Merge pull request #5586 from julek-wolfssl/dtls-misc-security

Add missing minor security checks

src/dtls13.c

@@ -1846,6 +1846,20 @@ struct Dtls13Epoch* Dtls13GetEpoch(WOLFSSL* ssl, w64wrapper epochNumber)
     return NULL;
 }
 
+void Dtls13SetOlderEpochSide(WOLFSSL* ssl, w64wrapper epochNumber,
+                                    int side)
+{
+    Dtls13Epoch* e;
+    int i;
+
+    for (i = 0; i < DTLS13_EPOCH_SIZE; ++i) {
+        e = &ssl->dtls13Epochs[i];
+        if (e->isValid && w64LT(e->epochNumber, epochNumber)) {
+            e->side = (byte)side;
+        }
+    }
+}
+
 static void Dtls13EpochCopyKeys(WOLFSSL* ssl, Dtls13Epoch* e, Keys* k, int side)
 {
     byte clientWrite, serverWrite;
@@ -2011,6 +2025,14 @@ int Dtls13NewEpoch(WOLFSSL* ssl, w64wrapper epochNumber, int side)
         e->side = ENCRYPT_AND_DECRYPT_SIDE;
     }
 
+    /* Once handshake is done. Mark epochs older than the last one as encrypt
+     * only so that they can't be used for decryption. */
+    if (ssl->options.handShakeDone && (e->side == ENCRYPT_AND_DECRYPT_SIDE ||
+            e->side == DECRYPT_SIDE_ONLY)) {
+        w64Decrement(&epochNumber);
+        Dtls13SetOlderEpochSide(ssl, epochNumber, ENCRYPT_SIDE_ONLY);
+    }
+
     return 0;
 }
 
@@ -2373,6 +2395,13 @@ int Dtls13DoScheduledWork(WOLFSSL* ssl)
 
     ssl->dtls13SendingAckOrRtx = 0;
 
+    if (ssl->dtls13DoKeyUpdate) {
+        ssl->dtls13DoKeyUpdate = 0;
+        ret = Tls13UpdateKeys(ssl);
+        if (ret != 0)
+            return ret;
+    }
+
     return 0;
 }
 
@@ -2610,4 +2639,73 @@ int wolfSSL_dtls13_has_pending_msg(WOLFSSL* ssl)
     return ssl->dtls13Rtx.rtxRecords != NULL;
 }
 
+#ifndef WOLFSSL_TLS13_IGNORE_AEAD_LIMITS
+/* Limits specified by
+ * https://www.rfc-editor.org/rfc/rfc9147.html#name-aead-limits
+ * We specify the limit by which we need to do a key update as the halfway point
+ * to the hard decryption fail limit. */
+int Dtls13CheckAEADFailLimit(WOLFSSL* ssl)
+{
+    w64wrapper keyUpdateLimit;
+    w64wrapper hardLimit;
+    switch (ssl->specs.bulk_cipher_algorithm) {
+#if defined(BUILD_AESGCM) || (defined(HAVE_CHACHA) && defined(HAVE_POLY1305))
+        case wolfssl_aes_gcm:
+        case wolfssl_chacha:
+            hardLimit = DTLS_AEAD_AES_GCM_CHACHA_FAIL_LIMIT;
+            keyUpdateLimit = DTLS_AEAD_AES_GCM_CHACHA_FAIL_KU_LIMIT;
+            break;
+#endif
+#ifdef HAVE_AESCCM
+        case wolfssl_aes_ccm:
+            if (ssl->specs.aead_mac_size == AES_CCM_8_AUTH_SZ) {
+                /* Limit is 2^7. The RFC recommends that
+                 * "TLS_AES_128_CCM_8_SHA256 is not suitable for general use".
+                 * We still should enforce the limit. */
+                hardLimit = DTLS_AEAD_AES_CCM_8_FAIL_LIMIT;
+                keyUpdateLimit = DTLS_AEAD_AES_CCM_8_FAIL_KU_LIMIT;
+            }
+            else {
+                /* Limit is 2^23.5.
+                 * Without the fraction is 11863283 (0x00B504F3)
+                 * Half of this value is    5931641 (0x005A8279) */
+                hardLimit = DTLS_AEAD_AES_CCM_FAIL_LIMIT;
+                keyUpdateLimit = DTLS_AEAD_AES_CCM_FAIL_KU_LIMIT;
+            }
+            break;
+#endif
+        case wolfssl_cipher_null:
+            /* No encryption being done. The MAC check must have failed. */
+            return 0;
+        default:
+            WOLFSSL_MSG("Unrecognized ciphersuite for AEAD limit check");
+            WOLFSSL_ERROR_VERBOSE(DECRYPT_ERROR);
+            return DECRYPT_ERROR;
+    }
+    if (ssl->dtls13DecryptEpoch == NULL) {
+        WOLFSSL_MSG("Dtls13CheckAEADFailLimit: ssl->dtls13DecryptEpoch should "
+                    "not be NULL");
+        WOLFSSL_ERROR_VERBOSE(BAD_STATE_E);
+        return BAD_STATE_E;
+    }
+    w64Increment(&ssl->dtls13DecryptEpoch->dropCount);
+    if (w64GT(ssl->dtls13DecryptEpoch->dropCount, hardLimit)) {
+        /* We have reached the hard limit for failed decryptions. */
+        WOLFSSL_MSG("Connection exceeded hard AEAD limit");
+        WOLFSSL_ERROR_VERBOSE(DECRYPT_ERROR);
+        return DECRYPT_ERROR;
+    }
+    else if (w64GT(ssl->dtls13DecryptEpoch->dropCount, keyUpdateLimit)) {
+        WOLFSSL_MSG("Connection exceeded key update limit. Issuing key update");
+        /* If not waiting for a response then request a key update. */
+        if (!ssl->keys.updateResponseReq) {
+            ssl->dtls13DoKeyUpdate = 1;
+            ssl->dtls13InvalidateBefore = ssl->dtls13PeerEpoch;
+            w64Increment(&ssl->dtls13InvalidateBefore);
+        }
+    }
+    return 0;
+}
+#endif
+
 #endif /* WOLFSSL_DTLS13 */

src/internal.c

@@ -80,6 +80,12 @@
  *     Verifies the ECC signature after signing in case of faults in the
  *     calculation of the signature. Useful when signature fault injection is a
  *     possible attack.
+ * WOLFSSL_TLS13_IGNORE_AEAD_LIMITS
+ *     Ignore the AEAD limits for messages specified in the RFC. After
+ *     reaching the limit, we initiate a key update. We enforce the AEAD limits
+ *     by default.
+ *     https://www.rfc-editor.org/rfc/rfc8446#section-5.5
+ *     https://www.rfc-editor.org/rfc/rfc9147.html#name-aead-limits
  */
 
