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shadow.cpp File Reference

#include "shadow.h"
#include <string.h>
#include <pwd.h>
#include <crypt.h>
#include <malloc.h>
#include <stdio.h>

Go to the source code of this file.

Functions
bool	AuthenticateShadow (packet* pak, Buffer *in)
	Authenticate using shadow password. More...
bool	CheckShadowed ( char *name, char *password )
	Looks up the username and password in the /etc/shadow file. More...

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Function Documentation

bool AuthenticateShadow ( packet * pak, Buffer * in)

Authenticate using shadow password.

Parameters:

pak	the authentication packet
in	the buffer where the answer has to be sent

Returns:

true on success, false on failure

Definition at line 22 of file shadow.cpp.

{
    char name[100], password[100];
    struct passwd *passwrd;

    if ((pak->h.header[0] != PROT_AUTHENTICATE) || (pak->h.header[1] != AUTH_PASSWORD)) {
    return false;
    }

    if (((int) strlen(pak->data.c_str ())) != (pak->h.header[2] + pak->h.header[3])) {
        return false;
    }

    /*this splits the clientPacket-data, which includes the name and the password
    into two variables. */
    memcpy ( &name, pak->data.c_str (), pak->h.header[2] );
    memcpy ( &password, pak->data.c_str () + pak->h.header[2], pak->h.header[3] );

    name[pak->h.header[2]] = '\0';
    password[pak->h.header[3]] = '\0';

    passwrd = getpwnam ( name ); /* returns NULL when the name does not exist. */

    if (!passwrd) /* name does not exist */
        {
        return false;
        }

    if (strcmp (passwrd->pw_name, "x") == 0)  // non-shadowed systems not supported
        {
        return false;
        }

    if (CheckShadowed (name, password))
        {
        packet* temp = new ( packet );

        temp->h.header[0] = PROT_REGISTER_ENTITY;
        temp->data = name;

        in->write(temp);

        return true;
        }

    return false;
    }

bool CheckShadowed ( char * name, char * password)

Looks up the username and password in the /etc/shadow file.

Parameters:

name	the username
password	the password (plain-text)

Returns:

true on success, false on failure

Definition at line 69 of file shadow.cpp.

{
    struct spwd *shadow;
    char *salt;

    salt = (char *) malloc ( 2 );

    setspent ();    /*this is necessary to be read in a clean way */

    shadow = getspnam ( name );

    if(shadow==NULL) { /* we have a failure then */
    return false;
    };

    endspent ();

    salt[0] = shadow->sp_pwdp[0];
    salt[1] = shadow->sp_pwdp[1];

    if ( strcmp ( shadow->sp_pwdp, crypt ( password, salt ) ) == 0 )
        {
        return true;
        }

    return false;
    }

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