CAAI

Verifying Image Contents using OpenSSL and Public Key

In this guide, we'll walk through the process of verifying the contents of an image file using the command line, OpenSSL, and your public key.

Prerequisites

Before we begin, ensure you have the following:

• The image file you want to verify (image.jpg)
• Your public key (public.pem)
• OpenSSL installed on your system

Steps

1. Convert Image to Binary

   Start by converting the image file to binary. You can achieve this using the xxd command:

   xxd -p image.jpg > image.bin
   

2. Verify the Image

   Next, verify the image using OpenSSL and your public key:

   openssl dgst -sha256 -verify public.pem -signature image.bin.sha256 image.bin

   This command will verify the image contents using your public key.