added drill, dig or host as alternatives to nslookup

getssl

@@ -176,10 +176,11 @@
 # 2017-01-02 Added option to limit amount of old versions to keep (2.01)
 # 2017-01-03 Created check_config function to list all obvious config issues (2.02)
 # 2017-01-10 force renew if FORCE_RENEWAL file exists (2.03)
+# 2017-01-12 added drill, dig or host as alternatives to nslookup (2.04)
 # ----------------------------------------------------------------------------------------
 
 PROGNAME=${0##*/}
-VERSION="2.03"
+VERSION="2.04"
 
 # defaults
 ACCOUNT_KEY_LENGTH=4096
@@ -369,7 +370,21 @@ check_config() { # check the config files for all obvious errors
         config_errors=true
       fi
       # check domain exist
-      if [[ "$(nslookup -query=AAAA "${d}"|grep -c "^${d}.*has AAAA address")" -ge 1 ]]; then
+      if [[ "$DNS_CHECK_FUNC" == "drill" ]] || [[ "$DNS_CHECK_FUNC" == "dig" ]]; then
+        if [[ "$($DNS_CHECK_FUNC "${d}" SOA|grep -c "^${d}")" -ge 1 ]]; then
+          debug "found IP for ${d}"
+        else
+          info "${DOMAIN}: DNS lookup failed for ${d}"
+          config_errors=true
+        fi
+      elif [[ "$DNS_CHECK_FUNC" == "host" ]]; then
+        if [[ "$($DNS_CHECK_FUNC "${d}" |grep -c "^${d}")" -ge 1 ]]; then
+          debug "found IP for ${d}"
+        else
+          info "${DOMAIN}: DNS lookup failed for ${d}"
+          config_errors=true
+        fi
+      elif [[ "$(nslookup -query=AAAA "${d}"|grep -c "^${d}.*has AAAA address")" -ge 1 ]]; then
         debug "found IPv6 record for ${d}"
       elif [[ "$(nslookup "${d}"| grep -c ^Name)" -ge 1 ]]; then
         debug "found IPv4 record for ${d}"
@@ -377,7 +392,7 @@ check_config() { # check the config files for all obvious errors
         info "${DOMAIN}: DNS lookup failed for $d"
         config_errors=true
       fi
-    fi # end http-01 check
+    fi # end using http-01 challenge
     ((dn++))
   done
 
@@ -675,7 +690,53 @@ get_auth_dns() { # get the authoritative dns server for a domain (sets primary_n
     return
   fi
 
-  res=$(nslookup -debug=1 -type=soa -type=ns "$1" ${gad_s})
+  if [[ "$DNS_CHECK_FUNC" == "drill" ]] || [[ "$DNS_CHECK_FUNC" == "dig" ]]; then
+    if [[ -z "$gad_s" ]]; then #checking for CNAMEs
+      res=$($DNS_CHECK_FUNC CNAME "$gad_d"| grep "^$gad_d")
+    else
+      res=$($DNS_CHECK_FUNC CNAME "$gad_d" "@$gad_s"| grep "^$gad_d")
+    fi
+    if [[ ! -z "$res" ]]; then # domain is a CNAME so get main domain
+      gad_d=$(echo "$res"| awk '{print $5}' |sed 's/\.$//g')
+    fi
+    if [[ -z "$gad_s" ]]; then #checking for CNAMEs
+      res=$($DNS_CHECK_FUNC NS "$gad_d"| grep "^$gad_d")
+    else
+      res=$($DNS_CHECK_FUNC NS "$gad_d" "@$gad_s"| grep "^$gad_d")
+    fi
+    if [[ -z "$res" ]]; then
+      error_exit "couldn't find primary DNS server - please set AUTH_DNS_SERVER in config"
+    else
+      all_auth_dns_servers=$(echo "$res" | awk '$4 ~ "NS" {print $5}' | sed 's/\.$//g'|tr '\n' ' ')
+    fi
+    if [[ $CHECK_ALL_AUTH_DNS == "true" ]]; then
+      primary_ns="$all_auth_dns_servers"
+    else
+      primary_ns=$(echo "$all_auth_dns_servers" | awk '{print $1}')
+    fi
+    return
+  fi
+
+  if [[ "$DNS_CHECK_FUNC" == "host" ]]; then
+    if [[ -z "$gad_s" ]]; then
+      res=$($DNS_CHECK_FUNC -t NS "$gad_d"| grep "name server")
+    else
+      res=$($DNS_CHECK_FUNC -t NS "$gad_d" "$gad_s"| grep "name server")
+    fi
+    if [[ -z "$res" ]]; then
+      error_exit "couldn't find primary DNS server - please set AUTH_DNS_SERVER in config"
+    else
+      all_auth_dns_servers=$(echo "$res" | awk '{print $4}' | sed 's/\.$//g'|tr '\n' ' ')
+    fi
+    if [[ $CHECK_ALL_AUTH_DNS == "true" ]]; then
+      primary_ns="$all_auth_dns_servers"
+    else
+      primary_ns=$(echo "$all_auth_dns_servers" | awk '{print $1}')
+    fi
+    return
+  fi
+
+  res=$(nslookup -debug=1 -type=soa -type=ns "$gad_d" ${gad_s})
 
