diff options
| -rw-r--r-- | LICENSE | 27 | ||||
| -rw-r--r-- | doc.go | 126 | ||||
| -rw-r--r-- | sessions.go | 234 | ||||
| -rw-r--r-- | sessions_test.go | 197 | ||||
| -rw-r--r-- | store.go | 235 |
5 files changed, 819 insertions, 0 deletions
@@ -0,0 +1,27 @@ +Copyright (c) 2012 Rodrigo Moraes. All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: + + * Redistributions of source code must retain the above copyright +notice, this list of conditions and the following disclaimer. + * Redistributions in binary form must reproduce the above +copyright notice, this list of conditions and the following disclaimer +in the documentation and/or other materials provided with the +distribution. + * Neither the name of Google Inc. nor the names of its +contributors may be used to endorse or promote products derived from +this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. @@ -0,0 +1,126 @@ +// Copyright 2012 The Gorilla Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* +Package gorilla/sessions provides cookie and filesystem sessions and +infrastructure for custom session backends. + +The key features are: + + * Simple API: use it as an easy way to set signed (and optionally + encrypted) cookies. + * Built-in backends to store sessions in cookies or the filesystem. + * Flash messages: session values that last until read. + * Convenient way to switch session persistency (aka "remember me") and set + other attributes. + * Mechanism to rotate authentication and encryption keys. + * Multiple sessions per request, even using different backends. + * Interfaces and infrastructure for custom session backends: sessions from + different stores can be retrieved and batch-saved using a common API. + +Let's start with an example that shows the sessions API in a nutshell: + + import ( + "net/http" + "github.com/gorilla/sessions" + ) + + var store = sessions.NewCookieStore([]byte("something-very-secret")) + + func MyHandler(w http.ResponseWriter, r *http.Request) { + // Get a session. We're ignoring the error resulted from decoding an + // existing session: Get() always returns a session, even if empty. + session, _ := store.Get(r, "session-name") + // Set some session values. + session.Values["foo"] = "bar" + session.Values[42] = 43 + // Save it. + session.Save(r, w) + } + +First we initialize a session store calling NewCookieStore() and passing a +secret key used to authenticate the session. Inside the handler, we call +store.Get() to retrieve an existing session or a new one. Then we set some +session values in session.Values, which is a map[interface{}]interface{}. +And finally we call session.Save() to save the session in the response. + +That's all you need to know for the basic usage. Let's take a look at other +options, starting with flash messages. + +Flash messages are session values that last until read. The term appeared with +Ruby On Rails a few years back. When we request a flash message, it is removed +from the session. To add a flash, call session.AddFlash(), and to get all +flashes, call session.Flashes(). Here is an example: + + func MyHandler(w http.ResponseWriter, r *http.Request) { + // Get a session. + session, _ := store.Get(r, "session-name") + // Get the previously flashes, if any. + if flashes := session.Flashes(); len(flashes) > 0 { + // Just print the flash values. + fmt.Fprint(w, "%v", flashes) + } else { + // Set a new flash. + session.AddFlash("Hello, flash messages world!") + fmt.Fprint(w, "No flashes found.") + } + session.Save(r, w) + } + +Flash messages are useful to set information to be read after a redirection, +like after form submissions. + +By default, session cookies last for a month. This is probably too long for +some cases, but it is easy to change this and other attributes during +runtime. Sessions can be configured individually or the store can be +configured and then all sessions saved using it will use that configuration. +We access session.Options or store.Options to set a new configuration. The +fields are basically a subset of http.Cookie fields. Let's change the +maximum age