auth
2014-08-16
Parent:3423c552e249
auth/util.go
Implement CSRF prevention and pass info to confirmation. Implement CSRF prevention using the nosurf package. Note that the handler still needs to be wrapped before this will work. Pass info on the authorization being requested (namely the client and the scope) to the RenderConfirmation page so that the user can make an educated decision.
| paddy@6 | 1 package auth |
| paddy@0 | 2 |
| paddy@0 | 3 import ( |
| paddy@0 | 4 "encoding/base64" |
| paddy@0 | 5 "errors" |
| paddy@1 | 6 "fmt" |
| paddy@0 | 7 "net/http" |
| paddy@1 | 8 "net/url" |
| paddy@0 | 9 "strings" |
| paddy@1 | 10 |
| paddy@1 | 11 "code.google.com/p/go-uuid/uuid" |
| paddy@0 | 12 ) |
| paddy@0 | 13 |
| paddy@0 | 14 var ( |
| paddy@0 | 15 BasicAuthNotSetError = errors.New("Authorization header not set.") |
| paddy@0 | 16 InvalidBasicAuthTypeError = errors.New("Invalid basic auth type.") |
| paddy@0 | 17 InvalidBasicAuthMessage = errors.New("Invalid basic auth format.") |
| paddy@0 | 18 ) |
| paddy@0 | 19 |
| paddy@0 | 20 // Parse basic authentication header |
| paddy@0 | 21 type BasicAuth struct { |
| paddy@0 | 22 Username string |
| paddy@0 | 23 Password string |
| paddy@0 | 24 } |
| paddy@0 | 25 |
| paddy@0 | 26 // Return authorization header data |
| paddy@0 | 27 func CheckBasicAuth(r *http.Request) (BasicAuth, error) { |
| paddy@0 | 28 if r.Header.Get("Authorization") == "" { |
| paddy@0 | 29 return BasicAuth{}, BasicAuthNotSetError |
| paddy@0 | 30 } |
| paddy@0 | 31 |
| paddy@0 | 32 s := strings.SplitN(r.Header.Get("Authorization"), " ", 2) |
| paddy@0 | 33 if len(s) != 2 || s[0] != "Basic" { |
| paddy@0 | 34 return BasicAuth{}, InvalidBasicAuthTypeError |
| paddy@0 | 35 } |
| paddy@0 | 36 |
| paddy@0 | 37 b, err := base64.StdEncoding.DecodeString(s[1]) |
| paddy@0 | 38 if err != nil { |
| paddy@0 | 39 return BasicAuth{}, err |
| paddy@0 | 40 } |
| paddy@0 | 41 pair := strings.SplitN(string(b), ":", 2) |
| paddy@0 | 42 if len(pair) != 2 { |
| paddy@0 | 43 return BasicAuth{}, InvalidBasicAuthMessage |
| paddy@0 | 44 } |
| paddy@0 | 45 |
| paddy@0 | 46 return BasicAuth{Username: pair[0], Password: pair[1]}, nil |
| paddy@0 | 47 } |
| paddy@0 | 48 |
| paddy@0 | 49 // getClientAuth checks client basic authentication in params if allowed, |
| paddy@0 | 50 // otherwise gets it from the header. |
| paddy@0 | 51 func getClientAuth(r *http.Request, allowQueryParams bool) (BasicAuth, error) { |
| paddy@0 | 52 |
| paddy@0 | 53 if allowQueryParams { |
| paddy@0 | 54 // Allow for auth without password |
| paddy@0 | 55 if _, hasSecret := r.Form["client_secret"]; hasSecret { |
| paddy@0 | 56 auth := BasicAuth{ |
| paddy@0 | 57 Username: r.Form.Get("client_id"), |
| paddy@0 | 58 Password: r.Form.Get("client_secret"), |
| paddy@0 | 59 } |
| paddy@0 | 60 if auth.Username != "" { |
| paddy@0 | 61 return auth, nil |
| paddy@0 | 62 } |
| paddy@0 | 63 } |
| paddy@0 | 64 } |
| paddy@0 | 65 |
| paddy@0 | 66 return CheckBasicAuth(r) |
| paddy@0 | 67 } |
| paddy@1 | 68 |
| paddy@1 | 69 func newToken() string { |
| paddy@1 | 70 return base64.StdEncoding.EncodeToString([]byte(uuid.New())) |
| paddy@1 | 71 } |
| paddy@1 | 72 |
| paddy@1 | 73 // validateURI validates that redirectURI is contained in baseURI |
| paddy@1 | 74 func validateURI(baseURI string, redirectURI string) error { |
| paddy@1 | 75 if baseURI == "" || redirectURI == "" { |
| paddy@1 | 76 return errors.New("urls cannot be blank.") |
| paddy@1 | 77 } |
| paddy@1 | 78 |
| paddy@1 | 79 // parse base url |
| paddy@1 | 80 base, err := url.Parse(baseURI) |
| paddy@1 | 81 if err != nil { |
| paddy@1 | 82 return err |
| paddy@1 | 83 } |
| paddy@1 | 84 |
| paddy@1 | 85 // parse passed url |
| paddy@1 | 86 redirect, err := url.Parse(redirectURI) |
| paddy@1 | 87 if err != nil { |
| paddy@1 | 88 return err |
| paddy@1 | 89 } |
| paddy@1 | 90 |
| paddy@1 | 91 // must not have fragment |
| paddy@1 | 92 if base.Fragment != "" || redirect.Fragment != "" { |
| paddy@1 | 93 return errors.New("url must not include fragment.") |
| paddy@1 | 94 } |
| paddy@1 | 95 |
| paddy@1 | 96 // check if urls match |
| paddy@1 | 97 if base.Scheme == redirect.Scheme && base.Host == redirect.Host && len(redirect.Path) >= len(base.Path) && strings.HasPrefix(redirect.Path, base.Path) { |
| paddy@1 | 98 return nil |
| paddy@1 | 99 } |
| paddy@1 | 100 |
| paddy@1 | 101 return errors.New(fmt.Sprintf("urls don't validate: %s / %s\n", baseURI, redirectURI)) |
| paddy@1 | 102 } |