Pin ldap3 version and update params for SSL validation (#11)

Author: nhoffman

Singularity

@@ -49,7 +49,7 @@ From: nickjer/singularity-r
     "https://bootstrap.pypa.io/get-pip.py"
   python3 get-pip.py
   rm -f get-pip.py
-  pip3 install ldap3
+  pip3 install 'ldap3==2.9'
 
   # Clean up
   rm -rf /var/lib/apt/lists/*

Singularity.3.6.2

@@ -49,7 +49,7 @@ From: nickjer/singularity-r:3.6.2
     "https://bootstrap.pypa.io/get-pip.py"
   python3 get-pip.py
   rm -f get-pip.py
-  pip3 install ldap3
+  pip3 install 'ldap3==2.9'
 
   # Clean up
   rm -rf /var/lib/apt/lists/*

ldap_auth.py

@@ -19,8 +19,9 @@
     LDAPInvalidCredentialsResult - 49 - invalidCredentials - None - 80090308: LdapErr: DSID-0C09042F, comment: AcceptSecurityContext error, data 52e, v2580 - bindResponse - None
     failed
 
-[0] A certificate file is only required if the default system
-certificate store is not accepted by the LDAP server.
+[0] A certificate file is only required if mandated by the LDAP host
+and the default system certificate store is not accepted by the LDAP
+server.
 
 """
 
@@ -77,8 +78,7 @@ def main(arguments):
             use_ssl=True,
             tls=ldap3.Tls(
                 ca_certs_file=args.cert_file,
-                # validate=ssl.CERT_NONE,
-                validate=ssl.CERT_REQUIRED,
+                validate=ssl.CERT_OPTIONAL,
             ),
             get_info=ldap3.NONE,
             connect_timeout=args.timeout,