public
Last active

Badcode: A child's attempt at a SHA256 hash implementation and a cipher inspired by AES.

  • Download Gist
gistfile1.lua
Lua
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684
--[[
 
the Advanced Roblox CryptoSystem, or ARCS, is being designed to bring better security to roblox games, such as private servers.
While still in its infancy, hopefully one day, ARCS will become a suitable means of data encryption.
 
ARCS currently supplies 2 features.
 
A secure Hash function,
And secure encryption algorithm.
 
 
The secure Hash algorithm (A SHA256 variant), can be called with the Hash() function.
It has 1 input, which is the text to be hashed.
 
print(ARCS.Hash("Some Random Data"))
-->28551017D06B84BD97742D373E60D4CF6D1D863E3817A7CB7058B824204194A6
 
 
ARCS also includes the ARCS Cipher, is a (hopefully) secure encryption algorithm.
The cipher has 3 inputs, the text to be encrypted, the key to use, and the number of rounds (optional)
You can use ARCS.CipherEN to encrypt, and ARCS.CipherDE to decrypt
 
print(ARCS.CipherEN("HOLY SHNAPPLE","WHAT 9000!?!?!?"))
-->36FF255D11705BDF5939208F7C25BE54B20992B45265ACE387551AE4798D5D5F
 
print(ARCS.CipherDE("36FF255D11705BDF5E12208C7C25BE5493BE8F2C200F55FC26CD2C3EE4D49D6E","WHAT 9000!?!?!?"))
-->HOLY SHNAPPLE 08/16/10 13:53:42 0016
 
(The number of rounds is -not- required when decrypting, even if the string has been encrypted with more than 16)
 
the decryption function will return two strings, the decrypted text, and the decrypted header.
The header is a 16 character string of text included at the begining of the cipher text.
The header includes the time and date of when the encryption was started for that string, and
the number of rounds it was encrypted with.
 
Currently, the ARCS cipher is a variable strength cipher, in the sense, that you can use more rounds in the encryption.
The main portion of the encryption consits of a function that systematically encrypts the text.
When you encrypt something, its encrypted in stages, each stage is a round. Each round is just the main portion of the cipher,
but it is repeated over and over again to offer more security. There is a mininum of 16 rounds, and a maximum of 9999.
 
It should also be noted that the header string is always encrypted with 16 rounds, which is strong enough to protect the inocous data
held within it.
 
The ARCS Cipher currently is not exactly how I would like it to be, so there will most likely be several updates in the comming days,
to improve security, and efficiency.
 
Please check back every once in a while to ensure that you are using the most up-to-date version of ARCS.
 
]]--
 
ARCS = {}
 
function XOR(in1, in2)
final = ""
for i=1,#in1 do
x1 = in1:sub(i,i)
x2 = in2:sub(i,i)
if x1 == x2 then
final = final .. "0"
else
final = final .. "1"
end
end
return final
end
 
function AND(in1, in2)
final = ""
for u=1,#in1/8 do
x1 = in1:sub(u*8-7,u*8)
x2 = in2:sub(u*8-7,u*8)
local out = ""
for i=1,8 do
i1 = x1:sub(i,i)
i2 = x1:sub(i,i)
if i1 == i2 then
out = out .. "1"
elseif i1 ~= i2 then
out = out .. "0"
end
end
final = final .. out
end
return final
end
 
function NOT(in1)
final = ""
for u=1,#in1/8 do
x1 = in1:sub(u*8-7,u*8)
local out = ""
for i=1,8 do
i1 = x1:sub(i,i)
i2 = x1:sub(i,i)
if i1 == "1" then
out = out .. "0"
else
out = out .. "1"
end
end
final = final .. out
end
return final
end
 
function OR(in1,in2)
local out = ""
for i=1,8 do
i1 = in1:sub(i,i)
i2 = in2:sub(i,i)
if i1 == "1" or i2 == "1" then
out = out .. "1"
else
out = out .. "0"
end
end
return out
end
 
function LeftShift(x,n)
y=#x
x = x:sub(n+1,32)
x = x .. string.rep("0",32-#x)
return x
end
 
function RightShift(x,n)
y=#x
x = x:sub(1,n)
x = string.rep("0",32-n) .. x
return x
end
 
function RightRotate(x,n)
return x:sub(n+1,#x) .. x:sub(1,n)
end
 
 
function moduloAdd(txt1,txt2,x)
if not x then x = 32 end
txt1 = bToDec(txt1)
txt2 = bToDec(txt2)
txt = (txt1 + txt2) % 2^x
final = nToBin(txt,x)
return final
end
 
