Crypto AES256 v4.3.2.1 D11 encryption Key 256 CBC is not compatible with v4.3.0.4 AES encryption

VCL TMS Cryptography Pack
1

Hi,

Im migrating my 10.4.2 app to D11, so i downloaded current v4.3.2.1 TMS crypto version.

The problem is that the encrypted data made with v4.3.0.4 is not compatible with v4.3.2.1. Im getting this error:

Project app.apk raised exception class ECryptoPack with message 'error : in AES, the cipher text cannot be decrypted because the padding is not correct!

Would like support with this case, because now i have an encrypted database that my app cant read.

2

Hi Aldo,
I would need more details to look at this. Can you provide a some code?
bernard

3

Hi Bernard,

var
aesencriptar : TAESEncryption;
test : string;
ENCRYPTED_TEXT : string;
begin

aesencriptar := TAESEncryption.Create(self);
aesencriptar.AType := atCBC;
aesencriptar.keyLength := kl256;
aesencriptar.paddingMode := TPaddingMode.PKCS7;

aesencriptar.IV := '2jsffm394SFFmsa';
aesencriptar.key := 'n@#msd9fkfsakfas1SAcm39nFA032ds' ;

test := aesencriptar.decrypt(ENCRYPTED_TEXT);

//ENCRYPTED_TEXT comes form the database;
end;

Any more info, just please let me kwow.

Thanks!

Regards,
Aldo Victoria

4

Hi Aldo,
Your IV only has 15 characters:
aesencriptar.IV := '2jsf fm39 4SFF msa'; <= the last group has 3 letters only (or you need a conversion)
And the key only has 31 characters:
aesencriptar.key := 'n@#m sd9f kfsa kfas 1SAc m39n FA03 2ds' ;

Regards,
bernard

5

Hi Bernard,

Sorry, you are right. Now correct my example

var
aesencriptar : TAESEncryption;
test : string;
ENCRYPTED_TEXT : string;
begin

aesencriptar := TAESEncryption.Create(self);
aesencriptar.AType := atCBC;
aesencriptar.keyLength := kl256;
aesencriptar.paddingMode := TPaddingMode.PKCS7;

aesencriptar.IV := '2jsrbQ394SPFmsaL';
aesencriptar.key := 'n@#msd9fkfOakfas1SQ!@cm39nFA032d' ;

test := aesencriptar.decrypt(ENCRYPTED_TEXT);

//ENCRYPTED_TEXT comes form the database;
end;

6

Hi Aldo,
That's better. Can you provide a sample of the ENCRYPTED_TEXT?
Regards,
bernard

7

Hi Bernard,

Created this example:

aesencriptar := TAESEncryption.Create(self);
aesencriptar.AType := atCBC;
aesencriptar.keyLength := kl256;
aesencriptar.paddingMode := TPaddingMode.PKCS7;

aesencriptar.IV := 'DGUpltToscainLee';
aesencriptar.key := 'DGursoSTClnPyAleQryAlertasSinLee' ;

test := aesencriptar.decrypt('5A7579B3ABA3D60BED7EC626FA8ED7E0013DB4EC6FD0D126B2684231AC89502E4D65A5CF45E3BFFF54EE18A62F1A3AFE');

Any more info, just please let me know.

You can do a test encrypting with v4.3.0.4 using this key/IV
IV := 'DGUpltToscainLee';
key := 'DGursoSTClnPyAleQryAlertasSinLee' or any another key/IV and it wont decrypt with v4.3.2.1 using the same Key/IV

8

Hi Aldo,

What is is original size of the string you have encrypted?

Regards,

bernard

9

Hi Bernard,

Original text size 19 characters.

10

If somehow it can help. I have tested on Delphi 10.4.2 and is working the encryption / decryption with AES and is compatible with TMS Crypto v4.3.0.4 and v4.3.2.1.

The problem is only with Delphi 11.

11

Aldo,
Thanks, I have noticed the same thing and that's why I am bit 'lost' as there is no change in the AES code whatsoever between these versions.

12

Hi Bernard,

Hope that you are doing fine.

Could you give me any update about this issue?

13

Hi Aldo,

It looks like either the key or the IV (or both) is wrong or incorrectly converted.

I have tried to decrypt with the original C primitives (AES_DecryptString / AES_DecryptBinaryBuffer) and get the same error.

I don't see where the problem lies at this stage.

Does the original code convert anything?

Regards,

bernard

14

Aldo,

To be on the safe side I rerun the tests from NIST Special Publication 800-38A (Recommendation for Block Cipher Modes of Operation) and all of them passed for the ECB 256 and CBC 256 modes and key size in RAD Studio 11. Which brings even more confusion and most likely locates the problem in a conversion operation or similar.

Regards,

bernard

15

Hi Bernard,

Does the original code convert anything? Yes. Is working fine on Delphi 10.4.2 the AES256 encrypt/decrypt of the database but when i compile on D11 it gives the error Project app.apk raised exception class ECryptoPack with message 'error : in AES, the cipher text cannot be decrypted because the padding is not correct!

Thanks.

16

Hi Aldo,
Could you you send me the v4.3.0.4 AESObj.pas, MiscObj.pas (in the main TMS CP directory) and aes.obj and aes_mode.obj (in the libWin32 folder), together with a cleartext/cryptogram pair and the IV and key for this pair?

bernard@tmssoftware.com

Thanks,
bernard

17

Hi Bernard,

Unfortunately i uninstalled version v4.3.0.4 and i cant find the installation file.

Send the example pair and key, with encrypted and plain text to your email.

Thanks!

Regards,
Aldo Victoria

18

Hi Bernard,

Hope that you are doing fine by there.

Any news about this bug ?

Thanks!

19

To All Readers of this thread,

Here is the closure on this report.

There is no bug in the AES library, the issue was with Delphi 11 (and I could not reproduce it with my version) and was fixed with the release of patch #1.

Bernard

20

Thanks a lot for the great support Bernard!