2 * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include <openssl/ssl.h>
11 #include "internal/quic_record_rx.h"
12 #include "quic_record_shared.h"
13 #include "internal/common.h"
14 #include "internal/list.h"
15 #include "../ssl_local.h"
18 * Mark a packet in a bitfield.
20 * pkt_idx: index of packet within datagram.
22 static ossl_inline void pkt_mark(uint64_t *bitf, size_t pkt_idx)
24 assert(pkt_idx < QUIC_MAX_PKT_PER_URXE);
25 *bitf |= ((uint64_t)1) << pkt_idx;
28 /* Returns 1 if a packet is in the bitfield. */
29 static ossl_inline int pkt_is_marked(const uint64_t *bitf, size_t pkt_idx)
31 assert(pkt_idx < QUIC_MAX_PKT_PER_URXE);
32 return (*bitf & (((uint64_t)1) << pkt_idx)) != 0;
39 * RX Entries (RXEs) store processed (i.e., decrypted) data received from the
40 * network. One RXE is used per received QUIC packet.
42 typedef struct rxe_st RXE;
46 OSSL_LIST_MEMBER(rxe, RXE);
47 size_t data_len, alloc_len, refcount;
49 /* Extra fields for per-packet information. */
50 QUIC_PKT_HDR hdr; /* data/len are decrypted payload */
52 /* Decoded packet number. */
55 /* Addresses copied from URXE. */
58 /* Time we received the packet (not when we processed it). */
61 /* Total length of the datagram which contained this packet. */
65 * alloc_len allocated bytes (of which data_len bytes are valid) follow this
70 DEFINE_LIST_OF(rxe, RXE);
71 typedef OSSL_LIST(rxe) RXE_LIST;
73 static ossl_inline unsigned char *rxe_data(const RXE *e)
75 return (unsigned char *)(e + 1);
86 /* Demux to receive datagrams from. */
89 /* Length of connection IDs used in short-header packets in bytes. */
90 size_t short_conn_id_len;
92 /* Maximum number of deferred datagrams buffered at any one time. */
95 /* Current count of deferred datagrams. */
99 * List of URXEs which are filled with received encrypted data.
100 * These are returned to the DEMUX's free list as they are processed.
102 QUIC_URXE_LIST urx_pending;
105 * List of URXEs which we could not decrypt immediately and which are being
106 * kept in case they can be decrypted later.
108 QUIC_URXE_LIST urx_deferred;
111 * List of RXEs which are not currently in use. These are moved
112 * to the pending list as they are filled.
117 * List of RXEs which are filled with decrypted packets ready to be passed
118 * to the user. A RXE is removed from all lists inside the QRL when passed
119 * to the user, then returned to the free list when the user returns it.
123 /* Largest PN we have received and processed in a given PN space. */
124 QUIC_PN largest_pn[QUIC_PN_SPACE_NUM];
126 /* Per encryption-level state. */
127 OSSL_QRL_ENC_LEVEL_SET el_set;
129 /* Bytes we have received since this counter was last cleared. */
130 uint64_t bytes_received;
133 * Number of forged packets we have received since the QRX was instantiated.
134 * Note that as per RFC 9001, this is connection-level state; it is not per
135 * EL and is not reset by a key update.
137 uint64_t forged_pkt_count;
139 /* Validation callback. */
140 ossl_qrx_early_validation_cb *validation_cb;
141 void *validation_cb_arg;
143 /* Key update callback. */
144 ossl_qrx_key_update_cb *key_update_cb;
145 void *key_update_cb_arg;
147 /* Initial key phase. For debugging use only; always 0 in real use. */
148 unsigned char init_key_phase_bit;
150 /* Message callback related arguments */
151 ossl_msg_cb msg_callback;
152 void *msg_callback_arg;
156 static void qrx_on_rx(QUIC_URXE *urxe, void *arg);
158 OSSL_QRX *ossl_qrx_new(const OSSL_QRX_ARGS *args)
163 if (args->demux == NULL || args->max_deferred == 0)
166 qrx = OPENSSL_zalloc(sizeof(OSSL_QRX));
170 for (i = 0; i < OSSL_NELEM(qrx->largest_pn); ++i)
171 qrx->largest_pn[i] = args->init_largest_pn[i];
173 qrx->libctx = args->libctx;
174 qrx->propq = args->propq;
175 qrx->demux = args->demux;
176 qrx->short_conn_id_len = args->short_conn_id_len;
