git-lfs/lfsapi/ntlm.go
brian m. carlson c752dcdf51
Move credential handling to its own package
In a future commit, we're going to be accessing credential handling from
multiple packages.  To avoid an import loop, move credential handling
into its own package.  Update all the callers of the credential handling
code to use a qualified name.

Where there is a local variable called "creds", which would conflict
with our package name, rename it "cred" instead.
2018-09-24 15:09:22 +00:00

141 lines
3.3 KiB
Go

package lfsapi
import (
"encoding/base64"
"fmt"
"io"
"io/ioutil"
"net/http"
"net/url"
"strings"
"github.com/git-lfs/git-lfs/creds"
"github.com/git-lfs/git-lfs/errors"
)
type ntmlCredentials struct {
domain string
username string
password string
}
func (c *Client) doWithNTLM(req *http.Request, credHelper creds.CredentialHelper, creds creds.Creds, credsURL *url.URL) (*http.Response, error) {
res, err := c.do(req, "", nil)
if err != nil && !errors.IsAuthError(err) {
return res, err
}
if res.StatusCode != 401 {
return res, nil
}
return c.ntlmReAuth(req, credHelper, creds, true)
}
// If the status is 401 then we need to re-authenticate
func (c *Client) ntlmReAuth(req *http.Request, credHelper creds.CredentialHelper, creds creds.Creds, retry bool) (*http.Response, error) {
ntmlCreds, err := ntlmGetCredentials(creds)
if err != nil {
return nil, err
}
res, err := c.ntlmAuthenticateRequest(req, ntmlCreds)
if err != nil && !errors.IsAuthError(err) {
return res, err
}
switch res.StatusCode {
case 401:
credHelper.Reject(creds)
if retry {
return c.ntlmReAuth(req, credHelper, creds, false)
}
case 403:
credHelper.Reject(creds)
default:
if res.StatusCode < 300 && res.StatusCode > 199 {
credHelper.Approve(creds)
}
}
return res, nil
}
func (c *Client) ntlmSendType1Message(req *http.Request, message []byte) (*http.Response, []byte, error) {
res, err := c.ntlmSendMessage(req, message)
if err != nil && !errors.IsAuthError(err) {
return res, nil, err
}
io.Copy(ioutil.Discard, res.Body)
res.Body.Close()
by, err := parseChallengeResponse(res)
return res, by, err
}
func (c *Client) ntlmSendType3Message(req *http.Request, authenticate []byte) (*http.Response, error) {
return c.ntlmSendMessage(req, authenticate)
}
func (c *Client) ntlmSendMessage(req *http.Request, message []byte) (*http.Response, error) {
body, err := rewoundRequestBody(req)
if err != nil {
return nil, err
}
req.Body = body
msg := base64.StdEncoding.EncodeToString(message)
req.Header.Set("Authorization", "NTLM "+msg)
return c.do(req, "", nil)
}
func parseChallengeResponse(res *http.Response) ([]byte, error) {
header := res.Header.Get("Www-Authenticate")
if len(header) < 6 {
return nil, fmt.Errorf("Invalid NTLM challenge response: %q", header)
}
//parse out the "NTLM " at the beginning of the response
challenge := header[5:]
val, err := base64.StdEncoding.DecodeString(challenge)
if err != nil {
return nil, err
}
return []byte(val), nil
}
func rewoundRequestBody(req *http.Request) (io.ReadCloser, error) {
if req.Body == nil {
return nil, nil
}
body, ok := req.Body.(ReadSeekCloser)
if !ok {
return nil, fmt.Errorf("Request body must implement io.ReadCloser and io.Seeker. Got: %T", body)
}
_, err := body.Seek(0, io.SeekStart)
return body, err
}
func ntlmGetCredentials(creds creds.Creds) (*ntmlCredentials, error) {
username := creds["username"]
password := creds["password"]
if username == "" && password == "" {
return nil, nil
}
splits := strings.Split(username, "\\")
if len(splits) != 2 {
return nil, fmt.Errorf("Your user name must be of the form DOMAIN\\user. It is currently '%s'", username)
}
domain := strings.ToUpper(splits[0])
username = splits[1]
return &ntmlCredentials{domain: domain, username: username, password: password}, nil
}