* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2014 */
+/* Copyright (c) University of Cambridge 1995 - 2019 */
+/* Copyright (c) The Exim Maintainers 2020 */
/* See the file NOTICE for conditions of use and distribution. */
/* Portions Copyright (c) The OpenSSL Project 1999 */
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/rand.h>
+#ifndef OPENSSL_NO_ECDH
+# include <openssl/ec.h>
+#endif
#ifndef DISABLE_OCSP
# include <openssl/ocsp.h>
#endif
-#ifdef EXPERIMENTAL_DANE
-# include <danessl.h>
+#ifdef SUPPORT_DANE
+# include "danessl.h"
#endif
#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
+# define OPENSSL_AUTO_SHA256
+#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
+# define EXIM_HAVE_OPENSSL_DH_BITS
+# define EXIM_HAVE_OPENSSL_TLS_METHOD
+# define EXIM_HAVE_OPENSSL_KEYLOG
+# define EXIM_HAVE_OPENSSL_CIPHER_GET_ID
+# define EXIM_HAVE_SESSION_TICKET
+# define EXIM_HAVE_OPESSL_TRACE
+# define EXIM_HAVE_OPESSL_GET0_SERIAL
+# ifndef DISABLE_OCSP
+# define EXIM_HAVE_OCSP
+# endif
+# else
+# define EXIM_NEED_OPENSSL_INIT
+# 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
+
+#ifndef LIBRESSL_VERSION_NUMBER
+# if OPENSSL_VERSION_NUMBER >= 0x010101000L
+# define OPENSSL_HAVE_KEYLOG_CB
+# define OPENSSL_HAVE_NUM_TICKETS
+# define EXIM_HAVE_OPENSSL_CIPHER_STD_NAME
+# else
+# define OPENSSL_BAD_SRVR_OURCERT
+# endif
#endif
#if !defined(EXIM_HAVE_OPENSSL_TLSEXT) && !defined(DISABLE_OCSP)
# define DISABLE_OCSP
#endif
+#ifdef EXPERIMENTAL_TLS_RESUME
+# if OPENSSL_VERSION_NUMBER < 0x0101010L
+# error OpenSSL version too old for session-resumption
+# endif
+#endif
+
+#ifdef EXIM_HAVE_OPENSSL_CHECKHOST
+# include <openssl/x509v3.h>
+#endif
+
+#ifndef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME
+# ifndef EXIM_HAVE_OPENSSL_CIPHER_GET_ID
+# define SSL_CIPHER_get_id(c) (c->id)
+# endif
+# ifndef MACRO_PREDEF
+# include "tls-cipher-stdname.c"
+# endif
+#endif
+
+/*************************************************
+* OpenSSL option parse *
+*************************************************/
+
+typedef struct exim_openssl_option {
+ uschar *name;
+ long value;
+} exim_openssl_option;
+/* We could use a macro to expand, but we need the ifdef and not all the
+options document which version they were introduced in. Policylet: include
+all options unless explicitly for DTLS, let the administrator choose which
+to apply.
+
+This list is current as of:
+ ==> 1.1.1c <==
+
+XXX could we autobuild this list, as with predefined-macros?
+Seems just parsing ssl.h for SSL_OP_.* would be enough (except to exclude DTLS).
+Also allow a numeric literal?
+*/
+static exim_openssl_option exim_openssl_options[] = {
+/* KEEP SORTED ALPHABETICALLY! */
+#ifdef SSL_OP_ALL
+ { US"all", (long) SSL_OP_ALL },
+#endif
+#ifdef SSL_OP_ALLOW_NO_DHE_KEX
+ { US"allow_no_dhe_kex", SSL_OP_ALLOW_NO_DHE_KEX },
+#endif
+#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
+ { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION },
+#endif
+#ifdef SSL_OP_CIPHER_SERVER_PREFERENCE
+ { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE },
+#endif
+#ifdef SSL_OP_CRYPTOPRO_TLSEXT_BUG
+ { US"cryptopro_tlsext_bug", SSL_OP_CRYPTOPRO_TLSEXT_BUG },
+#endif
+#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
+ { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS },
+#endif
+#ifdef SSL_OP_ENABLE_MIDDLEBOX_COMPAT
+ { US"enable_middlebox_compat", SSL_OP_ENABLE_MIDDLEBOX_COMPAT },
+#endif
+#ifdef SSL_OP_EPHEMERAL_RSA
+ { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA },
+#endif
+#ifdef SSL_OP_LEGACY_SERVER_CONNECT
+ { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT },
+#endif
+#ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
+ { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER },
+#endif
+#ifdef SSL_OP_MICROSOFT_SESS_ID_BUG
+ { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG },
+#endif
+#ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING
+ { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING },
+#endif
+#ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG
+ { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG },
+#endif
+#ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
+ { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG },
+#endif
+#ifdef SSL_OP_NO_ANTI_REPLAY
+ { US"no_anti_replay", SSL_OP_NO_ANTI_REPLAY },
+#endif
+#ifdef SSL_OP_NO_COMPRESSION
+ { US"no_compression", SSL_OP_NO_COMPRESSION },
+#endif
+#ifdef SSL_OP_NO_ENCRYPT_THEN_MAC
+ { US"no_encrypt_then_mac", SSL_OP_NO_ENCRYPT_THEN_MAC },
+#endif
+#ifdef SSL_OP_NO_RENEGOTIATION
+ { US"no_renegotiation", SSL_OP_NO_RENEGOTIATION },
+#endif
+#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
+ { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION },
+#endif
+#ifdef SSL_OP_NO_SSLv2
+ { US"no_sslv2", SSL_OP_NO_SSLv2 },
+#endif
+#ifdef SSL_OP_NO_SSLv3
+ { US"no_sslv3", SSL_OP_NO_SSLv3 },
+#endif
+#ifdef SSL_OP_NO_TICKET
+ { US"no_ticket", SSL_OP_NO_TICKET },
+#endif
+#ifdef SSL_OP_NO_TLSv1
+ { US"no_tlsv1", SSL_OP_NO_TLSv1 },
+#endif
+#ifdef SSL_OP_NO_TLSv1_1
+#if SSL_OP_NO_TLSv1_1 == 0x00000400L
+ /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */
+#warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
+#else
+ { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 },
+#endif
+#endif
+#ifdef SSL_OP_NO_TLSv1_2
+ { US"no_tlsv1_2", SSL_OP_NO_TLSv1_2 },
+#endif
+#ifdef SSL_OP_NO_TLSv1_3
+ { US"no_tlsv1_3", SSL_OP_NO_TLSv1_3 },
+#endif
+#ifdef SSL_OP_PRIORITIZE_CHACHA
+ { US"prioritize_chacha", SSL_OP_PRIORITIZE_CHACHA },
+#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
+#ifdef SSL_OP_SINGLE_ECDH_USE
+ { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE },
+#endif
+#ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG
+ { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG },
+#endif
+#ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
+ { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG },
+#endif
+#ifdef SSL_OP_TLS_BLOCK_PADDING_BUG
+ { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG },
+#endif
+#ifdef SSL_OP_TLS_D5_BUG
+ { US"tls_d5_bug", SSL_OP_TLS_D5_BUG },
+#endif
+#ifdef SSL_OP_TLS_ROLLBACK_BUG
+ { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG },
+#endif
+#ifdef SSL_OP_TLSEXT_PADDING
+ { US"tlsext_padding", SSL_OP_TLSEXT_PADDING },
+#endif
+};
+
+#ifndef MACRO_PREDEF
+static int exim_openssl_options_size = nelem(exim_openssl_options);
+#endif
+
+#ifdef MACRO_PREDEF
+void
+options_tls(void)
+{
+uschar buf[64];
+
+for (struct exim_openssl_option * o = exim_openssl_options;
+ o < exim_openssl_options + nelem(exim_openssl_options); o++)
+ {
+ /* Trailing X is workaround for problem with _OPT_OPENSSL_NO_TLSV1
+ being a ".ifdef _OPT_OPENSSL_NO_TLSV1_3" match */
+
+ spf(buf, sizeof(buf), US"_OPT_OPENSSL_%T_X", o->name);
+ builtin_macro_create(buf);
+ }
+
+# ifdef EXPERIMENTAL_TLS_RESUME
+builtin_macro_create_var(US"_RESUME_DECODE", RESUME_DECODE_STRING );
+# endif
+# ifdef SSL_OP_NO_TLSv1_3
+builtin_macro_create(US"_HAVE_TLS1_3");
+# endif
+# ifdef OPENSSL_BAD_SRVR_OURCERT
+builtin_macro_create(US"_TLS_BAD_MULTICERT_IN_OURCERT");
+# endif
+# ifdef EXIM_HAVE_OCSP
+builtin_macro_create(US"_HAVE_TLS_OCSP");
+builtin_macro_create(US"_HAVE_TLS_OCSP_LIST");
+# endif
+}
+#else
+
+/******************************************************************************/
+
/* Structure for collecting random data for seeding. */
typedef struct randstuff {
Simple case: client, `client_ctx`
As a client, we can be doing a callout or cut-through delivery while receiving
a message. So we have a client context, which should have options initialised
- from the SMTP Transport.
+ from the SMTP Transport. We may also concurrently want to make TLS connections
+ to utility daemons, so client-contexts are allocated and passed around in call
+ args rather than using a gobal.
Server:
There are two cases: with and without ServerNameIndication from the client.
configuration.
*/
-static SSL_CTX *client_ctx = NULL;
+typedef struct {
+ SSL_CTX * ctx;
+ SSL * ssl;
+ gstring * corked;
+} exim_openssl_client_tls_ctx;
+
static SSL_CTX *server_ctx = NULL;
-static SSL *client_ssl = NULL;
static SSL *server_ssl = NULL;
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
static char ssl_errstring[256];
-static int ssl_session_timeout = 200;
+static int ssl_session_timeout = 7200; /* Two hours */
static BOOL client_verify_optional = FALSE;
static BOOL server_verify_optional = FALSE;
static BOOL reexpand_tls_files_for_sni = FALSE;
+typedef struct ocsp_resp {
+ struct ocsp_resp * next;
+ OCSP_RESPONSE * resp;
+} ocsp_resplist;
+
typedef struct tls_ext_ctx_cb {
+ tls_support * tlsp;
uschar *certificate;
uschar *privatekey;
-#ifndef DISABLE_OCSP
BOOL is_server;
+#ifndef DISABLE_OCSP
+ STACK_OF(X509) *verify_stack; /* chain for verifying the proof */
union {
struct {
uschar *file;
- uschar *file_expanded;
- OCSP_RESPONSE *response;
+ const uschar *file_expanded;
+ ocsp_resplist *olist;
} server;
struct {
X509_STORE *verify_store; /* non-null if status requested */
uschar *server_cipher_list;
/* only passed down to tls_error: */
host_item *host;
- uschar * verify_cert_hostnames;
-#ifdef EXPERIMENTAL_EVENT
+ 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
implementation, for various reasons, which can be void * in the APIs.
For now, we hack around it. */
-tls_ext_ctx_cb *client_static_cbinfo = NULL;
+tls_ext_ctx_cb *client_static_cbinfo = NULL; /*XXX should not use static; multiple concurrent clients! */
tls_ext_ctx_cb *server_static_cbinfo = NULL;
static int
setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
- int (*cert_vfy_cb)(int, X509_STORE_CTX *) );
+ int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr );
/* Callbacks */
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
#endif
+
+/* Daemon-called, before every connection, key create/rotate */
+#ifdef EXPERIMENTAL_TLS_RESUME
+static void tk_init(void);
+static int tls_exdata_idx = -1;
+#endif
+
+void
+tls_daemon_init(void)
+{
+#ifdef EXPERIMENTAL_TLS_RESUME
+tk_init();
+#endif
+return;
+}
+
+
/*************************************************
* Handle TLS error *
*************************************************/
host NULL if setting up a server;
the connected host if setting up a client
msg error message or NULL if we should ask OpenSSL
+ errstr pointer to output error message
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, uschar ** errstr)
{
if (!msg)
{
- ERR_error_string(ERR_get_error(), ssl_errstring);
- msg = (uschar *)ssl_errstring;
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ msg = US ssl_errstring;
}
-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;
- }
+msg = string_sprintf("(%s): %s", prefix, msg);
+DEBUG(D_tls) debug_printf("TLS error '%s'\n", msg);
+if (errstr) *errstr = msg;
+return host ? FAIL : DEFER;
}
/*
Arguments:
- s SSL connection
+ s SSL connection (not used)
export not used
keylength keylength
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);
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
log_write(0, LOG_MAIN|LOG_PANIC, "TLS error (RSA_generate_key): %s",
ssl_errstring);
return NULL;
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++)
+for (int 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));
- debug_printf(" %s\n", name);
+ X509_NAME * sn = X509_get_subject_name(tmp_obj->data.x509);
+ if (X509_NAME_oneline(sn, CS name, sizeof(name)))
+ {
+ name[sizeof(name)-1] = '\0';
+ debug_printf(" %s\n", name);
+ }
}
}
}
*/
+#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");
+ tlsp->verify_override = TRUE;
+ }
+ 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
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,
- tls_support *tlsp, BOOL *calledp, BOOL *optionalp)
+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));
+if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)))
+ {
+ DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n");
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address);
+ return 0;
+ }
+dn[sizeof(dn)-1] = '\0';
-if (state == 0)
+tlsp->verify_override = FALSE;
+if (preverify_ok == 0)
{
- log_write(0, LOG_MAIN, "SSL verify error: depth=%d error=%s cert=%s",
- depth,
- X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)),
- txt);
+ uschar * extra = verify_mode ? string_sprintf(" (during %c-verify for [%s])",
+ *verify_mode, sender_host_address)
+ : US"";
+ log_write(0, LOG_MAIN, "[%s] SSL verify error%s: depth=%d error=%s cert=%s",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ extra, depth,
+ X509_verify_cert_error_string(X509_STORE_CTX_get_error(x509ctx)), 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");
+ tlsp->verify_override = TRUE;
}
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
{
- uschar * verify_cert_hostnames;
-
- tlsp->peerdn = txt;
- tlsp->peercert = X509_dup(cert);
+ const uschar * verify_cert_hostnames;
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
+ /* client, wanting hostname check */
{
+
+#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",
+ tlsp == &tls_out ? deliver_host_address : sender_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
{
+ uschar * extra = verify_mode
+ ? string_sprintf(" (during %c-verify for [%s])",
+ *verify_mode, sender_host_address)
+ : US"";
log_write(0, LOG_MAIN,
- "SSL verify error: certificate name mismatch: \"%s\"\n", txt);
+ "[%s] SSL verify error%s: certificate name mismatch: DN=\"%s\" H=\"%s\"",
+ tlsp == &tls_out ? deliver_host_address : sender_host_address,
+ extra, dn, verify_cert_hostnames);
*calledp = TRUE;
if (!*optionalp)
- return 0; /* reject */
- DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
+ {
+ if (!tlsp->peercert)
+ tlsp->peercert = X509_dup(cert); /* record failing cert */
+ return 0; /* reject */
+ }
+ DEBUG(D_tls) debug_printf("SSL verify name failure overridden (host in "
"tls_try_verify_hosts)\n");
+ tlsp->verify_override = TRUE;
}
-# endif
+ }
-#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);
- if (!*calledp) tlsp->certificate_verified = TRUE;
+ *calledp ? "" : " authenticated", dn);
*calledp = TRUE;
}
-return 1; /* accept, at least for this level */
+return 1; /* accept, at least for this level */
+}
+
+static int
+verify_callback_client(int preverify_ok, X509_STORE_CTX *x509ctx)
+{
+return verify_callback(preverify_ok, x509ctx, &tls_out,
+ &client_verify_callback_called, &client_verify_optional);
+}
+
+static int
+verify_callback_server(int preverify_ok, X509_STORE_CTX *x509ctx)
+{
+return verify_callback(preverify_ok, x509ctx, &tls_in,
+ &server_verify_callback_called, &server_verify_optional);
+}
+
+
+#ifdef SUPPORT_DANE
+
+/* This gets called *by* the dane library verify callback, which interposes
+itself.
