX * ctx, - host_item * host, smtp_transport_options_block * ob -#ifdef EXPERIMENTAL_CERTNAMES - , tls_ext_ctx_cb * cbinfo -#endif + host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo ) { int rc; -/* stick to the old behaviour for compatibility if tls_verify_certificates is +/* stick to the old behaviour for compatibility if tls_verify_certificates is set but both tls_verify_hosts and tls_try_verify_hosts is not set. Check only the specified host patterns if one of them is defined */ -if ( (!ob->tls_verify_hosts && !ob->tls_try_verify_hosts) +if ( ( !ob->tls_verify_hosts + && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts) + ) || (verify_check_given_host(&ob->tls_verify_hosts, host) == OK) ) client_verify_optional = FALSE; @@ -1696,14 +2058,17 @@ if ((rc = setup_certs(ctx, ob->tls_verify_certificates, ob->tls_crl, host, client_verify_optional, verify_callback_client)) != OK) return rc; -#ifdef EXPERIMENTAL_CERTNAMES if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK) { - cbinfo->verify_cert_hostnames = host->name; + cbinfo->verify_cert_hostnames = +#ifdef SUPPORT_I18N + string_domain_utf8_to_alabel(host->name, NULL); +#else + host->name; +#endif DEBUG(D_tls) debug_printf("Cert hostname to check: \"%s\"\n", cbinfo->verify_cert_hostnames); } -#endif return OK; } @@ -1725,7 +2090,7 @@ for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr = dns_next_rr(dnsa, &dnss, RESET_NEXT) ) if (rr->type == T_TLSA) { - uschar * p = rr->data; + const uschar * p = rr->data; uint8_t usage, selector, mtype; const char * mdname; @@ -1749,8 +2114,8 @@ for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3)) { default: - case 0: /* action not taken */ return tls_error(US"tlsa load", host, NULL); + case 0: /* action not taken */ case 1: break; } @@ -1761,7 +2126,7 @@ if (found) return OK; log_write(0, LOG_MAIN, "DANE error: No usable TLSA records"); -return FAIL; +return DEFER; } #endif /*EXPERIMENTAL_DANE*/ @@ -1795,9 +2160,8 @@ tls_client_start(int fd, host_item *host, address_item *addr, { smtp_transport_options_block * ob = (smtp_transport_options_block *)tb->options_block; -static uschar txt[256]; +static uschar peerdn[256]; uschar * expciphers; -X509 * server_cert; int rc; static uschar cipherbuf[256]; @@ -1882,11 +2246,8 @@ else #endif - if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob -#ifdef EXPERIMENTAL_CERTNAMES - , client_static_cbinfo -#endif - )) != OK) + if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob, client_static_cbinfo)) + != OK) return rc; if ((client_ssl = SSL_new(client_ctx)) == NULL) @@ -1911,8 +2272,7 @@ if (ob->tls_sni) DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni); SSL_set_tlsext_host_name(client_ssl, tls_out.sni); #else - DEBUG(D_tls) - debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n", + log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n", tls_out.sni); #endif } @@ -1952,7 +2312,7 @@ if (request_ocsp) } #endif -#ifdef EXPERIMENTAL_EVENT +#ifndef DISABLE_EVENT client_static_cbinfo->event_action = tb->event_action; #endif @@ -1974,17 +2334,7 @@ if (rc <= 0) DEBUG(D_tls) debug_printf("SSL_connect succeeded\n"); -/* Beware anonymous ciphers which lead to server_cert being NULL */ -/*XXX server_cert is never freed... use X509_free() */ -server_cert = SSL_get_peer_certificate (client_ssl); -if (server_cert) - { - tls_out.peerdn = US X509_NAME_oneline(X509_get_subject_name(server_cert), - CS txt, sizeof(txt)); - tls_out.peerdn = txt; /*XXX a static buffer... */ - } -else - tls_out.peerdn = NULL; +peer_cert(client_ssl, &tls_out, peerdn, sizeof(peerdn)); construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits); tls_out.cipher = cipherbuf; @@ -2010,14 +2360,14 @@ return OK; /* This gets the next byte from the TLS input buffer. If the buffer is empty, it refills the buffer via the SSL reading function. -Arguments: none +Arguments: lim Maximum amount to read/buffer Returns: the next character or EOF Only used by the server-side TLS. */ int -tls_getc(void) +tls_getc(unsigned lim) { if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) { @@ -2028,7 +2378,8 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) ssl_xfer_buffer, ssl_xfer_buffer_size); if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout); - inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size); + inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, + MIN(ssl_xfer_buffer_size, lim)); error = SSL_get_error(server_ssl, inbytes); alarm(0); @@ -2041,6 +2392,7 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n"); receive_getc = smtp_getc; + receive_get_cache = smtp_get_cache; receive_ungetc = smtp_ungetc; receive_feof = smtp_feof; receive_ferror = smtp_ferror; @@ -2054,7 +2406,7 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) tls_in.peerdn = NULL; tls_in.sni = NULL; - return smtp_getc(); + return smtp_getc(lim); } /* Handle genuine errors */ @@ -2086,6 +2438,16 @@ if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm) return ssl_xfer_buffer[ssl_xfer_buffer_lwm++]; } +void +tls_get_cache() +{ +#ifndef DISABLE_DKIM +int n = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm; +if (n > 0) + dkim_exim_verify_feed(ssl_xfer_buffer+ssl_xfer_buffer_lwm, n); +#endif +} + /************************************************* @@ -2167,27 +2529,28 @@ while (left > 0) switch (error) { case SSL_ERROR_SSL: - ERR_error_string(ERR_get_error(), ssl_errstring); - log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); - return -1; + ERR_error_string(ERR_get_error(), ssl_errstring); + log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring); + return -1; case SSL_ERROR_NONE: - left -= outbytes; - buff += outbytes; - break; + left -= outbytes; + buff += outbytes; + break; case SSL_ERROR_ZERO_RETURN: - log_write(0, LOG_MAIN, "SSL channel closed on write"); - return -1; + log_write(0, LOG_MAIN, "SSL channel closed on write"); + return -1; case SSL_ERROR_SYSCALL: - log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", - sender_fullhost ? sender_fullhost : US"", - strerror(errno)); + log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s", + sender_fullhost ? sender_fullhost : US"", + strerror(errno)); + return -1; default: - log_write(0, LOG_MAIN, "SSL_write error %d", error); - return -1; + log_write(0, LOG_MAIN, "SSL_write error %d", error); + return -1; } } return len; @@ -2398,8 +2761,13 @@ i = (i + 7) / 8; if (i < needed_len) needed_len = i; +#ifdef EXIM_HAVE_RAND_PSEUDO /* We do not care if crypto-strong */ i = RAND_pseudo_bytes(smallbuf, needed_len); +#else +i = RAND_bytes(smallbuf, needed_len); +#endif + if (i < 0) { DEBUG(D_all) @@ -2593,6 +2961,9 @@ result = 0L; #ifdef SSL_OP_NO_SSLv2 result |= SSL_OP_NO_SSLv2; #endif +#ifdef SSL_OP_SINGLE_DH_USE +result |= SSL_OP_SINGLE_DH_USE; +#endif if (option_spec == NULL) { @@ -2616,6 +2987,7 @@ for (s=option_spec; *s != '\0'; /**/) keep_c = *end; *end = '\0'; item_parsed = tls_openssl_one_option_parse(s, &item); + *end = keep_c; if (!item_parsed) { DEBUG(D_tls) debug_printf("openssl option setting unrecognised: \"%s\"\n", s); @@ -2627,7 +2999,6 @@ for (s=option_spec; *s != '\0'; /**/) result |= item; else result &= ~item; - *end = keep_c; s = end; }