b157c1c · skrepka · git.iko.soy

git.iko.soy/skrepka

Fix serverHost normalization mismatch, forward retry data loss, safeCompare timing leak, and SSRF gaps

- Normalize serverHost via serverHostN to prevent case/trailing-dot mismatches when comparing against incoming federation server names - Store message body in forward records so Prune can retry forwards even after the client acks and deletes the original message - Fix safeCompareLoop to iterate max(len(a), len(b)) instead of len(b), preventing timing-based secret length disclosure - Replace blanket numeric IP ban with targeted checks: block decimal integer IPs plus multicast (224-239) and reserved (240-255) ranges, allowing dotted-decimal public IPs for federation - Remove blocking sleep 500 in sendToEach retry path

commitb157c1c53a69f77c1675fce0522baf8b4124cd24 authoriko <mail@iko.soy> dateMon 30 Mar 2026, 11:38 (7 months ago) parent574bd2f

1 file changed+47−36

compare with master

unifiedsplit

server.knot+47−36

server.knot+47−36

@@ -55,7 +55,7 @@ type GossipEvent = {eventType: Text, pubkey: Text, server: Text, timestamp: Int,

5555

5656*seqCounter : Int

5757

58−*forwards : [{messageId: Text, toServer: Text, createdAt: Int}]

58+*forwards : [{messageId: Text, toServer: Text, createdAt: Int, toKey: Text, fromKey: Text, encryptedBlob: Text, timestamp: Int}]

5959

6060*ackedIds : [{messageId: Text, toKey: Text, ackedAt: Int}]

6161

@@ -221,6 +221,12 @@ isAllDigitsOrDotsUntilColonOrEnd = \s ->

221221 else if isDigitChar (take 1 s) || take 1 s == "." then isAllDigitsOrDotsUntilColonOrEnd (drop 1 s)

222222 else False {}

223223

224+isAllDigitsUntilColonOrEnd = \s ->

225+ if s == "" then True {}

226+ else if take 1 s == ":" then True {}

227+ else if isDigitChar (take 1 s) then isAllDigitsUntilColonOrEnd (drop 1 s)

228+ else False {}

229+

224230toLowerChar = \c ->

225231 if c == "A" then "a" else if c == "B" then "b" else if c == "C" then "c"

226232 else if c == "D" then "d" else if c == "E" then "e" else if c == "F" then "f"

@@ -250,6 +256,8 @@ stripTrailingDot = \s ->

250256

251257normalizeServerName = \s -> toLower (stripTrailingDot s)

252258

259+serverHostN = normalizeServerName serverHost

260+

253261containsLocalhostSuffix = \s ->

254262 if s == "" then False {}

255263 else if take 10 s == ".localhost" && (drop 10 s == "" || take 1 (drop 10 s) == ":") then True {}

@@ -281,7 +289,15 @@ isBadServerName = \s ->

281289 || containsMultipleColons sn

282290 || hasOctalOctet sn

283291 || hasHexPrefix sn

284− || (isDigitChar (take 1 sn) && isAllDigitsOrDotsUntilColonOrEnd sn)

292+ || (isDigitChar (take 1 sn) && isAllDigitsUntilColonOrEnd sn)

293+ || take 4 sn == "224." || take 4 sn == "225." || take 4 sn == "226." || take 4 sn == "227."

294+ || take 4 sn == "228." || take 4 sn == "229." || take 4 sn == "230." || take 4 sn == "231."

295+ || take 4 sn == "232." || take 4 sn == "233." || take 4 sn == "234." || take 4 sn == "235."

296+ || take 4 sn == "236." || take 4 sn == "237." || take 4 sn == "238." || take 4 sn == "239."

297+ || take 4 sn == "240." || take 4 sn == "241." || take 4 sn == "242." || take 4 sn == "243."

298+ || take 4 sn == "244." || take 4 sn == "245." || take 4 sn == "246." || take 4 sn == "247."

299+ || take 4 sn == "248." || take 4 sn == "249." || take 4 sn == "250." || take 4 sn == "251."

300+ || take 4 sn == "252." || take 4 sn == "253." || take 4 sn == "254." || take 4 sn == "255."

