* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2012 */
+/* Copyright (c) University of Cambridge 1995 - 2015 */
/* See the file NOTICE for conditions of use and distribution. */
+/* Portions Copyright (c) The OpenSSL Project 1999 */
+
/* This module provides the TLS (aka SSL) support for Exim using the OpenSSL
library. It is #included into the tls.c file when that library is used. The
code herein is based on a patch that was originally contributed by Steve
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
-#ifdef EXPERIMENTAL_OCSP
-#include <openssl/ocsp.h>
+#ifndef OPENSSL_NO_ECDH
+# include <openssl/ec.h>
+#endif
+#ifndef DISABLE_OCSP
+# include <openssl/ocsp.h>
+#endif
+#ifdef EXPERIMENTAL_DANE
+# include <danessl.h>
#endif
-#ifdef EXPERIMENTAL_OCSP
-#define EXIM_OCSP_SKEW_SECONDS (300L)
-#define EXIM_OCSP_MAX_AGE (-1L)
+
+#ifndef DISABLE_OCSP
+# define EXIM_OCSP_SKEW_SECONDS (300L)
+# define EXIM_OCSP_MAX_AGE (-1L)
#endif
#if OPENSSL_VERSION_NUMBER >= 0x0090806fL && !defined(OPENSSL_NO_TLSEXT)
-#define EXIM_HAVE_OPENSSL_TLSEXT
+# define EXIM_HAVE_OPENSSL_TLSEXT
+#endif
+
+/*
+ * 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
+# endif
+
+# if !defined(OPENSSL_NO_ECDH)
+# if OPENSSL_VERSION_NUMBER >= 0x0090800fL
+# define EXIM_HAVE_ECDH
+# endif
+# if OPENSSL_VERSION_NUMBER >= 0x10002000L
+# define EXIM_HAVE_OPENSSL_ECDH_AUTO
+# define EXIM_HAVE_OPENSSL_EC_NIST2NID
+# endif
+# endif
+#endif
+
+#if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP)
+# warning "OpenSSL library version too old; define DISABLE_OCSP in Makefile"
+# define DISABLE_OCSP
#endif
/* Structure for collecting random data for seeding. */
static BOOL client_verify_optional = FALSE;
static BOOL server_verify_optional = FALSE;
-static BOOL reexpand_tls_files_for_sni = FALSE;
+static BOOL reexpand_tls_files_for_sni = FALSE;
typedef struct tls_ext_ctx_cb {
uschar *certificate;
uschar *privatekey;
-#ifdef EXPERIMENTAL_OCSP
- uschar *ocsp_file;
- uschar *ocsp_file_expanded;
- OCSP_RESPONSE *ocsp_response;
+#ifndef DISABLE_OCSP
+ BOOL is_server;
+ union {
+ struct {
+ uschar *file;
+ uschar *file_expanded;
+ OCSP_RESPONSE *response;
+ } server;
+ struct {
+ X509_STORE *verify_store; /* non-null if status requested */
+ BOOL verify_required;
+ } client;
+ } u_ocsp;
#endif
uschar *dhparam;
/* these are cached from first expand */
uschar *server_cipher_list;
/* only passed down to tls_error: */
host_item *host;
+ const uschar * verify_cert_hostnames;
+#ifndef DISABLE_EVENT
+ uschar * event_action;
+#endif
} tls_ext_ctx_cb;
/* should figure out a cleanup of API to handle state preserved per
tls_ext_ctx_cb *server_static_cbinfo = NULL;
static int
-setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, BOOL client);
+setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
+ int (*cert_vfy_cb)(int, X509_STORE_CTX *) );
/* Callbacks */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
static int tls_servername_cb(SSL *s, int *ad ARG_UNUSED, void *arg);
#endif
-#ifdef EXPERIMENTAL_OCSP
-static int tls_stapling_cb(SSL *s, void *arg);
+#ifndef DISABLE_OCSP
+static int tls_server_stapling_cb(SSL *s, void *arg);
#endif
*/
static int
-tls_error(uschar *prefix, host_item *host, uschar *msg)
+tls_error(uschar * prefix, const host_item * host, uschar * msg)
{
-if (msg == NULL)
+if (!msg)
{
ERR_error_string(ERR_get_error(), ssl_errstring);
msg = (uschar *)ssl_errstring;
}
-if (host == NULL)
+if (host)
+ {
+ log_write(0, LOG_MAIN, "H=%s [%s] TLS error on connection (%s): %s",
+ host->name, host->address, prefix, 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",
conn_info, prefix, msg);
return DEFER;
}
-else
- {
- log_write(0, LOG_MAIN, "TLS error on connection to %s [%s] (%s): %s",
- host->name, host->address, prefix, msg);
- return FAIL;
- }
}
+/* Extreme debug
+#ifndef DISABLE_OCSP
+void
+x509_store_dump_cert_s_names(X509_STORE * store)
+{
+STACK_OF(X509_OBJECT) * roots= store->objs;
+int i;
+static uschar name[256];
+
+for(i= 0; i<sk_X509_OBJECT_num(roots); i++)
+ {
+ X509_OBJECT * tmp_obj= sk_X509_OBJECT_value(roots, i);
+ if(tmp_obj->type == X509_LU_X509)
+ {
+ X509 * current_cert= tmp_obj->data.x509;
+ X509_NAME_oneline(X509_get_subject_name(current_cert), CS name, sizeof(name));
+ name[sizeof(name)-1] = '\0';
+ debug_printf(" %s\n", name);
+ }
+ }
+}
+#endif
+*/
+
+
+#ifndef DISABLE_EVENT
+static int
+verify_event(tls_support * tlsp, X509 * cert, int depth, const uschar * dn,
+ BOOL *calledp, const BOOL *optionalp, const uschar * what)
+{
+uschar * ev;
+uschar * yield;
+X509 * old_cert;
+
+ev = tlsp == &tls_out ? client_static_cbinfo->event_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
optional verification for this case is done when requesting SSL to verify, by
setting SSL_VERIFY_FAIL_IF_NO_PEER_CERT in the non-optional case.