   if [[ "$(echo "$res" | grep -c "Non-authoritative")" -gt 0 ]]; then
     # this is a Non-authoritative server, need to check for an authoritative one.
@@ -975,10 +1036,25 @@ revoke_certificate() { # revoke a certificate
 }
 
 requires() { # check if required function is available
-  result=$(which "$1" 2>/dev/null)
-  debug "checking for required $1 ... $result"
-  if [[ -z "$result" ]]; then
-    error_exit "This script requires $1 installed"
+  if [[ "$#" -gt 1 ]]; then # if more than 1 value, check list
+    for i in "$@"; do
+      if [[ "$i" == "${!#}" ]]; then # if on last variable then exit as not found
+        error_exit "this script requires one of: ${*:1:$(($#-1))}"
+      fi
+      res=$(which "$i" 2>/dev/null)
+      debug "checking for $i ... $res"
+      if [[ ! -z "$res" ]]; then # if function found, then set variable to function and return
+        debug "function $i found at $res  - setting ${!#} to $i"
+        eval "${!#}=\$i"
+        return
+      fi
+    done
+  else # only one value, so check it.
+    result=$(which "$1" 2>/dev/null)
+    debug "checking for required $1 ... $result"
+    if [[ -z "$result" ]]; then
+      error_exit "This script requires $1 installed"
+    fi
   fi
 }
 
@@ -1338,13 +1414,14 @@ get_os
 requires which
 requires openssl
 requires curl
-requires nslookup
+requires nslookup drill dig host DNS_CHECK_FUNC
 requires awk
 requires tr
 requires date
 requires grep
 requires sed
 requires sort
+requires mktemp
 
 # Check if upgrades are available (unless they have specified -U to ignore Upgrade checks)
 if [[ $_UPGRADE_CHECK -eq 1 ]]; then
@@ -1868,6 +1945,12 @@ if [[ $VALIDATE_VIA_DNS == "true" ]]; then
             check_result=$(nslookup -type=txt "_acme-challenge.${d}" "${ns}" \
                            | grep ^_acme -A2\
                            | grep '"'|awk -F'"' '{ print $2}')
+          elif [[ "$DNS_CHECK_FUNC" == "drill" ]] || [[ "$DNS_CHECK_FUNC" == "dig" ]]; then
+            check_result=$($DNS_CHECK_FUNC TXT "_acme-challenge.${d}" "@${ns}" \
+                           | grep ^_acme|awk -F'"' '{ print $2}')
+          elif [[ "$DNS_CHECK_FUNC" == "host" ]]; then
+            check_result=$($DNS_CHECK_FUNC -t TXT "_acme-challenge.${d}" "${ns}" \
+                           | grep ^_acme|awk -F'"' '{ print $2}')
           else
             check_result=$(nslookup -type=txt "_acme-challenge.${d}" "${ns}" \
                            | grep ^_acme|awk -F'"' '{ print $2}')