bot contesta con e2ee

shell/matrix/client.go

@@ -3,10 +3,14 @@ package matrix
 
 import (
 	"context"
+	"crypto/sha256"
 	"fmt"
+	"io"
 	"os"
+	"path/filepath"
 
 	"maunium.net/go/mautrix"
+	"maunium.net/go/mautrix/crypto/cryptohelper"
 	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/id"
 
@@ -39,7 +43,44 @@ func New(cfg config.MatrixCfg) (*Client, error) {
 	return &Client{raw: raw, cfg: cfg}, nil
 }
 
+// InitCrypto sets up end-to-end encryption using the mautrix cryptohelper.
+// storePath is the SQLite file path for crypto material (e.g. "./data/crypto/crypto.db").
+// agentID is used to namespace the crypto state so multiple agents can share a database.
+// Returns an io.Closer that must be called on agent shutdown to flush the crypto store.
+func (c *Client) InitCrypto(ctx context.Context, storePath, agentID string) (io.Closer, error) {
+	// Resolve the actual device ID from the server — the value in config may differ
+	// from what the registration process assigned.
+	whoami, err := c.raw.Whoami(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("whoami for crypto init: %w", err)
+	}
+	c.raw.DeviceID = whoami.DeviceID
+
+	// Derive a stable pickle key from the access token.
+	// If the token changes (bot re-registered), delete the crypto store to reset.
+	sum := sha256.Sum256([]byte(c.raw.AccessToken))
+	pickleKey := sum[:]
+
+	if err := os.MkdirAll(filepath.Dir(storePath), 0700); err != nil {
+		return nil, fmt.Errorf("create crypto store dir: %w", err)
+	}
+
+	helper, err := cryptohelper.NewCryptoHelper(c.raw, pickleKey, storePath)
+	if err != nil {
+		return nil, fmt.Errorf("create crypto helper: %w", err)
+	}
+	helper.DBAccountID = agentID
+
+	if err := helper.Init(ctx); err != nil {
+		return nil, fmt.Errorf("init e2ee: %w", err)
+	}
+
+	c.raw.Crypto = helper
+	return helper, nil
+}
+
 // SendText sends a plain-text message to a room.
+// If the room has E2EE enabled and crypto is initialized, the message is encrypted automatically.
 func (c *Client) SendText(ctx context.Context, roomID, text string) error {
 	_, err := c.raw.SendText(ctx, id.RoomID(roomID), text)
 	return err