Creating Hashes from Text

by May 16, 2019

A hash is a way to uniquely identify a text without exposing the actual text. Hashes are used to identify texts, find duplicate file content, and validate passwords. PowerShell 5 and better even comes with a cmdlet to calculate hash values for files: Get-FileHash.

However, Get-FileHash has no way of calculating hashes from strings. Instead of saving string values to file just to calculate the hash value, you can use a so-called memory stream instead. Here is a piece of code that calculates a hash from any string:

$Text = 'this is the text that you want to convert into a hash'

$stream = [IO.MemoryStream]::new([Text.Encoding]::UTF8.GetBytes($Text))
$hash = Get-FileHash -InputStream $stream -Algorithm SHA1


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