mirror of
https://github.com/openssl/openssl.git
synced 2024-12-21 06:09:35 +08:00
4e3d481980
Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/22612)
566 lines
16 KiB
C
566 lines
16 KiB
C
/*
|
|
* Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
|
|
*
|
|
* Licensed under the Apache License 2.0 (the "License"). You may not use
|
|
* this file except in compliance with the License. You can obtain a copy
|
|
* in the file LICENSE in the source distribution or at
|
|
* https://www.openssl.org/source/license.html
|
|
*/
|
|
|
|
#include "internal/quic_srtm.h"
|
|
#include "internal/common.h"
|
|
#include <openssl/lhash.h>
|
|
#include <openssl/core_names.h>
|
|
#include <openssl/rand.h>
|
|
|
|
/*
|
|
* QUIC Stateless Reset Token Manager
|
|
* ==================================
|
|
*/
|
|
typedef struct srtm_item_st SRTM_ITEM;
|
|
|
|
#define BLINDED_SRT_LEN 16
|
|
|
|
DEFINE_LHASH_OF_EX(SRTM_ITEM);
|
|
|
|
/*
|
|
* The SRTM is implemented using two LHASH instances, one matching opaque pointers to
|
|
* an item structure, and another matching a SRT-derived value to an item
|
|
* structure. Multiple items with different seq_num values under a given opaque,
|
|
* and duplicate SRTs, are handled using sorted singly-linked lists.
|
|
*
|
|
* The O(n) insert and lookup performance is tolerated on the basis that the
|
|
* total number of entries for a given opaque (total number of extant CIDs for a
|
|
* connection) should be quite small, and the QUIC protocol allows us to place a
|
|
* hard limit on this via the active_connection_id_limit TPARAM. Thus there is
|
|
* no risk of a large number of SRTs needing to be registered under a given
|
|
* opaque.
|
|
*
|
|
* It is expected one SRTM will exist per QUIC_PORT and track all SRTs across
|
|
* all connections for that QUIC_PORT.
|
|
*/
|
|
struct srtm_item_st {
|
|
SRTM_ITEM *next_by_srt_blinded; /* SORT BY opaque DESC */
|
|
SRTM_ITEM *next_by_seq_num; /* SORT BY seq_num DESC */
|
|
void *opaque; /* \__ unique identity for item */
|
|
uint64_t seq_num; /* / */
|
|
QUIC_STATELESS_RESET_TOKEN srt;
|
|
unsigned char srt_blinded[BLINDED_SRT_LEN]; /* H(srt) */
|
|
|
|
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
uint32_t debug_token;
|
|
#endif
|
|
};
|
|
|
|
struct quic_srtm_st {
|
|
/* Crypto context used to calculate blinded SRTs H(srt). */
|
|
EVP_CIPHER_CTX *blind_ctx; /* kept with key */
|
|
|
|
LHASH_OF(SRTM_ITEM) *items_fwd; /* (opaque) -> SRTM_ITEM */
|
|
LHASH_OF(SRTM_ITEM) *items_rev; /* (H(srt)) -> SRTM_ITEM */
|
|
|
|
/*
|
|
* Monotonically transitions to 1 in event of allocation failure. The only
|
|
* valid operation on such an object is to free it.
|
|
*/
|
|
unsigned int alloc_failed : 1;
|
|
};
|
|
|
|
static unsigned long items_fwd_hash(const SRTM_ITEM *item)
|
|
{
|
|
return (unsigned long)(uintptr_t)item->opaque;
|
|
}
|
|
|
|
static int items_fwd_cmp(const SRTM_ITEM *a, const SRTM_ITEM *b)
|
|
{
|
|
return a->opaque != b->opaque;
|
|
}
|
|
|
|
static unsigned long items_rev_hash(const SRTM_ITEM *item)
|
|
{
|
|
/*
|
|
* srt_blinded has already been through a crypto-grade hash function, so we
|
|
* can just use bits from that.
|
|
*/
|
|
unsigned long l;
|
|
|
|
memcpy(&l, item->srt_blinded, sizeof(l));
|
|
return l;
|
|
}
|
|
|
|
static int items_rev_cmp(const SRTM_ITEM *a, const SRTM_ITEM *b)
|
|
{
|
|
/*
|
|
* We don't need to use CRYPTO_memcmp here as the relationship of
|
|
* srt_blinded to srt is already cryptographically obfuscated.
