#include <stdio.h>
#include <string.h>
#include <stdlib.h>

// Convert a two-char hex string into the char it represents.
char x2c(char *what) {
	register char digit;
	digit = (what[0] >= 'A' ? ((what[0] & 0xdf) - 'A')+10 : (what[0] - '0'));
	digit *= 16;
	digit += (what[1] >= 'A' ? ((what[1] & 0xdf) - 'A')+10 : (what[1] - '0'));
	return(digit);
}


// Remove escape sequences
void unescape_url(char *url) {
	register int i,j;

	for(i=0,j=0; url[j]; ++i,++j) {
		if((url[i] = url[j]) == '%') {
			url[i] = x2c(&url[j+1]) ;
			j+= 2 ;
		}
	}
	url[i] = '\0' ;
}


// Create name-value pairs of given parameters and place them in a list
char **getcgivars() {
	register int i ;
	char *request_method ;
	int content_length;
	char *cgiinput ;
	char **cgivars ;
	char **pairlist ;
	int paircount ;
	char *nvpair ;
	char *eqpos ;

	// Depending on the request method, read all CGI input into cgiinput
	request_method= getenv("REQUEST_METHOD") ;

	if (!strcmp(request_method, "GET") || !strcmp(request_method, "HEAD") ) {
        	char *qs ;
		qs= getenv("QUERY_STRING") ;
		cgiinput= strdup(qs ? qs : "") ;
	}
	else if (!strcmp(request_method, "POST")) {
        /* strcasecmp() is not supported in Windows-- use strcmpi() instead */
        if ( strcasecmp(getenv("CONTENT_TYPE"), "application/x-www-form-urlencoded")) {
	    printf("Content-Type: text/plain\n\n") ;
            printf("getcgivars(): Unsupported Content-Type.\n") ;
            exit(1) ;
        }
        if ( !(content_length = atoi(getenv("CONTENT_LENGTH"))) ) {
	    printf("Content-Type: text/plain\n\n") ;
            printf("getcgivars(): No Content-Length was sent with the POST request.\n") ;
            exit(1) ;
        }
        if ( !(cgiinput= (char *) malloc(content_length+1)) ) {
	    printf("Content-Type: text/plain\n\n") ;
            printf("getcgivars(): Couldn't malloc for cgiinput.\n") ;
            exit(1) ;
        }
        if (!fread(cgiinput, content_length, 1, stdin)) {
	    printf("Content-Type: text/plain\n\n") ;
            printf("getcgivars(): Couldn't read CGI input from STDIN.\n") ;            exit(1) ;
        }
        cgiinput[content_length]='\0' ;
    }
    else {
	printf("Content-Type: text/plain\n\n") ;
        printf("getcgivars(): Unsupported REQUEST_METHOD.\n") ;
        exit(1) ;
    }

    /** Change all plusses back to spaces. **/
    for (i=0; cgiinput[i]; i++) if (cgiinput[i] == '+') cgiinput[i] = ' ' ;

    /** First, split on "&" and ";" to extract the name-value pairs into **/
    /** pairlist.  **/
    pairlist= (char **) malloc(256*sizeof(char **)) ;
    paircount= 0 ;
    nvpair= strtok(cgiinput, "&;") ;
    while (nvpair) {
        pairlist[paircount++]= strdup(nvpair) ;
        if (!(paircount%256))
            pairlist= (char **) realloc(pairlist,(paircount+256)*sizeof(char **)) ;
        nvpair= strtok(NULL, "&;") ;
    }
    pairlist[paircount]= 0 ; /* terminate the list with NULL */

    /** Then, from the list of pairs, extract the names and values. **/
    cgivars= (char **) malloc((paircount*2+1)*sizeof(char **)) ;
    for (i= 0; i<paircount; i++) {
        if (eqpos=strchr(pairlist[i], '=')) {
            *eqpos= '\0' ;
            unescape_url(cgivars[i*2+1]= strdup(eqpos+1)) ;
        } else {
            unescape_url(cgivars[i*2+1]= strdup("")) ;
        }
        unescape_url(cgivars[i*2]= strdup(pairlist[i])) ;
    }
    cgivars[paircount*2]= 0 ; /* terminate the list with NULL */

    /** Free anything that needs to be freed. **/
    free(cgiinput) ;
    for (i=0; pairlist[i]; i++) free(pairlist[i]) ;
    free(pairlist) ;

    /** Return the list of name-value strings. **/
    return cgivars ;

}

/***************** end of the getcgivars() module ********************/


bool isUser(char* user, char* pass){
	FILE *file = fopen ("userlist", "r" );
	char line [ 128 ];
	char cmpString[128] = "";
	strcat(cmpString,user);
	strcat(cmpString, ":");
	strcat(cmpString, pass);
	strcat(cmpString, "\n");
	while ( fgets ( line, sizeof line, file ) != NULL ) {
		if(!strcmp(line,cmpString)) {
			return true;
		}
	}
	fclose ( file );
	return false;
}


/** Standard "hello, world" program, that also shows all CGI input. **/ int main() {
    char **cgivars ;
    int i ;

    /** First, get the CGI variables into a list of strings **/
    cgivars= getcgivars() ;


    char *user = "";
    char *pass = "";

    for (i=0; cgivars[i]; i+= 2) {
	if(!strcmp(cgivars[i],"user")) {
		user = cgivars[i+1];
		continue;
	}
        if(!strcmp(cgivars[i],"pass")) {
                pass = cgivars[i+1];
		continue;
        }

    }
    if((strcmp(user, "") && strcmp(pass, ""))) {
	printf("%s", (isUser(user, pass))?"true":"false");

    }


    /** Free anything that needs to be freed **/
    for (i=0; cgivars[i]; i++) free(cgivars[i]) ;
    free(cgivars) ;

    exit(0) ;
}