ftpd: add optional support for authentication

function                                             old     new   delta
cmdio_get_cmd_and_arg                                  -     237    +237
get_passwd                                             -      97     +97
check_password                                         -      82     +82
ftpd_main                                           2297    2178    -119
ask_and_check_password_extended                      206      84    -122
------------------------------------------------------------------------------
(add/remove: 3/0 grow/shrink: 0/2 up/down: 416/-241)          Total: 175 bytes

Signed-off-by: Morten Kvistgaard <MK@pch-engineering.dk>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Morten Kvistgaard
2014-08-05 21:57:18 +02:00
committed by Denys Vlasenko
parent 09a0e2223f
commit feac9b607d
5 changed files with 100 additions and 52 deletions

View File

@ -150,6 +150,7 @@ lib-$(CONFIG_VLOCK) += pw_encrypt.o correct_password.o
lib-$(CONFIG_SU) += pw_encrypt.o correct_password.o
lib-$(CONFIG_LOGIN) += pw_encrypt.o correct_password.o
lib-$(CONFIG_FEATURE_HTTPD_AUTH_MD5) += pw_encrypt.o
lib-$(CONFIG_FEATURE_FTP_AUTHENTICATION) += pw_encrypt.o
lib-$(CONFIG_DF) += find_mount_point.o
lib-$(CONFIG_MKFS_MINIX) += find_mount_point.o

View File

@ -30,6 +30,63 @@
#include "libbb.h"
#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])
{
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 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;
}
/* 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.
@ -41,42 +98,23 @@
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? */
pw_pass = get_passwd(pw, buffer);
if (!pw_pass[0]) /* empty password field? */
return 1;
fake_it:
unencrypted = bb_ask(STDIN_FILENO, timeout, prompt);
if (!unencrypted) {
plaintext = bb_ask(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;
}