|
|
*/
|
|
return memcmp(a->srt_blinded, b->srt_blinded, sizeof(a->srt_blinded));
|
|
}
|
|
|
|
static int srtm_check_lh(QUIC_SRTM *srtm, LHASH_OF(SRTM_ITEM) *lh)
|
|
{
|
|
if (lh_SRTM_ITEM_error(lh)) {
|
|
srtm->alloc_failed = 1;
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
QUIC_SRTM *ossl_quic_srtm_new(OSSL_LIB_CTX *libctx, const char *propq)
|
|
{
|
|
QUIC_SRTM *srtm = NULL;
|
|
unsigned char key[16];
|
|
EVP_CIPHER *ecb = NULL;
|
|
|
|
if (RAND_priv_bytes_ex(libctx, key, sizeof(key), sizeof(key) * 8) != 1)
|
|
goto err;
|
|
|
|
if ((srtm = OPENSSL_zalloc(sizeof(*srtm))) == NULL)
|
|
return NULL;
|
|
|
|
/* Use AES-128-ECB as a permutation over 128-bit SRTs. */
|
|
if ((ecb = EVP_CIPHER_fetch(libctx, "AES-128-ECB", propq)) == NULL)
|
|
goto err;
|
|
|
|
if ((srtm->blind_ctx = EVP_CIPHER_CTX_new()) == NULL)
|
|
goto err;
|
|
|
|
if (!EVP_EncryptInit_ex2(srtm->blind_ctx, ecb, key, NULL, NULL))
|
|
goto err;
|
|
|
|
EVP_CIPHER_free(ecb);
|
|
ecb = NULL;
|
|
|
|
/* Create mappings. */
|
|
if ((srtm->items_fwd = lh_SRTM_ITEM_new(items_fwd_hash, items_fwd_cmp)) == NULL
|
|
|| (srtm->items_rev = lh_SRTM_ITEM_new(items_rev_hash, items_rev_cmp)) == NULL)
|
|
goto err;
|
|
|
|
return srtm;
|
|
|
|
err:
|
|
/*
|
|
* No cleansing of key needed as blinding exists only for side channel
|
|
* mitigation.
|
|
*/
|
|
ossl_quic_srtm_free(srtm);
|
|
EVP_CIPHER_free(ecb);
|
|
return NULL;
|
|
}
|
|
|
|
static void srtm_free_each(SRTM_ITEM *ihead)
|
|
{
|
|
SRTM_ITEM *inext, *item = ihead;
|
|
|
|
for (item = item->next_by_seq_num; item != NULL; item = inext) {
|
|
inext = item->next_by_seq_num;
|
|
OPENSSL_free(item);
|
|
}
|
|
|
|
OPENSSL_free(ihead);
|
|
}
|
|
|
|
void ossl_quic_srtm_free(QUIC_SRTM *srtm)
|
|
{
|
|
if (srtm == NULL)
|
|
return;
|
|
|
|
lh_SRTM_ITEM_free(srtm->items_rev);
|
|
if (srtm->items_fwd != NULL) {
|
|
lh_SRTM_ITEM_doall(srtm->items_fwd, srtm_free_each);
|
|
lh_SRTM_ITEM_free(srtm->items_fwd);
|
|
}
|
|
|
|
EVP_CIPHER_CTX_free(srtm->blind_ctx);
|
|
OPENSSL_free(srtm);
|
|
}
|
|
|
|
/*
|
|
* Find a SRTM_ITEM by (opaque, seq_num). Returns NULL if no match.
|
|
* If head is non-NULL, writes the head of the relevant opaque list to *head if
|
|
* there is one.
|
|
* If prev is non-NULL, writes the previous node to *prev or NULL if it is
|
|
* the first item.
|
|
*/
|
|
static SRTM_ITEM *srtm_find(QUIC_SRTM *srtm, void *opaque, uint64_t seq_num,
|
|
SRTM_ITEM **head_p, SRTM_ITEM **prev_p)
|
|
{
|
|
SRTM_ITEM key, *item = NULL, *prev = NULL;
|
|
|
|
key.opaque = opaque;
|
|
|
|
item = lh_SRTM_ITEM_retrieve(srtm->items_fwd, &key);
|
|
if (head_p != NULL)
|
|
*head_p = item;
|
|
|
|
for (; item != NULL; prev = item, item = item->next_by_seq_num)
|
|
if (item->seq_num == seq_num) {
|
|
break;
|
|
} else if (item->seq_num < seq_num) {
|
|
/*
|
|
* List is sorted in descending order so there can't be any match
|
|
* after this.