+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.
*/
static int
-verify_callback(int state, X509_STORE_CTX *x509ctx, BOOL client)
+verify_callback(int state, X509_STORE_CTX *x509ctx,
+ tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
{
-static uschar txt[256];
-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);
+uschar dn[256];
-if (client)
- {
- tlsp= &tls_out;
- calledp= &client_verify_callback_called;
- optionalp= &client_verify_optional;
- }
-else
- {
- tlsp= &tls_in;
- calledp= &server_verify_callback_called;
- optionalp= &server_verify_optional;
- }
-
-X509_NAME_oneline(X509_get_subject_name(x509ctx->current_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)
{
- log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s",
- x509ctx->error_depth,
- X509_verify_cert_error_string(x509ctx->error),
- txt);
- tlsp->certificate_verified = FALSE;
+ 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)),
+ dn);
*calledp = TRUE;
- if (!*optionalp) return 0; /* reject */
+ if (!*optionalp)
+ {
+ 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");
- return 1; /* accept */
}
-if (x509ctx->error_depth != 0)
+else if (depth != 0)
{
- DEBUG(D_tls) debug_printf("SSL verify ok: depth=%d cert=%s\n",
- x509ctx->error_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();
+ }
+#endif
+#ifndef DISABLE_EVENT
+ if (verify_event(tlsp, cert, depth, dn, calledp, optionalp, US"SSL"))
+ return 0; /* reject, with peercert set */
+#endif
}
else
{
- DEBUG(D_tls) debug_printf("SSL%s peer: %s\n",
- *calledp ? "" : " authenticated", txt);
- tlsp->peerdn = txt;
- }
+ const uschar * verify_cert_hostnames;
-if (!*calledp) tlsp->certificate_verified = TRUE;
-*calledp = TRUE;
+ if ( tlsp == &tls_out
+ && ((verify_cert_hostnames = client_static_cbinfo->verify_cert_hostnames)))
+ /* client, wanting hostname check */
+ {
-return 1; /* accept */
+#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;
+ 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,
+ X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS
+ | X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS,
+ NULL)))
+ {
+ if (rc < 0)
+ {
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address);
+ name = NULL;
+ }
+ break;
+ }
+ if (!name)
+#else
+ if (!tls_is_name_for_cert(verify_cert_hostnames, cert))
+#endif
+ {
+ log_write(0, LOG_MAIN,
+ "[%s] SSL verify error: certificate name mismatch: \"%s\"",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ dn);
+ *calledp = TRUE;
+ if (!*optionalp)
+ {
+ 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");
+ }
+ }
+
+#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", dn);
+ if (!*calledp) tlsp->certificate_verified = TRUE;
+ *calledp = TRUE;
+ }
+
+return 1; /* accept, at least for this level */
}
static int
verify_callback_client(int state, X509_STORE_CTX *x509ctx)
{
-return verify_callback(state, x509ctx, TRUE);
+return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional);
}
static int
verify_callback_server(int state, X509_STORE_CTX *x509ctx)
{
-return verify_callback(state, x509ctx, FALSE);
+return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional);
+}
+
+
+#ifdef EXPERIMENTAL_DANE
+
+/* This gets called *by* the dane library verify callback, which interposes
+itself.
