README.md

encrypt-decrypt

A personal study project in Go (v1.23) that demonstrates how to generate and manage HMAC keys, encrypt and decrypt messages using AES-GCM, and store data securely in a lightweight embedded database (buntdb).

Features

• Key Management:
  • Generate and store an HMAC key.
  • Retrieve the stored key via an API endpoint.
• Encryption/Decryption:
  • Encrypt a message using AES-GCM.
  • Decrypt a previously encrypted message.
• Lightweight Database:
  • Stores the HMAC key using buntdb.

Endpoints

1. POST /key

• Description: Generates a new HMAC key and stores it in the database.
• Response: 201 Created

  {
  "key": "0766ff57136f0d93328d990d57404b7dfbdac4a5fe350bbf8d3e9f108366599e"
  }

2. GET /key

• Description: Retrieves the stored HMAC key.
• Response:

  {
    "key": "a1b2c3d4e5f67890abcdef1234567890abcdef1234567890abcdef1234567890"
  }

3. POST /encrypt

• Description: Encrypts a given plaintext using AES-GCM.
• Request:

  {
    "text": "fabs"
  }

• Response:

  {
    "text_decrypted": "fabs",
    "text_encrypted": "kIQUVGVxJOGsSB2imBc48PJ+RcUg/UEteMX+0qberDM="
  }

4. POST /decrypt

• Description: Decrypts a previously encrypted message using AES-GCM.
• Request:

  {
    "text": "kIQUVGVxJOGsSB2imBc48PJ+RcUg/UEteMX+0qberDM="
  }

• Response:

  {
    "text_decrypted": "fabs",
    "text_encrypted": "kIQUVGVxJOGsSB2imBc48PJ+RcUg/UEteMX+0qberDM="
  }

Project Structure

encrypt-decrypt/
├── cmd/
│ └── main.go # Main file to start the server
├── internal/
│ ├── handler/ # Layer responsible for HTTP (controllers)
│ │ └── decrypt_handler.go
│ │ └── encrypt_handler.go
│ │ └── key_handler.go
│ ├── service/ # Business logic layer (use cases)
│ │ └── decrypt_service.go
│ │ └── encrypt_service.go
│ │ └── key_service.go
│ ├── repository/ # Data access layer
│ │ └── key_repo.go
│ └── entity/ # Domain entities layer
│ └── key.go
├── go.mod # Dependency management
└── go.sum

Requirements

• Go 1.23 or later
• buntdb library

Installation

1. Clone repository

git clone https://github.com/your-username/encrypt-decrypt.git
cd encrypt-decrypt

2. Install dependencies

go mod tidy

3. Run the application

go run cmd/main.go

How it works

1. Key Management:

• The POST /key endpoint generates a cryptographically secure HMAC key and stores it in buntdb.
• The GET /key endpoint retrieves this key for internal operations.

2. Encryption/Decryption:

• AES-GCM is used for encrypting and decrypting messages. This ensures authenticated encryption for message confidentiality and integrity.
• Encrypted messages are encoded in Base64 for easy handling.

3. Database:

• buntdb is used to persist the HMAC key. It provides a lightweight, in-memory database with ACID compliance

Example Usage

1. Generate a key:

curl -X POST http://localhost:8080/key

2.Retrieve the key:

curl http://localhost:8080/key

3. Encrypt a message:

curl -X POST -H "Content-Type: application/json" -d '{"text":"fabs"}' http://localhost:8080/encrypt

4.Decrypt a message:

curl -X POST -H "Content-Type: application/json" -d '{"text":"fabs"}' http://localhost:8080/decrypt

Author

Developed by Fabs.