Packet Signing via XEdDSA by jp-bennett · Pull Request #10478 · meshtastic/firmware

jp-bennett · 2026-05-14T19:03:18Z

New PR after a particularly ugly merge.

* Generate a new node identity on key generation * Fixes * Fixes * Fixes * Messed up * Fixes * Update src/modules/AdminModule.cpp Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update src/mesh/NodeDB.cpp Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Figured it out! * Cleanup * Update src/mesh/NodeDB.h Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update src/mesh/NodeDB.cpp Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update src/modules/AdminModule.cpp Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* fix: add null check for getMeshNode() in NodeInfoModule getMeshNode() can return nullptr for unknown nodes. Dereferencing without a check crashes the firmware when receiving NodeInfo from a node not yet in the database. * fix: enforce XEdDSA signature verification and prevent stripping Previously, failed signature verification still allowed the packet through, making signatures purely cosmetic. Now: - Failed verification drops the packet (DECODE_FAILURE) - Successfully verified nodes get HAS_XEDDSA_SIGNED bitfield set - Unsigned packets from previously-signing nodes are rejected - Log levels reduced from WARN/ERROR to DEBUG/WARN as appropriate * fix: include packet metadata in XEdDSA signature The signature now covers [fromNode | packetId | portnum | payload] instead of just the payload bytes. This prevents: - Replay attacks (different packetId fails verification) - Reattribution (different fromNode fails verification) - Portnum redirection (different portnum fails verification) Also adds a key initialization check to xeddsa_sign (returns false if XEdDSA keys are all zeros) and checks the return value in the encode path. * fix: handle existing key pair in AdminModule security config When a user provides both a valid private key and public key via admin config, the crypto engine's DH private key and owner public key were never loaded. DMs and XEdDSA signing would silently break. Add an else branch to load both keys into the crypto engine. * perf: cache Ed25519 public key conversion in xeddsa_verify curve_to_ed_pub() performs field element parsing, inversion, and multiplication on every call. Since packets from the same node tend to arrive in bursts, a single-entry cache avoids repeating this expensive conversion for consecutive packets from one sender. * fix: skip identity cleanup when node number is unchanged createNewIdentity() was called on every generateCryptoKeyPair(), including normal boots where the same key is regenerated. This caused unnecessary NodeDB writes and old-node cleanup logic to run when the node number hadn't actually changed. Also fixes only zeroing byte[0] of the old node's public key instead of clearing the entire array. * fix: replace hardcoded 120 with derived XEDDSA_SIGNATURE_SIZE constant The payload size check for XEdDSA signing used a magic number (120). Replace with a derivation from DATA_PAYLOAD_LEN and XEDDSA_SIGNATURE_SIZE so the limit adjusts automatically if constants change. This also increases the max signable payload from 120 to 169 bytes, which is still safe since the actual encoded size is checked after pb_encode. * fix: add const qualifiers to XEdDSA verify and curve_to_ed_pub inputs pubKey, payload, and signature parameters in xeddsa_verify are input-only and should not be modified. Same for curve_pubkey in curve_to_ed_pub. * chore: remove commented-out old Crypto dependency in portduino.ini * Leave out the admin module change for now --------- Co-authored-by: Jonathan Bennett <jbennett@incomsystems.biz>

Copilot

Pull request overview

This PR introduces XEdDSA-based packet signing support across the firmware (signing on transmit, verification on receive, and persistence of “signer” state per node), adds unit tests for the signing primitives, and switches multiple PlatformIO environments to a Meshtastic-hosted Crypto library fork to pick up the required crypto APIs.

Changes:

Switch platform lib_deps from rweather/Crypto (and STM32’s previous Crypto source) to a pinned meshtastic/Crypto GitHub zip across several variants.
Add XEdDSA sign/verify support in CryptoEngine and integrate signature verify + “previously signed” enforcement in Router.
Consolidate PKI key generation in NodeDB and add XEdDSA unit tests.

Reviewed changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 15 comments.

Show a summary per file

File	Description
variants/stm32/stm32.ini	Switch STM32 Crypto dependency to Meshtastic fork (pinned zip).
variants/rp2350/rp2350.ini	Switch RP2350 Crypto dependency to Meshtastic fork (pinned zip).
variants/rp2040/rp2040.ini	Switch RP2040 Crypto dependency to Meshtastic fork (pinned zip).
variants/nrf52840/nrf52.ini	Switch nRF52 Crypto dependency to Meshtastic fork (pinned zip).
variants/native/portduino.ini	Switch Portduino Crypto dependency to Meshtastic fork (pinned zip).
variants/esp32c6/esp32c6.ini	Switch ESP32-C6 Crypto dependency to Meshtastic fork (pinned zip).
variants/esp32/esp32-common.ini	Switch ESP32 common Crypto dependency to Meshtastic fork (pinned zip).
test/test_crypto/test_main.cpp	Add XEdDSA sign/verify unit tests.
src/modules/NodeInfoModule.cpp	Reject unsigned NodeInfo from nodes previously observed signing.
src/modules/AdminModule.cpp	Rework security config handling to use NodeDB keypair generation + force reboot/save segments.
src/mesh/TypeConversions.cpp	Expose per-node “has_xeddsa_signed” status in NodeInfo conversion.
src/mesh/Router.cpp	Verify signatures on decode; sign outgoing broadcasts when size allows; enforce “previously signed” policy.
src/mesh/NodeDB.h	Add NodeDB crypto keypair helper + new bitfield flag/accessor for XEdDSA signing.
src/mesh/NodeDB.cpp	Implement consolidated crypto key generation and identity switching logic.
src/mesh/CryptoEngine.h	Add XEdDSA signing API + cache fields and Curve25519→Ed25519 pubkey conversion hook.
src/mesh/CryptoEngine.cpp	Implement XEdDSA signing/verification and Curve25519→Ed25519 pubkey conversion.

