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Rewrite security personalization data validation (#885)

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* Data is not validated on Linux systems
* If encryption is enabled, data is also validated even if signing
  is disabled.
This commit is contained in:
Patrick Fallberg
2017-07-04 15:49:57 +02:00
committed by Thomas Mørch
parent ff0953dd05
commit 4ea0c88ac8
4 changed files with 99 additions and 63 deletions
Download Patch File Download Diff File Expand all files Collapse all files
MySensors.h
+5 -2
View File
@@ -1,4 +1,4 @@
/*
/*
* The MySensors Arduino library handles the wireless radio link and protocol
* between your home built sensors/actuators and HA controller of choice.
* The sensors forms a self healing radio network with optional repeaters. Each
@@ -145,7 +145,10 @@ MY_DEFAULT_RX_LED_PIN in your sketch instead to enable LEDs
// SIGNING
#if defined(MY_SIGNING_ATSHA204) || defined(MY_SIGNING_SOFT)
#define MY_SIGNING_FEATURE //!< MY_SIGNING_FEATURE
#define MY_SIGNING_FEATURE //!< MY_SIGNING_FEATURE
#endif
#if defined(MY_RF24_ENABLE_ENCRYPTION) || defined(MY_RFM69_ENABLE_ENCRYPTION) || defined(MY_NRF5_ESB_ENABLE_ENCRYPTION)
#define MY_ENCRYPTION_FEATURE //!< MY_ENCRYPTION_FEATURE
#endif
#include "core/MySigning.cpp"
#include "drivers/ATSHA204/sha256.cpp"
core/MySigning.cpp
+92 -34
View File
@@ -38,10 +38,11 @@
#error You have to pick one and only one signing backend
#endif
#ifdef MY_SIGNING_FEATURE
uint8_t _doSign[32]; // Bitfield indicating which sensors require signed communication
uint8_t _doWhitelist[32]; // Bitfield indicating which sensors require serial salted signatures
MyMessage _msgSign; // Buffer for message to sign.
uint8_t _signingNonceStatus;
static uint8_t _doSign[32]; // Bitfield indicating which sensors require signed communication
static uint8_t _doWhitelist[32]; // Bitfield indicating which sensors require salted signatures
static MyMessage _msgSign; // Buffer for message to sign.
static uint8_t _signingNonceStatus;
static bool stateValid = false;
#ifdef MY_NODE_LOCK_FEATURE
static uint8_t nof_nonce_requests = 0;
@@ -98,9 +99,25 @@ static void prepareSigningPresentation(MyMessage &msg, uint8_t destination);
static bool signerInternalProcessPresentation(MyMessage &msg);
static bool signerInternalProcessNonceRequest(MyMessage &msg);
static bool signerInternalProcessNonceResponse(MyMessage &msg);
#if defined(MY_ENCRYPTION_FEATURE) || defined(MY_SIGNING_FEATURE)
static bool signerInternalValidatePersonalization(void);
#endif
void signerInit(void)
{
#if defined(MY_SIGNING_FEATURE)
stateValid = true;
#endif
#if defined (MY_ENCRYPTION_FEATURE) || defined (MY_SIGNING_FEATURE)
if (!signerInternalValidatePersonalization()) {
SIGN_DEBUG(PSTR("!SGN:PER:TAMPERED\n"));
#if defined(MY_SIGNING_FEATURE)
stateValid = false;
#endif
} else {
SIGN_DEBUG(PSTR("SGN:PER:OK\n"));
}
#endif
#if defined(MY_SIGNING_FEATURE)
// Read out the signing requirements from EEPROM
hwReadConfigBlock((void*)_doSign, (void*)EEPROM_SIGNING_REQUIREMENT_TABLE_ADDRESS,
@@ -182,38 +199,44 @@ bool signerSignMsg(MyMessage &msg)
if (skipSign(msg)) {
ret = true;
} else {
// Send nonce-request
_signingNonceStatus=SIGN_WAITING_FOR_NONCE;
if (!_sendRoute(build(_msgSign, msg.destination, msg.sensor, C_INTERNAL,
I_NONCE_REQUEST).set(""))) {
SIGN_DEBUG(PSTR("!SGN:SGN:NCE REQ,TO=%d FAIL\n"),
msg.destination); // Failed to transmit nonce request!
