public StatementValidator()
{
Include(new StatementBaseValidator());
RuleFor(x => x.Object as SubStatement)
.SetValidator(new SubStatementValidator())
.When(x => x.Object != null && x.Object.ObjectType == ObjectType.SubStatement);
// TODO: https://github.com/adlnet/xAPI-Spec/blob/master/xAPI-Data.md#requirements-14
RuleFor(x => x.Authority).SetValidator(new AgentValidator())
.When(x => x.Authority != null && x.Authority.ObjectType == ObjectType.Agent);
RuleFor(x => x.Authority)
.Must(auth =>
{
var grp = auth as Group;
return(grp.Member.Count == 2 && auth.IsAnonymous());
})
.When(x => x.Authority != null && x.Authority.ObjectType == ObjectType.Group)
.WithMessage("When 3-legged OAuth, the anonymous group must have 2 Agents. The two Agents represent an application and user together.");
RuleFor(x => x.Object.ObjectType)
.Equal(ObjectType.StatementRef)
.When(x => x.Verb?.Id == KnownVerbs.Voided)
.WithMessage("When statement verb is voided, statement object must be StatementRef.");
RuleFor(x => x).Custom((statement, context) =>
{
var attachments = statement.Attachments;
for (int i = 0; i < attachments.Count; i++)
{
var attachment = attachments.ElementAt(i);
if (attachment.UsageType == new Iri("http://adlnet.gov/expapi/attachments/signature"))
{
if (attachment.ContentType != "application/octet-stream")
{
context.AddFailure($"Attachments[{i}].ContentType", "Must be \"application/octet-stream\"");
continue;
}
var jws = JsonWebSignature.Parse(Encoding.UTF8.GetString(attachment.Payload));
if (jws.Errors.Count() > 0)
{
string key = $"Attachment[{i}].Payload";
// context.AddFailure(key, "Invalid JWS Signature.");
foreach (var error in jws.Errors)
{
context.AddFailure(key, error.Message);
}
continue;
}
string alg = jws.ProtectedHeader.Value <string>("alg");
if (!new string[] { "RS256", "RS384", "RS512" }.Contains(alg))
{
context.AddFailure($"Attachments[{i}].Pyload", "The JWS signature MUST use an algorithm of \"RS256\", \"RS384\", or \"RS512\".");
}
var jsonString = new JsonString(jws.Payload);
if (!jsonString.IsValid())
{
context.AddFailure($"Attachments[{i}].Pyload", "JWS Payload is not valid json format.");
continue;
}
var payloadStatement = new Statement(jsonString);
if (!payloadStatement.Equals(statement))
{
context.AddFailure($"Attachments[{i}].Pyload", "JWS Payload does not match the signed statement.");
}
}
}
});
}