#include #include #include #include #include #include typedef struct { char deviceId[sizeof(((t_configBlock*)0)->deviceId)]; char sharedSecret[sizeof(((t_configBlock*)0)->sharedSecret)]; } t_device; const t_device devices[] = { { .deviceId = "MainsCnt01", .sharedSecret = "sharedSecretGanzGeheim" }, { .deviceId = "", .sharedSecret = "" } }; int main() { int sockfd; struct sockaddr_in servaddr, cliaddr; socklen_t cliaddrlen = sizeof(cliaddr); sockfd = socket(AF_INET, SOCK_DGRAM, 0); memset(&servaddr, 0, sizeof(servaddr)); servaddr.sin_family = AF_INET; servaddr.sin_addr.s_addr = htonl(INADDR_ANY); servaddr.sin_port = htons(20169); bind(sockfd, (const struct sockaddr *) &servaddr, sizeof(servaddr)); t_minuteBuffer buf; while (1) { int n = recvfrom(sockfd, buf.b, sizeof(buf.b), MSG_TRUNC, (struct sockaddr *) &cliaddr, &cliaddrlen); printf("received %d octets from %04x\n", n, cliaddr.sin_addr.s_addr); if (n != sizeof(buf.b)) { printf("Illegal packet size: %d\n", n); continue; } uint8_t i = 0; while (1) { if (strlen(devices[i].deviceId) == 0) { break; } if (strncmp(devices[i].deviceId, buf.s.deviceId, sizeof(((t_configBlock*)0)->deviceId)) == 0) { printf("Device found: %s\n", devices[i].deviceId); uint8_t receivedHash[SHA256_BLOCK_SIZE]; memcpy(receivedHash, buf.s.hash, SHA256_BLOCK_SIZE); memcpy(buf.s.hash, devices[i].sharedSecret, SHA256_BLOCK_SIZE); printf("recv. hash, 1. half is %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n", receivedHash[0], receivedHash[1], receivedHash[2], receivedHash[3], receivedHash[4], receivedHash[5], receivedHash[6], receivedHash[7], receivedHash[8], receivedHash[9], receivedHash[10], receivedHash[11], receivedHash[12], receivedHash[13], receivedHash[14], receivedHash[15] ); printf("recv. hash, 2. half is %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n", receivedHash[16], receivedHash[17], receivedHash[18], receivedHash[19], receivedHash[20], receivedHash[21], receivedHash[22], receivedHash[23], receivedHash[24], receivedHash[25], receivedHash[26], receivedHash[27], receivedHash[28], receivedHash[29], receivedHash[30], receivedHash[31] ); SHA256_CTX ctx; uint8_t calculatedHash[SHA256_BLOCK_SIZE]; sha256_init(&ctx); sha256_update(&ctx, buf.b, sizeof(buf.b)); sha256_final(&ctx, calculatedHash); printf("calc. hash, 1. half is %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n", calculatedHash[0], calculatedHash[1], calculatedHash[2], calculatedHash[3], calculatedHash[4], calculatedHash[5], calculatedHash[6], calculatedHash[7], calculatedHash[8], calculatedHash[9], calculatedHash[10], calculatedHash[11], calculatedHash[12], calculatedHash[13], calculatedHash[14], calculatedHash[15] ); printf("calc. hash, 2. half is %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x\n", calculatedHash[16], calculatedHash[17], calculatedHash[18], calculatedHash[19], calculatedHash[20], calculatedHash[21], calculatedHash[22], calculatedHash[23], calculatedHash[24], calculatedHash[25], calculatedHash[26], calculatedHash[27], calculatedHash[28], calculatedHash[29], calculatedHash[30], calculatedHash[31] ); if (memcmp(receivedHash, calculatedHash, SHA256_BLOCK_SIZE) != 0) { printf("Invalid hash\n"); } printf("DeviceId: %s\n", buf.s.deviceId); printf("Location: %s\n", buf.s.location); for (uint8_t j = 0; j < SECONDS_PER_MINUTE; j++) { printf("Time: %lu, Frequency: %u\n", buf.s.events[j].timestamp, buf.s.events[j].frequency); } printf("\n"); break; } else { printf("Unknown device\n"); } i++; } } }