Add optional libpwquality support for new LUKS passwords.

If password is entered through terminal (no keyfile specified)
and cryptsetup is compiled with --enable-pwquality, default
system pwquality settings are used to check password quality.

src/utils_password.c

@@ -0,0 +1,90 @@
+/*
+ * Password quality check wrapper
+ *
+ * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2012, Milan Broz
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "cryptsetup.h"
+
+int opt_force_password = 0;
+
+#if ENABLE_PWQUALITY
+#include <pwquality.h>
+
+static int tools_check_pwquality(const char *password)
+{
+	int r;
+	void *auxerror;
+	pwquality_settings_t *pwq; 
+
+	log_dbg("Checking new password using default pwquality settings.");
+	pwq = pwquality_default_settings();
+	if (!pwq)
+		return -EINVAL;
+
+	r = pwquality_read_config(pwq, NULL, &auxerror);
+	if (r) {
+		log_err(_("Cannot check passsword quality: %s\n"),
+			pwquality_strerror(NULL, 0, r, auxerror));
+		pwquality_free_settings(pwq);
+		return -EINVAL;
+	}
+
+	r = pwquality_check(pwq, password, NULL, NULL, &auxerror);
+	if (r < 0) {
+		log_err(_("Password quality check failed:\n %s\n"),
+			pwquality_strerror(NULL, 0, r, auxerror));
+		r = -EPERM;
+	} else {
+		log_dbg("New password libpwquality score is %d.", r);
+		r = 0;
+	}
+
+	pwquality_free_settings(pwq);
+	return r;
+}
+#else /* ENABLE_PWQUALITY */
+static int tools_check_pwquality(const char *password)
+{
+	return 0;
+}
+#endif /* ENABLE_PWQUALITY */
+
+int tools_get_key(const char *prompt,
+		  char **key, size_t *key_size,
+		  size_t keyfile_offset, size_t keyfile_size_max,
+		  const char *key_file,
+		  int timeout, int verify, int pwquality,
+		  struct crypt_device *cd)
+{
+	int r, block;
+
+	block = tools_signals_blocked();
+	if (block)
+		set_int_block(0);
+
+	r = crypt_get_key(prompt, key, key_size, keyfile_offset,
+			  keyfile_size_max, key_file, timeout, verify, cd);
+	if (block && !quit)
+		set_int_block(1);
+
+	/* Check pwquality for password (not keyfile) */
+	if (pwquality && !opt_force_password && !key_file && !r)
+		r = tools_check_pwquality(*key);
+
+	return r;
+}