return
	}

	sessionPolicyStr := r.Form.Get(stsPolicy)
	// https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html
	// The plain text that you use for both inline and managed session
	// policies shouldn't exceed 2048 characters.
	if len(sessionPolicyStr) > 2048 {
		writeSTSErrorResponse(ctx, w, ErrSTSInvalidParameterValue, errSessionPolicyTooLarge)