function columTran(txt)
local tmp = {}
for i=1,16 do
tmp[i] = txt:sub(i*8-7,i*8)
end
local final = ""
local x,y = -3,1
repeat
x = (x + 4)
if x > 16 then
y = y + 1
x = y
end
final = final .. tmp[x]
until x == 16
return final
end
 
function shiftRow(txt,way)
if not way then
local tmp = {}
for i=1,4 do
tmp[i] = txt:sub(i*32-31,i*32)
end
tmp[2] = RightRotate(tmp[2],8)
tmp[3] = RightRotate(tmp[3],16)
tmp[4] = RightRotate(tmp[4],24)
return table.concat(tmp)
elseif way then
local tmp = {}
for i=1,4 do
tmp[i] = txt:sub(i*32-31,i*32)
end
tmp[2] = RightRotate(tmp[2],24)
tmp[3] = RightRotate(tmp[3],16)
tmp[4] = RightRotate(tmp[4],8)
return table.concat(tmp)
end
end
 
function cToHex(text)
final = ''
for i=1,#text do
work = string.format("%X",text:sub(i,i):byte())
if #work == 1 then
work = "0"..work
end
final = final .. work
end
return final
end
 
function hToBin(char)
local final = ""
for i=1,#char/2 do
local fix = 0
fix = tonumber(char:sub(i*2-1,i*2),16)
final = final .. nToBin(fix)
end
return final
end
 
function nToBin(Decimal,x)
if x == nil then x = 8 end
local BinaryRep = ""
local Number = Decimal
while Number > 0 do
BinaryRep = BinaryRep .. Number % 2
Number = math.floor(Number / 2)
end
return Decimal == 1 and ("0"):rep(x-1) .. "1" or ("0"):rep(x - BinaryRep:len()) .. BinaryRep:reverse()
end
 
function nToHex(num)
return string.format("%X",num)
end
 
function bToHex(txt)
rfinal = ""
for u=1,#txt/8 do
bin = tostring(txt:sub(u*8-7,u*8))
local final = ""
for i=1,8,4 do
local fix = bin:sub(i,i+3)
local subtotal = 0
local o = 0
for u=4,1,-1 do
local fx = fix:sub(u,u)
if fx == "1" then
subtotal = subtotal + 2^(o)
end
o = o +1
end
if subtotal > 9 then
subtotal = string.char(subtotal+55)
end
final = final .. subtotal
end
rfinal = rfinal .. final
end
return rfinal
end
 
function hToDec(text)
return tonumber(text,16)
end
 
function bToDec(text)
return tonumber(text,2)
end
 
function hToChar(text)
final = ""
for i=1,#text/2 do
work = text:sub(i*2-1,i*2)
work = hToDec(work)
work = string.char(work)
final = final .. work
end
return final
end
 
function bToChar(text)
final = ""
for i=1,#text/8 do
work = text:sub(i*8-7,i*8)
final = final .. string.char(tonumber(work,2))
end
return final
end
 
function cToBin(text)
final = ""
for i=1,#text do
final = final .. nToBin(text:sub(i,i):byte())
end
return final
end
 
function sMod(num,base)
if num == base then
return 1
else
return num % base
end
end
 
 
function XinY(num,base)
local x = 0
while num >= base do
num = num - base
x=x+1
end
return x
end
 
