Decrypt base64 encoded SOPS encrypted secrets

Signed-off-by: Bob Rohan <bob.rohan@hodge.co.uk>
fluxcd · Apr 28, 2021 · a77ea03 · a77ea03
1 parent 1ba5d2b
commit a77ea03
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Showing 6 changed files with 164 additions and 33 deletions.
diff --git a/controllers/kustomization_controller_sops_test.go b/controllers/kustomization_controller_sops_test.go
@@ -18,6 +18,7 @@ package controllers
 
 import (
 	"context"
+	"encoding/base64"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -95,10 +96,19 @@ var _ = Describe("KustomizationReconciler", func() {
 			Expect(err).ToNot(HaveOccurred())
 			ageKey, err := ioutil.ReadFile("testdata/sops/age.txt")
 			Expect(err).ToNot(HaveOccurred())
+			dayKey, err := ioutil.ReadFile("testdata/sops/day.txt.encrypted")
+			Expect(err).ToNot(HaveOccurred())
+
 			sopsSecretKey := types.NamespacedName{
 				Name:      "sops-" + randStringRunes(5),
 				Namespace: namespace.Name,
 			}
+
+			sopsEncodedSecretKey := types.NamespacedName{
+				Name:      "sops-encoded-" + randStringRunes(5),
+				Namespace: namespace.Name,
+			}
+
 			sopsSecret := &corev1.Secret{
 				ObjectMeta: metav1.ObjectMeta{
 					Name:      sopsSecretKey.Name,
@@ -109,7 +119,20 @@ var _ = Describe("KustomizationReconciler", func() {
 					"age.agekey": string(ageKey),
 				},
 			}
+
+			sopsEncodedSecret := &corev1.Secret{
+				ObjectMeta: metav1.ObjectMeta{
+					Name:      sopsEncodedSecretKey.Name,
+					Namespace: sopsEncodedSecretKey.Namespace,
+				},
+				StringData: map[string]string{
+					// base64.StdEncoding.EncodeToString replicates kustomize.secretGenerator
+					"day.dayKey": base64.StdEncoding.EncodeToString(dayKey),
+				},
+			}
+
 			Expect(k8sClient.Create(context.Background(), sopsSecret)).To(Succeed())
+			Expect(k8sClient.Create(context.Background(), sopsEncodedSecret)).To(Succeed())
 
 			kustomizationKey := types.NamespacedName{
 				Name:      "sops-" + randStringRunes(5),
@@ -158,6 +181,10 @@ var _ = Describe("KustomizationReconciler", func() {
 			var ageSecret corev1.Secret
 			Expect(k8sClient.Get(context.TODO(), types.NamespacedName{Name: "sops-age", Namespace: namespace.Name}, &ageSecret)).To(Succeed())
 			Expect(ageSecret.Data["secret"]).To(Equal([]byte(`my-sops-age-secret`)))
+
+			var daySecret corev1.Secret
+			Expect(k8sClient.Get(context.TODO(), types.NamespacedName{Name: "sops-day", Namespace: namespace.Name}, &daySecret)).To(Succeed())
+			Expect(string(daySecret.Data["secret"])).To(Equal("day=Tuesday\n"))
 		})
 	})
 })
diff --git a/controllers/kustomization_decryptor.go b/controllers/kustomization_decryptor.go
@@ -19,6 +19,7 @@ package controllers
 import (
 	"bytes"
 	"context"
+	"encoding/base64"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -75,47 +76,103 @@ func (kd *KustomizeDecryptor) Decrypt(res *resource.Resource) (*resource.Resourc
 		return nil, err
 	}
 
-	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)
+	if kd.kustomization.Spec.Decryption != nil && kd.kustomization.Spec.Decryption.Provider == DecryptionProviderSOPS {
 
-		tree, err := store.LoadEncryptedFile(out)
-		if err != nil {
-			return nil, fmt.Errorf("LoadEncryptedFile: %w", err)
-		}
+		if bytes.Contains(out, []byte("sops:")) && bytes.Contains(out, []byte("mac: ENC[")) {
+			store := common.StoreForFormat(formats.Yaml)
 
-		key, 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())
+			tree, err := store.LoadEncryptedFile(out)
+			if err != nil {
+				return nil, fmt.Errorf("LoadEncryptedFile: %w", err)
 			}
-			return nil, fmt.Errorf("GetDataKey: %w", err)
-		}
 
-		cipher := aes.NewCipher()
-		if _, err := tree.Decrypt(key, cipher); err != nil {
-			return nil, fmt.Errorf("AES decrypt: %w", err)
-		}
+			key, 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)
+			}
 
