r.ParseForm字段顺序

Question

So I would like to preserve the order of the post fields. But now using the http ParseForm function it will put the fields into a map which will have a different order each time.

The original query : a=1&b=2&c=3 can become b=2&c=3&a=1 or any random order.

Since I hash the query and compare it with the hash of the user his query the hash on my side changes all the time since the order of the fields are random.

Code:

func parsePostQuery(r *http.Request, hashQuery string) bool {
    urlquery := url.Values{}

    r.ParseForm()

    for k, p := range r.Form {
        urlquery.Set(k, p[0])
    }

    //some psuedo code
    if hashQuery == hash(urlquery.Encode()){
        return true
    }

    return false
}

How can I parse the fields that are submitted by the user and keep the field order of the user?

Sidenote: I do not know the field names in advance.

Answer 1

In the same area as other answers, you will need the clients to calculate their hash by alphabetizing all parameters before hashing. The code you've supplied should work fine; values.Encode() will sort the values by key on it's own:

Encode encodes the values into “URL encoded” form ("bar=baz&foo=quux") sorted by key.

There's no way to preserve the ordering of the client; in fact, what you receive may not even be how it was ordered on the client end. However unlikely, there's no guarantee that intermediate processes won't change things.