void send_no_user(Bank *bank)
{
unsigned char *out = (unsigned char *)calloc(10000, sizeof(unsigned char));
char *response = (char *) calloc(3, sizeof(char));
response = "nouser";
do_crypt(bank, (unsigned char *)response, out, 1);
bank_send(bank, (char*) out, strlen((char *)out));
}
void handle_balance_atm(Bank* bank, char* args) {
char* tmp;
char send_msg[MAX_LINE_SIZE + 1];
memset(send_msg, 0, MAX_LINE_SIZE);
tmp = (char*)hash_table_find(bank->user_balance_ht, args);
printf("balance:%s\n", tmp);
strcat(send_msg, tmp);
bank_encrypt(bank, send_msg, strlen(send_msg));
bank_send(bank, send_msg, strlen(send_msg));
}
void handle_user_login(Bank* bank, char* args) {
char send_msg[MAX_LINE_SIZE + 1];
memset(send_msg, 0, MAX_LINE_SIZE);
if ((char*)hash_table_find(bank->user_balance_ht, args) == NULL ||
(char*)hash_table_find(bank->logged_user_ht, args) != NULL) {
strcat(send_msg, "NA");
} else {
strcat(send_msg, "OK");
hash_table_add(bank->logged_user_ht, args, "1");
}
bank_encrypt(bank, send_msg, strlen(send_msg));
bank_send(bank, send_msg, strlen(send_msg));
}
void handle_user_logout(Bank* bank, char* args) {
char send_msg[MAX_LINE_SIZE + 1];
memset(send_msg, 0, MAX_LINE_SIZE);
if ((char*)hash_table_find(bank->logged_user_ht, args) == NULL) {
strcat(send_msg, "No user logged in");
} else {
strcat(send_msg, "OK");
hash_table_del(bank->logged_user_ht, args);
}
bank_encrypt(bank, send_msg, strlen(send_msg));
bank_send(bank, send_msg, strlen(send_msg));
return;
}
void handle_withdraw(Bank* bank, char* args1, char* args2) {
char* tmp;
int balance;
int amt;
char send_msg[MAX_LINE_SIZE + 1];
memset(send_msg, 0, MAX_LINE_SIZE);
tmp = (char*)hash_table_find(bank->user_balance_ht, args1);
sscanf(tmp, "%d", &balance);
sscanf(args2, "%d", &amt);
if (balance < amt) {
strcat(send_msg, "IF");
} else {
strcat(send_msg, "AD");
balance -= amt;
memset(tmp, 0, 64);
sprintf(tmp, "%d", balance);
hash_table_add(bank->user_balance_ht, args1, tmp);
}
bank_encrypt(bank, send_msg, strlen(send_msg));
bank_send(bank, send_msg, strlen(send_msg));
}
int main(int argc, char**argv)
{
int n;
char sendline[10000];
char recvline[10000];
char key[32];
memset(key,'\0',32);
unsigned char decrypted[10000];
FILE *file;
//memset(recvline,'\0',10000);
//char user_input[1000];
file=fopen(argv[1],"r");
char *split=strtok(argv[1],".");
split=strtok(NULL,".");
if(file==0 || strcmp(split,"bank")) {
printf("Error opening ATM initialization file\n");
return 64;
}
fread(key,sizeof(key),32,file);
key[32]='\0';
//printf("bank file contents: %s\n",key);
HashTable *users = hash_table_create(100);
HashTable *balance = hash_table_create(100);
Bank *bank = bank_create();
//bank->users = list_create();
//bank->usr_key = hash_table_create(100);
//bank->usr_bal = hash_table_create(100);
printf("%s", prompt);
fflush(stdout);
while(1)
{
memset(decrypted,'\0',10000);
memset(recvline,'\0',10000);
//memset(sendline,'\0',10000);
fd_set fds;
FD_ZERO(&fds);
FD_SET(0, &fds);
FD_SET(bank->sockfd, &fds);
select(bank->sockfd+1, &fds, NULL, NULL, NULL);
if(FD_ISSET(0, &fds)) {
fgets(sendline, 10000,stdin);