|
|
*/
|
|
item = NULL;
|
|
break;
|
|
}
|
|
|
|
if (prev_p != NULL)
|
|
*prev_p = prev;
|
|
|
|
return item;
|
|
}
|
|
|
|
/*
|
|
* Inserts a SRTM_ITEM into the singly-linked by-sequence-number linked list.
|
|
* The new head pointer is written to *new_head (which may or may not be
|
|
* unchanged).
|
|
*/
|
|
static void sorted_insert_seq_num(SRTM_ITEM *head, SRTM_ITEM *item, SRTM_ITEM **new_head)
|
|
{
|
|
uint64_t seq_num = item->seq_num;
|
|
SRTM_ITEM *cur = head, **fixup = new_head;
|
|
|
|
*new_head = head;
|
|
|
|
while (cur != NULL && cur->seq_num > seq_num) {
|
|
fixup = &cur->next_by_seq_num;
|
|
cur = cur->next_by_seq_num;
|
|
}
|
|
|
|
item->next_by_seq_num = *fixup;
|
|
*fixup = item;
|
|
}
|
|
|
|
/*
|
|
* Inserts a SRTM_ITEM into the singly-linked by-SRT list.
|
|
* The new head pointer is written to *new_head (which may or may not be
|
|
* unchanged).
|
|
*/
|
|
static void sorted_insert_srt(SRTM_ITEM *head, SRTM_ITEM *item, SRTM_ITEM **new_head)
|
|
{
|
|
uintptr_t opaque = (uintptr_t)item->opaque;
|
|
SRTM_ITEM *cur = head, **fixup = new_head;
|
|
|
|
*new_head = head;
|
|
|
|
while (cur != NULL && (uintptr_t)cur->opaque > opaque) {
|
|
fixup = &cur->next_by_srt_blinded;
|
|
cur = cur->next_by_srt_blinded;
|
|
}
|
|
|
|
item->next_by_srt_blinded = *fixup;
|
|
*fixup = item;
|
|
}
|
|
|
|
/*
|
|
* Computes the blinded SRT value used for internal lookup for side channel
|
|
* mitigation purposes. We compute this once as a cached value when an SRTM_ITEM
|
|
* is formed.
|
|
*/
|
|
static int srtm_compute_blinded(QUIC_SRTM *srtm, SRTM_ITEM *item,
|
|
const QUIC_STATELESS_RESET_TOKEN *token)
|
|
{
|
|
int outl = 0;
|
|
|
|
/*
|
|
* We use AES-128-ECB as a permutation using a random key to facilitate
|
|
* blinding for side-channel purposes. Encrypt the token as a single AES
|
|
* block.
|
|
*/
|
|
if (!EVP_EncryptUpdate(srtm->blind_ctx, item->srt_blinded, &outl,
|
|
(const unsigned char *)token, sizeof(*token)))
|
|
return 0;
|
|
|
|
if (!ossl_assert(outl == sizeof(*token)))
|
|
return 0;
|
|
|
|
return 1;
|
|
}
|
|
|
|
int ossl_quic_srtm_add(QUIC_SRTM *srtm, void *opaque, uint64_t seq_num,
|
|
const QUIC_STATELESS_RESET_TOKEN *token)
|
|
{
|
|
SRTM_ITEM *item = NULL, *head = NULL, *new_head, *r_item;
|
|
|
|
if (srtm->alloc_failed)
|
|
return 0;
|
|
|
|
/* (opaque, seq_num) duplicates not allowed */
|
|
if ((item = srtm_find(srtm, opaque, seq_num, &head, NULL)) != NULL)
|
|
return 0;
|
|
|
|
if ((item = OPENSSL_zalloc(sizeof(*item))) == NULL)
|
|
return 0;
|
|
|
|
item->opaque = opaque;
|
|
item->seq_num = seq_num;
|
|
item->srt = *token;
|
|
if (!srtm_compute_blinded(srtm, item, &item->srt)) {
|
|
OPENSSL_free(item);
|
|
return 0;
|
|
}
|
|
|
|
/* Add to forward mapping. */
|
|
if (head == NULL) {
|
|
/* First item under this opaque */
|
|
lh_SRTM_ITEM_insert(srtm->items_fwd, item);
|
|
if (!srtm_check_lh(srtm, srtm->items_fwd)) {
|
|
OPENSSL_free(item);
|
|
return 0;
|
|
}
|
|
} else {
|
|
sorted_insert_seq_num(head, item, &new_head);
|
|
if (new_head != head) { /* head changed, update in lhash */
|
|
lh_SRTM_ITEM_insert(srtm->items_fwd, new_head);
|
|
if (!srtm_check_lh(srtm, srtm->items_fwd)) {
|
|
OPENSSL_free(item);
|
|
return 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Add to reverse mapping. */
|
|
r_item = lh_SRTM_ITEM_retrieve(srtm->items_rev, item);
|
|
if (r_item == NULL) {
|
|
/* First item under this blinded SRT */
|
|
lh_SRTM_ITEM_insert(srtm->items_rev, item);
|
|
if (!srtm_check_lh(srtm, srtm->items_rev))
|
|
/*
|
|
* Can't free the item now as we would have to undo the insertion
|
|
* into the forward mapping which would require an insert operation
|
|
* to restore the previous value. which might also fail. However,
|
|
* the item will be freed OK when we free the entire SRTM.