+*/
+static int
+verify_callback_client_dane(int state, X509_STORE_CTX * x509ctx)
+{
+X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
+uschar dn[256];
+#ifndef DISABLE_EVENT
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+BOOL dummy_called, optional = FALSE;
+#endif
+
+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", dn);
+
+#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)
+ tls_out.dane_verified =
+ tls_out.certificate_verified = TRUE;
+return 1;
}
+#endif /*EXPERIMENTAL_DANE*/
/*************************************************
/* 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
*/
static BOOL
-init_dh(SSL_CTX *sctx, uschar *dhparam, host_item *host)
+init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host)
{
BIO *bio;
DH *dh;
if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded))
return FALSE;
-if (dhexpanded == NULL || *dhexpanded == '\0')
- {
+if (!dhexpanded || !*dhexpanded)
bio = BIO_new_mem_buf(CS std_dh_prime_default(), -1);
- }
else if (dhexpanded[0] == '/')
{
- bio = BIO_new_file(CS dhexpanded, "r");
- if (bio == NULL)
+ if (!(bio = BIO_new_file(CS dhexpanded, "r")))
{
tls_error(string_sprintf("could not read dhparams file %s", dhexpanded),
host, US strerror(errno));
return TRUE;
}
- pem = std_dh_prime_named(dhexpanded);
- if (!pem)
+ if (!(pem = std_dh_prime_named(dhexpanded)))
{
tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded),
host, US strerror(errno));
bio = BIO_new_mem_buf(CS pem, -1);
}
-dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL);
-if (dh == NULL)
+if (!(dh = PEM_read_bio_DHparams(bio, NULL, NULL, NULL)))
{
BIO_free(bio);
tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded),
-#ifdef EXPERIMENTAL_OCSP
+/*************************************************
+* 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;
+
+# ifdef EXIM_HAVE_OPENSSL_ECDH_AUTO
+/* check if new enough library to support auto ECDH temp key parameter selection */
+if (Ustrcmp(exp_curve, "auto") == 0)
+ {
+ DEBUG(D_tls) debug_printf(
+ "ECDH temp key parameter settings: OpenSSL 1.2+ autoselection\n");
+ SSL_CTX_set_ecdh_auto(sctx, 1);
+ return TRUE;
+ }
+# 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 OCSP response from the given file into memory, once
+/* 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.
*/
static void
-ocsp_load_response(SSL_CTX *sctx,
- tls_ext_ctx_cb *cbinfo,
- const uschar *expanded)
+ocsp_load_response(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo, const uschar *expanded)
{
BIO *bio;
OCSP_RESPONSE *resp;
unsigned long verify_flags;
int status, reason, i;
-cbinfo->ocsp_file_expanded = string_copy(expanded);
-if (cbinfo->ocsp_response)
+cbinfo->u_ocsp.server.file_expanded = string_copy(expanded);
+if (cbinfo->u_ocsp.server.response)
{
- OCSP_RESPONSE_free(cbinfo->ocsp_response);
- cbinfo->ocsp_response = NULL;
+ OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response);
+ cbinfo->u_ocsp.server.response = NULL;
}
-bio = BIO_new_file(CS cbinfo->ocsp_file_expanded, "rb");
+bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb");
if (!bio)
{
DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n",
- cbinfo->ocsp_file_expanded);
+ cbinfo->u_ocsp.server.file_expanded);
return;
}
{
DEBUG(D_tls) debug_printf("OCSP response not valid: %s (%d)\n",
OCSP_response_status_str(status), status);
- return;
+ goto bad;
}
basic_response = OCSP_response_get1_basic(resp);
{
DEBUG(D_tls)
debug_printf("OCSP response parse error: unable to extract basic response.\n");
- return;
+ goto bad;
}
store = SSL_CTX_get_cert_store(sctx);
DEBUG(D_tls) {
ERR_error_string(ERR_get_error(), ssl_errstring);
debug_printf("OCSP response verify failure: %s\n", US ssl_errstring);
- }
- return;
+ }
+ goto bad;
}
/* Here's the simplifying assumption: there's only one response, for the
{
DEBUG(D_tls)
debug_printf("Unable to get first response from OCSP basic response.\n");
- return;
+ goto bad;
}
status = OCSP_single_get0_status(single_response, &reason, &rev, &thisupd, &nextupd);
-/* how does this status differ from the one above? */
-if (status != OCSP_RESPONSE_STATUS_SUCCESSFUL)
+if (status != V_OCSP_CERTSTATUS_GOOD)
{
- DEBUG(D_tls) debug_printf("OCSP response not valid (take 2): %s (%d)\n",
- OCSP_response_status_str(status), status);
- return;
+ DEBUG(D_tls) debug_printf("OCSP response bad cert status: %s (%d) %s (%d)\n",
+ OCSP_cert_status_str(status), status,
+ OCSP_crl_reason_str(reason), reason);
+ goto bad;
}
if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
{
DEBUG(D_tls) debug_printf("OCSP status invalid times.\n");
- return;
+ goto bad;
}
-cbinfo->ocsp_response = resp;
+supply_response:
+ cbinfo->u_ocsp.server.response = resp;
+return;
+
+bad:
+ if (running_in_test_harness)
+ {
+ extern char ** environ;
+ uschar ** p;
+ 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");
+ goto supply_response;
+ }
+ }
+return;
}
-#endif
+#endif /*!DISABLE_OCSP*/
* Expand key and cert file specs *
*************************************************/
-/* Called once during tls_init and possibly againt during TLS setup, for a
+/* Called once during tls_init and possibly again during TLS setup, for a
new context, if Server Name Indication was used and tls_sni was seen in
the certificate string.
"SSL_CTX_use_PrivateKey_file file=%s", expanded), cbinfo->host, NULL);
}
-#ifdef EXPERIMENTAL_OCSP
-if (cbinfo->ocsp_file != NULL)
+#ifndef DISABLE_OCSP
+if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL)
{
- if (!expand_check(cbinfo->ocsp_file, US"tls_ocsp_file", &expanded))
+ if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded))
return DEFER;
if (expanded != NULL && *expanded != 0)
{
DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded);
- if (cbinfo->ocsp_file_expanded &&
- (Ustrcmp(expanded, cbinfo->ocsp_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");
not confident that memcpy wouldn't break some internal reference counting.
