From 1577983b9b3883b74e3e460ed4f8f6916ffaa3a5 Mon Sep 17 00:00:00 2001
From: Micael Karlberg <bmk@erlang.org>
Date: Wed, 26 Oct 2011 12:20:29 +0200
Subject: Fixed hex-decoding. OTP-9655

---
 lib/inets/src/http_lib/http_uri.erl | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

(limited to 'lib/inets/src/http_lib')

diff --git a/lib/inets/src/http_lib/http_uri.erl b/lib/inets/src/http_lib/http_uri.erl
index 3804af60f4..b470fd0b46 100644
--- a/lib/inets/src/http_lib/http_uri.erl
+++ b/lib/inets/src/http_lib/http_uri.erl
@@ -21,7 +21,8 @@
 -module(http_uri).
 
 -export([parse/1]).
--export([parse/1, encode/1, decode/1]).
+-export([encode/1, decode/1]).
+
 
 %%%=========================================================================
 %%%  API
@@ -45,16 +46,33 @@ encode(URI) ->
 			       $\\, $', $^, $%, $ ]),
     lists:append(lists:map(fun(Char) -> uri_encode(Char, Reserved) end, URI)).
 
-decode([$%,Hex1,Hex2|Rest]) ->
-    [hex2dec(Hex1)*16+hex2dec(Hex2)|decode(Rest)];
-decode([First|Rest]) ->
-    [First|decode(Rest)];
-decode([]) ->
+decode(String) ->
+    try
+	begin
+	    do_decode(String)
+	end
+    catch
+	throw:{bad_hex_value, _BadChar} ->
+	    %% The string is either badly encoded or a string 
+	    %% containing a % followed by a non-hex char.
+	    %% In any case, return as-is since there is nothing 
+	    %% we can do...
+	    %% Note that the valid hex-chars are: 0-9, a-f and A-F.
+	    String
+    end.
+
+do_decode([$%,Hex1,Hex2|Rest]) ->
+    [hex2dec(Hex1)*16+hex2dec(Hex2)|do_decode(Rest)];
+do_decode([First|Rest]) ->
+    [First|do_decode(Rest)];
+do_decode([]) ->
     [].
 
+
 %%%========================================================================
 %%% Internal functions
 %%%========================================================================
+
 parse_scheme(AbsURI) ->
     case split_uri(AbsURI, ":", {error, no_scheme}, 1, 1) of
 	{error, no_scheme} ->
@@ -138,4 +156,5 @@ uri_encode(Char, Reserved) ->
 
 hex2dec(X) when (X>=$0) andalso (X=<$9) -> X-$0;
 hex2dec(X) when (X>=$A) andalso (X=<$F) -> X-$A+10;
-hex2dec(X) when (X>=$a) andalso (X=<$f) -> X-$a+10.
+hex2dec(X) when (X>=$a) andalso (X=<$f) -> X-$a+10;
+hex2dec(X)                              -> throw({bad_hex_value, X}).
-- 
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