feat: Add PGP encryption support

cmd/stbak/cmd/archive.go

@@ -17,6 +17,7 @@ import (
 	"strconv"
 
 	"filippo.io/age"
+	"github.com/ProtonMail/go-crypto/openpgp"
 	"github.com/andybalholm/brotli"
 	"github.com/dsnet/compress/bzip2"
 	"github.com/klauspost/compress/zstd"
@@ -471,6 +472,8 @@ func addSuffix(name string, compressionFormat string, encryptionFormat string) (
 	switch encryptionFormat {
 	case encryptionFormatAgeKey:
 		name += encryptionFormatAgeSuffix
+	case encryptionFormatPGPKey:
+		name += encryptionFormatPGPSuffix
 	case compressionFormatNoneKey:
 	default:
 		return "", errUnsupportedEncryptionFormat
@@ -492,6 +495,13 @@ func encrypt(
 		}
 
 		return age.Encrypt(dst, recipient)
+	case encryptionFormatPGPKey:
+		recipient, err := openpgp.ReadKeyRing(bytes.NewBuffer(pubkey))
+		if err != nil {
+			return nil, err
+		}
+
+		return openpgp.Encrypt(dst, recipient, nil, nil, nil)
 	case encryptionFormatNoneKey:
 		return noop.AddClose(dst), nil
 	default:
@@ -525,6 +535,27 @@ func encryptString(
 			return "", err
 		}
 
+		return base64.StdEncoding.EncodeToString(out.Bytes()), nil
+	case encryptionFormatPGPKey:
+		recipient, err := openpgp.ReadKeyRing(bytes.NewBuffer(pubkey))
+		if err != nil {
+			return "", err
+		}
+
+		out := &bytes.Buffer{}
+		w, err := openpgp.Encrypt(out, recipient, nil, nil, nil)
+		if err != nil {
+			return "", err
+		}
+
+		if _, err := io.WriteString(w, src); err != nil {
+			return "", err
+		}
+
+		if err := w.Close(); err != nil {
+			return "", err
+		}
+
 		return base64.StdEncoding.EncodeToString(out.Bytes()), nil
 	case encryptionFormatNoneKey:
 		return src, nil

cmd/stbak/cmd/recovery_index.go

@@ -416,6 +416,8 @@ func removeSuffix(name string, compressionFormat string, encryptionFormat string
 	switch encryptionFormat {
 	case encryptionFormatAgeKey:
 		name = strings.TrimSuffix(name, encryptionFormatAgeSuffix)
+	case encryptionFormatPGPKey:
+		name = strings.TrimSuffix(name, encryptionFormatPGPSuffix)
 	case encryptionFormatNoneKey:
 	default:
 		return "", errUnsupportedEncryptionFormat

cmd/stbak/cmd/root.go

@@ -44,6 +44,9 @@ const (
 
 	encryptionFormatAgeKey    = "age"
 	encryptionFormatAgeSuffix = ".age"
+
+	encryptionFormatPGPKey    = "pgp"
+	encryptionFormatPGPSuffix = ".pgp"
 )
 
 var (
@@ -52,7 +55,7 @@ var (
 	errUnknownCompressionFormat     = errors.New("unknown compression format")
 	errUnsupportedCompressionFormat = errors.New("unsupported compression format")
 
-	knownEncryptionFormats = []string{encryptionFormatNoneKey, encryptionFormatAgeKey}
+	knownEncryptionFormats = []string{encryptionFormatNoneKey, encryptionFormatAgeKey, encryptionFormatPGPKey}
 
 	errUnknownEncryptionFormat     = errors.New("unknown encryption format")
 	errUnsupportedEncryptionFormat = errors.New("unsupported encryption format")

go.mod

@@ -24,6 +24,7 @@ require (
 )
 
 require (
+	github.com/ProtonMail/go-crypto v0.0.0-20211112122917-428f8eabeeb3 // indirect
 	github.com/fsnotify/fsnotify v1.5.1 // indirect
 	github.com/gofrs/uuid v3.2.0+incompatible // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect

go.sum

@@ -54,6 +54,8 @@ github.com/Masterminds/goutils v1.1.0/go.mod h1:8cTjp+g8YejhMuvIA5y2vz3BpJxksy86
 github.com/Masterminds/semver v1.5.0/go.mod h1:MB6lktGJrhw8PrUyiEoblNEGEQ+RzHPF078ddwwvV3Y=
 github.com/Masterminds/sprig v2.22.0+incompatible/go.mod h1:y6hNFY5UBTIWBxnzTeuNhlNS5hqE0NB0E6fgfo2Br3o=
 github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
+github.com/ProtonMail/go-crypto v0.0.0-20211112122917-428f8eabeeb3 h1:XcF0cTDJeiuZ5NU8w7WUDge0HRwwNRmxj/GGk6KSA6g=
+github.com/ProtonMail/go-crypto v0.0.0-20211112122917-428f8eabeeb3/go.mod h1:z4/9nQmJSSwwds7ejkxaJwO37dru3geImFUdJlaLzQo=
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/andybalholm/brotli v1.0.4 h1:V7DdXeJtZscaqfNuAdSRuRFzuiKlHSC/Zh3zl9qY3JY=
@@ -462,6 +464,7 @@ golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20191122220453-ac88ee75c92c/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/crypto v0.0.0-20210322153248-0c34fe9e7dc2/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
 golang.org/x/crypto v0.0.0-20210817164053-32db794688a5 h1:HWj/xjIHfjYU5nVXpTM0s39J9CbLn7Cc5a7IC5rwsMQ=
 golang.org/x/crypto v0.0.0-20210817164053-32db794688a5/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=