diff options
Diffstat (limited to 'svr-authpasswd.c')
| -rw-r--r-- | svr-authpasswd.c | 36 |
1 files changed, 23 insertions, 13 deletions
diff --git a/svr-authpasswd.c b/svr-authpasswd.c index bdee2aa..a4f3202 100644 --- a/svr-authpasswd.c +++ b/svr-authpasswd.c @@ -48,22 +48,14 @@ static int constant_time_strcmp(const char* a, const char* b) { /* Process a password auth request, sending success or failure messages as * appropriate */ -void svr_auth_password() { +void svr_auth_password(int valid_user) { char * passwdcrypt = NULL; /* the crypt from /etc/passwd or /etc/shadow */ char * testcrypt = NULL; /* crypt generated from the user's password sent */ - char * password; + char * password = NULL; unsigned int passwordlen; - unsigned int changepw; - passwdcrypt = ses.authstate.pw_passwd; - -#ifdef DEBUG_HACKCRYPT - /* debugging crypt for non-root testing with shadows */ - passwdcrypt = DEBUG_HACKCRYPT; -#endif - /* check if client wants to change password */ changepw = buf_getbool(ses.payload); if (changepw) { @@ -73,12 +65,30 @@ void svr_auth_password() { } password = buf_getstring(ses.payload, &passwordlen); - - /* the first bytes of passwdcrypt are the salt */ - testcrypt = crypt(password, passwdcrypt); + if (valid_user && passwordlen <= DROPBEAR_MAX_PASSWORD_LEN) { + /* the first bytes of passwdcrypt are the salt */ + passwdcrypt = ses.authstate.pw_passwd; + testcrypt = crypt(password, passwdcrypt); + } m_burn(password, passwordlen); m_free(password); + /* After we have got the payload contents we can exit if the username + is invalid. Invalid users have already been logged. */ + if (!valid_user) { + send_msg_userauth_failure(0, 1); + return; + } + + if (passwordlen > DROPBEAR_MAX_PASSWORD_LEN) { + dropbear_log(LOG_WARNING, + "Too-long password attempt for '%s' from %s", + ses.authstate.pw_name, + svr_ses.addrstring); + send_msg_userauth_failure(0, 1); + return; + } + if (testcrypt == NULL) { /* crypt() with an invalid salt like "!!" */ dropbear_log(LOG_WARNING, "User account '%s' is locked", |