/usr/share/gocode/src/github.com/abbot/go-http-auth/basic.go is in golang-github-abbot-go-http-auth-dev 0.0~git20150714.0.46b9627-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 | package auth
import (
"crypto/sha1"
"crypto/subtle"
"encoding/base64"
"net/http"
"strings"
)
type BasicAuth struct {
Realm string
Secrets SecretProvider
}
/*
Checks the username/password combination from the request. Returns
either an empty string (authentication failed) or the name of the
authenticated user.
Supports MD5 and SHA1 password entries
*/
func (a *BasicAuth) CheckAuth(r *http.Request) string {
s := strings.SplitN(r.Header.Get("Authorization"), " ", 2)
if len(s) != 2 || s[0] != "Basic" {
return ""
}
b, err := base64.StdEncoding.DecodeString(s[1])
if err != nil {
return ""
}
pair := strings.SplitN(string(b), ":", 2)
if len(pair) != 2 {
return ""
}
passwd := a.Secrets(pair[0], a.Realm)
if passwd == "" {
return ""
}
if strings.HasPrefix(passwd, "{SHA}") {
d := sha1.New()
d.Write([]byte(pair[1]))
if subtle.ConstantTimeCompare([]byte(passwd[5:]), []byte(base64.StdEncoding.EncodeToString(d.Sum(nil)))) != 1 {
return ""
}
} else {
e := NewMD5Entry(passwd)
if e == nil {
return ""
}
if subtle.ConstantTimeCompare([]byte(passwd), MD5Crypt([]byte(pair[1]), e.Salt, e.Magic)) != 1 {
return ""
}
}
return pair[0]
}
/*
http.Handler for BasicAuth which initiates the authentication process
(or requires reauthentication).
*/
func (a *BasicAuth) RequireAuth(w http.ResponseWriter, r *http.Request) {
w.Header().Set("WWW-Authenticate", `Basic realm="`+a.Realm+`"`)
w.WriteHeader(401)
w.Write([]byte("401 Unauthorized\n"))
}
/*
BasicAuthenticator returns a function, which wraps an
AuthenticatedHandlerFunc converting it to http.HandlerFunc. This
wrapper function checks the authentication and either sends back
required authentication headers, or calls the wrapped function with
authenticated username in the AuthenticatedRequest.
*/
func (a *BasicAuth) Wrap(wrapped AuthenticatedHandlerFunc) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
if username := a.CheckAuth(r); username == "" {
a.RequireAuth(w, r)
} else {
ar := &AuthenticatedRequest{Request: *r, Username: username}
wrapped(w, ar)
}
}
}
func NewBasicAuthenticator(realm string, secrets SecretProvider) *BasicAuth {
return &BasicAuth{Realm: realm, Secrets: secrets}
}
|