+*/
+static int
+verify_callback_client_dane(int preverify_ok, X509_STORE_CTX * x509ctx)
+{
+X509 * cert = X509_STORE_CTX_get_current_cert(x509ctx);
+uschar dn[256];
+int depth = X509_STORE_CTX_get_error_depth(x509ctx);
+#ifndef DISABLE_EVENT
+BOOL dummy_called, optional = FALSE;
+#endif
+
+if (!X509_NAME_oneline(X509_get_subject_name(cert), CS dn, sizeof(dn)))
+ {
+ DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n");
+ log_write(0, LOG_MAIN, "[%s] SSL verify error: internal error",
+ deliver_host_address);
+ return 0;
+ }
+dn[sizeof(dn)-1] = '\0';
+
+DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n",
+ preverify_ok ? "ok":"BAD", depth, 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 (preverify_ok == 1)
+ {
+ tls_out.dane_verified = TRUE;
+#ifndef DISABLE_OCSP
+ if (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
+ }
+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 /*SUPPORT_DANE*/
+
+
+/*************************************************
+* Information callback *
+*************************************************/
+
+/* The SSL library functions call this from time to time to indicate what they
+are doing. We copy the string to the debugging output when TLS debugging has
+been requested.
+
+Arguments:
+ s the SSL connection
+ where
+ ret
+
+Returns: nothing
+*/
+
+static void
+info_callback(SSL *s, int where, int ret)
+{
+DEBUG(D_tls)
+ {
+ const uschar * str;
+
+ if (where & SSL_ST_CONNECT)
+ str = US"SSL_connect";
+ else if (where & SSL_ST_ACCEPT)
+ str = US"SSL_accept";
+ else
+ str = US"SSL info (undefined)";
+
+ if (where & SSL_CB_LOOP)
+ debug_printf("%s: %s\n", str, SSL_state_string_long(s));
+ else if (where & SSL_CB_ALERT)
+ debug_printf("SSL3 alert %s:%s:%s\n",
+ str = where & SSL_CB_READ ? US"read" : US"write",
+ SSL_alert_type_string_long(ret), SSL_alert_desc_string_long(ret));
+ else if (where & SSL_CB_EXIT)
+ if (ret == 0)
+ debug_printf("%s: failed in %s\n", str, SSL_state_string_long(s));
+ else if (ret < 0)
+ debug_printf("%s: error in %s\n", str, SSL_state_string_long(s));
+ else if (where & SSL_CB_HANDSHAKE_START)
+ debug_printf("%s: hshake start: %s\n", str, SSL_state_string_long(s));
+ else if (where & SSL_CB_HANDSHAKE_DONE)
+ debug_printf("%s: hshake done: %s\n", str, SSL_state_string_long(s));
+ }
+}
+
+#ifdef OPENSSL_HAVE_KEYLOG_CB
+static void
+keylog_callback(const SSL *ssl, const char *line)
+{
+char * filename;
+FILE * fp;
+DEBUG(D_tls) debug_printf("%.200s\n", line);
+if (!(filename = getenv("SSLKEYLOGFILE"))) return;
+if (!(fp = fopen(filename, "a"))) return;
+fprintf(fp, "%s\n", line);
+fclose(fp);
+}
+#endif
+
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+/* Manage the keysets used for encrypting the session tickets, on the server. */
+
+typedef struct { /* Session ticket encryption key */
+ uschar name[16];
+
+ const EVP_CIPHER * aes_cipher;
+ uschar aes_key[32]; /* size needed depends on cipher. aes_128 implies 128/8 = 16? */
+ const EVP_MD * hmac_hash;
+ uschar hmac_key[16];
+ time_t renew;
+ time_t expire;
+} exim_stek;
+
+static exim_stek exim_tk; /* current key */
+static exim_stek exim_tk_old; /* previous key */
+
+static void
+tk_init(void)
+{
+time_t t = time(NULL);
+
+if (exim_tk.name[0])
+ {
+ if (exim_tk.renew >= t) return;
+ exim_tk_old = exim_tk;
+ }
+
+if (f.running_in_test_harness) ssl_session_timeout = 6;
+
+DEBUG(D_tls) debug_printf("OpenSSL: %s STEK\n", exim_tk.name[0] ? "rotating" : "creating");
+if (RAND_bytes(exim_tk.aes_key, sizeof(exim_tk.aes_key)) <= 0) return;
+if (RAND_bytes(exim_tk.hmac_key, sizeof(exim_tk.hmac_key)) <= 0) return;
+if (RAND_bytes(exim_tk.name+1, sizeof(exim_tk.name)-1) <= 0) return;
+
+exim_tk.name[0] = 'E';
+exim_tk.aes_cipher = EVP_aes_256_cbc();
+exim_tk.hmac_hash = EVP_sha256();
+exim_tk.expire = t + ssl_session_timeout;
+exim_tk.renew = t + ssl_session_timeout/2;
+}
+
+static exim_stek *
+tk_current(void)
+{
+if (!exim_tk.name[0]) return NULL;
+return &exim_tk;
}
-static int
-verify_callback_client(int state, X509_STORE_CTX *x509ctx)
+static exim_stek *
+tk_find(const uschar * name)
{
-return verify_callback(state, x509ctx, &tls_out, &client_verify_callback_called, &client_verify_optional);
+return memcmp(name, exim_tk.name, sizeof(exim_tk.name)) == 0 ? &exim_tk
+ : memcmp(name, exim_tk_old.name, sizeof(exim_tk_old.name)) == 0 ? &exim_tk_old
+ : NULL;
}
+/* Callback for session tickets, on server */
static int
-verify_callback_server(int state, X509_STORE_CTX *x509ctx)
+ticket_key_callback(SSL * ssl, uschar key_name[16],
+ uschar * iv, EVP_CIPHER_CTX * ctx, HMAC_CTX * hctx, int enc)
{
-return verify_callback(state, x509ctx, &tls_in, &server_verify_callback_called, &server_verify_optional);
-}
+tls_support * tlsp = server_static_cbinfo->tlsp;
+exim_stek * key;
+if (enc)
+ {
+ DEBUG(D_tls) debug_printf("ticket_key_callback: create new session\n");
+ tlsp->resumption |= RESUME_CLIENT_REQUESTED;
-#ifdef EXPERIMENTAL_DANE
+ if (RAND_bytes(iv, EVP_MAX_IV_LENGTH) <= 0)
+ return -1; /* insufficient random */
-/* 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);
-static uschar txt[256];
-#ifdef EXPERIMENTAL_EVENT
-int depth = X509_STORE_CTX_get_error_depth(x509ctx);
-uschar * yield;
-#endif
+ if (!(key = tk_current())) /* current key doesn't exist or isn't valid */
+ return 0; /* key couldn't be created */
+ memcpy(key_name, key->name, 16);
+ DEBUG(D_tls) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - time(NULL));
+
+ /*XXX will want these dependent on the ssl session strength */
+ HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
+ key->hmac_hash, NULL);
+ EVP_EncryptInit_ex(ctx, key->aes_cipher, NULL, key->aes_key, iv);
-X509_NAME_oneline(X509_get_subject_name(cert), CS txt, sizeof(txt));
+ DEBUG(D_tls) debug_printf("ticket created\n");
+ return 1;
+ }
+else
+ {
+ time_t now = time(NULL);
-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("ticket_key_callback: retrieve session\n");
+ tlsp->resumption |= RESUME_CLIENT_SUGGESTED;
-#ifdef EXPERIMENTAL_EVENT
- if (client_static_cbinfo->event_action)
+ if (!(key = tk_find(key_name)) || key->expire < now)
{
- 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)
+ DEBUG(D_tls)
{
- X509_free(tls_out.peercert);
- tls_out.peercert = NULL;
+ debug_printf("ticket not usable (%s)\n", key ? "expired" : "not found");
+ if (key) debug_printf("STEK expire " TIME_T_FMT "\n", key->expire - now);
}
+ return 0;
}
-#endif
-
-if (state == 1)
- tls_out.dane_verified =
- tls_out.certificate_verified = TRUE;
-return 1;
-}
-
-#endif /*EXPERIMENTAL_DANE*/
-
-
-/*************************************************
-* Information callback *
-*************************************************/
-/* The SSL library functions call this from time to time to indicate what they
-are doing. We copy the string to the debugging output when TLS debugging has
-been requested.
-
-Arguments:
- s the SSL connection
- where
- ret
+ HMAC_Init_ex(hctx, key->hmac_key, sizeof(key->hmac_key),
+ key->hmac_hash, NULL);
+ EVP_DecryptInit_ex(ctx, key->aes_cipher, NULL, key->aes_key, iv);
-Returns: nothing
-*/
+ DEBUG(D_tls) debug_printf("ticket usable, STEK expire " TIME_T_FMT "\n", key->expire - now);
-static void
-info_callback(SSL *s, int where, int ret)
-{
-where = where;
-ret = ret;
-DEBUG(D_tls) debug_printf("SSL info: %s\n", SSL_state_string_long(s));
+ /* The ticket lifetime and renewal are the same as the STEK lifetime and
+ renewal, which is overenthusiastic. A factor of, say, 3x longer STEK would
+ be better. To do that we'd have to encode ticket lifetime in the name as
+ we don't yet see the restored session. Could check posthandshake for TLS1.3
+ and trigger a new ticket then, but cannot do that for TLS1.2 */
+ return key->renew < now ? 2 : 1;
+ }
}
+#endif
/* 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
+ errstr error string pointer
Returns: TRUE if OK (nothing to set up, or setup worked)
*/
static BOOL
-init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host)
+init_dh(SSL_CTX *sctx, uschar *dhparam, const host_item *host, uschar ** errstr)
{
BIO *bio;
DH *dh;
uschar *dhexpanded;
const char *pem;
+int dh_bitsize;
-if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded))
+if (!expand_check(dhparam, US"tls_dhparam", &dhexpanded, errstr))
return FALSE;
if (!dhexpanded || !*dhexpanded)
if (!(bio = BIO_new_file(CS dhexpanded, "r")))
{
tls_error(string_sprintf("could not read dhparams file %s", dhexpanded),
- host, US strerror(errno));
+ host, US strerror(errno), errstr);
return FALSE;
}
}
if (!(pem = std_dh_prime_named(dhexpanded)))
{
tls_error(string_sprintf("Unknown standard DH prime \"%s\"", dhexpanded),
- host, US strerror(errno));
+ host, US strerror(errno), errstr);
return FALSE;
}
bio = BIO_new_mem_buf(CS pem, -1);
{
BIO_free(bio);
tls_error(string_sprintf("Could not read tls_dhparams \"%s\"", dhexpanded),
- host, NULL);
+ host, NULL, errstr);
return FALSE;
}
+/* note: our default limit of 2236 is not a multiple of 8; the limit comes from
+ * an NSS limit, and the GnuTLS APIs handle bit-sizes fine, so we went with
+ * 2236. But older OpenSSL can only report in bytes (octets), not bits.
+ * If someone wants to dance at the edge, then they can raise the limit or use
+ * current libraries. */
+#ifdef EXIM_HAVE_OPENSSL_DH_BITS
+/* Added in commit 26c79d5641d; `git describe --contains` says OpenSSL_1_1_0-pre1~1022
+ * This predates OpenSSL_1_1_0 (before a, b, ...) so is in all 1.1.0 */
+dh_bitsize = DH_bits(dh);
+#else
+dh_bitsize = 8 * DH_size(dh);
+#endif
+
/* Even if it is larger, we silently return success rather than cause things
* to fail out, so that a too-large DH will not knock out all TLS; it's a
* debatable choice. */
-if ((8*DH_size(dh)) > tls_dh_max_bits)
+if (dh_bitsize > tls_dh_max_bits)
{
DEBUG(D_tls)
- debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d",
- 8*DH_size(dh), tls_dh_max_bits);
+ debug_printf("dhparams file %d bits, is > tls_dh_max_bits limit of %d\n",
+ dh_bitsize, tls_dh_max_bits);
}
else
{
SSL_CTX_set_tmp_dh(sctx, dh);
DEBUG(D_tls)
debug_printf("Diffie-Hellman initialized from %s with %d-bit prime\n",
- dhexpanded ? dhexpanded : US"default", 8*DH_size(dh));
+ dhexpanded ? dhexpanded : US"default", dh_bitsize);
}
DH_free(dh);
+/*************************************************
+* 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
+ errstr error string pointer
+
+Returns: TRUE if OK (nothing to set up, or setup worked)
+*/
+
+static BOOL
+init_ecdh(SSL_CTX * sctx, host_item * host, uschar ** errstr)
+{
+#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, errstr))
+ 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 = US"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, errstr);
+ return FALSE;
+ }
+
+if (!(ecdh = EC_KEY_new_by_curve_name(nid)))
+ {
+ tls_error(US"Unable to create ec curve", host, NULL, errstr);
+ 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, errstr);
+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.