bank_process_local_command(bank, sendline, strlen(sendline),users,balance);
printf("%s", prompt);
fflush(stdout);
} else if(FD_ISSET(bank->sockfd, &fds)) {
;
//int flag = 0;
n = bank_recv(bank, recvline, 10000);
//int flag=decrypt(recvline,key,decrypted,n);
if(!decrypt(recvline,key,decrypted,n)) { //this means that it has not been decrypted correctly so it will return a null packet
unsigned char encrypted[10000];
char packet[10000];
sprintf(packet,"<%s>",NULL);
int out_size =0;
encrypt(packet,key,encrypted,&out_size);
bank_send(bank, encrypted, out_size);
printf("%s", prompt);
fflush(stdout);
continue;
}
//printf("%s\n",decrypted);
char * message=strtok(decrypted,"\n");
bank_process_remote_command(bank, message, n, users,key,balance);
}
}
hash_table_free(balance);
hash_table_free(users); //never executes
bank_free(bank);
//fclose(file);
return EXIT_SUCCESS;
}
void bank_process_remote_command(Bank *bank, char *command, size_t len)
{
// TODO: Implement the bank side of the ATM-bank protocol
uint8_t opcode = *((uint8_t *) command);
char errM[] = {0,0};
if(opcode == 1){
int namelen;
char *name;
Node *user = NULL;
uint8_t *sendback = malloc(2);
namelen = *((uint32_t *)(command+1));
namelen = ntohl(namelen);
name = malloc(namelen + 1);
memcpy(name, command+5, namelen);
name[namelen] = 0;
user = get_client(bank->clientHead, name);
sendback[0] = 1;
if(user == NULL){
sendback[1] = 0;
}
else
sendback[1] = 1;
bank_send(bank, sendback, 2);
free(sendback);
}
else{
uint8_t *mesHash = command + len-32;
int messlen = len-33;
if(messlen > 5){
int namelen;
char *name;
uint8_t *data = malloc(messlen);
Node *user = NULL;
memcpy(data, command+1, messlen);
namelen = *((uint32_t *)data);
namelen = ntohl(namelen);
name = malloc(namelen + 1);
memcpy(name, data+4, namelen);
name[namelen] = 0;
user = get_client(bank->clientHead, name);
if(user != NULL){
EVP_MD_CTX *hashctx = EVP_MD_CTX_create();
uint8_t thehash[32];
int hashlen;
EVP_DigestInit_ex(hashctx, EVP_sha256(), NULL);
EVP_DigestUpdate(hashctx, user->PIN,4);
EVP_DigestUpdate(hashctx, data, messlen);
EVP_DigestFinal_ex(hashctx, thehash, &hashlen);
EVP_MD_CTX_destroy(hashctx);
if(compHash(thehash, mesHash) == 1){
if(opcode == 2){
uint8_t *sendback = malloc(2);
uint32_t with = *((uint32_t *)(data+namelen+4));
with = ntohl(with);
sendback[0] = 2;
if(with < user->balance){
user->balance = user->balance - with;
sendback[1] = 1;
}
else
sendback[1] = 0;
bank_send(bank, sendback, 2);
free(sendback);
}
else{
if(opcode == 3){
uint8_t *sendback = malloc(6);
uint32_t bal = htonl(user->balance);
sendback[0] = 3;
sendback[1] = 1;
memcpy(sendback + 2, &bal, 4);
bank_send(bank, sendback, 6);
free(sendback);
}
else{
bank_send(bank, errM, 2);
}
}
}
else{
bank_send(bank, errM, 2);
}
}
else{
bank_send(bank, errM, 2);
}
free(data);
}
else{
bank_send(bank, errM, 2);
}
}
}
void bank_process_remote_command(Bank *bank, char *command, size_t len)
{
// TODO: Implement the bank side of the ATM-bank protocol
/*
* The following is a toy example that simply receives a
* string from the ATM, prepends "Bank got: " and echoes
* it back to the ATM before printing it to stdout.
