Online Encryption and Device Encryption is Different

[prettyfury]

I have tried encryption and decryption on ESP8266 and its working, but when trying to verify the encryption through online - https://cryptii.com/pipes/aes-encryption, the encrypted results are different. The last 16 bytes of the Encrypted data is Different, when using a 32 bytes length data. While using the 48 Bytes of Data First 32 Bytes is same as in Online AES 128 Encryption, but the Last 16 Bytes are Different.

[suculent]

Seems like difference in padding.

On 16 Jan 2020, at 11:32, prettyfury notifications@github.com wrote:

I have tried encryption and decryption on ESP8266 and its working, but when trying to verify the encryption through online - https://cryptii.com/pipes/aes-encryption https://cryptii.com/pipes/aes-encryption, the encrypted results are different. The last 16 bytes of the Encrypted data is Different, when using a 32 bytes length data. While using the 48 Bytes of Data First 32 Bytes is same as in Online AES 128 Encryption, but the Last 16 Bytes are Different.

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[suculent]

Indeed, it's the padding which is not a function on Cryptii, you need to pad with zero bytes manually to end up with correct result:

[prettyfury]

Thanks @suculent for the Information About Padding. In your new example, I have noticed the line "aesLib.set_paddingmode(paddingMode::Array);" I tried all the types of paddingMode = Array, Space, Null, Random, ZeroLength, CMS, Bit. The website cryptii.com uses CMS Padding Mode.

Password : passwordpassword Plain Text : HELLO WORLD\r IV : 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15

Password (HEX) : 70 61 73 73 77 6f 72 64 70 61 73 73 77 6f 72 64 Plain Text (HEX) : 48 45 4c 4c 4f 20 57 4f 52 4c 44 0d IV (HEX) : 00 01 02 03 04 05 06 07 08 09 0a 0b 0c 0d 0e 0f

Padding Mode :Space

Cipher Base 64: 4wr/e3Jy+1odrjvVHM8Gww== Decrypted : HELLO WORLD SUCCESS

Padding Mode :Null

Cipher Base 64: 4wr/e3Jy+1odrjvVHM8Gww== Decrypted : HELLO WORLD SUCCESS

Padding Mode : Array

Cipher Base 64: 4wr/e3Jy+1odrjvVHM8Gww== Decrypted : HELLO WORLD SUCCESS

Padding Mode : Random

Cipher Base 64: 4wr/e3Jy+1odrjvVHM8Gww== Decrypted : HELLO WORLD SUCCESS

Padding Mode : ZeroLength

Cipher Base 64: 4wr/e3Jy+1odrjvVHM8Gw4f6ofR2wwi0KtuTXo1ZJ38= Decrypted : HELLO WORLD SUCCESS

Padding Mode : CMS

Cipher Base 64: 4wr/e3Jy+1odrjvVHM8Gw3jsvPe4FAvNHP7BYMha6U8= Decrypted : HELLO WORLD SUCCESS

Padding Mode : Bit

Cipher Base 64: 4wr/e3Jy+1odrjvVHM8GwwmdxqtVqQbnAC1Phe1oVjA= Decrypted : HELLO WORLD SUCCESS

[suculent]

Thanks for finding this out. I've just updated the library with test that proves recent fixes valid.

[suculent]