void
substitute_back (command_t cmd, char * subs_from,char* subs_with)
{
if (cmd->type != SIMPLE_COMMAND)
{
substitute_back (cmd->u.command[0], subs_from, subs_with);
substitute_back (cmd->u.command[1], subs_from, subs_with);
if (cmd->u.command[2] != NULL)
substitute_back (cmd->u.command[2], subs_from, subs_with);
}
else
{
int i=0;
char* tmp = cmd->u.word[i];
while(tmp != NULL)
{
if (strcmp (tmp, subs_from) == 0)
{
tmp[0]='$';
strcpy (tmp+1, subs_with);
}
i++;
tmp = cmd->u.word[i];
}
}
}
void
execute_for_command(command_t c)
{
if (c->u.command[0]->type != SIMPLE_COMMAND)
error (1,0, "for command condition error.");
int i=0;
char* tmp = c->u.command[0]->u.word[i];
while (tmp != NULL && strcmp (tmp, "in")!=0)
{
i++;
tmp = c->u.command[0]->u.word[i];
}
if (tmp != NULL) //tmp == "in"
{
char* variable = c->u.command[0]->u.word[i-1];
i++;
tmp = c->u.command[0]->u.word[i];
while (tmp != NULL)
{
substitute_tokens (c->u.command[1], variable, tmp);
execute_command (c->u.command[1],0);
substitute_back (c->u.command[1], tmp, variable);
c->status = c->u.command[1]->status;
i++;
tmp = c->u.command[0]->u.word[i];
}
}
else //tmp == NULL
error (1,0,"Syntax error: missing in token in for command.");
}
/* Interaction with the server */
void Talk_to_server ( int cfd ,char* agrv_filename)
{
char str[STACK_SIZE],str_concat[STACK_SIZE];
int x, e;
FILE *fptr1;
key pub_key, pvt_key;
//char ch;
char buffer[MAX_LEN];
int nbytes, status;
int src_addr, dest_addr;
long int plaintext, ciphertext, deciphertext;
KeyGeneration(&pub_key, &pvt_key);
ReqMsg send_msg;
RepMsg recv_msg;
//key_public public_key;
// printf("\n Public Key of Alice is (n,e): (%ld , %ld)\n\r", pub_key.public_key.n, pub_key.public_key.e);
printf("\n Private key of Alice is (n,d): (%ld , %ld)\n\r", pvt_key.private_key.n,
pvt_key.private_key.d);
dest_addr = inet_addr(DEFAULT_SERVER);
src_addr = inet_addr("127.0.0.5");
printf("Sending the public_key to the server\n");
Msg msg;
msg.hdr.opcode=Pubkey;
msg.hdr.src_addr = src_addr;
msg.hdr.dest_addr = dest_addr;
msg.AllMsg.pubkey.n=pub_key.public_key.n;
msg.AllMsg.pubkey.e=pub_key.public_key.e;
int t_block=66,n_block=0;
while(t_block<pub_key.public_key.n)
{
t_block=66+t_block*100;
++n_block;
}
status = send(cfd, &msg, sizeof(Msg), 0);
if (status == -1) {
fprintf(stderr, "*** Server error: unable to send\n");
return;
}
/* send the request message REQ to the server */
printf("Sending the request message REQ to the server\n");
msg.hdr.opcode = REQ;
msg.hdr.src_addr = src_addr;
msg.hdr.dest_addr = dest_addr;
strcpy(msg.AllMsg.req.filename, agrv_filename);
//printf("here\n");
printf("File name is:- %s\n",msg.AllMsg.req.filename);
status = send(cfd, &msg, sizeof(Msg), 0);
if (status == -1) {
fprintf(stderr, "*** Server error: unable to send\n");
return;
}
//exit(0);
while (1) {
/* receive greetings from server */
nbytes = recv(cfd, &msg, sizeof(Msg), 0);
if (nbytes == -1) {
fprintf(stderr, "*** Client error: unable to receive\n");
}
switch ( msg.hdr.opcode ) {
case REP :
sprintf(str,"%ld",DecryptionAlgorithm(msg.AllMsg.rep.chyp,pvt_key));
if(strlen(str)%2==1)
{
strcpy(str_concat,"0");
strcat(str_concat,str);
strcpy(str,str_concat);
}
if(strlen(str)/(2*n_block)!=1)
{
strcpy(str_concat,"00");
strcat(str_concat,str);
strcpy(str,str_concat);
}
/*printf("\nsha1 is:");
int loop_print;
for (loop_print = 0; loop_print < SHA_DIGEST_LENGTH; ++loop_print)
{
printf("%u",msg.sha1_send[loop_print] );
}*/
//printf("final %s\n",str);
substitute_back(str);
//printf("sha1 for sub%s\n",string_sha1);
unsigned char digest[SHA_DIGEST_LENGTH];
memset(digest,'\0',SHA_DIGEST_LENGTH);
/*int x;
for (x= 0; x < strlen(string_sha1); ++x)
{
printf("string[%d]%c",x,string_sha1[x] );
}
printf("\n");*/
//printf("size : %d\nText : #%s#", strlen(string_sha1), string_sha1);
SHA1(string_sha1,strlen(string_sha1),digest);
int for_loop;
/* for (i=0; i < SHA_DIGEST_LENGTH; i++) {
sprintf((char*)&(buf[i*2]), "%02x", temp[i]);
}*/
for (for_loop = 0; for_loop < SHA_DIGEST_LENGTH; ++for_loop)
{
if(msg.sha1_send[for_loop]!=digest[for_loop])
{
msg.hdr.opcode=Disc;
msg.AllMsg.disconnect.status=1;
status = send(cfd, &msg, sizeof(Msg), 0);
if (status == -1) {
fprintf(stderr, "hi Server error: unable to send\n");
return;
}
}
}
memset(string_sha1,'\0',strlen(string_sha1));
//printf("\n");
//printf("substitute after %s\n", string_substitute);
//printf("plaintext : %ld\n",plain);
/* Check the status of REP message */
/* if (msg.AllMsg.r.status)
printf("Message REQ has received successfully by the server\n");
else
printf("Message REQ has NOT received successfully by the server\n");*/
break;
case REQCOM:
if(msg.AllMsg.reqcom.status==1)
{
msg.hdr.opcode=Disc;
msg.AllMsg.disconnect.status=1;
fptr1 = fopen(agrv_filename,"w");
if (fptr1 == NULL)
printf("Error in writing to the file\n");
fprintf(fptr1, "%s", string_substitute);
fclose(fptr1);
}
printf("file recived complted doing deciphertext opcode is Disconnect: %d\n", msg.hdr.opcode);
status = send(cfd, &msg, sizeof(Msg), 0);
if (status == -1) {
printf("Disconnect client opcode: %d\n", msg.hdr.opcode);
exit(0);
}
//exit(0);
break;
case Disc :
printf("Disconnect client opcode: %d\n", msg.hdr.opcode);
exit(0);
break;
default:
//printf("default\n");
printf("message received with opcode: %d\n", msg.hdr.opcode);
exit(0);
}
}
}