 
@@ -18247,6 +18253,23 @@ int DoApplicationData(WOLFSSL* ssl, byte* input, word32* inOutIdx, int sniff)
         return OUT_OF_ORDER_E;
     }
 
+
+#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_TLS13_IGNORE_AEAD_LIMITS)
+    /* Check if we want to invalidate old epochs. If
+     * ssl->dtls13InvalidateBefore is set then we want to mark all old
+     * epochs as encrypt only. This is done when we detect too many failed
+     * decryptions. We do this here to confirm that the peer has updated its
+     * keys and we can stop using the old keys. */
+    if (ssl->options.dtls && IsAtLeastTLSv1_3(ssl->version)) {
+        if (!w64IsZero(ssl->dtls13InvalidateBefore) &&
+                w64Equal(ssl->keys.curEpoch64, ssl->dtls13InvalidateBefore)) {
+            Dtls13SetOlderEpochSide(ssl, ssl->dtls13InvalidateBefore,
+                                    ENCRYPT_SIDE_ONLY);
+            w64Zero(&ssl->dtls13InvalidateBefore);
+        }
+    }
+#endif
+
 #ifndef WOLFSSL_AEAD_ONLY
     if (ssl->specs.cipher_type == block) {
         if (ssl->options.tls1_1)
@@ -18831,6 +18854,26 @@ static WC_INLINE int VerifyMac(WOLFSSL* ssl, const byte* input, word32 msgSz,
     return 0;
 }
 
+#ifdef WOLFSSL_DTLS
+static int HandleDTLSDecryptFailed(WOLFSSL* ssl)
+{
+    int ret = 0;
+#ifdef WOLFSSL_DTLS_DROP_STATS
+    ssl->macDropCount++;
+#endif
+
+#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_TLS13_IGNORE_AEAD_LIMITS)
+    /* Handle AEAD limits specified by the RFC for failed decryption */
+    if (IsAtLeastTLSv1_3(ssl->version))
+        ret = Dtls13CheckAEADFailLimit(ssl);
+#endif
+
+    (void)ssl;
+    WOLFSSL_MSG("DTLS: Ignoring failed decryption");
+    return ret;
+}
+#endif
+
 int ProcessReply(WOLFSSL* ssl)
 {
     return ProcessReplyEx(ssl, 0);
@@ -19137,17 +19180,14 @@ int ProcessReplyEx(WOLFSSL* ssl, int allowSocketErr)
             #endif
                 if (ret < 0) {
                     WOLFSSL_MSG("VerifyMacEnc failed");
-                    WOLFSSL_ERROR(ret);
                 #ifdef WOLFSSL_DTLS
                     /* If in DTLS mode, if the decrypt fails for any
                      * reason, pretend the datagram never happened. */
                     if (ssl->options.dtls) {
                         ssl->options.processReply = doProcessInit;
                         ssl->buffers.inputBuffer.idx =
-                                        ssl->buffers.inputBuffer.length;
+                                ssl->buffers.inputBuffer.length;
-                        #ifdef WOLFSSL_DTLS_DROP_STATS
+                        return HandleDTLSDecryptFailed(ssl);
-                            ssl->macDropCount++;
-                        #endif /* WOLFSSL_DTLS_DROP_STATS */
                     }
                 #endif /* WOLFSSL_DTLS */
                 #ifdef WOLFSSL_EXTRA_ALERTS
@@ -19304,14 +19344,10 @@ int ProcessReplyEx(WOLFSSL* ssl, int allowSocketErr)
                     /* If in DTLS mode, if the decrypt fails for any
                      * reason, pretend the datagram never happened. */
                     if (ssl->options.dtls) {
-                        WOLFSSL_MSG("DTLS: Ignoring failed decryption");
                         ssl->options.processReply = doProcessInit;
                         ssl->buffers.inputBuffer.idx =
-                                        ssl->buffers.inputBuffer.length;
+                                ssl->buffers.inputBuffer.length;
-                    #ifdef WOLFSSL_DTLS_DROP_STATS
+                        return HandleDTLSDecryptFailed(ssl);
-                        ssl->macDropCount++;
-                    #endif /* WOLFSSL_DTLS_DROP_STATS */
-                        return 0;
                     }
                 #endif /* WOLFSSL_DTLS */
                 #ifdef WOLFSSL_EARLY_DATA
@@ -19374,24 +19410,21 @@ int ProcessReplyEx(WOLFSSL* ssl, int allowSocketErr)
                         return ret;
                 #endif
                     if (ret < 0) {
-                        WOLFSSL_MSG("VerifyMac failed");
-                        WOLFSSL_ERROR(ret);
                     #ifdef WOLFSSL_DTLS
                         /* If in DTLS mode, if the decrypt fails for any
                          * reason, pretend the datagram never happened. */
                         if (ssl->options.dtls) {
                             ssl->options.processReply = doProcessInit;
                             ssl->buffers.inputBuffer.idx =
-                                            ssl->buffers.inputBuffer.length;
+                                    ssl->buffers.inputBuffer.length;
-                            #ifdef WOLFSSL_DTLS_DROP_STATS
+                            return HandleDTLSDecryptFailed(ssl);
-                                ssl->macDropCount++;
-                            #endif /* WOLFSSL_DTLS_DROP_STATS */
                         }
                     #endif /* WOLFSSL_DTLS */
                     #ifdef WOLFSSL_EXTRA_ALERTS
                         if (!ssl->options.dtls)
                             SendAlert(ssl, alert_fatal, bad_record_mac);
                     #endif
+                        WOLFSSL_MSG("VerifyMac failed");
                         WOLFSSL_ERROR_VERBOSE(DECRYPT_ERROR);
                         return DECRYPT_ERROR;
                     }
@@ -22021,6 +22054,66 @@ static int ModifyForMTU(WOLFSSL* ssl, int buffSz, int outputSz, int mtuSz)
 }
 #endif /* WOLFSSL_DTLS */
 
