I can’t get slapd to respond successfully to TLS or SSL connections using an RSA 2048-bit PEM certificate:
$ ldapsearch -x -ZZ -d1 -H ldap://FQDNhostname
TLS: loaded CA certificate file /etc/openldap/cacerts/FQDNhostname.cacert.pem.
TLS: error: tlsm_PR_Recv returned 0 - error 21:Is a directory
TLS: error: connect - force handshake failure: errno 21 - moznss error -5938
TLS: can't connect: TLS error -5938:Encountered end of file.
ldap_start_tls: Connect error (-11)
        additional info: TLS error -5938:Encountered end of file
$ openssl s_client -connect FQDNhostname:636 -CAfile /etc/openldap/cacerts/FQDNhostname.cacert.pem
140457427965768:error:140790E5:SSL routines:SSL23_WRITE:ssl handshake failure:s23_lib.c:184:
no peer certificate available
No client certificate CA names sent
SSL handshake has read 0 bytes and written 113 bytes
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
The following packages are installed on CentOS 6.2:
The /etc/openldap/ldap.conf file contains:
TLS_CACERT /etc/openldap/cacerts/FQDNhostname.cacert.pem
, which contains a chain of three certificates (root CA, intermediate/functional, and issuing).
The /etc/openldap/slapd.conf file contains:
TLSCipherSuite HIGH:+SSLv3
TLSCertificateFile      /etc/openldap/FQDNhostname.cert.pem
TLSCertificateKeyFile   /etc/openldap/FQDNhostname.key.pem
The server is acting as a proxy to an Active Directory, and therefore I only have one LDAP database defined. My intention is to use LDAPS for communication between the client and LDAP proxy servers:
database                ldap
suffix                      "dc=abc,dc=local"
uri                          "ldap://IPaddress1/ ldap://IPaddress2/ ldap://IPaddress3/ ldap://IPaddress4/"
chase-referrals    yes
noundeffilter       yes
use-temporary-conn      yes
The certificate and private key are located in /etc/openldap/, with the following permissions :
-r--r-----. 1 ldap ldap 2076 Feb 21 15:30 FQDNhostname.cert.pem
-r--r-----. 1 ldap ldap 1675 Feb 21 15:35 FQDNhostname.sdi.key.pem
The CN of the certificate matches the FQDN host name of the LDAP server.
The private key is not password protected.
Everything checks out OK by testing the certificate using openssl:
$ openssl verify -purpose sslserver -CAfile /etc/openldap/cacerts/FQDNhostname.cacert.pem /etc/openldap/FQDNhostname.cert.pem
/etc/openldap/FQDNhostname.cert.pem: OK
OpenSSL client/server connections work fine too:
openssl s_server -cert /etc/openldap/FQDNhostname.cert.pem -key /etc/openldap/FQDNhostname.key.pem -cipher 'HIGH:+SSLv3
openssl s_client -connect FQDNhostname:4433 -CAfile /etc/openldap/cacerts/FQDNhostname.cacert.pem
Bryce Powell