Xceed Encryption Library Documentation
Hashing a file (VB streaming example)
Examples > Hashing a file (VB streaming example)
Visual Basic Copy Code

' This example hashes data using the SHA method from a file to memory in 8K (8192 byte) chunks. 

Const CHUNKSIZE = 8192Dim xHash As New XceedHashing
Call xHash.License( "your license key" ) 

Dim lOffSet As Long
Dim lFileSize As Long
Dim lBytesRead As Long
Dim vaHash As Variant 

Set xHash.HashingMethod = New XceedSHAHashingMethod 

lOffSet = 0 ' We must track the current offset 

On Error Resume Next

xHash.HashingMethod.HashSize = 256
lFileSize = FileLen("c:\temp\source.txt") 

While lOffSet < lFileSize
  'bEndOfData will be true if the current offset + CHUNKSIZE exceeds the end of the file. 
  lBytesRead = xHash.ReadFile("c:\temp\source.txt", lOffSet, CHUNKSIZE, efpHash, _
                              (lOffSet + CHUNKSIZE >= lFileSize))  

  lOffSet = lOffSet + lBytesRead 
Wend 

If Err.Number = 0 Then
  MsgBox "Finished Hashing file to memory." 
  vaHash = xHash.HashingMethod.HashValue 
  ' Do something with the hash value... 
Else
  MsgBox Err.Number & " " & Err.Description 
End If

On Error Goto 0 

Set xHash = Nothing