authenticated http client requests from golang

Question

I have the following code:

client := &http.Client{}

/* Authenticate */
req, err := http.NewRequest("GET", "http://164.99.113.32/Authenticate", nil)
req.SetBasicAuth("<username>","<password>")
resp, err := client.Do(req)
if err != nil {
    fmt.Printf("Error : %s", err)
}

/* Get Details */
req.URL, _ = url.Parse("http://164.99.113.32/Details")
resp, err = client.Do(req)
if err != nil {
    fmt.Printf("Error : %s", err)
}

Now, the second http call is failing with a 401 access-denied error. A different REST client (a firefox plugin) correctly gets the details from the server, so I know that nothing is wrong on the server side. Do I need to pass some kind of session string or something that we got in the previous request ?

score 25 · Accepted Answer · answered Jul 06 '12 at 13:55

Okay. I have resolved this. I just needed to create a cookie jar.

I am surprised that this is not handled by default by the golang http req/client class.

The code that I had to use was:

type myjar struct {
    jar map[string] []*http.Cookie
}

func (p* myjar) SetCookies(u *url.URL, cookies []*http.Cookie) {
    fmt.Printf("The URL is : %s\n", u.String())
    fmt.Printf("The cookie being set is : %s\n", cookies)
    p.jar [u.Host] = cookies
}

func (p *myjar) Cookies(u *url.URL) []*http.Cookie {
    fmt.Printf("The URL is : %s\n", u.String())
    fmt.Printf("Cookie being returned is : %s\n", p.jar[u.Host])
    return p.jar[u.Host]
}

and then in main:

    jar := &myjar{}
    jar.jar = make(map[string] []*http.Cookie)
    client.Jar = jar

Works.

score 14 · Answer 2 · answered Jul 06 '12 at 13:37

14

With HTTP Basic Authentication, the credentials are required for every request. Try copying the

req.SetBasicAuth("<username>", "<password>")

line before the second client.Do(req).

The reason the Firefox plugin gets the details is that the browser will cache HTTP Basic Authentication tokens for subsequent use.

answered Jul 06 '12 at 13:37

Mike Reedell

1,567
15
23

Is that method validates whether password is correct? In my case it fails silently when I passed incorrect password. – laimison Jan 02 '19 at 10:18
I can answer to my own question. This can be solved with `resp, err = client.Do(req)` `defer resp.Body.close()` and `if resp.StatusCode != 200 { log.Fatal("HTTP response code is not 200") }`. So it's possible to track the response using this method. – laimison Jan 02 '19 at 10:31

score 4 · Answer 3 · edited May 23 '17 at 12:00

4

There is a new official library, maybe this is helpful.

http://golang.org/pkg/net/http/cookiejar/

example: Golang: how to follow location with cookie

edited May 23 '17 at 12:00

Community

1
1

answered Jul 21 '14 at 02:23

Daniel YC Lin

15,050
18
63
96

authenticated http client requests from golang

3 Answers3

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