#328 Decrypt base64 encoded SOPS encrypted secrets #328

Kustomize-controller can currently decrypt SOPS encrypted files - but
whole files only.

Kubernetes Secrets are base64 encoded, therefore when a SOPS encrypted
file, is added as base64 encoded data to a Kubernetes Secret, it is not
decrypted.

Signed-off-by: Bob Rohan <bob.rohan@hodge.co.uk>

Author: bob.rohan

controllers/kustomization_decryptor.go

@@ -19,6 +19,7 @@ package controllers
 import (
 	"bytes"
 	"context"
+	"encoding/base64"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -75,6 +76,61 @@ func (kd *KustomizeDecryptor) Decrypt(res *resource.Resource) (*resource.Resourc
 		return nil, err
 	}
 
+	if res.GetKind() == "Secret" {
+
+		dataMap := res.GetDataMap()
+
+		for key, value := range dataMap {
+
+			data, err := base64.StdEncoding.DecodeString(value)
+			if err != nil {
+				fmt.Println("Base64 Decode: %w", err)
+			}
+
+			if kd.kustomization.Spec.Decryption != nil && kd.kustomization.Spec.Decryption.Provider == DecryptionProviderSOPS &&
+				bytes.Contains(data, []byte("sops")) && bytes.Contains(data, []byte("ENC[")) {
+
+				store := common.StoreForFormat(formats.Yaml)
+
+				tree, err := store.LoadEncryptedFile(data)
+				if err != nil {
+					return nil, fmt.Errorf("LoadEncryptedFile: %w", err)
+				}
+
+				metadataKey, err := tree.Metadata.GetDataKeyWithKeyServices(
+					[]keyservice.KeyServiceClient{
+						intkeyservice.NewLocalClient(intkeyservice.NewServer(false, kd.homeDir, kd.ageIdentities)),
+					},
+				)
+
+				if err != nil {
+					if userErr, ok := err.(sops.UserError); ok {
+						err = fmt.Errorf(userErr.UserError())
+					}
+					return nil, fmt.Errorf("GetDataKey: %w", err)
+				}
+
+				cipher := aes.NewCipher()
+				if _, err := tree.Decrypt(metadataKey, cipher); err != nil {
+					return nil, fmt.Errorf("AES decrypt: %w", err)
+				}
+
+				binaryStore := common.StoreForFormat(formats.Binary)
+
+				out, err := binaryStore.EmitPlainFile(tree.Branches)
+				if err != nil {
+					return nil, fmt.Errorf("EmitPlainFile: %w", err)
+				}
+
+				dataMap[key] = base64.StdEncoding.EncodeToString(out)
+			}
+		}
+
+		res.SetDataMap(dataMap)
+
+		return res, nil
+	}
+
 	if kd.kustomization.Spec.Decryption != nil && kd.kustomization.Spec.Decryption.Provider == DecryptionProviderSOPS &&
 		bytes.Contains(out, []byte("sops:")) && bytes.Contains(out, []byte("mac: ENC[")) {
 		store := common.StoreForFormat(formats.Yaml)