Posts tagged ‘MD5’

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 has been working with LaTeX for more than a decade. Besides TeX/LaTeX he likes to work with Python, Rasberry/Arduino and his digital camera.

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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 has been working with LaTeX for more than a decade. Besides TeX/LaTeX he likes to work with Python, Rasberry/Arduino and his digital camera.

More Posts - Website

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 has been working with LaTeX for more than a decade. Besides TeX/LaTeX he likes to work with Python, Rasberry/Arduino and his digital camera.

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