get password into memory

mempass.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>
#include <termios.h>

int main(void)
{
        char buf[BUFSIZ];
        register int input, len = 0;
        struct termios t_orig, t_new;
        int i;

        tcgetattr(STDIN_FILENO, &t_orig);
        t_new = t_orig;

        t_new.c_lflag &= ~ECHO;
        t_new.c_lflag &= ~ICANON;
        tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_new);

        printf("Enter password: ");
        fflush(stdout);
        while((input = fgetc(stdin)) != '\n') {
                buf[len++] = (input ^ 42);
                if(len >= sizeof(buf)-1)
                        break;
        }
        printf("\n");
        fflush(stdout);
        buf[len] = '\0';

        tcsetattr(STDIN_FILENO, TCSAFLUSH, &t_orig);

        for(i=0;i<len;++i) {
                printf("0x%02x (%c)", buf[i], isprint(buf[i]) ? buf[i] : '.');
        }
        printf("\n");

        for(i=0;i<len;++i) {
                printf("%c", buf[i] ^ 42);
        }
        printf("\n");

        return 0;
}

and read() can't use registers directly. (uses pointer to store buffer, which can't be a register)