285301

286302lookupSession = \sessions token t ->

287303 single (do

@@ -312,8 +328,8 @@ verifyMaintenanceAuth = \authorization ->

312328clampTtl = \ttl -> if ttl < 1 then 1 else if ttl > maxPresenceTtl then maxPresenceTtl else ttl

313329

314330safeCompareLoop = \s1 s2 result ->

315− if s2 == ""

316− then result + (if s1 == "" then 0 else 1)

331+ if s1 == "" && s2 == ""

332+ then result

317333 else safeCompareLoop (drop 1 s1) (drop 1 s2) (result + (if take 1 s1 == take 1 s2 then 0 else 1))

318334

319335safeCompare = \a b ->

@@ -330,7 +346,6 @@ sendToEach = \servers action ->

330346 else do

331347 catch (action server) (\err -> do

332348 println ("federation: error reaching " ++ server ++ ", retrying: " ++ show err)

333− sleep 500

334349 catch (action server) (\err2 -> do

335350 println ("federation: retry failed for " ++ server ++ ": " ++ show err2)

336351 yield {}))

@@ -349,7 +364,7 @@ pruneExpired = \t -> do

349364 yield s

350365 presenceBefore <- *presence

351366 let peerServersBefore = fold (\acc p ->

352− if p.server == serverHost then acc

367+ if p.server == serverHostN then acc

353368 else if count (do a <- acc; where a == p.server; yield a) > 0 then acc

354369 else union acc [p.server]) [] presenceBefore

355370 let presenceAfter = do

@@ -375,11 +390,11 @@ pruneExpired = \t -> do

375390 yield {expiredLocal: (do

376391 p <- presenceBefore

377392 where p.expiresAt <= t

378− where p.server == serverHost

393+ where p.server == serverHostN

379394 where count (do

380395 q <- presenceAfter

381396 where q.pubkey == p.pubkey

382− where q.server == serverHost

397+ where q.server == serverHostN

383398 yield q) == 0

384399 yield p), peerServers: peerServersBefore}

385400

@@ -397,7 +412,7 @@ sendBatchedGossip = \peerServers allEvents ->

397412 sendToEach peerServers (\server ->

398413 fetch (federationScheme ++ server) (RecvGossip {

399414 authorization: "Bearer " ++ federationSecret,

400− events: batch, hopsRemaining: 2, fromServer: serverHost}))

415+ events: batch, hopsRemaining: 2, fromServer: serverHostN}))

401416 sendBatchedGossip peerServers rest

402417

403418broadcastOfflineGossip = \t peerServers expiredLocal -> do

@@ -408,7 +423,7 @@ broadcastOfflineGossip = \t peerServers expiredLocal -> do

408423 then do

409424 let gossipEvents = do

410425 e <- expiredEntries

411− yield {eventType: "offline", pubkey: e.pubkey, server: serverHost, timestamp: t, ttl: e.ttl}

426+ yield {eventType: "offline", pubkey: e.pubkey, server: serverHostN, timestamp: t, ttl: e.ttl}

412427 sendBatchedGossip peerServers gossipEvents

413428 else yield {}

414429

@@ -423,7 +438,7 @@ retryPendingForwards = \pending ->

423438 else do

424439 catch (fetch (federationScheme ++ f.toServer) (ForwardMessage {

425440 toKey: f.toKey, fromKey: f.fromKey, encryptedBlob: f.encryptedBlob,

426− timestamp: f.timestamp, originServer: serverHost, messageId: f.messageId,

441+ timestamp: f.timestamp, originServer: serverHostN, messageId: f.messageId,

427442 authorization: "Bearer " ++ federationSecret})) (\err ->

428443 println ("prune: retry forward to " ++ f.toServer ++ " failed: " ++ show err))

429444 retryPendingForwards rest

@@ -525,7 +540,7 @@ serve = \req -> case req of

525540 else sessions

526541 let presenceWithout = do

527542 p <- presence

528− where not (p.pubkey == pubkey && p.server == serverHost)

543+ where not (p.pubkey == pubkey && p.server == serverHostN)

