path: root/src/readpassphrase.c

#include "readpassphrase.h"

#ifdef _WIN32
#include <windows.h>
#include <stdio.h>
#include <conio.h>

/*on error returns NULL and sets errno*/
wchar_t *
utf8_to_utf16(const char *utf8)
{
        int needed = 0;
        wchar_t* utf16 = NULL;
        if ((needed = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, NULL, 0)) == 0 ||
            (utf16 = malloc(needed * sizeof(wchar_t))) == NULL ||
            MultiByteToWideChar(CP_UTF8, 0, utf8, -1, utf16, needed) == 0) {
                printf("failed to convert utf8 payload:%s error:%li", utf8, GetLastError());
                errno = ENOMEM;
                return NULL;
        }

        return utf16;
}

char *readpassphrase(const char *prompt, char *outBuf, size_t outBufLen, int flags)
{
	int current_index = 0;
	char ch;
	wchar_t* wtmp = NULL;

	if (outBufLen == 0) {
		errno = EINVAL;
		return NULL;
	}

	while (_kbhit()) _getch();

	wtmp = utf8_to_utf16(prompt);
	if (wtmp == NULL)
		printf("unable to alloc memory");

	_cputws(wtmp);
	free(wtmp);

	while (current_index < outBufLen - 1) {
		ch = _getch();
		
		if (ch == '\r') {
			if (_kbhit()) _getch(); /* read linefeed if its there */
			break;
		} else if (ch == '\n') {
			break;
		} else if (ch == '\b') { /* backspace */
			if (current_index > 0) {
				if (flags & RPP_ECHO_ON)
					printf_s("%c \b", ch);

				current_index--; /* overwrite last character */
			}
		} else if (ch == '\003') { /* exit on Ctrl+C */
			printf("\n");
		} else {
			if (flags & RPP_SEVENBIT)
				ch &= 0x7f;

			if (isalpha((unsigned char)ch)) {
				if(flags & RPP_FORCELOWER)
					ch = tolower((unsigned char)ch);
				if(flags & RPP_FORCEUPPER)
					ch = toupper((unsigned char)ch);
			}

			outBuf[current_index++] = ch;
			if(flags & RPP_ECHO_ON)
				printf_s("%c", ch);
		}
	}

	outBuf[current_index] = '\0';
	_cputs("\n");

	return outBuf;
}

#else /* !_WIN32 */

#include <termios.h>
#include <signal.h>
#include <ctype.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <stdio.h>

#ifndef TCSASOFT
/* If we don't have TCSASOFT define it so that ORing it it below is a no-op. */
# define TCSASOFT 0
#endif

/* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
#if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
#  define _POSIX_VDISABLE       VDISABLE
#endif

static volatile sig_atomic_t signo[NSIG];

static void handler(int);

char *
readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
{
	ssize_t nr;
	int input, output, save_errno, i, need_restart;
	char ch, *p, *end;
	struct termios term, oterm;
	struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
	struct sigaction savetstp, savettin, savettou, savepipe;

	/* I suppose we could alloc on demand in this case (XXX). */
	if (bufsiz == 0) {
		errno = EINVAL;
		return(NULL);
	}

restart:
	for (i = 0; i < NSIG; i++)
		signo[i] = 0;
	nr = -1;
	save_errno = 0;
	need_restart = 0;
	
    /*
     * Fix strange behaviour: a file must be open to prevent echo
    */
    if (!(flags & RPP_ECHO_ON))
        open(_PATH_TTY, O_RDONLY);
    
    /*
	 * Read and write to /dev/tty if available.  If not, read from
	 * stdin and write to stderr unless a tty is required.
	 */
	if ((flags & RPP_STDIN) ||
	    (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
		if (flags & RPP_REQUIRE_TTY) {
			errno = ENOTTY;
			return(NULL);
		}
		input = STDIN_FILENO;
		output = STDERR_FILENO;
	}