|
|
*/
|
|
return 0;
|
|
} else {
|
|
sorted_insert_srt(r_item, item, &new_head);
|
|
if (new_head != r_item) { /* head changed, update in lhash */
|
|
lh_SRTM_ITEM_insert(srtm->items_rev, new_head);
|
|
if (!srtm_check_lh(srtm, srtm->items_rev))
|
|
/* As above. */
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* Remove item from reverse mapping. */
|
|
static int srtm_remove_from_rev(QUIC_SRTM *srtm, SRTM_ITEM *item)
|
|
{
|
|
SRTM_ITEM *rh_item;
|
|
|
|
rh_item = lh_SRTM_ITEM_retrieve(srtm->items_rev, item);
|
|
assert(rh_item != NULL);
|
|
if (rh_item == item) {
|
|
/*
|
|
* Change lhash to point to item after this one, or remove the entry if
|
|
* this is the last one.
|
|
*/
|
|
if (item->next_by_srt_blinded != NULL) {
|
|
lh_SRTM_ITEM_insert(srtm->items_rev, item->next_by_srt_blinded);
|
|
if (!srtm_check_lh(srtm, srtm->items_rev))
|
|
return 0;
|
|
} else {
|
|
lh_SRTM_ITEM_delete(srtm->items_rev, item);
|
|
}
|
|
} else {
|
|
/* Find our entry in the SRT list */
|
|
for (; rh_item->next_by_srt_blinded != item;
|
|
rh_item = rh_item->next_by_srt_blinded);
|
|
rh_item->next_by_srt_blinded = item->next_by_srt_blinded;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int ossl_quic_srtm_remove(QUIC_SRTM *srtm, void *opaque, uint64_t seq_num)
|
|
{
|
|
SRTM_ITEM *item, *prev = NULL;
|
|
|
|
if (srtm->alloc_failed)
|
|
return 0;
|
|
|
|
if ((item = srtm_find(srtm, opaque, seq_num, NULL, &prev)) == NULL)
|
|
/* No match */
|
|
return 0;
|
|
|
|
/* Remove from forward mapping. */
|
|
if (prev == NULL) {
|
|
/*
|
|
* Change lhash to point to item after this one, or remove the entry if
|
|
* this is the last one.
|
|
*/
|
|
if (item->next_by_seq_num != NULL) {
|
|
lh_SRTM_ITEM_insert(srtm->items_fwd, item->next_by_seq_num);
|
|
if (!srtm_check_lh(srtm, srtm->items_fwd))
|
|
return 0;
|
|
} else {
|
|
lh_SRTM_ITEM_delete(srtm->items_fwd, item);
|
|
}
|
|
} else {
|
|
prev->next_by_seq_num = item->next_by_seq_num;
|
|
}
|
|
|
|
/* Remove from reverse mapping. */
|
|
if (!srtm_remove_from_rev(srtm, item))
|
|
return 0;
|
|
|
|
OPENSSL_free(item);
|
|
return 1;
|
|
}
|
|
|
|
int ossl_quic_srtm_cull(QUIC_SRTM *srtm, void *opaque)
|
|
{
|
|
SRTM_ITEM key, *item = NULL, *inext, *ihead;
|
|
|
|
key.opaque = opaque;
|
|
|
|
if (srtm->alloc_failed)
|
|
return 0;
|
|
|
|
if ((ihead = lh_SRTM_ITEM_retrieve(srtm->items_fwd, &key)) == NULL)
|
|
return 1; /* nothing removed is a success condition */
|
|
|
|
for (item = ihead; item != NULL; item = inext) {
|
|
inext = item->next_by_seq_num;
|
|
if (item != ihead) {
|
|
srtm_remove_from_rev(srtm, item);
|
|
OPENSSL_free(item);
|
|
}
|
|
}
|
|
|
|
lh_SRTM_ITEM_delete(srtm->items_fwd, ihead);
|
|
srtm_remove_from_rev(srtm, ihead);
|
|
OPENSSL_free(ihead);
|
|
return 1;
|
|
}
|
|
|
|
int ossl_quic_srtm_lookup(QUIC_SRTM *srtm,
|
|
const QUIC_STATELESS_RESET_TOKEN *token,
|
|
size_t idx,
|
|
void **opaque, uint64_t *seq_num)
