Add manual decrypt utility

libgm/manualdecrypt/main.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"os/exec"
+
+	"google.golang.org/protobuf/proto"
+
+	"go.mau.fi/mautrix-gmessages/libgm/crypto"
+	"go.mau.fi/mautrix-gmessages/libgm/gmproto"
+	"go.mau.fi/mautrix-gmessages/libgm/pblite"
+)
+
+func must[T any](t T, err error) T {
+	if err != nil {
+		panic(err)
+	}
+	return t
+}
+
+func mustNoReturn(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+var requestType = map[gmproto.ActionType]proto.Message{
+	gmproto.ActionType_LIST_CONVERSATIONS:         &gmproto.ListConversationsRequest{},
+	gmproto.ActionType_NOTIFY_DITTO_ACTIVITY:      &gmproto.NotifyDittoActivityRequest{},
+	gmproto.ActionType_GET_CONVERSATION_TYPE:      &gmproto.GetConversationTypeRequest{},
+	gmproto.ActionType_GET_CONVERSATION:           &gmproto.GetConversationRequest{},
+	gmproto.ActionType_LIST_MESSAGES:              &gmproto.ListMessagesRequest{},
+	gmproto.ActionType_SEND_MESSAGE:               &gmproto.SendMessageRequest{},
+	gmproto.ActionType_SEND_REACTION:              &gmproto.SendReactionRequest{},
+	gmproto.ActionType_DELETE_MESSAGE:             &gmproto.DeleteMessageRequest{},
+	gmproto.ActionType_GET_PARTICIPANTS_THUMBNAIL: &gmproto.GetParticipantThumbnailRequest{},
+	gmproto.ActionType_LIST_CONTACTS:              &gmproto.ListContactsRequest{},
+	gmproto.ActionType_LIST_TOP_CONTACTS:          &gmproto.ListTopContactsRequest{},
+	gmproto.ActionType_GET_OR_CREATE_CONVERSATION: &gmproto.GetOrCreateConversationRequest{},
+	gmproto.ActionType_UPDATE_CONVERSATION:        &gmproto.UpdateConversationRequest{},
+}
+
+func main() {
+	var x crypto.AESCTRHelper
+	file, err := os.Open("config.json")
+	if errors.Is(err, os.ErrNotExist) {
+		_ = file.Close()
+		_, _ = fmt.Fprintln(os.Stderr, "config.json doesn't exist")
+		_, _ = fmt.Fprintln(os.Stderr, "Please find pr_crypto_msg_enc_key and pr_crypto_msg_hmac from localStorage")
+		_, _ = fmt.Fprintln(os.Stderr, "(make sure not to confuse it with pr_crypto_hmac)")
+		stdin := bufio.NewScanner(os.Stdin)
+		_, _ = fmt.Fprint(os.Stderr, "AES key (pr_crypto_msg_enc_key): ")
+		stdin.Scan()
+		x.AESKey = must(base64.StdEncoding.DecodeString(stdin.Text()))
+		if len(x.AESKey) != 32 {
+			_, _ = fmt.Fprintln(os.Stderr, "AES key must be 32 bytes")
+			return
+		}
+		_, _ = fmt.Fprint(os.Stderr, "HMAC key (pr_crypto_msg_hmac): ")
+		stdin.Scan()
+		x.HMACKey = must(base64.StdEncoding.DecodeString(stdin.Text()))
+		if len(x.HMACKey) != 32 {
+			_, _ = fmt.Fprintln(os.Stderr, "HMAC key must be 32 bytes")
+			return
+		}
+		file, err = os.OpenFile("config.json", os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0600)
+		if err != nil {
+			_, _ = fmt.Fprintln(os.Stderr, "Failed to open config.json for writing")
+			return
+		}
+		mustNoReturn(json.NewEncoder(file).Encode(&x))
+		_, _ = fmt.Fprintln(os.Stderr, "Saved keys to config.json")
+	} else {
+		mustNoReturn(json.NewDecoder(file).Decode(&x))
+	}
+	_ = file.Close()
+	_, _ = fmt.Fprintln(os.Stderr, "Please paste the request body, then press Ctrl+D to close stdin")
+	d := must(io.ReadAll(os.Stdin))
+	var decoded []byte
+	var typ gmproto.MessageType
+	if json.Valid(d) {
+		var orm gmproto.OutgoingRPCMessage
+		mustNoReturn(pblite.Unmarshal(d, &orm))
+		decoded = orm.Data.MessageData
+		typ = orm.Data.MessageTypeData.MessageType
+	} else {
+		decoded = must(base64.StdEncoding.DecodeString(string(d)))
+	}
+	outgoing := true
+	if outgoing {
+		var ord gmproto.OutgoingRPCData
+		mustNoReturn(proto.Unmarshal(decoded, &ord))
+		_, _ = fmt.Fprintln(os.Stderr)
+		_, _ = fmt.Fprintln(os.Stderr, "CHANNEL:", typ.String())
+		_, _ = fmt.Fprintln(os.Stderr, "REQUEST TYPE:", ord.Action.String())
+		_, _ = fmt.Fprintln(os.Stderr, "REQUEST ID:", ord.RequestID)
+		if ord.EncryptedProtoData == nil {
+			_, _ = fmt.Fprintln(os.Stderr, "No encrypted data")
+			return
+		}
+		decrypted := must(x.Decrypt(ord.EncryptedProtoData))
+		_, _ = fmt.Fprintln(os.Stderr, "------------------------------ RAW DECRYPTED DATA ------------------------------")
+		fmt.Println(base64.StdEncoding.EncodeToString(decrypted))
+		_, _ = fmt.Fprintln(os.Stderr, "--------------------------------- DECODED DATA ---------------------------------")
+		cmd := exec.Command("protoc", "--decode_raw")
+		cmd.Stdin = bytes.NewReader(decrypted)
+		cmd.Stdout = os.Stderr
+		cmd.Stderr = os.Stderr
+		mustNoReturn(cmd.Run())
+		respType, ok := requestType[ord.Action]
+		if ok {
+			respData := respType.ProtoReflect().New().Interface()
+			mustNoReturn(proto.Unmarshal(decrypted, respData))
+			_, _ = fmt.Fprintln(os.Stderr, "------------------------------ PARSED STRUCT DATA ------------------------------")
+			_, _ = fmt.Fprintf(os.Stderr, "%+v\n", respData)
+		}
+	} else {
+		var ird gmproto.RPCMessageData
+		mustNoReturn(proto.Unmarshal(decoded, &ird))
+		decrypted := must(x.Decrypt(ird.EncryptedData))
+		_, _ = fmt.Fprintln(os.Stderr)
+		_, _ = fmt.Fprintln(os.Stderr, "CHANNEL:", typ.String())
+		_, _ = fmt.Fprintln(os.Stderr, "REQUEST TYPE:", ird.Action.String())
+		_, _ = fmt.Fprintln(os.Stderr, "REQUEST ID:", ird.SessionID)
+		_, _ = fmt.Fprintln(os.Stderr, "------------------------------ RAW DECRYPTED DATA ------------------------------")
+		fmt.Println(base64.StdEncoding.EncodeToString(decrypted))
+	}
+	_, _ = fmt.Fprintln(os.Stderr, "--------------------------------------------------------------------------------")
+}