|
| 1 | +package providers |
| 2 | + |
| 3 | +import ( |
| 4 | + "bytes" |
| 5 | + "encoding/base64" |
| 6 | + "encoding/json" |
| 7 | + "errors" |
| 8 | + "fmt" |
| 9 | + "io/ioutil" |
| 10 | + "log" |
| 11 | + "net/http" |
| 12 | + "net/url" |
| 13 | + "strings" |
| 14 | + "time" |
| 15 | + |
| 16 | + "github.com/bitly/oauth2_proxy/api" |
| 17 | +) |
| 18 | + |
| 19 | +type OktaProvider struct { |
| 20 | + *ProviderData |
| 21 | +} |
| 22 | + |
| 23 | +func NewOktaProvider(p *ProviderData) *OktaProvider { |
| 24 | + p.ProviderName = "Okta" |
| 25 | + if p.Scope == "" { |
| 26 | + p.Scope = "openid profile email offline_access" |
| 27 | + } |
| 28 | + return &OktaProvider{ProviderData: p} |
| 29 | +} |
| 30 | + |
| 31 | +func (p *OktaProvider) SetOktaDomain(domain string) { |
| 32 | + if p.LoginURL == nil || p.LoginURL.String() == "" { |
| 33 | + p.LoginURL = &url.URL{ |
| 34 | + Scheme: "https", |
| 35 | + Host: domain, |
| 36 | + Path: "/oauth2/v1/authorize", |
| 37 | + } |
| 38 | + } |
| 39 | + if p.RedeemURL == nil || p.RedeemURL.String() == "" { |
| 40 | + p.RedeemURL = &url.URL{ |
| 41 | + Scheme: "https", |
| 42 | + Host: domain, |
| 43 | + Path: "/oauth2/v1/token", |
| 44 | + } |
| 45 | + } |
| 46 | + if p.ValidateURL == nil || p.ValidateURL.String() == "" { |
| 47 | + p.ValidateURL = &url.URL{ |
| 48 | + Scheme: "https", |
| 49 | + Host: domain, |
| 50 | + Path: "/oauth2/v1/userinfo", |
| 51 | + } |
| 52 | + } |
| 53 | + |
| 54 | +} |
| 55 | + |
| 56 | +func getOktaHeader(access_token string) http.Header { |
| 57 | + header := make(http.Header) |
| 58 | + header.Set("Authorization", fmt.Sprintf("Bearer %s", access_token)) |
| 59 | + return header |
| 60 | +} |
| 61 | + |
| 62 | +func emailFromOktaIdToken(idToken string) (string, error) { |
| 63 | + |
| 64 | + // id_token is a base64 encode ID token payload |
| 65 | + // https://developers.google.com/accounts/docs/OAuth2Login#obtainuserinfo |
| 66 | + jwt := strings.Split(idToken, ".") |
| 67 | + b, err := base64.RawURLEncoding.DecodeString(jwt[1]) |
| 68 | + if err != nil { |
| 69 | + return "", err |
| 70 | + } |
| 71 | + |
| 72 | + var email struct { |
| 73 | + Email string `json:"email"` |
| 74 | + } |
| 75 | + err = json.Unmarshal(b, &email) |
| 76 | + if err != nil { |
| 77 | + return "", err |
| 78 | + } |
| 79 | + if email.Email == "" { |
| 80 | + return "", errors.New("Okta ID token missing email") |
| 81 | + } |
| 82 | + |
| 83 | + return email.Email, nil |
| 84 | +} |
| 85 | + |
| 86 | +func (p *OktaProvider) GetUserName(s *SessionState) (string, error) { |
| 87 | + req, err := http.NewRequest("GET", |
| 88 | + p.ValidateURL.String(), nil) |
| 89 | + if err != nil { |
| 90 | + log.Printf("failed building request %s", err) |
| 91 | + return "", err |
| 92 | + } |
| 93 | + req.Header = getOktaHeader(s.AccessToken) |
| 94 | + json, err := api.Request(req) |
| 95 | + if err != nil { |
| 96 | + log.Printf("failed making request %s", err) |
| 97 | + return "", err |
| 98 | + } |
| 99 | + return json.Get("preferred_username").String() |
| 100 | +} |
| 101 | + |
| 102 | +func (p *OktaProvider) ValidateSessionState(s *SessionState) bool { |
| 103 | + return validateToken(p, s.AccessToken, getOktaHeader(s.AccessToken)) |
| 104 | +} |
| 105 | + |
| 106 | +func (p *OktaProvider) Redeem(redirectURL, code string) (s *SessionState, err error) { |
| 107 | + if code == "" { |
| 108 | + err = errors.New("missing code") |
| 109 | + return |
| 110 | + } |
| 111 | + |
| 112 | + params := url.Values{} |
| 113 | + params.Add("redirect_uri", redirectURL) |
| 114 | + params.Add("client_id", p.ClientID) |
| 115 | + params.Add("client_secret", p.ClientSecret) |
| 116 | + params.Add("code", code) |
| 117 | + params.Add("grant_type", "authorization_code") |
| 118 | + var req *http.Request |
| 119 | + req, err = http.NewRequest("POST", p.RedeemURL.String(), bytes.NewBufferString(params.Encode())) |
| 120 | + if err != nil { |
| 121 | + return |
| 122 | + } |