Especially since there's a references struct member, which would be off. */
-server_sni = SSL_CTX_new(SSLv23_server_method());
-if (!server_sni)
+if (!(server_sni = SSL_CTX_new(SSLv23_server_method())))
{
ERR_error_string(ERR_get_error(), ssl_errstring);
DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring);
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);
-#ifdef EXPERIMENTAL_OCSP
-if (cbinfo->ocsp_file)
+#ifndef DISABLE_OCSP
+if (cbinfo->u_ocsp.server.file)
{
- SSL_CTX_set_tlsext_status_cb(server_sni, tls_stapling_cb);
+ SSL_CTX_set_tlsext_status_cb(server_sni, tls_server_stapling_cb);
SSL_CTX_set_tlsext_status_arg(server_sni, cbinfo);
}
#endif
-rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, FALSE);
+rc = setup_certs(server_sni, tls_verify_certificates, tls_crl, NULL, FALSE, verify_callback_server);
if (rc != 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;
-
-rc = init_dh(server_sni, cbinfo->dhparam, NULL);
-if (rc != OK) return SSL_TLSEXT_ERR_NOACK;
+if ((rc = tls_expand_session_files(server_sni, cbinfo)) != OK)
+ return SSL_TLSEXT_ERR_NOACK;
DEBUG(D_tls) debug_printf("Switching SSL context.\n");
SSL_set_SSL_CTX(s, server_sni);
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
+
/*************************************************
* Callback to handle OCSP Stapling *
*************************************************/
*/
static int
-tls_stapling_cb(SSL *s, void *arg)
+tls_server_stapling_cb(SSL *s, void *arg)
{
const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
uschar *response_der;
int response_der_len;
-DEBUG(D_tls) debug_printf("Received TLS status request (OCSP stapling); %s response.\n",
- cbinfo->ocsp_response ? "have" : "lack");
-if (!cbinfo->ocsp_response)
+DEBUG(D_tls)
+ debug_printf("Received TLS status request (OCSP stapling); %s response\n",
+ cbinfo->u_ocsp.server.response ? "have" : "lack");
+
+tls_in.ocsp = OCSP_NOT_RESP;
+if (!cbinfo->u_ocsp.server.response)
return SSL_TLSEXT_ERR_NOACK;
response_der = NULL;
-response_der_len = i2d_OCSP_RESPONSE(cbinfo->ocsp_response, &response_der);
+response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response,
+ &response_der);
if (response_der_len <= 0)
return SSL_TLSEXT_ERR_NOACK;
SSL_set_tlsext_status_ocsp_resp(server_ssl, response_der, response_der_len);
+tls_in.ocsp = OCSP_VFIED;
return SSL_TLSEXT_ERR_OK;
}
-#endif /* EXPERIMENTAL_OCSP */
+static void
+time_print(BIO * bp, const char * str, ASN1_GENERALIZEDTIME * time)
+{
+BIO_printf(bp, "\t%s: ", str);
+ASN1_GENERALIZEDTIME_print(bp, time);
+BIO_puts(bp, "\n");
+}
+static int
+tls_client_stapling_cb(SSL *s, void *arg)
+{
+tls_ext_ctx_cb * cbinfo = arg;
+const unsigned char * p;
+int len;
+OCSP_RESPONSE * rsp;
+OCSP_BASICRESP * bs;
+int i;
+
+DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):");
+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 && LOGGING(tls_cipher))
+ log_write(0, LOG_MAIN, "Received TLS status callback, null content");
+ else
+ DEBUG(D_tls) debug_printf(" null\n");
+ return cbinfo->u_ocsp.client.verify_required ? 0 : 1;
+ }
+
+if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
+ {
+ tls_out.ocsp = OCSP_FAILED;
+ 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");
+ return 0;
+ }
+
+if(!(bs = OCSP_response_get1_basic(rsp)))
+ {
+ tls_out.ocsp = OCSP_FAILED;
+ 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");
+ OCSP_RESPONSE_free(rsp);
+ return 0;
+ }
+
+/* We'd check the nonce here if we'd put one in the request. */
+/* However that would defeat cacheability on the server so we don't. */
+
+/* This section of code reworked from OpenSSL apps source;
+ The OpenSSL Project retains copyright:
+ Copyright (c) 1999 The OpenSSL Project. All rights reserved.
