/Util/AES/AESMBS example
Feedback.

Function:
You find this example project in your Plugins Download as a Realbasic project file within the examples folder: /Util/AES/AESMBS example
This example is the version from Fri, 14th May 2009.
Notes: Last modified: Fri, 14th May 2009

Class Window1
Inherits Window
  // Controls
  ControlInstance
  End ControlInstance
  ControlInstance
  End ControlInstance
  ControlInstance
  End ControlInstance
  ControlInstance
  End ControlInstance
  ControlInstance
  End ControlInstance
  ControlInstance
  End ControlInstance
  ControlInstance
  End ControlInstance
  ControlInstance
  End ControlInstance
  ControlInstance
    Sub Action() Handles Event
      dim temp as string
      
      temp=EditField2.text
      temp=DefineEncoding(temp,Encodings.ASCII)
      EditField3.text=encryptAES(temp, EditField1.text) // data, key
      
      
      temp=decryptAES(EditField3.text, EditField1.text) // data, key
      temp=DefineEncoding(temp,Encodings.UTF8)
      EditField4.text=temp
    End Sub
  End ControlInstance
  
  // Properties
  Dim aESpreviousCipherText As string
  
  // Methods
  Function decryptAES(data as string, key as string) As String
    dim temp as string
    dim pad as integer
    
    aESpreviousCipherText = ""
    
    temp = decrypt_AES128(data, key)
    
    //padding
    pad=asc(right(temp,1))
    if pad<16 then
      temp=mid(temp,1,len(temp)-pad)
    end if
    //
    
    return temp
  End Function
  Function decrypt_AES128(data as string, key as string) As String
    dim d as string
    dim temp as string
    dim toDecrypt as string
    dim output as string
    dim t1, t2, t as integer
    dim s as string
    dim i, n,j as integer
    
    d=decodeBase64MBS(data)
    
    n=Ceil(lenB(d)/16)
    
    for i=1 to n
      
      toDecrypt = mid(d, 1+16*(i-1), 16)
      
      temp=decrypt_AES128_16bytes(toDecrypt, key )
      
      
      //In the cipher-block chaining (CBC) mode, each block of plaintext
      // is XORed with the previous ciphertext block before being encrypted.
      if i>1 then
        
        s=""
        for j=1 to 16
          t1=asc(mid(temp,j,1))
          t2=asc(mid(AESpreviousCipherText,j,1))
          T=bitwise.bitXor(t1,t2) //XOR
          s=s+CHR(t)
        next
        temp=s
        
      end if
      //-----------------------------------------------------------------------------------
      
      
      aESpreviousCipherText = toDecrypt
      output=output+temp
    next
    
    return output
    
  End Function
  Function decrypt_AES128_16bytes(data as string, key as string) As String
    dim a as AESMBS
    dim mbKey as MemoryBlock
    dim mbData as MemoryBlock
    
    mbKey=NewMemoryBlock(20)
    mbKey.CString(0)=key // 16 byte key for 128bit
    
    a=new AESMBS
    
    
    if a.SetKey(mbKey, 128) then
      
      mbData=NewMemoryBlock(16)
      mbData.StringValue(0,16)=data
      a.Decrypt(mbData)
      
      return mbData.StringValue(0,16)
      
    end if
    
  End Function
  Function encryptAES(data as string, key as string) As String
    dim temp as string
    
    aESpreviousCipherText = ""
    
    temp = encrypt_AES128(data, key)
    
    return temp
  End Function
  Function encrypt_AES128(data as string, key as string) As String
    dim temp as string
    dim output as string
    dim toEncrypt as string
    dim t1, t2, t as integer
    dim s as string
    dim i, n,j as integer
    
    n=Ceil(lenB(data)/16)
    
    for i=1 to n
      
      toEncrypt =  mid(data, 1+16*(i-1), 16)
      
      //In the cipher-block chaining (CBC) mode, each block of plaintext
      // is XORed with the previous ciphertext block before being encrypted.
      if AESpreviousCipherText>"" then
        
        s=""
        for j=1 to 16
          t1=asc(mid(toEncrypt,j,1))
          t2=asc(mid(AESpreviousCipherText,j,1))
          T=bitwise.bitXor(t1,t2) //XOR
          s=s+CHR(t)
        next
        toEncrypt=s
        
      end if
      //-----------------------------------------------------------------------------------
      
      temp=encrypt_AES128_16bytes(toEncrypt, key )
      AESpreviousCipherText = temp
      
      output=output+temp
    next
    
    
    
    
    output=encodeBase64MBS(output,0,"")
    
    
    return output
    
  End Function
  Function encrypt_AES128_16bytes(data as string, key as string) As String
    dim a as AESMBS
    dim mbKey as MemoryBlock
    dim mbdata as MemoryBlock
    dim l,ll as integer
    dim toEncrypt as string
    dim padding as integer
    dim i as integer
    
    l=lenB(data)
    padding = l mod 16
    
    //Pad the input with a padding string of between 1 and 15 bytes to make the total length an exact multiple of 16 bytes.
    //The value of each byte of the padding string is set to the number of bytes added - i.e. 8 bytes of value 0x08,
    //7 bytes of value 0x07, ..., 2 bytes of 0x02, or one byte of value 0x01.
    
    padding=16-padding  //padding
    if padding=16 then
      padding=0
    end if
    
    ll=l+padding
    toEncrypt =data
    
    if padding>0 then
      for i=1 to padding
        toEncrypt=toEncrypt+CHR(padding)
      next
    end if
    
    
    mbKey=NewMemoryBlock(20)
    mbKey.CString(0)=key // 16 byte key for 128bit
    
    
    a=new AESMBS
    
    if a.SetKey(mbKey, 128) then
      mbdata=NewMemoryBlock(16)
      mbData.StringValue(0,16)=toEncrypt
      
      a.Encrypt(mbdata)
      
      return mbData.StringValue(0,16)
      
    end if
    
    
    
  End Function
End Class

Class App
Inherits Application
End Class