gotosocial/vendor/github.com/quasoft/memstore/memstore.go

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package memstore
import (
"bytes"
"encoding/base32"
"encoding/gob"
"fmt"
"net/http"
"strings"
"github.com/gorilla/securecookie"
"github.com/gorilla/sessions"
)
// MemStore is an in-memory implementation of gorilla/sessions, suitable
// for use in tests and development environments. Do not use in production.
// Values are cached in a map. The cache is protected and can be used by
// multiple goroutines.
type MemStore struct {
Codecs []securecookie.Codec
Options *sessions.Options
cache *cache
}
type valueType map[interface{}]interface{}
// NewMemStore returns a new MemStore.
//
// 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 NewMemStore(keyPairs ...[]byte) *MemStore {
store := MemStore{
Codecs: securecookie.CodecsFromPairs(keyPairs...),
Options: &sessions.Options{
Path: "/",
MaxAge: 86400 * 30,
},
cache: newCache(),
}
store.MaxAge(store.Options.MaxAge)
return &store
}
// 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 (m *MemStore) Get(r *http.Request, name string) (*sessions.Session, error) {
return sessions.GetRegistry(r).Get(m, 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 (m *MemStore) New(r *http.Request, name string) (*sessions.Session, error) {
session := sessions.NewSession(m, name)
options := *m.Options
session.Options = &options
session.IsNew = true
c, err := r.Cookie(name)
if err != nil {
// Cookie not found, this is a new session
return session, nil
}
err = securecookie.DecodeMulti(name, c.Value, &session.ID, m.Codecs...)
if err != nil {
// Value could not be decrypted, consider this is a new session
return session, err
}
v, ok := m.cache.value(session.ID)
if !ok {
// No value found in cache, don't set any values in session object,
// consider a new session
return session, nil
}
// Values found in session, this is not a new session
session.Values = m.copy(v)
session.IsNew = false
return session, nil
}
// Save adds a single session to the response.
// Set Options.MaxAge to -1 or call MaxAge(-1) before saving the session to delete all values in it.
func (m *MemStore) Save(r *http.Request, w http.ResponseWriter, s *sessions.Session) error {
var cookieValue string
if s.Options.MaxAge < 0 {
cookieValue = ""
m.cache.delete(s.ID)
for k := range s.Values {
delete(s.Values, k)
}
} else {
if s.ID == "" {
s.ID = strings.TrimRight(base32.StdEncoding.EncodeToString(securecookie.GenerateRandomKey(32)), "=")
}
encrypted, err := securecookie.EncodeMulti(s.Name(), s.ID, m.Codecs...)
if err != nil {
return err
}
cookieValue = encrypted
m.cache.setValue(s.ID, m.copy(s.Values))
}
http.SetCookie(w, sessions.NewCookie(s.Name(), cookieValue, s.Options))
return nil
}
// MaxAge sets the maximum age for the store and the underlying cookie
// implementation. Individual sessions can be deleted by setting Options.MaxAge
// = -1 for that session.
func (m *MemStore) MaxAge(age int) {
m.Options.MaxAge = age
// Set the maxAge for each securecookie instance.
for _, codec := range m.Codecs {
if sc, ok := codec.(*securecookie.SecureCookie); ok {
sc.MaxAge(age)
}
}
}
func (m *MemStore) copy(v valueType) valueType {
var buf bytes.Buffer
enc := gob.NewEncoder(&buf)
dec := gob.NewDecoder(&buf)
err := enc.Encode(v)
if err != nil {
panic(fmt.Errorf("could not copy memstore value. Encoding to gob failed: %v", err))
}
var value valueType
err = dec.Decode(&value)
if err != nil {
panic(fmt.Errorf("could not copy memstore value. Decoding from gob failed: %v", err))
}
return value
}