Generate SHA256 RSA Signature with PKCS1 in Go

Learn how to create a secure `SHA256 RSA` signature using `PKCS1 padding` in `GoLang`. Follow our step-by-step guide to implement RSA signing and verification.
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How to Generate SHA256 RSA Signature with PKCS1 Padding in GoLang

In today's digital world, ensuring data integrity and authenticity is crucial, especially for sensitive operations like payments. One effective way to achieve this is using RSA (Rivest-Shamir-Adleman) encryption combined with SHA256 hashing. This guide will show you how to generate a SHA256 RSA signature with PKCS1 padding in GoLang, step-by-step.

Understanding the Problem

When working with APIs or secure services, you often need to sign your requests to affirm their integrity and authenticity. For this process, you typically need:

A strong encryption algorithm (like RSA).

A secure hash function (like SHA256).

A standardized padding scheme (like PKCS1).

In this guide, we will create a secure signature using these components and outline the necessary implementation in GoLang.

Setting Up

Prerequisites

GoLang installed on your machine.

Basic familiarity with Go programming.

Understanding of RSA keys and how they work.

Generating RSA Keys

Before we can sign any content, we need to generate RSA keys. We'll create a private key that is kept confidential, and a public key that will be distributed as needed.

Implementing the Solution

1. Code Structure

We'll work with a simple GoLang application that will hash our input data, sign it with the RSA private key, and then verify the signature using the RSA public key.

Here’s the complete code structure:

[[See Video to Reveal this Text or Code Snippet]]

2. Explanation of the Code

Main Function: This is where the execution starts. We call functions to get keys, generate a hash sum, sign it, and verify the signature.

getKeys(): This function reads the private key from a PEM file, decodes it, and returns both the private and public keys.

getRequestHashSum(): This prepares a hashed version of the data that will be signed. Here we use SHA256 to hash the data.

sign(): This function generates the signature using the private key and the hashed data using the PKCS1v15 signing method.

verify(): This confirms the integrity of the signed data. It checks that the signature matches the original data and was created with the corresponding private key.

3. Compiling and Running

To run this code, save it in a file named main.go, ensuring that you have your privateKey.pem ready in the same directory. Open your terminal and run:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Using GoLang to generate a SHA256 RSA signature with PKCS1 padding is straightforward with the right libraries and functions. This method not only secures your data but also establishes trust between parties in any communication or transaction.

By implementing this solution, you can confidently handle sensitive data, ensuring both integrity and authenticity.

If you have any questions or need further clarification, feel free to reach out in the comments below!