I am trying to create a sha256 signature using a RSA Private Key but I am getting a 401 "Could not authenticate in-request, auth signature : Signature verification failed: affil-product, version: 2.0.0, env: prod
I think the issue is to do whit how it get my .pem file. I have read the Microsoft documentation and the provided Walmart example. I am following this guide. I created a non password protected key pair and uploaded the public key to Walmart. I then added my consumer ID and key version to appsettings.json {"Settings": {"consumerID": "e2ca6a2f-56f2-4465-88b3-273573b1e0c9","keyVer": "4"}}.
I am then getting this data in program.cs via the following code.
IConfiguration config = new ConfigurationBuilder()
.AddJsonFile("appsettings.json")
.AddEnvironmentVariables()
.Build();
// Get values from the config given their key and their target type.
Settings settings = config.GetRequiredSection("Settings").Get<Settings>();
I then instantiate Walmart affiliate object allowing us to use the methods needed to access and read Walmart api
WalMartAfilAPI wallMartAfilAPI = new WalMartAfilAPI();
From there I Create a RSACryptoServiceProvider object and import the .pem and export the parameter.
RSACryptoServiceProvider RSAalg = new RSACryptoServiceProvider();
var rsaPem = File.ReadAllText("D:\\Users\\Adam\\source\\repos\\DealsBot\\DealsBot\\DealsBot\\wallmartAfill\\WM_IO_private_key.pem");
//now we instantiate the RSA object
var rsa = RSA.Create();
//replace the private key with our .pem
rsa.ImportFromPem(rsaPem);
//Export the key information to an RSAParameters object.
// You must pass true to export the private key for signing.
// However, you do not need to export the private key
// for verification.
RSAParameters Key = rsa.ExportParameters(true);
From here I get the time stamp and call methods from the Walmart Affiliate object.
//Get current im in unix epoch milliseconds
TimeSpan t = DateTime.UtcNow - new DateTime(1970, 1, 1);
var time = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds().ToString();
Console.WriteLine(time);
byte[] conicData = wallMartAfilAPI.Canonicalize(settings.KeyVer, settings.ConsumerID, time);
byte[] signedData = wallMartAfilAPI.HashAndSignBytes(conicData, Key);
if (wallMartAfilAPI.VerifySignedHash(conicData, signedData, Key))
{
Console.WriteLine("The data was verified");
;
Console.WriteLine(Convert.ToBase64String(signedData));
}
else
{
Here is the WalMartAfilAPI class
namespace DealsBot.wallmartAfill
{
public class WalMartAfilAPI
{
public byte[] Canonicalize(string version, string consumerId, string timestamp)
{
ASCIIEncoding ByteConverter = new ASCIIEncoding();
// Follow after the java code, which just orders the keys/values.
StringBuilder keyBuilder = new StringBuilder();
StringBuilder valueBuilder = new StringBuilder();
SortedDictionary<string, string> dictionary = new SortedDictionary<string, string>() { { "WM_CONSUMER.ID", consumerId }, { "WM_CONSUMER.INTIMESTAMP", timestamp }, { "WM_SEC.KEY_VERSION", version } };
foreach (string key in dictionary.Keys)
{
keyBuilder.Append($"{key.Trim()};");
valueBuilder.AppendLine($"{dictionary[key].Trim()}");
}
string[] conHeader = { keyBuilder.ToString(), valueBuilder.ToString() };
byte[] originalData = ByteConverter.GetBytes(conHeader[1]);
return originalData;
}
public byte[] HashAndSignBytes(byte[] DataToSign, RSAParameters Key)
{
try
{
// Create a new instance of RSACryptoServiceProvider using the
// key from RSAParameters.
RSACryptoServiceProvider RSAalg = new RSACryptoServiceProvider();
RSAalg.ImportParameters(Key);
// Hash and sign the data. Pass a new instance of SHA256
// to specify the hashing algorithm.
return RSAalg.SignData(DataToSign, SHA256.Create());
}
catch (CryptographicException e)
{
Console.WriteLine(e.Message);
return null;
}
}
public bool VerifySignedHash(byte[] DataToVerify, byte[] SignedData, RSAParameters Key)
{
try
{
// Create a new instance of RSACryptoServiceProvider using the
// key from RSAParameters.
RSACryptoServiceProvider RSAalg = new RSACryptoServiceProvider();
RSAalg.ImportParameters(Key);
// Verify the data using the signature. Pass a new instance of SHA256
// to specify the hashing algorithm.
return RSAalg.VerifyData(DataToVerify, SHA256.Create(), SignedData);
}
catch (CryptographicException e)
{
Console.WriteLine(e.Message);
return false;
}
}
}
}
