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Hash a Hex String

See more Encryption Examples

Demonstrates common pitfalls in hashing a hex string..

Note: This example requires Chilkat v9.5.0.70 or greater.

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; This example assumes the Chilkat API to have been previously unlocked.
; See Global Unlock Sample for sample code.

$oCrypt = ObjCreate("Chilkat.Crypt2")

; We have a hex string to be SHA-256 hashed:  "b08538d832bf"
; The result we expect to receive is "8a9f04cb1adfbd7f59c5918635f92f6c847e5b15f9828519d2fdbd6ead0918fc"

Local $strToHash = "b08538d832bf"

; How do we get this result?

; The 1st question to be answered is:  What bytes are getting hashed?  
; There are two possibilities:
; 1) Hash 12 bytes, namely the us-ascii values for 'b', '0', '8', '5', .... 'b', 'f'
; or
; 2) Hash 6 bytes:  0xb0, 0x85, ... 0xbf
; 

; This is how to hash the 12 us-ascii byte values:
; The Charset property defines the byte representation of the string passed to the hash algorithm:
$oCrypt.Charset = "us-ascii"
; The EncodingMode property defines the binary encoding (hex, base64, etc.) of the hash returned as an encoded string.
$oCrypt.EncodingMode = "hex"
$oCrypt.HashAlgorithm = "sha256"

Local $sHashValue = $oCrypt.HashStringENC($strToHash)
ConsoleWrite($oCrypt.LastErrorText & @CRLF)
ConsoleWrite("hash of 12 us-ascii bytes: " & $sHashValue & @CRLF)

; The result is:  327F2B33A0F0580D09840B0D7CEE54514CA33E9A  (not what we were hoping).

; -------------------------------------------
; This is how to hash the 6 bytes
; 
; "hex" is not an actual character encoding.  It's a special value to be used to tell Chilkat to hex decode
; the string and pass the decoded bytes to the hash algorithm...
; Note: This example requires Chilkat v9.5.0.70 or greater for the "hex" Charset to work properly.
$oCrypt.Charset = "hex"
; The EncodingMode and HashAlgorithm remain the same..
$sHashValue = $oCrypt.HashStringENC($strToHash)
ConsoleWrite($oCrypt.LastErrorText & @CRLF)
ConsoleWrite("hash of 6 hex bytes: " & $sHashValue & @CRLF)

; The result is 8A9F04CB1ADFBD7F59C5918635F92F6C847E5B15F9828519D2FDBD6EAD0918FC (which equals the hash we were expecting)