1 files changed, 67 insertions, 4 deletions
diff --git a/common/mbox-util.c b/common/mbox-util.c
index c1f05b834..a9086a3f5 100644
--- a/common/mbox-util.c
+++ b/common/mbox-util.c
@@ -173,11 +173,12 @@ is_valid_mailbox (const char *name)
 
 
 /* Return the mailbox (local-part@domain) form a standard user id.
-   All plain ASCII characters in the result are converted to
-   lowercase.  Caller must free the result.  Returns NULL if no valid
-   mailbox was found (or we are out of memory). */
+ * All plain ASCII characters in the result are converted to
+ * lowercase.  If SUBADDRESS is 1, '+' denoted sub-addresses are not
+ * included in the result.  Caller must free the result.  Returns NULL
+ * if no valid mailbox was found (or we are out of memory). */
 char *
-mailbox_from_userid (const char *userid)
+mailbox_from_userid (const char *userid, int subaddress)
 {
   const char *s, *s_end;
   size_t len;
@@ -226,6 +227,29 @@ mailbox_from_userid (const char *userid)
   else
     errno = EINVAL;
 
+  if (result && subaddress == 1)
+    {
+      char *atsign, *plus;
+
+      if ((atsign = strchr (result, '@')))
+        {
+          /* We consider a subaddress only if there is a single '+'
+           * in the local part and the '+' is not the first or last
+           * character.  */
+          *atsign = 0;
+          if ((plus = strchr (result, '+'))
+              && !strchr (plus+1, '+')
+              && result != plus
+              && plus[1] )
+            {
+              *atsign = '@';
+              memmove (plus, atsign, strlen (atsign)+1);
+            }
+          else
+            *atsign = '@';
+        }
+    }
+
   return result? ascii_strlwr (result): NULL;
 }
 
@@ -241,3 +265,42 @@ is_valid_user_id (const char *uid)
 
   return 1;
 }
+
+
+/* Returns true if STRING is a valid domain name according to the LDH
+ * rule. */
+int
+is_valid_domain_name (const char *string)
+{
+  static char const ldh_chars[] =
+    "01234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-";
+  const char *s;
+
+  /* Note that we do not check the length limit of a label or the
+   * entire name */
+
+  for (s=string; *s; s++)
+    if (*s == '.')
+      {
+        if (string == s)
+          return 0; /* Dot at the start of the string.  */
+                    /* (may also be at the end like in ".") */
+        if (s[1] == '.')
+          return 0; /* No - double dot.  */
+      }
+    else if (!strchr (ldh_chars, *s))
+      return 0;
+    else if (*s == '-')
+      {
+        if (string == s)
+          return 0;  /* Leading hyphen.  */
+        if (s[-1] == '.')
+          return 0;  /* Hyphen at begin of a label.  */
+        if (s[1] == '.')
+          return 0;  /* Hyphen at start of a label.  */
+        if (!s[1])
+          return 0;  /* Trailing hyphen.  */
+      }
+
+  return !!*string;
+}