int getSessionData(uint8_t *dst, uip_ipaddr_t *addr, SessionDataType type) {
int i = getIndexOf(addr);
if (i == -1) {
PRINTF("getSessionData: Keine Daten zur gesuchten IP gefunden\n");
return -1;
}
uint16_t epo_buf;
uint32_t num_buf;
Session_t *s = (Session_t *) RES_SESSION_LIST;
switch (type) {
case session_id:
nvm_getVar(dst, (fpoint_t) &s[i].session, 8);
return 8;
case session_epoch:
nvm_getVar(&epo_buf, (fpoint_t) &s[i].epoch, 2);
epo_buf = uip_htons(epo_buf);
memcpy(dst, &epo_buf, 2);
return 2;
case session_key:
nvm_getVar(dst, (fpoint_t) &s[i].private_key, 32);
return 32;
case session_num_write:
num_buf = uip_htonl(seq_num_w[i]);
memcpy(dst + 2, &num_buf, 4);
seq_num_w[i]++;
return 6;
}
return 0;
}
__attribute__((always_inline)) static void checkEpochIncrease(unsigned int index, uint16_t epoch) {
epoch--;
Session_t *s = (Session_t *) RES_SESSION_LIST;
if (nvm_cmp(&epoch, (fpoint_t) &s[index].epoch, 2) == 0) {
PRINTF("Daten vor Epoch-Increase:\n");
PRINTSESSION(index);
epoch++;
nvm_setVar(&epoch, (fpoint_t) &s[index].epoch, 2);
uint8_t buf[2 * sizeof(KeyBlock_t)];
KeyBlock_t *kb = (KeyBlock_t *) RES_KEY_BLOCK_LIST;
nvm_getVar(buf, (fpoint_t) &kb[(2 * index) + 1], sizeof(KeyBlock_t));
memset(buf + sizeof(KeyBlock_t), 0, sizeof(KeyBlock_t));
nvm_setVar(buf, (fpoint_t) &kb[2 * index], 2 * sizeof(KeyBlock_t));
seq_num_r[index] = 1;
seq_num_w[index] = 1;
PRINTF("Daten nach Epoch-Increase:\n");
PRINTSESSION(index);
// TODO aktivieren: newPSK();
}
}
int createSession(uint32_t *buf, uip_ipaddr_t *addr) {
uint32_t i;
Session_t *session = (Session_t *) (buf + 8);
Session_t *s = (Session_t *) RES_SESSION_LIST; // Pointer auf Flashspeicher
int index = getIndexOf(addr);
// Ein neuer private Key für ECDH wird in jedem Fall generiert
nvm_getVar(buf, RES_ECC_ORDER, LEN_ECC_ORDER);
#if DEBUG
printf("ECC_ORDER: ");
for (i = 0; i < 8; i++) printf("%08X", uip_htonl(buf[i]));
printf("\n");
#endif
do {
random_x((uint8_t *) session->private_key, 32);
} while (!ecc_is_valid_key(session->private_key, buf));
// Falls schon ein Eintrag existiert wird die Session durch
// setzten des neuen private Keys weiterentwickelt. Ansonsten
// wird alles gesetzt.
if (index >= 0) {
nvm_setVar(session->private_key, (fpoint_t) s[index].private_key, 32);
PRINTF("Session aktualisiert:\n");
PRINTSESSION(index);
} else {
index = getIndexOf(NULL);;
if (index < 0)
return -1;
uip_ipaddr_copy(&session->addr, addr);
for (i = 0; i < 8; i++) {
nvm_getVar(session->session + i, RES_ANSCHARS + (random_8() & 0x3F), 1);
} // TODO session-id auf doppel prüfen
session->epoch = 0;
session->valid = 1;
nvm_setVar(session, (fpoint_t) &s[index], sizeof(Session_t));
PRINTF("Session erstellt:\n");
PRINTSESSION(index);
seq_num_r[index] = 1;
seq_num_w[index] = 1;
}
return 0;
}
void poti_resource_handler(void* request, void* response, uint8_t *buffer, uint16_t preferred_size, int32_t *offset) {
int length = 0;
int result = (poti.value(0) * 100) / 35;
uint8_t source_string[LEN_SENML_VAL]; // {"bn":"/val","bu":"%%","e":[{"v":"%d.%d"}]}
nvm_getVar(source_string, RES_SENML_VAL, LEN_SENML_VAL);
length = snprintf(buffer, REST_MAX_CHUNK_SIZE, source_string, result / 100, result % 100 );
REST.set_header_content_type(response, REST.type.TEXT_PLAIN);
REST.set_response_payload(response, buffer, length);
}
void printSession(uint8_t index) {
uint8_t i;
uint8_t buffer[sizeof(Session_t)];
Session_t *session = (Session_t *) buffer;
Session_t *s = (Session_t *) RES_SESSION_LIST;
nvm_getVar(buffer, (fpoint_t) &s[index], sizeof(Session_t));
printf(" Index: %u \n Session-ID: %.*s\n IP: ", index, 8, session->session);
for (i = 0; i < 16; i++) printf("%02X", ((uint8_t *) &session->addr)[i]);
printf("\n Epoch: %u\n Valid: %u\n Private-Key: ", session->epoch, session->valid);
for (i = 0; i < 8; i++) printf("%08X", uip_htonl(session->private_key[i]));
printf("\n Sequenznummer: Read: %u Write %u", seq_num_r[index], seq_num_w[index]);
KeyBlock_t *kb = (KeyBlock_t *) RES_KEY_BLOCK_LIST;
nvm_getVar(buffer, (fpoint_t) &kb[2 * index], sizeof(KeyBlock_t));
printf("\n Key-Block 1: ");
for (i = 0; i < sizeof(KeyBlock_t); i++) printf("%02X", buffer[i]);
nvm_getVar(buffer, (fpoint_t) &kb[(2 * index) + 1], sizeof(KeyBlock_t));
printf("\n Key-Block 2: ");
for (i = 0; i < sizeof(KeyBlock_t); i++) printf("%02X", buffer[i]);
printf("\n");
}