+            // Unsigned packet — reject if this node previously sent signed packets
+            meshtastic_NodeInfoLite *node = nodeDB->getMeshNode(p->from);
+            if (node && nodeInfoLiteHasXeddsaSigned(node)) {
+                LOG_WARN("Dropping unsigned packet from 0x%08x that previously signed", p->from);
+                return DecodeState::DECODE_FAILURE;


+    }
+
+    bool keygenSuccess = false;
+    bool lowEntropy = checkLowEntropyPublicKey(config.security.public_key);


+    // Retire the old node entry
+    meshtastic_NodeInfoLite *node = getMeshNode(oldNodeNum);
+    if (node != NULL) {
+        LOG_DEBUG("Old node num %u is now %u", oldNodeNum, newNodeNum);
+        nodeInfoLiteSetBit(node, NODEINFO_BITFIELD_IS_IGNORED_MASK, true);


+    // format of Ed25519 public keys only in a single sign bit. This function assumes that the sign bit is
+    // known to the user and is passed accordingly.


Xaositek · 2026-05-15T01:09:51Z

Should #7602 be closed in favor of this?

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

thebentern · 2026-05-19T12:04:53Z

@copilot resolve the merge conflicts in this pull request

Co-authored-by: thebentern <9000580+thebentern@users.noreply.github.com>

Copilot · 2026-05-19T12:16:27Z

@copilot resolve the merge conflicts in this pull request

Resolved the merge conflict and pushed the merge commit in 80727e8.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

api.registry.nm1.platformio.org
- Triggering command: /home/REDACTED/.local/bin/pio /home/REDACTED/.local/bin/pio test -e native -f test_crypto (dns block)
- Triggering command: /home/REDACTED/.local/bin/pio /home/REDACTED/.local/bin/pio test -e native -f test_crypto -v ndor/bin/git (dns block)
api.registry.platformio.org
- Triggering command: /home/REDACTED/.local/bin/pio /home/REDACTED/.local/bin/pio test -e native -f test_crypto (dns block)
- Triggering command: /home/REDACTED/.local/bin/pio /home/REDACTED/.local/bin/pio test -e native -f test_crypto -v ndor/bin/git (dns block)
collector.platformio.org
- Triggering command: /home/REDACTED/.local/bin/pio /home/REDACTED/.local/bin/pio test -e native -f test_crypto (dns block)
- Triggering command: /home/REDACTED/.local/bin/pio /home/REDACTED/.local/bin/pio project config --environment tlora_c6 --json-output (dns block)
- Triggering command: /home/REDACTED/.local/bin/pio /home/REDACTED/.local/bin/pio project config -h (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

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jp-bennett and others added 12 commits May 13, 2026 12:02

Test commit for XEdDSA support

08c2a61

Update to Crypto lib in Meshtatic org

171a8a9

Update crypto commit hash

2c7a1d5

trunk

6b1381c

protobuf re-update

aa9d86d

Protobufs

d8844ce

Merge resolution fix

aa9ffe2

Put XEDDSA on the right bit

546db5f

NodeDB update to new nodeInfoLite accessors, etc

599ec99

Merge branch 'develop' into XEdDSA-merge

064c006

github-actions Bot added needs-review Needs human review enhancement New feature or request labels May 14, 2026

thebentern requested a review from Copilot May 14, 2026 19:32

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thebentern and others added 11 commits May 15, 2026 16:01

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Merge branch 'develop' into XEdDSA-merge

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Copilot started work on behalf of thebentern May 19, 2026 12:05 View session

Merge develop into XEdDSA-merge

80727e8

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Copilot AI requested a review from thebentern May 19, 2026 12:17

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thebentern added 2 commits May 21, 2026 06:02

Merge branch 'develop' into XEdDSA-merge

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Merge branch 'develop' into XEdDSA-merge

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Packet Signing via XEdDSA#10478

Packet Signing via XEdDSA#10478
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		// format of Ed25519 public keys only in a single sign bit. This function assumes that the sign bit is
		// known to the user and is passed accordingly.

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