/
kmsutils.go
56 lines (48 loc) · 1.25 KB
/
kmsutils.go
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package common
import (
"context"
"encoding/base64"
"os"
"strings"
cloudkms "cloud.google.com/go/kms/apiv1"
kmspb "google.golang.org/genproto/googleapis/cloud/kms/v1"
)
type KMSClient struct {
client *cloudkms.KeyManagementClient
}
func NewKMSClient() (*KMSClient, error) {
client, err := cloudkms.NewKeyManagementClient(context.Background())
if err != nil {
return nil, err
}
return &KMSClient{client: client}, nil
}
// Takes base64 ciphertext and decodes it.
func prepareSecret(ciphertext string) ([]byte, error) {
return base64.StdEncoding.DecodeString(strings.TrimPrefix(ciphertext, "cloudkms://"))
}
func (kms *KMSClient) DecryptEnvVar(keyName, envVar string) (string, error) {
v := os.Getenv(envVar)
if !strings.HasPrefix(v, "cloudkms://") {
return v, nil
}
ciphertext, err := prepareSecret(v)
if err != nil {
return "", err
}
return kms.DecryptSymmetric(keyName, ciphertext)
}
func (kms *KMSClient) DecryptSymmetric(keyName string, ciphertext []byte) (string, error) {
ctx := context.Background()
// Build the request.
req := &kmspb.DecryptRequest{
Name: keyName,
Ciphertext: ciphertext,
}
// Call the API.
resp, err := kms.client.Decrypt(ctx, req)
if err != nil {
return "", err
}
return string(resp.Plaintext), nil
}