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Validate reply-path length in repeater anonymous request handlers #3842

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Validate reply-path length in repeater anonymous request handlers #3842

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42 changes: 21 additions & 21 deletions examples/simple_repeater/MyMesh.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -144,14 +144,21 @@ uint8_t MyMesh::handleLoginReq(const mesh::Identity& sender, const uint8_t* secr
return 13; // reply length
}

uint8_t MyMesh::handleAnonRegionsReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data) {
static bool extractReplyPath(const uint8_t* data, size_t len, uint8_t* reply_path, uint8_t& reply_path_len) {
if (len < 1) return false;
uint8_t path_len = *data++;
if (!mesh::Packet::isValidPathLen(path_len)) return false;
size_t path_byte_len = (size_t)(path_len & 63) * ((path_len >> 6) + 1);
if (1 + path_byte_len > len) return false;
reply_path_len = path_len;
mesh::Packet::writePath(reply_path, data, path_len);
return true;
}

uint8_t MyMesh::handleAnonRegionsReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data, size_t len) {
if (anon_limiter.allow(rtc_clock.getCurrentTime())) {
// request data has: {reply-path-len}{reply-path}
reply_path_len = *data++;
if (!mesh::Packet::isValidPathLen(reply_path_len)) return 0; // reject - bad encoding

mesh::Packet::writePath(reply_path, data, reply_path_len);
// data += (uint8_t)reply_path_len * reply_path_hash_size;
if (!extractReplyPath(data, len, reply_path, reply_path_len)) return 0; // reject - bad/incomplete encoding

memcpy(reply_data, &sender_timestamp, 4); // prefix with sender_timestamp, like a tag
uint32_t now = getRTCClock()->getCurrentTime();
Expand All @@ -162,14 +169,10 @@ uint8_t MyMesh::handleAnonRegionsReq(const mesh::Identity& sender, uint32_t send
return 0;
}

uint8_t MyMesh::handleAnonOwnerReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data) {
uint8_t MyMesh::handleAnonOwnerReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data, size_t len) {
if (anon_limiter.allow(rtc_clock.getCurrentTime())) {
// request data has: {reply-path-len}{reply-path}
reply_path_len = *data++;
if (!mesh::Packet::isValidPathLen(reply_path_len)) return 0; // reject - bad encoding

mesh::Packet::writePath(reply_path, data, reply_path_len);
// data += (uint8_t)reply_path_len * reply_path_hash_size;
if (!extractReplyPath(data, len, reply_path, reply_path_len)) return 0; // reject - bad/incomplete encoding

memcpy(reply_data, &sender_timestamp, 4); // prefix with sender_timestamp, like a tag
uint32_t now = getRTCClock()->getCurrentTime();
Expand All @@ -181,14 +184,10 @@ uint8_t MyMesh::handleAnonOwnerReq(const mesh::Identity& sender, uint32_t sender
return 0;
}

uint8_t MyMesh::handleAnonClockReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data) {
uint8_t MyMesh::handleAnonClockReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data, size_t len) {
if (anon_limiter.allow(rtc_clock.getCurrentTime())) {
// request data has: {reply-path-len}{reply-path}
reply_path_len = *data++;
if (!mesh::Packet::isValidPathLen(reply_path_len)) return 0; // reject - bad encoding

mesh::Packet::writePath(reply_path, data, reply_path_len);
// data += (uint8_t)reply_path_len * reply_path_hash_size;
if (!extractReplyPath(data, len, reply_path, reply_path_len)) return 0; // reject - bad/incomplete encoding

memcpy(reply_data, &sender_timestamp, 4); // prefix with sender_timestamp, like a tag
uint32_t now = getRTCClock()->getCurrentTime();
Expand Down Expand Up @@ -572,6 +571,7 @@ void MyMesh::onAnonDataRecv(mesh::Packet *packet, const uint8_t *secret, const m
uint8_t *data, size_t len) {
if (packet->getPayloadType() == PAYLOAD_TYPE_ANON_REQ) { // received an initial request by a possible admin
// client (unknown at this stage)
if (len < 5) return;
uint32_t timestamp;
memcpy(&timestamp, data, 4);

Expand All @@ -582,11 +582,11 @@ void MyMesh::onAnonDataRecv(mesh::Packet *packet, const uint8_t *secret, const m
if (data[4] == 0 || data[4] >= ' ') { // is password, ie. a login request
reply_len = handleLoginReq(sender, secret, timestamp, &data[4], packet->isRouteFlood());
} else if (data[4] == ANON_REQ_TYPE_REGIONS && packet->isRouteDirect()) {
reply_len = handleAnonRegionsReq(sender, timestamp, &data[5]);
reply_len = handleAnonRegionsReq(sender, timestamp, &data[5], len - 5);
} else if (data[4] == ANON_REQ_TYPE_OWNER && packet->isRouteDirect()) {
reply_len = handleAnonOwnerReq(sender, timestamp, &data[5]);
reply_len = handleAnonOwnerReq(sender, timestamp, &data[5], len - 5);
} else if (data[4] == ANON_REQ_TYPE_BASIC && packet->isRouteDirect()) {
reply_len = handleAnonClockReq(sender, timestamp, &data[5]);
reply_len = handleAnonClockReq(sender, timestamp, &data[5], len - 5);
} else {
reply_len = 0; // unknown/invalid request type
}
Expand Down
6 changes: 3 additions & 3 deletions examples/simple_repeater/MyMesh.h
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Original file line number Diff line number Diff line change
Expand Up @@ -118,9 +118,9 @@ class MyMesh : public mesh::Mesh, public CommonCLICallbacks {

void putNeighbour(const mesh::Identity& id, uint32_t timestamp, float snr);
uint8_t handleLoginReq(const mesh::Identity& sender, const uint8_t* secret, uint32_t sender_timestamp, const uint8_t* data, bool is_flood);
uint8_t handleAnonRegionsReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data);
uint8_t handleAnonOwnerReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data);
uint8_t handleAnonClockReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data);
uint8_t handleAnonRegionsReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data, size_t len);
uint8_t handleAnonOwnerReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data, size_t len);
uint8_t handleAnonClockReq(const mesh::Identity& sender, uint32_t sender_timestamp, const uint8_t* data, size_t len);
int handleRequest(ClientInfo* sender, uint32_t sender_timestamp, uint8_t* payload, size_t payload_len);
mesh::Packet* createSelfAdvert();

Expand Down