529544 yield p

530545 let oldestPresenceExp = fold (\acc p -> if acc == -1 || p.expiresAt < acc then p.expiresAt else acc) -1 presenceWithout

531546 let presenceEvicted = if count presenceWithout >= maxPresenceEntries && oldestPresenceExp >= 0

@@ -535,12 +550,12 @@ serve = \req -> case req of

535550 else {removed: acc.removed, items: union acc.items [p]}) {removed: False {}, items: []} presenceWithout).items

536551 else presenceWithout

537552 let updatedPresence = if sigValid

538− then union presenceEvicted [{pubkey: pubkey, server: serverHost, expiresAt: expiry, timestamp: t}]

553+ then union presenceEvicted [{pubkey: pubkey, server: serverHostN, expiresAt: expiry, timestamp: t}]

539554 else presence

540555 set *presence = updatedPresence

541556 let peerServers = if sigValid && not (federationSecret == "")

542557 then fold (\acc p ->

543− if p.server == serverHost then acc

558+ if p.server == serverHostN then acc

544559 else if count (do a <- acc; where a == p.server; yield a) > 0 then acc

545560 else union acc [p.server]) [] updatedPresence

546561 else []

@@ -552,7 +567,7 @@ serve = \req -> case req of

552567 then sendToEach result.peerServers (\server ->

553568 fetch (federationScheme ++ server) (RecvGossip {

554569 authorization: "Bearer " ++ federationSecret,

555− events: [{eventType: "online", pubkey: pubkey, server: serverHost, timestamp: t, ttl: onlineGossipTtl}], hopsRemaining: 2, fromServer: serverHost}))

570+ events: [{eventType: "online", pubkey: pubkey, server: serverHostN, timestamp: t, ttl: onlineGossipTtl}], hopsRemaining: 2, fromServer: serverHostN}))

556571 else yield {}

557572 broadcastOfflineGossip t result.offlinePeers (do

558573 p <- result.expiredLocal

@@ -635,7 +650,7 @@ serve = \req -> case req of

635650 Just {value: _} -> count (do

636651 p <- presence

637652 where p.pubkey == to

638− where p.server == serverHost

653+ where p.server == serverHostN

639654 where p.expiresAt > t

640655 yield p) > 0

641656 let remoteServers = case session of

@@ -643,7 +658,7 @@ serve = \req -> case req of

643658 Just {value: _} -> do

644659 p <- presence

645660 where p.pubkey == to

646− where not (p.server == serverHost)

661+ where not (p.server == serverHostN)

647662 where p.expiresAt > t

648663 yield p.server

649664 let fromKey = case session of

@@ -658,7 +673,7 @@ serve = \req -> case req of

658673 forwards <- *forwards

659674 let forwardsAtCapacity = count forwards >= maxForwardsEntries

660675 set *forwards = if shouldInsert && not forwardsAtCapacity && count remoteServers > 0

661− then union forwards (do s <- remoteServers; yield {messageId: msgId, toServer: s, createdAt: t})

676+ then union forwards (do s <- remoteServers; yield {messageId: msgId, toServer: s, createdAt: t, toKey: to, fromKey: fromKey, encryptedBlob: encryptedBlob, timestamp: clampedTs})

662677 else forwards

663678 yield {status: status, remoteServers: remoteServers, fromKey: fromKey, expiredLocal: pr.expiredLocal, peerServers: pr.peerServers, forwardsAtCapacity: forwardsAtCapacity}

664679 let finalStatus = if result.status == "federated" && federationSecret == "" then "queued" else result.status

@@ -667,7 +682,7 @@ serve = \req -> case req of

667682 then sendToEach result.remoteServers (\server ->

668683 fetch (federationScheme ++ server) (ForwardMessage {

669684 toKey: to, fromKey: result.fromKey, encryptedBlob: encryptedBlob,

670− timestamp: clampedTs, originServer: serverHost, messageId: msgId,

685+ timestamp: clampedTs, originServer: serverHostN, messageId: msgId,

671686 authorization: "Bearer " ++ federationSecret}))

672687 else yield {}

673688 if result.forwardsAtCapacity && count result.remoteServers > 0 && not (result.status == "unauthorized") && not (result.status == "invalid")

