passphrase.c

 
#include <winpr/environment.h>
 
#include <freerdp/config.h>
#include <freerdp/freerdp.h>
 
#include <errno.h>
#include <freerdp/utils/passphrase.h>
 
#ifdef _WIN32
 
#include <stdio.h>
#include <io.h>
#include <conio.h>
#include <wincred.h>
 
static char read_chr(FILE* f)
{
  char chr;
  const BOOL isTty = _isatty(_fileno(f));
  if (isTty)
    return fgetc(f);
  if (fscanf_s(f, "%c", &chr, (UINT32)sizeof(char)) && !feof(f))
    return chr;
  return 0;
}
 
int freerdp_interruptible_getc(rdpContext* context, FILE* f)
{
  return read_chr(f);
}
 
const char* freerdp_passphrase_read(rdpContext* context, const char* prompt, char* buf,
                                    size_t bufsiz, int from_stdin)
{
  WCHAR UserNameW[CREDUI_MAX_USERNAME_LENGTH + 1] = { 'p', 'r', 'e', 'f', 'i',
                                                    'l', 'l', 'e', 'd', '\0' };
  WCHAR PasswordW[CREDUI_MAX_PASSWORD_LENGTH + 1] = { 0 };
  BOOL fSave = FALSE;
  DWORD dwFlags = 0;
  WCHAR* promptW = ConvertUtf8ToWCharAlloc(prompt, NULL);
  const DWORD status =
      CredUICmdLinePromptForCredentialsW(promptW, NULL, 0, UserNameW, ARRAYSIZE(UserNameW),
                                         PasswordW, ARRAYSIZE(PasswordW), &fSave, dwFlags);
  free(promptW);
  if (ConvertWCharNToUtf8(PasswordW, ARRAYSIZE(PasswordW), buf, bufsiz) < 0)
    return NULL;
  return buf;
}
 
#elif !defined(ANDROID)
 
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <termios.h>
#include <unistd.h>
#include <freerdp/utils/signal.h>
 
#if defined(WINPR_HAVE_POLL_H) && !defined(__APPLE__)
#include <poll.h>
#else
#include <time.h>
#include <sys/select.h>
#endif
 
static int wait_for_fd(int fd, int timeout)
{
  int status = 0;
#if defined(WINPR_HAVE_POLL_H) && !defined(__APPLE__)
  struct pollfd pollset = { 0 };
  pollset.fd = fd;
  pollset.events = POLLIN;
  pollset.revents = 0;
 
  do
  {
    status = poll(&pollset, 1, timeout);
  } while ((status < 0) && (errno == EINTR));
 
#else
  fd_set rset = { 0 };
  struct timeval tv = { 0 };
  FD_ZERO(&rset);
  FD_SET(fd, &rset);
 
  if (timeout)
  {
    tv.tv_sec = timeout / 1000;
    tv.tv_usec = (timeout % 1000) * 1000;
  }
 
  do
  {
    status = select(fd + 1, &rset, NULL, NULL, timeout ? &tv : NULL);
  } while ((status < 0) && (errno == EINTR));
 
#endif
  return status;
}
 
static void replace_char(char* buffer, size_t buffer_len, const char* toreplace)
{
  while (*toreplace != '\0')
  {
    char* ptr = NULL;
    while ((ptr = strrchr(buffer, *toreplace)) != NULL)
      *ptr = '\0';
    toreplace++;
  }
}
 
static const char* freerdp_passphrase_read_tty(rdpContext* context, const char* prompt, char* buf,
                                               size_t bufsiz, int from_stdin)
{
  BOOL terminal_needs_reset = FALSE;
  char term_name[L_ctermid] = { 0 };
 
  FILE* fout = NULL;
 
  if (bufsiz == 0)
  {
    errno = EINVAL;
    return NULL;
  }
 
  ctermid(term_name);
  int terminal_fildes = 0;
  if (from_stdin || (strcmp(term_name, "") == 0))
  {
    fout = stdout;
    terminal_fildes = STDIN_FILENO;
  }
  else
  {
    const int term_file = open(term_name, O_RDWR);
    if (term_file < 0)
    {
      fout = stdout;
      terminal_fildes = STDIN_FILENO;
    }
    else
    {
      fout = fdopen(term_file, "w");
      if (!fout)
      {
        close(term_file);
        return NULL;
      }
      terminal_fildes = term_file;
    }
  }
 
  struct termios orig_flags = { 0 };
  if (tcgetattr(terminal_fildes, &orig_flags) != -1)
  {
    struct termios new_flags = { 0 };
    new_flags = orig_flags;
    new_flags.c_lflag &= (uint32_t)~ECHO;
    new_flags.c_lflag |= ECHONL;
    terminal_needs_reset = TRUE;
    if (tcsetattr(terminal_fildes, TCSAFLUSH, &new_flags) == -1)
      terminal_needs_reset = FALSE;
  }
 