Arguments:
sctx the SSL_CTX* to update
cbinfo various parts of session state
- expanded the filename putatively holding an OCSP response
+ filename the filename putatively holding an OCSP response
+ is_pem file is PEM format; otherwise is DER
*/
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 * filename, BOOL is_pem)
{
-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;
-cbinfo->u_ocsp.server.file_expanded = string_copy(expanded);
-if (cbinfo->u_ocsp.server.response)
- {
- OCSP_RESPONSE_free(cbinfo->u_ocsp.server.response);
- cbinfo->u_ocsp.server.response = NULL;
- }
+DEBUG(D_tls)
+ debug_printf("tls_ocsp_file (%s) '%s'\n", is_pem ? "PEM" : "DER", filename);
-bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb");
-if (!bio)
+if (!(bio = BIO_new_file(CS filename, "rb")))
{
DEBUG(D_tls) debug_printf("Failed to open OCSP response file \"%s\"\n",
- cbinfo->u_ocsp.server.file_expanded);
+ filename);
return;
}
-resp = d2i_OCSP_RESPONSE_bio(bio, NULL);
+if (is_pem)
+ {
+ uschar * data, * freep;
+ char * dummy;
+ long len;
+ if (!PEM_read_bio(bio, &dummy, &dummy, &data, &len))
+ {
+ DEBUG(D_tls) debug_printf("Failed to read PEM file \"%s\"\n",
+ filename);
+ return;
+ }
+debug_printf("read pem file\n");
+ freep = data;
+ resp = d2i_OCSP_RESPONSE(NULL, CUSS &data, len);
+ OPENSSL_free(freep);
+ }
+else
+ resp = d2i_OCSP_RESPONSE_bio(bio, NULL);
BIO_free(bio);
+
if (!resp)
{
DEBUG(D_tls) debug_printf("Error reading OCSP response.\n");
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)
+#ifdef notdef
+ {
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
+ OCSP_RESPONSE_print(bp, resp, 0); /* extreme debug: stapling content */
+ BIO_free(bp);
+ }
+#endif
+
+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) {
- ERR_error_string(ERR_get_error(), ssl_errstring);
+ DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
debug_printf("OCSP response verify failure: %s\n", US ssl_errstring);
}
goto bad;
(tls_certificate) and use that for OCSP_resp_find_status() (which finds the
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)
+I'm hoping to avoid reworking a bunch more of how we handle state here.
+
+XXX that will change when we add support for (TLS1.3) whole-chain stapling
+*/
+
+if (!(single_response = OCSP_resp_get0(basic_response, 0)))
{
DEBUG(D_tls)
debug_printf("Unable to get first response from OCSP basic response.\n");
}
supply_response:
- cbinfo->u_ocsp.server.response = resp;
+ /* Add the resp to the list used by tls_server_stapling_cb() */
+ {
+ ocsp_resplist ** op = &cbinfo->u_ocsp.server.olist, * oentry;
+ while (oentry = *op)
+ op = &oentry->next;
+ *op = oentry = store_get(sizeof(ocsp_resplist), FALSE);
+ oentry->next = NULL;
+ oentry->resp = resp;
+ }
return;
bad:
- if (running_in_test_harness)
+ if (f.running_in_test_harness)
{
extern char ** environ;
- uschar ** p;
- for (p = USS environ; *p != NULL; p++)
+ if (environ) for (uschar ** p = USS environ; *p; p++)
if (Ustrncmp(*p, "EXIM_TESTHARNESS_DISABLE_OCSPVALIDITYCHECK", 42) == 0)
{
DEBUG(D_tls) debug_printf("Supplying known bad OCSP response\n");
}
return;
}
+
+
+static void
+ocsp_free_response_list(tls_ext_ctx_cb * cbinfo)
+{
+for (ocsp_resplist * olist = cbinfo->u_ocsp.server.olist; olist;
+ olist = olist->next)
+ OCSP_RESPONSE_free(olist->resp);
+cbinfo->u_ocsp.server.olist = NULL;
+}
#endif /*!DISABLE_OCSP*/
+/* Create and install a selfsigned certificate, for use in server mode */
+
+static int
+tls_install_selfsign(SSL_CTX * sctx, uschar ** errstr)
+{
+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";
+if (!(rsa = rsa_callback(NULL, 0, 2048)))
+ 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), 1);
+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, errstr);
+ if (x509) X509_free(x509);
+ if (pkey) EVP_PKEY_free(pkey);
+ return DEFER;
+}
+
+
+
+
+static int
+tls_add_certfile(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, uschar * file,
+ uschar ** errstr)
+{
+DEBUG(D_tls) debug_printf("tls_certificate file '%s'\n", file);
+if (!SSL_CTX_use_certificate_chain_file(sctx, CS file))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_certificate_chain_file file=%s", file),
+ cbinfo->host, NULL, errstr);
+return 0;
+}
+
+static int
+tls_add_pkeyfile(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo, uschar * file,
+ uschar ** errstr)
+{
+DEBUG(D_tls) debug_printf("tls_privatekey file '%s'\n", file);
+if (!SSL_CTX_use_PrivateKey_file(sctx, CS file, SSL_FILETYPE_PEM))
+ return tls_error(string_sprintf(
+ "SSL_CTX_use_PrivateKey_file file=%s", file), cbinfo->host, NULL, errstr);
+return 0;
+}
+
+
/*************************************************
* Expand key and cert file specs *
*************************************************/
Arguments:
sctx the SSL_CTX* to update
cbinfo various parts of session state
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
-tls_expand_session_files(SSL_CTX *sctx, tls_ext_ctx_cb *cbinfo)
+tls_expand_session_files(SSL_CTX * sctx, tls_ext_ctx_cb * cbinfo,
+ uschar ** errstr)
{
-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;
+uschar * expanded;
-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->is_server) /* client */
+ return OK;
+ /* server */
+ if (tls_install_selfsign(sctx, errstr) != OK)
+ return DEFER;
}
+else
+ {
+ int err;
-if (cbinfo->privatekey != NULL &&
- !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded))
- return DEFER;
+ if ( !reexpand_tls_files_for_sni
+ && ( 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 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 (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded, errstr))
+ return DEFER;
-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 (expanded)
+ if (cbinfo->is_server)
+ {
+ const uschar * file_list = expanded;
+ int sep = 0;
+ uschar * file;
+#ifndef DISABLE_OCSP
+ const uschar * olist = cbinfo->u_ocsp.server.file;
+ int osep = 0;
+ uschar * ofile;
+ BOOL fmt_pem = FALSE;
+
+ if (olist)
+ if (!expand_check(olist, US"tls_ocsp_file", USS &olist, errstr))
+ return DEFER;
+ if (olist && !*olist)
+ olist = NULL;
+
+ if ( cbinfo->u_ocsp.server.file_expanded && olist
+ && (Ustrcmp(olist, cbinfo->u_ocsp.server.file_expanded) == 0))
+ {
+ DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n");
+ olist = NULL;
+ }
+ else
+ {
+ ocsp_free_response_list(cbinfo);
+ cbinfo->u_ocsp.server.file_expanded = olist;
+ }
+#endif
+
+ while (file = string_nextinlist(&file_list, &sep, NULL, 0))
+ {
+ if ((err = tls_add_certfile(sctx, cbinfo, file, errstr)))
+ return err;
#ifndef DISABLE_OCSP
-if (cbinfo->is_server && cbinfo->u_ocsp.server.file != NULL)
- {
- if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded))
+ if (olist)
+ if ((ofile = string_nextinlist(&olist, &osep, NULL, 0)))
+ {
+ if (Ustrncmp(ofile, US"PEM ", 4) == 0)
+ {
+ fmt_pem = TRUE;
+ ofile += 4;
+ }
+ else if (Ustrncmp(ofile, US"DER ", 4) == 0)
+ {
+ fmt_pem = FALSE;
+ ofile += 4;
+ }
+ ocsp_load_response(sctx, cbinfo, ofile, fmt_pem);
+ }
+ else
+ DEBUG(D_tls) debug_printf("ran out of ocsp file list\n");
+#endif
+ }
+ }
+ else /* would there ever be a need for multiple client certs? */
+ if ((err = tls_add_certfile(sctx, cbinfo, expanded, errstr)))
+ return err;
+
+ if ( cbinfo->privatekey
+ && !expand_check(cbinfo->privatekey, US"tls_privatekey", &expanded, errstr))
return DEFER;
- if (expanded != NULL && *expanded != 0)
- {
- 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 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)
+ if (cbinfo->is_server)
{
- DEBUG(D_tls)
- debug_printf("tls_ocsp_file value unchanged, using existing values.\n");
- } else {
- ocsp_load_response(sctx, cbinfo, expanded);
+ const uschar * file_list = expanded;
+ int sep = 0;
+ uschar * file;
+
+ while (file = string_nextinlist(&file_list, &sep, NULL, 0))
+ if ((err = tls_add_pkeyfile(sctx, cbinfo, file, errstr)))
+ return err;
}
- }
+ else /* would there ever be a need for multiple client certs? */
+ if ((err = tls_add_pkeyfile(sctx, cbinfo, expanded, errstr)))
+ return err;
}
-#endif
return OK;
}
arg Callback of "our" registered data
Returns: SSL_TLSEXT_ERR_{OK,ALERT_WARNING,ALERT_FATAL,NOACK}
+
+XXX might need to change to using ClientHello callback,
+per https://www.openssl.org/docs/manmaster/man3/SSL_client_hello_cb_fn.html
*/
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
int rc;
int old_pool = store_pool;
+uschar * dummy_errstr;
if (!servername)
return SSL_TLSEXT_ERR_OK;
/* Make the extension value available for expansion */
store_pool = POOL_PERM;
-tls_in.sni = string_copy(US servername);
+tls_in.sni = string_copy_taint(US servername, TRUE);
store_pool = old_pool;
if (!reexpand_tls_files_for_sni)
not confident that memcpy wouldn't break some internal reference counting.
Especially since there's a references struct member, which would be off. */
+#ifdef EXIM_HAVE_OPENSSL_TLS_METHOD
+if (!(server_sni = SSL_CTX_new(TLS_server_method())))
+#else
if (!(server_sni = SSL_CTX_new(SSLv23_server_method())))
+#endif
{
- ERR_error_string(ERR_get_error(), ssl_errstring);
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
DEBUG(D_tls) debug_printf("SSL_CTX_new() failed: %s\n", ssl_errstring);
- return SSL_TLSEXT_ERR_NOACK;
+ goto bad;
}
/* Not sure how many of these are actually needed, since SSL object
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 (cbinfo->server_cipher_list)
- SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list);
+
+if ( !init_dh(server_sni, cbinfo->dhparam, NULL, &dummy_errstr)
+ || !init_ecdh(server_sni, NULL, &dummy_errstr)
+ )
+ goto bad;
+
+if ( cbinfo->server_cipher_list
+ && !SSL_CTX_set_cipher_list(server_sni, CS cbinfo->server_cipher_list))
+ goto bad;
+
#ifndef DISABLE_OCSP
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, &dummy_errstr)) != OK)
+ goto bad;
/* 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))
- return SSL_TLSEXT_ERR_NOACK;
+if ((rc = tls_expand_session_files(server_sni, cbinfo, &dummy_errstr)) != OK)
+ goto bad;
DEBUG(D_tls) debug_printf("Switching SSL context.\n");
SSL_set_SSL_CTX(s, server_sni);
-
return SSL_TLSEXT_ERR_OK;
+
+bad: return SSL_TLSEXT_ERR_ALERT_FATAL;
}
#endif /* EXIM_HAVE_OPENSSL_TLSEXT */
static int
tls_server_stapling_cb(SSL *s, void *arg)
{
-const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
-uschar *response_der;
+const tls_ext_ctx_cb * cbinfo = (tls_ext_ctx_cb *) arg;
+ocsp_resplist * olist = cbinfo->u_ocsp.server.olist;
+uschar * response_der; /*XXX blob */
int response_der_len;
DEBUG(D_tls)
- debug_printf("Received TLS status request (OCSP stapling); %s response.",
- cbinfo->u_ocsp.server.response ? "have" : "lack");
+ debug_printf("Received TLS status request (OCSP stapling); %s response list\n",
+ olist ? "have" : "lack");
tls_in.ocsp = OCSP_NOT_RESP;
-if (!cbinfo->u_ocsp.server.response)
+if (!olist)
+ return SSL_TLSEXT_ERR_NOACK;
+
+#ifdef EXIM_HAVE_OPESSL_GET0_SERIAL
+ {
+ const X509 * cert_sent = SSL_get_certificate(s);
+ const ASN1_INTEGER * cert_serial = X509_get0_serialNumber(cert_sent);
+ const BIGNUM * cert_bn = ASN1_INTEGER_to_BN(cert_serial, NULL);
+ const X509_NAME * cert_issuer = X509_get_issuer_name(cert_sent);
+ uschar * chash;
+ uint chash_len;
+
+ for (; olist; olist = olist->next)
+ {
+ OCSP_BASICRESP * bs = OCSP_response_get1_basic(olist->resp);
+ const OCSP_SINGLERESP * single = OCSP_resp_get0(bs, 0);
+ const OCSP_CERTID * cid = OCSP_SINGLERESP_get0_id(single);
+ ASN1_INTEGER * res_cert_serial;
+ const BIGNUM * resp_bn;
+ ASN1_OCTET_STRING * res_cert_iNameHash;
+
+
+ (void) OCSP_id_get0_info(&res_cert_iNameHash, NULL, NULL, &res_cert_serial,
+ (OCSP_CERTID *) cid);
+ resp_bn = ASN1_INTEGER_to_BN(res_cert_serial, NULL);
+
+ DEBUG(D_tls)
+ {
+ debug_printf("cert serial: %s\n", BN_bn2hex(cert_bn));
+ debug_printf("resp serial: %s\n", BN_bn2hex(resp_bn));
+ }
+
+ if (BN_cmp(cert_bn, resp_bn) == 0)
+ {
+ DEBUG(D_tls) debug_printf("matched serial for ocsp\n");
+
+ /*XXX TODO: check the rest of the list for duplicate matches.
