#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" */
+#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;
- const char *correct;
+ const char *pass;
- /* fake salt. crypt() can choke otherwise. */
- correct = "aa";
- if (!pw) {
- /* "aa" will never match */
- goto fake_it;
- }
- correct = pw->pw_passwd;
+ if (!pw)
+ return "aa"; /* "aa" will never match */
+
+ pass = pw->pw_passwd;
#if ENABLE_FEATURE_SHADOWPASSWDS
- if ((correct[0] == 'x' || correct[0] == '*') && !correct[1]) {
- /* Using _r function to avoid pulling in static buffers */
+ /* Using _r function to avoid pulling in static buffers */
+ if ((pass[0] == 'x' || pass[0] == '*') && !pass[1]) {
struct spwd spw;
- struct spwd *result;
- char buffer[256];
- if (getspnam_r(pw->pw_name, &spw, buffer, sizeof(buffer), &result) == 0)
- correct = spw.sp_pwdp;
- /* else: no valid shadow password, checking ordinary one */
+ 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;
+}
- 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;
+ }
- fake_it:
- unencrypted = bb_askpass(0, "Password: ");
- if (!unencrypted) {
- return 0;
+ 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 -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) == 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: ");
}