#include <stdlib.h>
#include <sys/time.h>

#include "md5.h"
#include "random.h"
#include "externs.h"
#include "strings.h"

#include "pw-a.h"

/* don't casually change either of these; too many things depend on them */
static const char alphabet[] = "!\"#$%&'()*+,-./0123456789:;<=>?@"
			       "ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`"
			       "abcdefghijklmnopqrstuvwxyz{|}~";
#define BASE 94

static unsigned int base_div(unsigned char *v)
{
 unsigned int r;
 int i;

 r = 0;
 for (i=0;i<16;i++)
  { r = (r << 8) + v[i];
    v[i] = r / BASE;
    r %= BASE;
  }
 return(r);
}

static void base_expand(const unsigned char *res, char *txt)
{
 int i;
 unsigned char tmp[16];

 bcopy(res,&tmp[0],16);
 for (i=0;i<20;i++) txt[i] = alphabet[base_div(&tmp[0])];
}

int pw_a_check(const char *pass, const char *plain)
{
 void *s;
 unsigned char md5res[16];
 char text[20];

 if (strlen(pass) != 40) return(1);
 s = md5_init();
 md5_process_bytes(s,plain,strlen(plain));
 md5_process_bytes(s,pass,20);
 md5_result(s,&md5res[0]);
 base_expand(&md5res[0],&text[0]);
 return(bcmp(&text[0],pass+20,20));
}

char *pw_a_make(const char *plain)
{
 void *s;
 unsigned char binsalt[9];
 unsigned char md5res[16];
 char *text;
 struct timeval tv;

 text = malloc(41);
 gettimeofday(&tv,0);
 binsalt[0] =  tv.tv_sec        & 0xff;
 binsalt[1] = (tv.tv_sec >>  8) & 0xff;
 binsalt[2] = (tv.tv_sec >> 16) & 0xff;
 binsalt[3] = (tv.tv_sec >> 24) & 0xff;
 binsalt[4] = rndint();
 binsalt[5] =  tv.tv_usec        & 0xff;
 binsalt[6] = (tv.tv_usec >>  8) & 0xff;
 binsalt[7] = (tv.tv_usec >> 16) & 0xff;
 binsalt[8] = (tv.tv_usec >> 24) & 0xff;
 s = md5_init();
 md5_process_bytes(s,&binsalt[0],9);
 md5_result(s,&md5res[0]);
 base_expand(&md5res[0],text);
 s = md5_init();
 md5_process_bytes(s,plain,strlen(plain));
 md5_process_bytes(s,text,20);
 md5_result(s,&md5res[0]);
 base_expand(&md5res[0],text+20);
 text[40] = '\0';
 return(text);
}