Display LDAP thumbnail photos

Owned by Genhan Chen
Last updated: Jan 19, 2018
1 min read

Problem

In our Node.js applications, we use passport-ldapauth library to authenticate\retrieve the user info.  

In the returned user object, the thumbnailPhoto field cannot be displayed as an image in HTML. It is because the ldapjs library convert all types of attributes as string. 

Solution

In the file node_modules\ldapjs\lib\messages\search_entry.js, replace 

if (a.vals && a.vals.length) {
  if (a.vals.length > 1) {
    obj[a.type] = a.vals.slice();
  } else {
    obj[a.type] = a.vals[0];
  }
} else {
  obj[a.type] = [];
}

as

var buf = a.buffers;
var val = a.vals;
var item;
if ( a.type == 'thumbnailPhoto' )
    item = buf;
else
    item = val;
if (item && item.length) {
    if (item.length > 1) {
        obj[a.type] = item.slice();
    } else {
        obj[a.type] = item[0];
    }
} else {
    obj[a.type] = [];
}


Then, overwrite the thumbnailPhoto attribute to be a string used in <img src='{thumbnailPhoto}'>:


router.post('/login',
    passport.authenticate('ldapauth'),
    (req, res) => {
        req.user.thumbnailPhoto = 'data:image/jpeg;base64,' + Buffer.from(req.user.thumbnailPhoto).toString('base64');
        res.render('profile', req.user);
    });

https://github.com/joyent/node-ldapjs/issues/137