IDN support for e-mail messages. Things should work automagically

once you have the GNU IDN library available from
ftp://alpha.gnu.org/pub/gnu/libidn/ installed.  For IDN's which
can't be losslessly recoded to your local character set, mutt should
automatically fall back to using the ASCII representation.  There's
probably a considerable number of bugs in this, and the code may, at
this point, not even compile on machines without libidn.  Will start
working on that ASAP.

1 files changed, 253 insertions, 0 deletions

diff --git a/mutt_idna.c b/mutt_idna.c
new file mode 100644
index 00000000..2d3f4c4f
--- /dev/null
+++ b/mutt_idna.c
@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2003 Thomas Roessler <roessler@does-not-exist.org>
+ * 
+ *     This program is free software; you can redistribute it and/or modify
+ *     it under the terms of the GNU General Public License as published by
+ *     the Free Software Foundation; either version 2 of the License, or
+ *     (at your option) any later version.
+ * 
+ *     This program is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ * 
+ *     You should have received a copy of the GNU General Public License
+ *     along with this program; if not, write to the Free Software
+ *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ */ 
+
+#include "config.h"
+#include "mutt.h"
+#include "charset.h"
+#include "mutt_idna.h"
+
+/* The low-level interface we use. */
+
+#ifndef HAVE_LIBIDN
+
+int mutt_idna_to_local (const char *in, char **out, int flags)
+{
+  *out = safe_strdup (in);
+  return 1;
+}
+
+int mutt_local_to_idna (const char *in, char **out)
+{
+  *out = safe_strdup (in);
+  return 0;
+}
+			
+#else
+
+int mutt_idna_to_local (const char *in, char **out, int flags)
+{
+  *out = NULL;
+
+  /* Is this the right function?  Interesting effects with some bad identifiers! */
+  if (idna_to_unicode_utf8_from_utf8 (in, out, 0, 1) != IDNA_SUCCESS)
+    goto notrans;
+  if (mutt_convert_string (out, "utf-8", Charset, M_ICONV_HOOK_TO) == -1)
+    goto notrans;
+
+  /* 
+   * make sure that we can convert back and come out with the same
+   * domain name. */
+  
+  if ((flags & MI_MAY_BE_IRREVERSIBLE) == 0)
+  {
+    int irrev = 0;
+    char *t2 = NULL;
+    char *tmp = safe_strdup (*out);
+    if (mutt_convert_string (&tmp, Charset, "utf-8", M_ICONV_HOOK_FROM) == -1)
+      irrev = 1;
+    if (!irrev && idna_to_ascii_from_utf8 (tmp, &t2, 0, 1) != IDNA_SUCCESS)
+      irrev = 1;
+    if (!irrev && ascii_strcasecmp (t2, in))
+    {
+      dprint (1, (debugfile, "mutt_idna_to_local: Not reversible. in = '%s', t2 = '%s'.\n",
+		  in, t2));
+      irrev = 1;
+    }
+    
+    FREE (&t2);
+    FREE (&tmp);
+
+    if (irrev)
+      goto notrans;
+  }
+
+  return 0;
+  
+ notrans:
+  FREE (out);
+  *out = safe_strdup (in);
+  return 1;
+}
+
+int mutt_local_to_idna (const char *in, char **out)
+{
+  int rv = 0;
+  char *tmp = safe_strdup (in);
+  *out = NULL;
+
+  if (mutt_convert_string (&tmp, Charset, "utf-8", M_ICONV_HOOK_FROM) == -1)
+    rv = -1;
+  if (!rv && idna_to_ascii_from_utf8 (tmp, out, 0, 1) != IDNA_SUCCESS)
+    rv = -2;
+  
+  FREE (&tmp);
+  if (rv < 0)
+  {
+    FREE (out);
+    *out = safe_strdup (in);
+  }
+  return rv;
+}
+
+#endif
+
+
