X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=libbb%2Fcorrect_password.c;h=513c930286feb89565a2895d40c7e2e9eaa18827;hb=5f7c82b32f548b5a1d6a4186630e8ef496a9d5e6;hp=d031b2109a6e9f8d8e655324f2f181255b409dfd;hpb=bf66fbc8e2380717c1fab860cfc60c78582839dd;p=oweals%2Fbusybox.git

diff --git a/libbb/correct_password.c b/libbb/correct_password.c
index d031b2109..513c93028 100644
--- a/libbb/correct_password.c
+++ b/libbb/correct_password.c
@@ -30,35 +30,95 @@
 
 #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 for a password if run by UID 0
-   or if PW has an empty password.  */
+#define SHADOW_BUFSIZE 256
 
-int correct_password(const struct passwd *pw)
+/* Retrieve encrypted password string for pw.
+ * If pw == NULL, return a string which fails password check against any
+ * password.
+ */
+#if !ENABLE_FEATURE_SHADOWPASSWDS
+#define get_passwd(pw, buffer) get_passwd(pw)
+#endif
+static const char *get_passwd(const struct passwd *pw, char buffer[SHADOW_BUFSIZE])
 {
-	char *unencrypted, *encrypted, *correct;
-
-#ifdef CONFIG_FEATURE_SHADOWPASSWDS
-	if (LONE_CHAR(pw->pw_passwd, 'x') || LONE_CHAR(pw->pw_passwd, '*')) {
-		struct spwd *sp = getspnam(pw->pw_name);
+	const char *pass;
 
-		if (!sp)
-			bb_error_msg_and_die("no valid shadow password");
+	if (!pw)
+		return "aa"; /* "aa" will never match */
 
-		correct = sp->sp_pwdp;
-	} else
+	pass = pw->pw_passwd;
+#if ENABLE_FEATURE_SHADOWPASSWDS
+	/* Using _r function to avoid pulling in static buffers */
+	if ((pass[0] == 'x' || pass[0] == '*') && !pass[1]) {
+		struct spwd spw;
+		int r;
+		/* 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, SHADOW_BUFSIZE, &result);
+		pass = (r || !result) ? "aa" : result->sp_pwdp;
+	}
 #endif
-		correct = pw->pw_passwd;
+	return pass;
+}
 
-	if (!correct || correct[0] == '\0')
+/*
+ * Return 1 if PW has an empty password.
+ * Return 1 if the user gives the correct password for entry PW,
+ * 0 if not.
+ * NULL pw means "just fake it for login with bad username"
+ */
+int FAST_FUNC check_password(const struct passwd *pw, const char *plaintext)
+{
+	IF_FEATURE_SHADOWPASSWDS(char buffer[SHADOW_BUFSIZE];)
+	char *encrypted;
+	const char *pw_pass;
+	int r;
+
+	pw_pass = get_passwd(pw, buffer);
+	if (!pw_pass[0]) { /* empty password field? */
 		return 1;
+	}
+
+	encrypted = pw_encrypt(plaintext, /*salt:*/ pw_pass, 1);
+	r = (strcmp(encrypted, pw_pass) == 0);
+	free(encrypted);
+	return r;
+}
 
-	unencrypted = bb_askpass(0, "Password: ");
-	if (!unencrypted) {
-		return 0;
+
+/* Ask the user for a password.
+ * Return 1 without asking if PW has an empty password.
+ * Return -1 on EOF, error while reading input, or timeout.
+ * Return 1 if the user gives the correct password for entry PW,
+ * 0 if not.
+ *
+ * NULL pw means "just fake it for login with bad username"
+ */
+int FAST_FUNC ask_and_check_password_extended(const struct passwd *pw,
+		int timeout, const char *prompt)
+{
+	IF_FEATURE_SHADOWPASSWDS(char buffer[SHADOW_BUFSIZE];)
+	char *plaintext;
+	const char *pw_pass;
+	int r;
+
+	pw_pass = get_passwd(pw, buffer);
+	if (!pw_pass[0]) /* empty password field? */
+		return 1;
+
+	plaintext = bb_ask(STDIN_FILENO, timeout, prompt);
+	if (!plaintext) {
+		/* EOF (such as ^D) or error (such as ^C) or timeout */
+		return -1;
 	}
-	encrypted = crypt(unencrypted, correct);
-	memset(unencrypted, 0, strlen(unencrypted));
-	return (!strcmp(encrypted, correct)) ? 1 : 0;
+
+	r = check_password(pw, plaintext);
+	nuke_str(plaintext);
+	return r;
+}
+
+int FAST_FUNC ask_and_check_password(const struct passwd *pw)
+{
+	return ask_and_check_password_extended(pw, 0, "Password: ");
 }