From 3c002e993d21278c7f1b02c5c84a1167f20ed76e Mon Sep 17 00:00:00 2001
From: emersion <contact@emersion.fr>
Date: Thu, 11 Jan 2018 00:13:28 +0100
Subject: [PATCH] protonmail: use symetricallyEncrypt in Attachment.Encrypt

---
 protonmail/attachments.go | 18 ++++++------------
 protonmail/crypto.go      | 13 ++++++++++---
 protonmail/messages.go    |  2 +-
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/protonmail/attachments.go b/protonmail/attachments.go
index ab6f013..6427c16 100644
--- a/protonmail/attachments.go
+++ b/protonmail/attachments.go
@@ -82,19 +82,13 @@ func (att *Attachment) Encrypt(ciphertext io.Writer, signed *openpgp.Entity) (cl
 		return nil, errors.New("cannot encrypt attachment: no attachment key available")
 	}
 
-	encryptedData, err := packet.SerializeSymmetricallyEncrypted(ciphertext, att.unencryptedKey.CipherFunc, att.unencryptedKey.Key, config)
-	if err != nil {
-		return nil, err
+	// TODO: sign and store signature in att.Signature
+
+	hints := &openpgp.FileHints{
+		IsBinary: true,
+		FileName: att.Name,
 	}
-
-	// TODO: sign, see https://github.com/golang/crypto/blob/master/openpgp/write.go#L287
-
-	literalData, err := packet.SerializeLiteral(encryptedData, true, att.Name, 0)
-	if err != nil {
-		return nil, err
-	}
-
-	return literalData, nil
+	return symetricallyEncrypt(ciphertext, att.unencryptedKey, nil, hints, config)
 }
 
 // GetAttachment downloads an attachment's payload. The returned io.ReadCloser
diff --git a/protonmail/crypto.go b/protonmail/crypto.go
index ed17baf..7c76510 100644
--- a/protonmail/crypto.go
+++ b/protonmail/crypto.go
@@ -106,7 +106,7 @@ func generateUnencryptedKey(cipher packet.CipherFunction, config *packet.Config)
 	}, nil
 }
 
-func symetricallyEncrypt(ciphertext io.Writer, symKey *packet.EncryptedKey, signer *packet.PrivateKey, config *packet.Config) (plaintext io.WriteCloser, err error) {
+func symetricallyEncrypt(ciphertext io.Writer, symKey *packet.EncryptedKey, signer *packet.PrivateKey, hints *openpgp.FileHints, config *packet.Config) (plaintext io.WriteCloser, err error) {
 	// From https://github.com/golang/crypto/blob/master/openpgp/write.go#L172
 
 	encryptedData, err := packet.SerializeSymmetricallyEncrypted(ciphertext, symKey.CipherFunc, symKey.Key, config)
@@ -129,6 +129,10 @@ func symetricallyEncrypt(ciphertext io.Writer, symKey *packet.EncryptedKey, sign
 		}
 	}
 
+	if hints == nil {
+		hints = &openpgp.FileHints{}
+	}
+
 	w := encryptedData
 	if signer != nil {
 		// If we need to write a signature packet after the literal
@@ -136,8 +140,11 @@ func symetricallyEncrypt(ciphertext io.Writer, symKey *packet.EncryptedKey, sign
 		// encryptedData.
 		w = noOpCloser{encryptedData}
 	}
-
-	literalData, err := packet.SerializeLiteral(w, false, "", 0)
+	var epochSeconds uint32
+	if !hints.ModTime.IsZero() {
+		epochSeconds = uint32(hints.ModTime.Unix())
+	}
+	literalData, err := packet.SerializeLiteral(w, hints.IsBinary, hints.FileName, epochSeconds)
 	if err != nil {
 		return nil, err
 	}
diff --git a/protonmail/messages.go b/protonmail/messages.go
index b7550c4..fc9766b 100644
--- a/protonmail/messages.go
+++ b/protonmail/messages.go
@@ -302,7 +302,7 @@ func (set *MessagePackageSet) Encrypt(mimeType string, signed *openpgp.Entity) (
 	encoded := new(bytes.Buffer)
 	ciphertext := base64.NewEncoder(base64.StdEncoding, encoded)
 
-	cleartext, err := symetricallyEncrypt(ciphertext, key, signer, config)
+	cleartext, err := symetricallyEncrypt(ciphertext, key, signer, nil, config)
 	if err != nil {
 		return nil, err
 	}