import std/[sequtils,strformat,strutils, sugar]

proc toEvenHex(bytes: seq[uint8], sizeNeeded: int8): seq[string] =

let

hex = bytes.toSeq.mapIt(it.toHex.toLower)

offset = hex.len.mod(sizeNeeded)

remainder = case offset:

of 0: 0

else: sizeNeeded - offset

padding = @["90"].cycle(remainder)

#echo "Offset: ", offset, " Remainder: ", remainder

writeLine(stderr, &"[*] Shellcode is {hex.len} bytes, adding {remainder} NOPs to make payload")

return concat(padding, hex) # add NOP sled to make the sequence evenly devisible

proc toUUIDs*(bytes: seq[uint8]): seq[string] =

let hex = bytes.toEvenHex(16)

result = collect:

for i in countup(0, hex.len-16, 16):

let uuidGroups = hex[i ..< i+16].distribute(4)

&"{uuidGroups[0].join}-{uuidGroups[1].join}-{uuidGroups[2].join}{uuidGroups[3].join}"

proc fromUUID*(uuid: string): seq[uint8] =

let bytes = uuid

.filterIt(it != '-')

.distribute(16)

.mapIt(fromHex[uint8](join(it)))

result = collect(newSeq):

for b in bytes: b

proc toMAC*(bytes: seq[uint8]): seq[string] =

let hex = bytes.toEvenHex(8)

for i in countup(0, hex.len-8, 8):

let mac = hex[i ..< i+8].join("-")

result.add(mac)

proc fromMAC*(mac: string): seq[uint8] =

result = mac.split(".").mapIt(cast[uint8](it.parseUInt))

proc toIPv6*(bytes: seq[uint8]): seq[string] =

let hex = bytes.toEvenHex(16)

result = collect:

for i in countup(0, hex.len-16, 16):

let uuidGroups = hex[i ..< i+16].distribute(4)

join(uuidGroups.mapIt(join(it)),":")

#let uuid = &"{uuidGroups[0].join(":")}:{uuidGroups[1].join(":")}:{uuidGroups[2].join(":")}{uuidGroups[3].join(":")}"

proc fromIPv6*(ipv6: string): seq[uint8] =

let bytes = ipv6

.filterIt(it != ':')

.distribute(16)

.mapIt(fromHex[uint8](join(it)))

result = collect:

for b in bytes: b

proc toIPv4*(bytes: seq[uint8]): seq[string] =

let

remainder = 4 - bytes.len.mod(4)

buffer = @[144'u8].cycle(remainder) # 144d = 90h (NOP)

alignedBytes = concat(buffer, bytes)

for i in countup(0, alignedBytes.len-4, 4):

result.add(alignedBytes[i ..< i+4].join("."))

proc fromIPv4*(ipv4: string): seq[uint8] =

result = ipv4.split(".").mapIt(cast[uint8](it.parseUInt))