Recently I ran into a problem where one DNS server setup using Bind9 was not responding to external queries. systemctl status bind9 –no-pager –full shows “Denied“ Common issues (listed below) that can cause the problem were not there. Bind9 was running properly The server was listening on both IPv4 and IPv6 Port 53 was open… Continue reading Bind server not responding to external queries
Month: May 2019
Manually adding a DNS Zone to Bind9 server
Create a Zone file in /etc/bind/ Example – /etc/bind/pri.domain.com Add the entries . Example below $TTL 3600 @ IN SOA ns2.dnserver.net. manish.gmail.com. ( 2019051606 ; serial, todays date + todays serial # 7200 ; refresh, seconds 540 ; retry, seconds 604800 ; expire, seconds 3600 ) ; minimum, seconds ; domain.com. 3600 A xxx.xxx.xxx.xxx mail… Continue reading Manually adding a DNS Zone to Bind9 server
Two Way Encryption or Hashing using Key
This is using PHP and openssl_decrypt/openssl_encrypt Encrypting the string $key = “xxxxxxxxxxx”; //11 characters $ivlen = openssl_cipher_iv_length(“aes-256-cbc-hmac-sha256″); $iv = openssl_random_pseudo_bytes($ivlen); $hash = openssl_encrypt(STRING TO HASH,”aes-256-cbc-hmac-sha256”,$key,0,$iv); $iv = bin2hex($iv); // iv generated is in binary – converted to HEX for passing through SESSION or POST or URL Decrypting back the string $key = “xxxxxxxxxxx”; $hash =… Continue reading Two Way Encryption or Hashing using Key