(Xojo Plugin) Walmart Partner API Authentication (Generate a Signature for a Request)

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

Chilkat Xojo Plugin Download Xojo Plugin for Windows, Linux, Mac OS X, and ARM, ARM64

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

Dim success As Boolean

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

// We need a timestamp in decimal string form representing the number of milliseconds since Jan 01 1970 UTC.
Dim dt As New Chilkat.CkDateTime
// Set bLocal = True for a timestamp in the local timezone.  Set bLocal = False for a UTC timestamp.
Dim bLocal As Boolean
bLocal = False
// This gets the timestamp in seconds, not milliseconds.
Dim timeStampVal As Int32
timeStampVal = dt.GetAsUnixTime(bLocal)

// Build the string to sign.
Dim sbStringToSign As New Chilkat.StringBuilder
success = sbStringToSign.Append(consumerId)
success = sbStringToSign.Append(EndOfLine.Unix)
success = sbStringToSign.Append(baseUrl)
success = sbStringToSign.Append(EndOfLine.Unix)
success = sbStringToSign.Append(httpMethod)
success = sbStringToSign.Append(EndOfLine.Unix)
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" + EndOfLine.Unix)

Dim privKey As New 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 <> True) Then
    System.DebugLog(privKey.LastErrorText)
    Return
End If

Dim rsa As New Chilkat.Rsa
success = rsa.ImportPrivateKeyObj(privKey)
If (success <> True) Then
    System.DebugLog(rsa.LastErrorText)
    Return
End If

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

Dim signatureString As String
signatureString = rsa.SignStringENC(sbStringToSign.GetAsString(),"SHA256")
If (rsa.LastMethodSuccess <> True) Then
    System.DebugLog(rsa.LastErrorText)
    Return
End If

System.DebugLog("Signature String: " + signatureString)