There's a bug in the trading api where if you send the "key" and "sign" header-fields in lowercase, the server would erroneously reject it with "Invalid API key". This is a bug because according to
rfc2068, first paragraph under section 4.2 Message Headers:
...Each header field consists of a name followed by a colon (":") and the field value. Field names are case-insensitive...
I noticed this problem when I was writing a query api using the luasockets+luasec library. This causes a problem because that library lower-cases the header field names prior to sending the POST request out.
Yes, field names should be case-insensitive, but your quote says nothing about field
values. Is what you're saying is that you passed in a value in an case insensitive way, and you think this is wrong?