of a session to one week: + + session.Options = &sessions.Options{ + Path: "/", + MaxAge: 86400 * 7, + } + +Sometimes we may want to change authentication and/or encryption keys without +breaking existing sessions. The CookieStore supports key rotation, and to use +it you just need to set multiple authentication and encryption keys, in pairs, +to be tested in order: + + var store = sessions.NewCookieStore( + []byte("new-authentication-key"), + []byte("new-encryption-key"), + []byte("old-authentication-key"), + []byte("old-encryption-key"), + ) + +New sessions will be saved using the first pair. Old sessions can still be +read because the first pair will fail, and the second will be tested. This +makes it easy to "rotate" secret keys and still be able to validate existing +sessions. Note: for all pairs the encryption key is optional; set it to nil +or omit it and and encryption won't be used. + +Multiple sessions can be used in the same request, even with different +session backends. When this happens, calling Save() on each session +individually would be cumbersome, so we have a way to save all sessions +at once: it's sessions.Save(). Here's an example: + + var store = sessions.NewCookieStore([]byte("something-very-secret")) + + func MyHandler(w http.ResponseWriter, r *http.Request) { + // Get a session and set a value. + session1, _ := store.Get(r, "session-one") + session1.Values["foo"] = "bar" + // Get another session and set another value. + session2, _ := store.Get(r, "session-two") + session2.Values[42] = 43 + // Save all sessions. + sessions.Save(r, w) + } + +This is possible because when we call Get() from a session store, it adds the +session to a common registry. Save() uses it to save all registered sessions. +*/ +package sessions diff --git a/sessions.go b/sessions.go new file mode 100644 index 0000000..53111b3 --- /dev/null +++ b/sessions.go @@ -0,0 +1,234 @@ +// Copyright 2012 The Gorilla Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package sessions + +import ( + "encoding/gob" + "fmt" + "net/http" + "time" + + "github.com/gorilla/context" +) + +// Default flashes key. +const flashesKey = "_flash" + +// Options -------------------------------------------------------------------- + +// Options stores configuration for a session or session store. +// +// Fields are a subset of http.Cookie fields. +type Options struct { + Path string + Domain string + // MaxAge=0 means no 'Max-Age' attribute specified. + // MaxAge<0 means delete cookie now, equivalently 'Max-Age: 0'. + // MaxAge>0 means Max-Age attribute present and given in seconds. + MaxAge int + Secure bool + HttpOnly bool +} + +// Session -------------------------------------------------------------------- + +// NewSession is called by session stores to create a new session instance. +func NewSession(store Store, name string) *Session { + return &Session{ + Values: make(map[interface{}]interface{}), + store: store, + name: name, + } +} + +// Session stores the values and optional configuration for a session. +type Session struct { + ID string + Values map[interface{}]interface{} + Options *Options + IsNew bool + store Store + name string +} + +// Flashes returns a slice of flash messages from the session. +// +// A single variadic argument is accepted, and it is optional: it defines +// the flash key. If not defined "_flash" is used by default. +func (s *Session) Flashes(vars ...string) []interface{} { + var flashes []interface{} + key := flashesKey + if len(vars) > 0 { + key = vars[0] + } + if v, ok := s.Values[key]; ok { + // Drop the flashes and return it. + delete(s.Values, key) + flashes = v.([]interface{}) + } + return flashes +} + +// AddFlash adds a flash message to the session. +// +// A single variadic argument is accepted, and it is optional: it defines +// the flash key. If not defined "_flash" is used by default. +func (s *Session) AddFlash(value interface{}, vars ...string) { + key := flashesKey + if len(vars) > 0 { + key = vars[0] + } + var flashes []interface{} + if v, ok := s.Values[key]; ok { + flashes = v.