177 qrx->init_key_phase_bit = args->init_key_phase_bit;
178 qrx->max_deferred = args->max_deferred;
179 qrx->msg_callback = args->msg_callback;
180 qrx->msg_callback_arg = args->msg_callback_arg;
181 qrx->msg_callback_s = args->msg_callback_s;
185 static void qrx_cleanup_rxl(RXE_LIST *l)
189 for (e = ossl_list_rxe_head(l); e != NULL; e = enext) {
190 enext = ossl_list_rxe_next(e);
191 ossl_list_rxe_remove(l, e);
196 static void qrx_cleanup_urxl(OSSL_QRX *qrx, QUIC_URXE_LIST *l)
198 QUIC_URXE *e, *enext;
200 for (e = ossl_list_urxe_head(l); e != NULL; e = enext) {
201 enext = ossl_list_urxe_next(e);
202 ossl_list_urxe_remove(l, e);
203 ossl_quic_demux_release_urxe(qrx->demux, e);
207 void ossl_qrx_free(OSSL_QRX *qrx)
214 /* Unregister from the RX DEMUX. */
215 ossl_quic_demux_unregister_by_cb(qrx->demux, qrx_on_rx, qrx);
217 /* Free RXE queue data. */
218 qrx_cleanup_rxl(&qrx->rx_free);
219 qrx_cleanup_rxl(&qrx->rx_pending);
220 qrx_cleanup_urxl(qrx, &qrx->urx_pending);
221 qrx_cleanup_urxl(qrx, &qrx->urx_deferred);
223 /* Drop keying material and crypto resources. */
224 for (i = 0; i < QUIC_ENC_LEVEL_NUM; ++i)
225 ossl_qrl_enc_level_set_discard(&qrx->el_set, i);
230 void ossl_qrx_inject_urxe(OSSL_QRX *qrx, QUIC_URXE *urxe)
232 /* Initialize our own fields inside the URXE and add to the pending list. */
234 urxe->hpr_removed = 0;
236 ossl_list_urxe_insert_tail(&qrx->urx_pending, urxe);
238 if (qrx->msg_callback != NULL)
239 qrx->msg_callback(0, OSSL_QUIC1_VERSION, SSL3_RT_QUIC_DATAGRAM, urxe + 1,
240 urxe->data_len, qrx->msg_callback_s, qrx->msg_callback_arg);
243 static void qrx_on_rx(QUIC_URXE *urxe, void *arg)
246 ossl_qrx_inject_urxe(qrx, urxe);
249 int ossl_qrx_add_dst_conn_id(OSSL_QRX *qrx,
250 const QUIC_CONN_ID *dst_conn_id)
252 return ossl_quic_demux_register(qrx->demux,
258 int ossl_qrx_remove_dst_conn_id(OSSL_QRX *qrx,
259 const QUIC_CONN_ID *dst_conn_id)
261 return ossl_quic_demux_unregister(qrx->demux, dst_conn_id);
264 static void qrx_requeue_deferred(OSSL_QRX *qrx)
268 while ((e = ossl_list_urxe_head(&qrx->urx_deferred)) != NULL) {
269 ossl_list_urxe_remove(&qrx->urx_deferred, e);
270 ossl_list_urxe_insert_head(&qrx->urx_pending, e);
274 int ossl_qrx_provide_secret(OSSL_QRX *qrx, uint32_t enc_level,
275 uint32_t suite_id, EVP_MD *md,
276 const unsigned char *secret, size_t secret_len)
278 if (enc_level >= QUIC_ENC_LEVEL_NUM)
281 if (!ossl_qrl_enc_level_set_provide_secret(&qrx->el_set,
289 qrx->init_key_phase_bit,
294 * Any packets we previously could not decrypt, we may now be able to
295 * decrypt, so move any datagrams containing deferred packets from the
296 * deferred to the pending queue.
298 qrx_requeue_deferred(qrx);
302 int ossl_qrx_discard_enc_level(OSSL_QRX *qrx, uint32_t enc_level)
304 if (enc_level >= QUIC_ENC_LEVEL_NUM)
307 ossl_qrl_enc_level_set_discard(&qrx->el_set, enc_level);
311 /* Returns 1 if there are one or more pending RXEs. */
312 int ossl_qrx_processed_read_pending(OSSL_QRX *qrx)
314 return !ossl_list_rxe_is_empty(&qrx->rx_pending);
317 /* Returns 1 if there are yet-unprocessed packets. */
318 int ossl_qrx_unprocessed_read_pending(OSSL_QRX *qrx)
320 return !ossl_list_urxe_is_empty(&qrx->urx_pending)
321 || !ossl_list_urxe_is_empty(&qrx->urx_deferred);
324 /* Pop the next pending RXE. Returns NULL if no RXE is pending. */
325 static RXE *qrx_pop_pending_rxe(OSSL_QRX *qrx)
327 RXE *rxe = ossl_list_rxe_head(&qrx->rx_pending);
332 ossl_list_rxe_remove(&qrx->rx_pending, rxe);
336 /* Allocate a new RXE. */
337 static RXE *qrx_alloc_rxe(size_t alloc_len)
341 if (alloc_len >= SIZE_MAX - sizeof(RXE))
344 rxe = OPENSSL_malloc(sizeof(RXE) + alloc_len);
348 ossl_list_rxe_init_elem(rxe);
349 rxe->alloc_len = alloc_len;
356 * Ensures there is at least one RXE in the RX free list, allocating a new entry
357 * if necessary. The returned RXE is in the RX free list; it is not popped.
