Re: [RFC][PATCH] Pseudo-random number generator

[Alan <alan@lxorguk.ukuu.org.uk>]

> * merging the s390 PRNG with the random pool implementation
> PRO: no new interface, random numbers can be read through /dev/urandom
> CON: complex implementation, could only use traditional /dev/urandom algorithm
>      or hardware-accelerated implementation

Also PRO: Can be verified by non-IBM people, high resistance if there is
a flaw (accidental or US government 8)) in the 390 hardware.

> I've chosen the char driver since it allows the user to decide which pseudo-random
> numbers he wants to use. That means there is a new interface for the s390
> PRNG, called /dev/prandom.

And people can pipe this into the urandom layer if they wish.

> +/* copied from libica, use a non-zero initial parameter block */
> +unsigned char parm_block[32] = {
> +0x0F,0x2B,0x8E,0x63,0x8C,0x8E,0xD2,0x52,0x64,0xB7,0xA0,0x7B,0x75,0x28,0xB8,0xF4,
> +0x75,0x5F,0xD2,0xA6,0x8D,0x97,0x11,0xFF,0x49,0xD8,0x23,0xF3,0x7E,0x21,0xEC,0xA0,
> +};
> +

Global variables called "p" and "parm_block". Plus parm_block appears to
be const

Also your register the misc device before allocating the buffer so it can
be opened in theory before the alloc is done and crash.