function nextInt(num,base)
y = XinY(num,base) + 1
return base*y - num
end
 
 
Blocks={}
HVal = {}
Blocks[0] = {}
Constants = {}
Constants[0] = "01000010100010100010111110011000"
Constants[1] = "01110001001101110100010010010001"
Constants[2] = "10110101110000001111101111001111"
Constants[3] = "11101001101101011101101110100101"
Constants[4] = "00111001010101101100001001011011"
Constants[5] = "01011001111100010001000111110001"
Constants[6] = "10010010001111111000001010100100"
Constants[7] = "10101011000111000101111011010101"
Constants[8] = "11011000000001111010101010011000"
Constants[9] = "00010010100000110101101100000001"
Constants[10] = "00100100001100011000010110111110"
Constants[11] = "01010101000011000111110111000011"
Constants[12] = "01110010101111100101110101110100"
Constants[13] = "10000000110111101011000111111110"
Constants[14] = "10011011110111000000011010100111"
Constants[15] = "11000001100110111111000101110100"
Constants[16] = "11100100100110110110100111000001"
Constants[17] = "11101111101111100100011110000110"
Constants[18] = "00001111110000011001110111000110"
Constants[19] = "00100100000011001010000111001100"
Constants[20] = "00101101111010010010110001101111"
Constants[21] = "01001010011101001000010010101010"
Constants[22] = "01011100101100001010100111011100"
Constants[23] = "01110110111110011000100011011010"
Constants[24] = "10011000001111100101000101010010"
Constants[25] = "10101000001100011100011001101101"
Constants[26] = "10110000000000110010011111001000"
Constants[27] = "10111111010110010111111111000111"
Constants[28] = "11000110111000000000101111110011"
Constants[29] = "11010101101001111001000101000111"
Constants[30] = "00000110110010100110001101010001"
Constants[31] = "00010100001010010010100101100111"
Constants[32] = "00100111101101110000101010000101"
Constants[33] = "00101110000110110010000100111000"
Constants[34] = "01001101001011000110110111111100"
Constants[35] = "01010011001110000000110100010011"
Constants[36] = "01100101000010100111001101010100"
Constants[37] = "01110110011010100000101010111011"
Constants[38] = "10000001110000101100100100101110"
Constants[39] = "10010010011100100010110010000101"
Constants[40] = "10100010101111111110100010100001"
Constants[41] = "10101000000110100110011001001011"
Constants[42] = "11000010010010111000101101110000"
Constants[43] = "11000111011011000101000110100011"
Constants[44] = "11010001100100101110100000011001"
Constants[45] = "11010110100110010000011000100100"
Constants[46] = "11110100000011100011010110000101"
Constants[47] = "00010000011010101010000001110000"
Constants[48] = "00011001101001001100000100010110"
Constants[49] = "00011110001101110110110000001000"
Constants[50] = "00100111010010000111011101001100"
Constants[51] = "00110100101100001011110010110101"
Constants[52] = "00111001000111000000110010110011"
Constants[53] = "01001110110110001010101001001010"
Constants[54] = "01011011100111001100101001001111"
Constants[55] = "01101000001011100110111111110011"
Constants[56] = "01110100100011111000001011101110"
Constants[57] = "01111000101001010110001101101111"
Constants[58] = "10000100110010000111100000010100"
Constants[59] = "10001100110001110000001000001000"
Constants[60] = "10010000101111101111111111111010"
Constants[61] = "10100100010100000110110011101011"
Constants[62] = "10111110111110011010001111110111"
Constants[63] = "11000110011100010111100011110010"
 
function miniReset()
for i=0,7 do
HVal[i] = Blocks[0][i]
end
end
 
function largeReset()
Blocks[0][0] = "01101010000010011110011001100111"
Blocks[0][1] = "10111011011001111010111010000101"
Blocks[0][2] = "00111100011011101111001101110010"
Blocks[0][3] = "10100101010011111111010100111010"
Blocks[0][4] = "01010001000011100101001001111111"
Blocks[0][5] = "10011011000001010110100010001100"
Blocks[0][6] = "00011111100000111101100110101011"
Blocks[0][7] = "01011011111000001100110100011001"
end
 
