(Chilkat2-Python) Walmart Partner API Authentication (Generate a Signature for a Request)

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

Chilkat2 Python Downloads install with pip pip3 install chilkat2 or download... Python Module for Windows, Linux, Alpine Linux, MacOS, Solaris

import sys
import chilkat2

# 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.
dt = chilkat2.CkDateTime()
# Set bLocal = True for a timestamp in the local timezone.  Set bLocal = False for a UTC timestamp.
bLocal = False
# This gets the timestamp in seconds, not milliseconds.
timeStampVal = dt.GetAsUnixTime(bLocal)

# Build the string to sign.
sbStringToSign = chilkat2.StringBuilder()
sbStringToSign.Append(consumerId)
sbStringToSign.Append("\n")
sbStringToSign.Append(baseUrl)
sbStringToSign.Append("\n")
sbStringToSign.Append(httpMethod)
sbStringToSign.Append("\n")
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\n")

privKey = chilkat2.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):
    print(privKey.LastErrorText)
    sys.exit()

rsa = chilkat2.Rsa()
success = rsa.ImportPrivateKeyObj(privKey)
if (success != True):
    print(rsa.LastErrorText)
    sys.exit()

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

signatureString = rsa.SignStringENC(sbStringToSign.GetAsString(),"SHA256")
if (rsa.LastMethodSuccess != True):
    print(rsa.LastErrorText)
    sys.exit()

print("Signature String: " + signatureString)