Add dependencies/vendor (whatsapp)

vendor/go.mau.fi/libsignal/util/keyhelper/KeyHelper.go

@@ -0,0 +1,95 @@
+// Package keyhelper is based on: https://github.com/WhisperSystems/libsignal-protocol-java/blob/master/java/src/main/java/org/whispersystems/libsignal/util/KeyHelper.java
+package keyhelper
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"time"
+
+	"go.mau.fi/libsignal/ecc"
+	"go.mau.fi/libsignal/keys/identity"
+	"go.mau.fi/libsignal/state/record"
+)
+
+// GenerateIdentityKeyPair generates an identity keypair used for
+// signing. Clients should only do this once at install time.
+func GenerateIdentityKeyPair() (*identity.KeyPair, error) {
+	keyPair, err := ecc.GenerateKeyPair()
+	if err != nil {
+		return nil, err
+	}
+
+	publicKey := identity.NewKey(keyPair.PublicKey())
+	return identity.NewKeyPair(publicKey, keyPair.PrivateKey()), nil
+}
+
+// GeneratePreKeys generates a list of PreKeys. Client shsould do this at
+// install time, and subsequently any time the list of PreKeys stored on
+// the server runs low.
+//
+// PreKeys IDs are shorts, so they will eventually be repeated. Clients
+// should store PreKeys in a circular buffer, so that they are repeated
+// as infrequently as possible.
+func GeneratePreKeys(start int, count int, serializer record.PreKeySerializer) ([]*record.PreKey, error) {
+	var preKeys []*record.PreKey
+
+	for i := start; i <= count; i++ {
+		key, err := ecc.GenerateKeyPair()
+		if err != nil {
+			return nil, err
+		}
+		preKeys = append(preKeys, record.NewPreKey(uint32(i), key, serializer))
+	}
+
+	return preKeys, nil
+}
+
+// GenerateLastResortKey will generate the last resort PreKey. Clients should
+// do this only once, at install time, and durably store it for the length
+// of the install.
+func GenerateLastResortKey(serializer record.PreKeySerializer) (*record.PreKey, error) {
+	keyPair, err := ecc.GenerateKeyPair()
+	if err != nil {
+		return nil, err
+	}
+	return record.NewPreKey(0, keyPair, serializer), nil
+}
+
+// GenerateSignedPreKey generates a signed PreKey.
+func GenerateSignedPreKey(identityKeyPair *identity.KeyPair, signedPreKeyID uint32, serializer record.SignedPreKeySerializer) (*record.SignedPreKey, error) {
+	keyPair, err := ecc.GenerateKeyPair()
+	if err != nil {
+		return nil, err
+	}
+	signature := ecc.CalculateSignature(identityKeyPair.PrivateKey(), keyPair.PublicKey().Serialize())
+	timestamp := time.Now().Unix()
+
+	return record.NewSignedPreKey(signedPreKeyID, timestamp, keyPair, signature, serializer), nil
+}
+
+// GenerateRegistrationID generates a registration ID. Clients should only do
+// this once, at install time.
+func GenerateRegistrationID() uint32 {
+	var n uint32
+	binary.Read(rand.Reader, binary.LittleEndian, &n)
+
+	return n
+}
+
+//---------- Group Stuff ----------------
+
+func GenerateSenderSigningKey() (*ecc.ECKeyPair, error) {
+	return ecc.GenerateKeyPair()
+}
+
+func GenerateSenderKey() []byte {
+	randBytes := make([]byte, 32)
+	rand.Read(randBytes)
+	return randBytes
+}
+
+func GenerateSenderKeyID() uint32 {
+	return GenerateRegistrationID()
+}
+
+//---------- End Group Stuff --------------