DANE: move to mainline

[exim.git] / src / src / tls-openssl.c

diff --git a/src/src/tls-openssl.c b/src/src/tls-openssl.c
index 9816f734f3018a0bcf0638139c759a9dc144d7fa..71d748f5c495fd31a033bf29c53835a184979dcb 100644 (file)
--- a/src/src/tls-openssl.c
+++ b/src/src/tls-openssl.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2017 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Portions Copyright (c) The OpenSSL Project 1999 */
@@ -28,7 +28,7 @@ functions from the OpenSSL library. */
 #ifndef DISABLE_OCSP
 # include <openssl/ocsp.h>
 #endif
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
 # include "danessl.h"
 #endif
 
@@ -51,7 +51,7 @@ functions from the OpenSSL library. */
 # define EXIM_HAVE_RAND_PSEUDO
 #endif
 #if (OPENSSL_VERSION_NUMBER >= 0x0090800fL) && !defined(OPENSSL_NO_SHA256)
-# define EXIM_HAVE_SHA256
+# define EXIM_HAVE_SHA256      /*MMMM*/
 #endif
 
 /*
@@ -81,7 +81,7 @@ functions from the OpenSSL library. */
     || LIBRESSL_VERSION_NUMBER >= 0x20010000L
 # if !defined(OPENSSL_NO_ECDH)
 #  if OPENSSL_VERSION_NUMBER >= 0x0090800fL
-#   define EXIM_HAVE_ECDH
+#   define EXIM_HAVE_ECDH      /*MMMM*/
 #  endif
 #  if OPENSSL_VERSION_NUMBER >= 0x10002000L
 #   define EXIM_HAVE_OPENSSL_EC_NIST2NID
@@ -94,6 +94,10 @@ functions from the OpenSSL library. */
 # define DISABLE_OCSP
 #endif
 
+#ifdef EXIM_HAVE_OPENSSL_CHECKHOST
+# include <openssl/x509v3.h>
+#endif
+
 /* Structure for collecting random data for seeding. */
 
 typedef struct randstuff {
@@ -147,8 +151,8 @@ static BOOL reexpand_tls_files_for_sni = FALSE;
 typedef struct tls_ext_ctx_cb {
   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 {
@@ -508,7 +512,7 @@ return verify_callback(preverify_ok, x509ctx, &tls_in,
 }
 
 
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
 
 /* This gets called *by* the dane library verify callback, which interposes
 itself.
@@ -536,8 +540,21 @@ DEBUG(D_tls) debug_printf("verify_callback_client_dane: %s depth %d %s\n",
 #endif
 
 if (preverify_ok == 1)
-  tls_out.dane_verified =
-  tls_out.certificate_verified = TRUE;
+  {
+  tls_out.dane_verified = tls_out.certificate_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);
@@ -549,7 +566,7 @@ else
 return preverify_ok;
 }
 
-#endif /*EXPERIMENTAL_DANE*/
+#endif /*SUPPORT_DANE*/
 
 
 /*************************************************
@@ -933,7 +950,7 @@ if (!OCSP_check_validity(thisupd, nextupd, EXIM_OCSP_SKEW_SECONDS, EXIM_OCSP_MAX
   }
 
 supply_response:
-  cbinfo->u_ocsp.server.response = resp;
+  cbinfo->u_ocsp.server.response = resp;       /*XXX stack?*/
 return;
 
 bad:
@@ -941,7 +958,7 @@ bad:
     {
     extern char ** environ;
     uschar ** p;
-    if (environ) for (p = USS environ; *p != NULL; p++)
+    if (environ) for (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");
@@ -1130,6 +1147,7 @@ else
 #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;
 
@@ -1267,9 +1285,15 @@ static int
 tls_server_stapling_cb(SSL *s, void *arg)
 {
 const tls_ext_ctx_cb *cbinfo = (tls_ext_ctx_cb *) arg;
-uschar *response_der;
+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");
@@ -1279,7 +1303,7 @@ if (!cbinfo->u_ocsp.server.response)
   return SSL_TLSEXT_ERR_NOACK;
 
 response_der = NULL;
-response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response,
+response_der_len = i2d_OCSP_RESPONSE(cbinfo->u_ocsp.server.response,   /*XXX stack*/
                      &response_der);
 if (response_der_len <= 0)
   return SSL_TLSEXT_ERR_NOACK;
@@ -1353,7 +1377,7 @@ if(!(bs = OCSP_response_get1_basic(rsp)))
     int status, reason;
     ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
 