359 * alloc_len is a hint which may be used to determine the RXE size if allocation
360 * is necessary. Returns NULL on allocation failure.
362 static RXE *qrx_ensure_free_rxe(OSSL_QRX *qrx, size_t alloc_len)
366 if (ossl_list_rxe_head(&qrx->rx_free) != NULL)
367 return ossl_list_rxe_head(&qrx->rx_free);
369 rxe = qrx_alloc_rxe(alloc_len);
373 ossl_list_rxe_insert_tail(&qrx->rx_free, rxe);
378 * Resize the data buffer attached to an RXE to be n bytes in size. The address
379 * of the RXE might change; the new address is returned, or NULL on failure, in
380 * which case the original RXE remains valid.
382 static RXE *qrx_resize_rxe(RXE_LIST *rxl, RXE *rxe, size_t n)
386 /* Should never happen. */
390 if (n >= SIZE_MAX - sizeof(RXE))
393 /* Remove the item from the list to avoid accessing freed memory */
394 p = ossl_list_rxe_prev(rxe);
395 ossl_list_rxe_remove(rxl, rxe);
397 /* Should never resize an RXE which has been handed out. */
398 if (!ossl_assert(rxe->refcount == 0))
402 * NOTE: We do not clear old memory, although it does contain decrypted
405 rxe2 = OPENSSL_realloc(rxe, sizeof(RXE) + n);
407 /* Resize failed, restore old allocation. */
409 ossl_list_rxe_insert_head(rxl, rxe);
411 ossl_list_rxe_insert_after(rxl, p, rxe);
416 ossl_list_rxe_insert_head(rxl, rxe2);
418 ossl_list_rxe_insert_after(rxl, p, rxe2);
425 * Ensure the data buffer attached to an RXE is at least n bytes in size.
426 * Returns NULL on failure.
428 static RXE *qrx_reserve_rxe(RXE_LIST *rxl,
431 if (rxe->alloc_len >= n)
434 return qrx_resize_rxe(rxl, rxe, n);
437 /* Return a RXE handed out to the user back to our freelist. */
438 static void qrx_recycle_rxe(OSSL_QRX *qrx, RXE *rxe)
440 /* RXE should not be in any list */
441 assert(ossl_list_rxe_prev(rxe) == NULL && ossl_list_rxe_next(rxe) == NULL);
443 rxe->pkt.peer = NULL;
444 rxe->pkt.local = NULL;
445 ossl_list_rxe_insert_tail(&qrx->rx_free, rxe);
449 * Given a pointer to a pointer pointing to a buffer and the size of that
450 * buffer, copy the buffer into *prxe, expanding the RXE if necessary (its
451 * pointer may change due to realloc). *pi is the offset in bytes to copy the
452 * buffer to, and on success is updated to be the offset pointing after the
453 * copied buffer. *pptr is updated to point to the new location of the buffer.
455 static int qrx_relocate_buffer(OSSL_QRX *qrx, RXE **prxe, size_t *pi,
456 const unsigned char **pptr, size_t buf_len)
464 if ((rxe = qrx_reserve_rxe(&qrx->rx_free, *prxe, *pi + buf_len)) == NULL)
468 dst = (unsigned char *)rxe_data(rxe) + *pi;
470 memcpy(dst, *pptr, buf_len);
476 static uint32_t qrx_determine_enc_level(const QUIC_PKT_HDR *hdr)
479 case QUIC_PKT_TYPE_INITIAL:
480 return QUIC_ENC_LEVEL_INITIAL;
481 case QUIC_PKT_TYPE_HANDSHAKE:
482 return QUIC_ENC_LEVEL_HANDSHAKE;
483 case QUIC_PKT_TYPE_0RTT:
484 return QUIC_ENC_LEVEL_0RTT;
485 case QUIC_PKT_TYPE_1RTT:
486 return QUIC_ENC_LEVEL_1RTT;
490 case QUIC_PKT_TYPE_RETRY:
491 case QUIC_PKT_TYPE_VERSION_NEG:
492 return QUIC_ENC_LEVEL_INITIAL; /* not used */
496 static uint32_t rxe_determine_pn_space(RXE *rxe)
500 enc_level = qrx_determine_enc_level(&rxe->hdr);
501 return ossl_quic_enc_level_to_pn_space(enc_level);
504 static int qrx_validate_hdr_early(OSSL_QRX *qrx, RXE *rxe,
505 const QUIC_CONN_ID *first_dcid)
507 /* Ensure version is what we want. */
508 if (rxe->hdr.version != QUIC_VERSION_1
509 && rxe->hdr.version != QUIC_VERSION_NONE)
512 /* Clients should never receive 0-RTT packets. */
513 if (rxe->hdr.type == QUIC_PKT_TYPE_0RTT)
516 /* Version negotiation and retry packets must be the first packet. */
517 if (first_dcid != NULL && !ossl_quic_pkt_type_can_share_dgram(rxe->hdr.type))
521 * If this is not the first packet in a datagram, the destination connection
522 * ID must match the one in that packet.