+#if defined(WOLFSSL_TLS13) && !defined(WOLFSSL_TLS13_IGNORE_AEAD_LIMITS)
+/*
+ * Enforce limits specified in
+ * https://www.rfc-editor.org/rfc/rfc8446#section-5.5
+ */
+static int CheckTLS13AEADSendLimit(WOLFSSL* ssl)
+{
+    w64wrapper seq;
+    w64wrapper limit;
+
+    switch (ssl->specs.bulk_cipher_algorithm) {
+#ifdef BUILD_AESGCM
+        case wolfssl_aes_gcm:
+            /* Limit is 2^24.5 */
+            limit = AEAD_AES_LIMIT;
+            break;
+#endif
+#if defined(HAVE_CHACHA) && defined(HAVE_POLY1305)
+        case wolfssl_chacha:
+            /* For ChaCha20/Poly1305, the record sequence number would wrap
+             * before the safety limit is reached. */
+            return 0;
+#endif
+#ifdef HAVE_AESCCM
+        case wolfssl_aes_ccm:
+            /* Use the limits calculated in the DTLS 1.3 spec
+             * https://www.rfc-editor.org/rfc/rfc9147.html#name-analysis-of-limits-on-ccm-u */
+#ifdef WOLFSSL_DTLS13
+            if (ssl->options.dtls)
+                limit = DTLS_AEAD_AES_CCM_LIMIT; /* Limit is 2^23 */
+            else
+#endif
+                limit = AEAD_AES_LIMIT; /* Limit is 2^24.5 */
+            break;
+#endif
+        case wolfssl_cipher_null:
+            /* No encryption being done */
+            return 0;
+        default:
+            WOLFSSL_MSG("Unrecognized ciphersuite for AEAD limit check");
+            return BAD_STATE_E;
+
+    }
+#ifdef WOLFSSL_DTLS13
+    if (ssl->options.dtls) {
+        seq = ssl->dtls13EncryptEpoch->nextSeqNumber;
+    }
+    else
+#endif
+    {
+        seq = w64From32(ssl->keys.sequence_number_hi,
+                ssl->keys.sequence_number_lo);
+    }
+
+    if (w64GTE(seq, limit))
+        return Tls13UpdateKeys(ssl); /* Need to generate new keys */
+
+    return 0;
+}
+#endif /* WOLFSSL_TLS13 && !WOLFSSL_TLS13_IGNORE_AEAD_LIMITS */
 
 int SendData(WOLFSSL* ssl, const void* data, int sz)
 {
@@ -22123,6 +22216,16 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
         byte  comp[MAX_RECORD_SIZE + MAX_COMP_EXTRA];
 #endif
 
+#if defined(WOLFSSL_TLS13) && !defined(WOLFSSL_TLS13_IGNORE_AEAD_LIMITS)
+        if (IsAtLeastTLSv1_3(ssl->version)) {
+            ret = CheckTLS13AEADSendLimit(ssl);
+            if (ret != 0) {
+                ssl->error = ret;
+                return WOLFSSL_FATAL_ERROR;
+            }
+        }
+#endif
+
 #ifdef WOLFSSL_DTLS13
         if (ssl->options.dtls && ssl->options.tls1_3) {
             byte isEarlyData = 0;

src/ssl.c

@@ -3172,6 +3172,11 @@ static int _Rehandshake(WOLFSSL* ssl)
     if (ssl == NULL)
         return BAD_FUNC_ARG;
 
+    if (IsAtLeastTLSv1_3(ssl->version)) {
+        WOLFSSL_MSG("Secure Renegotiation not supported in TLS 1.3");
+        return SECURE_RENEGOTIATION_E;
+    }
+
     if (ssl->secure_renegotiation == NULL) {
         WOLFSSL_MSG("Secure Renegotiation not forced on by user");
         return SECURE_RENEGOTIATION_E;
@@ -3182,6 +3187,13 @@ static int _Rehandshake(WOLFSSL* ssl)
         return SECURE_RENEGOTIATION_E;
     }
 
+#ifdef WOLFSSL_DTLS
+    if (ssl->options.dtls && ssl->keys.dtls_epoch == 0xFFFF) {
+        WOLFSSL_MSG("Secure Renegotiation not allowed. Epoch would wrap");
+        return SECURE_RENEGOTIATION_E;
+    }
+#endif
+
     /* If the client started the renegotiation, the server will already
      * have processed the client's hello. */
     if (ssl->options.side != WOLFSSL_SERVER_END ||

src/tls13.c

@@ -2097,7 +2097,7 @@ static WC_INLINE void WriteSEQTls13(WOLFSSL* ssl, int verifyOrder, byte* out)
         Dtls13GetSeq(ssl, verifyOrder, seq, 1);
 #endif /* WOLFSSL_DTLS13 */
     }
-    else if (verifyOrder) {
+    else if (verifyOrder == PEER_ORDER) {
         seq[0] = ssl->keys.peer_sequence_number_hi;
         seq[1] = ssl->keys.peer_sequence_number_lo++;
         /* handle rollover */
@@ -11130,6 +11130,26 @@ int wolfSSL_no_dhe_psk(WOLFSSL* ssl)
     return 0;
 }
 