+*/
+ {
+ BIO * bp = NULL;
+ int status, reason;
+ ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
+
+ DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE);
+
+ /*OCSP_RESPONSE_print(bp, rsp, 0); extreme debug: stapling content */
+
+ /* 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,
+ cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
+ {
+ tls_out.ocsp = OCSP_FAILED;
+ 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;
+ }
+
+ BIO_printf(bp, "OCSP response well-formed and signed OK\n");
+
+ {
+ STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
+ OCSP_SINGLERESP * single;
+
+ if (sk_OCSP_SINGLERESP_num(sresp) != 1)
+ {
+ 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;
+ }
+ single = OCSP_resp_get0(bs, 0);
+ status = OCSP_single_get0_status(single, &reason, &rev,
+ &thisupd, &nextupd);
+ }
+
+ DEBUG(D_tls) time_print(bp, "This OCSP Update", thisupd);
+ DEBUG(D_tls) if(nextupd) time_print(bp, "Next OCSP Update", nextupd);
+ if (!OCSP_check_validity(thisupd, nextupd,
+ EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX_AGE))
+ {
+ 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
+ {
+ DEBUG(D_tls) BIO_printf(bp, "Certificate status: %s\n",
+ OCSP_cert_status_str(status));
+ switch(status)
+ {
+ case V_OCSP_CERTSTATUS_GOOD:
+ tls_out.ocsp = OCSP_VFIED;
+ i = 1;
+ break;
+ 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:
+ BIO_free(bp);
+ }
+
+OCSP_RESPONSE_free(rsp);
+return i;
+}
+#endif /*!DISABLE_OCSP*/
/*************************************************
* Initialize for TLS *
*************************************************/
-/* Called from both server and client code, to do preliminary initialization of
-the library.
+/* Called from both server and client code, to do preliminary initialization
+of the library. We allocate and return a context structure.
Arguments:
+ ctxp returned SSL context
host connected host, if client; NULL if server
dhparam DH parameter file
certificate certificate file
privatekey private key
+ ocsp_file file of stapling info (server); flag for require ocsp (client)
addr address if client; NULL if server (for some randomness)
+ cbp place to put allocated callback context
Returns: OK/DEFER/FAIL
*/
static int
tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate,
uschar *privatekey,
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
uschar *ocsp_file,
#endif
address_item *addr, tls_ext_ctx_cb ** cbp)
long init_options;
int rc;
BOOL okay;
-tls_ext_ctx_cb *cbinfo;
+tls_ext_ctx_cb * cbinfo;
cbinfo = store_malloc(sizeof(tls_ext_ctx_cb));
cbinfo->certificate = certificate;
cbinfo->privatekey = privatekey;
-#ifdef EXPERIMENTAL_OCSP
-cbinfo->ocsp_file = ocsp_file;
-cbinfo->ocsp_file_expanded = NULL;
-cbinfo->ocsp_response = NULL;
+#ifndef DISABLE_OCSP
+if ((cbinfo->is_server = host==NULL))
+ {
+ cbinfo->u_ocsp.server.file = ocsp_file;
+ cbinfo->u_ocsp.server.file_expanded = NULL;
+ cbinfo->u_ocsp.server.response = NULL;
+ }
+else
+ cbinfo->u_ocsp.client.verify_store = NULL;
#endif
cbinfo->dhparam = dhparam;
+cbinfo->server_cipher_list = NULL;
cbinfo->host = host;
+#ifndef DISABLE_EVENT
+cbinfo->event_action = NULL;
+#endif
SSL_load_error_strings(); /* basic set up */
OpenSSL_add_ssl_algorithms();
/* 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);
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) */
/* If we need to handle SNI, do so */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
-if (host == NULL)
+if (host == NULL) /* server */
{
-#ifdef EXPERIMENTAL_OCSP
- /* We check ocsp_file, not ocsp_response, because we care about if
+# ifndef DISABLE_OCSP
+ /* We check u_ocsp.server.file, not server.response, because we care about if
the option exists, not what the current expansion might be, as SNI might
change the certificate and OCSP file in use between now and the time the
callback is invoked. */
- if (cbinfo->ocsp_file)
+ if (cbinfo->u_ocsp.server.file)
{
- SSL_CTX_set_tlsext_status_cb(server_ctx, tls_stapling_cb);
+ SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb);
SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo);
}
-#endif
+# endif
/* We always do this, so that $tls_sni is available even if not used in
tls_certificate */
SSL_CTX_set_tlsext_servername_callback(*ctxp, tls_servername_cb);
SSL_CTX_set_tlsext_servername_arg(*ctxp, cbinfo);
}
+# ifndef DISABLE_OCSP
+else /* client */
+ if(ocsp_file) /* wanting stapling */
+ {
+ if (!(cbinfo->u_ocsp.client.verify_store = X509_STORE_new()))
+ {
