IDX10500: Signature validation failed. Unable to resolve SecurityKeyIdentifier

Question

What might the reason be that I get the exception below when trying to validate a token.

TokenValidationParameters validationParameters = new TokenValidationParameters();

validationParameters.ValidIssuers = new List<string>() { "http://www.company.com" };

validationParameters.IssuerSigningToken = new RsaSecurityToken(
  (System.Security.Cryptography.RSACryptoServiceProvider) Certificate.Get().PublicKey.Key);

SecurityToken securityToken = null;

var claimsPrincipal = 
    (FederatedAuthentication
      .FederationConfiguration
      .IdentityConfiguration
      .SecurityTokenHandlers
      .First() as JwtSecurityTokenHandler)
      .ValidateToken(tokenString, validationParameters, out securityToken);

Error:

IDX10500: Signature validation failed. Unable to resolve SecurityKeyIdentifier: 
          'SecurityKeyIdentifier
    (
      IsReadOnly = False,
      Count = 2,
      Clause[0] = X509ThumbprintKeyIdentifierClause(
                    Hash = 0x6B7ACC520305BFDB4F7252DAEB2177CC091FAAE1),
    Clause[1] = System.IdentityModel.Tokens.NamedKeySecurityKeyIdentifierClause
    )
', 
token: '{"typ":"JWT","alg":"RS256","

Answer 1

From the error, I think you need to add an x509 Security key or credentials, something like this:

var credentials = new X509CertificateCredentials(
    Certificate.Get(),
    new SecurityKeyIdentifier(
        new NamedKeySecurityKeyIdentifierClause(
            "kid",
            "6B7ACC520305BFDB4F7252DAEB2177CC091FAAE1")));

eg this part:

new SecurityKeyIdentifier(
        new NamedKeySecurityKeyIdentifierClause(
            "kid",
            "6B7ACC520305BFDB4F7252DAEB2177CC091FAAE1")

Also, make sure your certificate is installed in your root store.