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Support encrypted meters and added vcc offset

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This commit is contained in:
Gunnar Skjold
2020-07-31 10:15:11 +02:00
parent 47ddf57547
commit 620e355a27
36 changed files with 12041 additions and 137 deletions
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96
lib/HanReader/src/HanReader.cpp
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@@ -1,4 +1,5 @@
#include "HanReader.h"
#include "mbedtls/gcm.h"
HanReader::HanReader() {
// Central European Time (Frankfurt, Paris)
@@ -16,11 +17,19 @@ void HanReader::setup(Stream *hanPort, RemoteDebug *debug)
if (debug) debug->println("MBUS serial setup complete");
}
void HanReader::setup(Stream *hanPort)
{
void HanReader::setup(Stream *hanPort){
setup(hanPort, NULL);
}
void HanReader::setEncryptionKey(uint8_t* encryption_key) {
memcpy(this->encryption_key, encryption_key, 16);
}
void HanReader::setAuthenticationKey(uint8_t* authentication_key) {
memcpy(this->authentication_key, authentication_key, 16);
}
bool HanReader::read(byte data) {
if (reader.Read(data)) {
bytesRead = reader.GetRawData(buffer, 0, 512);
@@ -40,16 +49,33 @@ bool HanReader::read(byte data) {
return false;
}
else if (
buffer[0] != 0xE6 ||
buffer[1] != 0xE7 ||
buffer[2] != 0x00 ||
buffer[3] != 0x0F
buffer[0] != 0xE6
|| buffer[1] != 0xE7
|| buffer[2] != 0x00
//|| buffer[3] != 0x0F
)
{
printW("Invalid HAN data: Start should be E6 E7 00 0F");
printW("Invalid HAN data: Start should be E6 E7 00");
return false;
}
// Have not found any documentation supporting this, but 0x0F for all norwegian meters.
// Danish meters with encryption has 0xDB, so lets assume this has something to do with that.
switch(buffer[3]) {
case 0x0F:
dataHeader = 8;
break;
case 0xDB:
printI("Decrypting frame");
if(!decryptFrame()) return false;
if (debugger->isActive(RemoteDebug::DEBUG)) {
printD("Data after decryption:");
debugPrint(buffer, 0, bytesRead);
}
dataHeader = 26;
break;
}
listSize = getInt(0, buffer, 0, bytesRead);
printI("HAN data is valid, listSize: %d", listSize);
return true;
@@ -58,6 +84,62 @@ bool HanReader::read(byte data) {
return false;
}
const size_t headersize = 3;
const size_t footersize = 0;
mbedtls_gcm_context m_ctx;
bool HanReader::decryptFrame() {
uint8_t system_title[8];
memcpy(system_title, buffer + headersize + 2, 8);
if (debugger->isActive(RemoteDebug::DEBUG)) {
printD("System title:");
debugPrint(system_title, 0, 8);
}
uint8_t initialization_vector[12];
memcpy(initialization_vector, system_title, 8);
memcpy(initialization_vector + 8, buffer + headersize + 14, 4);
if (debugger->isActive(RemoteDebug::DEBUG)) {
printD("Initialization vector:");
debugPrint(initialization_vector, 0, 12);
}
uint8_t additional_authenticated_data[17];
memcpy(additional_authenticated_data, buffer + headersize + 13, 1);
memcpy(additional_authenticated_data + 1, authentication_key, 16);
if (debugger->isActive(RemoteDebug::DEBUG)) {
printD("Additional authenticated data:");
debugPrint(additional_authenticated_data, 0, 12);
}
uint8_t authentication_tag[12];
memcpy(authentication_tag, buffer + headersize + bytesRead - headersize - footersize - 12, 12);
if (debugger->isActive(RemoteDebug::DEBUG)) {
printD("Authentication tag:");
debugPrint(authentication_tag, 0, 12);
}
uint8_t cipher_text[bytesRead - headersize - footersize - 18 - 12];
memcpy(cipher_text, buffer + headersize + 18, bytesRead - headersize - footersize - 12 - 18);
mbedtls_gcm_init(&m_ctx);
int success = mbedtls_gcm_setkey(&m_ctx, MBEDTLS_CIPHER_ID_AES, encryption_key, sizeof(encryption_key)*8);
if (0 != success ) {
printE("Setkey failed: " + String(success));
return false;
}
success = mbedtls_gcm_auth_decrypt(&m_ctx, sizeof(cipher_text), initialization_vector, sizeof(initialization_vector),
additional_authenticated_data, sizeof(additional_authenticated_data), authentication_tag, sizeof(authentication_tag),
cipher_text, buffer + headersize + 18);
if (0 != success) {
printE("authdecrypt failed: " + String(success));
return false;
}
mbedtls_gcm_free(&m_ctx);
return true;
}
void HanReader::debugPrint(byte *buffer, int start, int length) {
for (int i = start; i < start + length; i++) {
if (buffer[i] < 0x10)