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How To: How and when to use CheckSum (MD5)

Summary

What is CheckSum?

A checksum is a string of numbers and letters used to uniquely identify a file. Checksum is most commonly used to verify if a copy of a file is identical to an original, such as downloaded copies of ArcGIS product installation or patch files.

How does CheckSum work?

A file is pushed through an algorithm, which outputs a unique alphanumeric string called a checksum, also known as a "hash". Different files, even those with minute differences, produce different checksum values.

There are multiple algorithms that can be used to produce a checksum value. The algorithm that Esri uses to provide checksum values is MD5. Other algorithms include SHA-1, SHA-256, and SHA-512.

Image of the process to verify the checksum of a file.

What circumstances would warrant verifying a CheckSum value?

Files may be changed during download, transmission, or storage. For example, if there is an issue with network connectivity at the time of download, the file may not download correctly. Issues with hard drive storage could also lead to file alteration.

Note:
CheckSum can be used to verify any type of file. The steps provided in this article are specific to installers and executable files.

Procedure

How to calculate the CheckSum of a file (Windows)

Note:
This procedure uses Windows PowerShell, included in Windows 7 and Windows Server 2008 R2. Versions of PowerShell for Windows XP, Windows Server 2003, Windows Vista and Windows Server 2008 are available for download for both 32-bit and 64-bit platforms.
  1. Open Windows PowerShell from the Windows menu.
Image of Windows Powershell
  1. Type Get-FileHash.
Image of the Windows Powershell Administrator pane
  1. Drag and drop the file to be verified from the local directory into the PowerShell window. If the file is stored on a network drive, open the file directory either via a UNC path or a mapped letter drive in Windows File Explorer, then drag and drop the file into the PowerShell window as shown below. In this example, the ArcGIS Pro 2.3 executable file is used.
Image of dragging and dropping the file from Windows File Explorer
  1. After the filename, press the spacebar and enter -Algorithm MD5 to ensure the MD5 algorithm is used. An example of the final command is displayed below, where <filepath> is the full path of the file. In this example, the path is 'C:\arcgis\ArcGISPro_23_167023.exe'.
Get-FileHash <filepath> -Algorithm MD5
  1. Press Enter. The output is the checksum value using the MD5 algorithm.
Image of the Windows Powershell Administrator pane showing the output checksum value
 
  1. Compare the output checksum value to the checksum values provided by Esri. Product downloads can be verified with the Downloads page of My Esri:
    1. Go to My Esri.
    2. Click My Organizations.
    3. Click Downloads.
    4. Select View Downloads for the appropriate product and version.
    5. In the Download Components tab, expand Product Components, and locate the appropriate product.
    6. Click Additional Information to display the listed checksum.
Image of My Esri Downloads

How to calculate the CheckSum of a file (Linux)

  1. Change the directory to the location of the file.
  2. Type md5sum then a space, followed by the full name of the file.
md5sum ArcGIS_Server_Linux_1061_164044.tar.gz
  1. Press Enter to execute the command. The output is the checksum value using the MD5 algorithm followed by the filename.
85bb36e13c3b00fabcd97ff3f244bd26  ArcGIS_Server_Linux_1061_164044.tar.gz
  1. Compare the output checksum value to the checksum values provided by Esri. Product downloads can be verified with the Downloads page of My Esri:
    1. Go to My Esri.
    2. Click My Organizations.
    3. Click Downloads.
    4. Select View Downloads for the appropriate product and version.
    5. In the Download Components tab, expand Product Components to locate the appropriate product.
    6. Click Additional Information to display the listed checksum.
Image of My Esri Downloads

Related Information

Last Published: 6/17/2021

Article ID: 000020408

Software: ArcGIS Data Store 10.9, 10.8.1, 10.8, 10.7.1, 10.7, 10.6.1, 10.6, 10.5.1, 10.5, 10.4.1, 10.4, 10.3.1, 10.3 Portal for ArcGIS 10.9, 10.8.1, 10.8, 10.7.1, 10.7, 10.6.1, 10.6, 10.5.1, 10.5, 10.4.1, 10.4, 10.3.1, 10.3, 10.2.2, 10.2.1, 10.2 ArcGIS Pro 2.8, 2.7.4, 2.7.3, 2.7.2, 2.7.1, 2.7, 2.6.6, 2.6.5, 2.6.4, 2.6.3, 2.6.2, 2.6.1, 2.6, 2.5.2, 2.5.1, 2.5, 2.4.3, 2.4.2, 2.4.1, 2.4, 2.3.3, 2.3.2, 2.3.1, 2.3, 2.2.4, 2.2.3, 2.2.2, 2.2.1, 2.2, 2.1.3, 2.1.2, 2.1.1, 2.1, 2.0.1, 2.0, 1.4.1, 1.4, 1.3.1, 1.3, 1.2