+
+int Tls13UpdateKeys(WOLFSSL* ssl)
+{
+    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
+        return BAD_FUNC_ARG;
+
+#ifdef WOLFSSL_DTLS13
+    /* we are already waiting for the ack of a sent key update message. We can't
+       send another one before receiving its ack. Either wolfSSL_update_keys()
+       was invoked multiple times over a short period of time or we replied to a
+       KeyUpdate with update request. We'll just ignore sending this
+       KeyUpdate. */
+    /* TODO: add WOLFSSL_ERROR_ALREADY_IN_PROGRESS type of error here */
+    if (ssl->options.dtls && ssl->dtls13WaitKeyUpdateAck)
+        return 0;
+#endif /* WOLFSSL_DTLS13 */
+
+    return SendTls13KeyUpdate(ssl);
+}
+
 /* Update the keys for encryption and decryption.
  * If using non-blocking I/O and WOLFSSL_ERROR_WANT_WRITE is returned then
  * calling wolfSSL_write() will have the message sent when ready.
@@ -11142,22 +11162,7 @@ int wolfSSL_no_dhe_psk(WOLFSSL* ssl)
 int wolfSSL_update_keys(WOLFSSL* ssl)
 {
     int ret;
-
+    ret = Tls13UpdateKeys(ssl);
-    if (ssl == NULL || !IsAtLeastTLSv1_3(ssl->version))
-        return BAD_FUNC_ARG;
-
-#ifdef WOLFSSL_DTLS13
-    /* we are already waiting for the ack of a sent key update message. We can't
-       send another one before receiving its ack. Either wolfSSL_update_keys()
-       was invoked multiple times over a short period of time or we replied to a
-       KeyUpdate with update request. We'll just ignore sending this
-       KeyUpdate. */
-    /* TODO: add WOLFSSL_ERROR_ALREADY_IN_PROGRESS type of error here */
-    if (ssl->options.dtls && ssl->dtls13WaitKeyUpdateAck)
-            return WOLFSSL_SUCCESS;
-#endif /* WOLFSSL_DTLS13 */
-
-    ret = SendTls13KeyUpdate(ssl);
     if (ret == WANT_WRITE)
         ret = WOLFSSL_ERROR_WANT_WRITE;
     else if (ret == 0)

tests/api.c

@@ -5786,6 +5786,49 @@ done:
     return 0;
 }
 
+void test_wolfSSL_client_server_nofail(callback_functions* client_cb,
+                                       callback_functions* server_cb)
+{
+    func_args client_args;
+    func_args server_args;
+    tcp_ready ready;
+    THREAD_TYPE serverThread;
+
+    XMEMSET(&client_args, 0, sizeof(func_args));
+    XMEMSET(&server_args, 0, sizeof(func_args));
+
+#ifdef WOLFSSL_TIRTOS
+    fdOpenSession(Task_self());
+#endif
+
+    StartTCP();
+    InitTcpReady(&ready);
+
+#if defined(USE_WINDOWS_API)
+    /* use RNG to get random port if using windows */
+    ready.port = GetRandomPort();
+#endif
+
+    server_args.signal = &ready;
+    server_args.callbacks = server_cb;
+    client_args.signal = &ready;
+    client_args.callbacks = client_cb;
+
+    start_thread(test_server_nofail, &server_args, &serverThread);
+    wait_tcp_ready(&server_args);
+    test_client_nofail(&client_args, NULL);
+    join_thread(serverThread);
+
+    client_cb->return_code = client_args.return_code;
+    server_cb->return_code = server_args.return_code;
+
+    FreeTcpReady(&ready);
+
+#ifdef WOLFSSL_TIRTOS
+    fdOpenSession(Task_self());
+#endif
+}
+
 #if defined(OPENSSL_EXTRA) && !defined(NO_SESSION_CACHE) && \
    !defined(WOLFSSL_TLS13) && !defined(NO_WOLFSSL_CLIENT)
 static void test_client_reuse_WOLFSSLobj(void* args, void *cb, void* server_args)
@@ -55575,12 +55618,8 @@ static void test_wolfSSL_dtls_plaintext_client(WOLFSSL* ssl)
 
 static int test_wolfSSL_dtls_plaintext(void)
 {
-    tcp_ready ready;
-    func_args client_args;
-    func_args server_args;
     callback_functions func_cb_client;
     callback_functions func_cb_server;
-    THREAD_TYPE serverThread;
     size_t i;
     struct test_params {
         method_provider client_meth;
@@ -55596,47 +55635,21 @@ static int test_wolfSSL_dtls_plaintext(void)
     printf(testingFmt, "test_wolfSSL_dtls_plaintext");
 
     for (i = 0; i < sizeof(params)/sizeof(*params); i++) {
-        XMEMSET(&client_args, 0, sizeof(func_args));
-        XMEMSET(&server_args, 0, sizeof(func_args));
         XMEMSET(&func_cb_client, 0, sizeof(callback_functions));
         XMEMSET(&func_cb_server, 0, sizeof(callback_functions));
 
-    #ifdef WOLFSSL_TIRTOS
-        fdOpenSession(Task_self());
-    #endif
-
-        StartTCP();
-        InitTcpReady(&ready);
-
-#if defined(USE_WINDOWS_API)
-        /* use RNG to get random port if using windows */
-        ready.port = GetRandomPort();
-#endif
-
-        server_args.signal = &ready;
-        server_args.callbacks = &func_cb_server;
-        client_args.signal = &ready;
-        client_args.callbacks = &func_cb_client;
-
         func_cb_client.doUdp = func_cb_server.doUdp = 1;
         func_cb_server.method = params[i].server_meth;
         func_cb_client.method = params[i].client_meth;
         func_cb_client.on_result = params[i].on_result_client;
         func_cb_server.on_result = params[i].on_result_server;
 