-    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 */
 
@@ -1364,10 +1388,12 @@ if(!(bs = OCSP_response_get1_basic(rsp)))
              cbinfo->u_ocsp.client.verify_store, 0)) <= 0)
       {
       tls_out.ocsp = OCSP_FAILED;
-      if (LOGGING(tls_cipher))
-       log_write(0, LOG_MAIN, "Received TLS cert status response, itself unverifiable");
+      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;
       }
 
@@ -1471,7 +1497,7 @@ static int
 tls_init(SSL_CTX **ctxp, host_item *host, uschar *dhparam, uschar *certificate,
   uschar *privatekey,
 #ifndef DISABLE_OCSP
-  uschar *ocsp_file,
+  uschar *ocsp_file,   /*XXX stack, in server*/
 #endif
   address_item *addr, tls_ext_ctx_cb ** cbp, uschar ** errstr)
 {
@@ -1483,9 +1509,10 @@ tls_ext_ctx_cb * cbinfo;
 cbinfo = store_malloc(sizeof(tls_ext_ctx_cb));
 cbinfo->certificate = certificate;
 cbinfo->privatekey = privatekey;
+cbinfo->is_server = host==NULL;
 #ifndef DISABLE_OCSP
 cbinfo->verify_stack = NULL;
-if ((cbinfo->is_server = host==NULL))
+if (!host)
   {
   cbinfo->u_ocsp.server.file = ocsp_file;
   cbinfo->u_ocsp.server.file_expanded = NULL;
@@ -1798,7 +1825,7 @@ if (expcerts && *expcerts)
           )
          {
          log_write(0, LOG_MAIN|LOG_PANIC,
-           "failed to load cert hain from %s", file);
+           "failed to load cert chain from %s", file);
          return DEFER;
          }
 #endif
@@ -1941,7 +1968,7 @@ the error. */
 
 rc = tls_init(&server_ctx, NULL, tls_dhparam, tls_certificate, tls_privatekey,
 #ifndef DISABLE_OCSP
-    tls_ocsp_file,
+    tls_ocsp_file,     /*XXX stack*/
 #endif
     NULL, &server_static_cbinfo, errstr);
 if (rc != OK) return rc;
@@ -1969,7 +1996,7 @@ if (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;
@@ -2128,7 +2155,7 @@ return OK;
 }
 
 
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
 static int
 dane_tlsa_load(SSL * ssl, host_item * host, dns_answer * dnsa, uschar ** errstr)
 {
@@ -2183,7 +2210,7 @@ if (found)
 log_write(0, LOG_MAIN, "DANE error: No usable TLSA records");
 return DEFER;
 }
-#endif /*EXPERIMENTAL_DANE*/
+#endif /*SUPPORT_DANE*/
 
 
 
@@ -2209,7 +2236,7 @@ Returns:           OK on success
 int
 tls_client_start(int fd, host_item *host, address_item *addr,
   transport_instance * tb,
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
   dns_answer * tlsa_dnsa,
 #endif
   uschar ** errstr)
@@ -2226,13 +2253,13 @@ BOOL request_ocsp = FALSE;
 BOOL require_ocsp = FALSE;
 #endif
 
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
 tls_out.tlsa_usage = 0;
 #endif
 
 #ifndef DISABLE_OCSP
   {
-# ifdef EXPERIMENTAL_DANE
+# ifdef SUPPORT_DANE
   if (  tlsa_dnsa
      && ob->hosts_request_ocsp[0] == '*'
      && ob->hosts_request_ocsp[1] == '\0'
@@ -2250,7 +2277,7 @@ tls_out.tlsa_usage = 0;
        verify_check_given_host(&ob->hosts_require_ocsp, host) == OK))
     request_ocsp = TRUE;
   else
-# ifdef EXPERIMENTAL_DANE
+# ifdef SUPPORT_DANE
     if (!request_ocsp)
 # endif
       request_ocsp =
@@ -2286,7 +2313,7 @@ if (expciphers)
     return tls_error(US"SSL_CTX_set_cipher_list", host, NULL, errstr);
   }
 
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
 if (tlsa_dnsa)
   {
   SSL_CTX_set_verify(client_ctx,
@@ -2334,7 +2361,7 @@ if (ob->tls_sni)
     }
   }
 
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
 if (tlsa_dnsa)
   if ((rc = dane_tlsa_load(client_ssl, host, tlsa_dnsa, errstr)) != OK)
     return rc;
@@ -2343,7 +2370,7 @@ if (tlsa_dnsa)
 #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;
@@ -2380,7 +2407,7 @@ alarm(ob->command_timeout);
 rc = SSL_connect(client_ssl);
 alarm(0);
 
-#ifdef EXPERIMENTAL_DANE
+#ifdef SUPPORT_DANE
 if (tlsa_dnsa)
   DANESSL_cleanup(client_ssl);
 #endif