#!/usr/bin/env bash

## 

usage() {
	echo 'Looks up ip via ldap and creates a krbconfig based on DC domain'
	echo 'USAGE: $0 <IP> '
	exit 1
}

[[ -z $1 ]] && usage

ip=$1
domain=$(ldapsearch -x -H "ldap://$ip" -s base namingcontexts -b "" | awk -F'[=,]' \
	'/namingcontexts:/ {print $2"."$4;exit}')

[[ $? -ne 0 ]] && echo 'ldapsearch failed' && exit 1

realm=${domain^^}
outfile="$domain.krb.conf"

cat << EOF | sed \
-e "s/{{REALM_PLACEHOLDER}}/$realm/g" \
-e "s/{{domain_placeholder}}/$domain/g" \
-e "s/{{ip_placeholder}}/$ip/g" > "$outfile"
[libdefaults]
    default_realm = {{REALM_PLACEHOLDER}}
    dns_lookup_realm = true
    dns_lookup_kdc = true

[realms]
    {{REALM_PLACEHOLDER}} = {
        kdc = {{ip_placeholder}}:88
        admin_server = {{ip_placeholder}}:749
        default_domain = {{domain_placeholder}}
    }

[domain_realm]
    {{domain_placeholder}} = {{REALM_PLACEHOLDER}}
    .{{domain_placeholder}} = {{REALM_PLACEHOLDER}}
EOF

echo "[+] Domain: $domain @ $ip"
echo '[+] Created custom_krb5.conf'
echo '' 
echo 'To use: '
echo "export KRB5_CONFIG=\$PWD/$outfile"
echo ''