AES encrypt

General
1

Hello all,
i’m making a solution to generate QRcode for a Pepsi drink machine, the machine read the code and fills the glass with the requested drink.
I’ve made all with this library:
https://www.chilkatsoft.com/

It works all flawless, but i have to buy it after 30 days of testing.
I’ve found that also MonkeyBread plugins has crypto function, and i’ve got a developer license.
but i can’t figure out how to achieve the same result with mbs, here is my original code, someone can show me the path:


Dim uts,bevanda As String

Dim crypt As New Chilkat.Crypt2
crypt.CryptAlgorithm = "aes"
crypt.CipherMode = "cbc"

crypt.KeyLength = 128
crypt.PaddingScheme = 0
crypt.EncodingMode = "hex"

// An initialization vector is required if using CBC mode.
// ECB mode does not use an IV.
// The length of the IV is equal to the algorithm's block size.
// It is NOT equal to the length of the key.
Dim ivHex As String
ivHex = "6d5a7134743777217a25432a462d4a61"
crypt.SetEncodedIV ivHex,"hex"

// The secret key must equal the size of the key.  For
// 256-bit encryption, the binary secret key is 32 bytes.
// For 128-bit encryption, the binary secret key is 16 bytes.
Dim keyHex As String
keyHex = "34753778214125442a472d4b61506453"
crypt.SetEncodedKey keyHex,"hex"

// Encrypt a string...
// The input string is 44 ANSI characters (i.e. 44 bytes), so
// the output should be 48 bytes (a multiple of 16).
// Because the output is a hex string, it should
// be 96 characters long (2 chars per byte).
Dim encStr As String
uts = unixts()

bevanda = "0000" + bev.text
encStr = crypt.EncryptStringENC("00099MEX020091" + uts + bic.Text + bevanda.Right(4))
System.DebugLog("QRCODE:" + " 0"  + encStr)

thanks so much and happy new year

1 Like
2

Note that Xojo has native AES in the Crypto module now as a possible option: Crypto.AESEncrypt - Xojo Documentation

1 Like
3

Are you asking how NOT to pay for a software?

4

If you use MBS Xojo Plugins, you can also check CipherMBS class.

5

Absolutly not, i pay for all software that i use, as said i’ve got a developer license of MBS,
I asked for an alternative solution, if available.

1 Like
6

thanks @Matthew_Dinmore1, i will make a check.

7

thanks @Christian_Schmitz, i didn’t see that class, i will try it.

8

Hi @Christian_Schmitz ,
i’ve tryed the CipherMBS class, but i think i’m missing something.
Here is my code:

dim textToCrypt,back AS string
textToCrypt =  "00023MAX010491" + uts + bic.Text + bevanda.Right(4)
dim c as CipherMBS = CipherMBS.aes_128_cbc
dim CKey as MemoryBlock = "4u7x!A!D*G-AwXdS"
dim CIV as MemoryBlock = "mZf4t6w!z%C*F-Ja"

call c.EncryptInit Ckey, CIV

dim output1 as string = c.ProcessString(textToCrypt)
output1 = output1 + c.FinalizeAsString

dim a as new AESMBS

call a.SetKey(CKey, 128)
dim output2 as MemoryBlock
a.EncryptCBC(textToCrypt, 16, CIV, output2)
System.DebugLog(EncodeHex(output1))
System.DebugLog(EncodeHex(output2))

i need a CBC encryption, but my output2 memoryblock is nil, what’s wrong? (output1 is taken for your sample documentation, but i don’t need it)

thanks so much

9

Don’t use AESMBS for this. CipherMBS is newer can do much more.

And since output2 is nil, it will use the input buffer. But that one is temporary since you pass a string, so your result is lost.

10

I fixed your code a bit:

Dim textToCrypt,back As String
textToCrypt =  "00023MAX010491xx" '+ uts + bic.Text + bevanda.Right(4)
Dim c As CipherMBS = CipherMBS.aes_128_cbc
Dim CKey As MemoryBlock = "4u7x!A!D*G-AwXdS"
Dim CIV As MemoryBlock = "mZf4t6w!z%C*F-Ja"

Call c.EncryptInit Ckey, CIV

Dim output1 As String = c.ProcessString(textToCrypt)
output1 = output1 + c.FinalizeAsString

Dim a As New AESMBS

Call a.SetKey(CKey, 128)
Dim output2 As New MemoryBlock(16)
Dim inputm As MemoryBlock = textToCrypt

a.EncryptCBC(textToCrypt, 16, CIV, output2)
System.DebugLog(EncodeHex(output1))
System.DebugLog(EncodeHex(output2))

which outputs:

6389BD3FA4672B660C274280CD22688B74AA2A65749A29667AC910260502CD23
6389BD3FA4672B660C274280CD22688B

so CipherMBS does padding and extended the block, while we only encrypted first block with AESMBS class.

1 Like
11

thanks @Christian_Schmitz , more clear now and it works. :smiley:
Thanks so much.

12

Oh, OK. I misunderstood your question. Sorry about that