Book Image

Mastering Windows PowerShell Scripting (Second Edition) - Second Edition

By : Brenton J.W. Blawat
Book Image

Mastering Windows PowerShell Scripting (Second Edition) - Second Edition

By: Brenton J.W. Blawat

Overview of this book

PowerShell scripts offer a handy way to automate various chores. Working with these scripts effectively can be a difficult task. This comprehensive guide starts from scratch and covers advanced-level topics to make you a PowerShell expert. The first module, PowerShell Fundamentals, begins with new features, installing PowerShell on Linux, working with parameters and objects, and also how you can work with .NET classes from within PowerShell. In the next module, you’ll see how to efficiently manage large amounts of data and interact with other services using PowerShell. You’ll be able to make the most of PowerShell’s powerful automation feature, where you will have different methods to parse and manipulate data, regular expressions, and WMI. After automation, you will enter the Extending PowerShell module, which covers topics such as asynchronous processing and, creating modules. The final step is to secure your PowerShell, so you will land in the last module, Securing and Debugging PowerShell, which covers PowerShell execution policies, error handling techniques, and testing. By the end of the book, you will be an expert in using the PowerShell language.
Table of Contents (24 chapters)
Title Page
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

File catalogs


A file catalog is a new feature with Windows PowerShell 5.1. A file catalog is a reasonably lightweight form of File Integrity Monitoring (FIM). The file catalog generates and stores SHA1 hashes for each file within a folder structure and writes the result to a catalog file.

Note

About hashing:Hashing is a one-way process; a hash is not an encryption or encoding. A hash algorithm converts data of any length to a fixed-length value. The length of the value depends on the hashing algorithm used. MD5 hashing is one of the more common algorithms; it produces a 128-bit hash that can be represented by a 32-character string. SHA1 is rapidly becoming the default; it produces a 160-bit hash that can be represented by a 40-character string. PowerShell has a Get-FileHash command that can be used to calculate the hash for a file.

As the catalog is the basis for determining integrity, it should be maintained in a secure location, away from the set of files being analyzed.

New-FileCatalog

The...