Using Powershell to calculate/compare MD5 hashes

This entry is part 1 of 4 in the series MD 5 Calculation

Here’s some code to a) calculate a MD5 hash for a given file and b) to compare the hash with a MD5 provided in an external file. The scripts expects the MD5 file to have the same name, but MD5 extension. Credit goes to the friendly souls providing the original code, I just copied and pasted everything together.

The comparison is just visual, both MD5 hashes — the calculated and the provided one — are printed on the screen, it’s easily to extend it for an automated comparison.

# Reference: http://onlinemd5.com/
 
### Step A: Get the name of the file
# http://blogs.technet.com/b/heyscriptingguy/archive/2009/09/01/hey-scripting-guy-september-1.aspx
Function Get-FileName($initialDirectory)
{  
 [System.Reflection.Assembly]::LoadWithPartialName("System.windows.forms") |
Out-Null
 
 
$OpenFileDialog = New-Object System.Windows.Forms.OpenFileDialog
$OpenFileDialog.initialDirectory = $initialDirectory
$OpenFileDialog.filter = "All files (*.*)| *.*"
$OpenFileDialog.ShowDialog() | Out-Null
$OpenFileDialog.filename
} #end function Get-FileName
 
# *** Entry Point to Script ***
$file =  Get-FileName -initialDirectory "H:\MD5"
 
### Step B: Create a file handle from this string and calculate the MD5 sum
 
$filehandle = Get-ChildItem $file
 
# write-host "file: " $file
# write-host "DirectoryName: " $filehandle.DirectoryName
write-host "Name: " $filehandle.Name
# write-host "pure Name: " $filehandle.BaseName
 
# http://stackoverflow.com/questions/10521061/how-to-get-an-md5-checksum-in-powershell
$md5 = New-Object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider
$hash = [System.BitConverter]::ToString($md5.ComputeHash([System.IO.File]::ReadAllBytes($filehandle))).ToLower().Replace("-","")
 
write-host "Calculated Hashsum: "  $hash
 
### Step C: Get the MD5 sum from the MD5 sum file matching the other filename
 
$md5handle =  Get-ChildItem $($filehandle.DirectoryName + "\" + $filehandle.BaseName + ".md5")
$md5sum = [IO.File]::ReadAllText($md5handle)
 
write-host "Provided MD5        " $md5sum

Uwe

Uwe Ziegenhagen mag LaTeX und Python, auch gern in Kombination.

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Using Powershell to create MD5 files

This entry is part 2 of 4 in the series MD 5 Calculation

Following up on an article a few days ago here’s a script that creates a MD5 file.

# Uwe Ziegenhagen, 12.11.2014
# Reference: http://onlinemd5.com/
 
### Step A: Get the name of the file
# http://blogs.technet.com/b/heyscriptingguy/archive/2009/09/01/hey-scripting-guy-september-1.aspx
Function Get-FileName($initialDirectory)
{  
 [System.Reflection.Assembly]::LoadWithPartialName("System.windows.forms") | Out-Null
$OpenFileDialog = New-Object System.Windows.Forms.OpenFileDialog
$OpenFileDialog.initialDirectory = $initialDirectory
$OpenFileDialog.filter = "All files (*.*)| *.*"
$OpenFileDialog.ShowDialog() | Out-Null
$OpenFileDialog.filename
} #end function Get-FileName
 
# *** Entry Point to Script ***
$file =  Get-FileName -initialDirectory "C:\"
# write-host "file: " $file
 
### Step B: Create a file handle from this string and calculate the MD5 sum
$filehandle = Get-ChildItem $file
 
write-host "Filename: " $filehandle.Name
 
# http://stackoverflow.com/questions/10521061/how-to-get-an-md5-checksum-in-powershell
$md5 = New-Object -TypeName System.Security.Cryptography.MD5CryptoServiceProvider
$hash = [System.BitConverter]::ToString($md5.ComputeHash([System.IO.File]::ReadAllBytes($filehandle))).ToLower().Replace("-","")
 
write-host "Calculated Hashsum: "  $hash
 
### Step C: Write the MD5 sum from the MD5 sum file matching the other filename
$hash | out-file -FilePath $($filehandle.DirectoryName + "\" + $filehandle.BaseName + ".md5")

Uwe

Uwe Ziegenhagen mag LaTeX und Python, auch gern in Kombination.

Hat Dir dieser Beitrag geholfen und möchtest Du Dich dafür bedanken? Dann unterstütze doch vielleicht die Dingfabrik Köln e.V. mit einem kleinen Beitrag. Details zur Bezahlung findest Du unter Spenden für die Dingfabrik.

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Using Python to compute a MD5 Hash

This entry is part 3 of 4 in the series MD 5 Calculation

Here some Python code to calculate the MD5 hash for a given file:

# from http://www.pythoncentral.io/hashing-files-with-python/
import hashlib
 
hasher = hashlib.md5()
with open('e:/Mappe1.xlsx', 'rb') as afile:
    buf = afile.read()
    hasher.update(buf)
print(hasher.hexdigest())

Here the final script that provides the same functionality as the Powershell script I posted earlier today:

# http://www.pythoncentral.io/hashing-files-with-python/
import hashlib
import os
import codecs
 
hasher = hashlib.md5()
 
def calcHash(filename):
	print("Filename:   " + filename)
	with open(filename, 'rb') as afile:
		buf = afile.read()
		hasher.update(buf)
		print("Calculated: " + hasher.hexdigest())
		md5file = (os.path.splitext(filename)[0]) + ".md5"
		givenMD5 = codecs.open(md5file, "r", "utf-8-sig")
		print("Provided:   " + str(givenMD5.read()).lower())
 
calcHash("e:/Mappe1.xlsx")

Uwe

Uwe Ziegenhagen mag LaTeX und Python, auch gern in Kombination.

Hat Dir dieser Beitrag geholfen und möchtest Du Dich dafür bedanken? Dann unterstütze doch vielleicht die Dingfabrik Köln e.V. mit einem kleinen Beitrag. Details zur Bezahlung findest Du unter Spenden für die Dingfabrik.

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Creating MD5 files with Python

This entry is part 4 of 4 in the series MD 5 Calculation

Here’s the probably last part of this series, the missing piece showing the calculation of MD5 files with Python:

# http://www.pythoncentral.io/hashing-files-with-python/
import hashlib
import os
import codecs
 
hasher = hashlib.md5()
 
def calcHash(filename):
	print("Filename:   " + filename)
	with open(filename, 'rb') as afile:
		buf = afile.read()
		hasher.update(buf)
		print("Calculated: " + hasher.hexdigest())
		md5file = (os.path.splitext(filename)[0]) + ".md5"
		writeMD5 = codecs.open(md5file, "wb", "utf-8-sig")
		writeMD5.write(hasher.hexdigest())
 
calcHash("e:/arara.log")

Uwe

Uwe Ziegenhagen mag LaTeX und Python, auch gern in Kombination.

Hat Dir dieser Beitrag geholfen und möchtest Du Dich dafür bedanken? Dann unterstütze doch vielleicht die Dingfabrik Köln e.V. mit einem kleinen Beitrag. Details zur Bezahlung findest Du unter Spenden für die Dingfabrik.

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