2009-02-23 Mark Probst <mark.probst@gmail.com>

[mono.git] / mono / utils / strenc.c

diff --git a/mono/utils/strenc.c b/mono/utils/strenc.c
index c37bb3d20168ffb6c93473b33ce7558b4da2ffb7..fe8ba8ae15c48c2db24c3f6250dccf352bbb02fb 100644 (file)
--- a/mono/utils/strenc.c
+++ b/mono/utils/strenc.c
@@ -15,6 +15,17 @@
 
 #undef DEBUG
 
+static const char trailingBytesForUTF8[256] = {
+       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+       0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+       1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
+       2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,0,0
+};
+
 /**
  * mono_unicode_from_external:
  * @in: pointers to the buffer.
@@ -214,3 +225,70 @@ gchar *mono_unicode_to_external (const gunichar2 *uni)
        return(utf8);
 }
 
+/**
+ * mono_utf8_validate_and_len
+ * @source: Pointer to putative UTF-8 encoded string.
+ *
+ * Checks @source for being valid UTF-8. @utf is assumed to be
+ * null-terminated.
+ *
+ * Return value: true if @source is valid.
+ * oEnd : will equal the null terminator at the end of the string if valid.
+ *            if not valid, it will equal the first charater of the invalid sequence.
+ * oLengh : will equal the length to @oEnd
+ **/
+gboolean
+mono_utf8_validate_and_len (const gchar *source, glong* oLength, const gchar** oEnd)
+{
+       gboolean retVal = TRUE;
+       gboolean lastRet = TRUE;
+       guchar* ptr = (guchar*) source;
+       guchar* srcPtr;
+       guint length;
+       guchar a;
+       *oLength = 0;
+       while (*ptr != 0) {
+               length = trailingBytesForUTF8 [*ptr] + 1;
+               srcPtr = (guchar*) ptr + length;
+               switch (length) {
+               default: retVal = FALSE;
+               /* Everything else falls through when "TRUE"... */
+               case 4: if ((a = (*--srcPtr)) < (guchar) 0x80 || a > (guchar) 0xBF) retVal = FALSE;
+                               if ((a == (guchar) 0xBF || a == (guchar) 0xBE) && *(srcPtr-1) == (guchar) 0xBF) {
+                               if (*(srcPtr-2) == (guchar) 0x8F || *(srcPtr-2) == (guchar) 0x9F ||
+                                       *(srcPtr-2) == (guchar) 0xAF || *(srcPtr-2) == (guchar) 0xBF)
+                                       retVal = FALSE;
+                               }
+               case 3: if ((a = (*--srcPtr)) < (guchar) 0x80 || a > (guchar) 0xBF) retVal = FALSE;
+               case 2: if ((a = (*--srcPtr)) < (guchar) 0x80 || a > (guchar) 0xBF) retVal = FALSE;
+
+               switch (*ptr) {
+               /* no fall-through in this inner switch */
+               case 0xE0: if (a < (guchar) 0xA0) retVal = FALSE; break;
+               case 0xED: if (a > (guchar) 0x9F) retVal = FALSE; break;
+               case 0xEF: if (a == (guchar)0xB7 && (*(srcPtr+1) > (guchar) 0x8F && *(srcPtr+1) < 0xB0)) retVal = FALSE;
+                                  if (a == (guchar)0xBF && (*(srcPtr+1) == (guchar) 0xBE || *(srcPtr+1) == 0xBF)) retVal = FALSE; break;
+               case 0xF0: if (a < (guchar) 0x90) retVal = FALSE; break;
+               case 0xF4: if (a > (guchar) 0x8F) retVal = FALSE; break;
+               default:   if (a < (guchar) 0x80) retVal = FALSE;
+               }
+
+               case 1: if (*ptr >= (guchar ) 0x80 && *ptr < (guchar) 0xC2) retVal = FALSE;
+               }
+               if (*ptr > (guchar) 0xF4)
+                       retVal = FALSE;
+               //If the string is invalid, set the end to the invalid byte.
+               if (!retVal && lastRet) {
+                       if (oEnd != NULL)
+                               *oEnd = (gchar*) ptr;
+                       lastRet = FALSE;
+               }
+               ptr += length;
+               (*oLength)++;
+       }
+       if (retVal && oEnd != NULL)
+               *oEnd = (gchar*) ptr;
+       return retVal;
+}
+
+