I'm trying to use AES on the Android side, for a simple example, here's my encryption block
The "USER_IV!6" is a 16-byte string constant as is the "USER_KEY" (differing values).
Encrypting a test value (such as "[email protected]") produces a 64-byte HEX string as expected. Using this same basic methodology in a VS-2017 VB.NET application, when I encrypt the same string using the same IV and KeyGen I come up with an entirely different 64-byte HEX string. My vb.net code:
I have verified IV and KEY values are exactly the same between apps. Is this related to the "bouncy castle" issues in newer Android versions? I thought that only affected DES/3DES?
Also, the specs on this project prohibit me from creating a B4J back-end I could call from the VB.NET app to decode it for me. Is there any way to encrypt/decrypt with B4A on the newer Android versions and have it decrypted/encrypted properly by a Windows platform application?
B4X:
Public Sub AES_Encrypt(DataToEncrypt As String) As String
Dim poKG As KeyGenerator
Dim poCy As Cipher
Dim poBC As ByteConverter
Dim poData() As Byte
' doing AES
poCy.Initialize("AES")
' set InitializationVector value
poCy.InitialisationVector = poBC.StringToBytes(USER_IV16, "utf8")
' Generate a key
poKG.Initialize("AES")
poKG.KeyFromBytes(poBC.StringToBytes(USER_KEY, "utf8"))
' encrypt the string into a byte array
poData = poCy.Encrypt(poBC.StringToBytes(DataToEncrypt, "utf8"), poKG.Key, True)
' convert the byte array to a HEX string and return it
Return poBC.HexFromBytes(poData)
End SubEncrypting a test value (such as "[email protected]") produces a 64-byte HEX string as expected. Using this same basic methodology in a VS-2017 VB.NET application, when I encrypt the same string using the same IV and KeyGen I come up with an entirely different 64-byte HEX string. My vb.net code:
B4X:
Public Shared Function AESEncrypt(ByVal PlainText As String) As String
Dim pyBytes() As Byte
Dim pyResult() As Byte
Dim piIndex As Integer
Dim poResult As New System.Text.StringBuilder
pyBytes = System.Text.UTF8Encoding.UTF8.GetBytes(PlainText)
' Encrypt it
Dim poAES As New System.Security.Cryptography.AesManaged
poAES.IV = System.Text.UTF8Encoding.UTF8.GetBytes(USER_IV16)
poAES.Key = System.Text.UTF8Encoding.UTF8.GetBytes(USER_KEY)
pyResult = poAES.CreateEncryptor().TransformFinalBlock(pyBytes, 0, pyBytes.Length)
' convert it to a HEX string
For piIndex = 0 To pyResult.Length - 1
poResult.Append(pyResult(piIndex).ToString("X2"))
Next
Return poResult.ToString
End FunctionAlso, the specs on this project prohibit me from creating a B4J back-end I could call from the VB.NET app to decode it for me. Is there any way to encrypt/decrypt with B4A on the newer Android versions and have it decrypted/encrypted properly by a Windows platform application?
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