Setting Default Server-Side Encryption for an Amazon S3 Bucket

The following example uses the PutBucketEncryption method to enable KMS server-side encryption on any objects added to myBucket.

The only exception is if the user configures their request to explicitly use server-side encryption. In that case, the specified encryption takes precedence.

Choose Copy to save the code locally.

Create the file set_default_encryption.go.

Import the required packages.

import (
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/s3"

    "fmt"
    "os"
)

Get the KMS key from the command line, where key is a KMS key ID as created in the Creating a CMK in AWS Key Management Service example, and set the bucket name.

if len(os.Args) != 2 {
    fmt.Println("You must supply a key")
    os.Exit(1)
}

key := os.Args[1]
bucket := "myBucket"

Create a session and Amazon S3 client.

sess := session.Must(session.NewSessionWithOptions(session.Options{
    SharedConfigState: session.SharedConfigEnable,
}))

svc := s3.New(sess)

Create the input for and call PutBucketEncryption, and display a success message.

defEnc := &s3.ServerSideEncryptionByDefault{KMSMasterKeyID: aws.String(key), SSEAlgorithm: aws.String(s3.ServerSideEncryptionAwsKms)}
rule := &s3.ServerSideEncryptionRule{ApplyServerSideEncryptionByDefault: defEnc}
rules := []*s3.ServerSideEncryptionRule{rule}
serverConfig := &s3.ServerSideEncryptionConfiguration{Rules: rules}
input := &s3.PutBucketEncryptionInput{Bucket: aws.String(bucket), ServerSideEncryptionConfiguration: serverConfig}
_, err := svc.PutBucketEncryption(input)
fmt.Println("Bucket " + bucket + " now has KMS encryption by default")

See the complete example on GitHub.