524 if (first_dcid != NULL) {
525 if (!ossl_assert(first_dcid->id_len < QUIC_MAX_CONN_ID_LEN)
526 || !ossl_quic_conn_id_eq(first_dcid,
527 &rxe->hdr.dst_conn_id))
534 /* Validate header and decode PN. */
535 static int qrx_validate_hdr(OSSL_QRX *qrx, RXE *rxe)
537 int pn_space = rxe_determine_pn_space(rxe);
539 if (!ossl_quic_wire_decode_pkt_hdr_pn(rxe->hdr.pn, rxe->hdr.pn_len,
540 qrx->largest_pn[pn_space],
545 * Allow our user to decide whether to discard the packet before we try and
548 if (qrx->validation_cb != NULL
549 && !qrx->validation_cb(rxe->pn, pn_space, qrx->validation_cb_arg))
555 /* Retrieves the correct cipher context for an EL and key phase. */
556 static size_t qrx_get_cipher_ctx_idx(OSSL_QRX *qrx, OSSL_QRL_ENC_LEVEL *el,
558 unsigned char key_phase_bit)
560 if (enc_level != QUIC_ENC_LEVEL_1RTT)
563 if (!ossl_assert(key_phase_bit <= 1))
567 * RFC 9001 requires that we not create timing channels which could reveal
568 * the decrypted value of the Key Phase bit. We usually handle this by
569 * keeping the cipher contexts for both the current and next key epochs
570 * around, so that we just select a cipher context blindly using the key
571 * phase bit, which is time-invariant.
573 * In the COOLDOWN state, we only have one keyslot/cipher context. RFC 9001
574 * suggests an implementation strategy to avoid creating a timing channel in
577 * Endpoints can use randomized packet protection keys in place of
578 * discarded keys when key updates are not yet permitted.
580 * Rather than use a randomised key, we simply use our existing key as it
581 * will fail AEAD verification anyway. This avoids the need to keep around a
582 * dedicated garbage key.
584 * Note: Accessing different cipher contexts is technically not
585 * timing-channel safe due to microarchitectural side channels, but this is
586 * the best we can reasonably do and appears to be directly suggested by the
589 return el->state == QRL_EL_STATE_PROV_COOLDOWN ? el->key_epoch & 1
594 * Tries to decrypt a packet payload.
596 * Returns 1 on success or 0 on failure (which is permanent). The payload is
597 * decrypted from src and written to dst. The buffer dst must be of at least
598 * src_len bytes in length. The actual length of the output in bytes is written
599 * to *dec_len on success, which will always be equal to or less than (usually
600 * less than) src_len.
602 static int qrx_decrypt_pkt_body(OSSL_QRX *qrx, unsigned char *dst,
603 const unsigned char *src,
604 size_t src_len, size_t *dec_len,
605 const unsigned char *aad, size_t aad_len,
606 QUIC_PN pn, uint32_t enc_level,
607 unsigned char key_phase_bit)
610 unsigned char nonce[EVP_MAX_IV_LENGTH];
611 size_t nonce_len, i, cctx_idx;
612 OSSL_QRL_ENC_LEVEL *el = ossl_qrl_enc_level_set_get(&qrx->el_set,
614 EVP_CIPHER_CTX *cctx;
616 if (src_len > INT_MAX || aad_len > INT_MAX)
619 /* We should not have been called if we do not have key material. */
620 if (!ossl_assert(el != NULL))
623 if (el->tag_len >= src_len)
627 * If we have failed to authenticate a certain number of ciphertexts, refuse
628 * to decrypt any more ciphertexts.
