+
+/* Read a passphrase ('Key') from /dev/tty with echo off.
+ * The caller (cmds.c) will call free on the string afterwards.
+ * Based on the code in cryptsetup file lib/utils.c.
+ */
+char *
+read_key (const char *param)
+{
+ FILE *infp, *outfp;
+ struct termios orig, temp;
+ char *ret = NULL;
+
+ /* Read and write to /dev/tty if available. */
+ if (keys_from_stdin ||
+ (infp = outfp = fopen ("/dev/tty", "w+")) == NULL) {
+ infp = stdin;
+ outfp = stdout;
+ }
+
+ /* Print the prompt and set no echo. */
+ int tty = isatty (fileno (infp));
+ int tcset = 0;
+ if (tty) {
+ fprintf (outfp, _("Enter key or passphrase (\"%s\"): "), param);
+
+ if (tcgetattr (fileno (infp), &orig) == -1) {
+ perror ("tcgetattr");
+ goto error;
+ }
+ memcpy (&temp, &orig, sizeof temp);
+ temp.c_lflag &= ~ECHO;
+
+ tcsetattr (fileno (infp), TCSAFLUSH, &temp);
+ tcset = 1;
+ }
+
+ size_t n = 0;
+ ssize_t len;
+ len = getline (&ret, &n, infp);
+ if (len == -1) {
+ perror ("getline");
+ ret = NULL;
+ goto error;
+ }
+
+ /* Remove the terminating \n if there is one. */
+ if (len > 0 && ret[len-1] == '\n')
+ ret[len-1] = '\0';
+
+ error:
+ /* Restore echo, close file descriptor. */
+ if (tty && tcset) {
+ printf ("\n");
+ tcsetattr (fileno (infp), TCSAFLUSH, &orig);
+ }
+
+ if (infp != stdin)
+ fclose (infp); /* outfp == infp, so this is closed also */
+
+ return ret;
+}