public static void VerifyDetachedSignature()
{
string tenant = "azureadb2ctests";
string policy = "B2C_1A_SAMLAPP_demopolicy_signup_signin";
string destination = string.Format("https://{0}.b2clogin.com/{0}.onmicrosoft.com/{1}/samlp/sso/login", tenant, policy);
string relayStateInput = "1234";
string signatureAlogrithm = "SHA1";
// following can be thumbpritn or subject
string certSubject = "CN=samlsp.cpim.localhost.net, OU=AAD, C=US";
string certIdentifier = "84BDDFCC2BC9BB3B3E3AC594EBED3FDB1A49BD75";
certIdentifier = certSubject;
string samlPayLoad = "<samlp:AuthnRequest AssertionConsumerServiceURL=\"https://samltestapp2.azurewebsites.net/SP/AssertionConsumer\" Destination=\"https://login.microsoftonline.com/te/azureadb2ctests.onmicrosoft.com/B2C_1A_SAMLAPP_demopolicy_signup_signin/samlp/sso/login\" ForceAuthn=\"false\" ID=\"_1314190418\" IsPassive=\"false\" IssueInstant=\"{0}\" ProtocolBinding=\"urn:oasis:names:tc:SAML:2.0:bindings:HTTP-POST\" Version=\"2.0\" xmlns:saml=\"urn:oasis:names:tc:SAML:2.0:assertion\" xmlns:samlp=\"urn:oasis:names:tc:SAML:2.0:protocol\"> <saml:Issuer xmlns:saml=\"urn:oasis:names:tc:SAML:2.0:assertion\">https://samltestapp2.azurewebsites.net</saml:Issuer><samlp:NameIDPolicy AllowCreate=\"true\" Format=\"urn:oasis:names:tc:SAML:1.1:nameid-format:emailAddress\" SPNameQualifier=\"https://samltestapp2.azurewebsites.net\" xmlns:samlp=\"urn:oasis:names:tc:SAML:2.0:protocol\"/></samlp:AuthnRequest>";
DateTime issueInstant = DateTime.UtcNow;
samlPayLoad = string.Format(samlPayLoad, issueInstant.ToString("yyyy-MM-ddTHH:mm:ssZ"));
UrlBuilder signedRedirectUrl = SignMessage.GetSamlSignedRedirectUrl(destination, samlPayLoad, relayStateInput, signatureAlogrithm, certIdentifier);
if (VerifyRedirectSignature.IsRedirectSignatureValid(signedRedirectUrl, certIdentifier))
{
Console.WriteLine("VerifyDetachedSignature Signature is valid");
}
else
{
Console.WriteLine("VerifyDetachedSignature Signature is invalid");
}
}
internal static bool VerifyDetachedSignature(
string detachedSignature,
string detachedSignatureAlgorithm,
string signedQueryString,
string certIdentifier
)
{
if (string.IsNullOrWhiteSpace(detachedSignature))
{
throw new ArgumentException("DetachedSignature not mentioned");
}
// Check that we have a signature algorithm, if not throw error
if (string.IsNullOrWhiteSpace(detachedSignatureAlgorithm))
{
throw new ArgumentException("DetachedSignature not mentioned");
}
X509Certificate2 samlEncryptionAndSigningKey = SignMessage.GetSamlEncryptionAndSigningKey(certIdentifier);
X509Certificate2Collection publicKeys = new X509Certificate2Collection();
publicKeys.Add(samlEncryptionAndSigningKey);
object hashAlgorithmProvider = GetAlgorithmProvider(detachedSignatureAlgorithm);
try
{
// Now verify
return(IsValidDetachedSignature(
signedQueryString,
hashAlgorithmProvider,
detachedSignature,
publicKeys));
}
finally
{
IDisposable hashAlgorithmProviderDisp = hashAlgorithmProvider as IDisposable;
if (hashAlgorithmProviderDisp != null)
{
hashAlgorithmProviderDisp.Dispose();
}
}
}
/// <summary>
/// Gets SamlSigned RedirectUrl
/// </summary>
/// <param name="destination"></param>
/// <param name="samlPayLoad"></param>
/// <param name="relayStateInput"></param>
/// <param name="signatureAlogrithm"></param>
/// <param name="certSubject"></param>
/// <returns></returns>
public static UrlBuilder GetSamlSignedRedirectUrl
(
string destination,
string samlPayLoad,
string relayStateInput,
string signatureAlogrithm,
string certSubject
)
{
UrlBuilder redirectUrl = new UrlBuilder()
{
Uri = new Uri(destination)
};
// Add the request parameters to the URL builder
redirectUrl.AddOrUpdateParameter("SAMLRequest", samlPayLoad.RedirectEncode());
if (!string.IsNullOrWhiteSpace(relayStateInput))
{
redirectUrl.AddOrUpdateParameter("RelayState", relayStateInput.RedirectEncode());
}
// Save signature algorithm
SignMessage.SignatureAlgorithm sigAlgorithm = (SignMessage.SignatureAlgorithm)Enum.Parse(typeof(SignMessage.SignatureAlgorithm), signatureAlogrithm, true);
AddSignatureToRequest(redirectUrl, sigAlgorithm);
X509Certificate2 samlEncryptionAndSigningKey = SignMessage.GetSamlEncryptionAndSigningKey(certSubject);
string signature = SignMessage.SignDetached(redirectUrl.GetQueryString(), samlEncryptionAndSigningKey, sigAlgorithm);
redirectUrl.AddOrUpdateParameter("Signature", signature);
string signedSamlRedirectMessage = redirectUrl.ToString();
return(redirectUrl);
}