|
|
{
|
|
SRTM_ITEM key, *item;
|
|
|
|
if (srtm->alloc_failed)
|
|
return 0;
|
|
|
|
if (!srtm_compute_blinded(srtm, &key, token))
|
|
return 0;
|
|
|
|
item = lh_SRTM_ITEM_retrieve(srtm->items_rev, &key);
|
|
for (; idx > 0 && item != NULL; --idx, item = item->next_by_srt_blinded);
|
|
if (item == NULL)
|
|
return 0;
|
|
|
|
if (opaque != NULL)
|
|
*opaque = item->opaque;
|
|
if (seq_num != NULL)
|
|
*seq_num = item->seq_num;
|
|
|
|
return 1;
|
|
}
|
|
|
|
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
|
|
static uint32_t token_next = 0x5eadbeef;
|
|
static size_t tokens_seen;
|
|
|
|
struct check_args {
|
|
uint32_t token;
|
|
int mode;
|
|
};
|
|
|
|
static void check_mark(SRTM_ITEM *item, void *arg)
|
|
{
|
|
struct check_args *arg_ = arg;
|
|
uint32_t token = arg_->token;
|
|
uint64_t prev_seq_num;
|
|
void *prev_opaque;
|
|
int have_prev = 0;
|
|
|
|
assert(item != NULL);
|
|
|
|
while (item != NULL) {
|
|
if (have_prev) {
|
|
assert(!(item->opaque == prev_opaque && item->seq_num == prev_seq_num));
|
|
if (!arg_->mode)
|
|
assert(item->opaque != prev_opaque || item->seq_num < prev_seq_num);
|
|
}
|
|
|
|
++tokens_seen;
|
|
item->debug_token = token;
|
|
prev_opaque = item->opaque;
|
|
prev_seq_num = item->seq_num;
|
|
have_prev = 1;
|
|
|
|
if (arg_->mode)
|
|
item = item->next_by_srt_blinded;
|
|
else
|
|
item = item->next_by_seq_num;
|
|
}
|
|
}
|
|
|
|
static void check_count(SRTM_ITEM *item, void *arg)
|
|
{
|
|
struct check_args *arg_ = arg;
|
|
uint32_t token = arg_->token;
|
|
|
|
assert(item != NULL);
|
|
|
|
while (item != NULL) {
|
|
++tokens_seen;
|
|
assert(item->debug_token == token);
|
|
|
|
if (arg_->mode)
|
|
item = item->next_by_seq_num;
|
|
else
|
|
item = item->next_by_srt_blinded;
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
void ossl_quic_srtm_check(const QUIC_SRTM *srtm)
|
|
{
|
|
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
|
|
struct check_args args = {0};
|
|
size_t tokens_expected, tokens_expected_old;
|
|
|
|
args.token = token_next;
|
|
++token_next;
|
|
|
|
assert(srtm != NULL);
|
|
assert(srtm->blind_ctx != NULL);
|
|
assert(srtm->items_fwd != NULL);
|
|
assert(srtm->items_rev != NULL);
|
|
|
|
tokens_seen = 0;
|
|
lh_SRTM_ITEM_doall_arg(srtm->items_fwd, check_mark, &args);
|
|
|
|
tokens_expected = tokens_seen;
|
|
tokens_seen = 0;
|
|
lh_SRTM_ITEM_doall_arg(srtm->items_rev, check_count, &args);
|
|
|
|
assert(tokens_seen == tokens_expected);
|
|
tokens_expected_old = tokens_expected;
|
|
|
|
args.token = token_next;
|
|
++token_next;
|
|
|
|
args.mode = 1;
|
|
tokens_seen = 0;
|
|
lh_SRTM_ITEM_doall_arg(srtm->items_rev, check_mark, &args);
|
|
|
|
tokens_expected = tokens_seen;
|
|
tokens_seen = 0;
|
|
lh_SRTM_ITEM_doall_arg(srtm->items_fwd, check_count, &args);
|
|
|
|
assert(tokens_seen == tokens_expected);
|
|
assert(tokens_seen == tokens_expected_old);
|
|
#endif
|
|
}
|