-        start_thread(test_server_nofail, &server_args, &serverThread);
+        test_wolfSSL_client_server_nofail(&func_cb_client, &func_cb_server);
-        wait_tcp_ready(&server_args);
-        test_client_nofail(&client_args, NULL);
-        join_thread(serverThread);
 
-        AssertTrue(client_args.return_code);
+        if (!func_cb_client.return_code)
-        AssertTrue(server_args.return_code);
+            return -1;
-
+        if (!func_cb_server.return_code)
-        FreeTcpReady(&ready);
+            return -2;
-
-#ifdef WOLFSSL_TIRTOS
-        fdOpenSession(Task_self());
-#endif
     }
 
     printf(resultFmt, passed);
@@ -55761,12 +55774,8 @@ static void test_wolfSSL_dtls13_fragments_spammer(WOLFSSL* ssl)
 
 static int test_wolfSSL_dtls_fragments(void)
 {
-    tcp_ready ready;
-    func_args client_args;
-    func_args server_args;
     callback_functions func_cb_client;
     callback_functions func_cb_server;
-    THREAD_TYPE serverThread;
     size_t i;
     struct test_params {
         method_provider client_meth;
@@ -55784,52 +55793,26 @@ static int test_wolfSSL_dtls_fragments(void)
     printf(testingFmt, "test_wolfSSL_dtls_fragments");
 
     for (i = 0; i < sizeof(params)/sizeof(*params); i++) {
-        XMEMSET(&client_args, 0, sizeof(func_args));
-        XMEMSET(&server_args, 0, sizeof(func_args));
         XMEMSET(&func_cb_client, 0, sizeof(callback_functions));
         XMEMSET(&func_cb_server, 0, sizeof(callback_functions));
 
-    #ifdef WOLFSSL_TIRTOS
-        fdOpenSession(Task_self());
-    #endif
-
-        StartTCP();
-        InitTcpReady(&ready);
-
-#if defined(USE_WINDOWS_API)
-        /* use RNG to get random port if using windows */
-        ready.port = GetRandomPort();
-#endif
-
-        server_args.signal = &ready;
-        server_args.callbacks = &func_cb_server;
-        client_args.signal = &ready;
-        client_args.callbacks = &func_cb_client;
 
         func_cb_client.doUdp = func_cb_server.doUdp = 1;
         func_cb_server.method = params[i].server_meth;
         func_cb_client.method = params[i].client_meth;
         func_cb_client.ssl_ready = params[i].spammer;
 
-        start_thread(test_server_nofail, &server_args, &serverThread);
+        test_wolfSSL_client_server_nofail(&func_cb_client, &func_cb_server);
-        wait_tcp_ready(&server_args);
+
-        test_client_nofail(&client_args, NULL);
+        AssertFalse(func_cb_client.return_code);
-        join_thread(serverThread);
+        AssertFalse(func_cb_server.return_code);
 
-        AssertFalse(client_args.return_code);
-        AssertFalse(server_args.return_code);
         /* The socket should be closed by the server resulting in a
          * socket error */
         AssertIntEQ(func_cb_client.last_err, SOCKET_ERROR_E);
         /* Check the server returned an error indicating the msg buffer
          * was full */
         AssertIntEQ(func_cb_server.last_err, DTLS_TOO_MANY_FRAGMENTS_E);
-
-        FreeTcpReady(&ready);
-
-#ifdef WOLFSSL_TIRTOS
-        fdOpenSession(Task_self());
-#endif
     }
 
     printf(resultFmt, passed);
@@ -55842,6 +55825,206 @@ static int test_wolfSSL_dtls_fragments(void) {
 }
 #endif
 