630 if (qrx->forged_pkt_count >= ossl_qrl_get_suite_max_forged_pkt(el->suite_id))
633 cctx_idx = qrx_get_cipher_ctx_idx(qrx, el, enc_level, key_phase_bit);
634 if (!ossl_assert(cctx_idx < OSSL_NELEM(el->cctx)))
637 cctx = el->cctx[cctx_idx];
639 /* Construct nonce (nonce=IV ^ PN). */
640 nonce_len = EVP_CIPHER_CTX_get_iv_length(cctx);
641 if (!ossl_assert(nonce_len >= sizeof(QUIC_PN)))
644 memcpy(nonce, el->iv[cctx_idx], nonce_len);
645 for (i = 0; i < sizeof(QUIC_PN); ++i)
646 nonce[nonce_len - i - 1] ^= (unsigned char)(pn >> (i * 8));
648 /* type and key will already have been setup; feed the IV. */
649 if (EVP_CipherInit_ex(cctx, NULL,
650 NULL, NULL, nonce, /*enc=*/0) != 1)
653 /* Feed the AEAD tag we got so the cipher can validate it. */
654 if (EVP_CIPHER_CTX_ctrl(cctx, EVP_CTRL_AEAD_SET_TAG,
656 (unsigned char *)src + src_len - el->tag_len) != 1)
660 if (EVP_CipherUpdate(cctx, NULL, &l, aad, aad_len) != 1)
663 /* Feed encrypted packet body. */
664 if (EVP_CipherUpdate(cctx, dst, &l, src, src_len - el->tag_len) != 1)
667 /* Ensure authentication succeeded. */
668 if (EVP_CipherFinal_ex(cctx, NULL, &l2) != 1) {
669 /* Authentication failed, increment failed auth counter. */
670 ++qrx->forged_pkt_count;
678 static ossl_inline void ignore_res(int x)
683 static void qrx_key_update_initiated(OSSL_QRX *qrx)
685 if (!ossl_qrl_enc_level_set_key_update(&qrx->el_set, QUIC_ENC_LEVEL_1RTT))
688 if (qrx->key_update_cb != NULL)
689 qrx->key_update_cb(qrx->key_update_cb_arg);
692 /* Process a single packet in a datagram. */
693 static int qrx_process_pkt(OSSL_QRX *qrx, QUIC_URXE *urxe,
694 PACKET *pkt, size_t pkt_idx,
695 QUIC_CONN_ID *first_dcid,
699 const unsigned char *eop = NULL;
700 size_t i, aad_len = 0, dec_len = 0;
701 PACKET orig_pkt = *pkt;
702 const unsigned char *sop = PACKET_data(pkt);
704 char need_second_decode = 0, already_processed = 0;
705 QUIC_PKT_HDR_PTRS ptrs;
706 uint32_t pn_space, enc_level;
707 OSSL_QRL_ENC_LEVEL *el = NULL;
710 * Get a free RXE. If we need to allocate a new one, use the packet length
711 * as a good ballpark figure.
713 rxe = qrx_ensure_free_rxe(qrx, PACKET_remaining(pkt));
717 /* Have we already processed this packet? */
718 if (pkt_is_marked(&urxe->processed, pkt_idx))
719 already_processed = 1;
722 * Decode the header into the RXE structure. We first decrypt and read the
723 * unprotected part of the packet header (unless we already removed header
724 * protection, in which case we decode all of it).
726 need_second_decode = !pkt_is_marked(&urxe->hpr_removed, pkt_idx);
727 if (!ossl_quic_wire_decode_pkt_hdr(pkt,
728 qrx->short_conn_id_len,
729 need_second_decode, 0, &rxe->hdr, &ptrs))
733 * Our successful decode above included an intelligible length and the
734 * PACKET is now pointing to the end of the QUIC packet.
736 eop = PACKET_data(pkt);
739 * Make a note of the first packet's DCID so we can later ensure the
740 * destination connection IDs of all packets in a datagram match.
743 *first_dcid = rxe->hdr.dst_conn_id;
746 * Early header validation. Since we now know the packet length, we can also
747 * now skip over it if we already processed it.
749 if (already_processed
750 || !qrx_validate_hdr_early(qrx, rxe, pkt_idx == 0 ? NULL : first_dcid))
752 * Already processed packets are handled identically to malformed
753 * packets; i.e., they are ignored.
757 if (!ossl_quic_pkt_type_is_encrypted(rxe->hdr.type)) {
759 * Version negotiation and retry packets are a special case. They do not
760 * contain a payload which needs decrypting and have no header
764 /* Just copy the payload from the URXE to the RXE. */
765 if ((rxe = qrx_reserve_rxe(&qrx->rx_free, rxe, rxe->hdr.len)) == NULL)
767 * Allocation failure. EOP will be pointing to the end of the
768 * datagram so processing of this datagram will end here.