+ If any, need to also check the Issuer Name hash.
+ Without this, we will provide the wrong status in the case of
+ duplicate id. */
+
+ break;
+ }
+ DEBUG(D_tls) debug_printf("not match serial for ocsp\n");
+ }
+ if (!olist)
+ {
+ DEBUG(D_tls) debug_printf("failed to find match for ocsp\n");
+ return SSL_TLSEXT_ERR_NOACK;
+ }
+ }
+#else
+if (olist->next)
+ {
+ DEBUG(D_tls) debug_printf("OpenSSL version too early to support multi-leaf OCSP\n");
return SSL_TLSEXT_ERR_NOACK;
+ }
+#endif
+/*XXX could we do the i2d earlier, rather than during the callback? */
response_der = NULL;
-response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response,
- &response_der);
+response_der_len = i2d_OCSP_RESPONSE(olist->resp, &response_der);
if (response_der_len <= 0)
return SSL_TLSEXT_ERR_NOACK;
OCSP_BASICRESP * bs;
int i;
-DEBUG(D_tls) debug_printf("Received TLS status response (OCSP stapling):");
+DEBUG(D_tls) debug_printf("Received TLS status callback (OCSP stapling):\n");
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)
- log_write(0, LOG_MAIN, "Received TLS status callback, null content");
+ if (cbinfo->u_ocsp.client.verify_required && LOGGING(tls_cipher))
+ log_write(0, LOG_MAIN, "Required TLS certificate status not received");
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 (log_extra_selector & LX_tls_cipher)
+if (!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
+ {
+ tls_out.ocsp = OCSP_FAILED; /*XXX should use tlsp-> to permit concurrent outbound */
+ 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)))
+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");
*/
{
BIO * bp = NULL;
- int status, reason;
- ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
+#ifndef EXIM_HAVE_OCSP_RESP_COUNT
+ STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
+#endif
- DEBUG(D_tls) bp = BIO_new_fp(stderr, BIO_NOCLOSE);
+ DEBUG(D_tls) bp = BIO_new_fp(debug_file, 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 (log_extra_selector & LX_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;
- }
+ if ((i = OCSP_basic_verify(bs, cbinfo->verify_stack,
+ cbinfo->u_ocsp.client.verify_store, OCSP_NOEXPLICIT)) <= 0)
+ if (ERR_peek_error())
+ {
+ tls_out.ocsp = OCSP_FAILED;
+ if (LOGGING(tls_cipher)) log_write(0, LOG_MAIN,
+ "Received TLS cert status response, itself unverifiable: %s",
+ ERR_reason_error_string(ERR_peek_error()));
+ BIO_printf(bp, "OCSP response verify failure\n");
+ ERR_print_errors(bp);
+ OCSP_RESPONSE_print(bp, rsp, 0);
+ goto failed;
+ }
+ else
+ DEBUG(D_tls) debug_printf("no explicit trust for OCSP signing"
+ " in the root CA certificate; ignoring\n");
+
+ DEBUG(D_tls) debug_printf("OCSP response well-formed and signed OK\n");
- 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. */
+
+ for (int idx =
+#ifdef EXIM_HAVE_OCSP_RESP_COUNT
+ OCSP_resp_count(bs) - 1;
+#else
+ sk_OCSP_SINGLERESP_num(sresp) - 1;
+#endif
+ idx >= 0; idx--)
{
- STACK_OF(OCSP_SINGLERESP) * sresp = bs->tbsResponseData->responses;
- OCSP_SINGLERESP * single;
+ OCSP_SINGLERESP * single = OCSP_resp_get0(bs, idx);
+ int status, reason;
+ ASN1_GENERALIZEDTIME * rev, * thisupd, * nextupd;
- 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);
+ /*XXX so I can see putting a loop in here to handle a rsp with >1 singleresp
+ - but what happens with a GnuTLS-style input?
+
+ we could do with a debug label for each singleresp
+ - it has a certID with a serialNumber, but I see no API to get that
+ */
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) 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");
+ goto failed;
+ }
+
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;
+ continue; /* the idx loop */
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;
}
+
+ goto failed;
}
- out:
+
+ i = 1;
+ tls_out.ocsp = OCSP_VFIED;
+ goto good;
+
+ failed:
+ tls_out.ocsp = OCSP_FAILED;
+ i = cbinfo->u_ocsp.client.verify_required ? 0 : 1;
+ good:
BIO_free(bp);
}
* Initialize for TLS *
*************************************************/
+static void
+tls_openssl_init(void)
+{
+#ifdef EXIM_NEED_OPENSSL_INIT
+SSL_load_error_strings(); /* basic set up */
+OpenSSL_add_ssl_algorithms();
+#endif
+
+#if defined(EXIM_HAVE_SHA256) && !defined(OPENSSL_AUTO_SHA256)
+/* SHA256 is becoming ever more popular. This makes sure it gets added to the
+list of available digests. */
+EVP_add_digest(EVP_sha256());
+#endif
+}
+
+
+
/* Called from both server and client code, to do preliminary initialization
of the library. We allocate and return a context structure.
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
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
#ifndef DISABLE_OCSP
uschar *ocsp_file,
#endif
- address_item *addr, tls_ext_ctx_cb ** cbp)
+ address_item *addr, tls_ext_ctx_cb ** cbp,
+ tls_support * tlsp,
+ uschar ** errstr)
{
+SSL_CTX * ctx;
long init_options;
int rc;
-BOOL okay;
tls_ext_ctx_cb * cbinfo;
cbinfo = store_malloc(sizeof(tls_ext_ctx_cb));
+cbinfo->tlsp = tlsp;
cbinfo->certificate = certificate;
cbinfo->privatekey = privatekey;
+cbinfo->is_server = host==NULL;
#ifndef DISABLE_OCSP
-if ((cbinfo->is_server = host==NULL))
+cbinfo->verify_stack = NULL;
+if (!host)
{
cbinfo->u_ocsp.server.file = ocsp_file;
cbinfo->u_ocsp.server.file_expanded = NULL;
- cbinfo->u_ocsp.server.response = NULL;
+ cbinfo->u_ocsp.server.olist = NULL;
}
else
cbinfo->u_ocsp.client.verify_store = NULL;
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)
-/* SHA256 is becoming ever more popular. This makes sure it gets added to the
-list of available digests. */
-EVP_add_digest(EVP_sha256());
-#endif
+tls_openssl_init();
/* Create a context.
The OpenSSL docs in 1.0.1b have not been updated to clarify TLS variant
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());
-
-if (*ctxp == NULL) return tls_error(US"SSL_CTX_new", host, NULL);
+#ifdef EXIM_HAVE_OPENSSL_TLS_METHOD
+if (!(ctx = SSL_CTX_new(host ? TLS_client_method() : TLS_server_method())))
+#else
+if (!(ctx = SSL_CTX_new(host ? SSLv23_client_method() : SSLv23_server_method())))
+#endif
+ return tls_error(US"SSL_CTX_new", host, NULL, errstr);
/* 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
gettimeofday(&r.tv, NULL);
r.p = getpid();
- RAND_seed((uschar *)(&r), sizeof(r));
- RAND_seed((uschar *)big_buffer, big_buffer_size);
- if (addr != NULL) RAND_seed((uschar *)addr, sizeof(addr));
+ RAND_seed(US (&r), sizeof(r));
+ RAND_seed(US big_buffer, big_buffer_size);
+ if (addr != NULL) RAND_seed(US addr, sizeof(addr));
if (!RAND_status())
return tls_error(US"RAND_status", host,
- US"unable to seed random number generator");
+ US"unable to seed random number generator", errstr);
}
/* 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(ctx, (void (*)())info_callback);
+#if defined(EXIM_HAVE_OPESSL_TRACE) && !defined(OPENSSL_NO_SSL_TRACE)
+ /* this needs a debug build of OpenSSL */
+ SSL_CTX_set_msg_callback(ctx, (void (*)())SSL_trace);
+#endif
+#ifdef OPENSSL_HAVE_KEYLOG_CB
+ SSL_CTX_set_keylog_callback(ctx, (void (*)())keylog_callback);
+#endif
+ }
/* Automatically re-try reads/writes after renegotiation. */
-(void) SSL_CTX_set_mode(*ctxp, SSL_MODE_AUTO_RETRY);
+(void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY);
/* Apply administrator-supplied work-arounds.
Historically we applied just one requested option,
No OpenSSL version number checks: the options we accept depend upon the
availability of the option value macros from OpenSSL. */
-okay = tls_openssl_options_parse(openssl_options, &init_options);
-if (!okay)
- return tls_error(US"openssl_options parsing failed", host, NULL);
+if (!tls_openssl_options_parse(openssl_options, &init_options))
+ return tls_error(US"openssl_options parsing failed", host, NULL, errstr);
+#ifdef EXPERIMENTAL_TLS_RESUME
+tlsp->resumption = RESUME_SUPPORTED;
+#endif
if (init_options)
{
+#ifdef EXPERIMENTAL_TLS_RESUME
+ /* Should the server offer session resumption? */
+ if (!host && verify_check_host(&tls_resumption_hosts) == OK)
+ {
+ DEBUG(D_tls) debug_printf("tls_resumption_hosts overrides openssl_options\n");
+ init_options &= ~SSL_OP_NO_TICKET;
+ tlsp->resumption |= RESUME_SERVER_TICKET; /* server will give ticket on request */
+ tlsp->host_resumable = TRUE;
+ }
+#endif
+
DEBUG(D_tls) debug_printf("setting SSL CTX options: %#lx\n", init_options);
- if (!(SSL_CTX_set_options(*ctxp, init_options)))
+ if (!(SSL_CTX_set_options(ctx, init_options)))
return tls_error(string_sprintf(
- "SSL_CTX_set_option(%#lx)", init_options), host, NULL);
+ "SSL_CTX_set_option(%#lx)", init_options), host, NULL, errstr);
}
else
DEBUG(D_tls) debug_printf("no SSL CTX options to set\n");
+/* We'd like to disable session cache unconditionally, but foolish Outlook
+Express clients then give up the first TLS connection and make a second one
+(which works). Only when there is an IMAP service on the same machine.
+Presumably OE is trying to use the cache for A on B. Leave it enabled for
+now, until we work out a decent way of presenting control to the config. It
+will never be used because we use a new context every time. */
+#ifdef notdef
+(void) SSL_CTX_set_session_cache_mode(ctx, SSL_SESS_CACHE_OFF);
+#endif
+
/* Initialize with DH parameters if supplied */
+/* Initialize ECDH temp key parameter selection */
-if (!init_dh(*ctxp, dhparam, host)) return DEFER;
+if ( !init_dh(ctx, dhparam, host, errstr)
+ || !init_ecdh(ctx, host, errstr)
+ )
+ 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(ctx, cbinfo, errstr)) != 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
-if (host == NULL) /* server */
+# 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) /* server */
{
# ifndef DISABLE_OCSP
- /* We check u_ocsp.server.file, not server.response, because we care about if
+ /* We check u_ocsp.server.file, not server.olist, 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->u_ocsp.server.file)
{
- SSL_CTX_set_tlsext_status_cb(server_ctx, tls_server_stapling_cb);
- SSL_CTX_set_tlsext_status_arg(server_ctx, cbinfo);
+ SSL_CTX_set_tlsext_status_cb(ctx, tls_server_stapling_cb);
+ SSL_CTX_set_tlsext_status_arg(ctx, cbinfo);
}
# 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);
+ SSL_CTX_set_tlsext_servername_callback(ctx, tls_servername_cb);
+ SSL_CTX_set_tlsext_servername_arg(ctx, cbinfo);
}
# ifndef DISABLE_OCSP
else /* client */
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);
+ SSL_CTX_set_tlsext_status_cb(ctx, tls_client_stapling_cb);
+ SSL_CTX_set_tlsext_status_arg(ctx, cbinfo);
}
# endif
#endif
cbinfo->verify_cert_hostnames = NULL;
+#ifdef EXIM_HAVE_EPHEM_RSA_KEX
/* Set up the RSA callback */
+SSL_CTX_set_tmp_rsa_callback(ctx, rsa_callback);
+#endif
-SSL_CTX_set_tmp_rsa_callback(*ctxp, rsa_callback);
-
-/* Finally, set the timeout, and we are done */
+/* Finally, set the session cache timeout, and we are done.
+The period appears to be also used for (server-generated) session tickets */
-SSL_CTX_set_timeout(*ctxp, ssl_session_timeout);
+SSL_CTX_set_timeout(ctx, ssl_session_timeout);
DEBUG(D_tls) debug_printf("Initialized TLS\n");
*cbp = cbinfo;
+*ctxp = ctx;
return OK;
}
/*
Argument: pointer to an SSL structure for the connection
- buffer to use for answer
- size of buffer
pointer to number of bits for cipher
-Returns: nothing
+Returns: pointer to allocated string in perm-pool
*/
-static void
-construct_cipher_name(SSL *ssl, uschar *cipherbuf, int bsize, int *bits)
+static uschar *
+construct_cipher_name(SSL * ssl, const uschar * ver, int * bits)
{
-/* With OpenSSL 1.0.0a, this needs to be const but the documentation doesn't
+int pool = store_pool;
+/* With OpenSSL 1.0.0a, 'c' needs to be const but the documentation doesn't
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;
-const uschar *ver;
-ver = (const uschar *)SSL_get_version(ssl);
+const SSL_CIPHER * c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl);
+uschar * s;
-c = (const SSL_CIPHER *) SSL_get_current_cipher(ssl);
SSL_CIPHER_get_bits(c, bits);
-string_format(cipherbuf, bsize, "%s:%s:%u", ver,
- SSL_CIPHER_get_name(c), *bits);
+store_pool = POOL_PERM;
+s = string_sprintf("%s:%s:%u", ver, SSL_CIPHER_get_name(c), *bits);
+store_pool = pool;
+DEBUG(D_tls) debug_printf("Cipher: %s\n", s);
+return s;
+}
+
+
+/* Get IETF-standard name for ciphersuite.
