2.3.7.3 Binary Document XOR Data Transformation Method 1

Data transformed by Binary Document XOR Data Transformation Method 1 for encryption MUST be as specified in the EncryptData_Method1 procedure. This procedure takes the following parameters:

• Password: An ASCII string that specifies the password to be used to encrypt the data.

• Data: An array of unsigned 8-bit integers that specifies the data to be encrypted.

• XorArrayIndex: An unsigned integer that specifies the initial index into the XOR obfuscation array to be used.

   FUNCTION EncryptData_Method1
       PARAMETERS Password, Data, XorArrayIndex
       DECLARE XorArray as array of 8-bit unsigned integers
    
       SET XorArray TO CreateXorArray_Method1(Password)
    
       FOR Index FROM 0 TO Data.Length
           SET Value TO Data[Index]
           SET Value TO (Value rotate left 5 bits)
           SET Value TO Value BITWISE XOR XorArray[XorArrayIndex]
           SET DATA[Index] TO Value
    
           INCREMENT XorArrayIndex
           SET XorArrayIndex TO XorArrayIndex MODULO 16
       END FOR
   END FUNCTION
  

Data transformed by the Binary Document XOR Data Transformation Method 1 for decryption MUST be as specified in the DecryptData_Method1 procedure. This procedure takes the following parameters:

• Password: An ASCII string that specifies the password to be used to decrypt the data.

• Data: An array of unsigned 8-bit integers that  specifies the data to be decrypted.

• XorArrayIndex: An unsigned integer that specifies the initial index into the XOR obfuscation array to be used.

   FUNCTION DecryptData_Method1
       PARAMETERS Password, Data, XorArrayIndex
       DECLARE XorArray as array of 8-bit unsigned integers
    
       SET XorArray TO CreateXorArray_Method1(Password)
    
       FOR Index FROM 0 to Data.Length
           SET Value TO Data[Index]
           SET Value TO Value BITWISE XOR XorArray[XorArrayIndex]
           SET Value TO (Value rotate right 5 bits)
           SET Data[Index] TO Value
    
           INCREMENT XorArrayIndex
           SET XorArrayIndex TO XorArrayIndex MODULO 16
       END FOR
   END FUNCTION