cryptPasswd.c File Reference

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <sys/time.h>
#include <errno.h>
#include <unistd.h>
#include <getopt.h>

Go to the source code of this file.

Defines
#define	__USE_XOPEN
#define	FIRST_CHAR   '!'
#define	LAST_CHAR   '~'
#define	MAX_USER_NAME   256
#define	MAX_PASSWORD   8
#define	PASSWD_FILE_NAME   "RIOpasswd"
#define	ERROR_FILE_NOT_FOUND   1
#define	ERROR_PASSWORD_NOT_MATCH   2
#define	ERROR_NO_USERNAME   3
#define	ERROR_USER_ALREADY_EXISTS   4
#define	ERROR_STRING_TOO_LONG   5
Functions
void	Usage (char *program_name)
void	setSeed (void)
int	userFound (char *username)
int	createUser (char *username, char *password)
int	changeUserPasswd (char *username, char *password)
int	main (int argc, char **argv)
Variables
char	PASSWD_FILE [256]

---

Define Documentation

#define __USE_XOPEN

Definition at line 24 of file cryptPasswd.c.

#define ERROR_FILE_NOT_FOUND   1

Definition at line 35 of file cryptPasswd.c.

#define ERROR_NO_USERNAME   3

Definition at line 37 of file cryptPasswd.c.

#define ERROR_PASSWORD_NOT_MATCH   2

Definition at line 36 of file cryptPasswd.c.

#define ERROR_STRING_TOO_LONG   5

Definition at line 39 of file cryptPasswd.c.

#define ERROR_USER_ALREADY_EXISTS   4

Definition at line 38 of file cryptPasswd.c.

#define FIRST_CHAR   '!'

Definition at line 29 of file cryptPasswd.c.

#define LAST_CHAR   '~'

Definition at line 30 of file cryptPasswd.c.

#define MAX_PASSWORD   8

Definition at line 32 of file cryptPasswd.c.

#define MAX_USER_NAME   256

Definition at line 31 of file cryptPasswd.c.

#define PASSWD_FILE_NAME   "RIOpasswd"

Definition at line 33 of file cryptPasswd.c.

---

Function Documentation

int changeUserPasswd	(	char *	username,
		char *	password
	)

Definition at line 135 of file cryptPasswd.c.

{
    char currentUser[MAX_USER_NAME];
    char line[MAX_USER_NAME + MAX_PASSWORD + 1];
    FILE *passwd_file;
    int status = 0;

    passwd_file = fopen( PASSWD_FILE, "r+" );
    if( passwd_file != NULL )
    {
        while( !feof( passwd_file ) )
        {
            if( fgets( line, MAX_USER_NAME + MAX_PASSWORD + 1, 
                       passwd_file ) == NULL )
            {
                fprintf( stderr, "Error when reading %s passwd file\n", 
                         PASSWD_FILE );
            }
            sscanf( line, "%s", currentUser );

            if( strcmp( currentUser, username ) == 0 )
            {
                fseek( passwd_file, - strlen( line ), SEEK_CUR );
                fprintf( passwd_file, "%s %s\n", username, password );

                break;
             }
        }

        fclose( passwd_file );
    }
    else
    {
        fprintf( stderr, "Error opening passwd file!\n" );
        status = ERROR_FILE_NOT_FOUND;
    }

    return status;
}

int createUser	(	char *	username,
		char *	password
	)

Definition at line 112 of file cryptPasswd.c.

{
    int status = 0;
    FILE *passwd_file;

    passwd_file = fopen( PASSWD_FILE, "a" );
    if( passwd_file != NULL )
    {
        fprintf( passwd_file, "%s %s\n", username, password );
        fclose( passwd_file );
    }
    else
    {
        fprintf( stderr, "Error opening passwd file!\n" );
        status = ERROR_FILE_NOT_FOUND;
    }

    return status;
}

int main	(	int	argc,
		char **	argv
	)

Definition at line 175 of file cryptPasswd.c.

