diff -u -r ../dropbear-2019.77/svr-authpasswd.c ./svr-authpasswd.c --- ../dropbear-2019.77/svr-authpasswd.c 2019-03-23 13:46:29.000000000 +0000 +++ ./svr-authpasswd.c 2019-03-24 22:40:59.586161245 +0000 @@ -33,28 +33,13 @@ #if DROPBEAR_SVR_PASSWORD_AUTH -/* not constant time when strings are differing lengths. - string content isn't leaked, and crypt hashes are predictable length. */ -static int constant_time_strcmp(const char* a, const char* b) { - size_t la = strlen(a); - size_t lb = strlen(b); - - if (la != lb) { - return 1; - } - - return constant_time_memcmp(a, b, la); -} +#include /* Process a password auth request, sending success or failure messages as * appropriate */ 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 = NULL; - unsigned int passwordlen; - unsigned int changepw; + char *password; + unsigned int changepw, passwordlen; /* check if client wants to change password */ changepw = buf_getbool(ses.payload); @@ -65,47 +50,14 @@ } password = buf_getstring(ses.payload, &passwordlen); - 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", - ses.authstate.pw_name); - send_msg_userauth_failure(0, 1); - return; - } - - /* check for empty password */ - if (passwdcrypt[0] == '\0') { - dropbear_log(LOG_WARNING, "User '%s' has blank password, rejected", - ses.authstate.pw_name); - send_msg_userauth_failure(0, 1); - return; - } - if (constant_time_strcmp(testcrypt, passwdcrypt) == 0) { + /* check if password is valid */ + if (termux_auth(ses.authstate.pw_name, password)) { + if (!ses.authstate.pw_name) { + dropbear_log(LOG_WARNING, "Login name is NULL"); + send_msg_userauth_failure(0, 1); + return; + } /* successful authentication */ dropbear_log(LOG_NOTICE, "Password auth succeeded for '%s' from %s",