@@ -703,7 +718,7 @@ serve = \req -> case req of

703718 let ackedFederated = do

704719 m <- ackedMessages

705720 where not (m.originServer == "")

706− where not (m.originServer == serverHost)

721+ where not (m.originServer == serverHostN)

707722 yield {messageId: m.messageId, toKey: m.toKey, ackedAt: t}

708723 ackedIds <- *ackedIds

709724 set *ackedIds = union ackedIds ackedFederated

@@ -714,7 +729,7 @@ serve = \req -> case req of

714729 let fedMessages = do

715730 m <- result.ackedMessages

716731 where not (m.originServer == "")

717− where not (m.originServer == serverHost)

732+ where not (m.originServer == serverHostN)

718733 yield m

719734 let originServers = fold (\acc m ->

720735 if count (do a <- acc; where a == m.originServer; yield a) > 0 then acc

@@ -725,7 +740,7 @@ serve = \req -> case req of

725740 fetch (federationScheme ++ server) (FederationAck {

726741 authorization: "Bearer " ++ federationSecret,

727742 messageIds: (do m <- fedMessages; where m.originServer == server; yield m.messageId),

728− originServer: server, fromServer: serverHost}))

743+ originServer: server, fromServer: serverHostN}))

729744 else yield {}

730745 broadcastOfflineGossip t result.peerServers result.expiredLocal

731746

@@ -753,7 +768,7 @@ serve = \req -> case req of

753768 then ""

754769 else case single (do

755770 p <- valid

756− where p.server == serverHost

771+ where p.server == serverHostN

757772 yield p) of

758773 Just {value: p} -> p.server

759774 Nothing {} -> (fold (\acc p -> if p.expiresAt > acc.best then {server: p.server, best: p.expiresAt} else acc) {server: "", best: 0} valid).server

@@ -766,7 +781,7 @@ serve = \req -> case req of

766781 let authorized = verifyFederationAuth authorization

767782 let cappedHops = if hopsRemaining > 5 then 5 else hopsRemaining

768783 let fromServer = normalizeServerName fromServer

769− let validRequest = authorized && cappedHops >= 1 && not (fromServer == "") && not (fromServer == serverHost) && not (tooLong fromServer maxServerNameLen) && not (isBadServerName fromServer) && count events <= maxGossipEvents

784+ let validRequest = authorized && cappedHops >= 1 && not (fromServer == "") && not (fromServer == serverHostN) && not (tooLong fromServer maxServerNameLen) && not (isBadServerName fromServer) && count events <= maxGossipEvents

770785 let onlineEntries = do

771786 e <- events

772787 where validRequest

@@ -777,7 +792,7 @@ serve = \req -> case req of

777792 where not (tooLong e.server maxServerNameLen)

778793 where not (isBadServerName e.server)

779794 where isValidHex e.pubkey

780− where not (normalizeServerName e.server == serverHost)

795+ where not (normalizeServerName e.server == serverHostN)

781796 where e.timestamp <= t + clockSkewTolerance

782797 where e.timestamp + (clampTtl e.ttl) * 1000 > t

783798 yield {pubkey: normalizeHex e.pubkey, server: normalizeServerName e.server, expiresAt: e.timestamp + (clampTtl e.ttl) * 1000, timestamp: e.timestamp}

@@ -791,7 +806,7 @@ serve = \req -> case req of

791806 where not (tooLong e.server maxServerNameLen)

792807 where not (isBadServerName e.server)

793808 where isValidHex e.pubkey

794− where not (normalizeServerName e.server == serverHost)

809+ where not (normalizeServerName e.server == serverHostN)

795810 where e.timestamp <= t + clockSkewTolerance

796811 where t - e.timestamp < (clampTtl e.ttl) * 1000

797812 yield {pubkey: normalizeHex e.pubkey, server: normalizeServerName e.server, timestamp: e.timestamp}