largeReset()
for i=0,63 do Constants[i] = hToBin(Constants[i]) end
 
function ARCS.Hash(text)
text = tostring(text)
--String preprocessing
local tmp = cToBin(text)
tml = #tmp
local nextI = nextInt(tml+65,512)
tmp = tmp .. "1" .. string.rep("0",nextI)
local append = nToBin(#text)
append = string.rep("0",64-#append) .. append
text = tmp .. append
local nB = XinY(#text,512)
largeReset()
for i=1,nB do
Blocks[i] = {}
Blocks[i].String=text:sub(i*512-511,i*512)
end
--Block preprocessing
for i=1,nB do
work = Blocks[i].String
for u=0,15 do
Blocks[i][u] = Blocks[i].String:sub((u+1)*32-31,(u+1)*32)
end
for u=16,63 do
s0 = XOR(RightRotate(Blocks[i][u-15],7),RightRotate(Blocks[i][u-15],18))
s0 = XOR(s0,RightRotate(Blocks[i][u-15],3))
s1 = XOR(RightRotate(Blocks[i][u-2],17),RightRotate(Blocks[i][u-2],19))
s1 = XOR(s1,RightRotate(Blocks[i][u-2],10))
step1 = moduloAdd(Blocks[i][u-16],s0)
step1 = moduloAdd(step1,Blocks[i][u-7])
Blocks[i][u] = moduloAdd(step1,s1)
end
end
--Getting to the actual hash now
for i=1,nB do
miniReset()
for o=0,63 do
local s0 = XOR(RightRotate(HVal[0],2),RightRotate(HVal[0],13))
s0 = XOR(s0,RightRotate(HVal[0],22))
local maj = XOR(AND(HVal[0],HVal[1]),AND(HVal[0],HVal[2]))
maj = XOR(maj,AND(HVal[1],HVal[2]))
local t2 = moduloAdd(s0,maj)
local s1 = XOR(RightRotate(HVal[4],6),RightRotate(HVal[4],11))
s1 = XOR(s1,RightRotate(HVal[4],25))
local ch = XOR(AND(HVal[4],HVal[5]),AND(NOT(HVal[4]),HVal[6]))
local t1 = moduloAdd(HVal[7],s1)
t1 = moduloAdd(t1,ch)
t1 = moduloAdd(t1,Constants[o])
t1 = moduloAdd(t1,Blocks[i][o])
HVal[7] = HVal[6]
HVal[6] = HVal[5]
HVal[5] = HVal[4]
HVal[4] = moduloAdd(HVal[3],t1)
HVal[3] = HVal[2]
HVal[2] = HVal[1]
HVal[1] = HVal[0]
HVal[0] = moduloAdd(t1,t2)
end
for o=0,7 do
Blocks[i][o] = moduloAdd(Blocks[i-1][o],HVal[o])
end
end
FINAL = ""
for i=0,7 do
FINAL = FINAL .. bToHex(Blocks[nB][i])
end
return FINAL
end
 
HEX = {"0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F","0000","0001","0010","0011","0100","0101","0110","0111","1000","1001","1010","1011","1100","1101","1110","1111"}
SHIFT = {23, 27, 33, 41, 51, 63, 77, 93, 111, 131, 153, 177, 203, 231, 261, 293, 327, 363, 401, 441, 483, 527, 573, 621, 671, 723, 777, 833, 891, 951, 1013, 1077, 1143, 1211, 1281, 1353, 1427, 1503, 1581, 1661, 1743, 1827, 1913, 2001, 2091, 2183, 2277, 2373, 2471, 2571, 2673, 2777, 2883, 2991, 3101, 3213, 3327, 3443, 3561, 3681, 3803, 3927, 4053, 4181, 4311, 4443, 4577, 4713, 4851, 4991, 5133, 5277, 5423, 5571, 5721, 5873, 6027, 6183, 6341, 6501, 6663, 6827, 6993, 7161, 7331, 7503, 7677, 7853, 8031, 8211, 8393, 8577, 8763, 8951, 9141, 9333, 9527, 9723, 9921, 10121, 10323, 10527, 10733, 10941, 11151, 11363, 11577, 11793, 12011, 12231, 12453, 12677, 12903, 13131, 13361, 13593, 13827, 14063, 14301, 14541, 14783, 15027, 15273, 15521, 15771, 16023, 16277, 16533, 16791, 17051, 17313, 17577, 17843, 18111, 18381, 18653, 18927, 19203, 19481, 19761, 20043, 20327, 20613, 20901, 21191, 21483, 21777, 22073, 22371, 22671, 22973, 23277, 23583, 23891, 24201, 24513, 24827, 25143, 25461, 25781, 26103, 26427, 26753, 27081, 27411, 27743, 28077, 28413, 28751, 29091, 29433, 29777, 30123, 30471, 30821, 31173, 31527, 31883, 32241, 32601, 32963, 33327, 33693, 34061, 34431, 34803, 35177, 35553, 35931, 36311, 36693, 37077, 37463, 37851, 38241, 38633, 39027, 39423, 39821, 40221, 40623, 41027, 41433, 41841, 42251, 42663, 43077, 43493, 43911, 44331, 44753, 45177, 45603, 46031, 46461, 46893, 47327, 47763, 48201, 48641, 49083, 49527, 49973, 50421, 50871, 51323, 51777, 52233, 52691, 53151, 53613, 54077, 54543, 55011, 55481, 55953, 56427, 56903, 57381, 57861, 58343, 58827, 59313, 59801, 60291, 60783, 61277, 61773, 62271, 62771, 63273, 63777, 64283, 64791, 65301, 65813}
function genSBox(seed)
local Key = seed
local SBox = {}
for i=2,16 do
work = seed:sub(i*16-15,i*16)
fin = XOR(work:sub(1,8),work:sub(9,16))
end
local nx,ny = bToDec(fin:sub(5,8)),bToDec(fin:sub(1,4))
of = SHIFT[bToDec(fin)%256+1]
local tmp = {}
local IBox= {}
for y=0,15 do
tmp[y] = {}
SBox[y] = {}
for x=0,15 do
SBox[y][x] = nToBin((y*of+ny)%16,4)..nToBin((x*of+nx)%16,4)
tmp[y][x] = nToBin((y*of+ny)%16,4)..nToBin((x*of+nx)%16,4)
end
end
for i=0,15 do
for x=0,15 do
tmp[x][i] = SBox[(x*(of*2+1)+1+i)%16][i]
end
end
local SBox = {}
local IBox = {}
for i=0,15 do
SBox[HEX[17+i]] = {}
for x=0,15 do
p1,p2,p3 = HEX[17+i],HEX[17+x],tmp[i][(x*of+1+i)%16]
SBox[p1][p2] = p3
if IBox[p3:sub(1,4)] == nil then
IBox[p3:sub(1,4)] = {}
end
IBox[p3:sub(1,4)][p3:sub(5,8)] = p1 .. p2
end
end
tmp = nil
return SBox,IBox
end
 
