A base64encoder with padding, what shall i say more? This version now includes the amazing improvements made by Jonas Magazinius and LeverOne, for more details visit the "sla.ckers"-forum @ http://sla.ckers.org/forum/read.php?24,36342 (web.archive.org)
If you are looking for a decoder give https://gist.github.com/atk/1020396 a try.
var
sigma ="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
, sample = "140bytes rocks!"
, encoded = (function(...){...})(sample, sigma);| function( | |
| a, /* input text */ | |
| b, /* mapping table */ | |
| c, /* working block */ | |
| d, /* input char index */ | |
| e /* output text */ ){ | |
| for( | |
| // initialize char indices | |
| d=e=''; | |
| // cast d to int (floor) | |
| // if the next input index does not exist: | |
| // change the mapping table to "=" | |
| // check if d has no fractional digits | |
| a[d|0]||(b='=',d%1); | |
| e+=b[ 63 & c >> 8 - d % 1 * 8 ] // "8 - d % 1 * 8" generates the sequence 2, 4, 6, 8 (first value for d is 0.75) | |
| )c = c << 8 | a.charCodeAt( d-=-.75 ); // note: "d -= -3/4" works too | |
| return e | |
| } | |
| function(a,b,c,d,e){for(d=e='';a[d|0]||(b='=',d%1);e+=b[63&c>>8-d%1*8])c=c<<8|a.charCodeAt(d-=-.75);return e} |
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| Version 2, December 2004 | |
| Copyright (C) 2011 YOUR_NAME_HERE <YOUR_URL_HERE> | |
| Everyone is permitted to copy and distribute verbatim or modified | |
| copies of this license document, and changing it is allowed as long | |
| as the name is changed. | |
| DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE | |
| TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION | |
| 0. You just DO WHAT THE FUCK YOU WANT TO. |
| { | |
| "name": "Base64Encoder", | |
| "description": "A JavaScript Base64 encoder in 109 Bytes.", | |
| "keywords": ["base64", "encode", "rfc2045", "sla.ckers", "btoa"], | |
| "license" : "DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE", | |
| "url" : "http://sla.ckers.org/forum/read.php?24,36342" | |
| } |
| <html> | |
| <body> | |
| <script type="text/javascript"> | |
| (function(){ | |
| var f = function(a,b,c,d,e){for(d=e='';a[d|0]||(b='=',d%1);e+=b[63&c>>8-d%1*8])c=c<<8|a.charCodeAt(d-=-.75);return e} | |
| , test = { | |
| '' : '' | |
| ,'AA==' : '\0' | |
| ,'AAA=' : '\0\0' | |
| ,'AAAA' : '\0\0\0' | |
| ,'AAEC' : '\0\1\2' | |
| ,"Zg==" : "f" | |
| ,"Zm8=" : "fo" | |
| ,"Zm9v" : "foo" | |
| ,"Zm9vYg==" : "foob" | |
| ,"Zm9vYmE=" : "fooba" | |
| ,"Zm9vYmFy" : "foobar" | |
| } | |
| , error = 0; | |
| ; | |
| for( i in test ) { | |
| var r = f(test[i], "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/", "="); | |
| if( r != i ) { | |
| error++; | |
| document.writeln( 'Expected "'+i+'" for "'+test[i]+'" but got "'+ r + ""<br>" ); | |
| } | |
| } | |
| if( error > 0) { | |
| document.writeln( "<br>"+error+ " tests failed!<br>" ); | |
| } else { | |
| document.writeln( "<br>Everything is fine!<br>" ); | |
| } | |
| })(); | |
| </script> | |
| </body> | |
| </html> |
@LeverOne: thanks for clarification.
@LeverOne: I always wonder how you find so many magic sequences. Could you tell us how?
@tsaniel
This process is almost creative, there are no special spells.
Could you please explain me what this "d%1" in "a[d|0]||(b='=',d%1);". Why don't just "a[d|0]||b='=';"?
d%1 tests for fractional digits, so the check is necessary
Hi all,
I am using using esp idf environment on esp32 board. I want to decode url.
URL>>file:///F:/s?ssid=cabin+336&Passkey=Cabin336%40efc
In above url, 'Cabin336%40efc' includes '%40' which has its decoded value '@'
so how to decode this?
I tried to use base64.h library file from esp idf but gives an error..
fatal error: base64.h: No such file or directory
@atk
Unfortunately, not. This is a trick to prevent the concatenation, since
dis a string initially. Therefore,d+=.75=='.75', then'.75.75', etc.