* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) University of Cambridge 1995 - 2019 */
/* See the file NOTICE for conditions of use and distribution. */
/* Portions Copyright (c) The OpenSSL Project 1999 */
# 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
# else
# define EXIM_NEED_OPENSSL_INIT
# endif
# 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_GET_ID
# define SSL_CIPHER_get_id(c) (c->id)
# endif
-# include "tls-cipher-stdname.c"
+# ifndef MACRO_PREDEF
+# include "tls-cipher-stdname.c"
+# endif
#endif
/*************************************************
static exim_openssl_option exim_openssl_options[] = {
/* KEEP SORTED ALPHABETICALLY! */
#ifdef SSL_OP_ALL
- { US"all", SSL_OP_ALL },
+ { US"all", (long) SSL_OP_ALL },
#endif
#ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
{ US"allow_unsafe_legacy_renegotiation", SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION },
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
}
#else
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;
BOOL is_server;
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 */
/* 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
#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 *
*************************************************/
}
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;
}
dn[sizeof(dn)-1] = '\0';
+tlsp->verify_override = FALSE;
if (preverify_ok == 0)
{
uschar * extra = verify_mode ? string_sprintf(" (during %c-verify for [%s])",
}
DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
"tls_try_verify_hosts)\n");
+ tlsp->verify_override = TRUE;
}
else if (depth != 0)
tlsp->peercert = X509_dup(cert); /* record failing cert */
return 0; /* reject */
}
- DEBUG(D_tls) debug_printf("SSL verify failure overridden (host in "
+ DEBUG(D_tls) debug_printf("SSL verify name failure overridden (host in "
"tls_try_verify_hosts)\n");
+ tlsp->verify_override = TRUE;
}
}
DEBUG(D_tls) debug_printf("SSL%s verify ok: depth=0 SN=%s\n",
*calledp ? "" : " authenticated", dn);
- if (!*calledp) tlsp->certificate_verified = TRUE;
*calledp = TRUE;
}
if (preverify_ok == 1)
{
- tls_out.dane_verified = tls_out.certificate_verified = TRUE;
+ tls_out.dane_verified = TRUE;
#ifndef DISABLE_OCSP
if (client_static_cbinfo->u_ocsp.client.verify_store)
{ /* client, wanting stapling */
#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 exim_stek *
+tk_find(const uschar * name)
+{
+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
+ticket_key_callback(SSL * ssl, uschar key_name[16],
+ uschar * iv, EVP_CIPHER_CTX * ctx, HMAC_CTX * hctx, int enc)
+{
+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;
+
+ if (RAND_bytes(iv, EVP_MAX_IV_LENGTH) <= 0)
+ return -1; /* insufficient random */
+
+ 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);
+
+ DEBUG(D_tls) debug_printf("ticket created\n");
+ return 1;
+ }
+else
+ {
+ time_t now = time(NULL);
+
+ DEBUG(D_tls) debug_printf("ticket_key_callback: retrieve session\n");
+ tlsp->resumption |= RESUME_CLIENT_SUGGESTED;
+
+ if (!(key = tk_find(key_name)) || key->expire < now)
+ {
+ DEBUG(D_tls)
+ {
+ 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;
+ }
+
+ 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);
+
+ DEBUG(D_tls) debug_printf("ticket usable, STEK expire " TIME_T_FMT "\n", key->expire - now);
+
+ /* 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
+
+
/*************************************************
* Initialize for DH *
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
*/
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)
{
BIO * bio;
OCSP_RESPONSE * resp;
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'\n", filename);
-if (!(bio = BIO_new_file(CS cbinfo->u_ocsp.server.file_expanded, "rb")))
+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;
}
goto bad;
}
+#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)
(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. */
+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)))
{
}
supply_response:
