ash: builtin: Mark more regular built-ins

[oweals/busybox.git] / libbb / correct_password.c

diff --git a/libbb/correct_password.c b/libbb/correct_password.c
index 5727c65fbd7824af37e03d9c2ca4733b3b54ae1f..cbe6cb38706828aeb7ffb723915c35dbd76c3eaf 100644 (file)
--- a/libbb/correct_password.c
+++ b/libbb/correct_password.c
@@ -15,7 +15,7 @@
  *    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
+ * 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
@@ -27,20 +27,67 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
-
 #include "libbb.h"
 
-void FAST_FUNC nuke_str(char *str)
+#define SHADOW_BUFSIZE 256
+
+/* 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])
 {
-        if (str) {
-               while (*str)
-                       *str++ = 0;
-               /* or: memset(str, 0, strlen(str)); - not as small as above */
+       const char *pass;
+
+       if (!pw)
+               return "aa"; /* "aa" will never match */
+
+       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
+       return pass;
 }
 
+/*
+ * Return CHECKPASS_PW_HAS_EMPTY_PASSWORD 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 CHECKPASS_PW_HAS_EMPTY_PASSWORD;
+       }
+
+       encrypted = pw_encrypt(plaintext, /*salt:*/ pw_pass, 1);
+       r = (strcmp(encrypted, pw_pass) == 0);
+       free(encrypted);
+       return r;
+}
+
+
 /* Ask the user for a password.
- * Return 1 without asking if PW has an empty password.
+ * Return CHECKPASS_PW_HAS_EMPTY_PASSWORD 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.
@@ -50,42 +97,23 @@ void FAST_FUNC nuke_str(char *str)
 int FAST_FUNC ask_and_check_password_extended(const struct passwd *pw,
                int timeout, const char *prompt)
 {
-       char *unencrypted, *encrypted;
-       const char *correct;
+       IF_FEATURE_SHADOWPASSWDS(char buffer[SHADOW_BUFSIZE];)
+       char *plaintext;
+       const char *pw_pass;
        int r;
-       /* 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
-       /* Using _r function to avoid pulling in static buffers */
-       if ((correct[0] == 'x' || correct[0] == '*') && !correct[1]) {
-               struct spwd spw;
-               char buffer[256];
-               /* 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;
+       pw_pass = get_passwd(pw, buffer);
+       if (!pw_pass[0]) /* empty password field? */
+               return CHECKPASS_PW_HAS_EMPTY_PASSWORD;
 
- fake_it:
-       unencrypted = bb_ask(STDIN_FILENO, timeout, prompt);
-       if (!unencrypted) {
+       plaintext = bb_ask_noecho(STDIN_FILENO, timeout, prompt);
+       if (!plaintext) {
                /* EOF (such as ^D) or error (such as ^C) or timeout */
                return -1;
        }
-       encrypted = pw_encrypt(unencrypted, correct, 1);
-       r = (strcmp(encrypted, correct) == 0);
-       free(encrypted);
-       nuke_str(unencrypted);
+
+       r = check_password(pw, plaintext);
+       nuke_str(plaintext);
        return r;
 }