// Before starting, validate that our state is good, or signing will fail
if (!stateValid) {
SIGN_DEBUG(PSTR("!SGN:SGN:STATE\n")); // Signing system is not in a valid state
ret = false;
} else {
SIGN_DEBUG(PSTR("SGN:SGN:NCE REQ,TO=%d\n"), msg.destination); // Nonce requested
// We have to wait for the nonce to arrive before we can sign our original message
// Other messages could come in-between. We trust _process() takes care of them
unsigned long enter = hwMillis();
_msgSign = msg; // Copy the message to sign since buffer might be touched in _process()
while (hwMillis() - enter < MY_VERIFICATION_TIMEOUT_MS &&
_signingNonceStatus==SIGN_WAITING_FOR_NONCE) {
_process();
}
if (hwMillis() - enter > MY_VERIFICATION_TIMEOUT_MS) {
SIGN_DEBUG(PSTR("!SGN:SGN:NCE TMO\n")); // Timeout waiting for nonce!
// Send nonce-request
_signingNonceStatus=SIGN_WAITING_FOR_NONCE;
if (!_sendRoute(build(_msgSign, msg.destination, msg.sensor, C_INTERNAL,
I_NONCE_REQUEST).set(""))) {
SIGN_DEBUG(PSTR("!SGN:SGN:NCE REQ,TO=%d FAIL\n"),
msg.destination); // Failed to transmit nonce request!
ret = false;
} else {
if (_signingNonceStatus == SIGN_OK) {
// process() received a nonce and signerProcessInternal successfully signed the message
msg = _msgSign; // Write the signed message back
SIGN_DEBUG(PSTR("SGN:SGN:SGN\n")); // Message to send has been signed
ret = true;
// After this point, only the 'last' member of the message structure is allowed to be
// altered if the message has been signed, or signature will become invalid and the
// message rejected by the receiver
} else {
SIGN_DEBUG(PSTR("!SGN:SGN:SGN FAIL\n")); // Message to send could not be signed!
SIGN_DEBUG(PSTR("SGN:SGN:NCE REQ,TO=%d\n"), msg.destination); // Nonce requested
// We have to wait for the nonce to arrive before we can sign our original message
// Other messages could come in-between. We trust _process() takes care of them
unsigned long enter = hwMillis();
_msgSign = msg; // Copy the message to sign since buffer might be touched in _process()
while (hwMillis() - enter < MY_VERIFICATION_TIMEOUT_MS &&
_signingNonceStatus==SIGN_WAITING_FOR_NONCE) {
_process();
}
if (hwMillis() - enter > MY_VERIFICATION_TIMEOUT_MS) {
SIGN_DEBUG(PSTR("!SGN:SGN:NCE TMO\n")); // Timeout waiting for nonce!
ret = false;
} else {
if (_signingNonceStatus == SIGN_OK) {
// process() received a nonce and signerProcessInternal successfully signed the message
msg = _msgSign; // Write the signed message back
SIGN_DEBUG(PSTR("SGN:SGN:SGN\n")); // Message to send has been signed
ret = true;
// After this point, only the 'last' member of the message structure is allowed to be
// altered if the message has been signed, or signature will become invalid and the
// message rejected by the receiver
} else {
SIGN_DEBUG(PSTR("!SGN:SGN:SGN FAIL\n")); // Message to send could not be signed!
ret = false;
}
}
}
}
@@ -256,11 +279,17 @@ bool signerVerifyMsg(MyMessage &msg)
SIGN_DEBUG(PSTR("!SGN:VER:NSG\n")); // Message is not signed, but it should have been!
verificationResult = false;
} else {
if (!signerBackendVerifyMsg(msg)) {
SIGN_DEBUG(PSTR("!SGN:VER:FAIL\n")); // Signature verification failed!
// Before starting, validate that our state is good, or signing will fail
if (!stateValid) {
SIGN_DEBUG(PSTR("!SGN:VER:STATE\n")); // Signing system is not in a valid state
verificationResult = false;
} else {
SIGN_DEBUG(PSTR("SGN:VER:OK\n"));
if (!signerBackendVerifyMsg(msg)) {
SIGN_DEBUG(PSTR("!SGN:VER:FAIL\n")); // Signature verification failed!