+ DEBUG(D_tls) debug_printf("failed to create store for stapling verify\n");
+ return FAIL;
+ }
+ SSL_CTX_set_tlsext_status_cb(*ctxp, tls_client_stapling_cb);
+ SSL_CTX_set_tlsext_status_arg(*ctxp, cbinfo);
+ }
+# endif
#endif
+cbinfo->verify_cert_hostnames = NULL;
+
/* Set up the RSA callback */
SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback);
yet reflect that. It should be a safe change anyway, even 0.9.8 versions have
the accessor functions use const in the prototype. */
const SSL_CIPHER *c;
-uschar *ver;
-
-switch (ssl->session->ssl_version)
- {
- case SSL2_VERSION:
- ver = US"SSLv2";
- break;
-
- case SSL3_VERSION:
- ver = US"SSLv3";
- break;
+const uschar *ver;
- case TLS1_VERSION:
- ver = US"TLSv1";
- break;
-
-#ifdef TLS1_1_VERSION
- case TLS1_1_VERSION:
- ver = US"TLSv1.1";
- break;
-#endif
-
-#ifdef TLS1_2_VERSION
- case TLS1_2_VERSION:
- ver = US"TLSv1.2";
- break;
-#endif
-
- default:
- ver = US"UNKNOWN";
- }
+ver = (const uschar *)SSL_get_version(ssl);
c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl);
SSL_CIPHER_get_bits(c, bits);
}
+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;
+}
+
+
host NULL in a server; the remote host in a client
optional TRUE if called from a server for a host in tls_try_verify_hosts;
otherwise passed as FALSE
- client TRUE if called for client startup, FALSE for server startup
+ cert_vfy_cb Callback function for certificate verification
Returns: OK/DEFER/FAIL
*/
static int
-setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional, BOOL client)
+setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
+ int (*cert_vfy_cb)(int, X509_STORE_CTX *) )
{
uschar *expcerts, *expcrl;
if (expcerts != NULL && *expcerts != '\0')
{
- struct stat statbuf;
- 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;
+ /* Tell the library to use its compiled-in location for the system default
+ CA bundle, only */
+
+ if (!SSL_CTX_set_default_verify_paths(sctx))
+ return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL);
}
else
{
- uschar *file, *dir;
- if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
- { file = NULL; dir = expcerts; }
- else
- { file = expcerts; dir = NULL; }
+ struct stat statbuf;
- /* 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. */
+ /* Tell the library to use its compiled-in location for the system default
+ CA bundle. Those given by the exim config are additional to these */
- 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);
+ if (!SSL_CTX_set_default_verify_paths(sctx))
+ return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL);
- if (file != NULL)
+ if (Ustat(expcerts, &statbuf) < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "failed to stat %s for certificates", expcerts);
+ return DEFER;
+ }
+ else
{
- SSL_CTX_set_client_CA_list(sctx, SSL_load_client_CA_file(CS file));
+ uschar *file, *dir;
+ if ((statbuf.st_mode & S_IFMT) == S_IFDIR)
+ { file = NULL; dir = expcerts; }
+ 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);
+ }
}
}
SSL_CTX_set_verify(sctx,
SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT),
- client ? verify_callback_client : verify_callback_server);
+ cert_vfy_cb);
}
return OK;
int rc;
uschar *expciphers;
tls_ext_ctx_cb *cbinfo;
+static uschar peerdn[256];
static uschar cipherbuf[256];
/* Check for previous activation */
the error. */
rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey,
-#ifdef EXPERIMENTAL_OCSP
+#ifndef DISABLE_OCSP
tls_ocsp_file,
#endif
NULL, &server_static_cbinfo);
optional, set up appropriately. */
tls_in.certificate_verified = FALSE;
+#ifdef EXPERIMENTAL_DANE
+tls_in.dane_verified = FALSE;
+#endif
server_verify_callback_called = FALSE;
if (verify_check_host(&tls_verify_hosts) == OK)
{
- rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, FALSE, FALSE);
+ rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
+ FALSE, verify_callback_server);
if (rc != OK) return rc;
server_verify_optional = FALSE;
}
else if (verify_check_host(&tls_try_verify_hosts) == OK)
{
- rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL, TRUE, FALSE);
+ rc = setup_certs(server_ctx, tls_verify_certificates, tls_crl, NULL,
+ TRUE, verify_callback_server);
if (rc != OK) return rc;
server_verify_optional = TRUE;
}
/* 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;
debug_printf("Shared ciphers: %s\n", buf);
}
+/* Record the certificate we presented */
+ {
+ X509 * crt = SSL_get_certificate(server_ssl);
+ tls_in.ourcert = crt ? X509_dup(crt) : NULL;
+ }
/* Only used by the server-side tls (tls_in), including tls_getc.