{
    char username[MAX_USER_NAME];
    char password[MAX_PASSWORD + 1], password_check[MAX_PASSWORD + 1];
    char *buffer;
    char overwrite;
    char salt[3];
    // Nova variavel para armazenar o diretorio onde o arquivo com senhas sera
    // armazenado.
    char *dirname = NULL;
    int status = 0;
    int ask_username = 0;
    int ask_password = 0;
    char optch;
    int ind = -1;
    // Mudanca para salvar o arquivo de senhas em qualquer diretorio alem 
    // daquele onde esta o programa.
    static char opts_short[] = "d:hp:u:v";
    static struct option opts_int[] =
    {
       // Mudanca para salvar o arquivo de senhas em qualquer diretorio alem
       // daquele onde esta o programa.
       {"directory"      ,1,0,'d'},
       {"help"           ,0,0,'h'},
       {"user"           ,1,0,'u'},
       {"password"       ,1,0,'p'},
       {"version"        ,0,0,'v'},
       {0,0,0,0}
    };

    while( ( optch = getopt_long( argc, argv, opts_short, opts_int, 
             &ind ) ) != -1 )
    {
        switch( optch )
        {
            case 'u':
                if( strlen( optarg ) <= MAX_USER_NAME )
                {
                    strcpy( username, optarg );
                    ask_username = 1;
                }
                else
                {
                    fprintf( stderr, "Username must be less than %d characters"
                                      " int\n", MAX_USER_NAME );
                    return( ERROR_STRING_TOO_LONG );
                }
                break;

            case 'p':
                if( strlen( optarg ) <= MAX_PASSWORD )
                {
                    strcpy( password, optarg );
                    ask_password = 1;
                }
                else
                {
                    fprintf( stderr, "Password must be less than %d characters"
                                      " int\n", MAX_PASSWORD );
                    return( ERROR_STRING_TOO_LONG );
                }
                
                break;

            case 'v':
                fprintf( stdout, "cryptPasswd version: %s\n", VERSION );
                return( 0 );

            case 'h':
            default:
                Usage( argv[ 0 ] );
                return( 0 );
            // Permite salvar as senhas em um diretorio generico.    
            case 'd':
                dirname = optarg;
                break;
        }
    }

    // Compoe o nome do arquivo de senhas.
    
    if( dirname == NULL)
        strcpy( PASSWD_FILE, PASSWD_FILE_NAME );
    else
    {
        strcpy( PASSWD_FILE, dirname );
        if( dirname[ strlen( dirname ) - 1 ] != '/')
            strcat( PASSWD_FILE, "/" );
        strcat( PASSWD_FILE, PASSWD_FILE_NAME );
    }
    
    // Verifica se o usuario pode acessar o arquivo
    if( ( access( PASSWD_FILE,  R_OK | W_OK ) != 0 ) && ( errno == EACCES ) )
    {
        fprintf( stderr, "Access to %s file denied!\n", PASSWD_FILE );
        exit( -1 );
    } 

    /* Get seed from system clock */
    setSeed();

    /* Get user name */
    if( ask_username == 0 )
    {
        fprintf( stdout, "Type user name or <Enter> to exit: " );
        if( fgets( username, MAX_USER_NAME , stdin ) == NULL )
        {
            fprintf( stderr, "Error when reading data from stdin\n" );
            exit( -1 );
        }
        username[ strlen( username ) - 1 ] = '\0';
    }

    /* User name entered */
    if( strlen( username ) != 0 )
    {
        /* User already exists */
        if( userFound( username ) )
        {
            fprintf( stdout, "User %s already exists. Overwrite? (y|n) ",
                             username );
            if( scanf( "%c", &overwrite ) != 1 ) 
            {
                fprintf( stderr, "Error when reading data from stdin\n" );
                exit( -1 );
            }
            if( overwrite == 'n' )
            {
                status = ERROR_USER_ALREADY_EXISTS;
            }
        }

        if( status == 0 )
        {
            /* Get user password */
            if( ask_password == 0 )
            {
                fprintf( stdout, "Type password for user '%s': ", username );
                buffer = getpass( "" );
                if( strlen( buffer ) > MAX_PASSWORD )
                {
                    fprintf( stderr, "Password must be less than %d characters"
                                      " int\n", MAX_PASSWORD + 1 );
                    return( ERROR_STRING_TOO_LONG );
                }

                strcpy( password, buffer );