@@ -954,7 +969,7 @@ serve = \req -> case req of

954969 else presence

955970 set *presence = finalPresence

956971 let gossipPeerServers = fold (\acc p ->

957− if p.server == serverHost then acc

972+ if p.server == serverHostN then acc

958973 else if count (do a <- acc; where a == p.server; yield a) > 0 then acc

959974 else union acc [p.server]) [] finalPresence

960975 yield {appliedKeys: (if withinCapacity then union appliedOnline appliedOffline else union appliedOnlineUpdates appliedOffline), expiredLocal: pr.expiredLocal, peerServers: pr.peerServers, gossipPeerServers: gossipPeerServers, withinCapacity: withinCapacity}

@@ -968,7 +983,7 @@ serve = \req -> case req of

968983 where not (tooLong e.server maxServerNameLen)

969984 where not (isBadServerName e.server)

970985 where isValidHex e.pubkey

971− where not (normalizeServerName e.server == serverHost)

986+ where not (normalizeServerName e.server == serverHostN)

972987 where e.timestamp <= t + clockSkewTolerance

973988 where e.timestamp + (clampTtl e.ttl) * 1000 > t

974989 where not (e.eventType == "online" && count (do

@@ -998,7 +1013,7 @@ serve = \req -> case req of

9981013 sendToEach targets (\server ->

9991014 fetch (federationScheme ++ server) (RecvGossip {

10001015 authorization: "Bearer " ++ federationSecret,

1001− events: effectiveEvents, hopsRemaining: cappedHops - 1, fromServer: serverHost}))

1016+ events: effectiveEvents, hopsRemaining: cappedHops - 1, fromServer: serverHostN}))

10021017 else yield {}

10031018 broadcastOfflineGossip t gossipResult.peerServers gossipResult.expiredLocal

10041019

@@ -1011,7 +1026,7 @@ serve = \req -> case req of

10111026 let originServer = normalizeServerName originServer

10121027 t <- now

10131028 let authorized = verifyFederationAuth authorization

1014− let validOrigin = not (originServer == "") && not (originServer == serverHost) && not (tooLong originServer maxServerNameLen) && not (isBadServerName originServer)

1029+ let validOrigin = not (originServer == "") && not (originServer == serverHostN) && not (tooLong originServer maxServerNameLen) && not (isBadServerName originServer)

10151030 let clampedTs = if timestamp > t then t else if timestamp < t - messageMaxAge then t - messageMaxAge else timestamp

10161031 result <- atomic do

10171032 pr <- pruneExpired t

@@ -1059,7 +1074,7 @@ serve = \req -> case req of

10591074 else if not (isValidHex mid) then acc

10601075 else if count (do a <- acc; where a == normalizeHex mid; yield a) > 0 then acc

10611076 else union acc [normalizeHex mid]) [] messageIds

1062− let validAckFields = authorized && originServer == serverHost && not (fromServer == "") && not (fromServer == serverHost) && not (tooLong fromServer maxServerNameLen) && not (isBadServerName fromServer)

1077+ let validAckFields = authorized && originServer == serverHostN && not (fromServer == "") && not (fromServer == serverHostN) && not (tooLong fromServer maxServerNameLen) && not (isBadServerName fromServer)

10631078 pruneResult <- atomic do

10641079 pr <- pruneExpired t

10651080 forwards <- *forwards

@@ -1085,13 +1100,9 @@ serve = \req -> case req of

10851100 result <- atomic do

10861101 pr <- pruneExpired t

10871102 forwards <- *forwards

1088− messages <- *messages

10891103 let pendingForwards = do

10901104 f <- forwards

1091− m <- messages

1092− where m.messageId == f.messageId

1093− where m.originServer == ""

1094− yield {toServer: f.toServer, toKey: m.toKey, fromKey: m.fromKey, encryptedBlob: m.encryptedBlob, timestamp: m.timestamp, messageId: m.messageId}

1105+ yield {toServer: f.toServer, toKey: f.toKey, fromKey: f.fromKey, encryptedBlob: f.encryptedBlob, timestamp: f.timestamp, messageId: f.messageId}

10951106 yield {expiredLocal: pr.expiredLocal, peerServers: pr.peerServers, pendingForwards: pendingForwards}

10961107 respond {ok: True {}}

10971108 broadcastOfflineGossip t result.peerServers result.expiredLocal