1 files changed, 80 insertions, 0 deletions
diff --git a/libbb/correct_password.c b/libbb/correct_password.c
new file mode 100644
index 0000000..255b048
--- /dev/null
+++ b/libbb/correct_password.c
@@ -0,0 +1,80 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Julianne F. Haugh nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JULIE HAUGH AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL JULIE HAUGH OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "libbb.h"
+
+/* Ask the user for a password.
+ * Return 1 if the user gives the correct password for entry PW,
+ * 0 if not.  Return 1 without asking if PW has an empty password.
+ *
+ * NULL pw means "just fake it for login with bad username" */
+
+int FAST_FUNC correct_password(const struct passwd *pw)
+{
+	char *unencrypted, *encrypted;
+	const char *correct;
+	int r;
+#if ENABLE_FEATURE_SHADOWPASSWDS
+	/* Using _r function to avoid pulling in static buffers */
+	struct spwd spw;
+	char buffer[256];
+#endif
+
+	/* fake salt. crypt() can choke otherwise. */
+	correct = "aa";
+	if (!pw) {
+		/* "aa" will never match */
+		goto fake_it;
+	}
+	correct = pw->pw_passwd;
+#if ENABLE_FEATURE_SHADOWPASSWDS
+	if ((correct[0] == 'x' || correct[0] == '*') && !correct[1]) {
+		/* getspnam_r may return 0 yet set result to NULL.
+		 * At least glibc 2.4 does this. Be extra paranoid here. */
+		struct spwd *result = NULL;
+		r = getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result);
+		correct = (r || !result) ? "aa" : result->sp_pwdp;
+	}
+#endif
+
+	if (!correct[0]) /* empty password field? */
+		return 1;
+
+ fake_it:
+	unencrypted = bb_askpass(0, "Password: ");
+	if (!unencrypted) {
+		return 0;
+	}
+	encrypted = pw_encrypt(unencrypted, correct, 1);
+	r = (strcmp(encrypted, correct) == 0);
+	free(encrypted);
+	memset(unencrypted, 0, strlen(unencrypted));
+	return r;
+}