Fix ECDH livestream for E340 doorbell and T8425 floodlight by lenoxys · Pull Request #779 · bropat/eufy-security-client

lenoxys · 2026-02-09T01:02:04Z

Summary

The BATTERY_DOORBELL_PLUS_E340 (T8214) and the FLOODLIGHT_CAMERA_8425 (T8425) are already recognized by the library but livestream was broken — both devices use ECDH key exchange instead of RSA for P2P session negotiation, and require a different livestream command format than their generic paths.

Changes

ECDH key exchange — When RSA decryption fails during CMD_GATEWAYINFO, the session now falls back to ECDH using the ecc_private_key from the cipher API. If neither succeeds, encryption degrades gracefully to Level 1.
Livestream command routing — The E340 and T8425 require CMD_DOORBELL_SET_PAYLOAD (same as the Outdoor Pan & Tilt Camera) instead of their generic command paths.
Block-alignment guard — Prevents crypto errors when the device sends command responses with an encryption flag but non-block-aligned payload (observed with 36-byte status replies).
Integrated device registration — T8214 and T8425 added to isIntegratedDeviceBySn for correct P2P routing (T8425 was the only floodlight model missing from the list).

Testing

Livestream tested end-to-end on both devices and confirmed working. Unit tests added for decryptP2PKeyECDH.

max246 · 2026-02-09T16:46:31Z

Branch destination should be develop

src/p2p/session.ts

src/p2p/utils.ts

src/http/device.ts

Newer eufy devices (e.g. E340 doorbell) use elliptic-curve cryptography instead of RSA for P2P session key exchange. The cloud cipher API already returns an ecc_private_key field for these devices, but the local Cipher interface did not expose it. Add the optional ecc_private_key property so downstream code can detect whether a device uses ECC and act accordingly.

Some eufy devices negotiate the P2P session key using ECDH (prime256v1) rather than RSA. This adds a dedicated decryption function that handles the three envelope formats observed in the wild: - Raw shared-secret derivation (short key payloads) - Full ECIES envelope (public key + IV + ciphertext + HMAC) - Graceful fallback for unexpected formats The function uses the ECC private key returned by the cipher API to compute the shared secret and derive a 16-byte AES session key.

Devices that use ECC keys send encrypted payloads that RSA cannot decrypt. Instead of failing outright, the session now attempts RSA first and, on failure, transparently falls back to ECDH when an ECC private key is available. If both methods fail, encryption degrades gracefully to Level 1 so the connection is not lost. Additionally, guard AES-ECB decryption against non-block-aligned data. Some command responses (e.g. 36-byte status replies) carry a non-zero signCode but are not actually encrypted. Attempting to decrypt them caused crashes; the guard skips decryption when the payload length is not a multiple of 16 bytes.

The E340 (T8214) is a standalone device where the station serial number matches the device serial number — making it an integrated device. Add it to the serial-number-based detection list so that P2P connection routing and protocol-version decisions handle it correctly, just like other self-contained cameras and doorbells.

The E340 doorbell uses the same livestream command format as the Outdoor Pan & Tilt Camera (CMD_DOORBELL_SET_PAYLOAD) — a JSON payload containing accountId, encryptkey, streamtype, and related fields. Without this, the generic branch would send CMD_START_REALTIME_MEDIA which the E340 does not understand. Route the E340 through the existing Outdoor PT Camera livestream path rather than duplicating the logic, since the payload format is identical.

lenoxys · 2026-02-09T17:42:34Z

Branch destination should be develop

done

… subarray call

lenoxys · 2026-02-09T18:31:50Z

@max246 done, let's me know !

Same ECDH+livestream pattern as the E340 doorbell: the T8425 uses ECDH key exchange and needs the CMD_DOORBELL_SET_PAYLOAD path to produce video data. Also adds T8425 to isIntegratedDeviceBySn (was the only floodlight model missing from the list).

lenoxys · 2026-02-11T22:54:41Z

@max246, I discovered that the T8425 floodlight has the exact same issue — ECDH key exchange instead of RSA, and needs the CMD_DOORBELL_SET_PAYLOAD path. I've added support for it in the latest commit and updated the PR description accordingly. Tested on both devices.

…pport Track lenoxys/eufy-security-client on branch feat/e340-doorbell-support which includes ECDH livestream fixes for E340 doorbell and T8425 floodlight (upstream PR bropat/eufy-security-client#779).

…pport - Add lenoxys/eufy-security-client (feat/e340-doorbell-support branch) as git submodule - Switch dependency from npm registry to local file: reference - Add build-lib script to build chain for submodule compilation - Temporary measure pending upstream merge of bropat/eufy-security-client#779

max246 · 2026-02-13T23:09:24Z

Thank you! Approved it, you can merge it

lenoxys · 2026-02-14T15:44:50Z

Thank you! Approved it, you can merge it

Not sure what to do, I'm not a collaborator

max246 · 2026-02-14T17:14:16Z

ok need to press merge , just missed the cut release :(

lenoxys · 2026-02-14T17:19:16Z

Any chance to have 3.7.1 ?

max246 · 2026-02-14T18:02:54Z

sure we can do one during tomorrow if I manage :D just a bit.. complicate to release the 3 packages.

lenoxys · 2026-02-14T18:08:33Z

Up to you ! No pressure !

