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|
local type = type
local concat = table.concat
local strategy = {}
function strategy.load(session, cookie, key, keep_lock)
local storage = session.storage
local id = cookie.id
local id_encoded = session.encoder.encode(id)
local data, err, tag
if storage.open then
data, err = storage:open(id_encoded, keep_lock)
if not data then
return nil, err or "cookie data was not found"
end
else
data = cookie.data
end
local expires = cookie.expires
local usebefore = cookie.usebefore
local hash = cookie.hash
if not key then
key = concat{ id, expires, usebefore }
end
local hkey = session.hmac(session.secret, key)
data, err, tag = session.cipher:decrypt(data, hkey, id, session.key, hash)
if not data then
if storage.close then
storage:close(id_encoded)
end
return nil, err or "unable to decrypt data"
end
if tag then
if tag ~= hash then
if storage.close then
storage:close(id_encoded)
end
return nil, "cookie has invalid tag"
end
else
local input = concat{ key, data, session.key }
if session.hmac(hkey, input) ~= hash then
if storage.close then
storage:close(id_encoded)
end
return nil, "cookie has invalid signature"
end
end
data, err = session.compressor:decompress(data)
if not data then
if storage.close then
storage:close(id_encoded)
end
return nil, err or "unable to decompress data"
end
data, err = session.serializer.deserialize(data)
if not data then
if storage.close then
storage:close(id_encoded)
end
return nil, err or "unable to deserialize data"
end
session.id = id
session.expires = expires
session.usebefore = usebefore
session.data = type(data) == "table" and data or {}
session.present = true
return true
end
function strategy.open(session, cookie, keep_lock)
return strategy.load(session, cookie, nil, keep_lock)
end
function strategy.start(session)
local storage = session.storage
if not storage.start then
return true
end
local id_encoded = session.encoder.encode(session.id)
local ok, err = storage:start(id_encoded)
if not ok then
return nil, err or "unable to start session"
end
return true
end
function strategy.modify(session, action, close, key)
local id = session.id
local id_encoded = session.encoder.encode(id)
local storage = session.storage
local expires = session.expires
local usebefore = session.usebefore
local ttl = expires - session.now
if ttl <= 0 then
if storage.close then
storage:close(id_encoded)
end
return nil, "session is already expired"
end
if not key then
key = concat{ id, expires, usebefore }
end
local data, err = session.serializer.serialize(session.data)
if not data then
if close and storage.close then
storage:close(id_encoded)
end
return nil, err or "unable to serialize data"
end
data, err = session.compressor:compress(data)
if not data then
if close and storage.close then
storage:close(id_encoded)
end
return nil, err or "unable to compress data"
end
local hkey = session.hmac(session.secret, key)
local encrypted_data, tag
encrypted_data, err, tag = session.cipher:encrypt(data, hkey, id, session.key)
if not encrypted_data then
if close and storage.close then
storage:close(id_encoded)
end
return nil, err
end
local hash
if tag then
hash = tag
else
-- it would be better to calculate signature from encrypted_data,
-- but this is kept for backward compatibility
hash = session.hmac(hkey, concat{ key, data, session.key })
end
if action == "save" and storage.save then
local ok
ok, err = storage:save(id_encoded, ttl, encrypted_data, close)
if not ok then
return nil, err
end
elseif close and storage.close then
local ok
ok, err = storage:close(id_encoded)
if not ok then
return nil, err
end
end
if usebefore then
expires = expires .. ":" .. usebefore
end
hash = session.encoder.encode(hash)
local cookie
if storage.save then
cookie = concat({ id_encoded, expires, hash }, "|")
else
local encoded_data = session.encoder.encode(encrypted_data)
cookie = concat({ id_encoded, expires, encoded_data, hash }, "|")
end
return cookie
end
function strategy.touch(session, close)
return strategy.modify(session, "touch", close)
end
function strategy.save(session, close)
return strategy.modify(session, "save", close)
end
function strategy.destroy(session)
local id = session.id
if id then
local storage = session.storage
if storage.destroy then
return storage:destroy(session.encoder.encode(id))
elseif storage.close then
return storage:close(session.encoder.encode(id))
end
end
return true
end
function strategy.close(session)
local id = session.id
if id then
local storage = session.storage
if storage.close then
return storage:close(session.encoder.encode(id))
end
end
return true
end
return strategy
|
