aes

AES Encryption/Decryption Example

This example demonstrates basic AES (Advanced Encryption Standard) GCM (Galois/Counter Mode) encryption and decryption using the aesgcm package.

Overview

The aes example showcases:

1. Defining a hexadecimal AES key.
2. Encrypting a plaintext byte slice ([]byte("0123456789abcdef")) using aesgcm.AESEncrypt.
3. Decrypting the resulting ciphertext using aesgcm.AESDecrypt with the same key.
4. Printing the decrypted data.

Code Walkthrough

Encrypting and Decrypting Data

package main

import (
	"encoding/hex"
	"fmt"

	aes "github.com/bsv-blockchain/go-sdk/primitives/aesgcm"
)

func main() {
	// Define an AES key (must be 16, 24, or 32 bytes for AES-128, AES-192, or AES-256 respectively)
	key, _ := hex.DecodeString("000102030405060708090a0b0c0d0e0f") // 16 bytes for AES-128

	plaintext := []byte("0123456789abcdef")

	// Encrypt the data
	encryptedData, err := aes.AESEncrypt(plaintext, key)
	if err != nil {
		fmt.Println("Encryption error:", err)
		return
	}
	fmt.Printf("Encrypted data (hex): %x\n", encryptedData)

	// Decrypt the data
	decryptedData, err := aes.AESDecrypt(encryptedData, key)
	if err != nil {
		fmt.Println("Decryption error:", err)
		return
	}
	fmt.Printf("Decrypted data: %s\n", decryptedData)
}

This section shows:

• Initialization of a 16-byte AES key.
• Encryption of a sample plaintext using aes.AESEncrypt. This function handles nonce generation and prepends it to the ciphertext.
• Decryption of the ciphertext using aes.AESDecrypt. This function extracts the nonce from the ciphertext and performs decryption.

Running the Example

To run this example:

go run aes.go

The output will show the hexadecimal representation of the encrypted data, followed by the successfully decrypted original message.

Note:

• The key used is hardcoded. In real applications, keys should be securely generated and managed.
• The aesgcm package uses AES in GCM mode, which provides both confidentiality and authenticity.
• The nonce is generated internally by AESEncrypt and prepended to the ciphertext. AESDecrypt expects this format.

Integration Steps

To use AES GCM encryption/decryption in your application:

For Encryption:

1. Obtain or generate a secure AES key of appropriate length (16, 24, or 32 bytes).
2. Call ciphertext, err := aesgcm.AESEncrypt(plaintextBytes, key).
3. Store or transmit the ciphertext.

For Decryption:

1. Obtain the same AES key used for encryption.
2. Call plaintextBytes, err := aesgcm.AESDecrypt(ciphertext, key).
3. The plaintextBytes will contain the original data if decryption is successful.

Ensure proper key management practices are followed.

Additional Resources

For more information, see:

• Package Documentation - aesgcm
• NIST Special Publication 800-38D for GCM mode.