auth
auth/token.go
Switch to a JWT approach. We're going to use a JWT as our access tokens (as discussed in &yet's excellent post https://blog.andyet.com/2015/05/12/micro-services-user-info-and-auth and my ensuing conversation with Fritzy). The benefit of this approach is that we can do authentication and even some authorization without touching the database at all. The drawback is that we can no longer revoke access tokens, only the refresh tokens that grant the access tokens. We need a new config variable to set our private key, used to sign the JWT. We get to remove our token handlers, as we no longer can revoke tokens, so there's no purpose in getting information about it or listing them. Our tokenStore revokeToken gets to be simplified, as it will only ever be used for refresh tokens now. We also updated our postgres and memstore implementations. We added a helper method for generating the signed "access token" (our JWT) and started using it in the places where we're creating a Token. We get to remove the `revoked` SQL column for the tokens table, and rename the `refresh_revoked` column to just be `revoked`. We shortened our access token expiration to 15 minutes instead of an hour, to deal with the token not being revokable.
1 package auth
3 import (
4 "encoding/json"
5 "errors"
6 "log"
7 "net/http"
8 "strings"
9 "time"
11 "code.secondbit.org/uuid.hg"
13 "github.com/dgrijalva/jwt-go"
14 )
16 const (
17 defaultTokenExpiration = 900 // fifteen minutes
18 )
20 func init() {
21 RegisterGrantType("refresh_token", GrantType{
22 Validate: refreshTokenValidate,
23 Invalidate: refreshTokenInvalidate,
24 IssuesRefresh: true,
25 ReturnToken: RenderJSONToken,
26 AuditString: refreshTokenAuditString,
27 })
28 }
30 var (
31 // ErrNoTokenStore is returned when a Context tries to act on a tokenStore without setting one first.
32 ErrNoTokenStore = errors.New("no tokenStore was specified for the Context")
33 // ErrTokenNotFound is returned when a Token is requested but not found in a tokenStore.
34 ErrTokenNotFound = errors.New("token not found in tokenStore")
35 // ErrTokenAlreadyExists is returned when a Token is added to a tokenStore, but another Token with
36 // the same AccessToken property already exists in the tokenStore.
37 ErrTokenAlreadyExists = errors.New("token already exists in tokenStore")
38 )
40 // Token represents an access and/or refresh token that the Client can use to access user data
41 // or obtain a new access token.
42 type Token struct {
43 AccessToken string
44 RefreshToken string
45 Created time.Time
46 CreatedFrom string
47 ExpiresIn int32
48 TokenType string
49 Scopes Scopes
50 ProfileID uuid.ID
51 ClientID uuid.ID
52 Revoked bool
53 }
55 func (t Token) GenerateAccessToken(privateKey []byte) (string, error) {
56 access := jwt.New(jwt.SigningMethodHS256)
57 access.Claims["iss"] = t.ClientID
58 access.Claims["sub"] = t.ProfileID
59 access.Claims["exp"] = t.Created.Add(defaultTokenExpiration * time.Second).Unix()
60 access.Claims["nbf"] = t.Created.Add(-2 * time.Minute).Unix()
61 access.Claims["iat"] = t.Created.Unix()
62 access.Claims["scope"] = strings.Join(t.Scopes.Strings(), " ")
63 return access.SignedString(privateKey)
64 }
66 // BUG(paddy): Now that access tokens are generated and have a meaning, refresh tokens should be the primary key
68 type tokenStore interface {
69 getToken(token string, refresh bool) (Token, error)
70 saveToken(token Token) error
71 revokeToken(token string) error
72 getTokensByProfileID(profileID uuid.ID, num, offset int) ([]Token, error)
73 revokeTokensByProfileID(profileID uuid.ID) error
74 revokeTokensByClientID(clientID uuid.ID) error
75 }
77 func (m *memstore) getToken(token string, refresh bool) (Token, error) {
78 if refresh {
79 t, err := m.lookupTokenByRefresh(token)
80 if err != nil {
81 return Token{}, err
82 }
83 token = t
84 }
85 m.tokenLock.RLock()
86 defer m.tokenLock.RUnlock()