+Argument: pointer to an SSL structure for the connection
+Returns: pointer to string
+*/
+
+static const uschar *
+cipher_stdname_ssl(SSL * ssl)
+{
+#ifdef EXIM_HAVE_OPENSSL_CIPHER_STD_NAME
+return CUS SSL_CIPHER_standard_name(SSL_get_current_cipher(ssl));
+#else
+ushort id = 0xffff & SSL_CIPHER_get_id(SSL_get_current_cipher(ssl));
+return cipher_stdname(id >> 8, id & 0xff);
+#endif
+}
+
+
+static const uschar *
+tlsver_name(SSL * ssl)
+{
+uschar * s, * p;
+int pool = store_pool;
+
+store_pool = POOL_PERM;
+s = string_copy(US SSL_get_version(ssl));
+store_pool = pool;
+if ((p = Ustrchr(s, 'v'))) /* TLSv1.2 -> TLS1.2 */
+ for (;; p++) if (!(*p = p[1])) break;
+return CUS s;
+}
+
+
+static void
+peer_cert(SSL * ssl, tls_support * tlsp, uschar * peerdn, unsigned siz)
+{
+/*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. */
+
+tlsp->peerdn = NULL;
-DEBUG(D_tls) debug_printf("Cipher: %s\n", cipherbuf);
+/* 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)
+ if (!X509_NAME_oneline(X509_get_subject_name(tlsp->peercert), CS peerdn, siz))
+ { DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); }
+ else
+ {
+ int oldpool = store_pool;
+
+ peerdn[siz-1] = '\0'; /* paranoia */
+ store_pool = POOL_PERM;
+ tlsp->peerdn = string_copy(peerdn);
+ store_pool = oldpool;
+
+ /* We used to set CV in the cert-verify callbacks (either plain or dane)
+ but they don't get called on session-resumption. So use the official
+ interface, which uses the resumed value. Unfortunately this claims verified
+ when it actually failed but we're in try-verify mode, due to us wanting the
+ knowlege that it failed so needing to have the callback and forcing a
+ permissive return. If we don't force it, the TLS startup is failed.
+ The extra bit of information is set in verify_override in the cb, stashed
+ for resumption next to the TLS session, and used here. */
+
+ if (!tlsp->verify_override)
+ tlsp->certificate_verified =
+#ifdef SUPPORT_DANE
+ tlsp->dane_verified ||
+#endif
+ SSL_get_verify_result(ssl) == X509_V_OK;
+ }
}
* Set up for verifying certificates *
*************************************************/
-/* Called by both client and server startup
+#ifndef DISABLE_OCSP
+/* 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;
+
+while (sk_X509_num(verify_stack) > 0)
+ X509_free(sk_X509_pop(verify_stack));
+
+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;
+}
+#endif
+
+
+
+/* Called by both client and server startup; on the server possibly
+repeated after a Server Name Indication.
Arguments:
sctx SSL_CTX* to initialise
optional TRUE if called from a server for a host in tls_try_verify_hosts;
otherwise passed as FALSE
cert_vfy_cb Callback function for certificate verification
+ errstr error string pointer
Returns: OK/DEFER/FAIL
*/
static int
setup_certs(SSL_CTX *sctx, uschar *certs, uschar *crl, host_item *host, BOOL optional,
- int (*cert_vfy_cb)(int, X509_STORE_CTX *) )
+ int (*cert_vfy_cb)(int, X509_STORE_CTX *), uschar ** errstr)
{
uschar *expcerts, *expcrl;
-if (!expand_check(certs, US"tls_verify_certificates", &expcerts))
+if (!expand_check(certs, US"tls_verify_certificates", &expcerts, errstr))
return DEFER;
+DEBUG(D_tls) debug_printf("tls_verify_certificates: %s\n", expcerts);
-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);
+ return tls_error(US"SSL_CTX_set_default_verify_paths", host, NULL, errstr);
- if (Ustat(expcerts, &statbuf) < 0)
- {
- log_write(0, LOG_MAIN|LOG_PANIC,
- "failed to stat %s for certificates", expcerts);
- return DEFER;
- }
- else
+ if (Ustrcmp(expcerts, "system") != 0)
{
- 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. */
+
+/*XXX Glitch! The file here is tls_verify_certs: the chain for verifying the client cert.
+This is inconsistent with the need to verify the OCSP proof of the server cert.
+*/
+
+ 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 chain from %s", file);
+ return DEFER;
+ }
+#endif
+ }
+
+ /* If a certificate file is empty, the load 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, errstr);
+
+ /* On the server 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);
+
+ if (!host) SSL_CTX_set_client_CA_list(sctx, names);
+ DEBUG(D_tls) debug_printf("Added %d certificate authorities.\n",
+ sk_X509_NAME_num(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 (!expand_check(crl, US"tls_crl", &expcrl, errstr)) return DEFER;
+ if (expcrl && *expcrl)
{
struct stat statbufcrl;
if (Ustat(expcrl, &statbufcrl) < 0)
DEBUG(D_tls) debug_printf("SSL CRL value is a file %s\n", file);
}
if (X509_STORE_load_locations(cvstore, CS file, CS dir) == 0)
- return tls_error(US"X509_STORE_load_locations", host, NULL);
+ return tls_error(US"X509_STORE_load_locations", host, NULL, errstr);
/* setting the flags to check against the complete crl chain */
}
}
- #endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
+#endif /* OPENSSL_VERSION_NUMBER > 0x00907000L */
/* If verification is optional, don't fail if no certificate */
SSL_CTX_set_verify(sctx,
- SSL_VERIFY_PEER | (optional? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT),
+ SSL_VERIFY_PEER | (optional ? 0 : SSL_VERIFY_FAIL_IF_NO_PEER_CERT),
cert_vfy_cb);
}
Arguments:
require_ciphers allowed ciphers
+ errstr pointer to error message
Returns: OK on success
DEFER for errors before the start of the negotiation
- FAIL for errors during the negotation; the server can't
+ FAIL for errors during the negotiation; the server can't
continue running.
*/
int
-tls_server_start(const uschar *require_ciphers)
+tls_server_start(const uschar * require_ciphers, uschar ** errstr)
{
int rc;
-uschar *expciphers;
-tls_ext_ctx_cb *cbinfo;
-static uschar cipherbuf[256];
+uschar * expciphers;
+tls_ext_ctx_cb * cbinfo;
+static uschar peerdn[256];
/* Check for previous activation */
-if (tls_in.active >= 0)
+if (tls_in.active.sock >= 0)
{
- tls_error(US"STARTTLS received after TLS started", NULL, US"");
- smtp_printf("554 Already in TLS\r\n");
+ tls_error(US"STARTTLS received after TLS started", NULL, US"", errstr);
+ smtp_printf("554 Already in TLS\r\n", FALSE);
return FAIL;
}
#ifndef DISABLE_OCSP
tls_ocsp_file,
#endif
- NULL, &server_static_cbinfo);
+ NULL, &server_static_cbinfo, &tls_in, errstr);
if (rc != OK) return rc;
cbinfo = server_static_cbinfo;
-if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(require_ciphers, US"tls_require_ciphers", &expciphers, errstr))
return FAIL;
/* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
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.
+
+XXX SSL_CTX_set_cipher_list() is replaced by SSL_CTX_set_ciphersuites()
+for TLS 1.3 . Since we do not call it at present we get the default list:
+TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256
*/
-if (expciphers != NULL)
+if (expciphers)
{
- uschar *s = expciphers;
- while (*s != 0) { if (*s == '_') *s = '-'; s++; }
+ for (uschar * s = expciphers; *s; s++ ) if (*s == '_') *s = '-';
DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
if (!SSL_CTX_set_cipher_list(server_ctx, CS expciphers))
- return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL);
+ return tls_error(US"SSL_CTX_set_cipher_list", NULL, NULL, errstr);
cbinfo->server_cipher_list = expciphers;
}
optional, set up appropriately. */
tls_in.certificate_verified = FALSE;
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_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, verify_callback_server);
+ FALSE, verify_callback_server, errstr);
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, verify_callback_server);
+ TRUE, verify_callback_server, errstr);
if (rc != OK) return rc;
server_verify_optional = TRUE;
}
+#ifdef EXPERIMENTAL_TLS_RESUME
+SSL_CTX_set_tlsext_ticket_key_cb(server_ctx, ticket_key_callback);
+/* despite working, appears to always return failure, so ignoring */
+#endif
+#ifdef OPENSSL_HAVE_NUM_TICKETS
+# ifdef EXPERIMENTAL_TLS_RESUME
+SSL_CTX_set_num_tickets(server_ctx, tls_in.host_resumable ? 1 : 0);
+# else
+SSL_CTX_set_num_tickets(server_ctx, 0); /* send no TLS1.3 stateful-tickets */
+# endif
+#endif
+
+
/* 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, errstr);
/* Warning: we used to SSL_clear(ssl) here, it was removed.
*
SSL_set_session_id_context(server_ssl, sid_ctx, Ustrlen(sid_ctx));
if (!tls_in.on_connect)
{
- smtp_printf("220 TLS go ahead\r\n");
+ smtp_printf("220 TLS go ahead\r\n", FALSE);
fflush(smtp_out);
}
DEBUG(D_tls) debug_printf("Calling SSL_accept\n");
sigalrm_seen = FALSE;
-if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
+if (smtp_receive_timeout > 0) ALARM(smtp_receive_timeout);
rc = SSL_accept(server_ssl);
-alarm(0);
+ALARM_CLR(0);
if (rc <= 0)
{
- tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL);
- if (ERR_get_error() == 0)
- log_write(0, LOG_MAIN,
- "TLS client disconnected cleanly (rejected our certificate?)");
- return FAIL;
+ int error = SSL_get_error(server_ssl, rc);
+ switch(error)
+ {
+ case SSL_ERROR_NONE:
+ break;
+
+ case SSL_ERROR_ZERO_RETURN:
+ DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
+ (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr);
+
+ if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN)
+ SSL_shutdown(server_ssl);
+
+ tls_close(NULL, TLS_NO_SHUTDOWN);
+ return FAIL;
+
+ /* Handle genuine errors */
+ case SSL_ERROR_SSL:
+ {
+ uschar * s = US"SSL_accept";
+ int r = ERR_GET_REASON(ERR_peek_error());
+ if ( r == SSL_R_WRONG_VERSION_NUMBER
+#ifdef SSL_R_VERSION_TOO_LOW
+ || r == SSL_R_VERSION_TOO_LOW
+#endif
+ || r == SSL_R_UNKNOWN_PROTOCOL || r == SSL_R_UNSUPPORTED_PROTOCOL)
+ s = string_sprintf("%s (%s)", s, SSL_get_version(server_ssl));
+ (void) tls_error(s, NULL, sigalrm_seen ? US"timed out" : NULL, errstr);
+ return FAIL;
+ }
+
+ default:
+ DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
+ if (error == SSL_ERROR_SYSCALL)
+ {
+ if (!errno)
+ {
+ *errstr = US"SSL_accept: TCP connection closed by peer";
+ return FAIL;
+ }
+ DEBUG(D_tls) debug_printf(" - syscall %s\n", strerror(errno));
+ }
+ (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr);
+ return FAIL;
+ }
}
DEBUG(D_tls) debug_printf("SSL_accept was successful\n");
+ERR_clear_error(); /* Even success can leave errors in the stack. Seen with
+ anon-authentication ciphersuite negotiated. */
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+if (SSL_session_reused(server_ssl))
+ {
+ tls_in.resumption |= RESUME_USED;
+ DEBUG(D_tls) debug_printf("Session reused\n");
+ }
+#endif
-/* TLS has been set up. Adjust the input functions to read via TLS,
-and initialize things. */
+/* TLS has been set up. Record data for the connection,
+adjust the input functions to read via TLS, and initialize things. */
+
+#ifdef SSL_get_extms_support
+tls_in.ext_master_secret = SSL_get_extms_support(server_ssl) == 1;
+#endif
+peer_cert(server_ssl, &tls_in, peerdn, sizeof(peerdn));
-construct_cipher_name(server_ssl, cipherbuf, sizeof(cipherbuf), &tls_in.bits);
-tls_in.cipher = cipherbuf;
+tls_in.ver = tlsver_name(server_ssl);
+tls_in.cipher = construct_cipher_name(server_ssl, tls_in.ver, &tls_in.bits);
+tls_in.cipher_stdname = cipher_stdname_ssl(server_ssl);
DEBUG(D_tls)
{
uschar buf[2048];
- if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)) != NULL)
+ if (SSL_get_shared_ciphers(server_ssl, CS buf, sizeof(buf)))
debug_printf("Shared ciphers: %s\n", buf);
+
+#ifdef EXIM_HAVE_OPENSSL_KEYLOG
+ {
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
+ SSL_SESSION_print_keylog(bp, SSL_get_session(server_ssl));
+ BIO_free(bp);
+ }
+#endif
+
+#ifdef EXIM_HAVE_SESSION_TICKET
+ {
+ SSL_SESSION * ss = SSL_get_session(server_ssl);
+ if (SSL_SESSION_has_ticket(ss)) /* 1.1.0 */
+ debug_printf("The session has a ticket, life %lu seconds\n",
+ SSL_SESSION_get_ticket_lifetime_hint(ss));
+ }
+#endif
}
/* Record the certificate we presented */
tls_in.ourcert = crt ? X509_dup(crt) : NULL;
}
+/* Channel-binding info for authenticators
+See description in https://paquier.xyz/postgresql-2/channel-binding-openssl/ */
+ {
+ uschar c, * s;
+ size_t len = SSL_get_peer_finished(server_ssl, &c, 0);
+ int old_pool = store_pool;
+
+ SSL_get_peer_finished(server_ssl, s = store_get((int)len, FALSE), len);
+ store_pool = POOL_PERM;
+ tls_in.channelbinding = b64encode_taint(CUS s, (int)len, FALSE);
+ store_pool = old_pool;
+ DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage %p\n", tls_in.channelbinding);
+ }
+
/* Only used by the server-side tls (tls_in), including tls_getc.
