s3xy-node implementation

gistify306261.js

app.get('/sign_s3', function(req, res){
    var object_name = req.query.s3_object_name;
    var mime_type = req.query.s3_object_type;

    var now = new Date();
    var expires = Math.ceil((now.getTime() + 10000)/1000); // 10 seconds from now
    var amz_headers = "x-amz-acl:public-read";

    var put_request = "PUT\n\n"+mime_type+"\n"+expires+"\n"+amz_headers+"\n/"+S3_BUCKET+"/"+object_name;

    var signature = crypto.createHmac('sha1', AWS_SECRET_KEY).update(put_request).digest('base64');
    signature = encodeURIComponent(signature.trim());
    signature = signature.replace('%2B','+');

    var url = 'https://'+S3_BUCKET+'.s3.amazonaws.com/'+object_name;

    var credentials = {
        signed_request: url+"?AWSAccessKeyId="+AWS_ACCESS_KEY+"&Expires="+expires+"&Signature="+signature,
        url: url
    };
    res.write(JSON.stringify(credentials));
    res.end();
});