p11-kit: Support PIN prompting from tty

This adds support for prompting PIN on the terminal, through the
readpassphrase function borrowed from libbsd.

Signed-off-by: Daiki Ueno <[email protected]>

common/Makefile.am

@@ -55,6 +55,12 @@ if !OS_WIN32
 libp11_tool_la_SOURCES += \
 	common/unix-peer.c common/unix-peer.h \
 	$(NULL)
+
+if NEED_READPASSPHRASE
+libp11_tool_la_SOURCES += \
+	common/readpassphrase.c \
+	$(NULL)
+endif
 endif
 
 # Tests ----------------------------------------------------------------

common/compat.h

@@ -381,6 +381,23 @@ int        isatty           (int fd);
 
 #endif /* HAVE_ISATTY */
 
+#ifndef HAVE_READPASSPHRASE
+
+#define RPP_ECHO_OFF    0x00		/* Turn off echo (default). */
+#define RPP_ECHO_ON     0x01		/* Leave echo on. */
+#define RPP_REQUIRE_TTY 0x02		/* Fail if there is no tty. */
+#define RPP_FORCELOWER  0x04		/* Force input to lower case. */
+#define RPP_FORCEUPPER  0x08		/* Force input to upper case. */
+#define RPP_SEVENBIT    0x10		/* Strip the high bit from input. */
+#define RPP_STDIN       0x20		/* Read from stdin, not /dev/tty */
+
+char      *readpassphrase   (const char *prompt,
+                             char *buf,
+                             size_t bufsiz,
+                             int flags);
+
+#endif /* HAVE_ISATTY */
+
 /* If either locale_t or newlocale() is not available, strerror_l()
  * cannot be used */
 #if !defined(HAVE_LOCALE_T) || !defined(HAVE_NEWLOCALE)

common/meson.build

@@ -21,6 +21,16 @@ libp11_common_sources = [
   'vsock.c'
 ]
 
+rpl_functions = [
+  'readpassphrase',
+]
+
+foreach f : rpl_functions
+  if not cc.has_function(f)
+    libp11_common_sources += '@[email protected]'.format(f)
+  endif
+endforeach
+
 libp11_common = static_library('p11-common', libp11_common_sources,
                                gnu_symbol_visibility: 'hidden',
                                include_directories: configinc)

common/readpassphrase.c

@@ -0,0 +1,208 @@
+/*	$OpenBSD: readpassphrase.c,v 1.26 2016/10/18 12:47:18 millert Exp $	*/
+
+/*
+ * Copyright (c) 2000-2002, 2007, 2010
+ *	Todd C. Miller <[email protected]>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+#include "compat.h"
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <paths.h>
+#include <pwd.h>
+#include <signal.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#ifndef TCSASOFT
+#define TCSASOFT 0
+#endif
+
+#ifndef _NSIG
+#if defined(NSIG)
+#define _NSIG NSIG
+#else
+/* The SIGRTMAX define might be set to a function such as sysconf(). */
+#define _NSIG (SIGRTMAX + 1)
+#endif
+#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;
+	/*
+	 * 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;
+	(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))
+		(void)write(output, prompt, strlen(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))
+		(void)write(output, "\n", 1);
+
+	/* 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;
+}

configure.ac

@@ -145,6 +145,8 @@ if test "$os_unix" = "yes"; then
 	AC_CHECK_FUNCS([getpeerucred])
 	AC_CHECK_FUNCS([issetugid])
 	AC_CHECK_FUNCS([isatty])
+	AC_CHECK_FUNCS([readpassphrase])
+	AM_CONDITIONAL([NEED_READPASSPHRASE], [test "$ac_cv_func_readpassphrase" != "yes"])
 
 	AC_CHECK_FUNC(
 		[strerror_r],

meson.build

@@ -197,6 +197,7 @@ if host_system != 'windows'
     'issetugid',
     'mkdtemp',
     'mkstemp',
+    'readpassphrase',
     'secure_getenv',
     'strndup'
   ]

p11-kit/Makefile.am

@@ -275,6 +275,10 @@ p11_kit_p11_kit_SOURCES = \
 	p11-kit/print-config.c \
 	$(NULL)
 
+if !OS_WIN32
+p11_kit_p11_kit_SOURCES += p11-kit/tty.c
+endif
+
 p11_kit_p11_kit_CFLAGS = $(COMMON_CFLAGS)
 p11_kit_p11_kit_LDADD =
 
@@ -296,20 +300,7 @@ bashcomp_DATA += bash-completion/p11-kit
 endif
 
 check_PROGRAMS += p11-kit/p11-kit-testable
-p11_kit_p11_kit_testable_SOURCES = \
-	p11-kit/add-profile.c \
-	p11-kit/delete-object.c \
-	p11-kit/delete-profile.c \
-	p11-kit/export-object.c \
-	p11-kit/generate-keypair.c \
-	p11-kit/list-objects.c \
-	p11-kit/list-profiles.c \
-	p11-kit/list-mechanisms.c \
-	p11-kit/list-tokens.c \
-	p11-kit/lists.c \
-	p11-kit/p11-kit.c \
-	p11-kit/print-config.c \
-	$(NULL)
+p11_kit_p11_kit_testable_SOURCES = $(p11_kit_p11_kit_SOURCES)
 
 p11_kit_p11_kit_testable_CFLAGS =
 p11_kit_p11_kit_testable_LDADD =

p11-kit/meson.build

@@ -224,6 +224,10 @@ p11_kit_sources = [
   'print-config.c'
 ]
 
+if host_system != 'windows'
+  p11_kit_sources += 'tty.c'
+endif
+
 executable('p11-kit',
            p11_kit_sources,
            c_args: common_c_args + libp11_kit_internal_c_args,