af04984 · skrepka · git.iko.soy

git.iko.soy/skrepka

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Fix messageMaxAge, messageIds DoS, maintenance auth timing leak, hexDigit overflow, and per-request prune overhead

af04984iko7 months ago

server.knot+41−26

compare with master

unifiedsplit

@@ -10,7 +10,7 @@ serverHost = "localhost:8080"

10federationSecret = "" -- must be set to enable federation

11maintenanceSecret = "" -- set to enable /maintenance/prune independently of federation

12federationScheme = "https://" -- scheme for federation HTTP calls

13−messageMaxAge = 86400000 -- 24 hours in milliseconds

13+messageMaxAge = 2592000000 -- 30 days in milliseconds

14maxPresenceTtl = 3600 -- max presence TTL from gossip in seconds

15maxPubkeyLen = 256

16maxBlobLen = 65536

@@ -60,6 +60,8 @@ type GossipEvent = {eventType: Text, pubkey: Text, server: Text, timestamp: Int,

61*ackedIds : [{messageId: Text, toKey: Text, ackedAt: Int}]

63+*lastPrunedAt : Int

64+

63-- ============================================

65-- ============================================

64-- Routes

66-- Routes

65-- ============================================

67-- ============================================

@@ -112,6 +114,7 @@ route Api = AuthApi | ClientApi | FederationApi | MaintenanceApi

112-- ============================================

114-- ============================================

113

115

114hexDigit = \n ->

116hexDigit = \n ->

117+ let n = if n < 0 then 0 else if n > 15 then 15 else n

115 if n == 0 then "0" else if n == 1 then "1" else if n == 2 then "2" else if n == 3 then "3"

118 if n == 0 then "0" else if n == 1 then "1" else if n == 2 then "2" else if n == 3 then "3"

116 else if n == 4 then "4" else if n == 5 then "5" else if n == 6 then "6" else if n == 7 then "7"

119 else if n == 4 then "4" else if n == 5 then "5" else if n == 6 then "6" else if n == 7 then "7"

117 else if n == 8 then "8" else if n == 9 then "9" else if n == 10 then "a" else if n == 11 then "b"

120 else if n == 8 then "8" else if n == 9 then "9" else if n == 10 then "a" else if n == 11 then "b"

@@ -327,8 +330,10 @@ verifyFederationAuth = \authorization ->

327 not (federationSecret == "") && safeCompare (extractToken authorization) federationSecret

330 not (federationSecret == "") && safeCompare (extractToken authorization) federationSecret

328

331

329verifyMaintenanceAuth = \authorization ->

332verifyMaintenanceAuth = \authorization ->

330− verifyFederationAuth authorization

331− || (not (maintenanceSecret == "") && safeCompare (extractToken authorization) maintenanceSecret)

333+ let token = extractToken authorization

334+ let fedOk = not (federationSecret == "") && safeCompare token federationSecret

335+ let maintOk = not (maintenanceSecret == "") && safeCompare token maintenanceSecret

336+ fedOk || maintOk

332

337

333clampTtl = \ttl -> if ttl < 1 then 1 else if ttl > maxPresenceTtl then maxPresenceTtl else ttl

338clampTtl = \ttl -> if ttl < 1 then 1 else if ttl > maxPresenceTtl then maxPresenceTtl else ttl

334

339

@@ -400,6 +405,14 @@ pruneExpired = \t -> do

400 yield q) == 0

405 yield q) == 0

401 yield p), peerServers: peerServersBefore}

406 yield p), peerServers: peerServersBefore}

402

407

408+maybePrune = \t -> do

409+ lastPruned <- *lastPrunedAt

410+ if t - lastPruned < 1000

411+ then yield {expiredLocal: [], peerServers: []}

412+ else do

413+ set *lastPrunedAt = t

414+ pruneExpired t

415+

403sendBatchedGossip = \peerServers allEvents ->

416sendBatchedGossip = \peerServers allEvents ->

404 if count allEvents == 0

417 if count allEvents == 0

405 then yield {}

418 then yield {}

@@ -461,7 +474,7 @@ serve = \req -> case req of

461 if valid

474 if valid

462 then do

475 then do

463 pruneResult <- atomic do

476 pruneResult <- atomic do

464− pr <- pruneExpired t

477+ pr <- maybePrune t

465 challenges <- *challenges

478 challenges <- *challenges

466 let existingCount = count (do c <- challenges; where c.pubkey == pubkey; yield c)