  FILE* fp = fdopen(terminal_fildes, "r");
  if (!fp)
    goto error;
 
  (void)fprintf(fout, "%s", prompt);
  (void)fflush(fout);
 
  char* ptr = NULL;
  size_t ptr_len = 0;
 
  const SSIZE_T res = freerdp_interruptible_get_line(context, &ptr, &ptr_len, fp);
  if (res < 0)
    goto error;
  replace_char(ptr, ptr_len, "\r\n");
 
  strncpy(buf, ptr, MIN(bufsiz, ptr_len));
  free(ptr);
  if (terminal_needs_reset)
  {
    if (tcsetattr(terminal_fildes, TCSAFLUSH, &orig_flags) == -1)
      goto error;
  }
 
  if (terminal_fildes != STDIN_FILENO)
  {
    if (fclose(fp) == -1)
      goto error;
  }
 
  return buf;
 
error:
{
  int saved_errno = errno;
  if (terminal_needs_reset)
    (void)tcsetattr(terminal_fildes, TCSAFLUSH, &orig_flags);
 
  if (terminal_fildes != STDIN_FILENO)
  {
    if (fp)
      (void)fclose(fp);
  }
  errno = saved_errno;
  return NULL;
}
}
 
static const char* freerdp_passphrase_read_askpass(const char* prompt, char* buf, size_t bufsiz,
                                                   char const* askpass_env)
{
  char command[4096] = { 0 };
 
  (void)sprintf_s(command, sizeof(command), "%s 'FreeRDP authentication\n%s'", askpass_env,
                  prompt);
  // NOLINTNEXTLINE(clang-analyzer-optin.taint.GenericTaint)
  FILE* askproc = popen(command, "r");
  if (!askproc)
    return NULL;
  WINPR_ASSERT(bufsiz <= INT32_MAX);
  if (fgets(buf, (int)bufsiz, askproc) != NULL)
    buf[strcspn(buf, "\r\n")] = '\0';
  else
    buf = NULL;
  const int status = pclose(askproc);
  if (!WIFEXITED(status) || WEXITSTATUS(status) != 0)
    buf = NULL;
 
  return buf;
}
 
const char* freerdp_passphrase_read(rdpContext* context, const char* prompt, char* buf,
                                    size_t bufsiz, int from_stdin)
{
  const char* askpass_env = getenv("FREERDP_ASKPASS");
 
  if (askpass_env)
    return freerdp_passphrase_read_askpass(prompt, buf, bufsiz, askpass_env);
  else
    return freerdp_passphrase_read_tty(context, prompt, buf, bufsiz, from_stdin);
}
 
int freerdp_interruptible_getc(rdpContext* context, FILE* f)
{
  int rc = EOF;
  const int fd = fileno(f);
 
  const int orig = fcntl(fd, F_GETFL);
  (void)fcntl(fd, F_SETFL, orig | O_NONBLOCK);
  do
  {
    const int res = wait_for_fd(fd, 10);
    if (res != 0)
    {
      char c = 0;
      const ssize_t rd = read(fd, &c, 1);
      if (rd == 1)
        rc = (int)c;
      break;
    }
  } while (!freerdp_shall_disconnect_context(context));
 
  (void)fcntl(fd, F_SETFL, orig);
  return rc;
}
 
#else
 
const char* freerdp_passphrase_read(rdpContext* context, const char* prompt, char* buf,
                                    size_t bufsiz, int from_stdin)
{
  return NULL;
}
 
int freerdp_interruptible_getc(rdpContext* context, FILE* f)
{
  return EOF;
}
#endif
 
SSIZE_T freerdp_interruptible_get_line(rdpContext* context, char** plineptr, size_t* psize,
                                       FILE* stream)
{
  int c = 0;
  char* n = NULL;
  size_t step = 32;
  size_t used = 0;
  char* ptr = NULL;
  size_t len = 0;
 
  if (!plineptr || !psize)
  {
    errno = EINVAL;
    return -1;
  }
 
  do
  {
    if (used + 2 >= len)
    {
      len += step;
      n = realloc(ptr, len);
 
      if (!n)
      {
        return -1;
      }
 
      ptr = n;
    }
 
    c = freerdp_interruptible_getc(context, stream);
    if (c != EOF)
      ptr[used++] = (char)c;
  } while ((c != '\n') && (c != '\r') && (c != EOF));
 
  ptr[used] = '\0';
  if (c == EOF)
  {
    free(ptr);
    return EOF;
  }
  *plineptr = ptr;
  *psize = used;
  return WINPR_ASSERTING_INT_CAST(SSIZE_T, used);
}