Percent-encode URL Twice - php

I have been given some instructions to percent encode a URL twice. I know how to percent encode a URL once but how do you do it twice?
Surly when it is encoded once, it will be the same when encoded again.
Have I missed something?
Instructions or algorithm would be great!

It won't be the same since you encode the % used for encoding.
$url = 'http://www.youtube.com/watch?v=35_0IN36rUI'
echo $url;
echo urlencode($url);
echo urlencode(urlencode($url));
will give:
http://www.youtube.com/watch?v=35_0IN36rUI
http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3D35_0IN36rUI
http%253A%252F%252Fwww.youtube.com%252Fwatch%253Fv%253D35_0IN36rUI

To doubly encode the Url in php do:
$encodedUrl = urlencode(urlencode($url));
Definitely not the same output when encoded twice. The first adds percent encodings and the second will actually encode those percent signs... For example:
urlencode('guts & glory'); // "guts+%26+glory"
urlencode(urlencode('guts & glory')); // "guts%2B%2526%2Bglory"

Related

php URL decode get '+' from URL

So I am trying to encode/decode a url that when decoded will return the encoded + symbols from teh url. For example, I encodewebsite.com/index.php?eq=1+12 which when encoded turns the + into %2B, as it should. When I retrieve the value from $_REQUEST['eq'] and use urldecode() it echo's as "1 12". I cannot seem to get the decode to bring back the + so to speak. Am I doing something wrong here, or is there a more efficient/better way to go about doing this? Here is the exact encode/decode lines I use.
Submit Page
<?php
$eq = "1+12";
$send = '<a href="website.com/index.php?eq='.urlencode($eq).'</a>';
echo $send;
Retrieval page
<?php
$eq = urldecode($_REQUEST['eq']);
echo $eq;
?>
Don't run urldecode, the data in $_REQUEST is automatically decoded for you.
A plus sign, in a URL, is an encoded space. PHP decodes the hex value to a + automatically. Then, by running the result through urldecode, you are manually (and incorrectly) decoding the + to a .
Try using the function rawurldecode() instead of urldecode()
I encode it in JavaScript with encodeURIComponent() and decode it in PHP with rawurldecode() and it encodes/decodes properly for me, including the "+", but NOT with urldecode()

Translate URLENCODED data into UTF-8 in PHP

I've got a string that is in my database like 中华武魂 when I post my request to retrieve the data via my website I'm getting the data to the server in the format %E4%B8%AD%E5%8D%8E%E6%AD%A6%E9%AD%82
What decoding steps to I have to take in order to get it back to the usable form?
While also cleaning the user input to ensure they're not going to try an SQL injection attack?
(escape string before or after encoding?)
EDIT:
rawurldecode(); // returns "中åŽæ­¦é­‚"
urldecode(); // returns "中åŽæ­¦é­‚"
public function utf8_urldecode($str) {
$str = preg_replace("/%u([0-9a-f]{3,4})/i","&#x\\1;",urldecode($str));
return html_entity_decode($str,null,'UTF-8');
}
// returns "中åŽæ­¦é­‚"
... which actually works when I try and use it in an SQL statement.
I think because I was doing an echo and die(); without specifying a header of UTF-8 (thus I guess that was reading to me as latin)
Thanks for the help!
When your data is actually that percent-encoded form, you just have to call rawurldecode:
$data = '%E4%B8%AD%E5%8D%8E%E6%AD%A6%E9%AD%82';
$str = rawurldecode($data);
This suffices as the data already is encoded in UTF-8: 中 (U+4E2D) is encoded with the byte sequence 0xE4B8AD in UTF-8 and that is encoded with %E4%B8%AD when using the percent-encoding.
That your output does not seem to be as expected is probably because the output is interpreted with the wrong character encoding, probably Windows-1252 instead of UTF-8. Because in Windows-1252, 0xE4 represents ä, 0xB8 represents ¸, 0xAD represents å, and so on. So make sure to specify the output character encoding properly.
Use PHP's urldecode:
http://php.net/manual/en/function.urldecode.php
You have choices here: urldecode or rawurldecode.
If you had encoded your string using urlencode, you must use urldecode because of the way spaces are handled. While urlencode converts spaces to +, it is not the same with rawurlencode.

