Node-ldapjs: Issue reading thumbnailPhoto from LDAP

Created on 8 Jun 2013 · 5Comments · Source: ldapjs/node-ldapjs

Hi,

I am using the following code to extract the thumbnail photo of a user from LDAP:

var ldap = require('ldapjs');
var fs = require('fs');

var client = ldap.createClient({
url: 'ldap://someip:389'
});

var user = "someuser"

var opts = {
filter: '(sAMAccountName='+user+')',
scope: 'sub'
};

client.search('OU=someou,DC=somedc,DC=com', opts, function(err, res) {
//assert.ifError(err);

res.on('searchEntry', function(entry) {
var info = entry.object;
console.log('entry: ' + info.dn);
console.log('entry: ' + info.sn);
console.log('entry: ' + info.givenName);
console.log('entry: ' + info.title);
console.log('entry: ' + info.memberOf);
console.log('entry: ' + info.co);
console.log('entry: ' + info.manager);
console.log('entry: ' + info.mail);
fs.writeFile("./public/images/photos/"+user+"Thumb.jpg", info.thumbnailPhoto, function(err) {
if(err) {
console.log("errror writing thumbnail: "+err);
} else {
console.log("thumbnail was saved!");
}
});
//...

As it is it fails to write a proper image as it transforms some of the bytes to something else. Can someone help?
For example, the first 4 bytes get transform from:
ffd8 ffe0
to
efbf bdef bfbd efbf bdef bfbd

Thanks.

Source

lmusat

Most helpful comment

The problem is that the attribute values are converted from buffers to strings, and ldapjs does not know that the thumbnail is really binary.
Here is a function which works similar as entry.object in the example above, but returns the original buffers instead of the strings for all attributes except for dn and controls (the code is adapted from lib/messages/search_entry.js from the getter of object)

function _convert(entry) {
    var obj = {
      dn: entry.dn.toString(),
      controls: []
    };
    entry.attributes.forEach(function (a) {
      var item = a.buffers;
      if (item && item.length) {
        if (item.length > 1) {
          obj[a.type] = item.slice();
        } else {
          obj[a.type] = item[0];
        }
      } else {
        obj[a.type] = [];
      }
    });
    entry.controls.forEach(function (element, index, array) {
      obj.controls.push(element.json);
    });
    return obj;
  }

You can use entry.object for the non-binary properties and the result of this function for the binary properties. I hope this helps.

ghost on 21 Jun 2013

👍5

All 5 comments

function _convert(entry) {
    var obj = {
      dn: entry.dn.toString(),
      controls: []
    };
    entry.attributes.forEach(function (a) {
      var item = a.buffers;
      if (item && item.length) {
        if (item.length > 1) {
          obj[a.type] = item.slice();
        } else {
          obj[a.type] = item[0];
        }
      } else {
        obj[a.type] = [];
      }
    });
    entry.controls.forEach(function (element, index, array) {
      obj.controls.push(element.json);
    });
    return obj;
  }

You can use entry.object for the non-binary properties and the result of this function for the binary properties. I hope this helps.

ghost on 21 Jun 2013

👍5

Thanks a lot! It worked.
I changed a bit the function you provided as I saw that the SearchEntry.object getter was almost the same, only using vals instead of buffers. My version only checks for thumbnailPhoto field to be object, not string:

function getProperObject(entry) {
  var obj = {
    dn: entry.dn.toString(),
    controls: []
  };
  entry.attributes.forEach(function (a) {
    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] = [];
    }
  });
  entry.controls.forEach(function (element, index, array) {
    obj.controls.push(element.json);
  });
  return obj;
}

Thanks again!

lmusat on 12 Aug 2013

👍1

Searched for a good deal of time on how to solve this before I found this which worked. Thanks!