Technology

The version field in a TLS ClientHello message tells the server the highest protocol version the client supports, but it appears in three distinct places with different roles. Understanding where and how each version field is used helps troubleshoot handshake failures and interoperability issues with legacy implementations.

Learn how to verify that your file system supports hole punching by creating a test file, punching a hole with fallocate, and confirming the space savings with du.

Lose track of which private key pairs with which certificate? Use OpenSSL to compare public key hashes and confirm the match in seconds.

A quick reference for LDAP result and error codes, covering both server-side responses and client-side indicators, including Active Directory-specific sub-codes under error 49.

A quick reference for Kerberos enctype numbers and what they map to, so you can stop guessing which cipher a ticket is actually using.

A look at how Java’s built-in Kerberos implementation uses cRealm and sRealm to determine the path between client and service realms, including hierarchical traversal and capaths configuration.