Client-side (tls_out) reads (seem to?) go via
smtp_read_response()/ip_recv().
Hence no need to duplicate for _in and _out.
*/
-ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size);
+if (!ssl_xfer_buffer) ssl_xfer_buffer = store_malloc(ssl_xfer_buffer_size);
ssl_xfer_buffer_lwm = ssl_xfer_buffer_hwm = 0;
-ssl_xfer_eof = ssl_xfer_error = 0;
+ssl_xfer_eof = ssl_xfer_error = FALSE;
receive_getc = tls_getc;
+receive_getbuf = tls_getbuf;
+receive_get_cache = tls_get_cache;
receive_ungetc = tls_ungetc;
receive_feof = tls_feof;
receive_ferror = tls_ferror;
receive_smtp_buffered = tls_smtp_buffered;
-tls_in.active = fileno(smtp_out);
+tls_in.active.sock = fileno(smtp_out);
+tls_in.active.tls_ctx = NULL; /* not using explicit ctx for server-side */
return OK;
}
static int
tls_client_basic_ctx_init(SSL_CTX * ctx,
- host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo
- )
+ host_item * host, smtp_transport_options_block * ob, tls_ext_ctx_cb * cbinfo,
+ uschar ** errstr)
{
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)
- || (verify_check_given_host(&ob->tls_verify_hosts, host) == OK)
+if ( ( !ob->tls_verify_hosts
+ && (!ob->tls_try_verify_hosts || !*ob->tls_try_verify_hosts)
+ )
+ || verify_check_given_host(CUSS &ob->tls_verify_hosts, host) == OK
)
client_verify_optional = FALSE;
-else if (verify_check_given_host(&ob->tls_try_verify_hosts, host) == OK)
+else if (verify_check_given_host(CUSS &ob->tls_try_verify_hosts, host) == OK)
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)
+ ob->tls_crl, host, client_verify_optional, verify_callback_client,
+ errstr)) != OK)
return rc;
-if (verify_check_given_host(&ob->tls_verify_cert_hostnames, host) == OK)
+if (verify_check_given_host(CUSS &ob->tls_verify_cert_hostnames, host) == OK)
{
- 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);
}
}
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
static int
-dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa)
+dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa, uschar ** errstr)
{
-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);
+ return tls_error(US"hostnames load", host, NULL, errstr);
-for (rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS);
- rr;
+for (dns_record * rr = dns_next_rr(dnsa, &dnss, RESET_ANSWERS); rr;
rr = dns_next_rr(dnsa, &dnss, RESET_NEXT)
- ) if (rr->type == T_TLSA)
+ ) if (rr->type == T_TLSA && rr->size > 3)
{
- uschar * p = rr->data;
+ const uschar * p = rr->data;
uint8_t usage, selector, mtype;
const char * mdname;
switch (DANESSL_add_tlsa(ssl, usage, selector, mdname, p, rr->size - 3))
{
default:
+ return tls_error(US"tlsa load", host, NULL, errstr);
case 0: /* action not taken */
- return tls_error(US"tlsa load", host, NULL);
case 1: break;
}
return OK;
log_write(0, LOG_MAIN, "DANE error: No usable TLSA records");
-return FAIL;
+return DEFER;
+}
+#endif /*SUPPORT_DANE*/
+
+
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+/* On the client, get any stashed session for the given IP from hints db
+and apply it to the ssl-connection for attempted resumption. */
+
+static void
+tls_retrieve_session(tls_support * tlsp, SSL * ssl, const uschar * key)
+{
+tlsp->resumption |= RESUME_SUPPORTED;
+if (tlsp->host_resumable)
+ {
+ dbdata_tls_session * dt;
+ int len;
+ open_db dbblock, * dbm_file;
+
+ tlsp->resumption |= RESUME_CLIENT_REQUESTED;
+ DEBUG(D_tls) debug_printf("checking for resumable session for %s\n", key);
+ if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE)))
+ {
+ /* key for the db is the IP */
+ if ((dt = dbfn_read_with_length(dbm_file, key, &len)))
+ {
+ SSL_SESSION * ss = NULL;
+ const uschar * sess_asn1 = dt->session;
+
+ len -= sizeof(dbdata_tls_session);
+ if (!(d2i_SSL_SESSION(&ss, &sess_asn1, (long)len)))
+ {
+ DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(),
+ ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("decoding session: %s\n", ssl_errstring);
+ }
+ }
+#ifdef EXIM_HAVE_SESSION_TICKET
+ else if ( SSL_SESSION_get_ticket_lifetime_hint(ss) + dt->time_stamp
+ < time(NULL))
+ {
+ DEBUG(D_tls) debug_printf("session expired\n");
+ dbfn_delete(dbm_file, key);
+ }
+#endif
+ else if (!SSL_set_session(ssl, ss))
+ {
+ DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(),
+ ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("applying session to ssl: %s\n", ssl_errstring);
+ }
+ }
+ else
+ {
+ DEBUG(D_tls) debug_printf("good session\n");
+ tlsp->resumption |= RESUME_CLIENT_SUGGESTED;
+ tlsp->verify_override = dt->verify_override;
+ tlsp->ocsp = dt->ocsp;
+ }
+ }
+ else
+ DEBUG(D_tls) debug_printf("no session record\n");
+ dbfn_close(dbm_file);
+ }
+ }
+}
+
+
+/* On the client, save the session for later resumption */
+
+static int
+tls_save_session_cb(SSL * ssl, SSL_SESSION * ss)
+{
+tls_ext_ctx_cb * cbinfo = SSL_get_ex_data(ssl, tls_exdata_idx);
+tls_support * tlsp;
+
+DEBUG(D_tls) debug_printf("tls_save_session_cb\n");
+
+if (!cbinfo || !(tlsp = cbinfo->tlsp)->host_resumable) return 0;
+
+# ifdef OPENSSL_HAVE_NUM_TICKETS
+if (SSL_SESSION_is_resumable(ss)) /* 1.1.1 */
+# endif
+ {
+ int len = i2d_SSL_SESSION(ss, NULL);
+ int dlen = sizeof(dbdata_tls_session) + len;
+ dbdata_tls_session * dt = store_get(dlen, TRUE);
+ uschar * s = dt->session;
+ open_db dbblock, * dbm_file;
+
+ DEBUG(D_tls) debug_printf("session is resumable\n");
+ tlsp->resumption |= RESUME_SERVER_TICKET; /* server gave us a ticket */
+
+ dt->verify_override = tlsp->verify_override;
+ dt->ocsp = tlsp->ocsp;
+ (void) i2d_SSL_SESSION(ss, &s); /* s gets bumped to end */
+
+ if ((dbm_file = dbfn_open(US"tls", O_RDWR, &dbblock, FALSE, FALSE)))
+ {
+ const uschar * key = cbinfo->host->address;
+ dbfn_delete(dbm_file, key);
+ dbfn_write(dbm_file, key, dt, dlen);
+ dbfn_close(dbm_file);
+ DEBUG(D_tls) debug_printf("wrote session (len %u) to db\n",
+ (unsigned)dlen);
+ }
+ }
+return 1;
+}
+
+
+static void
+tls_client_ctx_resume_prehandshake(
+ exim_openssl_client_tls_ctx * exim_client_ctx, tls_support * tlsp,
+ smtp_transport_options_block * ob, host_item * host)
+{
+/* Should the client request a session resumption ticket? */
+if (verify_check_given_host(CUSS &ob->tls_resumption_hosts, host) == OK)
+ {
+ tlsp->host_resumable = TRUE;
+
+ SSL_CTX_set_session_cache_mode(exim_client_ctx->ctx,
+ SSL_SESS_CACHE_CLIENT
+ | SSL_SESS_CACHE_NO_INTERNAL | SSL_SESS_CACHE_NO_AUTO_CLEAR);
+ SSL_CTX_sess_set_new_cb(exim_client_ctx->ctx, tls_save_session_cb);
+ }
+}
+
+static BOOL
+tls_client_ssl_resume_prehandshake(SSL * ssl, tls_support * tlsp,
+ host_item * host, uschar ** errstr)
+{
+if (tlsp->host_resumable)
+ {
+ DEBUG(D_tls)
+ debug_printf("tls_resumption_hosts overrides openssl_options, enabling tickets\n");
+ SSL_clear_options(ssl, SSL_OP_NO_TICKET);
+
+ tls_exdata_idx = SSL_get_ex_new_index(0, 0, 0, 0, 0);
+ if (!SSL_set_ex_data(ssl, tls_exdata_idx, client_static_cbinfo))
+ {
+ tls_error(US"set ex_data", host, NULL, errstr);
+ return FALSE;
+ }
+ debug_printf("tls_exdata_idx %d cbinfo %p\n", tls_exdata_idx, client_static_cbinfo);
+ }
+
+tlsp->resumption = RESUME_SUPPORTED;
+/* Pick up a previous session, saved on an old ticket */
+tls_retrieve_session(tlsp, ssl, host->address);
+return TRUE;
}
-#endif /*EXPERIMENTAL_DANE*/
+static void
+tls_client_resume_posthandshake(exim_openssl_client_tls_ctx * exim_client_ctx,
+ tls_support * tlsp)
+{
+if (SSL_session_reused(exim_client_ctx->ssl))
+ {
+ DEBUG(D_tls) debug_printf("The session was reused\n");
+ tlsp->resumption |= RESUME_USED;
+ }
+}
+#endif /* EXPERIMENTAL_TLS_RESUME */
/*************************************************
/* Called from the smtp transport after STARTTLS has been accepted.
-Argument:
- fd the fd of the connection
- host connected host (for messages)
- addr the first address
- 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
- because this is not a server
+Arguments:
+ cctx connection context
+ conn_args connection details
+ cookie datum for randomness; can be NULL
+ tlsp record details of TLS channel configuration here; must be non-NULL
+ errstr error string pointer
+
+Returns: TRUE for success with TLS session context set in connection context,
+ FALSE on error
*/
-int
-tls_client_start(int fd, host_item *host, address_item *addr,
- transport_instance *tb
-#ifdef EXPERIMENTAL_DANE
- , dns_answer * tlsa_dnsa
-#endif
- )
+BOOL
+tls_client_start(client_conn_ctx * cctx, smtp_connect_args * conn_args,
+ void * cookie, tls_support * tlsp, uschar ** errstr)
{
-smtp_transport_options_block * ob =
- (smtp_transport_options_block *)tb->options_block;
-static uschar txt[256];
+host_item * host = conn_args->host; /* for msgs and option-tests */
+transport_instance * tb = conn_args->tblock; /* always smtp or NULL */
+smtp_transport_options_block * ob = tb
+ ? (smtp_transport_options_block *)tb->options_block
+ : &smtp_transport_option_defaults;
+exim_openssl_client_tls_ctx * exim_client_ctx;
uschar * expciphers;
-X509 * server_cert;
int rc;
-static uschar cipherbuf[256];
+static uschar peerdn[256];
#ifndef DISABLE_OCSP
BOOL request_ocsp = FALSE;
BOOL require_ocsp = FALSE;
#endif
-#ifdef EXPERIMENTAL_DANE
-tls_out.tlsa_usage = 0;
+rc = store_pool;
+store_pool = POOL_PERM;
+exim_client_ctx = store_get(sizeof(exim_openssl_client_tls_ctx), FALSE);
+exim_client_ctx->corked = NULL;
+store_pool = rc;
+
+#ifdef SUPPORT_DANE
+tlsp->tlsa_usage = 0;
#endif
#ifndef DISABLE_OCSP
{
-# ifdef EXPERIMENTAL_DANE
- if ( tlsa_dnsa
+# ifdef SUPPORT_DANE
+ if ( conn_args->dane
&& ob->hosts_request_ocsp[0] == '*'
&& ob->hosts_request_ocsp[1] == '\0'
)
# endif
if ((require_ocsp =
- verify_check_given_host(&ob->hosts_require_ocsp, host) == OK))
+ verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK))
request_ocsp = TRUE;
else
-# ifdef EXPERIMENTAL_DANE
+# ifdef SUPPORT_DANE
if (!request_ocsp)
# endif
request_ocsp =
- verify_check_given_host(&ob->hosts_request_ocsp, host) == OK;
+ verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK;
}
#endif
-rc = tls_init(&client_ctx, host, NULL,
+rc = tls_init(&exim_client_ctx->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;
+ cookie, &client_static_cbinfo, tlsp, errstr);
+if (rc != OK) return FALSE;
-tls_out.certificate_verified = FALSE;
+tlsp->certificate_verified = FALSE;
client_verify_callback_called = FALSE;
-if (!expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
- &expciphers))
- return FAIL;
+expciphers = NULL;
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
+ {
+ /* We fall back to tls_require_ciphers if unset, empty or forced failure, but
+ other failures should be treated as problems. */
+ if (ob->dane_require_tls_ciphers &&
+ !expand_check(ob->dane_require_tls_ciphers, US"dane_require_tls_ciphers",
+ &expciphers, errstr))
+ return FALSE;
+ if (expciphers && *expciphers == '\0')
+ expciphers = NULL;
+ }
+#endif
+if (!expciphers &&
+ !expand_check(ob->tls_require_ciphers, US"tls_require_ciphers",
+ &expciphers, errstr))
+ return FALSE;
/* In OpenSSL, cipher components are separated by hyphens. In GnuTLS, they
are 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;
- while (*s != 0) { if (*s == '_') *s = '-'; s++; }
+ while (*s) { if (*s == '_') *s = '-'; s++; }
DEBUG(D_tls) debug_printf("required ciphers: %s\n", expciphers);
- if (!SSL_CTX_set_cipher_list(client_ctx, CS expciphers))
- return tls_error(US"SSL_CTX_set_cipher_list", host, NULL);
+ if (!SSL_CTX_set_cipher_list(exim_client_ctx->ctx, CS expciphers))
+ {
+ tls_error(US"SSL_CTX_set_cipher_list", host, NULL, errstr);
+ return FALSE;
+ }
}
-#ifdef EXPERIMENTAL_DANE
-if (tlsa_dnsa)
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
{
- SSL_CTX_set_verify(client_ctx,
+ SSL_CTX_set_verify(exim_client_ctx->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);
+ {
+ tls_error(US"library init", host, NULL, errstr);
+ return FALSE;
+ }
+ if (DANESSL_CTX_init(exim_client_ctx->ctx) <= 0)
