(Classic ASP) Walmart Partner API Authentication (Generate a Signature for a Request)

Demonstrates how to generate a signature for a Walmart Partner REST API call.

Chilkat ActiveX Downloads

ActiveX for 32-bit and 64-bit Windows

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

consumerId = "b68d2a72...."
baseUrl = "https://marketplace.walmartapis.com/v2/feeds"
' This is your Base64 encoded private key
privateEncodedStr = "MIICeAIBADANBgkqhkiG9w0BAQEFAA......"
httpMethod = "GET"

' We need a timestamp in decimal string form representing the number of milliseconds since Jan 01 1970 UTC.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.CkDateTime")
set dt = Server.CreateObject("Chilkat.CkDateTime")
' Set bLocal = 1 for a timestamp in the local timezone.  Set bLocal = 0 for a UTC timestamp.
bLocal = 0
' This gets the timestamp in seconds, not milliseconds.
timeStampVal = dt.GetAsUnixTime(bLocal)

' Build the string to sign.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.StringBuilder")
set sbStringToSign = Server.CreateObject("Chilkat.StringBuilder")
success = sbStringToSign.Append(consumerId)
success = sbStringToSign.Append(vbLf)
success = sbStringToSign.Append(baseUrl)
success = sbStringToSign.Append(vbLf)
success = sbStringToSign.Append(httpMethod)
success = sbStringToSign.Append(vbLf)
success = sbStringToSign.AppendInt(timeStampVal)
' We add three zero's so that the timestamp value is in milliseconds.
' We don't care about accuracy down to less than a second.
' All the server cares about is that the request was signed at the current date/time
' within some reasonable margin of error (to account for systems having clocks
' that may be slightly different).
success = sbStringToSign.Append("000" & vbLf)

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.PrivateKey")
set privKey = Server.CreateObject("Chilkat.PrivateKey")
' Load the private key into a private key object.
' Note: Technically the private key is not PEM because it lacks the header/footer strings
' used for PEM.  However, the LoadPem method will still accept it and load it correctly.
success = privKey.LoadPem(privateEncodedStr)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( privKey.LastErrorText) & "</pre>"
    Response.End
End If

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.Rsa")
set rsa = Server.CreateObject("Chilkat.Rsa")
success = rsa.ImportPrivateKeyObj(privKey)
If (success <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rsa.LastErrorText) & "</pre>"
    Response.End
End If

' We want a base64 signature string.
rsa.EncodingMode = "base64"

signatureString = rsa.SignStringENC(sbStringToSign.GetAsString(),"SHA256")
If (rsa.LastMethodSuccess <> 1) Then
    Response.Write "<pre>" & Server.HTMLEncode( rsa.LastErrorText) & "</pre>"
    Response.End
End If

Response.Write "<pre>" & Server.HTMLEncode( "Signature String: " & signatureString) & "</pre>"

%>
</body>
</html>