Cannot perform LDAP SEARCH operation (ldapjs + osixia/openldap)

Question

fellow developpers,

I have deployed a docker image osixia/openldap and osixia/phpldapadmin. I am developing an application in NodeJS that uses "ldapjs".

What works:

• From the "phpldapadmin" web app, I can access the data from the "openldap" deployment; my tree is as follows:

+--> dc=example,dc=org (2)
  +--> ou=Groups (2)
  | ---> cn=groupe1
  | ---> cn=groupe2
  +--> ou=Users (3)
  | ---> cn=user1
  | ---> cn=user2
  | ---> cn=user3

• From the "phpldapadmin" web app, I can correctly execute a search request on "BaseDN = dc=example,dc=org" and filter="(uniqueMember=cn=user1,ou=users,dc=example,dc=org)", the interface shows me the list of groups to which user1 belongs.
• From my NodeJS code, I perform a bind request to implement the authentication functionality; this works when I provide the correct credentials.

What doesn't work:

• From my NodeJS code, I make a search request to implement the authorization functionality (checking group membership). Here are the logs from my openLDAP instance:

LDAP-directory           | 65148901 conn=1003 op=0 BIND dn="cn=admin,dc=example,dc=org" method=128
LDAP-directory           | 65148901 conn=1003 op=0 BIND dn="cn=admin,dc=example,dc=org" mech=SIMPLE ssf=0
LDAP-directory           | 65148901 conn=1003 op=0 RESULT tag=97 err=0 text=
LDAP-directory           | 65148901 conn=1003 op=1 SRCH base="dc=example,dc=org" scope=2 deref=3 filter="(uniqueMember=cn=user1,ou=users,dc=example,dc=org)"
LDAP-directory           | 65148901 conn=1003 op=1 SRCH attr=cn
LDAP-directory           | 65148901 <= mdb_equality_candidates: (uniqueMember) not indexed
LDAP-directory           | 65148901 conn=1003 op=1 SEARCH RESULT tag=101 err=0 nentries=2 text=

• An exception is thrown right after in my backend:

Cannot read properties of undefined (reading 'toLowerCase')

Please note I have no usage of toLowerCase function in my whole backend codebase

• Here's the error stack; it seems like the problem comes from the LDAP WS:

API        |     at /usr/src/app/main.api.js:2:762329
API        |     at I.<anonymous> (/usr/src/app/main.api.js:2:759311)
API        |     at I.emit (node:events:514:28)
API        |     at I.write (/usr/src/app/main.api.js:2:775328)
API        |     at Socket.<anonymous> (/usr/src/app/main.api.js:2:758828)
API        |     at Socket.emit (node:events:514:28)
API        |     at addChunk (node:internal/streams/readable:343:12)
API        |     at readableAddChunk (node:internal/streams/readable:316:9)
API        |     at Readable.push (node:internal/streams/readable:253:10)
API        |     at TCP.onStreamRead (node:internal/stream_base_commons:190:23)

• Here is my current code:

connection.bind(this.config.adminUsername, this.config.adminPassword, (err) => {
    if(err) return reject(err)

    const query: SearchOptions = {
        scope: 'sub',
        filter: 'uniqueMember=' + fullQualifiedName,
        attributes: ['cn'],
    }

    connection.search(this.config.baseDN, query, (err, searchRes) => {
        if(err) return reject(err)

        const groups = []
        searchRes.on('searchEntry', (group) => {
            groups.push(group)
        })

        searchRes.on('error', (err) => {
            reject(err)
        })

        searchRes.on('end', () => {
            resolve({
                // rights from groups
            })
            connection.destroy()
        })
    })
})

TLDR: Authentication works perfectly, I can bind to the server. I can perform searches from the "phpldapadmin" web app and obtain the expected results. However, when performing a search from my NodeJS code, the issue occurs. It seems that the search results are either not returned correctly or are undefined, causing the 'toLowerCase' error.

Versions involved:

• Nodejs:latest
• osixia/phpldapadmin:latest
• osixia/openldap:latest
• ldapjs: "^3.0.5",

Thank you, you're my last hope before mental hospital.

I've tried pretty everything the last 2 days, I hope someone got the same issue and figure it out something to solve the situation.