get values in url

I need to get values in the url as it is
ex:
http://www.example.com/index?url=1+LY2ePh1pjX4tjZ4+GS393Y2pjd16Cbq63T3tbfzMzd16CarA==
but vriable url give me value of "1 LY2ePh1pjX4tjZ4 GS393Y2pjd16Cbq63T3tbfzMzd16CarA=="
Even though i have expected "1+LY2ePh1pjX4tjZ4+GS393Y2pjd16Cbq63T3tbfzMzd16CarA=="
any one can help me for this or know the reason
You see, you need to encode certain characters if you need to send them in a URL. For further references, I suggest you should read this Page. It seems that the URL you are getting isn't being encoded properly. If the URL is coming from your site, then I would suggest you to encode it properly.
In PHP, there is a function called urlencode, which may help you with this task.
A short explanation
URLs can only be sent over internet using ASCII character set.If you want to send characters which is outside this set, you need to encode it.URL encoding replaces unsafe ASCII characters with % followed by two hexadecimal digits corresponding to the character values in the ISO-8859-1 character-set.
The client sending the request apparently isn't URL encoding the value correctly. You can re-encode it after it's being decoded like this:
urlencode($_GET["url"])
IT convert %2B to space
The parameter you sent is wrong, it should have been encoded like so..
<?php
echo '<a href="http://www.example.com/index?url=', urlencode('1+LY2ePh1pjX4tjZ4+GS393Y2pjd16Cbq63T3tbfzMzd16CarA=='), '">';
?>
i have added encoding correctly now,It convert == correctly, but + sign encode to %2B correctly but in decode process it convert to space
As it seems that you’re having a Base-64 value there: You can use the URL safe alphabet for Base-64 that uses - and _ instead of + and / respectively:
$base64 = "1+LY2ePh1pjX4tjZ4+GS393Y2pjd16Cbq63T3tbfzMzd16CarA==";
// plain Base-64 to URL safe Base-64
$base64_safe = strtr($base64, '+/', '-_');
// URL safe Base-64 to plain Base-64
$base64 = strtr($base64_safe, '-_', '+/');
And if you know the length of the data, you can also omit the = padding:
rtrim($base64, '=')

Removing the "%" encoding in URL string

I am attempting to open a page with window.open and it's not working. The path shown is like xyz/a%20b%20c%20.pdf, but it is supposed to be xyz/abc.pdf. If I remove the % and 20 manually, it works, how can I remove these characters using PHP?
Use urldecode:
(PHP 4, PHP 5)
urldecode — Decodes URL-encoded string
Description
string urldecode ( string $str )
Decodes any %## encoding in the given string. Plus symbols ('+') are decoded to a space character.
Example
echo urldecode('xyz/a%20b%20c%20.pdf');
This is known as URL Encoding. You need to decode the string. If you are using jQuery you should check out the URL Encode plug in.
You need to urldecode (as stated above).
However, you say that you can remove the %20 and it will work. I would say you need them, they decode to spaces. Check it out using this online url decoder:
http://www.convertstring.com/EncodeDecode/UrlDecode
it decodes to:
xyz/a b c .pdf
not
xyz/abc.pdf

PHP URL encoding method

How can I have PHP display this URL correctly?
Is there a working encoding method I can use that converts all of
253A%252F%252F
to
://
in
https%253A%252F%252Fvideos-private.s3.amazonaws.com%252Flesson05.flv
?
You should use double urldecode, i.e.,
$beuty_url = urldecode(urldecode("https%253A%252F%252Fbassrxprivate.s3.amazonaws.com%252Flesson05.flv"));
echo $beuty_url;
urldecode ;)
The urldecode function decodes any %## encoding in the given string.
In your "output" string you have %253A and so on.
Remove those %25 and everything will be fine.

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