Netscape's RNG

[Stephen Kapp]

In-Reply-To: <199508300512.BAA23185 at calum.csclub.uwaterloo.ca>
> -----8<-----8<-----
> struct RNG
> {
>     unsigned char md5bytes[0x10];
>     unsigned char randbytes[0x10];
>     int size;
>     void *md5data;
> };
> 
> RNG_GenerateRandomBytes(struct RNG *i0, char *i1, int i2)
> {
>     char buf[0x20];
>     int o1,o2;
> 
>     while (i2 > i0->size)
>     {
>       memcpy(i1, &(i0->randbytes)+0x10-i0->size, i0->size);
>       i1 += i0->size;
>       i2 -= io->size;
>       if (err = MD5_Begin(i0->md5data)) return err;
>       if (err = MD5_Update(i0->md5data, &(i0->md5bytes), 0x10)) return 
err;
>       if (err = MD5_End(i0->md5data, &(i0->randbytes), buf, 0x10)) 
return err;
>       i0->size = 0x10;
>       o2 = 0;
>       o1 = &(i0->md5bytes[0x0f]);
>       do
>       {
>           if ((*o1)++) break;
>           --o1;
>       } while (++o2 <= 0x0f);
>     }
> 
>     /* i2 <= i0->size */
>     memcpy(i1, &(i0->randbytes)+0x10-i0->size, i2);
>     i0->size -= i2;
>     return 0;
> }
> -----8<-----8<-----
> 

This looks very much like the RSAREF random number code, there are a few 
minor differences, but it still looks very similar.

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E-mail: skapp at cix.compulink.co.uk, 
        skapp at sourcery.demon.co.uk
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