mirror of
http://galexander.org/git/simplesshd.git
synced 2024-11-16 03:59:03 +00:00
113 lines
3.3 KiB
C
113 lines
3.3 KiB
C
/*
|
|
* Dropbear - a SSH2 server
|
|
*
|
|
* Copyright (c) 2002,2003 Matt Johnston
|
|
* All rights reserved.
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
* SOFTWARE. */
|
|
|
|
/* Validates a user password */
|
|
|
|
#include "includes.h"
|
|
#include "session.h"
|
|
#include "buffer.h"
|
|
#include "dbutil.h"
|
|
#include "auth.h"
|
|
#include "runopts.h"
|
|
|
|
#ifdef ENABLE_SVR_PASSWORD_AUTH
|
|
|
|
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);
|
|
}
|
|
|
|
/* Process a password auth request, sending success or failure messages as
|
|
* appropriate */
|
|
void svr_auth_password() {
|
|
|
|
char * passwdcrypt = NULL; /* the crypt from /etc/passwd or /etc/shadow */
|
|
char * testcrypt = NULL; /* crypt generated from the user's password sent */
|
|
unsigned char * password;
|
|
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) {
|
|
/* not implemented by this server */
|
|
send_msg_userauth_failure(0, 1);
|
|
return;
|
|
}
|
|
|
|
password = buf_getstring(ses.payload, &passwordlen);
|
|
|
|
/* the first bytes of passwdcrypt are the salt */
|
|
testcrypt = crypt((char*)password, passwdcrypt);
|
|
m_burn(password, passwordlen);
|
|
m_free(password);
|
|
|
|
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) {
|
|
/* successful authentication */
|
|
dropbear_log(LOG_NOTICE,
|
|
"Password auth succeeded for '%s' from %s",
|
|
ses.authstate.pw_name,
|
|
svr_ses.addrstring);
|
|
send_msg_userauth_success();
|
|
} else {
|
|
dropbear_log(LOG_WARNING,
|
|
"Bad password attempt for '%s' from %s",
|
|
ses.authstate.pw_name,
|
|
svr_ses.addrstring);
|
|
send_msg_userauth_failure(0, 1);
|
|
}
|
|
}
|
|
|
|
#endif
|