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> |
this is still blowing my mind.
This will not work in IE7 and older versions. Since only few people are using this old browser replacements, I would not consider this critical.
hey @nignag, would you mind taking the comments out of your package.json?
Any idea what I should change to make it work for IE7 and older ? In my company everyone is using IE<=9 BUT with IE7 compatibility mode (blocked by I/T), and this code doesn't work in that case :-/
Thanks.
try chaning the bracket notation on line 16 and 18 to .charAt(). otherwise sneak up to your co-workers stations and install chromeframe. :)
@Kambfhase yes it works like that. Thanks!
wait, did .charAt work or did sneaking up on your coworkers work? nyuk.
you could also use .split('') on both input string and translation map.
109 now if you had not seen: http://sla.ckers.org/forum/read.php?24,36342,page=2#msg-42491
Here are the tests if anyone is interested: http://jsperf.com/base64-encode-js
@LeverOne: (d-=-.75) looks like it can be reduced to (d+=.75)
@atk
Unfortunately, not. This is a trick to prevent the concatenation, since d is a string initially. Therefore, d+=.75 == '.75', then '.75.75', etc.
@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
ris not declared and spills the global scope. Since you do have enough chars left that should be no problem though.