How to hash only specific metdata in powershell

To hash specific metadata in PowerShell, you can use the Get-FileHash cmdlet along with the Select-Object cmdlet to extract and hash specific metadata properties of a file. Here's an example:

powershellCopy code
# Specify the file path

$file = "C:\path\to\file.txt"



# Get the metadata properties you want to hash

$metadata = Get-ItemProperty -Path $file | Select-Object -Property Name, Length, LastWriteTime



# Convert the metadata to JSON format

$jsonMetadata = $metadata | ConvertTo-Json



# Calculate the hash of the JSON metadata

$hash = $jsonMetadata | Get-FileHash -Algorithm SHA256



# Output the hash value

$hash.Hash

In this example, the script retrieves specific metadata properties (Name, Length, LastWriteTime) of the file using Get-ItemProperty and pipes them to ConvertTo-Json to convert them into JSON format. Then, the JSON metadata is passed to Get-FileHash along with the desired hash algorithm (in this case, SHA256) to calculate the hash value. Finally, the hash value is displayed.

You can customize the metadata properties to include in the hash calculation by modifying the Select-Object cmdlet. Additionally, you can choose a different hash algorithm by changing the parameter passed to Get-FileHash.

Note that hashing metadata alone does not guarantee the integrity of the file content. If you need to ensure the integrity of the entire file, including its content, you should hash the entire file content, not just the metadata.