function SubByte(txt,tab)
final = ""
for i=1,#txt/8 do
p1,p2 = txt:sub(i*8-7,i*8-4),txt:sub(i*8-3,i*8)
final = final .. tab[p1][p2]
end
return final
end
 
 
function ARCS.CipherEN(txt,key,rounds)
Key = hToBin(ARCS.Hash(key)) -- Creates a stronger key
if not rounds or rounds < 16 then --makes sure you use proper round values
rounds = 16
end
if rounds > 9999 then
rounds = rounds % 9999 + 1
end
IV = os.date() -- Sets up the initial CBC (cipher block chaining) vector
IV = string.gsub(string.gsub(IV:sub(1,8) .. IV:sub(10,17),"/",""),":","")
IV = IV .. string.rep("0",16-(#IV+#tostring(rounds))) .. rounds
ttxt = txt .. string.char(3) ..string.rep(string.char(1),nextInt(#txt+1,16))
PTxt = cToBin(IV .. ttxt) -- translates everything into binary for INCREASED speed
PTxt = XOR(PTxt:sub(1,128),Key:sub(1,128)) .. PTxt:sub(129,#PTxt)
nB = XinY(#PTxt,128)
local Blocks = {}
Blocks[1] = PTxt:sub(1,128)
for u=2,nB do -- breaks message into 128 bit (16 character) blocks
Blocks[u] = XOR(PTxt:sub(u*128-127,u*128),Blocks[u-1])
end
TEXT = hToBin(ARCS.Hash(bToChar(Key)))
SBox = genSBox(Key) -- generating the key dependant S-Box
KBox = genSBox(TEXT) -- generating the secondary key dependant S-Box (used for key expansion)
KEYS = {}
KEYS[0] = Key
for i=1,rounds+1 do
tmp = XOR(KEYS[i-1],XOR(SubByte(KEYS[i-1],SBox),SubByte(KEYS[i-1],KBox))) -- Turns 1, 256bit key into the required number of 256 bit keys
KEYS[i] = RightRotate(tmp,(i%64)+1)
end
TMP = Blocks[1]
for u=1,2 do
TMP = XOR(TMP,KEYS[0]:sub(u*128-127,u*128))
end
for u=1,2 do -- encrypts the header with 16 rounds, always, ALWAYS
for i=1,16 do
TMP = SubByte(TMP,SBox)
TMP = shiftRow(TMP)
TMP = XOR(TMP,KEYS[i]:sub(u*128-127,u*128))
end
end
TMP = SubByte(TMP,SBox)
TMP = shiftRow(TMP)
for u=1,2 do
TMP = XOR(TMP,KEYS[17]:sub(u*128-127,u*128))
end
Blocks[1] = TMP
for Z=2,nB do
TMP = Blocks[Z]
for u=1,2 do
TMP = XOR(TMP,KEYS[0]:sub(u*128-127,u*128))
end
for u=1,2 do
for i=1,rounds do
TMP = SubByte(TMP,SBox)
TMP = shiftRow(TMP)
TMP = XOR(TMP,KEYS[i]:sub(u*128-127,u*128))
TMP = RightRotate(TMP,i%64+1)
end
end
TMP = SubByte(TMP,SBox)
TMP = shiftRow(TMP)
for u=1,2 do
TMP = XOR(TMP,KEYS[rounds+1]:sub(u*128-127,u*128))
end
TMP = RightRotate(TMP,(rounds+1)%64+1)
Blocks[Z] = TMP
end
FINAL = ""
for i=1,nB do
FINAL = FINAL .. bToHex(Blocks[i])
end
return FINAL
end
 