verificationResult = false;
} else {
SIGN_DEBUG(PSTR("SGN:VER:OK\n"));
}
}
#if defined(MY_NODE_LOCK_FEATURE)
if (verificationResult) {
@@ -533,3 +562,32 @@ static bool signerInternalProcessNonceResponse(MyMessage &msg)
#endif
return true; // No need to further process I_NONCE_RESPONSE
}
#if defined(MY_ENCRYPTION_FEATURE) || defined(MY_SIGNING_FEATURE)
static bool signerInternalValidatePersonalization(void)
{
#ifdef __linux__
// Personalization on linux is a bit more crude
return true;
#else
uint8_t buffer[32];
uint8_t* hash;
uint8_t checksum;
signerSha256Init();
hwReadConfigBlock((void*)buffer, (void*)EEPROM_SIGNING_SOFT_HMAC_KEY_ADDRESS, 32);
signerSha256Update(buffer, 32);
hwReadConfigBlock((void*)buffer, (void*)EEPROM_RF_ENCRYPTION_AES_KEY_ADDRESS, 16);
signerSha256Update(buffer, 16);
hwReadConfigBlock((void*)buffer, (void*)EEPROM_SIGNING_SOFT_SERIAL_ADDRESS, 9);
signerSha256Update(buffer, 9);
hash = signerSha256Final();
hwReadConfigBlock((void*)&checksum, (void*)EEPROM_PERSONALIZATION_CHECKSUM_ADDRESS, 1);
if (checksum != hash[0]) {
return false;
} else {
return true;
}
#endif
}
#endif
core/MySigning.h
+2
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@@ -790,10 +790,12 @@ int signerMemcmp(const void* a, const void* b, size_t sz);
* |!| SGN | SGN | SGN FAIL | Message failed to be signed
* | | SGN | SGN | NREQ='node' | 'node' does not require signed messages
* | | SGN | SGN | 'sender'!='us' NUS | Will not sign because 'sender' is not 'us' (repeater)
* |!| SGN | SGN | STATE | Security system in a invalid state (personalization data tampered)
* |!| SGN | VER | NSG | Message was not signed, but it should have been
* |!| SGN | VER | FAIL | Verification failed
* | | SGN | VER | OK | Verification succeeded
* | | SGN | VER | LEFT='number' | 'number' of failed verifications left in a row before node is locked
* |!| SGN | VER | STATE | Security system in a invalid state (personalization data tampered)
* | | SGN | SKP | MSG CMD='cmd',TYPE='type'| Message with command 'cmd' and type 'type' does not need to be signed
* | | SGN | SKP | ACK CMD='cmd',TYPE='type'| ACK messages does not need to be signed
* | | SGN | NCE | LEFT='number' | 'number' of nonce requests between successful verifications left before node is locked
core/MySigningAtsha204Soft.cpp
-27
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@@ -103,33 +103,6 @@ bool signerAtsha204SoftInit(void)
_signing_node_serial_info[8] = getNodeId();
}
#else
uint8_t buffer[32];
uint8_t* hash;
uint8_t checksum;
_signing_sha256.init();
hwReadConfigBlock((void*)buffer, (void*)EEPROM_SIGNING_SOFT_HMAC_KEY_ADDRESS, 32);
for (int i = 0; i < 32; i++) {
_signing_sha256.write(buffer[i]);
}
hwReadConfigBlock((void*)buffer, (void*)EEPROM_RF_ENCRYPTION_AES_KEY_ADDRESS, 16);
for (int i = 0; i < 16; i++) {
_signing_sha256.write(buffer[i]);
}
hwReadConfigBlock((void*)buffer, (void*)EEPROM_SIGNING_SOFT_SERIAL_ADDRESS, 9);
for (int i = 0; i < 9; i++) {
_signing_sha256.write(buffer[i]);
}
hash = _signing_sha256.result();
hwReadConfigBlock((void*)&checksum, (void*)EEPROM_PERSONALIZATION_CHECKSUM_ADDRESS, 1);
if (checksum != hash[0]) {
SIGN_DEBUG(PSTR("!SGN:PER:TAMPERED\n"));
init_ok = false;
} else {
SIGN_DEBUG(PSTR("SGN:PER:OK\n"));
init_ok = true;
}
if (init_ok) {
hwReadConfigBlock((void*)_signing_hmac_key, (void*)EEPROM_SIGNING_SOFT_HMAC_KEY_ADDRESS, 32);
hwReadConfigBlock((void*)_signing_node_serial_info, (void*)EEPROM_SIGNING_SOFT_SERIAL_ADDRESS, 9);