- cbinfo->u_ocsp.server.response = resp; /*XXX stack?*/
+ /* 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:
}
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*/
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);
+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),
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);
+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);
*/
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;
+uschar * expanded;
if (!cbinfo->certificate)
{
{
int err;
- if (Ustrstr(cbinfo->certificate, US"tls_sni") ||
- Ustrstr(cbinfo->certificate, US"tls_in_sni") ||
- Ustrstr(cbinfo->certificate, US"tls_out_sni")
- )
+ 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 (!expand_check(cbinfo->certificate, US"tls_certificate", &expanded, errstr))
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;
+
+ 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 (olist)
+ if ((ofile = string_nextinlist(&olist, &osep, NULL, 0)))
+ ocsp_load_response(sctx, cbinfo, ofile);
+ 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;
}
-#ifndef DISABLE_OCSP
-if (cbinfo->is_server && cbinfo->u_ocsp.server.file)
- {
- /*XXX stack*/
- if (!expand_check(cbinfo->u_ocsp.server.file, US"tls_ocsp_file", &expanded, errstr))
- return DEFER;
-
- if (expanded && *expanded)
- {
- DEBUG(D_tls) debug_printf("tls_ocsp_file %s\n", expanded);
- if ( cbinfo->u_ocsp.server.file_expanded
- && (Ustrcmp(expanded, cbinfo->u_ocsp.server.file_expanded) == 0))
- {
- DEBUG(D_tls) debug_printf(" - value unchanged, using existing values\n");
- }
- else
- ocsp_load_response(sctx, cbinfo, expanded);
- }
- }
-#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
/* 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)
static int
tls_server_stapling_cb(SSL *s, void *arg)
{
-const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
-uschar *response_der; /*XXX blob */
+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;
-/*XXX stack: use SSL_get_certificate() to see which cert; from that work
-out which ocsp blob to send. Unfortunately, SSL_get_certificate is known
-buggy in current OpenSSL; it returns the last cert loaded always rather than
-the one actually presented. So we can't support a stack of OCSP proofs at
-this time. */
-
DEBUG(D_tls)
- debug_printf("Received TLS status request (OCSP stapling); %s response\n",
- 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, /*XXX stack*/
- &response_der);
+response_der_len = i2d_OCSP_RESPONSE(olist->resp, &response_der);
if (response_der_len <= 0)
return SSL_TLSEXT_ERR_NOACK;
return cbinfo->u_ocsp.client.verify_required ? 0 : 1;
}
-if(!(rsp = d2i_OCSP_RESPONSE(NULL, &p, len)))
- {
- tls_out.ocsp = OCSP_FAILED;
+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 (LOGGING(tls_cipher))
tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate,
uschar *privatekey,
#ifndef DISABLE_OCSP
- uschar *ocsp_file, /*XXX stack, in server*/
+ uschar *ocsp_file,
#endif
- address_item *addr, tls_ext_ctx_cb ** cbp, uschar ** errstr)
+ address_item *addr, tls_ext_ctx_cb ** cbp,
+ tls_support * tlsp,
+ uschar ** errstr)
{
SSL_CTX * ctx;
long init_options;
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;
{
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;
/* Set up the information callback, which outputs if debugging is at a suitable
level. */
-DEBUG(D_tls) SSL_CTX_set_info_callback(ctx, (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
-DEBUG(D_tls) SSL_CTX_set_keylog_callback(ctx, (void (*)())keylog_callback);
+ SSL_CTX_set_keylog_callback(ctx, (void (*)())keylog_callback);
#endif
+ }
/* Automatically re-try reads/writes after renegotiation. */
(void) SSL_CTX_set_mode(ctx, SSL_MODE_AUTO_RETRY);
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(ctx, init_options)))
return tls_error(string_sprintf(
else
DEBUG(D_tls) debug_printf("no SSL CTX options to set\n");
-#ifdef OPENSSL_HAVE_NUM_TICKETS
-SSL_CTX_set_num_tickets(ctx, 0); /* send no TLS1.3 stateful-tickets */
-#endif
-
/* 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.