+#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_TLS13_IGNORE_AEAD_LIMITS)
+static byte test_AEAD_fail_decryption = 0;
+static byte test_AEAD_seq_num = 0;
+static byte test_AEAD_done = 0;
+
+static int test_AEAD_cbiorecv(WOLFSSL *ssl, char *buf, int sz, void *ctx)
+{
+    int ret = recv(wolfSSL_get_fd(ssl), buf, sz, 0);
+    if (ret > 0) {
+        if (test_AEAD_fail_decryption) {
+            /* Modify the packet to trigger a decryption failure */
+            buf[ret/2] ^= 0xFF;
+            if (test_AEAD_fail_decryption == 1)
+                test_AEAD_fail_decryption = 0;
+        }
+    }
+    (void)ctx;
+    return ret;
+}
+
+static void test_AEAD_get_limits(WOLFSSL* ssl, w64wrapper* hardLimit,
+        w64wrapper* keyUpdateLimit, w64wrapper* sendLimit)
+{
+    if (sendLimit)
+        w64Zero(sendLimit);
+    switch (ssl->specs.bulk_cipher_algorithm) {
+        case wolfssl_aes_gcm:
+            if (sendLimit)
+                *sendLimit = AEAD_AES_LIMIT;
+            FALL_THROUGH;
+        case wolfssl_chacha:
+            if (hardLimit)
+                *hardLimit = DTLS_AEAD_AES_GCM_CHACHA_FAIL_LIMIT;
+            if (keyUpdateLimit)
+                *keyUpdateLimit = DTLS_AEAD_AES_GCM_CHACHA_FAIL_KU_LIMIT;
+            break;
+        case wolfssl_aes_ccm:
+            if (sendLimit)
+                *sendLimit = DTLS_AEAD_AES_CCM_LIMIT;
+            if (ssl->specs.aead_mac_size == AES_CCM_8_AUTH_SZ) {
+                if (hardLimit)
+                    *hardLimit = DTLS_AEAD_AES_CCM_8_FAIL_LIMIT;
+                if (keyUpdateLimit)
+                    *keyUpdateLimit = DTLS_AEAD_AES_CCM_8_FAIL_KU_LIMIT;
+            }
+            else {
+                if (hardLimit)
+                    *hardLimit = DTLS_AEAD_AES_CCM_FAIL_LIMIT;
+                if (keyUpdateLimit)
+                    *keyUpdateLimit = DTLS_AEAD_AES_CCM_FAIL_KU_LIMIT;
+            }
+            break;
+        default:
+            fprintf(stderr, "Unrecognized bulk cipher");
+            AssertFalse(1);
+            break;
+    }
+}
+
+static void test_AEAD_limit_client(WOLFSSL* ssl)
+{
+    int ret;
+    int i;
+    int didReKey = 0;
+    char msgBuf[20];
+    w64wrapper hardLimit;
+    w64wrapper keyUpdateLimit;
+    w64wrapper counter;
+    w64wrapper sendLimit;
+
+    test_AEAD_get_limits(ssl, &hardLimit, &keyUpdateLimit, &sendLimit);
+
+    w64Zero(&counter);
+    AssertTrue(w64Equal(Dtls13GetEpoch(ssl, ssl->dtls13Epoch)->dropCount, counter));
+
+    wolfSSL_SSLSetIORecv(ssl, test_AEAD_cbiorecv);
+
+    for (i = 0; i < 10; i++) {
+        /* Test some failed decryptions */
+        test_AEAD_fail_decryption = 1;
+        w64Increment(&counter);
+        ret = wolfSSL_read(ssl, msgBuf, sizeof(msgBuf));
+        /* Should succeed since decryption failures are dropped */
+        AssertIntGT(ret, 0);
+        AssertTrue(w64Equal(Dtls13GetEpoch(ssl, ssl->dtls13PeerEpoch)->dropCount, counter));
+    }
+
+    test_AEAD_fail_decryption = 1;
+    Dtls13GetEpoch(ssl, ssl->dtls13PeerEpoch)->dropCount = keyUpdateLimit;
+    w64Increment(&Dtls13GetEpoch(ssl, ssl->dtls13PeerEpoch)->dropCount);
+    /* 100 read calls should be enough to complete the key update */
+    w64Zero(&counter);
+    for (i = 0; i < 100; i++) {
+        /* Key update should be sent and negotiated */
+        ret = wolfSSL_read(ssl, msgBuf, sizeof(msgBuf));
+        AssertIntGT(ret, 0);
+        /* Epoch after one key update is 4 */
+        if (w64Equal(ssl->dtls13PeerEpoch, w64From32(0, 4)) &&
+                w64Equal(Dtls13GetEpoch(ssl, ssl->dtls13PeerEpoch)->dropCount, counter)) {
+            didReKey = 1;
+            break;
+        }
+    }
+    AssertTrue(didReKey);
+
+    if (!w64IsZero(sendLimit)) {
+        /* Test the sending limit for AEAD ciphers */
+        Dtls13GetEpoch(ssl, ssl->dtls13Epoch)->nextSeqNumber = sendLimit;
+        test_AEAD_seq_num = 1;
+        ret = wolfSSL_write(ssl, msgBuf, sizeof(msgBuf));
+        AssertIntGT(ret, 0);
+        didReKey = 0;
+        w64Zero(&counter);
+        /* 100 read calls should be enough to complete the key update */
+        for (i = 0; i < 100; i++) {
+            /* Key update should be sent and negotiated */
+            ret = wolfSSL_read(ssl, msgBuf, sizeof(msgBuf));
+            AssertIntGT(ret, 0);
+            /* Epoch after another key update is 5 */
+            if (w64Equal(ssl->dtls13Epoch, w64From32(0, 5)) &&
+                    w64Equal(Dtls13GetEpoch(ssl, ssl->dtls13Epoch)->dropCount, counter)) {
+                didReKey = 1;
+                break;
+            }
+        }
+        AssertTrue(didReKey);
+    }
+
+    test_AEAD_fail_decryption = 2;
+    Dtls13GetEpoch(ssl, ssl->dtls13PeerEpoch)->dropCount = hardLimit;
+    w64Decrement(&Dtls13GetEpoch(ssl, ssl->dtls13PeerEpoch)->dropCount);
+    /* Connection should fail with a DECRYPT_ERROR */
+    ret = wolfSSL_read(ssl, msgBuf, sizeof(msgBuf));
+    AssertIntEQ(ret, WOLFSSL_FATAL_ERROR);
+    AssertIntEQ(wolfSSL_get_error(ssl, ret), DECRYPT_ERROR);
+
+    test_AEAD_done = 1;
+}
+
+int counter = 0;
+static void test_AEAD_limit_server(WOLFSSL* ssl)
+{
+    char msgBuf[] = "Sending data";
+    int ret = WOLFSSL_SUCCESS;
+    w64wrapper sendLimit;
+    SOCKET_T fd = wolfSSL_get_fd(ssl);
+    struct timespec delay;
+    XMEMSET(&delay, 0, sizeof(delay));
+    delay.tv_nsec = 100000000; /* wait 0.1 seconds */
+    tcp_set_nonblocking(&fd); /* So that read doesn't block */
+    test_AEAD_get_limits(ssl, NULL, NULL, &sendLimit);
+    while (!test_AEAD_done && ret > 0) {
+        counter++;
+        if (test_AEAD_seq_num) {
+            /* We need to update the seq number so that we can understand the
+             * peer. Otherwise we will incorrectly interpret the seq number. */
+            Dtls13Epoch* e = Dtls13GetEpoch(ssl, ssl->dtls13PeerEpoch);
+            AssertNotNull(e);
+            e->nextPeerSeqNumber = sendLimit;
+            test_AEAD_seq_num = 0;
+        }
+        (void)wolfSSL_read(ssl, msgBuf, sizeof(msgBuf));
+        ret = wolfSSL_write(ssl, msgBuf, sizeof(msgBuf));
+        nanosleep(&delay, NULL);
+    }
+}
+
+static int test_wolfSSL_dtls_AEAD_limit(void)
+{
+    callback_functions func_cb_client;
+    callback_functions func_cb_server;
+    XMEMSET(&func_cb_client, 0, sizeof(callback_functions));
+    XMEMSET(&func_cb_server, 0, sizeof(callback_functions));
+
+    printf(testingFmt, "test_wolfSSL_dtls_AEAD_limit");
+
+    func_cb_client.doUdp = func_cb_server.doUdp = 1;
+    func_cb_server.method = wolfDTLSv1_3_server_method;
+    func_cb_client.method = wolfDTLSv1_3_client_method;
+    func_cb_server.on_result = test_AEAD_limit_server;
+    func_cb_client.on_result = test_AEAD_limit_client;
+
+    test_wolfSSL_client_server_nofail(&func_cb_client, &func_cb_server);
+
+    if (!func_cb_client.return_code)
+        return -1;
+    if (!func_cb_server.return_code)
+        return -2;
+
+    printf(resultFmt, passed);
+
+    return 0;
+}
+#else
+static int test_wolfSSL_dtls_AEAD_limit(void)
+{
+    return 0;
+}
+#endif
+
 #if !defined(NO_RSA) && !defined(NO_SHA) && !defined(NO_FILESYSTEM) && \
     !defined(NO_CERTS) && (!defined(NO_WOLFSSL_CLIENT) || \
     !defined(WOLFSSL_NO_CLIENT_AUTH))
@@ -58553,6 +58736,7 @@ TEST_CASE testCases[] = {
     TEST_DECL(test_wolfSSL_either_side),
     TEST_DECL(test_wolfSSL_DTLS_either_side),
     TEST_DECL(test_wolfSSL_dtls_fragments),
+    TEST_DECL(test_wolfSSL_dtls_AEAD_limit),
     TEST_DECL(test_generate_cookie),
     TEST_DECL(test_wolfSSL_X509_STORE_set_flags),
     TEST_DECL(test_wolfSSL_X509_LOOKUP_load_file),

