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authorwolfbeast <mcwerewolf@gmail.com>2018-04-25 23:08:37 +0200
committerwolfbeast <mcwerewolf@gmail.com>2018-04-25 23:08:37 +0200
commit42f8488a5f66d7c1e5324bd1755d7f693b16ee97 (patch)
tree54c7d2a62c4ea34b1250b5362c8e6f89d03f1a02 /security/nss/lib/ssl/tls13replay.c
parent681c39a0ecc84fc918b2bec72cc69ad27d39903a (diff)
parent6c3f95480a191ce432ddfb2aa400a6d70c4884a8 (diff)
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Merge branch 'master' into Basilisk-releasev2018.04.26
Diffstat (limited to 'security/nss/lib/ssl/tls13replay.c')
-rw-r--r--security/nss/lib/ssl/tls13replay.c276
1 files changed, 0 insertions, 276 deletions
diff --git a/security/nss/lib/ssl/tls13replay.c b/security/nss/lib/ssl/tls13replay.c
deleted file mode 100644
index b090f9bca..000000000
--- a/security/nss/lib/ssl/tls13replay.c
+++ /dev/null
@@ -1,276 +0,0 @@
-/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
-/*
- * Anti-replay measures for TLS 1.3.
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-#include "nss.h" /* for NSS_RegisterShutdown */
-#include "nssilock.h" /* for PZMonitor */
-#include "pk11pub.h"
-#include "prinit.h" /* for PR_CallOnce */
-#include "prmon.h"
-#include "prtime.h"
-#include "secerr.h"
-#include "ssl.h"
-#include "sslbloom.h"
-#include "sslimpl.h"
-#include "tls13hkdf.h"
-
-static struct {
- /* Used to ensure that we only initialize the cleanup function once. */
- PRCallOnceType init;
- /* Used to serialize access to the filters. */
- PZMonitor *lock;
- /* The filters, use of which alternates. */
- sslBloomFilter filters[2];
- /* Which of the two filters is active (0 or 1). */
- PRUint8 current;
- /* The time that we will next update. */
- PRTime nextUpdate;
- /* The width of the window; i.e., the period of updates. */
- PRTime window;
- /* This key ensures that the bloom filter index is unpredictable. */
- PK11SymKey *key;
-} ssl_anti_replay;
-
-/* Clear the current state and free any resources we allocated. The signature
- * here is odd to allow this to be called during shutdown. */
-static SECStatus
-tls13_AntiReplayReset(void *appData, void *nssData)
-{
- if (ssl_anti_replay.key) {
- PK11_FreeSymKey(ssl_anti_replay.key);
- ssl_anti_replay.key = NULL;
- }
- if (ssl_anti_replay.lock) {
- PZ_DestroyMonitor(ssl_anti_replay.lock);
- ssl_anti_replay.lock = NULL;
- }
- sslBloom_Destroy(&ssl_anti_replay.filters[0]);
- sslBloom_Destroy(&ssl_anti_replay.filters[1]);
- return SECSuccess;
-}
-
-static PRStatus
-tls13_AntiReplayInit(void)
-{
- SECStatus rv = NSS_RegisterShutdown(tls13_AntiReplayReset, NULL);
- if (rv != SECSuccess) {
- return PR_FAILURE;
- }
- return PR_SUCCESS;
-}
-
-static SECStatus
-tls13_AntiReplayKeyGen()
-{
- PRUint8 buf[32];
- SECItem keyItem = { siBuffer, buf, sizeof(buf) };
- PK11SlotInfo *slot;
- SECStatus rv;
-
- slot = PK11_GetInternalSlot();
- if (!slot) {
- PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
- return SECFailure;
- }
- rv = PK11_GenerateRandomOnSlot(slot, buf, sizeof(buf));
- if (rv != SECSuccess) {
- goto loser;
- }
-
- ssl_anti_replay.key = PK11_ImportSymKey(slot, CKM_NSS_HKDF_SHA256,
- PK11_OriginUnwrap, CKA_DERIVE,
- &keyItem, NULL);
- if (!ssl_anti_replay.key) {
- goto loser;
- }
-
- PK11_FreeSlot(slot);
- return SECSuccess;
-
-loser:
- PK11_FreeSlot(slot);
- return SECFailure;
-}
-
-/* Set a limit on the combination of number of hashes and bits in each hash. */
-#define SSL_MAX_BLOOM_FILTER_SIZE 64
-
-/*
- * The structures created by this function can be called concurrently on
- * multiple threads if the server is multi-threaded. A monitor is used to
- * ensure that only one thread can access the structures that change over time,
- * but no such guarantee is provided for configuration data.
- *
- * Functions that read from static configuration data depend on there being a
- * memory barrier between the setup and use of this function.
