diff options
| -rw-r--r-- | include/libbb.h | 1 | ||||
| -rw-r--r-- | libbb/Kbuild.src | 1 | ||||
| -rw-r--r-- | libbb/correct_password.c | 96 | ||||
| -rw-r--r-- | networking/Config.src | 7 | ||||
| -rw-r--r-- | networking/ftpd.c | 47 |
5 files changed, 100 insertions, 52 deletions
diff --git a/include/libbb.h b/include/libbb.h index 858084b..ff223dd 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -1316,6 +1316,7 @@ int sd_listen_fds(void); #define SETUP_ENV_NO_CHDIR (1 << 4) void setup_environment(const char *shell, int flags, const struct passwd *pw) FAST_FUNC; void nuke_str(char *str) FAST_FUNC; +int check_password(const struct passwd *pw, const char *plaintext) FAST_FUNC; int ask_and_check_password_extended(const struct passwd *pw, int timeout, const char *prompt) FAST_FUNC; int ask_and_check_password(const struct passwd *pw) FAST_FUNC; /* Returns a malloced string */ diff --git a/libbb/Kbuild.src b/libbb/Kbuild.src index 62680bd..0a9e803 100644 --- a/libbb/Kbuild.src +++ b/libbb/Kbuild.src @@ -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 diff --git a/libbb/correct_password.c b/libbb/correct_password.c index acadf39..513c930 100644 --- a/libbb/correct_password.c +++ b/libbb/correct_password.c @@ -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; } diff --git a/networking/Config.src b/networking/Config.src index fbad7ec..e566469 100644 --- a/networking/Config.src +++ b/networking/Config.src @@ -134,6 +134,13 @@ config FEATURE_FTPD_ACCEPT_BROKEN_LIST it increases the code size by ~40 bytes. Most other ftp servers seem to behave similar to this. +config FEATURE_FTP_AUTHENTICATION + bool "Enable authentication" + default y + depends on FTPD + help + Enable basic system login as seen in telnet etc. + config FTPGET bool "ftpget" default y diff --git a/networking/ftpd.c b/networking/ftpd.c index 2d2a3a4..9fcc3e9 100644 --- a/networking/ftpd.c +++ b/networking/ftpd.c @@ -1172,18 +1172,6 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) if (logmode) applet_name = xasprintf("%s[%u]", applet_name, (int)getpid()); -#if !BB_MMU - G.root_fd = -1; -#endif - argv += optind; - if (argv[0]) { -#if !BB_MMU - G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY); - close_on_exec_on(G.root_fd); -#endif - xchroot(argv[0]); - } - //umask(077); - admin can set umask before starting us /* Signals. We'll always take -EPIPE rather than a rude signal, thanks */ @@ -1199,23 +1187,22 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) WRITE_OK(FTP_GREET); signal(SIGALRM, timeout_handler); -#ifdef IF_WE_WANT_TO_REQUIRE_LOGIN +#if ENABLE_FEATURE_FTP_AUTHENTICATION { - smallint user_was_specified = 0; + struct passwd *pw = NULL; + while (1) { uint32_t cmdval = cmdio_get_cmd_and_arg(); if (cmdval == const_USER) { - if (G.ftp_arg == NULL || strcasecmp(G.ftp_arg, "anonymous") != 0) - cmdio_write_raw(STR(FTP_LOGINERR)" Server is anonymous only\r\n"); - else { - user_was_specified = 1; - cmdio_write_raw(STR(FTP_GIVEPWORD)" Please specify the password\r\n"); - } + pw = getpwnam(G.ftp_arg); + cmdio_write_raw(STR(FTP_GIVEPWORD)" Please specify password\r\n"); } else if (cmdval == const_PASS) { - if (user_was_specified) - break; - cmdio_write_raw(STR(FTP_NEEDUSER)" Login with USER\r\n"); + if (check_password(pw, G.ftp_arg) > 0) { + break; /* login success */ + } + cmdio_write_raw(STR(FTP_LOGINERR)" Login failed\r\n"); + pw = NULL; } else if (cmdval == const_QUIT) { WRITE_OK(FTP_GOODBYE); return 0; @@ -1223,10 +1210,24 @@ int ftpd_main(int argc UNUSED_PARAM, char **argv) cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER and PASS\r\n"); } } + change_identity(pw); } WRITE_OK(FTP_LOGINOK); #endif + /* Do this after auth, else /etc/passwd is not accessible */ +#if !BB_MMU + G.root_fd = -1; +#endif + argv += optind; + if (argv[0]) { +#if !BB_MMU + G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY); + close_on_exec_on(G.root_fd); +#endif + xchroot(argv[0]); + } + /* RFC-959 Section 5.1 * The following commands and options MUST be supported by every * server-FTP and user-FTP, except in cases where the underlying |