*/
FILE *fp;
char decrypted[1024];
char call[1024];
strtok(command, "\n");
// printf("cipher is: %s\n", command);
sprintf(call,"echo %s |openssl enc -aes-256-cbc -d -a -pass file:%s -salt",command,bank->symm_key);
fp =popen(call,"r");
memset(call,0x00,strlen(call));
if(fp!=NULL) {
const char space[] = " ";
static char begin_session[] = "begin-session";
static char withdraw[] = "withdraw";
static char balance[] = "balance";
fgets(decrypted,1024,fp);
char *token;
strtok(decrypted, "\n");
token = strtok(decrypted, space);
if (strcmp(token, begin_session) == 0) {
token = strtok(NULL, space);
char sendline[1024];
char response[4];
if (list_find(bank->users, token) == NULL)
sprintf(response, "%s", "no");
else
sprintf(response, "%s", "yes");
//To encrypt and make system call to create .card file
sprintf(call,"echo %s |openssl enc -aes-256-cbc -e -a -pass file:%s -salt -out %s",response, bank->symm_key,"temp.txt");
system(call);
memset(call,0x00,strlen(call));
FILE *dec;
char cipher[1024];
//open .card file and read in cipher
dec = fopen("temp.txt", "r");
fgets(cipher, 1024, (FILE*)dec);
strtok(cipher, "\n");
fclose(dec);
// printf("send cipher: %s\n", cipher);
bank_send(bank, cipher, strlen(cipher));
system("rm temp.txt");
} else if (strcmp(token, withdraw) == 0) {
char *user_name;
char *amount;
user_name = strtok(NULL, space);
amount = strtok(NULL, space);
char *ptr;
unsigned int withdraw_amt = strtoul(amount, &ptr, 10);
unsigned int *cur_b = list_find(bank->users, user_name);
char sendline[1024];
char response[4];
if (*cur_b >= withdraw_amt) {
unsigned int new_b = *cur_b - withdraw_amt;
*cur_b = new_b;
sprintf(response, "%s", "yes");
} else {
sprintf(response, "%s", "no");
}
//To encrypt and make system call to create .card file
sprintf(call,"echo %s |openssl enc -aes-256-cbc -e -a -pass file:%s -salt -out %s",response, bank->symm_key,"temp.txt");
system(call);
memset(call,0x00,strlen(call));
FILE *dec;
char cipher[1024];
//open .card file and read in cipher
dec = fopen("temp.txt", "r");
fgets(cipher, 1024, (FILE*)dec);
strtok(cipher, "\n");
fclose(dec);
// printf("cipher is: %s\n", cipher);
bank_send(bank, cipher, strlen(cipher));
system("rm temp.txt");
} else if (strcmp(token, balance) == 0){
char *user_name;
char response[1024];
user_name = strtok(NULL, space);
unsigned int *cur_b = list_find(bank->users, user_name);
sprintf(response, "%u", *cur_b);
// printf("response is: %s\n", response);
//To encrypt and make system call to create .card file
sprintf(call,"echo %s |openssl enc -aes-256-cbc -e -a -pass file:%s -salt -out %s", response, bank->symm_key,"temp.txt");
system(call);
memset(call,0x00,strlen(call));
FILE *dec;
char cipher[1024];
//open .card file and read in cipher
dec = fopen("temp.txt", "r");
fgets(cipher, 1024, (FILE*)dec);
strtok(cipher, "\n");
fclose(dec);
// printf("cipher is: %s\n", cipher);
bank_send(bank, cipher, strlen(cipher));
system("rm temp.txt");
}
memset(decrypted,0x00,strlen(decrypted));
// if (strcmp())
// printf("name and amount are: %s",decrypted);
}else {
printf("Error couldn't open .card file");
}
pclose(fp);
/*
char sendline[4];
memset(sendline, 0x00, strlen(sendline));
command[len]=0;
strtok(command, "\n");
if (list_find(bank->users, command) == NULL)
sprintf(sendline, "%s", "no");
else
sprintf(sendline, "%s", "yes");
bank_send(bank, sendline, strlen(sendline));
// printf("Received the following:\n");
// fputs(command, stdout);
*/
}
void send_balance(Bank *bank, char *bal)
{
unsigned char *out = (unsigned char *)calloc(10000, sizeof(unsigned char));
do_crypt(bank, (unsigned char *)bal, out, 1);
bank_send(bank, (char*) out, strlen((char *)out));
}