772 /* We are now committed to returning the packet. */
773 memcpy(rxe_data(rxe), rxe->hdr.data, rxe->hdr.len);
774 pkt_mark(&urxe->processed, pkt_idx);
776 rxe->hdr.data = rxe_data(rxe);
777 rxe->pn = QUIC_PN_INVALID;
779 /* Move RXE to pending. */
780 ossl_list_rxe_remove(&qrx->rx_free, rxe);
781 ossl_list_rxe_insert_tail(&qrx->rx_pending, rxe);
782 return 0; /* success, did not defer */
785 /* Determine encryption level of packet. */
786 enc_level = qrx_determine_enc_level(&rxe->hdr);
788 /* If we do not have keying material for this encryption level yet, defer. */
789 switch (ossl_qrl_enc_level_set_have_el(&qrx->el_set, enc_level)) {
797 /* We already discarded keys for this EL, we will never process this.*/
802 * We will copy any token included in the packet to the start of our RXE
803 * data buffer (so that we don't reference the URXE buffer any more and can
804 * recycle it). Track our position in the RXE buffer by index instead of
805 * pointer as the pointer may change as reallocs occur.
810 * rxe->hdr.data is now pointing at the (encrypted) packet payload. rxe->hdr
811 * also has fields pointing into the PACKET buffer which will be going away
812 * soon (the URXE will be reused for another incoming packet).
814 * Firstly, relocate some of these fields into the RXE as needed.
816 * Relocate token buffer and fix pointer.
818 if (rxe->hdr.type == QUIC_PKT_TYPE_INITIAL
819 && !qrx_relocate_buffer(qrx, &rxe, &i, &rxe->hdr.token,
823 /* Now remove header protection. */
826 el = ossl_qrl_enc_level_set_get(&qrx->el_set, enc_level, 1);
827 assert(el != NULL); /* Already checked above */
829 if (need_second_decode) {
830 if (!ossl_quic_hdr_protector_decrypt(&el->hpr, &ptrs))
834 * We have removed header protection, so don't attempt to do it again if
835 * the packet gets deferred and processed again.
837 pkt_mark(&urxe->hpr_removed, pkt_idx);
839 /* Decode the now unprotected header. */
840 if (ossl_quic_wire_decode_pkt_hdr(pkt, qrx->short_conn_id_len,
841 0, 0, &rxe->hdr, NULL) != 1)
845 /* Validate header and decode PN. */
846 if (!qrx_validate_hdr(qrx, rxe))
849 if (qrx->msg_callback != NULL)
850 qrx->msg_callback(0, OSSL_QUIC1_VERSION, SSL3_RT_QUIC_PACKET, sop,
851 eop - sop - rxe->hdr.len, qrx->msg_callback_s,
852 qrx->msg_callback_arg);
855 * The AAD data is the entire (unprotected) packet header including the PN.
856 * The packet header has been unprotected in place, so we can just reuse the
857 * PACKET buffer. The header ends where the payload begins.
859 aad_len = rxe->hdr.data - sop;
861 /* Ensure the RXE buffer size is adequate for our payload. */
862 if ((rxe = qrx_reserve_rxe(&qrx->rx_free, rxe, rxe->hdr.len + i)) == NULL) {
864 * Allocation failure, treat as malformed and do not bother processing
865 * any further packets in the datagram as they are likely to also
866 * encounter allocation failures.
873 * We decrypt the packet body to immediately after the token at the start of
874 * the RXE buffer (where present).
876 * Do the decryption from the PACKET (which points into URXE memory) to our
877 * RXE payload (single-copy decryption), then fixup the pointers in the
878 * header to point to our new buffer.
880 * If decryption fails this is considered a permanent error; we defer
881 * packets we don't yet have decryption keys for above, so if this fails,
882 * something has gone wrong with the handshake process or a packet has been
885 dst = (unsigned char *)rxe_data(rxe) + i;
886 if (!qrx_decrypt_pkt_body(qrx, dst, rxe->hdr.data, rxe->hdr.len,
887 &dec_len, sop, aad_len, rxe->pn, enc_level,
892 * At this point, we have successfully authenticated the AEAD tag and no
893 * longer need to worry about exposing the Key Phase bit in timing channels.
894 * Check for a Key Phase bit differing from our expectation.
896 if (rxe->hdr.type == QUIC_PKT_TYPE_1RTT
897 && rxe->hdr.key_phase != (el->key_epoch & 1))
898 qrx_key_update_initiated(qrx);
901 * We have now successfully decrypted the packet payload. If there are
902 * additional packets in the datagram, it is possible we will fail to
903 * decrypt them and need to defer them until we have some key material we
904 * don't currently possess. If this happens, the URXE will be moved to the
905 * deferred queue. Since a URXE corresponds to one datagram, which may
906 * contain multiple packets, we must ensure any packets we have already
907 * processed in the URXE are not processed again (this is an RFC
908 * requirement). We do this by marking the nth packet in the datagram as
911 * We are now committed to returning this decrypted packet to the user,
912 * meaning we now consider the packet processed and must mark it
915 pkt_mark(&urxe->processed, pkt_idx);
918 * Update header to point to the decrypted buffer, which may be shorter
919 * due to AEAD tags, block padding, etc.
