From 8c3e4f19001300c07cb076353eba625e4729fdd2 Mon Sep 17 00:00:00 2001
From: Fabian Keil <fk@fabiankeil.de>
Date: Sun, 6 Nov 2011 11:41:05 +0000
Subject: [PATCH] Add url_requires_percent_encoding()

Checks if an URL contains invalid characters according
to RFC 3986 that should be percent-encoded.
---
 urlmatch.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++-
 urlmatch.h |  6 ++++--
 2 files changed, 52 insertions(+), 3 deletions(-)

diff --git a/urlmatch.c b/urlmatch.c
index 3dead33b..5fe605c1 100644
--- a/urlmatch.c
+++ b/urlmatch.c
@@ -1,4 +1,4 @@
-const char urlmatch_rcs[] = "$Id: urlmatch.c,v 1.62 2011/09/04 11:10:56 fabiankeil Exp $";
+const char urlmatch_rcs[] = "$Id: urlmatch.c,v 1.63 2011/09/04 11:37:05 fabiankeil Exp $";
 /*********************************************************************
  *
  * File        :  $Source: /cvsroot/ijbswa/current/urlmatch.c,v $
@@ -167,6 +167,53 @@ jb_err init_domain_components(struct http_request *http)
 #endif /* ndef FEATURE_EXTENDED_HOST_PATTERNS */
 
 
+/*********************************************************************
+ *
+ * Function    :  url_requires_percent_encoding
+ *
+ * Description :  Checks if an URL contains invalid characters
+ *                according to RFC 3986 that should be percent-encoded.
+ *                Does not verify whether or not the passed string
+ *                actually is a valid URL.
+ *
+ * Parameters  :
+ *          1  :  url = URL to check
+ *
+ * Returns     :  True in case of valid URLs, false otherwise
+ *
+ *********************************************************************/
+int url_requires_percent_encoding(const char *url)
+{
+   static const char allowed_characters[128] = {
+      '\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', '#',  '$',  '%',  '&',  '\'',
+      '(',  ')',  '*',  '+',  ',',  '-',  '.',  '/',  '0',  '1',
+      '2',  '3',  '4',  '5',  '6',  '7',  '8',  '9',  ':',  ';',
+      '\0', '=',  '\0', '?',  '@',  'A',  'B',  'C',  'D',  'E',
+      'F',  'G',  'H',  'I',  'J',  'K',  'L',  'M',  'N',  'O',
+      'P',  'Q',  'R',  'S',  'T',  'U',  'V',  'W',  'X',  'Y',
+      'Z',  '[',  '\0', ']',  '\0', '_',  '\0', 'a',  'b',  'c',
+      'd',  'e',  'f',  'g',  'h',  'i',  'j',  'k',  'l',  'm',
+      'n',  'o',  'p',  'q',  'r',  's',  't',  'u',  'v',  'w',
+      'x',  'y',  'z',  '\0', '\0', '\0', '~',  '\0'
+   };
+
+   while (*url != '\0')
+   {
+      const unsigned int i = (unsigned char)*url++;
+      if (i >= sizeof(allowed_characters) || '\0' == allowed_characters[i])
+      {
+         return TRUE;
+      }
+   }
+
+   return FALSE;
+
+}
+
+
 /*********************************************************************
  *
  * Function    :  parse_http_url
diff --git a/urlmatch.h b/urlmatch.h
index d7a7a41b..cbf864de 100644
--- a/urlmatch.h
+++ b/urlmatch.h
@@ -1,6 +1,6 @@
 #ifndef URLMATCH_H_INCLUDED
 #define URLMATCH_H_INCLUDED
-#define URLMATCH_H_VERSION "$Id: urlmatch.h,v 1.16 2009/06/03 16:42:49 fabiankeil Exp $"
+#define URLMATCH_H_VERSION "$Id: urlmatch.h,v 1.17 2011/09/04 11:10:56 fabiankeil Exp $"
 /*********************************************************************
  *
  * File        :  $Source: /cvsroot/ijbswa/current/urlmatch.h,v $
@@ -8,7 +8,7 @@
  * Purpose     :  Declares functions to match URLs against URL
  *                patterns.
  *
- * Copyright   :  Written by and Copyright (C) 2001-2002, 2006 the SourceForge
+ * Copyright   :  Written by and Copyright (C) 2001-2002, 2006 the
  *                Privoxy team. http://www.privoxy.org/
  *
  *                Based on the Internet Junkbuster originally written
@@ -50,6 +50,8 @@ extern jb_err parse_http_request(const char *req, struct http_request *http);
 extern jb_err parse_http_url(const char *url,
                              struct http_request *http,
                              int require_protocol);
+extern int url_requires_percent_encoding(const char *url);
+
 #define REQUIRE_PROTOCOL 1
 
 extern int url_match(const struct url_spec *pattern,
-- 
2.39.2