                /* Get user password again for check */
                fprintf( stdout, "Retype user password: " );
                buffer = getpass( "" );
                if( strlen( buffer ) > MAX_PASSWORD )
                {
                    fprintf( stderr, "Password must be less than %d characters"
                                      " int\n", MAX_PASSWORD + 1 );
                    return( ERROR_STRING_TOO_LONG );
                }
                strcpy( password_check, buffer );
            }

            /* Password match */
            if( ( ask_password == 1 ) || 
                ( strcmp( password, password_check ) == 0 ) )
            {
                salt[0] = ( rand() % ( LAST_CHAR - FIRST_CHAR + 1 ) )
                                     + FIRST_CHAR;
                salt[1] = ( rand() % ( LAST_CHAR - FIRST_CHAR + 1 ) )
                                     + FIRST_CHAR;
                salt[2] = '\0';

                if( overwrite == 'y' )
                    status = changeUserPasswd( username,
                                               crypt( password, salt ) );
                else
                    status = createUser( username, crypt( password, salt ) );
                  
                if( status == 0 )   
                    fprintf( stdout, "Username and crypted password were "
                                     "written to file %s.\n", PASSWD_FILE );
            }
            /* Password doesn't match */
            else
            {
                if( overwrite == 'y' )
                {
                    fprintf( stderr, "Passwords do not match. "
                                     "Password for user %s not changed.\n",
                                     username );
                }
                else
                {
                    fprintf( stderr, "Passwords do not match. "
                                     "Password for user %s not created.\n",
                                     username );
                }
                status = ERROR_PASSWORD_NOT_MATCH;
            }
        }
    }
    else
    {
        status = ERROR_NO_USERNAME;
    }

    return status;
}

void setSeed

(

void

)

Definition at line 63 of file cryptPasswd.c.

{
    struct timeval time;
    unsigned int seed;

    gettimeofday(&time, NULL);
    seed = time.tv_sec * time.tv_usec;

    srand( seed );
}

void Usage

(

char *

program_name

)

Definition at line 46 of file cryptPasswd.c.

{
    fprintf( stdout, "\nUsage:\n" );
    fprintf( stdout, "    %s [ -d | directory] [ -h | --help | [-p | --password] <password> | [-u | --user] <username> | -v | --version |]\n", program_name );
    fprintf( stdout, "Where:\n" );
    fprintf( stdout, "    [-d | --directory]: directory to save passwd file\n" );
    fprintf( stdout, "    [-h | --help]: show this message\n" );
    fprintf( stdout, "    [-p | --password] <password>: use <password> as user's password\n" );
    fprintf( stdout, "    [-u | --user] <username>: use <username> as user's name\n" );
    fprintf( stdout, "    [-v | --version]: show version\n" );
    fprintf( stdout, "\n" );
}

int userFound

(

char *

username

)

Definition at line 77 of file cryptPasswd.c.

{
    char currentUser[MAX_USER_NAME];
    int status = 0;
    FILE *passwd_file;

    passwd_file = fopen( PASSWD_FILE, "r" );
    if( passwd_file != NULL )
    {
        while( !feof( passwd_file ) )
        {
            if( fscanf( passwd_file, "%s %*s\n", currentUser ) != 1 )
            {
                fprintf( stderr, "Error when reading %s passwd file\n", 
                         PASSWD_FILE );
                exit( -1 );                 
                         
            }

            if( strcmp( username, currentUser ) == 0 )
            {
                status = 1;
                break;
            }
        }

        fclose( passwd_file );
    }

    return status;
}

---

Variable Documentation

char PASSWD_FILE[256]

Definition at line 42 of file cryptPasswd.c.