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yap-6.3/packages/clib/crypt.c
Vítor Santos Costa 40febfdf9b clib package
2010-06-17 00:40:25 +01:00

166 lines
4.0 KiB
C

/* $Id$
Part of SWI-Prolog
Author: Jan Wielemaker
E-mail: J.Wielemaker@cs.vu.nl
WWW: http://www.swi-prolog.org
Copyright (C): 1985-2010, University of Amsterdam, VU Amsterdam
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef DEFINE_XOPEN_SOURCE
#define _XOPEN_SOURCE
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_CRYPT_H
#include <crypt.h>
#else
extern char *crypt(const char *key, const char *setting);
#endif
#include <stdlib.h>
#include <string.h>
#include <SWI-Stream.h>
#include <SWI-Prolog.h>
#include "clib.h"
/* md5passwd.c */
extern char *md5_crypt(const char *pw, const char *salt);
/* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Simple interface to the Unix password encryption routine. Implemented
for providing authorization in the multi-threaded Prolog based HTTP
deamon and therefore providing a thread-safe interface.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
#ifdef _REENTRANT
#include <pthread.h>
static pthread_mutex_t crypt_mutex = PTHREAD_MUTEX_INITIALIZER;
#define LOCK() pthread_mutex_lock(&crypt_mutex)
#define UNLOCK() pthread_mutex_unlock(&crypt_mutex)
#else
#define LOCK()
#define UNLOCK()
#endif
static foreign_t
pl_crypt(term_t passwd, term_t encrypted)
{ char *pw, *e;
char salt[20];
if ( !PL_get_chars(passwd, &pw, CVT_ATOM|CVT_STRING|CVT_LIST|BUF_RING) )
return pl_error("crypt", 2, NULL, ERR_ARGTYPE,
1, passwd, "text");
if ( PL_get_chars(encrypted, &e, CVT_ATOM|CVT_STRING|CVT_LIST|BUF_RING) )
{ char *s2;
if ( strncmp(e, "$1$", 3) == 0 ) /* MD5 Hash */
{ char *p = strchr(e+3, '$');
size_t slen;
if ( p && (slen=(size_t)(p-e-3)) < sizeof(salt) )
{ strncpy(salt, e+3, slen);
salt[slen] = 0;
s2 = md5_crypt(pw, salt);
return (strcmp(s2, e) == 0) ? TRUE : FALSE;
} else
{ Sdprintf("No salt???\n");
return FALSE;
}
} else
{ int rval;
salt[0] = e[0];
salt[1] = e[1];
salt[2] = '\0';
LOCK();
s2 = crypt(pw, salt);
rval = (strcmp(s2, e) == 0 ? TRUE : FALSE);
UNLOCK();
return rval;
}
} else
{ term_t tail = PL_copy_term_ref(encrypted);
term_t head = PL_new_term_ref();
int slen = 2;
int n;
int (*unify)(term_t t, const char *s) = PL_unify_list_codes;
char *s2;
int rval;
for(n=0; n<slen; n++)
{ if ( PL_get_list(tail, head, tail) )
{ int i;
char *t;
if ( PL_get_integer(head, &i) && i>=0 && i<=255 )
{ salt[n] = i;
} else if ( PL_get_atom_chars(head, &t) && t[1] == '\0' )
{ salt[n] = t[0];
unify = PL_unify_list_chars;
} else
{ return pl_error("crypt", 2, NULL, ERR_ARGTYPE,
2, head, "character");
}
if ( n == 1 && salt[0] == '$' && salt[1] == '1' )
slen = 3;
else if ( n == 2 && salt[2] == '$' )
slen = 8+3;
} else
break;
}
for( ; n < slen; n++ )
{ int c = 'a'+(int)(26.0*rand()/(RAND_MAX+1.0));
if ( rand() & 0x1 )
c += 'A' - 'a';
salt[n] = c;
}
salt[n] = 0;
LOCK();
if ( slen > 2 )
{ s2 = md5_crypt(pw, salt);
} else
{ s2 = crypt(pw, salt);
}
rval = (*unify)(encrypted, s2);
UNLOCK();
return rval;
}
}
install_t
install_crypt()
{ PL_register_foreign("crypt", 2, pl_crypt, 0);
}