Various HMAC_SHA256 functions in classic ASP gives different results - php

Question

Somehow I need to generate a hash in Classic ASP which is equivalent to PHP's following function's output:
$hash = hash_hmac('SHA256', $message, pack('H*', $secret));
where $message = 'stackoverflow'; $secret = '1234567890ABCDEF';. I tried quite a lot approaches online, but none matches the PHP result:
bcb3452cd48c0f9048e64258ca24d0f3399563971d4a5dcdc531a7806b059e36
Method 1: Using dvim_brix_crypto-js-master_VB.asp online (using CrytoJS)
Function mac256(ent, key)
Dim encWA
Set encWA = ConvertUtf8StrToWordArray(ent)
Dim keyWA
Set keyWA = ConvertUtf8StrToWordArray(key)
Dim resWA
Set resWA = CryptoJS.HmacSHA256(encWA, key)
Set mac256 = resWA
End Function
Function ConvertUtf8StrToWordArray(data)
If (typename(data) = "String") Then
Set ConvertUtf8StrToWordArray = CryptoJS.enc.Utf8.parse(data)
Elseif (typename(data) = "JScriptTypeInfo") Then
On error resume next
'Set ConvertUtf8StrToWordArray = CryptoJS.enc.Utf8.parse(data.toString(CryptoJS.enc.Utf8))
Set ConvertUtf8StrToWordArray = CryptoJS.lib.WordArray.create().concat(data) 'Just assert that data is WordArray
If Err.number>0 Then
Set ConvertUtf8StrToWordArray = Nothing
End if
On error goto 0
Else
Set ConvertUtf8StrToWordArray = Nothing
End if
End Function
The script can be found here. This method gives:
c8375cf0c0db721ecc9c9b3a034284117d778ee8594285196c41d5020917f78c
Method 2: Pure Classic ASP Approach
Public Function HMAC_SHA256(prmKey, prmData)
Dim theKey : theKey = prmKey
Dim Block_Size, O_Pad, I_Pad
Block_Size = 64
O_Pad = 92 'HEX: 5c'
I_Pad = 54 'HEX: 36'
Dim iter, iter2
If Len(theKey) < Block_Size Then
For iter = 1 to Block_Size - Len(theKey)
theKey = theKey & chr(0)
Next
ElseIf Len(theKey) > Block_Size Then
theKey = SHA256(theKey)
End If
Dim o_key_pad : o_key_pad = ""
Dim i_key_pad : i_key_pad = ""
For iter = 1 to Block_Size
o_key_pad = o_key_pad & Chr(Asc(Mid(theKey,iter,1)) xor O_Pad)
i_key_pad = i_key_pad & Chr(Asc(Mid(theKey,iter,1)) xor I_Pad)
Next
HMAC_SHA256 = SHA256(o_key_pad & SHA256(i_key_pad & prmData))
End Function
result = HMAC_SHA256(secret, message)
This method gives:
bc0511316791176484c7d80bc8faaecd8388b75fb97516181ba6b361fd032531
Method 3: Using Amazon AWS's sha256.wsc (using CrytoJS)
Dim sha
Set sha = GetObject( "script:" & Server.MapPath("sha256.wsc") )
sha.hexcase = 0
result = sha.b64_hmac_sha256(secret, message)
The WSC can be found here. This method gives (same result as Method 1):
c8375cf0c0db721ecc9c9b3a034284117d778ee8594285196c41d5020917f78c
I think the problem is the pack() part, which changes the Hex string to binary. Therefore, I found a way to reproduce the pack() function in ASP:
Dim key2, hexarr, binstr
key2 = "12 34 56 78 90 AB CD EF"
hexarr = Split(key2)
ReDim binarr(UBound(hexarr))
For i = 0 To UBound(hexarr)
binarr(i) = Chr(CInt("&h" & hexarr(i)))
Next
binstr = Join(binarr, "")
where the key2 is the original secret with space added in every 2 characters. By replacing the secret with binstr, the methods now produce:
Method 1: 8ab9e595eab259acb10aa18df7fdf0ecc5ec593f97572d3a4e09f05fdd3aeb8f
Method 2: d23fcafb41d7b581fdae8c2a4a65bc3b19276a4bd367eda9e8e3de43b6a4d355
Method 3: 8ab9e595eab259acb10aa18df7fdf0ecc5ec593f97572d3a4e09f05fdd3aeb8f
None of the above results is identical to PHP's one. What did I miss now?

Answer 1

Check out the following example.
The only requirement with this approach is Microsoft .Net Framework 2.0 (preinstalled starting from Windows Server 2003 R2) to use Com Interops.
I tried to be descriptive in the comments but feel free to ask questions about it.
'Returns Byte(), UTF-8 bytes of unicode string
Function Utf8Bytes(text)
With Server.CreateObject("System.Text.UTF8Encoding")
Utf8Bytes = .GetBytes_4(text)
End With
End Function
'Returns String, sequential hexadecimal digits per byte
'data As Byte()
Function BinToHex(data)
With Server.CreateObject("MSXML2.DomDocument").CreateElement("b64")
.dataType = "bin.hex"
.nodeTypedValue = data
BinToHex = .text
End With
End Function
'Returns Byte(), a keyed hash generated using SHA256 method
'data As String, key As Byte()
Function HashHmacSha256(data, key)
With Server.CreateObject("System.Security.Cryptography.HMACSHA256")
.Key = key
HashHmacSha256 = .ComputeHash_2(UTF8Bytes(data))
End With
End Function
'Returns Byte(), of a packed hexadecimal string
'instead of PHP's pack('H*'
Function HexToBin(data)
With Server.CreateObject("MSXML2.DomDocument").CreateElement("b64")
.dataType = "bin.hex"
.text = data
HexToBin = .nodeTypedValue
End With
End Function
packed_secret = HexToBin("1234567890ABCDEF")
message = "stackoverflow"
binary_hash = HashHmacSha256(message, packed_secret)
string_hash = BinToHex(binary_hash)
Response.Write string_hash