Add a streaming api to KeyRing and SessionKey (#131)

* barebone streaming functionality * encryption needs to return a writecloser * added eof check * workaround for reader problem with copies * separate mobile wrappers from main api * add a clone in the read result to avoid memory corruption * refactor to reuse code, and fix verification * have to give the verify key at the start of the decryption * enfore readAll before signature verification * streaming api for SessionKey * add split message stream apis * name interface params * fix streaming api so it's supported by go-mobile * hide internal writeCloser * fix nil access * added detached sigs methods * started unit testing * unit testing and fixed a bug where key and data packets where inverted * remove unecessary error wrapping * figured out closing order and error handling * add GC calls to mobile writer and reader * remove debugging values and arrays * writer with builtin sha256 * unit testing the mobile helpers * comments and linting * Typo in error Co-authored-by: wussler <aron@wussler.it> * Add GetKeyPacket doc Co-authored-by: wussler <aron@wussler.it> * Add rfc reference in comments Co-authored-by: wussler <aron@wussler.it> * small improvements * add compatibility tests with normal methods * remove unecessary copies in the tests * update go-crypto to the merged changes commit * update comments of core internal functions * remove unused nolint comment * group message metadata in a struct * fix comments * change default values for metadata * change the mobile reader wrapper to fit the behavior of java * remove gc calls in the wrappers to avoid performance penalties * bring back the former Go2MobileReader to be used for ios * Update crypto/keyring_streaming.go Co-authored-by: wussler <aron@wussler.it> * return an error when verifying an embedded sig with no keyring * Update crypto/sessionkey_streaming.go Co-authored-by: wussler <aron@wussler.it> * linter error * update changelog * update changelog Co-authored-by: wussler <aron@wussler.it>
2021-06-30 16:49:30 +02:00 · 2021-06-30 16:49:30 +02:00 · c46ed8ed9e
commit c46ed8ed9e
parent 7380f7391f
11 changed files with 1718 additions and 97 deletions
--- a/crypto/sessionkey_streaming.go
+++ b/crypto/sessionkey_streaming.go
@ -0,0 +1,105 @@
+package crypto
+
+import (
+	"github.com/ProtonMail/go-crypto/openpgp"
+	"github.com/ProtonMail/go-crypto/openpgp/packet"
+	"github.com/pkg/errors"
+)
+
+type signAndEncryptWriteCloser struct {
+	signWriter    WriteCloser
+	encryptWriter WriteCloser
+}
+
+func (w *signAndEncryptWriteCloser) Write(b []byte) (int, error) {
+	return w.signWriter.Write(b)
+}
+
+func (w *signAndEncryptWriteCloser) Close() error {
+	if err := w.signWriter.Close(); err != nil {
+		return err
+	}
+	return w.encryptWriter.Close()
+}
+
+// EncryptStream is used to encrypt data as a Writer.
+// It takes a writer for the encrypted data packet and returns a writer for the plaintext data.
+// If signKeyRing is not nil, it is used to do an embedded signature.
+func (sk *SessionKey) EncryptStream(
+	dataPacketWriter Writer,
+	plainMessageMetadata *PlainMessageMetadata,
+	signKeyRing *KeyRing,
+) (plainMessageWriter WriteCloser, err error) {
+	dc, err := sk.GetCipherFunc()
+	if err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: unable to encrypt with session key")
+	}
+
+	config := &packet.Config{
+		Time:          getTimeGenerator(),
+		DefaultCipher: dc,
+	}
+	var signEntity *openpgp.Entity
+	if signKeyRing != nil {
+		signEntity, err = signKeyRing.getSigningEntity()
+		if err != nil {
+			return nil, errors.Wrap(err, "gopenpgp: unable to sign")
+		}
+	}
+
+	if plainMessageMetadata == nil {
+		// Use sensible default metadata
+		plainMessageMetadata = &PlainMessageMetadata{
+			IsBinary: true,
+			Filename: "",
+			ModTime:  GetUnixTime(),
+		}
+	}
+
+	encryptWriter, signWriter, err := encryptStreamWithSessionKey(
+		plainMessageMetadata.IsBinary,
+		plainMessageMetadata.Filename,
+		uint32(plainMessageMetadata.ModTime),
+		dataPacketWriter,
+		sk,
+		signEntity,
+		config,
+	)
+
+	if err != nil {
+		return nil, err
+	}
+	if signWriter != nil {
+		plainMessageWriter = &signAndEncryptWriteCloser{signWriter, encryptWriter}
+	} else {
+		plainMessageWriter = encryptWriter
+	}
+	return plainMessageWriter, err
+}
+
+// DecryptStream is used to decrypt a data packet as a Reader.
+// It takes a reader for the data packet
+// and returns a PlainMessageReader for the plaintext data.
+// If verifyKeyRing is not nil, PlainMessageReader.VerifySignature() will
+// verify the embedded signature with the given key ring and verification time.
+func (sk *SessionKey) DecryptStream(
+	dataPacketReader Reader,
+	verifyKeyRing *KeyRing,
+	verifyTime int64,
+) (plainMessage *PlainMessageReader, err error) {
+	messageDetails, err := decryptStreamWithSessionKey(
+		sk,
+		dataPacketReader,
+		verifyKeyRing,
+	)
+	if err != nil {
+		return nil, errors.Wrap(err, "gopenpgp: error in reading message")
+	}
+
+	return &PlainMessageReader{
+		messageDetails,
+		verifyKeyRing,
+		verifyTime,
+		false,
+	}, err
+}