Add T85V0 to isLockWifiVideo (gateway handshake), isIntegratedDeviceBySn (P2P routing), and CMD_DOORBELL_SET_PAYLOAD (1) livestream path (same as E340/T8425). ECDH fallback from PR bropat#779 handles key exchange; no WebRTC-only override needed in v3.7.1. Co-authored-by: Cursor <[email protected]>

Add T85V0 (Smart Lock S3 Max) basic streaming capability: - Add LOCK_85V0 device type (203) and core device properties - Add isLockWifiT85V0() static and instance methods - Enable ECDH encryption via isLockWifiVideo() - Enable P2P routing via isIntegratedDeviceBySn() - Route to CMD_DOORBELL_SET_PAYLOAD (1) for streaming - Add StreamLivestream/StopLivestream commands Based on latest upstream master (c1432e5) with restored T8425/E340 streaming routing from reverted PR bropat#779. Tested: Both T85V0 and T8425 streaming confirmed working. Co-authored-by: Cursor <[email protected]>

- Add DeviceUnlock command for T85V0 (removed non-existent DeviceLock) - Fix 'data not block-aligned' decryption errors in P2P session - Add block-alignment guards before AES-128-ECB decryption - Skip decryption with debug log for non-aligned data - Fixes lock commands that were failing due to upstream revert of PR bropat#779 Addresses the 'Skipping decryption, data not block-aligned' errors seen in Home Assistant logs for T85V0 lock operations. Co-authored-by: Cursor <[email protected]>

…ream PR bropat#790 Upstream reverted PR bropat#779 in commit c61c4a1, removing decryptP2PKeyECDH, the RSA-to-ECDH fallback chain, the block-alignment guard, and the ecc_private_key model field. This restores all of those plus the exact byte extraction fix for readNullTerminatedBuffer issues. Co-authored-by: Cursor <[email protected]>

lenoxys mentioned this pull request Feb 9, 2026

Eufy E340 Dual Cam Doorbell live stream problem homebridge-plugins/homebridge-eufy-security#741

Closed

3 tasks

max246 requested changes Feb 9, 2026

View reviewed changes

src/p2p/session.ts Outdated Show resolved Hide resolved

src/p2p/session.ts Outdated Show resolved Hide resolved

src/p2p/session.ts Outdated Show resolved Hide resolved

src/p2p/utils.ts Show resolved Hide resolved

max246 requested changes Feb 9, 2026

View reviewed changes

src/http/device.ts Outdated Show resolved Hide resolved

lenoxys added 5 commits February 9, 2026 13:38

lenoxys force-pushed the feat/e340-doorbell-support branch from 5282904 to 0dd59e9 Compare February 9, 2026 17:40

lenoxys changed the base branch from master to develop February 9, 2026 17:40

lenoxys added 3 commits February 9, 2026 13:47

refactor: derive encryptedKey from rawEncryptedKey to avoid duplicate…

dddfc86

… subarray call

refactor: simplify signed data decryption condition

5016ce9

test: add unit tests for decryptP2PKeyECDH fucntion

939ef11

lenoxys changed the title ~~Feat/e340 doorbell support~~ Fix E340 doorbell (T8214) livestream Feb 11, 2026

lenoxys changed the title ~~Fix E340 doorbell (T8214) livestream~~ Fix ECDH livestream for E340 doorbell and T8425 floodlight Feb 11, 2026

lenoxys mentioned this pull request Feb 11, 2026

[Bug]: Old floodlight cam works, but E340 floodlight does not work (without HomeBase3) homebridge-plugins/homebridge-eufy-security#699

Closed

lenoxys mentioned this pull request Feb 12, 2026

feat: use patched eufy-security-client for E340 doorbell & T8425 floodlight livestream homebridge-plugins/homebridge-eufy-security#761

Merged

lenoxys mentioned this pull request Feb 12, 2026

feat: add eufy-security-client fork as submodule for E340 doorbell support homebridge-plugins/homebridge-eufy-security#767

Merged

max246 approved these changes Feb 13, 2026

View reviewed changes

max246 merged commit b0f3b33 into bropat:develop Feb 14, 2026
2 checks passed

lenoxys deleted the feat/e340-doorbell-support branch February 14, 2026 22:43

max246 mentioned this pull request Feb 15, 2026

Release/3.7.1 #787

Merged

max246 mentioned this pull request Feb 16, 2026

Revert "Fix ECDH livestream for E340 doorbell and T8425 floodlight" #790

Merged

lenoxys mentioned this pull request Feb 16, 2026

Fix T8214 and T8425 livestream #793

Merged

This was referenced Mar 6, 2026

fix: E340 talkback — streamType, seq counters, command routing #836

Closed

fix: E340 talkback — streamType, seq counters, command routing #837

Open

PatrickSobau-gk mentioned this pull request Mar 24, 2026

[Bug]: No video on Doorbell E340. iobroker-community-adapters/ioBroker.eusec#39

Open

Uh oh!

Conversation

lenoxys commented Feb 9, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Changes

Testing

Uh oh!

max246 commented Feb 9, 2026

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

lenoxys commented Feb 9, 2026

Uh oh!

lenoxys commented Feb 9, 2026

Uh oh!

lenoxys commented Feb 11, 2026

Uh oh!

max246 commented Feb 13, 2026

Uh oh!

lenoxys commented Feb 14, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

max246 commented Feb 14, 2026

Uh oh!

Uh oh!

lenoxys commented Feb 14, 2026

Uh oh!

max246 commented Feb 14, 2026

Uh oh!

lenoxys commented Feb 14, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

lenoxys commented Feb 9, 2026 •

edited

Loading

lenoxys commented Feb 14, 2026 •

edited

Loading