Can I check the contents of encrypted zip-archive without using password? - windows

Question

I've encrypted .zip archive with some files. Later archive contents must be checked by someone who doesn't know encryption password. Is there any way to do this in powershell?
Ubuntu has zip -sf myfile.zip command but I couldn't find any simular in powershell.

Answer 1

If you're just looking to list the zip contents, then this function will do. As for extracting the Zip contents, ZipArchive does not support encrypted Zips as of today. There are third party PowerShell Modules as well as libraries that can do this though.
function Get-ZipContent {
[CmdletBinding()]
param(
[Parameter(ParameterSetName = 'Path', Position = 0, Mandatory, ValueFromPipeline)]
[string[]] $Path,
[Parameter(ParameterSetName = 'LiteralPath', Mandatory, ValueFromPipelineByPropertyName)]
[Alias('PSPath')]
[string[]] $LiteralPath,
[Parameter()]
[switch] $Force
)
begin {
Add-Type -AssemblyName System.IO.Compression
}
process {
try {
$arguments = switch($PSCmdlet.ParameterSetName) {
Path { $Path, $Force.IsPresent, $false }
LiteralPath { $LiteralPath, $Force.IsPresent, $true }
}
foreach($item in $ExecutionContext.InvokeProvider.Item.Get.Invoke($arguments)) {
try {
$fs = $item.OpenRead()
$zip = [IO.Compression.ZipArchive]::new($fs, [IO.Compression.ZipArchiveMode]::Read)
foreach($entry in $zip.Entries) {
$entry.PSObject.Properties.Add([psnoteproperty]::new('Source', $item.FullName))
$entry
}
}
catch {
$PSCmdlet.WriteError($_)
}
finally {
$zip, $fs | ForEach-Object Dispose
}
}
}
catch {
$PSCmdlet.WriteError($_)
}
}
}
Usage:
PS ..\pwsh> Get-ZipContent path\to\myfolder\*.zip
PS ..\pwsh> Get-ChildItem path\to\things -Recurse -Filter *.zip | Get-ZipContent
To further expand the usage since it seems not quite clear:
# load the function in memory:
PS ..\pwsh> . ./theFunctionisHere.ps1
# call the function giving it a path to a zip:
PS ..\pwsh> Get-ZipContent ./thing.zip
Source : path/to/pwsh/thing.zip
Archive : System.IO.Compression.ZipArchive
Crc32 : 0
IsEncrypted : True
CompressedLength : 165
ExternalAttributes : 32
Comment :
FullName : other thing.txt
LastWriteTime : 10/29/2022 10:31:30 AM -03:00
Length : 446
Name : other thing.txt
Source : path/to/pwsh/thing.zip
Archive : System.IO.Compression.ZipArchive
Crc32 : 0
IsEncrypted : True
CompressedLength : 165
ExternalAttributes : 32
Comment :
FullName : thing.txt
LastWriteTime : 10/29/2022 10:31:30 AM -03:00
Length : 446
Name : thing.txt