kolibrios-gitea/programs/network/ssh/random.inc
hidnplayr 4f24fcab0f Pad with 0 bytes before encryption is set, as not to leak any entropy of RNG.
Little improved RNG seeding.
Fixed bug in MAC counter for SSH transport.

git-svn-id: svn://kolibrios.org@9071 a494cfbc-eb01-0410-851d-a64ba20cac60
2021-07-21 10:53:13 +00:00

126 lines
3.2 KiB
PHP

; ----------------------------- MOTHER.ASM -----------------------------
; Mother-of-All random number generator by Agner Fog 1998
; 32-bit mode version for 80x86 and compatible microprocessors
;
; MRandom returns a floating point number between 0 and 1.
; MRandomInit must be called before the first call to MRandom.
;
; C++ prototypes:
; extern "C" void MRandomInit (int seed);
; extern "C" double MRandom (void);
; extern "C" int MIRandom (int min, int max);
;
; © 1998, 2004 Agner Fog.
; GNU General Public License www.gnu.org/copyleft/gpl.html
; ----------------------------------------------------------------------
; The MRandom function is optimized for the Pentium microprocessor.
iglobal
mf3 dd 2111111111 ; factors
mf2 dd 1492
mf1 dd 1776
mf0 dd 5115
endg
uglobal
m0 dd ? ; history buffer
m1 dd ?
m2 dd ?
m3 dd ?
mc dd ?
temprng dq ? ; used for conversion to float
endg
proc init_random
xor ecx, ecx
; make random numbers and put them into buffer
@@:
imul eax, 29943829
dec eax
mov [m0+ecx*4], eax
inc ecx
cmp ecx, 5
jb @r
push edi
mov edi, 19
@@:
call MRandom
fstp st0
dec edi
jnz @r
pop edi
ret
endp
proc MRandom
call MBRandom ; random bits
mov edx, eax ; fast conversion to float
shr eax, 12
or eax, 3ff00000h
shl edx, 20
mov dword[temprng+4], eax
mov dword[temprng], edx
fld1
fld [temprng] ; partial memory stall here
fsubr st0, st1
ret
endp
proc MIRandom, max, min ; make random integer in desired interval
call MBRandom ; make random number
mov edx, [max]
mov ecx, [min]
sub edx, ecx
js .error ; max < min
inc edx ; max - min + 1
mul edx ; multiply random number by interval and truncate
lea eax, [edx+ecx] ; add min
ret
.error:
mov eax, 80000000h ; error exit
ret
endp
proc MBRandom
push edi
mov eax, [mf3]
mul [m3] ; x[n-4]
mov ecx, eax
mov eax, [m2] ; x[n-3]
mov edi, edx
mov [m3], eax
mul [mf2]
add ecx, eax
mov eax, [m1] ; x[n-2]
adc edi, edx
mov [m2], eax
mul [mf1]
add ecx, eax
mov eax, [m0] ; x[n-1]
adc edi, edx
mov [m1], eax
mul [mf0]
add eax, ecx
adc edx, edi
add eax, [mc]
adc edx, 0
mov [m0], eax
mov [mc], edx
pop edi
ret
endp