I'm currently preparing migration to Samba 4 at my office, and facing issues in my lab network. Installed Samba 4 AD DC on a Debian 9 server, so far it's working properly, could join machines to the domain and access to Samba internal LDAP from external tools using unencrypted ldap://[IP] on port 389.

I'm now trying to configure LDAP access through SSL/TLS following this page instructions:


Wether i'm using autogenerated self-signed certificates or creating a custom one It always fail at the point of verifying the cert:

openssl verify -verbose cert.pem
error 18 at 0 depth lookup: self signed certificate
error cert.pem: verification failed

I checked private key:

# openssl rsa -check -in key.pem 
RSA key ok
writing RSA key

I tried to check if private key and cert are corresponding:

# openssl x509 -noout -modulus -in cert.pem | openssl md5
   (stdin)= ce3ca7afcfe6a02ded1ed83938954940
# openssl rsa -noout -modulus -in key.pem | openssl md5
(stdin)= ce3ca7afcfe6a02ded1ed83938954940

Here's global section of my smb.conf file:

tls enabled  = yes
tls keyfile  = tls/key.pem
tls certfile = tls/cert.pem
tls cafile   = tls/ca.pem

I also tried to move the auto-generated files from their original destination






curl commands answers this:

#curl ldaps://host.domain.fr
curl: (60) SSL certificate problem: unable to get local issuer certificate

But I successfully connect with a

# curl --insecure ldaps://host.domain.fr

# curl --cacert /usr/local/samba/private/tls/ca.pem ldaps://host.domain.fr

Well, any advice about configuration or troubleshooting tips is warmly welcome!

  • 1
    I am not sure your actual absolute paths are valid : e.g /tls/cert.pem. You shoud remove the extra / at the beginning : e.g tls/cert.pem (for keyfile, certfile, cafile). Then put your cert files in /usr/local/samba/private/tls/
    – krisFR
    Sep 14 '17 at 10:54
  • You're right. It didn't solve entirely the issue, but progress were made. I edited the post
    – Sam C
    Sep 14 '17 at 12:26
  • From what i see it is working now (your very last curl command). You need to import the CA certificate on the client, this is kind of what you do when you specify --cacert whitin your last curl command.
    – krisFR
    Sep 14 '17 at 13:25

OK, I solved my issue.

Followed this procedure to create self-signed certificate for Samba 4

Go to auto-generated certificate directory, remove existing ones and create your owns into same directory. then restart samba

# cd /usr/local/samba/private/tls ## if you compiled samba from sources
# cd /var/lib/samba/private/tls ## if you installed samba from repos

# rm *.pem
# openssl req -newkey rsa:2048 -keyout myKey.pem -nodes -x509 -days 365 -out myCert.pem

Add this to your /etc/samba/smb.conf

tls enabled  = yes
tls keyfile  = tls/myKey.pem
tls certfile = tls/myCert.pem
tls cafile   = 

Then restart Samba

To make successful ldapsearch command follow this topic advice and add


to your ldap.conf file.

One thing which kept me in error was that

openssl verify myCert.pem

will never work on my config (Debian 9.0 "Stretch" - OpenSSL 1.1.0f) I retried my keys under OpenSSL 1.0.2 and worked just fine. I'm not sure if it's caused by os or just openssl version...

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