jangko / nimaes Goto Github PK

For cryptCTR, if "nc_of" is not zero, as "stream_block" is initialized with zeroes, the beginning of the text is not encrypted.

Here is a small program which shows the error.

import nimAES
var cipher = initAES()
let key = "abcdefghijklmnop"
discard cipher.setEncodeKey(key)

let text = "Some text to show that there is an error."
echo "Text -> ", text

var offset: int = 0
var nonce = "0123456701234567"
var encrypted = cipher.cryptCTR(offset, nonce, text[0..20])
encrypted &= cipher.cryptCTR(offset, nonce, text[21..text.high])
echo "Encrypted -> ", encrypted
offset = 0
nonce = "0123456701234567"
var decrypted = cipher.cryptCTR(offset, nonce, encrypted)
echo "Decrypted -> ", decrypted

To solve the issue, it will be necessary to initialize "stream_block" with the last encrypted value of
the nonce, so, probably, to keep it in the context.

Note that there is no such problem with CFB128 mode as the offset is applied on the IV itself.

This error seems to occure with new nim 1.2.0 everytime I try to use setDecodeKey

Specifics :
filename = 0x56667a5c"/home/kittytechno/.nimble/pkgs/nimAES-0.1.2/nimAES.nim"], [procname = 0x56667aa0"setEncodeKey",
line = 184,
filename = 0x56667a5c"/home/kittytechno/.nimble/pkgs/nimAES-0.1.2/nimAES.nim"], [procname = 0x56662060"sysFatal",
line = 49,
filename = 0x56662069"/home/kittytechno/.choosenim/toolchains/nim-1.2.0/lib/system/fatal.nim"], [procname = nil,
line = -10,

Output from $ nimble install nimaes

Downloading https://github.com/jangko/nimAES using git Warning: File inside package 'nimAES' is outside of permitted namespace, should be named 'nimAES.nim' but was named 'test.nim' instead. This will be an error in the future. Hint: Rename this file to 'nimAES.nim', move it into a 'nimAES/' subdirectory, or prevent its installation by addingskipFiles = @["test.nim"]to the .nimble file. See https://github.com/nim-lang/nimble#libraries for more info. Verifying dependencies for [email protected] Installing [email protected] Success: nimAES installed successfully.

Still seems to work ok, just maybe update to the language styling.

Cheers

you have assert in one of encryptECB proc and another encryptECB encrypts only first 16 bytes. why?

Hey :)
I encountered a bug in CBC mode - tried to encrypt and decrypt a string, but seems like the first bytes are not decrypted well.
the code:

import nimAES

let communication_aes_key = "ieMhfhf!!56=z$V4fd*3t15f3.3ZZaw3"
let communication_aes_iv = "-+x3BBw3NN_=!s32"

proc encrypt_cbc(plain_text: string): string =
    var aes = initAES()
    if aes.setEncodeKey(communication_aes_key):
        let cipher_text = aes.encryptCBC(communication_aes_iv, plain_text)
        return cipher_text

proc decrypt_cbc(cipher_text: string): string =
    var aes = initAES()
    if aes.setDecodeKey(communication_aes_key):
        let plain_text = aes.decryptCBC(communication_aes_iv, cipher_text)
        return plain_text

let encrypted = encrypt_cbc("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa")
let decrypted = decrypt_cbc(encrypted)
echo decrypted

Thanks in advance :)

http://csrc.nist.gov/groups/STM/cavp/block-ciphers.html#test-vectors

When compiling any Nim program using NimAES, a very large .c file is generated (several MBs), which takes a long time to compile, uses up a large amount of memory during compilation making it impossibly ble to compile on low-memory systems (500-1000MB of RAM) and results in bigger executables.

This can be observed even when compiling the test program in this repository.

I never encountered this behavior in previous versions of Nim. Any idea why this is happening now?

Edit: i am an idiot