+ {
+ tls_error(US"context init", host, NULL, errstr);
+ return FALSE;
+ }
}
else
#endif
- if ((rc = tls_client_basic_ctx_init(client_ctx, host, ob, client_static_cbinfo))
- != OK)
- return rc;
+ if (tls_client_basic_ctx_init(exim_client_ctx->ctx, host, ob,
+ client_static_cbinfo, errstr) != OK)
+ return FALSE;
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+tls_client_ctx_resume_prehandshake(exim_client_ctx, tlsp, ob, host);
+#endif
+
+
+if (!(exim_client_ctx->ssl = SSL_new(exim_client_ctx->ctx)))
+ {
+ tls_error(US"SSL_new", host, NULL, errstr);
+ return FALSE;
+ }
+SSL_set_session_id_context(exim_client_ctx->ssl, sid_ctx, Ustrlen(sid_ctx));
-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);
+SSL_set_fd(exim_client_ctx->ssl, cctx->sock);
+SSL_set_connect_state(exim_client_ctx->ssl);
if (ob->tls_sni)
{
- if (!expand_check(ob->tls_sni, US"tls_sni", &tls_out.sni))
- return FAIL;
- if (tls_out.sni == NULL)
+ if (!expand_check(ob->tls_sni, US"tls_sni", &tlsp->sni, errstr))
+ return FALSE;
+ if (!tlsp->sni)
{
DEBUG(D_tls) debug_printf("Setting TLS SNI forced to fail, not sending\n");
}
- else if (!Ustrlen(tls_out.sni))
- tls_out.sni = NULL;
+ else if (!Ustrlen(tlsp->sni))
+ tlsp->sni = NULL;
else
{
#ifdef EXIM_HAVE_OPENSSL_TLSEXT
- DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tls_out.sni);
- SSL_set_tlsext_host_name(client_ssl, tls_out.sni);
+ DEBUG(D_tls) debug_printf("Setting TLS SNI \"%s\"\n", tlsp->sni);
+ SSL_set_tlsext_host_name(exim_client_ctx->ssl, tlsp->sni);
#else
- DEBUG(D_tls)
- debug_printf("OpenSSL at build-time lacked SNI support, ignoring \"%s\"\n",
- tls_out.sni);
+ log_write(0, LOG_MAIN, "SNI unusable with this OpenSSL library version; ignoring \"%s\"\n",
+ tlsp->sni);
#endif
}
}
-#ifdef EXPERIMENTAL_DANE
-if (tlsa_dnsa)
- if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa)) != OK)
- return rc;
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
+ if (dane_tlsa_load(exim_client_ctx->ssl, host, &conn_args->tlsa_dnsa, errstr) != OK)
+ return FALSE;
#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
+# ifdef SUPPORT_DANE
if (request_ocsp)
{
const uschar * s;
{ /* 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;
+ require_ocsp = verify_check_given_host(CUSS &ob->hosts_require_ocsp, host) == OK;
request_ocsp = require_ocsp
- || verify_check_given_host(&ob->hosts_request_ocsp, host) == OK;
+ || verify_check_given_host(CUSS &ob->hosts_request_ocsp, host) == OK;
}
}
# endif
if (request_ocsp)
{
- SSL_set_tlsext_status_type(client_ssl, TLSEXT_STATUSTYPE_ocsp);
+ SSL_set_tlsext_status_type(exim_client_ctx->ssl, TLSEXT_STATUSTYPE_ocsp);
client_static_cbinfo->u_ocsp.client.verify_required = require_ocsp;
- tls_out.ocsp = OCSP_NOT_RESP;
+ tlsp->ocsp = OCSP_NOT_RESP;
}
#endif
-#ifdef EXPERIMENTAL_EVENT
-client_static_cbinfo->event_action = tb->event_action;
+#ifdef EXPERIMENTAL_TLS_RESUME
+if (!tls_client_ssl_resume_prehandshake(exim_client_ctx->ssl, tlsp, host,
+ errstr))
+ return FALSE;
+#endif
+
+#ifndef DISABLE_EVENT
+client_static_cbinfo->event_action = tb ? tb->event_action : NULL;
#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(ob->command_timeout);
-rc = SSL_connect(client_ssl);
-alarm(0);
+ALARM(ob->command_timeout);
+rc = SSL_connect(exim_client_ctx->ssl);
+ALARM_CLR(0);
-#ifdef EXPERIMENTAL_DANE
-if (tlsa_dnsa)
- DANESSL_cleanup(client_ssl);
+#ifdef SUPPORT_DANE
+if (conn_args->dane)
+ DANESSL_cleanup(exim_client_ctx->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");
+ {
+ tls_error(US"SSL_connect", host, sigalrm_seen ? US"timed out" : NULL, errstr);
+ return FALSE;
+ }
-/* 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)
+DEBUG(D_tls)
+ {
+ debug_printf("SSL_connect succeeded\n");
+#ifdef EXIM_HAVE_OPENSSL_KEYLOG
{
- 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... */
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
+ SSL_SESSION_print_keylog(bp, SSL_get_session(exim_client_ctx->ssl));
+ BIO_free(bp);
}
-else
- tls_out.peerdn = NULL;
+#endif
+ }
+
+#ifdef EXPERIMENTAL_TLS_RESUME
+tls_client_resume_posthandshake(exim_client_ctx, tlsp);
+#endif
+
+#ifdef SSL_get_extms_support
+tlsp->ext_master_secret = SSL_get_extms_support(exim_client_ctx->ssl) == 1;
+#endif
+peer_cert(exim_client_ctx->ssl, tlsp, peerdn, sizeof(peerdn));
-construct_cipher_name(client_ssl, cipherbuf, sizeof(cipherbuf), &tls_out.bits);
-tls_out.cipher = cipherbuf;
+tlsp->ver = tlsver_name(exim_client_ctx->ssl);
+tlsp->cipher = construct_cipher_name(exim_client_ctx->ssl, tlsp->ver, &tlsp->bits);
+tlsp->cipher_stdname = cipher_stdname_ssl(exim_client_ctx->ssl);
/* Record the certificate we presented */
{
- X509 * crt = SSL_get_certificate(client_ssl);
- tls_out.ourcert = crt ? X509_dup(crt) : NULL;
+ X509 * crt = SSL_get_certificate(exim_client_ctx->ssl);
+ tlsp->ourcert = crt ? X509_dup(crt) : NULL;
}
-tls_out.active = fd;
-return OK;
+/*XXX will this work with continued-TLS? */
+/* Channel-binding info for authenticators */
+ {
+ uschar c, * s;
+ size_t len = SSL_get_finished(exim_client_ctx->ssl, &c, 0);
+ int old_pool = store_pool;
+
+ SSL_get_finished(exim_client_ctx->ssl, s = store_get((int)len, TRUE), len);
+ store_pool = POOL_PERM;
+ tlsp->channelbinding = b64encode_taint(CUS s, (int)len, TRUE);
+ store_pool = old_pool;
+ DEBUG(D_tls) debug_printf("Have channel bindings cached for possible auth usage %p %p\n", tlsp->channelbinding, tlsp);
+ }
+
+tlsp->active.sock = cctx->sock;
+tlsp->active.tls_ctx = exim_client_ctx;
+cctx->tls_ctx = exim_client_ctx;
+return TRUE;
}
+static BOOL
+tls_refill(unsigned lim)
+{
+int error;
+int inbytes;
+
+DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl,
+ 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,
+ MIN(ssl_xfer_buffer_size, lim));
+error = SSL_get_error(server_ssl, inbytes);
+if (smtp_receive_timeout > 0) ALARM_CLR(0);
+
+if (had_command_timeout) /* set by signal handler */
+ smtp_command_timeout_exit(); /* does not return */
+if (had_command_sigterm)
+ smtp_command_sigterm_exit();
+if (had_data_timeout)
+ smtp_data_timeout_exit();
+if (had_data_sigint)
+ smtp_data_sigint_exit();
+
+/* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been
+closed down, not that the socket itself has been closed down. Revert to
+non-SSL handling. */
+
+switch(error)
+ {
+ case SSL_ERROR_NONE:
+ break;
+
+ case SSL_ERROR_ZERO_RETURN:
+ DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
+
+ if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN)
+ SSL_shutdown(server_ssl);
+
+ tls_close(NULL, TLS_NO_SHUTDOWN);
+ return FALSE;
+
+ /* Handle genuine errors */
+ case SSL_ERROR_SSL:
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring);
+ ssl_xfer_error = TRUE;
+ return FALSE;
+
+ default:
+ DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
+ DEBUG(D_tls) if (error == SSL_ERROR_SYSCALL)
+ debug_printf(" - syscall %s\n", strerror(errno));
+ ssl_xfer_error = TRUE;
+ return FALSE;
+ }
+
+#ifndef DISABLE_DKIM
+dkim_exim_verify_feed(ssl_xfer_buffer, inbytes);
+#endif
+ssl_xfer_buffer_hwm = inbytes;
+ssl_xfer_buffer_lwm = 0;
+return TRUE;
+}
+
+
/*************************************************
* TLS version of getc *
*************************************************/
/* 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)
- {
- int error;
- int inbytes;
+ if (!tls_refill(lim))
+ return ssl_xfer_error ? EOF : smtp_getc(lim);
- DEBUG(D_tls) debug_printf("Calling SSL_read(%p, %p, %u)\n", server_ssl,
- ssl_xfer_buffer, ssl_xfer_buffer_size);
+/* Something in the buffer; return next uschar */
- if (smtp_receive_timeout > 0) alarm(smtp_receive_timeout);
- inbytes = SSL_read(server_ssl, CS ssl_xfer_buffer, ssl_xfer_buffer_size);
- error = SSL_get_error(server_ssl, inbytes);
- alarm(0);
+return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
+}
- /* SSL_ERROR_ZERO_RETURN appears to mean that the SSL session has been
- closed down, not that the socket itself has been closed down. Revert to
- non-SSL handling. */
+uschar *
+tls_getbuf(unsigned * len)
+{
+unsigned size;
+uschar * buf;
- if (error == SSL_ERROR_ZERO_RETURN)
+if (ssl_xfer_buffer_lwm >= ssl_xfer_buffer_hwm)
+ if (!tls_refill(*len))
{
- DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
-
- receive_getc = smtp_getc;
- receive_ungetc = smtp_ungetc;
- receive_feof = smtp_feof;
- receive_ferror = smtp_ferror;
- receive_smtp_buffered = smtp_buffered;
-
- SSL_free(server_ssl);
- server_ssl = NULL;
- tls_in.active = -1;
- tls_in.bits = 0;
- tls_in.cipher = NULL;
- tls_in.peerdn = NULL;
- tls_in.sni = NULL;
-
- return smtp_getc();
+ if (!ssl_xfer_error) return smtp_getbuf(len);
+ *len = 0;
+ return NULL;
}
- /* Handle genuine errors */
-
- else if (error == SSL_ERROR_SSL)
- {
- ERR_error_string(ERR_get_error(), ssl_errstring);
- log_write(0, LOG_MAIN, "TLS error (SSL_read): %s", ssl_errstring);
- ssl_xfer_error = 1;
- return EOF;
- }
+if ((size = ssl_xfer_buffer_hwm - ssl_xfer_buffer_lwm) > *len)
+ size = *len;
+buf = &ssl_xfer_buffer[ssl_xfer_buffer_lwm];
+ssl_xfer_buffer_lwm += size;
+*len = size;
+return buf;
+}
- else if (error != SSL_ERROR_NONE)
- {
- DEBUG(D_tls) debug_printf("Got SSL error %d\n", error);
- ssl_xfer_error = 1;
- return EOF;
- }
+void
+tls_get_cache()
+{
#ifndef DISABLE_DKIM
- dkim_exim_verify_feed(ssl_xfer_buffer, inbytes);
+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
- ssl_xfer_buffer_hwm = inbytes;
- ssl_xfer_buffer_lwm = 0;
- }
+}
-/* Something in the buffer; return next uschar */
-return ssl_xfer_buffer[ssl_xfer_buffer_lwm++];
+BOOL
+tls_could_read(void)
+{
+return ssl_xfer_buffer_lwm < ssl_xfer_buffer_hwm || SSL_pending(server_ssl) > 0;
}
-
/*************************************************
* Read bytes from TLS channel *
*************************************************/
/*
Arguments:
+ ct_ctx client context pointer, or NULL for the one global server context
buff buffer of data
len size of buffer
Returns: the number of bytes read
- -1 after a failed read
+ -1 after a failed read, including EOF
Only used by the client-side TLS.
*/
int
-tls_read(BOOL is_server, uschar *buff, size_t len)
+tls_read(void * ct_ctx, uschar *buff, size_t len)
{
-SSL *ssl = is_server ? server_ssl : client_ssl;
+SSL * ssl = ct_ctx ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl : server_ssl;
int inbytes;
int error;
return -1;
}
else if (error != SSL_ERROR_NONE)
- {
return -1;
- }
return inbytes;
}
/*
Arguments:
- is_server channel specifier
+ ct_ctx client context pointer, or NULL for the one global server context
buff buffer of data
len number of bytes
+ more further data expected soon
Returns: the number of bytes after a successful write,
-1 after a failed write
-Used by both server-side and client-side TLS.
+Used by both server-side and client-side TLS. Calling with len zero and more unset
+will flush buffered writes; buff can be null for this case.
*/
int
-tls_write(BOOL is_server, const uschar *buff, size_t len)
+tls_write(void * ct_ctx, const uschar * buff, size_t len, BOOL more)
{
-int outbytes;
-int error;
-int left = len;
-SSL *ssl = is_server ? server_ssl : client_ssl;
+size_t olen = len;
+int outbytes, error;
+SSL * ssl = ct_ctx
+ ? ((exim_openssl_client_tls_ctx *)ct_ctx)->ssl : server_ssl;
+static gstring * server_corked = NULL;
+gstring ** corkedp = ct_ctx
+ ? &((exim_openssl_client_tls_ctx *)ct_ctx)->corked : &server_corked;
+gstring * corked = *corkedp;
+
+DEBUG(D_tls) debug_printf("%s(%p, %lu%s)\n", __FUNCTION__,
+ buff, (unsigned long)len, more ? ", more" : "");
+
+/* Lacking a CORK or MSG_MORE facility (such as GnuTLS has) we copy data when
+"more" is notified. This hack is only ok if small amounts are involved AND only
+one stream does it, in one context (i.e. no store reset). Currently it is used
+for the responses to the received SMTP MAIL , RCPT, DATA sequence, only.