922 rxe->hdr.len = dec_len;
923 rxe->data_len = dec_len;
924 rxe->datagram_len = datagram_len;
926 /* We processed the PN successfully, so update largest processed PN. */
927 pn_space = rxe_determine_pn_space(rxe);
928 if (rxe->pn > qrx->largest_pn[pn_space])
929 qrx->largest_pn[pn_space] = rxe->pn;
931 /* Copy across network addresses and RX time from URXE to RXE. */
932 rxe->peer = urxe->peer;
933 rxe->local = urxe->local;
934 rxe->time = urxe->time;
936 /* Move RXE to pending. */
937 ossl_list_rxe_remove(&qrx->rx_free, rxe);
938 ossl_list_rxe_insert_tail(&qrx->rx_pending, rxe);
939 return 0; /* success, did not defer; not distinguished from failure */
943 * We cannot process this packet right now (but might be able to later). We
944 * MUST attempt to process any other packets in the datagram, so defer it
947 assert(eop != NULL && eop >= PACKET_data(pkt));
949 * We don't care if this fails as it will just result in the packet being at
950 * the end of the datagram buffer.
952 ignore_res(PACKET_forward(pkt, eop - PACKET_data(pkt)));
953 return 1; /* deferred */
958 * This packet cannot be processed and will never be processable. We
959 * were at least able to decode its header and determine its length, so
960 * we can skip over it and try to process any subsequent packets in the
963 * Mark as processed as an optimization.
965 assert(eop >= PACKET_data(pkt));
966 pkt_mark(&urxe->processed, pkt_idx);
967 /* We don't care if this fails (see above) */
968 ignore_res(PACKET_forward(pkt, eop - PACKET_data(pkt)));
971 * This packet cannot be processed and will never be processable.
972 * Because even its header is not intelligible, we cannot examine any
973 * further packets in the datagram because its length cannot be
976 * Advance over the entire remainder of the datagram, and mark it as
977 * processed gap as an optimization.
979 pkt_mark(&urxe->processed, pkt_idx);
980 /* We don't care if this fails (see above) */
981 ignore_res(PACKET_forward(pkt, PACKET_remaining(pkt)));
983 return 0; /* failure, did not defer; not distinguished from success */
986 /* Process a datagram which was received. */
987 static int qrx_process_datagram(OSSL_QRX *qrx, QUIC_URXE *e,
988 const unsigned char *data,
991 int have_deferred = 0;
994 QUIC_CONN_ID first_dcid = { 255 };
996 qrx->bytes_received += data_len;
998 if (!PACKET_buf_init(&pkt, data, data_len))
1001 for (; PACKET_remaining(&pkt) > 0; ++pkt_idx) {
1003 * A packet smaller than the minimum possible QUIC packet size is not
1004 * considered valid. We also ignore more than a certain number of
1005 * packets within the same datagram.
1007 if (PACKET_remaining(&pkt) < QUIC_MIN_VALID_PKT_LEN
1008 || pkt_idx >= QUIC_MAX_PKT_PER_URXE)
1012 * We note whether packet processing resulted in a deferral since
1013 * this means we need to move the URXE to the deferred list rather
1014 * than the free list after we're finished dealing with it for now.
1016 * However, we don't otherwise care here whether processing succeeded or
1017 * failed, as the RFC says even if a packet in a datagram is malformed,
1018 * we should still try to process any packets following it.
1020 * In the case where the packet is so malformed we can't determine its
1021 * length, qrx_process_pkt will take care of advancing to the end of
1022 * the packet, so we will exit the loop automatically in this case.
1024 if (qrx_process_pkt(qrx, e, &pkt, pkt_idx, &first_dcid, data_len))
1028 /* Only report whether there were any deferrals. */
1029 return have_deferred;
1032 /* Process a single pending URXE. */
1033 static int qrx_process_one_urxe(OSSL_QRX *qrx, QUIC_URXE *e)
1037 /* The next URXE we process should be at the head of the pending list. */
1038 if (!ossl_assert(e == ossl_list_urxe_head(&qrx->urx_pending)))
1042 * Attempt to process the datagram. The return value indicates only if
1043 * processing of the datagram was deferred. If we failed to process the
1044 * datagram, we do not attempt to process it again and silently eat the
1047 was_deferred = qrx_process_datagram(qrx, e, ossl_quic_urxe_data(e),
1051 * Remove the URXE from the pending list and return it to
1052 * either the free or deferred list.