Client-side (tls_out) reads (seem to?) go via
+static int
+tls_client_basic_ctx_init(SSL_CTX * ctx,
+ 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
+ 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 || !*ob->tls_try_verify_hosts)
+ )
+ || (verify_check_given_host(&ob->tls_verify_hosts, host) == OK)
+ )
+ client_verify_optional = FALSE;
+else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK)
+ client_verify_optional = TRUE;
+else
+ return OK;
+
+if ((rc = setup_certs(ctx, ob->tls_verify_certificates,
+ ob->tls_crl, host, client_verify_optional, verify_callback_client)) != OK)
+ return rc;
+
+if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK)
+ {
+ 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);
+ }
+return OK;
+}
+
+
+#ifdef EXPERIMENTAL_DANE
+static int
+dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa)
+{
+dns_record * rr;
+dns_scan dnss;
+const char * hostnames[2] = { CS host->name, NULL };
+int found = 0;
+
+if (DANESSL_init(ssl, NULL, hostnames) != 1)
+ return tls_error(US"hostnames load", host, NULL);
+
+for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
+ rr;
+ rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
+ ) if (rr->type == T_TLSA)
+ {
+ uschar * p = rr->data;
+ uint8_t usage, selector, mtype;
+ const char * mdname;
+
+ usage = *p++;
+
+ /* Only DANE-TA(2) and DANE-EE(3) are supported */
+ if (usage != 2 && usage != 3) continue;
+
+ selector = *p++;
+ mtype = *p++;
+
+ switch (mtype)
+ {
+ default: continue; /* Only match-types 0, 1, 2 are supported */
+ case 0: mdname = NULL; break;
+ case 1: mdname = "sha256"; break;
+ case 2: mdname = "sha512"; break;
+ }
+
+ found++;
+ 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 1: break;
+ }
+
+ tls_out.tlsa_usage |= 1<<usage;
+ }
+
+if (found)
+ return OK;
+
+log_write(0, LOG_MAIN, "DANE error: No usable TLSA records");
+return DEFER;
+}
+#endif /*EXPERIMENTAL_DANE*/
+
+
/*************************************************
* Start a TLS session in a client *
fd the fd of the connection
host connected host (for messages)
addr the first address
- dhparam DH parameter file
- certificate certificate file
- privatekey private key file
- sni TLS SNI to send to remote host
- verify_certs file for certificate verify
- crl file containing CRL
- require_ciphers list of allowed ciphers
- dh_min_bits minimum number of bits acceptable in server's DH prime
- (unused in OpenSSL)
- timeout startup timeout
+ tb transport (always smtp)
+ tlsa_dnsa tlsa lookup, if DANE, else null
Returns: OK on success
FAIL otherwise - note that tls_error() will not give DEFER
*/
int
-tls_client_start(int fd, host_item *host, address_item *addr, uschar *dhparam,
- uschar *certificate, uschar *privatekey, uschar *sni,
- uschar *verify_certs, uschar *crl,
- uschar *require_ciphers, int dh_min_bits ARG_UNUSED, int timeout)
+tls_client_start(int fd, host_item *host, address_item *addr,
+ transport_instance *tb
+#ifdef EXPERIMENTAL_DANE
+ , dns_answer * tlsa_dnsa
+#endif
+ )
{
-static uschar txt[256];
-uschar *expciphers;
-X509* server_cert;
+smtp_transport_options_block * ob =
+ (smtp_transport_options_block *)tb->options_block;
+static uschar peerdn[256];
+uschar * expciphers;
int rc;
static uschar cipherbuf[256];
-rc = tls_init(&client_ctx, host, dhparam, certificate, privatekey,
-#ifdef EXPERIMENTAL_OCSP
- NULL,
+#ifndef DISABLE_OCSP
+BOOL request_ocsp = FALSE;
+BOOL require_ocsp = FALSE;
+#endif
+
+#ifdef EXPERIMENTAL_DANE
+tls_out.tlsa_usage = 0;
+#endif
+
+#ifndef DISABLE_OCSP
+ {
+# ifdef EXPERIMENTAL_DANE
+ if ( tlsa_dnsa
+ && ob->hosts_request_ocsp[0] == '*'
+ && ob->hosts_request_ocsp[1] == '\0'
+ )
+ {
+ /* Unchanged from default. Use a safer one under DANE */
+ request_ocsp = TRUE;
+ ob->hosts_request_ocsp = US"${if or { {= {0}{$tls_out_tlsa_usage}} "
+ " {= {4}{$tls_out_tlsa_usage}} } "
+ " {*}{}}";
+ }
+# endif
+
+ if ((require_ocsp =
+ verify_check_given_host(&ob->hosts_require_ocsp, host) == OK))
+ request_ocsp = TRUE;
+ else
+# ifdef EXPERIMENTAL_DANE
+ if (!request_ocsp)
+# endif
+ request_ocsp =
+ verify_check_given_host(&ob->hosts_request_ocsp, host) == OK;
+ }
+#endif
+
+rc = tls_init(&client_ctx, host, NULL,
+ ob->tls_certificate, ob->tls_privatekey,
+#ifndef DISABLE_OCSP
+ (void *)(long)request_ocsp,
#endif
addr, &client_static_cbinfo);
if (rc != OK) return rc;
tls_out.certificate_verified = FALSE;
client_verify_callback_called = FALSE;
-if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
+ &expciphers))
return FAIL;
/* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
return tls_error(US"SSL_CTX_set_cipher_list", host, NULL);
}
-rc = setup_certs(client_ctx, verify_certs, crl, host, FALSE, TRUE);
-if (rc != OK) return rc;
+#ifdef EXPERIMENTAL_DANE
+if (tlsa_dnsa)
+ {
+ SSL_CTX_set_verify(client_ctx,
+ SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT,
