B4X Requires Chilkat v11.0.0+

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

See more RSA Examples

Demonstrates how to generate a signature for a Walmart Partner REST API call. B4X

Dim success As Boolean = False

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

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

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

'  Build the string to sign.
Dim sbStringToSign As ChilkatStringBuilder
sbStringToSign.Initialize
sbStringToSign.Append(consumerId)
sbStringToSign.Append(Chr(10))
sbStringToSign.Append(baseUrl)
sbStringToSign.Append(Chr(10))
sbStringToSign.Append(httpMethod)
sbStringToSign.Append(Chr(10))
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).
sbStringToSign.Append("000" & Chr(10))

Dim privKey As ChilkatPrivateKey
privKey.Initialize("privKey")
'  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 = False Then
    Log(privKey.LastErrorText)
    Return
End If


Dim rsa As ChilkatRsa
rsa.Initialize
success = rsa.UsePrivateKey(privKey)
If success = False Then
    Log(rsa.LastErrorText)
    Return
End If


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

Dim signatureString As String = rsa.SignStringENC(sbStringToSign.GetAsString, "SHA256")
If rsa.LastMethodSuccess = False Then
    Log(rsa.LastErrorText)
    Return
End If


Log("Signature String: " & signatureString)