Hi all,
I have only recently started working with NIM and I am loving it but I have hit
a little stumbling block. I am trying to get some simple AES encryption working
and for the life of me I can't seem to be able to do it. I have no doubt some
AES experts on here will spot my mistake instantly.
Any chance you could have a go at running this code to see why I can't decrypt
the input please? The important bits are:
1. The key is KEYDEFGHIHKLOMNA
2. The IV is IVCDEFGHIHKLOMNA
3. The encrypted intput in AES CBC 128 is D9C69ED09EACB9A874FCBEB3DC054522
which is just my name davidkennedy encrypted on this site:
devglan.com/online-tools/aes-encryption-decryption
I have added some echo outputs to see what I think should be coming out the
other side but I never seem to be able to even get the hex version of my name
visible! I am using byte sequences to store the IV and Key as in my eventual
code that is what I will need to use. Thanks Here is the basic code:
import winim
import nimcrypto
import std/base64
## Converts a string to the corresponding byte sequence.
proc toByteSeq*(str: string): seq[byte] {.inline.} =
@(str.toOpenArrayByte(0, str.high))
func toString*(bytes: openArray[byte]): string {.inline.} =
## Converts a byte sequence to the corresponding string.
let length = bytes.len
if length > 0:
result = newString(length)
copyMem(result.cstring, bytes[0].unsafeAddr, length)
proc decrypt(encryptedInput: string, key: seq[byte], iv: seq[byte]):
seq[byte] =
# some var definitions for decrypting
let cryptedInput = toByteSeq(encryptedInput)
var
encodedPay = newSeq[byte](len(cryptedInput))
decodedPay = newSeq[byte](len(cryptedInput))
encodedPay = cryptedInput
# Decrypt the encrypted bytes of the main payload
var test: CBC[aes128]
test.init(key, iv)
test.decrypt(encodedPay, decodedPay)
test.clear()
echo "IV : ", toHex(iv)
echo "PLAIN TEXT HEX : ", toHex(encodedPay)
#echo "PLAIN TEXT: ", plaintext
echo "DECODED TEXT HEX: ", toHex(decodedPay)
echo "SHOULD BE HEX : 64617669646b656e6e656479" #Decrypted AES CBC128
of davidkennedy
echo "DECODED TEXT B64: ", encode(decodedPay)
echo "SHOULD BE B64 : ZGF2aWRrZW5uZWR5"
#echo "DECODED TEXT: ", decText
echo "String :", decodedPay.toString() # convert tranformed text to
string
when isMainModule:
let key: seq[byte] = toByteSeq("KEYDEFGHIHKLOMNA")
let iv: seq[byte] = toByteSeq("IVCDEFGHIHKLOMNA")
var encryptedInput = "D9C69ED09EACB9A874FCBEB3DC054522" #AES CBC128
encryption of davidkennedy in HEX
var code = decrypt(encryptedInput,key,iv)
Run