479 let existingCount = count (do c <- challenges; where c.pubkey == pubkey; yield c)

467 let oldestChallengeExpiry = fold (\acc c2 -> if c2.pubkey == pubkey && (acc == -1 || c2.expiresAt < acc) then c2.expiresAt else acc) -1 challenges

480 let oldestChallengeExpiry = fold (\acc c2 -> if c2.pubkey == pubkey && (acc == -1 || c2.expiresAt < acc) then c2.expiresAt else acc) -1 challenges

@@ -494,7 +507,7 @@ serve = \req -> case req of

494 token <- genToken

507 token <- genToken

495 let expiry = t + sessionExpiry

508 let expiry = t + sessionExpiry

496 result <- atomic do

509 result <- atomic do

497− pr <- pruneExpired t

510+ pr <- maybePrune t

498 challenges <- *challenges

511 challenges <- *challenges

499 sessions <- *sessions

512 sessions <- *sessions

500 presence <- *presence

513 presence <- *presence

@@ -582,7 +595,7 @@ serve = \req -> case req of

582 t <- now

595 t <- now

583 let token = extractToken authorization

596 let token = extractToken authorization

584 result <- atomic do

597 result <- atomic do

585− pr <- pruneExpired t

598+ pr <- maybePrune t

586 sessions <- *sessions

599 sessions <- *sessions

587 messages <- *messages

600 messages <- *messages

588 seqCounter <- *seqCounter

601 seqCounter <- *seqCounter

@@ -626,7 +639,7 @@ serve = \req -> case req of

626 msgId <- genToken

639 msgId <- genToken

627 let clampedTs = if timestamp > t then t else if timestamp < t - messageMaxAge then t - messageMaxAge else timestamp

640 let clampedTs = if timestamp > t then t else if timestamp < t - messageMaxAge then t - messageMaxAge else timestamp

628 result <- atomic do

641 result <- atomic do

629− pr <- pruneExpired t

642+ pr <- maybePrune t

630 sessions <- *sessions

643 sessions <- *sessions

631 messages <- *messages

644 messages <- *messages

632 presence <- *presence

645 presence <- *presence

@@ -696,15 +709,16 @@ serve = \req -> case req of

696

709

697 AckMessages {messageIds, authorization, respond} -> do

710 AckMessages {messageIds, authorization, respond} -> do

698 t <- now

711 t <- now

712+ let dedupedIds = if count messageIds > maxMessageIds then []

699− let dedupedIds = fold (\acc mid ->

713+ else fold (\acc mid ->

700− if mid == "" then acc

714+ if mid == "" then acc

701− else if count acc >= maxMessageIds then acc

715+ else if count acc >= maxMessageIds then acc

702− else if tooLong mid maxMessageIdLen then acc

716+ else if tooLong mid maxMessageIdLen then acc

703− else if not (isValidHex mid) then acc

717+ else if not (isValidHex mid) then acc

704− else if count (do a <- acc; where a == normalizeHex mid; yield a) > 0 then acc

718+ else if count (do a <- acc; where a == normalizeHex mid; yield a) > 0 then acc

705− else union acc [normalizeHex mid]) [] messageIds

719+ else union acc [normalizeHex mid]) [] messageIds

706 result <- atomic do

720 result <- atomic do

707− pr <- pruneExpired t

721+ pr <- maybePrune t

708 sessions <- *sessions

722 sessions <- *sessions

709 messages <- *messages

723 messages <- *messages

710 let session = lookupSession sessions (extractToken authorization) t

724 let session = lookupSession sessions (extractToken authorization) t

@@ -762,7 +776,7 @@ serve = \req -> case req of

762 let pubkey = if isValidHex pubkey then normalizeHex pubkey else pubkey

776 let pubkey = if isValidHex pubkey then normalizeHex pubkey else pubkey

763 t <- now

777 t <- now

764 result <- atomic do

778 result <- atomic do

765− pr <- pruneExpired t

779+ pr <- maybePrune t

766 sessions <- *sessions

780 sessions <- *sessions

767 presence <- *presence

781 presence <- *presence

768 let session = lookupSession sessions (extractToken authorization) t

782 let session = lookupSession sessions (extractToken authorization) t

@@ -854,7 +868,7 @@ serve = \req -> case req of

854 yield a)

