-adding libidn--towards fixing #2475

5 files changed, 70 insertions, 1 deletions

diff --git a/configure.ac b/configure.ac
index 0bedbaca9..28a23f8f0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -370,6 +370,32 @@ then
 else
         AM_CONDITIONAL(HAVE_LIBCURL, false)
 fi
+
+
+# libidn
+AC_MSG_CHECKING([if Libidn can be used])
+AC_ARG_WITH(libidn, AC_HELP_STRING([--with-libidn=[DIR]],
+                                    [Support IDN (needs GNU Libidn)]),
+libidn=$withval, libidn=yes)
+if test "$libidn" != "no"; then
+  if test "$libidn" != "yes"; then
+     LDFLAGS="${LDFLAGS} -L$libidn/lib"
+     CPPFLAGS="${CPPFLAGS} -I$libidn/include"
+  fi
+  AC_CHECK_HEADER(idna.h,
+  AC_CHECK_LIB(idn, stringprep_check_version,
+    [libidn=yes LIBS="${LIBS} -lidn"], libidn=no),
+     libidn=no)
+fi
+if test "$libidn" != "no" ; then
+  AC_DEFINE(LIBIDN, 1, [Define to 1 if you want IDN support.])
+  else
+  AC_MSG_FAILURE([Libidn not found])
+fi
+AC_MSG_RESULT($libidn)
+
+
+
 # restore LIBS
 LIBS=$SAVE_LIBS
 
diff --git a/src/dns/Makefile.am b/src/dns/Makefile.am
index 6e543e07f..42d0c5bd1 100644
--- a/src/dns/Makefile.am
+++ b/src/dns/Makefile.am
@@ -83,7 +83,8 @@ gnunet_service_dns_DEPENDENCIES = \
 libgnunetdnsparser_la_SOURCES = \
  dnsparser.c 
 libgnunetdnsparser_la_LIBADD = \
- $(top_builddir)/src/util/libgnunetutil.la $(XLIB)
+ $(top_builddir)/src/util/libgnunetutil.la $(XLIB) \
+  -lidn
 libgnunetdnsparser_la_LDFLAGS = \
   $(GN_LIB_LDFLAGS) \
   -version-info 0:0:0
diff --git a/src/dns/dnsparser.c b/src/dns/dnsparser.c
index 4b0c03a77..c61c78164 100644
--- a/src/dns/dnsparser.c
+++ b/src/dns/dnsparser.c
@@ -25,11 +25,39 @@
  * @author Christian Grothoff
  */
 #include "platform.h"
+#include <idna.h>
+#if WINDOWS
+#include <idn-free.h>
+#endif
 #include "gnunet_util_lib.h"
 #include "gnunet_dnsparser_lib.h"
 #include "dnsparser.h"
 
 
+/**
+ * Check if a label in UTF-8 format can be coded into valid IDNA.
+ * This can fail if the ASCII-conversion becomes longer than 63 characters.
+ *
+ * @param label label to check (UTF-8 string)
+ * @return GNUNET_OK if the label can be converted to IDNA,
+ *         GNUNET_SYSERR if the label is not valid for DNS names
+ */
+int
+GNUNET_DNSPARSER_check_label (const char *label)
+{
+  char *output;
+  
+  if (IDNA_SUCCESS != 
+      idna_to_ascii_8z (label, &output, IDNA_USE_STD3_ASCII_RULES))
+    return GNUNET_SYSERR;
+#if WINDOWS
+  idn_free (output);
+#else
+  free (output);
+#endif
+  return GNUNET_OK;
+}
+
 
 /**
  * Parse name inside of a DNS query or record.
diff --git a/src/include/gnunet_dnsparser_lib.h b/src/include/gnunet_dnsparser_lib.h
index 328a2286a..19148bd3d 100644
--- a/src/include/gnunet_dnsparser_lib.h
+++ b/src/include/gnunet_dnsparser_lib.h
@@ -479,6 +479,18 @@ struct GNUNET_DNSPARSER_Packet
 
 
 /**
+ * Check if a label in UTF-8 format can be coded into valid IDNA.
+ * This can fail if the ASCII-conversion becomes longer than 63 characters.
+ *
+ * @param label label to check (UTF-8 string)
+ * @return GNUNET_OK if the label can be converted to IDNA,
+ *         GNUNET_SYSERR if the label is not valid for DNS names
+ */
+int
+GNUNET_DNSPARSER_check_label (const char *label);
+
+
+/**
  * Parse a UDP payload of a DNS packet in to a nice struct for further
  * processing and manipulation.
  *
diff --git a/src/include/gnunet_gns_service.h b/src/include/gnunet_gns_service.h
index 3e3d140b9..ac9e2d006 100644
--- a/src/include/gnunet_gns_service.h
+++ b/src/include/gnunet_gns_service.h
@@ -109,6 +109,8 @@ enum GNUNET_GNS_RecordType
 
   /* struct vpn_data */
   GNUNET_GNS_RECORD_VPN  = GNUNET_NAMESTORE_TYPE_VPN,
+
+  /* revocation */
   GNUNET_GNS_RECORD_REV  = GNUNET_NAMESTORE_TYPE_REV
 };