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. */
SSL_CTX_set_tmp_rsa_callback(ctx, rsa_callback);
#endif
-/* 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(ctx, ssl_session_timeout);
DEBUG(D_tls) debug_printf("Initialized TLS\n");
{ DEBUG(D_tls) debug_printf("X509_NAME_oneline() error\n"); }
else
{
- peerdn[siz-1] = '\0';
- tlsp->peerdn = peerdn; /*XXX a static buffer... */
+ 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 = SSL_get_verify_result(ssl) == X509_V_OK;
}
}
/* 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
rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey,
#ifndef DISABLE_OCSP
- tls_ocsp_file, /*XXX stack*/
+ tls_ocsp_file,
#endif
- NULL, &server_static_cbinfo, errstr);
+ NULL, &server_static_cbinfo, &tls_in, errstr);
if (rc != OK) return rc;
cbinfo = server_static_cbinfo;
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, errstr);
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)))
if (rc <= 0)
{
- (void) tls_error(US"SSL_accept", NULL, sigalrm_seen ? US"timed out" : NULL, errstr);
- 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:
+ (void) tls_error(US"SSL_accept", 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 negociated. */
+ 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. */
#ifdef EXIM_HAVE_OPENSSL_KEYLOG
{
- BIO * bp = BIO_new(BIO_s_mem());
- uschar * s;
- int len;
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
SSL_SESSION_print_keylog(bp, SSL_get_session(server_ssl));
- len = (int) BIO_get_mem_data(bp, CSS &s);
- debug_printf("%.*s", len, s);
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 */
+#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_RDONLY, &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;
+}
+
+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 */
+
+
/*************************************************
* Start a TLS session in a client *
*************************************************/
rc = store_pool;
store_pool = POOL_PERM;
-exim_client_ctx = store_get(sizeof(exim_openssl_client_tls_ctx));
+exim_client_ctx = store_get(sizeof(exim_openssl_client_tls_ctx), FALSE);
exim_client_ctx->corked = NULL;
store_pool = rc;
#ifndef DISABLE_OCSP
(void *)(long)request_ocsp,
#endif
- cookie, &client_static_cbinfo, errstr);
+ cookie, &client_static_cbinfo, tlsp, errstr);
if (rc != OK) return FALSE;
tlsp->certificate_verified = FALSE;
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));
+
SSL_set_fd(exim_client_ctx->ssl, cctx->sock);
SSL_set_connect_state(exim_client_ctx->ssl);
}
#endif
+#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
debug_printf("SSL_connect succeeded\n");
#ifdef EXIM_HAVE_OPENSSL_KEYLOG
{
- BIO * bp = BIO_new(BIO_s_mem());
- if (bp)
- {
- uschar * s;
- int len;
- SSL_SESSION_print_keylog(bp, SSL_get_session(exim_client_ctx->ssl));
- len = (int) BIO_get_mem_data(bp, CSS &s);
- debug_printf("%.*s", len, s);
- BIO_free(bp);
- }
- else
- debug_printf("(alloc failure for keylog)\n");
+ BIO * bp = BIO_new_fp(debug_file, BIO_NOCLOSE);
+ SSL_SESSION_print_keylog(bp, SSL_get_session(exim_client_ctx->ssl));
+ BIO_free(bp);
}
#endif
}
+#ifdef EXPERIMENTAL_TLS_RESUME
+tls_client_resume_posthandshake(exim_client_ctx, tlsp);
+#endif
+
peer_cert(exim_client_ctx->ssl, tlsp, peerdn, sizeof(peerdn));
tlsp->cipher = construct_cipher_name(exim_client_ctx->ssl, &tlsp->bits);
case SSL_ERROR_ZERO_RETURN:
DEBUG(D_tls) debug_printf("Got SSL_ERROR_ZERO_RETURN\n");
- receive_getc = smtp_getc;
- receive_getbuf = smtp_getbuf;
- receive_get_cache = smtp_get_cache;
- receive_ungetc = smtp_ungetc;
- receive_feof = smtp_feof;
- receive_ferror = smtp_ferror;
- receive_smtp_buffered = smtp_buffered;
-
if (SSL_get_shutdown(server_ssl) == SSL_RECEIVED_SHUTDOWN)
SSL_shutdown(server_ssl);
-#ifndef DISABLE_OCSP
- sk_X509_pop_free(server_static_cbinfo->verify_stack, X509_free);
- server_static_cbinfo->verify_stack = NULL;
-#endif
- SSL_free(server_ssl);
- SSL_CTX_free(server_ctx);
- server_ctx = NULL;
- server_ssl = NULL;
- tls_in.active.sock = -1;
- tls_in.active.tls_ctx = NULL;
- tls_in.bits = 0;
- tls_in.cipher = NULL;
- tls_in.peerdn = NULL;
- tls_in.sni = NULL;
-
+ tls_close(NULL, TLS_NO_SHUTDOWN);
return FALSE;
/* Handle genuine errors */
if ((more || corked))
{
-#ifdef EXPERIMENTAL_PIPE_CONNECT
+#ifdef SUPPORT_PIPE_CONNECT
int save_pool = store_pool;
store_pool = POOL_PERM;
#endif
corked = string_catn(corked, buff, len);
-#ifdef EXPERIMENTAL_PIPE_CONNECT
+#ifdef SUPPORT_PIPE_CONNECT
store_pool = save_pool;
#endif
}
}
-#ifndef DISABLE_OCSP
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;
uschar keep_c;
BOOL adding, item_parsed;
+/* 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. */
#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
return TRUE;
}
-for (uschar * s = option_spec; *s != '\0'; /**/)
+for (uschar * s = option_spec; *s; /**/)
{
while (isspace(*s)) ++s;
if (*s == '\0')
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 %8lx: %lx (%s)\n",
+ adding ? "adding to " : "removing from", result, item, s);
if (adding)
result |= item;
else
projects / exim.git / blobdiff