- */
-SECStatus
-SSLExp_SetupAntiReplay(PRTime window, unsigned int k, unsigned int bits)
-{
- SECStatus rv;
-
- if (k == 0 || bits == 0) {
- PORT_SetError(SEC_ERROR_INVALID_ARGS);
- return SECFailure;
- }
- if ((k * (bits + 7) / 8) > SSL_MAX_BLOOM_FILTER_SIZE) {
- PORT_SetError(SEC_ERROR_INVALID_ARGS);
- return SECFailure;
- }
-
- if (PR_SUCCESS != PR_CallOnce(&ssl_anti_replay.init,
- tls13_AntiReplayInit)) {
- PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
- return SECFailure;
- }
-
- (void)tls13_AntiReplayReset(NULL, NULL);
-
- ssl_anti_replay.lock = PZ_NewMonitor(nssILockSSL);
- if (!ssl_anti_replay.lock) {
- goto loser; /* Code already set. */
- }
-
- rv = tls13_AntiReplayKeyGen();
- if (rv != SECSuccess) {
- goto loser; /* Code already set. */
- }
-
- rv = sslBloom_Init(&ssl_anti_replay.filters[0], k, bits);
- if (rv != SECSuccess) {
- goto loser; /* Code already set. */
- }
- rv = sslBloom_Init(&ssl_anti_replay.filters[1], k, bits);
- if (rv != SECSuccess) {
- goto loser; /* Code already set. */
- }
- /* When starting out, ensure that 0-RTT is not accepted until the window is
- * updated. A ClientHello might have been accepted prior to a restart. */
- sslBloom_Fill(&ssl_anti_replay.filters[1]);
-
- ssl_anti_replay.current = 0;
- ssl_anti_replay.nextUpdate = ssl_TimeUsec() + window;
- ssl_anti_replay.window = window;
- return SECSuccess;
-
-loser:
- (void)tls13_AntiReplayReset(NULL, NULL);
- return SECFailure;
-}
-
-/* This is exposed to tests. Though it could, this doesn't take the lock on the
- * basis that those tests use thread confinement. */
-void
-tls13_AntiReplayRollover(PRTime now)
-{
- ssl_anti_replay.current ^= 1;
- ssl_anti_replay.nextUpdate = now + ssl_anti_replay.window;
- sslBloom_Zero(ssl_anti_replay.filters + ssl_anti_replay.current);
-}
-
-static void
-tls13_AntiReplayUpdate()
-{
- PRTime now;
-
- PR_ASSERT_CURRENT_THREAD_IN_MONITOR(ssl_anti_replay.lock);
-
- now = ssl_TimeUsec();
- if (now < ssl_anti_replay.nextUpdate) {
- return;
- }
-
- tls13_AntiReplayRollover(now);
-}
-
-PRBool
-tls13_InWindow(const sslSocket *ss, const sslSessionID *sid)
-{
- PRInt32 timeDelta;
-
- /* Calculate the difference between the client's view of the age of the
- * ticket (in |ss->xtnData.ticketAge|) and the server's view, which we now
- * calculate. The result should be close to zero. timeDelta is signed to
- * make the comparisons below easier. */
- timeDelta = ss->xtnData.ticketAge -
- ((ssl_TimeUsec() - sid->creationTime) / PR_USEC_PER_MSEC);
-
- /* Only allow the time delta to be at most half of our window. This is
- * symmetrical, though it doesn't need to be; this assumes that clock errors
- * on server and client will tend to cancel each other out.
- *
- * There are two anti-replay filters that roll over each window. In the
- * worst case, immediately after a rollover of the filters, we only have a
- * single window worth of recorded 0-RTT attempts. Thus, the period in
- * which we can accept 0-RTT is at most one window wide. This uses PR_ABS()
- * and half the window so that the first attempt can be up to half a window
- * early and then replays will be caught until the attempts are half a
- * window late.
- *
- * For example, a 0-RTT attempt arrives early, but near the end of window 1.
- * The attempt is then recorded in window 1. Rollover to window 2 could
- * occur immediately afterwards. Window 1 is still checked for new 0-RTT
- * attempts for the remainder of window 2. Therefore, attempts to replay
- * are detected because the value is recorded in window 1. When rollover
- * occurs again, window 1 is erased and window 3 instated. If we allowed an
- * attempt to be late by more than half a window, then this check would not
- * prevent the same 0-RTT attempt from being accepted during window 1 and
- * later window 3.
- */
- return PR_ABS(timeDelta) < (ssl_anti_replay.window / 2);
-}
-
-/* Checks for a duplicate in the two filters we have. Performs maintenance on
- * the filters as a side-effect. This only detects a probable replay, it's
- * possible that this will return true when the 0-RTT attempt is not genuinely a
- * replay. In that case, we reject 0-RTT unnecessarily, but that's OK because
- * no client expects 0-RTT to work every time. */
-PRBool
-tls13_IsReplay(const sslSocket *ss, const sslSessionID *sid)
-{
- PRBool replay;
- unsigned int size;
- PRUint8 index;
- SECStatus rv;
- static const char *label = "tls13 anti-replay";
- PRUint8 buf[SSL_MAX_BLOOM_FILTER_SIZE];
-
- /* If SSL_SetupAntiReplay hasn't been called, then treat all attempts at
- * 0-RTT as a replay. */
- if (!ssl_anti_replay.init.initialized) {
- return PR_TRUE;
- }
-
- if (!tls13_InWindow(ss, sid)) {
- return PR_TRUE;
- }
-
- size = ssl_anti_replay.filters[0].k *
- (ssl_anti_replay.filters[0].bits + 7) / 8;
- PORT_Assert(size <= SSL_MAX_BLOOM_FILTER_SIZE);
- rv = tls13_HkdfExpandLabelRaw(ssl_anti_replay.key, ssl_hash_sha256,
- ss->xtnData.pskBinder.data,
- ss->xtnData.pskBinder.len,
- label, strlen(label),
- buf, size);
- if (rv != SECSuccess) {
- return PR_TRUE;
- }
-
- PZ_EnterMonitor(ssl_anti_replay.lock);
- tls13_AntiReplayUpdate();
-
- index = ssl_anti_replay.current;
- replay = sslBloom_Add(&ssl_anti_replay.filters[index], buf);
- if (!replay) {
- replay = sslBloom_Check(&ssl_anti_replay.filters[index ^ 1],
- buf);
- }
-
- PZ_ExitMonitor(ssl_anti_replay.lock);
- return replay;
-}