Remove juju/errors

obfuscated2/client_protocol.go

@@ -4,11 +4,11 @@ import (
 	"bytes"
 	"crypto/sha256"
 	"encoding/binary"
+	"errors"
+	"fmt"
 	"io"
 	"time"
 
-	"github.com/juju/errors"
-
 	"github.com/9seconds/mtg/antireplay"
 	"github.com/9seconds/mtg/config"
 	"github.com/9seconds/mtg/conntypes"
@@ -26,7 +26,7 @@ type ClientProtocol struct {
 func (c *ClientProtocol) Handshake(socket wrappers.StreamReadWriteCloser) (wrappers.StreamReadWriteCloser, error) {
 	fm, err := c.ReadFrame(socket)
 	if err != nil {
-		return nil, errors.Annotate(err, "Cannot make client handshake")
+		return nil, fmt.Errorf("cannot make a client handshake: %w", err)
 	}
 
 	decHasher := sha256.New()
@@ -76,7 +76,7 @@ func (c *ClientProtocol) Handshake(socket wrappers.StreamReadWriteCloser) (wrapp
 
 func (c *ClientProtocol) ReadFrame(socket wrappers.StreamReader) (fm Frame, err error) {
 	if _, err = io.ReadFull(handshakeReader{socket}, fm.Bytes()); err != nil {
-		err = errors.Annotate(err, "Cannot extract obfuscated2 frame")
+		err = fmt.Errorf("cannot extract obfuscated2 frame: %w", err)
 	}
 	return
 }

obfuscated2/telegram_protocol.go

@@ -2,8 +2,7 @@ package obfuscated2
 
 import (
 	"crypto/rand"
-
-	"github.com/juju/errors"
+	"fmt"
 
 	"github.com/9seconds/mtg/protocol"
 	"github.com/9seconds/mtg/telegram"
@@ -23,7 +22,7 @@ func (t *TelegramProtocol) Handshake(req *protocol.TelegramRequest) (wrappers.Wr
 		req.ClientProtocol.GetDC(),
 		req.ClientProtocol.GetConnectionProtocol())
 	if err != nil {
-		return nil, errors.Annotate(err, "Cannot dial to Telegram")
+		return nil, fmt.Errorf("cannot dial to telegram: %w", err)
 	}
 	fm := generateFrame(req.ClientProtocol)
 	data := fm.Bytes()
@@ -38,7 +37,7 @@ func (t *TelegramProtocol) Handshake(req *protocol.TelegramRequest) (wrappers.Wr
 	copy(data[:frameOffsetIV], copyFrame[:frameOffsetIV])
 
 	if _, err := socket.Write(data); err != nil {
-		return nil, errors.Annotate(err, "Cannot write handshate frame to Telegram")
+		return nil, fmt.Errorf("cannot write handshake frame to telegram: %w", err)
 	}
 
 	return wrappers.NewObfuscated2(socket, encryptor, decryptor), nil