wolfssl/internal.h

@@ -1274,6 +1274,30 @@ enum {
 #define TLS13_MAX_TICKET_AGE    (7*24*60*60)
 #endif
 
+
+/* Limit is 2^24.5
+ * https://www.rfc-editor.org/rfc/rfc8446#section-5.5
+ * Without the fraction is 23726566 (0x016A09E6) */
+#define AEAD_AES_LIMIT                           w64From32(0x016A, 0x09E6)
+/* Limit is 2^23
+ * https://www.rfc-editor.org/rfc/rfc9147.html#name-integrity-limits */
+#define DTLS_AEAD_AES_CCM_LIMIT                  w64From32(0, 1 << 22)
+
+/* Limit is 2^36
+ * https://www.rfc-editor.org/rfc/rfc9147.html#name-aead-limits */
+#define DTLS_AEAD_AES_GCM_CHACHA_FAIL_LIMIT      w64From32(1 << 3, 0)
+#define DTLS_AEAD_AES_GCM_CHACHA_FAIL_KU_LIMIT   w64From32(1 << 2, 0)
+/* Limit is 2^7
+ * https://www.rfc-editor.org/rfc/rfc9147.html#name-limits-for-aead_aes_128_ccm */
+#define DTLS_AEAD_AES_CCM_8_FAIL_LIMIT           w64From32(0, 1 << 6)
+#define DTLS_AEAD_AES_CCM_8_FAIL_KU_LIMIT        w64From32(0, 1 << 5)
+/* Limit is 2^23.5.
+ * https://www.rfc-editor.org/rfc/rfc9147.html#name-integrity-limits
+ * Without the fraction is 11863283 (0x00B504F3)
+ * Half of this value is    5931641 (0x005A8279) */
+#define DTLS_AEAD_AES_CCM_FAIL_LIMIT             w64From32(0x00B5, 0x04F3)
+#define DTLS_AEAD_AES_CCM_FAIL_KU_LIMIT          w64From32(0x005A, 0x8279)
+
 enum Misc {
     CIPHER_BYTE    = 0x00,         /* Default ciphers */
     ECC_BYTE       = 0xC0,         /* ECC first cipher suite byte */
@@ -4035,6 +4059,10 @@ typedef struct Options {
 #endif
 #endif
 #ifdef WOLFSSL_DTLS
+#ifdef HAVE_SECURE_RENEGOTIATION
+    word16            dtlsDoSCR:1;        /* Enough packets were dropped. We
+                                           * need to re-key. */
+#endif
     word16            dtlsUseNonblock:1;  /* are we using nonblocking socket */
     word16            dtlsHsRetain:1;     /* DTLS retaining HS data */
     word16            haveMcast:1;        /* using multicast ? */
@@ -4632,6 +4660,10 @@ typedef struct Dtls13Epoch {
     w64wrapper nextSeqNumber;
     w64wrapper nextPeerSeqNumber;
 
+#ifndef WOLFSSL_TLS13_IGNORE_AEAD_LIMITS
+    w64wrapper dropCount; /* Amount of records that failed decryption */
+#endif
+
     word32 window[WOLFSSL_DTLS_WINDOW_WORDS];
 
     /* key material for the epoch */
@@ -4687,10 +4719,10 @@ typedef struct Dtls13Rtx {
     Dtls13RtxRecord *rtxRecords;
     Dtls13RtxRecord **rtxRecordTailPtr;
     Dtls13RecordNumber *seenRecords;
+    word32 lastRtx;
     byte triggeredRtxs;
     byte sendAcks:1;
     byte retransmit:1;
-    word32 lastRtx;
 } Dtls13Rtx;
 
 #endif /* WOLFSSL_DTLS13 */
@@ -4910,6 +4942,7 @@ struct WOLFSSL {
     Dtls13Epoch *dtls13DecryptEpoch;
     w64wrapper dtls13Epoch;
     w64wrapper dtls13PeerEpoch;
+    w64wrapper dtls13InvalidateBefore;
     byte dtls13CurRL[DTLS_RECVD_RL_HEADER_MAX_SZ];
     word16 dtls13CurRlLength;
 
