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KBA80003: Checking File Integrity using HashCalc 2.0

Knowledge Base Article #:

80003

Applicable Versions:

N-central 6.5, 6.7, 7.x, 8.x, 9.x

Date Created/Updated:

April 27, 2011

Introduction

MD5 and SHA1 are algorithms that can be used to verify the integrity of any file. Comparing the expected SHA1 or MD5 value with the one that is calculated can be a way to verify whether the contents of the file have kept their integrity.

This article will provide instructions on how to use a program called HashCalc 2.0 to verify the file integrity of any file downloaded from our site or backup files generated by your server.

HashCalc 2.0 is available for free and can be downloaded from the HashCalc website: http://www.slavasoft.com/hashcalc/

Process

  1. Double-click on the HashCalc 2.0 icon.
  2. In HashCalc, browse to the location of the file you wish to check
  3. Select the desired algorithms to have output for.
  4. Click OK
  5. After a moment's calculation (which will vary depending on file size), HashCalc 2.0 will display a SHA1 hash value.

Example: 76ce6845f5fd2317a1e947aa45164e2032d710a4

This value is based upon the contents of the file. By comparing the SHA1 value generated to the SHA1 value provided, you can confirm whether or not the file has been corrupted during the download process.

If the SHA1 values are the same, the file is not corrupted; if the SHA1 values are different, then the file has become corrupted, and should be downloaded again.

When verifying backup files from the Central Server, the calculated SHA1 value for the backup file (*.tgz) should match the SHA1 value stored within the corresponding text file (*.SHA1).