87 result, ok := m.tokens[token]
88 if !ok {
89 return Token{}, ErrTokenNotFound
90 }
91 return result, nil
92 }
94 func (m *memstore) saveToken(token Token) error {
95 m.tokenLock.Lock()
96 defer m.tokenLock.Unlock()
97 _, ok := m.tokens[token.AccessToken]
98 if ok {
99 return ErrTokenAlreadyExists
100 }
101 m.tokens[token.AccessToken] = token
102 if token.RefreshToken != "" {
103 m.refreshTokenLookup[token.RefreshToken] = token.AccessToken
104 }
105 if _, ok = m.profileTokenLookup[token.ProfileID.String()]; ok {
106 m.profileTokenLookup[token.ProfileID.String()] = append(m.profileTokenLookup[token.ProfileID.String()], token.AccessToken)
107 } else {
108 m.profileTokenLookup[token.ProfileID.String()] = []string{token.AccessToken}
109 }
110 return nil
111 }
113 func (m *memstore) revokeToken(token string) error {
114 token, err := m.lookupTokenByRefresh(token)
115 if err != nil {
116 return err
117 }
118 m.tokenLock.Lock()
119 defer m.tokenLock.Unlock()
120 t, ok := m.tokens[token]
121 if !ok {
122 return ErrTokenNotFound
123 }
124 t.Revoked = true
125 m.tokens[token] = t
126 return nil
127 }
129 func (m *memstore) revokeTokensByProfileID(profileID uuid.ID) error {
130 ids, err := m.lookupTokensByProfileID(profileID.String())
131 if err != nil {
132 return err
133 }
134 if len(ids) < 1 {
135 return ErrProfileNotFound
136 }
137 m.tokenLock.Lock()
138 defer m.tokenLock.Unlock()
139 for _, id := range ids {
140 token := m.tokens[id]
141 token.Revoked = true
142 m.tokens[id] = token
143 }
144 return nil
145 }
147 func (m *memstore) revokeTokensByClientID(clientID uuid.ID) error {
148 m.tokenLock.Lock()
149 defer m.tokenLock.Unlock()
150 for id, token := range m.tokens {
151 if !token.ClientID.Equal(clientID) {
152 continue
153 }
154 token.Revoked = true
155 m.tokens[id] = token
156 }
157 return nil
158 }
160 func (m *memstore) getTokensByProfileID(profileID uuid.ID, num, offset int) ([]Token, error) {
161 ids, err := m.lookupTokensByProfileID(profileID.String())
162 if err != nil {
163 return []Token{}, err
164 }
165 if len(ids) > num+offset {
166 ids = ids[offset : num+offset]
167 } else if len(ids) > offset {
168 ids = ids[offset:]
169 } else {
170 return []Token{}, nil
171 }
172 tokens := []Token{}
173 for _, id := range ids {
174 token, err := m.getToken(id, false)
175 if err != nil {
176 return []Token{}, err
177 }
178 tokens = append(tokens, token)
179 }
180 return tokens, nil
181 }
183 func refreshTokenValidate(w http.ResponseWriter, r *http.Request, context Context) (scopes Scopes, profileID uuid.ID, valid bool) {
184 enc := json.NewEncoder(w)
185 refresh := r.PostFormValue("refresh_token")
186 if refresh == "" {
187 w.WriteHeader(http.StatusBadRequest)
188 renderJSONError(enc, "invalid_request")
189 return
190 }
191 token, err := context.GetToken(refresh, true)
192 if err != nil {
193 if err == ErrTokenNotFound {
194 w.WriteHeader(http.StatusBadRequest)
195 renderJSONError(enc, "invalid_grant")
196 return
197 }
198 log.Println("Error exchanging refresh token:", err)
199 w.WriteHeader(http.StatusInternalServerError)
200 renderJSONError(enc, "server_error")
201 return
202 }
203 clientID, _, ok := getClientAuth(w, r, true)
204 if !ok {
205 return
206 }
207 if !token.ClientID.Equal(clientID) {
208 w.WriteHeader(http.StatusBadRequest)
209 renderJSONError(enc, "invalid_grant")
210 return
211 }
212 if token.Revoked {
213 w.WriteHeader(http.StatusBadRequest)
214 renderJSONError(enc, "invalid_grant")
215 return
216 }
217 return token.Scopes, token.ProfileID, true
218 }
220 func refreshTokenInvalidate(r *http.Request, context Context) error {
221 refresh := r.PostFormValue("refresh_token")
222 if refresh == "" {
223 return ErrTokenNotFound
224 }
225 return context.RevokeToken(refresh)
226 }
228 func refreshTokenAuditString(r *http.Request) string {
229 return "refresh_token:" + r.PostFormValue("refresh_token")
230 }