([]interface{}) + } + s.Values[key] = append(flashes, value) +} + +// Save is a convenience method to save this session. It is the same as calling +// store.Save(request, response, session) +func (s *Session) Save(r *http.Request, w http.ResponseWriter) error { + return s.store.Save(r, w, s) +} + +// Name returns the name used to register the session. +func (s *Session) Name() string { + return s.name +} + +// Store returns the session store used to register the session. +func (s *Session) Store() Store { + return s.store +} + +// Registry ------------------------------------------------------------------- + +// sessionInfo stores a session tracked by the registry. +type sessionInfo struct { + s *Session + e error +} + +// contextKey is the type used to store the registry in the context. +type contextKey int + +// registryKey is the key used to store the registry in the context. +const registryKey contextKey = 0 + +// GetRegistry returns a registry instance for the current request. +func GetRegistry(r *http.Request) *Registry { + registry := context.Get(r, registryKey) + if registry != nil { + return registry.(*Registry) + } + newRegistry := &Registry{ + request: r, + sessions: make(map[string]sessionInfo), + } + context.Set(r, registryKey, newRegistry) + return newRegistry +} + +// Registry stores sessions used during a request. +type Registry struct { + request *http.Request + sessions map[string]sessionInfo +} + +// Get registers and returns a session for the given name and session store. +// +// It returns a new session if there are no sessions registered for the name. +func (s *Registry) Get(store Store, name string) (session *Session, err error) { + if info, ok := s.sessions[name]; ok { + session, err = info.s, info.e + } else { + session, err = store.New(s.request, name) + session.name = name + s.sessions[name] = sessionInfo{s: session, e: err} + } + session.store = store + return +} + +// Save saves all sessions registered for the current request. +func (s *Registry) Save(w http.ResponseWriter) error { + var errMulti MultiError + for name, info := range s.sessions { + session := info.s + if session.store == nil { + errMulti = append(errMulti, fmt.Errorf( + "sessions: missing store for session %q", name)) + } else if err := session.store.Save(s.request, w, session); err != nil { + errMulti = append(errMulti, fmt.Errorf( + "sessions: error saving session %q -- %v", name, err)) + } + } + if errMulti != nil { + return errMulti + } + return nil +} + +// Helpers -------------------------------------------------------------------- + +func init() { + gob.Register([]interface{}{}) +} + +// Save saves all sessions used during the current request. +func Save(r *http.Request, w http.ResponseWriter) error { + return GetRegistry(r).Save(w) +} + +// NewCookie returns an http.Cookie with the options set. It also sets +// the Expires field calculated based on the MaxAge value, for Internet +// Explorer compatibility. +func NewCookie(name, value string, options *Options) *http.Cookie { + cookie := &http.Cookie{ + Name: name, + Value: value, + Path: options.Path, + Domain: options.Domain, + MaxAge: options.MaxAge, + Secure: options.Secure, + HttpOnly: options.HttpOnly, + } + if options.MaxAge > 0 { + d := time.Duration(options.MaxAge) * time.Second + cookie.Expires = time.Now().Add(d) + } else if options.MaxAge < 0 { + // Set it to the past to expire now. + cookie.Expires = time.Unix(1, 0) + } + return cookie +} + +// Error ---------------------------------------------------------------------- + +// MultiError stores multiple errors. +// +// Borrowed from the App Engine SDK. +type MultiError []error + +func (m MultiError) Error() string { + s, n := "", 0 + for _, e := range m { + if e != nil { + if n == 0 { + s = e.Error() + } + n++ + } + } + switch n { + case 0: + return "(0 errors)" + case 1: + return s + case 2: + return s + " (and 1 other error)" + } + return fmt.Sprintf("%s (and %d other errors)", s, n-1) +} diff --git a/sessions_test.go b/sessions_test.go new file mode 100644 index 0000000..3667d63 --- /dev/null +++ b/sessions_test.go @@ -0,0 +1,197 @@ +// Copyright 2012 The Gorilla Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package sessions + +import ( + "bytes" + "encoding/gob" + "net/http" + "testing" +) + +// ---------------------------------------------------------------------------- +// ResponseRecorder +// ---------------------------------------------------------------------------- +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// ResponseRecorder is an implementation of http.ResponseWriter that +// records its mutations for later inspection in tests. +type ResponseRecorder struct { + Code int // the HTTP response code from WriteHeader + HeaderMap http.Header // the HTTP response headers + Body *bytes.Buffer // if non-nil, the bytes.Buffer to append written data to + Flushed bool +} + +// NewRecorder returns an initialized ResponseRecorder. +func NewRecorder() *ResponseRecorder { + return &ResponseRecorder{ + HeaderMap: make(http.Header), + Body: new(bytes.Buffer), + } +} + +// DefaultRemoteAddr is the default remote address to return in RemoteAddr if +// an explicit DefaultRemoteAddr isn't set on ResponseRecorder. +const DefaultRemoteAddr = "1.2.3.4" + +// Header returns the response headers. +func (rw *ResponseRecorder) Header() http.Header { + return rw.HeaderMap +} + +// Write always succeeds and writes to rw.Body, if not nil. +func (rw *ResponseRecorder) Write(buf []byte) (int, error) { + if rw.Body != nil { + rw.Body.Write(buf) + } + if rw.Code == 0 { + rw.Code = http.StatusOK + } + return len(buf), nil +} + +// WriteHeader sets rw.Code. +func (rw *ResponseRecorder) WriteHeader(code int) { + rw.Code = code +} + +// Flush sets rw.Flushed to true. +func (rw *ResponseRecorder) Flush() { + rw.Flushed = true +} + +// ---------------------------------------------------------------------------- + +type FlashMessage struct { + Type int + Message string +} + +func TestFlashes(t *testing.T) { + var req *http.Request + var rsp *ResponseRecorder + var hdr http.Header + var err error + var ok bool + var cookies []string + var session *Session + var flashes []interface{} + + store := NewCookieStore([]byte("secret-key")) + + // Round 1 ---------------------------------------------------------------- + + req, _ = http.NewRequest("GET", "http://localhost:8080/", nil) + rsp = NewRecorder() + // Get a session. + if session, err = store.Get(req, "session-key"); err != nil { + t.Fatalf("Error getting session: %v", err) + } + // Get a flash. + flashes = session.Flashes() + if len(flashes) != 0 { + t.Errorf("Expected empty flashes; Got %v", flashes) + } + // Add some flashes. + session.AddFlash("foo") + session.AddFlash("bar") + // Custom key. + session.AddFlash("baz", "custom_key") + // Save. + if err = Save(req, rsp); err != nil { + t.Fatalf("Error saving session: %v", err) + } + hdr = rsp.Header() + cookies, ok = hdr["Set-Cookie"] + if !ok || len(cookies) != 1 { + t.Fatalf("No cookies. Header:", hdr) + } + + // Round 2 ---------------------------------------------------------------- + + req, _ = http.NewRequest("GET", "http://localhost:8080/", nil) + req.Header.Add("Cookie", cookies[0]) + rsp = NewRecorder() + // Get a session. + if session, err = store.Get(req, "session-key"); err != nil { + t.Fatalf("Error getting session: %v", err) + } + // Check all saved values. + flashes = session.Flashes() + if len(flashes) != 2 { + t.Fatalf("Expected flashes; Got %v", flashes) + } + if flashes[0] != "foo" || flashes[1] != "bar" { + t.Errorf("Expected foo,bar; Got %v", flashes) + } + flashes = session.Flashes() + if len(flashes) != 0 { + t.Errorf("Expected dumped flashes; Got %v", flashes) + } + // Custom key. + flashes = session.Flashes("custom_key") + if len(flashes) != 1 { + t.Errorf("Expected flashes; Got %v", flashes) + } else if flashes[0] != "baz" { + t.Errorf("Expected baz; Got %v", flashes) + } + flashes = session.Flashes("custom_key") + if len(flashes) != 0 { + t.Errorf("Expected dumped flashes; Got %v", flashes) + } + + // Round 3 ---------------------------------------------------------------- + // Custom type + + req, _ = http.NewRequest("GET", "http://localhost:8080/", nil) + rsp = NewRecorder() + // Get a session. + if session, err = store.Get(req, "session-key"); err != nil { + t.Fatalf("Error getting session: %v", err) + } + // Get a flash. + flashes = session.Flashes() + if len(flashes) != 0 { + t.Errorf("Expected empty flashes; Got %v", flashes) + } + // Add some flashes. + session.AddFlash(&FlashMessage{42, "foo"}) + // Save. + if err = Save(req, rsp); err != nil { + t.Fatalf("Error saving session: %v", err) + } + hdr = rsp.Header() + cookies, ok = hdr["Set-Cookie"] + if !ok || len(cookies) != 1 { + t.Fatalf("No cookies. Header:", hdr) + } + + // Round 4 ---------------------------------------------------------------- + // Custom type + + req, _ = http.NewRequest("GET", "http://localhost:8080/", nil) + req.Header.Add("Cookie", cookies[0]) + rsp = NewRecorder() + // Get a session. + if session, err = store.Get(req, "session-key"); err != nil { + t.Fatalf("Error getting session: %v", err) + } + // Check all saved values. + flashes = session.Flashes() + if len(flashes) != 1 { + t.Fatalf("Expected flashes; Got %v", flashes) + } + custom := flashes[0].(FlashMessage) + if custom.Type != 42 || custom.Message != "foo" { + t.Errorf("Expected %#v, got %#v", FlashMessage{42, "foo"}, custom) + } +} + +func init() { + gob.Register(FlashMessage{}) +} diff --git a/store.go b/store.go new file mode 100644 index 0000000..7f0a2cb --- /dev/null +++ b/store.go @@ -0,0 +1,235 @@ +// Copyright 2012 The Gorilla Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package sessions + +import ( + "encoding/base32" + "io" + "net/http" + "os" + "strings" + "sync" + + "github.com/gorilla/securecookie" +) + +// Store is an interface for custom session stores. +type Store interface { + Get(r *http.Request, name string) (*Session, error) + New(r *http.Request, name string) (*Session, error) + Save(r *http.Request, w http.ResponseWriter, s *Session) error +} + +// CookieStore ---------------------------------------------------------------- + +// NewCookieStore returns a new CookieStore. +// +// Keys are defined in pairs to allow key rotation, but the common case is +// to set a single authentication key and optionally an encryption key. +// +// The first key in a pair is used for authentication and the second for +// encryption. The encryption key can be set to nil or omitted in the last +// pair, but the authentication key is required in all pairs. +// +// It is recommended to use an authentication key with 32 or 64 bytes. +// The encryption key, if set, must be either 16, 24, or 32 bytes to select +// AES-128, AES-192, or AES-256 modes. +// +// Use the convenience function securecookie.GenerateRandomKey() to create +// strong keys. +func NewCookieStore(keyPairs ...[]byte) *CookieStore { + return &CookieStore{ + Codecs: securecookie.CodecsFromPairs(keyPairs...), + Options: &Options{ + Path: "/", + MaxAge: 86400 * 30, + }, + } +} + +// CookieStore stores sessions using secure cookies. +type CookieStore struct { + Codecs []securecookie.Codec + Options *Options // default configuration +} + +// Get returns a session for the given name after adding it to the registry. +// +// It returns a new session if the sessions doesn't exist. Access IsNew on +// the session to check if it is an existing session or a new one. +// +// It returns a new session and an error if the session exists but could +// not be decoded. +func (s *CookieStore) Get(r *http.Request, name string) (*Session, error) { + return GetRegistry(r).Get(s, name) +} + +// New returns a session for the given name without adding it to the registry. +// +// The difference between New() and Get() is that calling New() twice will +// decode the session data twice, while Get() registers and reuses the same +// decoded session after the first call. +func (s *CookieStore) New(r *http.Request, name string) (*Session, error) { + session := NewSession(s, name) + session.Options = &(*s.Options) + session.IsNew = true + var err error + if c, errCookie := r.Cookie(name); errCookie == nil { + err = securecookie.DecodeMulti(name, c.Value, &session.Values, + s.Codecs...) + if err == nil { + session.IsNew = false + } + } + return session, err +} + +// Save adds a single session to the response. +func (s *CookieStore) Save(r *http.Request, w http.ResponseWriter, + session *Session) error { + encoded, err := securecookie.EncodeMulti(session.Name(), session.Values, + s.Codecs...) + if err != nil { + return err + } + http.SetCookie(w, NewCookie(session.Name(), encoded, session.Options)) + return nil +} + +// FilesystemStore ------------------------------------------------------------ + +var fileMutex sync.RWMutex + +// NewFilesystemStore returns a new FilesystemStore. +// +// The path argument is the directory where sessions will be saved. If empty +// it will use os.TempDir(). +// +// See NewCookieStore() for a description of the other parameters. +func NewFilesystemStore(path string, keyPairs ...[]byte) *FilesystemStore { + if path == "" { + path = os.TempDir() + } + if path[len(path)-1] != '/' { + path += "/" + } + return &FilesystemStore{ + Codecs: securecookie.CodecsFromPairs(keyPairs...), + Options: &Options{ + Path: "/", + MaxAge: 86400 * 30, + }, + path: path, + } +} + +// FilesystemStore stores sessions in the filesystem. +// +// It also serves as a referece for custom stores. +// +// This store is still experimental and not well tested. Feedback is welcome. +type FilesystemStore struct { + Codecs []securecookie.Codec + Options *Options // default configuration + path string +} + +// Get returns a session for the given name after adding it to the registry. +// +// See CookieStore.Get(). +func (s *FilesystemStore) Get(r *http.Request, name string) (*Session, error) { + return GetRegistry(r).Get(s, name) +} + +// New returns a session for the given name without adding it to the registry. +// +// See CookieStore.New(). +func (s *FilesystemStore) New(r *http.Request, name string) (*Session, error) { + session := NewSession(s, name) + session.Options = &(*s.Options) + session.IsNew = true + var err error + if c, errCookie := r.Cookie(name); errCookie == nil { + err = securecookie.DecodeMulti(name, c.Value, &session.ID, s.Codecs...) + if err == nil { + err = s.load(session) + if err == nil { + session.IsNew = false + } + } + } + return session, err +} + +// Save adds a single session to the response. +func (s *FilesystemStore) Save(r *http.Request, w http.ResponseWriter, + session *Session) error { + if session.ID == "" { + // Because the ID is used in the filename, encode it to + // use alphanumeric characters only. + session.ID = strings.TrimRight( + base32.StdEncoding.EncodeToString( + securecookie.GenerateRandomKey(32)), "=") + } + if err := s.save(session); err != nil { + return err + } + encoded, err := securecookie.EncodeMulti(session.Name(), session.ID, + s.Codecs...) + if err != nil { + return err + } + http.SetCookie(w, NewCookie(session.Name(), encoded, session.Options)) + return nil +} + +// save writes encoded session.Values to a file. +func (s *FilesystemStore) save(session *Session) error { + encoded, err := securecookie.EncodeMulti(session.Name(), session.Values, + s.Codecs...) + if err != nil { + return err + } + filename := s.path + "session_" + session.ID + fileMutex.Lock() + defer fileMutex.Unlock() + fp, err2 := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE, 0600) + if err2 != nil { + return err2 + } + if _, err = fp.Write([]byte(encoded)); err != nil { + return err + } + fp.Close() + return nil +} + +// load reads a file and decodes its content into session.Values. +func (s *FilesystemStore) load(session *Session) error { + filename := s.path + "session_" + session.ID + fp, err := os.OpenFile(filename, os.O_RDONLY, 0400) + if err != nil { + return err + } + defer fp.Close() + var fdata []byte + buf := make([]byte, 128) + for { + var n int + n, err = fp.Read(buf[0:]) + fdata = append(fdata, buf[0:n]...) + if err != nil { + if err == io.EOF { + break + } + return err + } + } + if err = securecookie.DecodeMulti(session.Name(), string(fdata), + &session.Values, s.Codecs...); err != nil { + return err + } + return nil +} |