1054 ossl_list_urxe_remove(&qrx->urx_pending, e);
1055 if (was_deferred > 0 &&
1056 (e->deferred || qrx->num_deferred < qrx->max_deferred)) {
1057 ossl_list_urxe_insert_tail(&qrx->urx_deferred, e);
1060 ++qrx->num_deferred;
1065 --qrx->num_deferred;
1067 ossl_quic_demux_release_urxe(qrx->demux, e);
1073 /* Process any pending URXEs to generate pending RXEs. */
1074 static int qrx_process_pending_urxl(OSSL_QRX *qrx)
1078 while ((e = ossl_list_urxe_head(&qrx->urx_pending)) != NULL)
1079 if (!qrx_process_one_urxe(qrx, e))
1085 int ossl_qrx_read_pkt(OSSL_QRX *qrx, OSSL_QRX_PKT **ppkt)
1089 if (!ossl_qrx_processed_read_pending(qrx)) {
1090 if (!qrx_process_pending_urxl(qrx))
1093 if (!ossl_qrx_processed_read_pending(qrx))
1097 rxe = qrx_pop_pending_rxe(qrx);
1098 if (!ossl_assert(rxe != NULL))
1101 assert(rxe->refcount == 0);
1104 rxe->pkt.hdr = &rxe->hdr;
1105 rxe->pkt.pn = rxe->pn;
1106 rxe->pkt.time = rxe->time;
1107 rxe->pkt.datagram_len = rxe->datagram_len;
1109 = BIO_ADDR_family(&rxe->peer) != AF_UNSPEC ? &rxe->peer : NULL;
1111 = BIO_ADDR_family(&rxe->local) != AF_UNSPEC ? &rxe->local : NULL;
1118 void ossl_qrx_pkt_release(OSSL_QRX_PKT *pkt)
1126 assert(rxe->refcount > 0);
1127 if (--rxe->refcount == 0)
1128 qrx_recycle_rxe(pkt->qrx, rxe);
1131 void ossl_qrx_pkt_up_ref(OSSL_QRX_PKT *pkt)
1133 RXE *rxe = (RXE *)pkt;
1135 assert(rxe->refcount > 0);
1139 uint64_t ossl_qrx_get_bytes_received(OSSL_QRX *qrx, int clear)
1141 uint64_t v = qrx->bytes_received;
1144 qrx->bytes_received = 0;
1149 int ossl_qrx_set_early_validation_cb(OSSL_QRX *qrx,
1150 ossl_qrx_early_validation_cb *cb,
1153 qrx->validation_cb = cb;
1154 qrx->validation_cb_arg = cb_arg;
1158 int ossl_qrx_set_key_update_cb(OSSL_QRX *qrx,
1159 ossl_qrx_key_update_cb *cb,
1162 qrx->key_update_cb = cb;
1163 qrx->key_update_cb_arg = cb_arg;
1167 uint64_t ossl_qrx_get_key_epoch(OSSL_QRX *qrx)
1169 OSSL_QRL_ENC_LEVEL *el = ossl_qrl_enc_level_set_get(&qrx->el_set,
1170 QUIC_ENC_LEVEL_1RTT, 1);
1172 return el == NULL ? UINT64_MAX : el->key_epoch;
1175 int ossl_qrx_key_update_timeout(OSSL_QRX *qrx, int normal)
1177 OSSL_QRL_ENC_LEVEL *el = ossl_qrl_enc_level_set_get(&qrx->el_set,
1178 QUIC_ENC_LEVEL_1RTT, 1);
1183 if (el->state == QRL_EL_STATE_PROV_UPDATING
1184 && !ossl_qrl_enc_level_set_key_update_done(&qrx->el_set,
1185 QUIC_ENC_LEVEL_1RTT))
1188 if (normal && el->state == QRL_EL_STATE_PROV_COOLDOWN
1189 && !ossl_qrl_enc_level_set_key_cooldown_done(&qrx->el_set,
1190 QUIC_ENC_LEVEL_1RTT))
1196 uint64_t ossl_qrx_get_cur_forged_pkt_count(OSSL_QRX *qrx)
1198 return qrx->forged_pkt_count;
1201 uint64_t ossl_qrx_get_max_forged_pkt_count(OSSL_QRX *qrx,
1204 OSSL_QRL_ENC_LEVEL *el = ossl_qrl_enc_level_set_get(&qrx->el_set,
1207 return el == NULL ? UINT64_MAX
1208 : ossl_qrl_get_suite_max_forged_pkt(el->suite_id);