README.md

AWS KMS

AWS KMS using envelope encryption with 256-bit AES in Galois/Counter Mode (GCM).

Quick Start

Sample Terraform code is available in testing/terraform/awskms to try this provider with AWS KMS.

Example

package main

import (
	"context"

	"github.com/aws/aws-sdk-go-v2/config"
	"github.com/aws/aws-sdk-go-v2/service/kms"

	"github.com/bincyber/go-sqlcrypter"
	"github.com/bincyber/go-sqlcrypter/providers/awskms"
)

func main() {
	cfg, err := config.LoadDefaultConfig(context.Background())
	if err != nil {
		// handle error
	}

	client := kms.NewFromConfig(cfg)

	kmsCrypter, err := awskms.New(context.Background(), client, "alias/sqlcrypter")
	if err != nil {
		//handle error
	}

	sqlcrypter.Init(kmsCrypter)
}

Envelope Encryption

KMSCrypter uses envelope encryption. When awskms.New() is called, a request is made to the the KMS GenerateDataKey API to retrieve a 256-bit symmetric data encryption key (DEK). This DEK is used to encrypt data using AES GCM instead of calling the KMS Encrypt and Decrypt APIs every time. The encrypted DEK is stored alongside the ciphertext. To decrypt previous DEKs stored alongside ciphertext, a request is made to the KMS Decrypt API. The decrypted DEK is then cached in memory to avoid repetitive API calls to KMS.

Testing

nsmith/local-kms is used to help with testing. The seed file used is located in testing/seed.yaml.