tRead passphrase interactively and derivate a key from it - safe - password protected secret keeper
(HTM) git clone git://git.z3bra.org/safe.git
(DIR) Log
(DIR) Files
(DIR) Refs
(DIR) README
(DIR) LICENSE
---
(DIR) commit bb6f5f8dfd93aea029e27e5c38964bbf05c649a2
(DIR) parent d003bd0061a5dbb5d92bc0e71c0e35f69fdfe04a
(HTM) Author: z3bra <contactatz3bradotorg>
Date: Tue, 21 May 2019 23:56:27 +0200
Read passphrase interactively and derivate a key from it
Diffstat:
M mkfile | 2 +-
A readpassphrase.c | 187 +++++++++++++++++++++++++++++++
A readpassphrase.h | 31 +++++++++++++++++++++++++++++++
M safe.c | 102 +++++++++++++++++++++++--------
4 files changed, 296 insertions(+), 26 deletions(-)
---
(DIR) diff --git a/mkfile b/mkfile
t@@ -10,7 +10,7 @@ LDFLAGS =
LDLIBS = -lsodium
BIN = safe
-SRC = ${BIN}.c
+SRC = ${BIN}.c readpassphrase.c
OBJ = ${SRC:%.c=%.o}
${BIN}: $OBJ
(DIR) diff --git a/readpassphrase.c b/readpassphrase.c
t@@ -0,0 +1,187 @@
+/* $OpenBSD: readpassphrase.c,v 1.25 2015/09/14 10:45:27 guenther Exp $ */
+
+/*
+ * Copyright (c) 2000-2002, 2007, 2010
+ * Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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 <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>
+
+#include "readpassphrase.h"
+
+#ifdef TCSASOFT
+#define _T_FLUSH (TCSAFLUSH|TCSASOFT)
+#else
+#define _T_FLUSH (TCSAFLUSH)
+#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, _T_FLUSH, &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) {
+ while (tcsetattr(input, _T_FLUSH, &oterm) == -1 &&
+ errno == EINTR && !signo[SIGTTOU])
+ continue;
+ }
+ (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);
+}
+
+static void handler(int s)
+{
+ signo[s] = 1;
+}
(DIR) diff --git a/readpassphrase.h b/readpassphrase.h
t@@ -0,0 +1,31 @@
+/* $OpenBSD: readpassphrase.h,v 1.5 2003/06/17 21:56:23 millert Exp $ */
+
+/*
+ * Copyright (c) 2000, 2002 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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.
+ */
+
+#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 *, char *, size_t, int);
(DIR) diff --git a/safe.c b/safe.c
t@@ -13,12 +13,27 @@
#include <sodium.h>
#include "arg.h"
+#include "readpassphrase.h"
#define MDSIZE crypto_generichash_BYTES
-#define SAFE ".safe.d"
+#define SAFE ".secrets"
+#define META ".meta"
+
+struct secret {
+ char hex[256];
+};
+
+struct safe {
+ uint8_t salt[crypto_pwhash_SALTBYTES];
+ struct secret *secrets;
+};
char *argv0;
+uint8_t key[crypto_secretstream_xchacha20poly1305_KEYBYTES];
+uint8_t *passphrase;
+uint32_t pplen;
+
void
str2bin(char *s, uint8_t *d, size_t size)
{
t@@ -80,10 +95,31 @@ xwrite(int fd, const void *buf, size_t nbytes)
void
usage(void)
{
- fprintf(stderr, "usage: %s [-h] [-s safe] [-p pass] [[-a] entry]\n", argv0);
+ fprintf(stderr, "usage: %s [-h] [-s safe] [[-a] entry]\n", argv0);
exit(1);
}
+static int
+readpass(const char *prompt, uint8_t **target, uint32_t *len)
+{
+ char pass[BUFSIZ], *p;
+
+ p = readpassphrase(prompt, pass, sizeof(pass), RPP_ECHO_OFF);
+ if (!p)
+ err(1, "readpassphrase:");
+
+ if (p[0] == '\0')
+ return -1;
+
+ *target = realloc(*target, strlen(p)); /* not null-terminated */
+ if (!*target)
+ err(1, "realloc:");
+
+ memcpy(*target, p, strlen(p));
+ *len = strlen(p);
+ return 0;
+}
+
void
hash(uint8_t *buf, size_t size, uint8_t *md, size_t mdsize)
{
t@@ -91,21 +127,17 @@ hash(uint8_t *buf, size_t size, uint8_t *md, size_t mdsize)
}
void
-hash_key(char *pass)
+deriv(char *pw, struct safe *s)
{
- size_t i;
- uint8_t md[MDSIZE];
- char key[MDSIZE * 2];
-
- hash((uint8_t *)pass, strlen(pass), md, sizeof(md));
- bin2str(md, key, MDSIZE);
-
- for (i = 0; i < sizeof(key); i++)
- key[i] &= 1;
+ if (crypto_pwhash(key, sizeof(key), pw, strlen(pw),
+ s->salt, crypto_pwhash_OPSLIMIT_INTERACTIVE,
+ crypto_pwhash_MEMLIMIT_INTERACTIVE,
+ crypto_pwhash_ALG_DEFAULT))
+ err(1, "crypto_pwhash");
}
int
-store_secret(int fd, char *name)
+store_secret(struct safe *s, int fd, char *name)
{
int sfd;
ssize_t n;
t@@ -128,7 +160,7 @@ store_secret(int fd, char *name)
}
int
-show_secret(int fd, char *name)
+show_secret(struct safe *s, int fd, char *name)
{
int sfd;
ssize_t n;
t@@ -151,19 +183,41 @@ show_secret(int fd, char *name)
return 0;
}
+void
+init(struct safe *s)
+{
+ struct stat sb;
+ if (sodium_init() < 0)
+ err(1, "sodium: failed to initialize library");
+
+ if (stat(META, &sb)) {
+ randombytes_buf(s->salt, sizeof(s->salt));
+ s->secrets = NULL;
+ }
+}
+
+void
+deinit(struct safe *s)
+{
+ int fd;
+
+ fd = open(META, O_RDWR | O_CREAT | O_EXCL, 0600);
+ write(fd, s, sizeof(*s));
+ fsync(fd);
+ close(fd);
+}
+
int
main(int argc, char *argv[])
{
int aflag = 0;
- char *secret = NULL, *pass = NULL, *safe = SAFE;
+ char *secret = NULL, *safe = SAFE;
+ struct safe s;
ARGBEGIN {
case 'a':
aflag = 1;
break;
- case 'p':
- pass = EARGF(usage());
- break;
case 's':
safe = EARGF(usage());
break;
t@@ -174,25 +228,23 @@ main(int argc, char *argv[])
if (argc != 1)
usage();
-
if (safe) {
mkdir(safe, 0700);
if (chdir(safe) < 0)
err(1, "chdir: %s", safe);
}
- if (sodium_init() < 0)
- err(1, "sodium: failed to initialize library");
+ init(&s);
- if (pass)
- hash_key(pass);
+ readpass("Passphrase:", &passphrase, &pplen);
+ deriv((char *)passphrase, &s);
secret = argv[0];
if (aflag) {
- store_secret(STDIN_FILENO, secret);
+ store_secret(&s, STDIN_FILENO, secret);
} else {
- show_secret(STDOUT_FILENO, secret);
+ show_secret(&s, STDOUT_FILENO, secret);
}
return 0;