868 yield a)

855 [e]) [] filteredOnline

869 [e]) [] filteredOnline

856 gossipResult <- atomic do

870 gossipResult <- atomic do

857− pr <- pruneExpired t

871+ pr <- maybePrune t

858 presence <- *presence

872 presence <- *presence

859 let fromServerTrusted = count (do p <- presence; where p.server == fromServer; yield p) > 0

873 let fromServerTrusted = count (do p <- presence; where p.server == fromServer; yield p) > 0

860 let trustedDeduped = do

874 let trustedDeduped = do

@@ -1042,7 +1056,7 @@ serve = \req -> case req of

1042 let validOrigin = not (originServer == "") && not (originServer == serverHostN) && not (tooLong originServer maxServerNameLen) && not (isBadServerName originServer)

1056 let validOrigin = not (originServer == "") && not (originServer == serverHostN) && not (tooLong originServer maxServerNameLen) && not (isBadServerName originServer)

1043 let clampedTs = if timestamp > t then t else if timestamp < t - messageMaxAge then t - messageMaxAge else timestamp

1057 let clampedTs = if timestamp > t then t else if timestamp < t - messageMaxAge then t - messageMaxAge else timestamp

1044 result <- atomic do

1058 result <- atomic do

1045− pr <- pruneExpired t

1059+ pr <- maybePrune t

1046 messages <- *messages

1060 messages <- *messages

1047 seqCounter <- *seqCounter

1061 seqCounter <- *seqCounter

1048 let seqTs = if t > seqCounter then t else seqCounter + 1

1062 let seqTs = if t > seqCounter then t else seqCounter + 1

@@ -1080,16 +1094,17 @@ serve = \req -> case req of

1080 let originServer = normalizeServerName originServer

1094 let originServer = normalizeServerName originServer

1081 t <- now

1095 t <- now

1082 let authorized = verifyFederationAuth authorization

1096 let authorized = verifyFederationAuth authorization

1097+ let dedupedIds = if count messageIds > maxMessageIds then []

1083− let dedupedIds = fold (\acc mid ->

1098+ else fold (\acc mid ->

1084− if mid == "" then acc

1099+ if mid == "" then acc

1085− else if count acc >= maxMessageIds then acc

1100+ else if count acc >= maxMessageIds then acc

1086− else if tooLong mid maxMessageIdLen then acc

1101+ else if tooLong mid maxMessageIdLen then acc

1087− else if not (isValidHex mid) then acc

1102+ else if not (isValidHex mid) then acc

1088− else if count (do a <- acc; where a == normalizeHex mid; yield a) > 0 then acc

1103+ else if count (do a <- acc; where a == normalizeHex mid; yield a) > 0 then acc

1089− else union acc [normalizeHex mid]) [] messageIds

1104+ else union acc [normalizeHex mid]) [] messageIds

1090 let validAckFields = authorized && originServer == serverHostN && not (fromServer == "") && not (fromServer == serverHostN) && not (tooLong fromServer maxServerNameLen) && not (isBadServerName fromServer)

1105 let validAckFields = authorized && originServer == serverHostN && not (fromServer == "") && not (fromServer == serverHostN) && not (tooLong fromServer maxServerNameLen) && not (isBadServerName fromServer)

1091 pruneResult <- atomic do

1106 pruneResult <- atomic do

1092− pr <- pruneExpired t

1107+ pr <- maybePrune t

1093 forwards <- *forwards

1108 forwards <- *forwards

1094 let validAck = validAckFields

1109 let validAck = validAckFields

1095 let forwardsToRemove = do

1110 let forwardsToRemove = do