How to add MD5 hash toa PowerShell file dump - powershell

Question

Looking for a line to add that pulls the file information as below but includes an MD5 hash
It can be from certutil, but there is not a means to download that module so looking for a means that uses PowerShell without an additional update of PowerShell.
We are looking to compare two disks for missing files even when the file might be located in an alternate location.
cls
$filPath="G:/"
Set-Location -path $filPath
Get-ChildItem -Path $filPath -recurse |`
foreach-object{
$Item=$_
$Path =$_.FullName
$ParentS=($_.FullName).split("/")
$Parent=$ParentS[#($ParentS.Length-2)]
$Folder=$_.PSIsContainer
#$Age=$_.CreationTime
#$Age=$_.ModifiedDate
$Modified=$_.LastWriteTime
$Type=$_.Extension
$Path | Select-Object `
#{n="Name";e={$Item}},`
#{n="LastModified";e={$Modified}},`
#{n="Extension";e={$Type}},`
#{n="FolderName";e={if($Parent){$Parent}else{$Parent}}},`
#{n="filePath";e={$Path}}`
} | Export-csv Q:/lpdi/fileDump.csv -NoTypeInformation
Possible answer here: (Thanks Guenther)
#{name="Hash";expression={(Get-FileHash -Algorithm MD5 -Path $Path).hash}}
In this script it meets the filehash condition along with the name of the file which allows a way to find the file on the folder and know it matches another one in another location based on the hash.
I'm not sure what happens on the file hash itself. If it includes the name of the file, the hash will be different. If it is only the file itself and the path doesn't matter, it should meet the requirement. I'm not sure how to include it in the code above however

Answer 1

Your code could be simplified so you don't need all those 'in-between' variables.
Also, the path separator character in Windows is a backslash (\), not a forward slash (/) which makes this part of your code $ParentS=($_.FullName).split("/") not doing what you expect from it.
Try
$SourcePath = 'G:\'
Get-ChildItem -Path $SourcePath -File -Recurse | ForEach-Object {
# remove the next line if you do not want console output
Write-Host "Processing file '$($_.FullName)'.."
$md5 = ($_ | Get-FileHash -Algorithm MD5).Hash
$_ | Select-Object #{Name = 'Name'; Expression = { $_.Name }},
#{Name = 'LastModified'; Expression = { $_.LastWriteTime }},
#{Name = 'Extension'; Expression = { $_.Extension }},
#{Name = 'FolderName'; Expression = { $_.Directory.Name }},
#{Name = 'FilePath'; Expression = { $_.FullName }},
#{Name = 'FileHash'; Expression = { $md5 }}
} | Export-Csv -Path 'Q:/lpdi/fileDump.csv' -NoTypeInformation
Because getting hash values is a time consuming process I've added a Write-Host line, so you know the script did not 'hang'..

Answer 2

Edit: Okay so, here is my workaround as promised.
Before we start, requirements are:
Have python 3.8 or above installed and registered in windows PATH
edit the ps1 file variables accordingly
edit the python file variables accordingly
bypass powershell script execution policies
There are 4 files in the working directory (different from your target directory):
addMD5.ps1 (static)
addMD5.py (static)
fileDump-original.csv (auto-generated)
fileDump-modified.csv (auto-generated)
Here are the contents of those 4 files:
addMD5.ps1
$targetDir="C:\Users\USERname4\Desktop\myGdrive"
$workingDir="C:\Users\USERname4\Desktop\myWorkingDir"
$pythonName="addMD5.py"
$exportName = "fileDump-original.csv"
Set-Location -path $workingDir
if (Test-Path $exportName)
{
Remove-Item $exportName
}
Get-ChildItem -Path $targetDir -recurse |`
foreach-object{
$Item=$_
$Path =$_.FullName
$ParentS=($_.FullName).split("/")
$Parent=$ParentS[#($ParentS.Length-2)]
$Folder=$_.PSIsContainer
#$Age=$_.CreationTime
#$Age=$_.ModifiedDate
$Modified=$_.LastWriteTime
$Type=$_.Extension
$Path | Select-Object `
#{n="Name";e={$Item}},`
#{n="LastModified";e={$Modified}},`
#{n="Extension";e={$Type}},`
#{n="FolderName";e={if($Parent){$Parent}else{$Parent}}},`
#{n="filePath";e={$Path}}`
} | Export-csv $exportName -NoTypeInformation
python $pythonName
addMD5.py
import os, hashlib
def file_len(fname):
with open(fname) as fp:
for i, line in enumerate(fp):
pass
return i + 1
def read_nth(fname,intNth):
with open(fname) as fp:
for i, line in enumerate(fp):
if i == (intNth-1):
return line
def getMd5(fname):
file_hash = hashlib.md5()
with open(fname, "rb") as f:
chunk = f.read(8192)
while chunk:
file_hash.update(chunk)
chunk = f.read(8192)
return file_hash.hexdigest()
file1name = "fileDump-original.csv"
file2name = "fileDump-modified.csv"
try:
os.remove(file2name)
except:
pass
file2 = open(file2name , "w")
for linenum in range(file_len(file1name)):
if (linenum+1) == 1:
file2.write(read_nth(file1name,linenum+1).strip()+',"md5"\n')
else:
innerfilename = read_nth(file1name,linenum+1).split(",")[4].strip()[1:-1]
file2.write(read_nth(file1name,linenum+1).strip()+',"'+getMd5(innerfilename)+'"\n')
file2.close()
fileDump-original.csv
"Name","LastModified","Extension","FolderName","filePath"
"test1.txt","20-Jun-21 12:50:44 PM",".txt","C:\Users\USERname4\Desktop\myGdrive\test1.txt","C:\Users\USERname4\Desktop\myGdrive\test1.txt"
"test2.txt","20-Jun-21 12:50:37 PM",".txt","C:\Users\USERname4\Desktop\myGdrive\test2.txt","C:\Users\USERname4\Desktop\myGdrive\test2.txt"
fileDump-modified.csv
"Name","LastModified","Extension","FolderName","filePath","md5"
"test1.txt","20-Jun-21 12:50:44 PM",".txt","C:\Users\USERname4\Desktop\myGdrive\test1.txt","C:\Users\USERname4\Desktop\myGdrive\test1.txt","d659c1bc0a3010b0bdd45d9a8fee3196"
"test2.txt","20-Jun-21 12:50:37 PM",".txt","C:\Users\USERname4\Desktop\myGdrive\test2.txt","C:\Users\USERname4\Desktop\myGdrive\test2.txt","d55749658669d28f8549d94cd01b72ba"