119 lines
3.9 KiB
Go
119 lines
3.9 KiB
Go
// Copyright (c) 2020 Tulir Asokan
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//
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// This Source Code Form is subject to the terms of the Mozilla Public
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// License, v. 2.0. If a copy of the MPL was not distributed with this
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// file, You can obtain one at http://mozilla.org/MPL/2.0/.
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package crypto
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import (
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"encoding/json"
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"fmt"
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"maunium.net/go/mautrix"
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"maunium.net/go/mautrix/crypto/olm"
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"maunium.net/go/mautrix/event"
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"maunium.net/go/mautrix/id"
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)
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func (mach *OlmMachine) encryptOlmEvent(session *OlmSession, recipient *DeviceIdentity, evtType event.Type, content event.Content) *event.EncryptedEventContent {
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evt := &DecryptedOlmEvent{
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Sender: mach.Client.UserID,
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SenderDevice: mach.Client.DeviceID,
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Keys: OlmEventKeys{Ed25519: mach.account.SigningKey()},
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Recipient: recipient.UserID,
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RecipientKeys: OlmEventKeys{Ed25519: recipient.SigningKey},
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Type: evtType,
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Content: content,
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}
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plaintext, err := json.Marshal(evt)
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if err != nil {
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panic(err)
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}
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mach.Log.Trace("Encrypting olm message for %s with session %s: %s", recipient.IdentityKey, session.ID(), session.Describe())
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msgType, ciphertext := session.Encrypt(plaintext)
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err = mach.CryptoStore.UpdateSession(recipient.IdentityKey, session)
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if err != nil {
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mach.Log.Warn("Failed to update olm session in crypto store after encrypting: %v", err)
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}
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return &event.EncryptedEventContent{
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Algorithm: id.AlgorithmOlmV1,
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SenderKey: mach.account.IdentityKey(),
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OlmCiphertext: event.OlmCiphertexts{
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recipient.IdentityKey: {
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Type: msgType,
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Body: string(ciphertext),
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},
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},
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}
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}
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func (mach *OlmMachine) shouldCreateNewSession(identityKey id.IdentityKey) bool {
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if !mach.CryptoStore.HasSession(identityKey) {
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return true
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}
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mach.devicesToUnwedgeLock.Lock()
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_, shouldUnwedge := mach.devicesToUnwedge[identityKey]
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if shouldUnwedge {
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delete(mach.devicesToUnwedge, identityKey)
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}
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mach.devicesToUnwedgeLock.Unlock()
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return shouldUnwedge
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}
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func (mach *OlmMachine) createOutboundSessions(input map[id.UserID]map[id.DeviceID]*DeviceIdentity) error {
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request := make(mautrix.OneTimeKeysRequest)
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for userID, devices := range input {
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request[userID] = make(map[id.DeviceID]id.KeyAlgorithm)
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for deviceID, identity := range devices {
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if mach.shouldCreateNewSession(identity.IdentityKey) {
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request[userID][deviceID] = id.KeyAlgorithmSignedCurve25519
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}
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}
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if len(request[userID]) == 0 {
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delete(request, userID)
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}
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}
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if len(request) == 0 {
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return nil
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}
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resp, err := mach.Client.ClaimKeys(&mautrix.ReqClaimKeys{
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OneTimeKeys: request,
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Timeout: 10 * 1000,
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})
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if err != nil {
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return fmt.Errorf("failed to claim keys: %w", err)
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}
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for userID, user := range resp.OneTimeKeys {
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for deviceID, oneTimeKeys := range user {
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var oneTimeKey mautrix.OneTimeKey
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var keyID id.KeyID
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for keyID, oneTimeKey = range oneTimeKeys {
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break
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}
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keyAlg, keyIndex := keyID.Parse()
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if keyAlg != id.KeyAlgorithmSignedCurve25519 {
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mach.Log.Warn("Unexpected key ID algorithm in one-time key response for %s of %s: %s", deviceID, userID, keyID)
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continue
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}
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identity := input[userID][deviceID]
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if ok, err := olm.VerifySignatureJSON(oneTimeKey, userID, deviceID.String(), identity.SigningKey); err != nil {
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mach.Log.Error("Failed to verify signature for %s of %s: %v", deviceID, userID, err)
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} else if !ok {
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mach.Log.Warn("Invalid signature for %s of %s", deviceID, userID)
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} else if sess, err := mach.account.Internal.NewOutboundSession(identity.IdentityKey, oneTimeKey.Key); err != nil {
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mach.Log.Error("Failed to create outbound session for %s of %s: %v", deviceID, userID, err)
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} else {
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wrapped := wrapSession(sess)
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err = mach.CryptoStore.AddSession(identity.IdentityKey, wrapped)
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if err != nil {
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mach.Log.Error("Failed to store created session for %s of %s: %v", deviceID, userID, err)
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} else {
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mach.Log.Debug("Created new Olm session with %s/%s (OTK ID: %d)", userID, deviceID, keyIndex)
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}
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}
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}
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}
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return nil
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}
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