#!/usr/bin/rexx
-- requires OORexx 4.2.0 or later
-- standard numeric digits of 9 is not enough in this case
::options digits 20
-- Implementation mainly based on pseudocode in https://en.wikipedia.org/wiki/MD5
::class md5 public
::method init
expose a0 b0 c0 d0 count buffer index K. s -- instance variables
use strict arg chunk=""
-- Initialize message digest
a0 = .int32~new('67452301'x,"C") -- A
b0 = .int32~new('efcdab89'x,"C") -- B
c0 = .int32~new('98badcfe'x,"C") -- C
d0 = .int32~new('10325476'x,"C") -- D
-- The 512 bit chunk buffer
buffer = .mutablebuffer~new('00'x~copies(64),64)
-- The position in the buffer to insert new input
index = 1
-- message bytecount
count = 0
-- initialize leftrotate amounts
nrs = .array~of(7,12,17,22)
s = nrs~union(nrs)~union(nrs)~union(nrs)
nrs = .array~of(5,9,14,20)
s = s~union(nrs)~union(nrs)~union(nrs)~union(nrs)
nrs = .array~of(4,11,16,23)
s = s~union(nrs)~union(nrs)~union(nrs)~union(nrs)
nrs = .array~of(6,10,15,21)
s = s~union(nrs)~union(nrs)~union(nrs)~union(nrs)
-- initialize sinus derived constants.
-- sin function from RXMath Library shipped with OORexx
-- see ::routine directive at the end of the code
do i=0 to 63
K.i = .int32~new(((2**32)*(sin(i+1,16,R)~abs))~floor)
end
-- process initial string if any
self~update(chunk)
exit
::method update
expose a0 b0 c0 d0 count buffer index K. s -- instance variables
use strict arg chunk
count += chunk~length
if chunk~length<65-index then do
buffer~overlay(chunk,index)
index += chunk~length
end
else do
split = 65-index+1
parse var chunk part =(split) chunk
buffer~overlay(part,index)
index = 65
end
-- Only proces completely filled buffer
do while index=65
A = a0
B = b0
C = c0
D = d0
do i=0 to 63
select
when i<16 then do
F = D~xor(B~and(C~xor(D)))
g = i
end
when i<32 then do
F = C~xor(D~and(B~xor(C)))
g = (5*i+1)//16
end
when i<48 then do
F = B~xor(C)~xor(D)
g = (3*i+5)//16
end
otherwise do
F = C~xor(B~or(D~not))
g = (7*i)//16
end
end
M = .int32~new(buffer~substr(g*4+1,4)~reverse,"C") -- 32bit word in little-endian
dTemp = D
D = C
C = B
B = (B + (A+F+K.i+M)~bitrotate(s[i+1]))
A = dTemp
end
a0 = a0+A
b0 = b0+B
c0 = c0+C
d0 = d0+D
parse var chunk part 65 chunk
index = part~length+1
buffer~overlay(part,1,part~length)
end
exit
::method digest
expose a0 b0 c0 d0 count buffer index K s -- instance variables
padlen = 64
if index<57 then padlen = 57-index
if index>57 then padlen = 121-index
padding = '00'x~copies(padlen)~bitor('80'x)
bitcount = count*8//2**64
lowword = bitcount//2**32
hiword = bitcount%2**32
lowcount = lowword~d2c(4)~reverse -- make it little-endian
hicount = hiword~d2c(4)~reverse -- make it little-endian
self~update(padding || lowcount || hicount)
return a0~string || b0~string || c0~string || d0~string
-- A convenience class to encapsulate operations on non OORexx-like
-- things such as little-endian 32-bit words
::class int32 private
::attribute arch class
::method init class
self~arch = "little-endian" -- can be adapted for multiple architectures
-- Method to create an int32 like object
-- Input can be a OORexx whole number (type="I") or
-- a character string of 4 bytes (type="C")
-- input truncated or padded to 32-bit word/string
::method init
expose char4 int32
use strict arg input, type="Integer"
-- type must be one of "I"nteger or "C"haracter
t = type~subchar(1)~upper
select
when t=='I' then do
char4 = input~d2c(4)
int32 = char4~c2d
end
when t=='C' then do
char4 = input~right(4,'00'x)
int32 = char4~c2d
end
otherwise do
raise syntax 93.915 array("IC",type)
end
end
exit
::method xor -- wrapper for OORexx bitxor method
expose char4
use strict arg other
return .int32~new(char4~bitxor(other~char),"C")
::method and -- wrapper for OORexx bitand method
expose char4
use strict arg other
return .int32~new(char4~bitand(other~char),"C")
::method or -- wrapper for OORexx bitor method
expose char4
use strict arg other
return .int32~new(char4~bitor(other~char),"C")
::method not -- OORexx not implementation
expose char4
return .int32~new(char4~bitxor('ffffffff'x),"C")
::method bitleft -- OORexx shift (<<) implementation
expose char4
use strict arg bits
bstring = char4~c2x~x2b
bstring = bstring~substr(bits+1)~left(bstring~length,'0')
return .int32~new(bstring~b2x~x2d)
::method bitright -- OORexx shift (>>) implementation
expose char4
use strict arg bits, signed=.false
bstring = char4~c2x~x2b
fill = '0'
if signed then fill = bstring~subchar(1)
bstring = bstring~left(bstring~length-bits)~right(bstring~length,fill)
return .int32~new(bstring~b2x~x2d)
::method bitrotate -- OORexx (left) rotate method
expose char4
use strict arg bits, direction='left'
d = direction~subchar(1)~upper
if d=='L' then do
leftpart = self~bitleft(bits)
rightpart = self~bitright(32-bits)
end
else do
leftpart = self~bitleft(32-bits)
rightpart = self~bitright(bits)
end
return rightpart~or(leftpart)
::method int -- retrieve integer as number
expose int32
return int32
::method char -- retrieve integer as characters
expose char4
return char4
::method string -- retrieve integer as hexadecimal string
expose char4
return char4~reverse~c2x~lower
::method '+' -- OORexx method to add 2 .int32 instances
expose int32
use strict arg other
return .int32~new(int32+other~int)
-- Simplify function names for the necessary 'RxMath' functions
::routine sin EXTERNAL "LIBRARY rxmath RxCalcSin"