+We support callouts done by the server process by using a separate client
+context for the stashed information. */
+/* + if PIPE_COMMAND, banner & ehlo-resp for smmtp-on-connect. Suspect there's
+a store reset there, so use POOL_PERM. */
+/* + if CHUNKING, cmds EHLO,MAIL,RCPT(s),BDAT */
+
+if ((more || corked))
+ {
+ if (!len) buff = US &error; /* dummy just so that string_catn is ok */
+
+#ifndef DISABLE_PIPE_CONNECT
+ int save_pool = store_pool;
+ store_pool = POOL_PERM;
+#endif
+
+ corked = string_catn(corked, buff, len);
+
+#ifndef DISABLE_PIPE_CONNECT
+ store_pool = save_pool;
+#endif
-DEBUG(D_tls) debug_printf("tls_do_write(%p, %d)\n", buff, left);
-while (left > 0)
+ if (more)
+ {
+ *corkedp = corked;
+ return len;
+ }
+ buff = CUS corked->s;
+ len = corked->ptr;
+ *corkedp = NULL;
+ }
+
+for (int left = len; left > 0;)
{
- DEBUG(D_tls) debug_printf("SSL_write(SSL, %p, %d)\n", buff, left);
+ DEBUG(D_tls) debug_printf("SSL_write(%p, %p, %d)\n", ssl, buff, left);
outbytes = SSL_write(ssl, CS buff, left);
error = SSL_get_error(ssl, outbytes);
DEBUG(D_tls) debug_printf("outbytes=%d error=%d\n", outbytes, error);
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;
+ case SSL_ERROR_NONE: /* the usual case */
+ left -= outbytes;
+ buff += outbytes;
+ break;
- case SSL_ERROR_NONE:
- left -= outbytes;
- buff += outbytes;
- break;
+ case SSL_ERROR_SSL:
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ log_write(0, LOG_MAIN, "TLS error (SSL_write): %s", ssl_errstring);
+ return -1;
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"<unknown>",
- strerror(errno));
+ log_write(0, LOG_MAIN, "SSL_write: (from %s) syscall: %s",
+ sender_fullhost ? sender_fullhost : US"<unknown>",
+ 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;
+return olen;
}
daemon, to shut down the TLS library, without actually doing a shutdown (which
would tamper with the SSL session in the parent process).
-Arguments: TRUE if SSL_shutdown is to be called
+Arguments:
+ ct_ctx client TLS context pointer, or NULL for the one global server context
+ shutdown 1 if TLS close-alert is to be sent,
+ 2 if also response to be waited for
+
Returns: nothing
Used by both server-side and client-side TLS.
*/
void
-tls_close(BOOL is_server, BOOL shutdown)
+tls_close(void * ct_ctx, int shutdown)
{
-SSL **sslp = is_server ? &server_ssl : &client_ssl;
-int *fdp = is_server ? &tls_in.active : &tls_out.active;
+exim_openssl_client_tls_ctx * o_ctx = ct_ctx;
+SSL_CTX **ctxp = o_ctx ? &o_ctx->ctx : &server_ctx;
+SSL **sslp = o_ctx ? &o_ctx->ssl : &server_ssl;
+int *fdp = o_ctx ? &tls_out.active.sock : &tls_in.active.sock;
if (*fdp < 0) return; /* TLS was not active */
if (shutdown)
{
- DEBUG(D_tls) debug_printf("tls_close(): shutting down SSL\n");
- SSL_shutdown(*sslp);
+ int rc;
+ DEBUG(D_tls) debug_printf("tls_close(): shutting down TLS%s\n",
+ shutdown > 1 ? " (with response-wait)" : "");
+
+ if ( (rc = SSL_shutdown(*sslp)) == 0 /* send "close notify" alert */
+ && shutdown > 1)
+ {
+ ALARM(2);
+ rc = SSL_shutdown(*sslp); /* wait for response */
+ ALARM_CLR(0);
+ }
+
+ if (rc < 0) DEBUG(D_tls)
+ {
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ debug_printf("SSL_shutdown: %s\n", ssl_errstring);
+ }
+ }
+
+if (!o_ctx) /* server side */
+ {
+#ifndef DISABLE_OCSP
+ sk_X509_pop_free(server_static_cbinfo->verify_stack, X509_free);
+ server_static_cbinfo->verify_stack = NULL;
+#endif
+
+ receive_getc = smtp_getc;
+ receive_getbuf = smtp_getbuf;
+ receive_get_cache = smtp_get_cache;
+ receive_ungetc = smtp_ungetc;
+ receive_feof = smtp_feof;
+ receive_ferror = smtp_ferror;
+ receive_smtp_buffered = smtp_buffered;
+ tls_in.active.tls_ctx = NULL;
+ tls_in.sni = NULL;
+ /* Leave bits, peercert, cipher, peerdn, certificate_verified set, for logging */
}
+SSL_CTX_free(*ctxp);
SSL_free(*sslp);
+*ctxp = NULL;
*sslp = NULL;
-
*fdp = -1;
}
SSL_CTX *ctx;
uschar *s, *expciphers, *err;
-/* this duplicates from tls_init(), we need a better "init just global
-state, for no specific purpose" singleton function of our own */
-
-SSL_load_error_strings();
-OpenSSL_add_ssl_algorithms();
-#if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
-/* SHA256 is becoming ever more popular. This makes sure it gets added to the
-list of available digests. */
-EVP_add_digest(EVP_sha256());
-#endif
+tls_openssl_init();
if (!(tls_require_ciphers && *tls_require_ciphers))
return NULL;
-if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers))
+if (!expand_check(tls_require_ciphers, US"tls_require_ciphers", &expciphers,
+ &err))
return US"failed to expand tls_require_ciphers";
if (!(expciphers && *expciphers))
err = NULL;
-ctx = SSL_CTX_new(SSLv23_server_method());
-if (!ctx)
+#ifdef EXIM_HAVE_OPENSSL_TLS_METHOD
+if (!(ctx = SSL_CTX_new(TLS_server_method())))
+#else
+if (!(ctx = SSL_CTX_new(SSLv23_server_method())))
+#endif
{
- ERR_error_string(ERR_get_error(), ssl_errstring);
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
return string_sprintf("SSL_CTX_new() failed: %s", ssl_errstring);
}
if (!SSL_CTX_set_cipher_list(ctx, CS expciphers))
{
- ERR_error_string(ERR_get_error(), ssl_errstring);
- err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed", expciphers);
+ ERR_error_string_n(ERR_get_error(), ssl_errstring, sizeof(ssl_errstring));
+ err = string_sprintf("SSL_CTX_set_cipher_list(%s) failed: %s",
+ expciphers, ssl_errstring);
}
SSL_CTX_free(ctx);
int i, needed_len;
static pid_t pidlast = 0;
pid_t pidnow;
-uschar *p;
uschar smallbuf[sizeof(r)];
if (max <= 1)
gettimeofday(&r.tv, NULL);
r.p = getpid();
- RAND_seed((uschar *)(&r), sizeof(r));
+ RAND_seed(US (&r), sizeof(r));
}
/* We're after pseudo-random, not random; if we still don't have enough data
in the internal PRNG then our options are limited. We could sleep and hope
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)
}
r = 0;
-for (p = smallbuf; needed_len; --needed_len, ++p)
- {
- r *= 256;
- r += *p;
- }
+for (uschar * p = smallbuf; needed_len; --needed_len, ++p)
+ r = 256 * r + *p;
/* We don't particularly care about weighted results; if someone wants
smooth distribution and cares enough then they should submit a patch then. */
Returns success or failure in parsing
*/
-struct exim_openssl_option {
- uschar *name;
- long value;
-};
-/* We could use a macro to expand, but we need the ifdef and not all the
-options document which version they were introduced in. Policylet: include
-all options unless explicitly for DTLS, let the administrator choose which
-to apply.
-
-This list is current as of:
- ==> 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
- { US"all", SSL_OP_ALL },
-#endif
-#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
- { US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION },
-#endif
-#ifdef SSL_OP_CIPHER_SERVER_PREFERENCE
- { US"cipher_server_preference", SSL_OP_CIPHER_SERVER_PREFERENCE },
-#endif
-#ifdef SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
- { US"dont_insert_empty_fragments", SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS },
-#endif
-#ifdef SSL_OP_EPHEMERAL_RSA
- { US"ephemeral_rsa", SSL_OP_EPHEMERAL_RSA },
-#endif
-#ifdef SSL_OP_LEGACY_SERVER_CONNECT
- { US"legacy_server_connect", SSL_OP_LEGACY_SERVER_CONNECT },
-#endif
-#ifdef SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
- { US"microsoft_big_sslv3_buffer", SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER },
-#endif
-#ifdef SSL_OP_MICROSOFT_SESS_ID_BUG
- { US"microsoft_sess_id_bug", SSL_OP_MICROSOFT_SESS_ID_BUG },
-#endif
-#ifdef SSL_OP_MSIE_SSLV2_RSA_PADDING
- { US"msie_sslv2_rsa_padding", SSL_OP_MSIE_SSLV2_RSA_PADDING },
-#endif
-#ifdef SSL_OP_NETSCAPE_CHALLENGE_BUG
- { US"netscape_challenge_bug", SSL_OP_NETSCAPE_CHALLENGE_BUG },
-#endif
-#ifdef SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
- { US"netscape_reuse_cipher_change_bug", SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG },
-#endif
-#ifdef SSL_OP_NO_COMPRESSION
- { US"no_compression", SSL_OP_NO_COMPRESSION },
-#endif
-#ifdef SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
- { US"no_session_resumption_on_renegotiation", SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION },
-#endif
-#ifdef SSL_OP_NO_SSLv2
- { US"no_sslv2", SSL_OP_NO_SSLv2 },
-#endif
-#ifdef SSL_OP_NO_SSLv3
- { US"no_sslv3", SSL_OP_NO_SSLv3 },
-#endif
-#ifdef SSL_OP_NO_TICKET
- { US"no_ticket", SSL_OP_NO_TICKET },
-#endif
-#ifdef SSL_OP_NO_TLSv1
- { US"no_tlsv1", SSL_OP_NO_TLSv1 },
-#endif
-#ifdef SSL_OP_NO_TLSv1_1
-#if SSL_OP_NO_TLSv1_1 == 0x00000400L
- /* Error in chosen value in 1.0.1a; see first item in CHANGES for 1.0.1b */
-#warning OpenSSL 1.0.1a uses a bad value for SSL_OP_NO_TLSv1_1, ignoring
-#else
- { US"no_tlsv1_1", SSL_OP_NO_TLSv1_1 },
-#endif
-#endif
-#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
-#ifdef SSL_OP_SINGLE_ECDH_USE
- { US"single_ecdh_use", SSL_OP_SINGLE_ECDH_USE },
-#endif
-#ifdef SSL_OP_SSLEAY_080_CLIENT_DH_BUG
- { US"ssleay_080_client_dh_bug", SSL_OP_SSLEAY_080_CLIENT_DH_BUG },
-#endif
-#ifdef SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
- { US"sslref2_reuse_cert_type_bug", SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG },
-#endif
-#ifdef SSL_OP_TLS_BLOCK_PADDING_BUG
- { US"tls_block_padding_bug", SSL_OP_TLS_BLOCK_PADDING_BUG },
-#endif
-#ifdef SSL_OP_TLS_D5_BUG
- { US"tls_d5_bug", SSL_OP_TLS_D5_BUG },
-#endif
-#ifdef SSL_OP_TLS_ROLLBACK_BUG
- { US"tls_rollback_bug", SSL_OP_TLS_ROLLBACK_BUG },
-#endif
-};
-static int exim_openssl_options_size =
- sizeof(exim_openssl_options)/sizeof(struct exim_openssl_option);
static BOOL
tls_openssl_options_parse(uschar *option_spec, long *results)
{
long result, item;
-uschar *s, *end;
+uschar * exp, * end;
uschar keep_c;
BOOL adding, item_parsed;
-result = 0L;
+/* Server: send no (<= TLS1.2) session tickets */
+result = SSL_OP_NO_TICKET;
+
/* Prior to 4.80 we or'd in SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS; removed
- * from default because it increases BEAST susceptibility. */
+from default because it increases BEAST susceptibility. */
#ifdef SSL_OP_NO_SSLv2
result |= SSL_OP_NO_SSLv2;
#endif
+#ifdef SSL_OP_NO_SSLv3
+result |= SSL_OP_NO_SSLv3;
+#endif
+#ifdef SSL_OP_SINGLE_DH_USE
+result |= SSL_OP_SINGLE_DH_USE;
+#endif
+#ifdef SSL_OP_NO_RENEGOTIATION
+result |= SSL_OP_NO_RENEGOTIATION;
+#endif
-if (option_spec == NULL)
+if (!option_spec)
{
*results = result;
return TRUE;
}
-for (s=option_spec; *s != '\0'; /**/)
+if (!expand_check(option_spec, US"openssl_options", &exp, &end))
+ return FALSE;
+
+for (uschar * s = exp; *s; /**/)
{
while (isspace(*s)) ++s;
if (*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);
return FALSE;
}
- DEBUG(D_tls) debug_printf("openssl option, %s from %lx: %lx (%s)\n",
- adding ? "adding" : "removing", result, item, s);
+ DEBUG(D_tls) debug_printf("openssl option, %s %08lx: %08lx (%s)\n",
+ adding ? "adding to " : "removing from", result, item, s);
if (adding)
result |= item;
else
result &= ~item;
- *end = keep_c;
s = end;
}
return TRUE;
}
+#endif /*!MACRO_PREDEF*/
/* vi: aw ai sw=2
*/
/* End of tls-openssl.c */
projects / exim.git / blobdiff