| 123 | + req.Header.Set("Content-Type", "application/x-www-form-urlencoded") |
| 124 | + |
| 125 | + resp, err := http.DefaultClient.Do(req) |
| 126 | + if err != nil { |
| 127 | + return |
| 128 | + } |
| 129 | + var body []byte |
| 130 | + body, err = ioutil.ReadAll(resp.Body) |
| 131 | + resp.Body.Close() |
| 132 | + if err != nil { |
| 133 | + return |
| 134 | + } |
| 135 | + |
| 136 | + if resp.StatusCode != 200 { |
| 137 | + err = fmt.Errorf("got %d from %q %s", resp.StatusCode, p.RedeemURL.String(), body) |
| 138 | + return |
| 139 | + } |
| 140 | + |
| 141 | + var jsonResponse struct { |
| 142 | + AccessToken string `json:"access_token"` |
| 143 | + RefreshToken string `json:"refresh_token"` |
| 144 | + ExpiresIn int64 `json:"expires_in"` |
| 145 | + IdToken string `json:"id_token"` |
| 146 | + } |
| 147 | + err = json.Unmarshal(body, &jsonResponse) |
| 148 | + if err != nil { |
| 149 | + return |
| 150 | + } |
| 151 | + var email string |
| 152 | + email, err = emailFromOktaIdToken(jsonResponse.IdToken) |
| 153 | + |
| 154 | + if err != nil { |
| 155 | + return |
| 156 | + } |
| 157 | + s = &SessionState{ |
| 158 | + AccessToken: jsonResponse.AccessToken, |
| 159 | + ExpiresOn: time.Now().Add(time.Duration(jsonResponse.ExpiresIn) * time.Second).Truncate(time.Second), |
| 160 | + RefreshToken: jsonResponse.RefreshToken, |
| 161 | + Email: email, |
| 162 | + } |
| 163 | + return |
| 164 | +} |
| 165 | + |
| 166 | +func (p *OktaProvider) RefreshSessionIfNeeded(s *SessionState) (bool, error) { |
| 167 | + //@todo: Remove from here before accepting PR. This is for local testing |
| 168 | + if s == nil || s.ExpiresOn.After(time.Now()) || s.RefreshToken == "" { |
| 169 | + return false, nil |
| 170 | + } |
| 171 | + |
| 172 | + newToken, duration, err := p.redeemRefreshToken(s.RefreshToken) |
| 173 | + if err != nil { |
| 174 | + return false, err |
| 175 | + } |
| 176 | + |
| 177 | + // re-check that the user is in the proper google group(s) |
| 178 | + if !p.ValidateGroup(s.Email) { |
| 179 | + return false, fmt.Errorf("%s is no longer in the group(s)", s.Email) |
| 180 | + } |
| 181 | + |
| 182 | + origExpiration := s.ExpiresOn |
| 183 | + s.AccessToken = newToken |
| 184 | + s.ExpiresOn = time.Now().Add(duration).Truncate(time.Second) |
| 185 | + log.Printf("refreshed access token %s (expired on %s)", s, origExpiration) |
| 186 | + return true, nil |
| 187 | +} |
| 188 | + |
| 189 | +func (p *OktaProvider) redeemRefreshToken(refreshToken string) (token string, expires time.Duration, err error) { |
| 190 | + params := url.Values{} |
| 191 | + params.Add("client_id", p.ClientID) |
| 192 | + params.Add("client_secret", p.ClientSecret) |
| 193 | + params.Add("refresh_token", refreshToken) |
| 194 | + params.Add("grant_type", "refresh_token") |
| 195 | + var req *http.Request |
| 196 | + req, err = http.NewRequest("POST", p.RedeemURL.String(), bytes.NewBufferString(params.Encode())) |
| 197 | + if err != nil { |
| 198 | + return |
| 199 | + } |
| 200 | + req.Header.Set("Content-Type", "application/x-www-form-urlencoded") |
| 201 | + |
| 202 | + resp, err := http.DefaultClient.Do(req) |
| 203 | + if err != nil { |
| 204 | + return |
| 205 | + } |
| 206 | + var body []byte |
| 207 | + body, err = ioutil.ReadAll(resp.Body) |
| 208 | + resp.Body.Close() |
| 209 | + if err != nil { |
| 210 | + return |
| 211 | + } |
| 212 | + |
| 213 | + if resp.StatusCode != 200 { |
| 214 | + err = fmt.Errorf("got %d from %q %s", resp.StatusCode, p.RedeemURL.String(), body) |
| 215 | + return |
| 216 | + } |
| 217 | + |
| 218 | + var data struct { |
| 219 | + AccessToken string `json:"access_token"` |
| 220 | + ExpiresIn int64 `json:"expires_in"` |
| 221 | + } |
| 222 | + err = json.Unmarshal(body, &data) |
| 223 | + if err != nil { |
| 224 | + return |
| 225 | + } |
| 226 | + token = data.AccessToken |
| 227 | + expires = time.Duration(data.ExpiresIn) * time.Second |
| 228 | + return |
| 229 | +} |
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