@@ -4919,6 +4952,7 @@ struct WOLFSSL {
     byte dtls13SendingAckOrRtx:1;
     byte dtls13FastTimeout:1;
     byte dtls13WaitKeyUpdateAck:1;
+    byte dtls13DoKeyUpdate:1;
     word32 dtls13MessageLength;
     word32 dtls13FragOffset;
     byte dtls13FragHandshakeType;
@@ -5666,6 +5700,7 @@ WOLFSSL_LOCAL int BuildMessage(WOLFSSL* ssl, byte* output, int outSz,
 /* Use WOLFSSL_API to use this function in tests/api.c */
 WOLFSSL_API int BuildTls13Message(WOLFSSL* ssl, byte* output, int outSz, const byte* input,
                int inSz, int type, int hashOutput, int sizeOnly, int asyncOkay);
+WOLFSSL_LOCAL int Tls13UpdateKeys(WOLFSSL* ssl);
 #endif
 
 WOLFSSL_LOCAL int AllocKey(WOLFSSL* ssl, int type, void** pKey);
@@ -5726,8 +5761,11 @@ WOLFSSL_API int wolfSSL_DtlsUpdateWindow(word16 cur_hi, word32 cur_lo,
 
 #ifdef WOLFSSL_DTLS13
 
-WOLFSSL_LOCAL struct Dtls13Epoch* Dtls13GetEpoch(WOLFSSL* ssl,
+/* Use WOLFSSL_API to use this function in tests/api.c */
+WOLFSSL_API struct Dtls13Epoch* Dtls13GetEpoch(WOLFSSL* ssl,
     w64wrapper epochNumber);
+WOLFSSL_LOCAL void Dtls13SetOlderEpochSide(WOLFSSL* ssl, w64wrapper epochNumber,
+    int side);
 WOLFSSL_LOCAL int Dtls13NewEpoch(WOLFSSL* ssl, w64wrapper epochNumber,
     int side);
 WOLFSSL_LOCAL int Dtls13SetEpochKeys(WOLFSSL* ssl, w64wrapper epochNumber,
@@ -5779,6 +5817,7 @@ WOLFSSL_LOCAL int Dtls13HashHandshake(WOLFSSL* ssl, const byte* output,
 WOLFSSL_LOCAL void Dtls13FreeFsmResources(WOLFSSL* ssl);
 WOLFSSL_LOCAL int Dtls13RtxTimeout(WOLFSSL* ssl);
 WOLFSSL_LOCAL int Dtls13ProcessBufferedMessages(WOLFSSL* ssl);
+WOLFSSL_LOCAL int Dtls13CheckAEADFailLimit(WOLFSSL* ssl);
 #endif /* WOLFSSL_DTLS13 */
 
 #ifdef WOLFSSL_STATIC_EPHEMERAL

wolfssl/test.h

@@ -657,6 +657,9 @@ typedef THREAD_RETURN WOLFSSL_THREAD THREAD_FUNC(void*);
 void start_thread(THREAD_FUNC fun, func_args* args, THREAD_TYPE* thread);
 void join_thread(THREAD_TYPE thread);
 
+void test_wolfSSL_client_server_nofail(callback_functions* client_cb,
+                                       callback_functions* server_cb);
+
 /* wolfSSL */
 #ifndef TEST_IPV6
     static const char* const wolfSSLIP   = "127.0.0.1";

wolfssl/wolfcrypt/misc.h

@@ -130,6 +130,24 @@ WOLFSSL_LOCAL void ctMaskCopy(byte mask, byte* dst, byte* src, word16 size);
 WOLFSSL_LOCAL word32 MakeWordFromHash(const byte* hashID);
 WOLFSSL_LOCAL word32 HashObject(const byte* o, word32 len, int* error);
 
+WOLFSSL_LOCAL void w64Increment(w64wrapper *n);
+WOLFSSL_LOCAL void w64Decrement(w64wrapper *n);
+WOLFSSL_LOCAL byte w64Equal(w64wrapper a, w64wrapper b);
+WOLFSSL_LOCAL word32 w64GetLow32(w64wrapper n);
+WOLFSSL_LOCAL word32 w64GetHigh32(w64wrapper n);
+WOLFSSL_LOCAL void w64SetLow32(w64wrapper *n, word32 low);
+WOLFSSL_LOCAL w64wrapper w64Add32(w64wrapper a, word32 b, byte *wrap);
+WOLFSSL_LOCAL w64wrapper w64Sub32(w64wrapper a, word32 b, byte *wrap);
+WOLFSSL_LOCAL byte w64GT(w64wrapper a, w64wrapper b);
+WOLFSSL_LOCAL byte w64IsZero(w64wrapper a);
+WOLFSSL_LOCAL void c64toa(const w64wrapper *a, byte *out);
+WOLFSSL_LOCAL void ato64(const byte *in, w64wrapper *w64);
+WOLFSSL_LOCAL w64wrapper w64From32(word32 hi, word32 lo);
+WOLFSSL_LOCAL byte w64GTE(w64wrapper a, w64wrapper b);
+WOLFSSL_LOCAL byte w64LT(w64wrapper a, w64wrapper b);
+WOLFSSL_LOCAL w64wrapper w64Sub(w64wrapper a, w64wrapper b);
+WOLFSSL_LOCAL void w64Zero(w64wrapper *a);
+
 #endif /* NO_INLINE */
 
 

wolfssl/wolfcrypt/settings.h

@@ -2771,8 +2771,9 @@ extern void uITRON4_free(void *p) ;
     #define NO_SESSION_CACHE_REF
 #endif
 
-/* DTLS v1.3 requires 64-bit number wrappers */
+/* (D)TLS v1.3 requires 64-bit number wrappers */
-#if defined(WOLFSSL_DTLS13) && !defined(WOLFSSL_W64_WRAPPER)
+#if defined(WOLFSSL_TLS13) || defined(WOLFSSL_DTLS_DROP_STATS)
+    #undef WOLFSSL_W64_WRAPPER
     #define WOLFSSL_W64_WRAPPER
 #endif