function ARCS.CipherDE(txt,key,rounds)
if not rounds or rounds < 16 then
rounds = 16
end
if rounds > 9999 then
rounds = rounds % 9999 + 1
end
Key = hToBin(ARCS.Hash(key))
PTxt = hToBin(txt)
nB = XinY(#PTxt,128)
local Blocks = {}
for u=1,nB do -- breaks message into 128 bit (16 character) blocks
Blocks[u] = PTxt:sub(u*128-127,u*128)
end
TEXT = hToBin(ARCS.Hash(bToChar(Key)))
SBox,IBox = genSBox(Key) -- generating the key dependant S-Box
KBox = genSBox(TEXT) -- generating the secondary key dependant S-Box (used for key expansion)
KEYS = {}
KEYS[0] = Key
for i=1,rounds+1 do
tmp = XOR(KEYS[i-1],XOR(SubByte(KEYS[i-1],SBox),SubByte(KEYS[i-1],KBox))) -- Turns 1, 256bit key into 98 256 bit keys
KEYS[i] = RightRotate(tmp,(i%64)+1)
end
TMP = Blocks[1]
for u=2,1,-1 do
TMP = XOR(TMP,KEYS[17]:sub(u*128-127,u*128))
end
TMP = shiftRow(TMP,true)
TMP = SubByte(TMP,IBox)
for u=2,1,-1 do -- encrypts the header with 16 rounds, always, ALWAYS
for i=16,1,-1 do
TMP = XOR(TMP,KEYS[i]:sub(u*128-127,u*128))
TMP = shiftRow(TMP,true)
TMP = SubByte(TMP,IBox)
end
end
for u=1,2 do
TMP = XOR(TMP,KEYS[0]:sub(u*128-127,u*128))
end
FINAL = {}
for i=1,nB do
FINAL[i] = {}
end
FINAL[1] = TMP
HEADER = bToChar(XOR(TMP,Key:sub(1,128)))
nRnds = tonumber(HEADER:sub(#HEADER-3,#HEADER))
if nRnds then
if nRnds > rounds then
for i=rounds,nRnds+1 do
tmp = XOR(KEYS[i-1],XOR(SubByte(KEYS[i-1],SBox),SubByte(KEYS[i-1],KBox))) -- Turns 1, 256bit key into 98 256 bit keys
KEYS[i] = RightRotate(tmp,(i%64)+1)
end
end
rounds = nRnds
for Z=2,nB do
TMP = Blocks[Z]
TMP = RightRotate(TMP,128-((rounds+1)%64+1))
for u=2,1,-1 do
TMP = XOR(TMP,KEYS[rounds+1]:sub(u*128-127,u*128))
end
TMP = shiftRow(TMP,true)
TMP = SubByte(TMP,IBox)
for u=2,1,-1 do
for i=rounds,1,-1 do
TMP = RightRotate(TMP,128-(i%64+1))
TMP = XOR(TMP,KEYS[i]:sub(u*128-127,u*128))
TMP = shiftRow(TMP,true)
TMP = SubByte(TMP,IBox)
end
end
for u=2,1,-1 do
TMP = XOR(TMP,KEYS[0]:sub(u*128-127,u*128))
end
FINAL[Z] = TMP
end
FINALans = ""
for u=2,nB do -- breaks message into 128 bit (16 character) blocks
work = bToChar(XOR(FINAL[u],FINAL[u-1]))
found = work:find(string.char(3))
if found then
work = work:sub(1,found-1)
end
FINALans = FINALans .. work
end
HEADER = HEADER:sub(1,2) .. "/" .. HEADER:sub(3,4) .. "/" .. HEADER:sub(5,6) .. " ".. HEADER:sub(7,8) .. ":" .. HEADER:sub(9,10) .. ":" .. HEADER:sub(11,12) .. " " .. HEADER:sub(13,16)
return FINALans,HEADER
else
return "Invalid Key or corrupted file"
end
end

Please sign in to comment on this gist.

Something went wrong with that request. Please try again.