src/src/dane.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) University of Cambridge 1995 - 2012, 2014 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 /* This module provides DANE (RFC6659) support for Exim.  See also
   9 the draft RFC for DANE-over-SMTP, "SMTP security via opportunistic DANE TLS"
  10 (V. Dukhovni, W. Hardaker) - version 10, dated May 25, 2014.
  11
  12 The code for DANE support with Openssl was provided by V.Dukhovni.
  13
  14 No cryptographic code is included in Exim. All this module does is to call
  15 functions from the OpenSSL or GNU TLS libraries. */
  16
  17
  18 #include "exim.h"
  19
  20 /* This module is compiled only when it is specifically requested in the
  21 build-time configuration. However, some compilers don't like compiling empty
  22 modules, so keep them happy with a dummy when skipping the rest. Make it
  23 reference itself to stop picky compilers complaining that it is unused, and put
  24 in a dummy argument to stop even pickier compilers complaining about infinite
  25 loops. */
  26
  27 #ifndef EXPERIMENTAL_DANE
  28 static void dummy(int x) { dummy(x-1); }
  29 #else
  30
  31 /* Enabling DANE without enabling TLS cannot work. Abort the compilation. */
  32 # ifndef SUPPORT_TLS
  33 #  error DANE support requires that TLS support must be enabled. Abort build.
  34 # endif
  35
  36 /* DNSSEC support is also required */
  37 # ifndef RES_USE_DNSSEC
  38 #  error DANE support requires that the DNS reolver library supports DNSSEC
  39 # endif
  40
  41 # ifdef USE_GNUTLS
  42 #  include "dane-gnu.c"
  43 # else
  44 #  include "dane-openssl.c"
  45 # endif
  46
  47
  48 #endif  /* EXPERIMENTAL_DANE */
  49
  50 /* End of dane.c */