	/*
	 * Turn off echo if possible.
	 * If we are using a tty but are not the foreground pgrp this will
	 * generate SIGTTOU, so do it *before* installing the signal handlers.
	 */
	if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
		memcpy(&term, &oterm, sizeof(term));
		if (!(flags & RPP_ECHO_ON))
			term.c_lflag &= ~(ECHO | ECHONL);
#ifdef VSTATUS
		if (term.c_cc[VSTATUS] != _POSIX_VDISABLE)
			term.c_cc[VSTATUS] = _POSIX_VDISABLE;
#endif
		(void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
	} else {
		memset(&term, 0, sizeof(term));
		term.c_lflag |= ECHO;
		memset(&oterm, 0, sizeof(oterm));
		oterm.c_lflag |= ECHO;
	}

	/*
	 * Catch signals that would otherwise cause the user to end
	 * up with echo turned off in the shell.  Don't worry about
	 * things like SIGXCPU and SIGVTALRM for now.
	 */
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = 0;		/* don't restart system calls */
	sa.sa_handler = handler;
    size_t writen = 0;
	(void)sigaction(SIGALRM, &sa, &savealrm);
	(void)sigaction(SIGHUP, &sa, &savehup);
	(void)sigaction(SIGINT, &sa, &saveint);
	(void)sigaction(SIGPIPE, &sa, &savepipe);
	(void)sigaction(SIGQUIT, &sa, &savequit);
	(void)sigaction(SIGTERM, &sa, &saveterm);
	(void)sigaction(SIGTSTP, &sa, &savetstp);
	(void)sigaction(SIGTTIN, &sa, &savettin);
	(void)sigaction(SIGTTOU, &sa, &savettou);

	if (!(flags & RPP_STDIN))
		writen = write(output, prompt, strlen(prompt));
    if(writen == 0) {
        printf("unable to prompt.");
    }
	end = buf + bufsiz - 1;
	p = buf;
	while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
		if (p < end) {
			if ((flags & RPP_SEVENBIT))
				ch &= 0x7f;
			if (isalpha((unsigned char)ch)) {
				if ((flags & RPP_FORCELOWER))
					ch = (char)tolower((unsigned char)ch);
				if ((flags & RPP_FORCEUPPER))
					ch = (char)toupper((unsigned char)ch);
			}
			*p++ = ch;
		}
	}
	*p = '\0';
	save_errno = errno;
	if (!(term.c_lflag & ECHO))
		writen = write(output, "\n", 1);

    if(writen == 0){
        printf("unable to echo.");
    }

	/* Restore old terminal settings and signals. */
	if (memcmp(&term, &oterm, sizeof(term)) != 0) {
		const int sigttou = signo[SIGTTOU];

		/* Ignore SIGTTOU generated when we are not the fg pgrp. */
		while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 &&
		    errno == EINTR && !signo[SIGTTOU])
			continue;
		signo[SIGTTOU] = sigttou;
	}
	(void)sigaction(SIGALRM, &savealrm, NULL);
	(void)sigaction(SIGHUP, &savehup, NULL);
	(void)sigaction(SIGINT, &saveint, NULL);
	(void)sigaction(SIGQUIT, &savequit, NULL);
	(void)sigaction(SIGPIPE, &savepipe, NULL);
	(void)sigaction(SIGTERM, &saveterm, NULL);
	(void)sigaction(SIGTSTP, &savetstp, NULL);
	(void)sigaction(SIGTTIN, &savettin, NULL);
	(void)sigaction(SIGTTOU, &savettou, NULL);
	if (input != STDIN_FILENO)
		(void)close(input);

	/*
	 * If we were interrupted by a signal, resend it to ourselves
	 * now that we have restored the signal handlers.
	 */
	for (i = 0; i < NSIG; i++) {
		if (signo[i]) {
			kill(getpid(), i);
			switch (i) {
			case SIGTSTP:
			case SIGTTIN:
			case SIGTTOU:
				need_restart = 1;
			}
		}
	}
	if (need_restart)
		goto restart;

	if (save_errno)
		errno = save_errno;
	return(nr == -1 ? NULL : buf);
}

#if 0
char *
getpass(const char *prompt)
{
	static char buf[_PASSWORD_LEN + 1];

	return(readpassphrase(prompt, buf, sizeof(buf), RPP_ECHO_OFF));
}
#endif

static void handler(int s)
{

	signo[s] = 1;
}

#endif /* !_WIN32 */