hsm_encryption: read from STDIN if not in a TTY

Changelog-Added: hsmtool: allow piped passwords

common/hsm_encryption.c

@@ -2,6 +2,8 @@
 #include <common/hsm_encryption.h>
 #include <sodium/utils.h>
 #include <termios.h>
+#include <unistd.h>
+#include <stdio.h>	
 
 char *hsm_secret_encryption_key(const char *pass, struct secret *key)
 {
@@ -84,31 +86,41 @@ char *read_stdin_pass(char **reason)
 	char *passwd = NULL;
 	size_t passwd_size = 0;
 
-	/* Set a temporary term, same as current but with ECHO disabled. */
-	if (tcgetattr(fileno(stdin), &current_term) != 0) {
-		*reason = "Could not get current terminal options.";
-		return NULL;
-	}
-	temp_term = current_term;
-	temp_term.c_lflag &= ~ECHO;
-	if (tcsetattr(fileno(stdin), TCSAFLUSH, &temp_term) != 0) {
-		*reason = "Could not disable pass echoing.";
-		return NULL;
-	}
-
-	/* Read the password, do not take the newline character into account. */
-	if (getline(&passwd, &passwd_size, stdin) < 0) {
-		*reason = "Could not read pass from stdin.";
-		return NULL;
-	}
-	if (passwd[strlen(passwd) - 1] == '\n')
-		passwd[strlen(passwd) - 1] = '\0';
-
-	/* Restore the original terminal */
-	if (tcsetattr(fileno(stdin), TCSAFLUSH, &current_term) != 0) {
-		*reason = "Could not restore terminal options.";
-		free(passwd);
-		return NULL;
+	if (isatty(fileno(stdin))) {
+		/* Set a temporary term, same as current but with ECHO disabled. */
+		if (tcgetattr(fileno(stdin), &current_term) != 0) {
+			*reason = "Could not get current terminal options.";
+			return NULL;
+		}
+		temp_term = current_term;
+		temp_term.c_lflag &= ~ECHO;
+		if (tcsetattr(fileno(stdin), TCSAFLUSH, &temp_term) != 0) {
+			*reason = "Could not disable pass echoing.";
+			return NULL;
+		}
+
+		/* Read the password, do not take the newline character into account. */
+		if (getline(&passwd, &passwd_size, stdin) < 0) {
+			*reason = "Could not read pass from stdin.";
+			return NULL;
+		}
+		if (passwd[strlen(passwd) - 1] == '\n')
+			passwd[strlen(passwd) - 1] = '\0';
+
+		/* Restore the original terminal */
+		if (tcsetattr(fileno(stdin), TCSAFLUSH, &current_term) != 0) {
+			*reason = "Could not restore terminal options.";
+			free(passwd);
+			return NULL;
+		}
+	} else {
+		/* Read from stdin, do not take the newline character into account. */
+		if (getline(&passwd, &passwd_size, stdin) < 0) {
+			*reason = "Could not read pass from stdin.";
+			return NULL;
+		}
+		if (passwd[strlen(passwd) - 1] == '\n')
+			passwd[strlen(passwd) - 1] = '\0';
 	}
 
 	return passwd;