-		data, err := store.EmitPlainFile(tree.Branches)
-		if err != nil {
-			return nil, fmt.Errorf("EmitPlainFile: %w", err)
-		}
+			cipher := aes.NewCipher()
+			if _, err := tree.Decrypt(key, cipher); err != nil {
+				return nil, fmt.Errorf("AES decrypt: %w", err)
+			}
 
-		jsonData, err := yaml.YAMLToJSON(data)
-		if err != nil {
-			return nil, fmt.Errorf("YAMLToJSON: %w", err)
-		}
+			data, err := store.EmitPlainFile(tree.Branches)
+			if err != nil {
+				return nil, fmt.Errorf("EmitPlainFile: %w", err)
+			}
+
+			jsonData, err := yaml.YAMLToJSON(data)
+			if err != nil {
+				return nil, fmt.Errorf("YAMLToJSON: %w", err)
+			}
+
+			err = res.UnmarshalJSON(jsonData)
+			if err != nil {
+				return nil, fmt.Errorf("UnmarshalJSON: %w", err)
+			}
+			return res, nil
+
+		} else 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 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
 
-		err = res.UnmarshalJSON(jsonData)
-		if err != nil {
-			return nil, fmt.Errorf("UnmarshalJSON: %w", err)
 		}
-		return res, nil
 	}
 	return nil, nil
 }

diff --git a/controllers/testdata/sops/day.txt b/controllers/testdata/sops/day.txt
@@ -0,0 +1 @@
+day=Tuesday
diff --git a/controllers/testdata/sops/day.txt.encrypted b/controllers/testdata/sops/day.txt.encrypted
@@ -0,0 +1,20 @@
+{
+	"data": "ENC[AES256_GCM,data:YWPHPTVOCWivqZu0,iv:tLqbJD/KN2BchlAz1mnf4FtMY+SP5hiBYJP6dHy8gtc=,tag:Aj9T0Q7y9baA84EfEt8MfQ==,type:str]",
+	"sops": {
+		"kms": null,
+		"gcp_kms": null,
+		"azure_kv": null,
+		"hc_vault": null,
+		"lastmodified": "2021-04-27T20:27:20Z",
+		"mac": "ENC[AES256_GCM,data:1OqDvIaUpOKFa1vsa6nc+GHIvsxwQ3JhJsDTp+Yl2r8y0+n0VUbCm9FyqVvq8ur3Y3NyZfX+7FL6HxgTN0RnSMdwK1X16ioGWBk4CM3K7W8tyY7gmhddsuJqSDZdV7Hr2s7FB6LZJAHWO9vTn9zXM75Ef0B5yuOgzp29LmIhCK4=,iv:8ozNZ7IgDub2vICSzHWcAdx7/sVEoe8YayXYrAkN0BM=,tag:UwE0b6eTpA9uir+4Mwed7g==,type:str]",
+		"pgp": [
+			{
+				"created_at": "2021-04-27T20:27:20Z",
+				"enc": "-----BEGIN PGP MESSAGE-----\n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\n=1o9a\n-----END PGP MESSAGE-----\n",
+				"fp": "35C1A64CD7FC0AB6EB66756B2445463C3234ECE1"
+			}
+		],
+		"encrypted_regex": "^(data|stringData)$",
+		"version": "3.6.0"
+	}
+}
diff --git a/controllers/testdata/sops/secret.day.yaml b/controllers/testdata/sops/secret.day.yaml
@@ -0,0 +1,7 @@
+apiVersion: v1
+data:
+  secret: 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
+kind: Secret
+metadata:
+  creationTimestamp: null
+  name: sops-day
diff --git a/docs/spec/v1beta1/kustomization.md b/docs/spec/v1beta1/kustomization.md
@@ -962,6 +962,25 @@ spec:
       name: sops-age
 ```
 
+### Kustomize secretGenerator
+
+`sops` encrypted data can be stored as a base64 encoded Secret, which enables use of kustomize secretGenerator as follows.
+
+```console
+$ echo "day=Tuesday" | sops -e /dev/stdin > day.txt.encrypted
+$ cat <<EOF > kustomization.yaml
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+secretGenerator:
+ - name: day-secret
+   files:
+   - ./day.txt.encrypted
+EOF
+```
+
+Commit and push `day.txt.encrypted` and `kustomization.yaml` to Git.
+
 ## Status
 
 When the controller completes a Kustomization apply, reports the result in the `status` sub-resource.