/*
* ----------------------------------------------------------------------------
* "THE BEER-WARE LICENSE" (Revision 42):
* <phk@login.dknet.dk> wrote this file. As long as you retain this notice you
* can do whatever you want with this stuff. If we meet some day, and you think
* this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
* ----------------------------------------------------------------------------
*
* $FreeBSD$
*
*/
#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = \
"$FreeBSD$";
#endif /* LIBC_SCCS and not lint */
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <md5.h>
#include <err.h>
#include "crypt.h"
#ifdef __PIC__
#include <dlfcn.h>
#define MD5Init(ctx) dl_MD5Init(ctx)
#define MD5Update(ctx, data, len) dl_MD5Update(ctx, data, len)
#define MD5Final(dgst, ctx) dl_MD5Final(dgst, ctx)
static void (*dl_MD5Init)(MD5_CTX *);
static void (*dl_MD5Update)(MD5_CTX *, const unsigned char *, unsigned int);
static void (*dl_MD5Final)(unsigned char digest[16], MD5_CTX *);
#endif
/*
* UNIX password
*/
char *
crypt_md5(pw, salt)
const char *pw;
const char *salt;
{
static char *magic = "$1$"; /*
* This string is magic for
* this algorithm. Having
* it this way, we can get
* get better later on
*/
static char passwd[120], *p;
static const char *sp,*ep;
unsigned char final[MD5_SIZE];
int sl,pl,i;
MD5_CTX ctx,ctx1;
unsigned long l;
#ifdef __PIC__
void *libmd;
#endif
/* Refine the Salt first */
sp = salt;
/* If it starts with the magic string, then skip that */
if(!strncmp(sp,magic,strlen(magic)))
sp += strlen(magic);
/* It stops at the first '$', max 8 chars */
for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++)
continue;
/* get the length of the true salt */
sl = ep - sp;
#ifdef __PIC__
libmd = dlopen("libmd.so", RTLD_NOW);
if (libmd == NULL) {
warnx("libcrypt-md5: dlopen(libmd.so): %s\n", dlerror());
return NULL;
}
dl_MD5Init = dlsym(libmd, "MD5Init");
if (dl_MD5Init == NULL) {
warnx("libcrypt-md5: looking for MD5Init: %s\n", dlerror());
dlclose(libmd);
return NULL;
}
dl_MD5Update = dlsym(libmd, "MD5Update");
if (dl_MD5Update == NULL) {
warnx("libcrypt-md5: looking for MD5Update: %s\n", dlerror());
dlclose(libmd);
return NULL;
}
dl_MD5Final = dlsym(libmd, "MD5Final");
if (dl_MD5Final == NULL) {
warnx("libcrypt-md5: looking for MD5Final: %s\n", dlerror());
dlclose(libmd);
return NULL;
}
#endif
MD5Init(&ctx);
/* The password first, since that is what is most unknown */
MD5Update(&ctx,pw,strlen(pw));
/* Then our magic string */
MD5Update(&ctx,magic,strlen(magic));
/* Then the raw salt */
MD5Update(&ctx,sp,sl);
/* Then just as many characters of the MD5(pw,salt,pw) */
MD5Init(&ctx1);
MD5Update(&ctx1,pw,strlen(pw));
MD5Update(&ctx1,sp,sl);
MD5Update(&ctx1,pw,strlen(pw));
MD5Final(final,&ctx1);
for(pl = strlen(pw); pl > 0; pl -= MD5_SIZE)
MD5Update(&ctx,final,pl>MD5_SIZE ? MD5_SIZE : pl);
/* Don't leave anything around in vm they could use. */
memset(final,0,sizeof final);
/* Then something really weird... */
for (i = strlen(pw); i ; i >>= 1)
if(i&1)
MD5Update(&ctx, final, 1);
else
MD5Update(&ctx, pw, 1);
/* Now make the output string */
strcpy(passwd,magic);
strncat(passwd,sp,sl);
strcat(passwd,"$");
MD5Final(final,&ctx);
/*
* and now, just to make sure things don't run too fast
* On a 60 Mhz Pentium this takes 34 msec, so you would
* need 30 seconds to build a 1000 entry dictionary...
*/
for(i=0;i<1000;i++) {
MD5Init(&ctx1);
if(i & 1)
MD5Update(&ctx1,pw,strlen(pw));
else
MD5Update(&ctx1,final,MD5_SIZE);
if(i % 3)
MD5Update(&ctx1,sp,sl);
if(i % 7)
MD5Update(&ctx1,pw,strlen(pw));
if(i & 1)
MD5Update(&ctx1,final,MD5_SIZE);
else
MD5Update(&ctx1,pw,strlen(pw));
MD5Final(final,&ctx1);
}
#ifdef __PIC__
dlclose(libmd);
#endif
p = passwd + strlen(passwd);
l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];
_crypt_to64(p,l,4); p += 4;
l = (final[ 1]<<16) | (final[ 7]<<8) | final[13];
_crypt_to64(p,l,4); p += 4;
l = (final[ 2]<<16) | (final[ 8]<<8) | final[14];
_crypt_to64(p,l,4); p += 4;
l = (final[ 3]<<16) | (final[ 9]<<8) | final[15];
_crypt_to64(p,l,4); p += 4;
l = (final[ 4]<<16) | (final[10]<<8) | final[ 5];
_crypt_to64(p,l,4); p += 4;
l = final[11] ;
_crypt_to64(p,l,2); p += 2;
*p = '\0';
/* Don't leave anything around in vm they could use. */
memset(final,0,sizeof final);
return passwd;
}