+/* higher level functions */
+
+static int mbox_to_udomain (const char *mbx, char **user, char **domain)
+{
+  char *scratch = safe_strdup (mbx);
+  *user = NULL;
+  *domain = NULL;
+  
+  if ((*domain = strchr (scratch, '@')) == NULL)
+    return -1;
+  
+  **domain = '\0';
+  *domain = safe_strdup (*domain + 1);
+  *user = scratch;
+  return 0;
+}
+
+int mutt_addrlist_to_idna (ADDRESS *a, char **err)
+{
+  char *user = NULL, *domain = NULL;
+  char *tmp = NULL;
+  int e = 0;
+  
+  if (err)
+    *err = NULL;
+
+  for (; a; a = a->next)
+  {
+    if (!a->mailbox)
+      continue;
+    if (mbox_to_udomain (a->mailbox, &user, &domain) == -1)
+      continue;
+    
+    if (mutt_local_to_idna (domain, &tmp) < 0)
+    {
+      e = 1;
+      if (err)
+	*err = safe_strdup (domain);
+    }
+    else
+    {
+      safe_realloc ((void **) &a->mailbox, mutt_strlen (user) + mutt_strlen (tmp) + 2);
+      sprintf (a->mailbox, "%s@%s", NONULL(user), NONULL(tmp)); /* __SPRINTF_CHECKED__ */
+    }
+    
+    FREE (&domain);
+    FREE (&user);
+    FREE (&tmp);
+    
+    if (e)
+      return -1;
+  }
+  
+  return 0;
+}
+
+int mutt_addrlist_to_local (ADDRESS *a)
+{
+  char *user, *domain;
+  char *tmp = NULL;
+  
+  for (; a; a = a->next)
+  {
+    if (!a->mailbox)
+      continue;
+    if (mbox_to_udomain (a->mailbox, &user, &domain) == -1)
+      continue;
+    
+    if (mutt_idna_to_local (domain, &tmp, 0) == 0)
+    {
+      safe_realloc ((void **) &a->mailbox, mutt_strlen (user) + mutt_strlen (tmp) + 2);
+      sprintf (a->mailbox, "%s@%s", NONULL (user), NONULL (tmp)); /* __SPRINTF_CHECKED__ */
+    }
+    
+    FREE (&domain);
+    FREE (&user);
+    FREE (&tmp);
+  }
+  
+  return 0;
+}
+
+/* convert just for displaying purposes */
+const char *mutt_addr_for_display (ADDRESS *a)
+{
+  static char *buff = NULL;
+  char *tmp = NULL;
+  char *domain, *user;
+  
+  FREE (&buff);
+  
+  if (mbox_to_udomain (a->mailbox, &user, &domain) != 0)
+    return a->mailbox;
+  if (mutt_idna_to_local (domain, &tmp, MI_MAY_BE_IRREVERSIBLE) != 0)
+  {
+    FREE (&tmp);
+    return a->mailbox;
+  }
+  
+  safe_realloc ((void **) &buff, mutt_strlen (tmp) + mutt_strlen (user) + 2);
+  sprintf (buff, "%s@%s", NONULL(user), NONULL(tmp)); /* __SPRINTF_CHECKED__ */
+  FREE (&tmp);
+  return buff;
+}
+
+/* Convert an ENVELOPE structure */
+
+void mutt_env_to_local (ENVELOPE *e)
+{
+  mutt_addrlist_to_local (e->return_path);
+  mutt_addrlist_to_local (e->from);
+  mutt_addrlist_to_local (e->to);
+  mutt_addrlist_to_local (e->cc);
+  mutt_addrlist_to_local (e->bcc);
+  mutt_addrlist_to_local (e->reply_to);
+  mutt_addrlist_to_local (e->mail_followup_to);
+}
+
+/* 
+ * XXX -- this macro produces warnings, but yields the right kind
+ * of code when preprocessed. How to fix this *without* typing the same
+ * code all over the place?
+ */
+
+#define H_TO_IDNA(a)	\
+  if (mutt_addrlist_to_idna (env->##a, err) && !e) \
+  { \
+     if (tag) *tag = #a; e = 1; err = NULL; \
+  }
+
+int mutt_env_to_idna (ENVELOPE *env, char **tag, char **err)
+{
+  int e = 0;
+  H_TO_IDNA(return_path);
+  H_TO_IDNA(from);
+  H_TO_IDNA(to);
+  H_TO_IDNA(cc);
+  H_TO_IDNA(bcc);
+  H_TO_IDNA(reply_to);
+  H_TO_IDNA(mail_followup_to);
+  return e;
+}
+
+#undef H_TO_IDNA