+ verify_callback_client_dane);
+
+ if (!DANESSL_library_init())
+ return tls_error(US"library init", host, NULL);
+ if (DANESSL_CTX_init(client_ctx) <= 0)
+ return tls_error(US"context init", host, NULL);
+ }
+else
-if ((client_ssl = SSL_new(client_ctx)) == NULL) return tls_error(US"SSL_new", host, NULL);
+#endif
+
+ 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)
+ return tls_error(US"SSL_new", host, NULL);
SSL_set_session_id_context(client_ssl, sid_ctx, Ustrlen(sid_ctx));
SSL_set_fd(client_ssl, fd);
SSL_set_connect_state(client_ssl);
-if (sni)
+if (ob->tls_sni)
{
- if (!expand_check(sni, US"tls_sni", &tls_out.sni))
+ if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni))
return FAIL;
if (tls_out.sni == NULL)
{
}
}
+#ifdef EXPERIMENTAL_DANE
+if (tlsa_dnsa)
+ if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa)) != OK)
+ return rc;
+#endif
+
+#ifndef DISABLE_OCSP
+/* Request certificate status at connection-time. If the server
+does OCSP stapling we will get the callback (set in tls_init()) */
+# ifdef EXPERIMENTAL_DANE
+if (request_ocsp)
+ {
+ const uschar * s;
+ if ( ((s = ob->hosts_require_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage"))
+ || ((s = ob->hosts_request_ocsp) && Ustrstr(s, US"tls_out_tlsa_usage"))
+ )
+ { /* Re-eval now $tls_out_tlsa_usage is populated. If
+ this means we avoid the OCSP request, we wasted the setup
+ cost in tls_init(). */
+ require_ocsp = verify_check_given_host(&ob->hosts_require_ocsp, host) == OK;
+ request_ocsp = require_ocsp
+ || verify_check_given_host(&ob->hosts_request_ocsp, host) == OK;
+ }
+ }
+# endif
+
+if (request_ocsp)
+ {
+ SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp);
+ client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp;
+ tls_out.ocsp = OCSP_NOT_RESP;
+ }
+#endif
+
+#ifndef DISABLE_EVENT
+client_static_cbinfo->event_action = tb->event_action;
+#endif
+
/* There doesn't seem to be a built-in timeout on connection. */
DEBUG(D_tls) debug_printf("Calling SSL_connect\n");
sigalrm_seen = FALSE;
-alarm(timeout);
+alarm(ob->command_timeout);
rc = SSL_connect(client_ssl);
alarm(0);
+#ifdef EXPERIMENTAL_DANE
+if (tlsa_dnsa)
+ DANESSL_cleanup(client_ssl);
+#endif
+
if (rc <= 0)
return tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL);
DEBUG(D_tls) debug_printf("SSL_connect succeeded\n");
-/* Beware anonymous ciphers which lead to server_cert being NULL */
-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;
- }
-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;
+/* Record the certificate we presented */
+ {
+ X509 * crt = SSL_get_certificate(client_ssl);
+ tls_out.ourcert = crt ? X509_dup(crt) : NULL;
+ }
+
tls_out.active = fd;
return OK;
}
it can result in serious failures, including crashing with a SIGSEGV. So
report the version found by the compiler and the run-time version.
+Note: some OS vendors backport security fixes without changing the version
+number/string, and the version date remains unchanged. The _build_ date
+will change, so we can more usefully assist with version diagnosis by also
+reporting the build date.
+
Arguments: a FILE* to print the results to
Returns: nothing
*/
tls_version_report(FILE *f)
{
fprintf(f, "Library version: OpenSSL: Compile: %s\n"
- " Runtime: %s\n",
+ " Runtime: %s\n"
+ " : %s\n",
OPENSSL_VERSION_TEXT,
- SSLeay_version(SSLEAY_VERSION));
+ SSLeay_version(SSLEAY_VERSION),
+ SSLeay_version(SSLEAY_BUILT_ON));
+/* third line is 38 characters for the %s and the line is 73 chars long;
+the OpenSSL output includes a "built on: " prefix already. */
}
{
unsigned int r;
int i, needed_len;
+static pid_t pidlast = 0;
+pid_t pidnow;
uschar *p;
uschar smallbuf[sizeof(r)];
if (max <= 1)
return 0;
+pidnow = getpid();
+if (pidnow != pidlast)
+ {
+ /* Although OpenSSL documents that "OpenSSL makes sure that the PRNG state
+ is unique for each thread", this doesn't apparently apply across processes,
+ so our own warning from vaguely_random_number_fallback() applies here too.
+ Fix per PostgreSQL. */
+ if (pidlast != 0)
+ RAND_cleanup();
+ pidlast = pidnow;
+ }
+
/* OpenSSL auto-seeds from /dev/random, etc, but this a double-check. */
if (!RAND_status())
{
to apply.
This list is current as of:
- ==> 1.0.1b <== */
+ ==> 1.0.1b <==
+Plus SSL_OP_SAFARI_ECDHE_ECDSA_BUG from 2013-June patch/discussion on openssl-dev
+*/
static struct exim_openssl_option exim_openssl_options[] = {
/* KEEP SORTED ALPHABETICALLY! */
#ifdef SSL_OP_ALL
#ifdef SSL_OP_NO_TLSv1_2
{ US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 },
#endif
+#ifdef SSL_OP_SAFARI_ECDHE_ECDSA_BUG
+ { US"safari_ecdhe_ecdsa_bug", SSL_OP_SAFARI_ECDHE_ECDSA_BUG },
+#endif
#ifdef SSL_OP_SINGLE_DH_USE
{ US"single_dh_use", SSL_OP_SINGLE_DH_USE },
#endif
return TRUE;
}
+/* vi: aw ai sw=2
+*/
/* End of tls-openssl.c */
projects / exim.git / blobdiff