encodage mime64 binaire en local

[ Lien ]

<script type="text/javascript">
var encode64Table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var binEncode = new Array();
for (i=0;i<encode64Table.length;i++)
binEncode[binBits(i, 6)] = encode64Table.charAt(i);
function base64_encode(chaineAconvertir) {
var base64String = "";
var groupe128bits = "";
for (var i=0;i<chaineAconvertir.length;i = i+3) {
groupe24bits = chaineAconvertir.substr(i,3);
nbCar = groupe24bits.length;
var binContainer = "";
for (var j=0;j<nbCar;j++)
binContainer += binBits(groupe24bits.charCodeAt(j), 8);
binContainer = nbCar==1?binContainer+"0000":nbCar==2?binContainer+"00":binContainer;
for (var k=0;k<binContainer.length;k = k + 6)
base64String += binEncode[binContainer.substr(k,6)];
}
base64String = nbCar==1?base64String+"==":nbCar==2?base64String+"=":base64String;
return base64String;
}
function binBits(nbr, lng) {
var bin = nbr.toString(2);
return "00000000".substr(0, lng - bin.length ) + bin;
}
</script>

La façon de l'utiliser :