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boringssl / boringssl / d678fbfb4802deac0258a9a53eac960d6e6e1bc5 / . / ssl / ssl_session.cc
blob: 52ce2d1e472af94c573ca99194fa6dac9e780e9c [file] [log] [blame]
/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
* Copyright 2005 Nokia. All rights reserved.
*
* Licensed under the OpenSSL license (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 <openssl/ssl.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <utility>
#include <openssl/err.h>
#include <openssl/hmac.h>
#include <openssl/lhash.h>
#include <openssl/mem.h>
#include <openssl/rand.h>
#include "../crypto/internal.h"
#include "internal.h"
BSSL_NAMESPACE_BEGIN
// The address of this is a magic value, a pointer to which is returned by
// SSL_magic_pending_session_ptr(). It allows a session callback to indicate
// that it needs to asynchronously fetch session information.
static const char g_pending_session_magic = 0;
static CRYPTO_EX_DATA_CLASS g_ex_data_class =
CRYPTO_EX_DATA_CLASS_INIT_WITH_APP_DATA;
static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *session);
static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *session);
UniquePtr<SSL_SESSION> ssl_session_new(const SSL_X509_METHOD *x509_method) {
return MakeUnique<SSL_SESSION>(x509_method);
}
uint32_t ssl_hash_session_id(Span<const uint8_t> session_id) {
// Take the first four bytes of |session_id|. Session IDs are generated by the
// server randomly, so we can assume even using the first four bytes results
// in a good distribution.
uint8_t tmp_storage[sizeof(uint32_t)];
if (session_id.size() < sizeof(tmp_storage)) {
OPENSSL_memset(tmp_storage, 0, sizeof(tmp_storage));
OPENSSL_memcpy(tmp_storage, session_id.data(), session_id.size());
session_id = tmp_storage;
}
uint32_t hash = ((uint32_t)session_id[0]) | ((uint32_t)session_id[1] << 8) |
((uint32_t)session_id[2] << 16) |
((uint32_t)session_id[3] << 24);
return hash;
}
UniquePtr<SSL_SESSION> SSL_SESSION_dup(SSL_SESSION *session, int dup_flags) {
UniquePtr<SSL_SESSION> new_session = ssl_session_new(session->x509_method);
if (!new_session) {
return nullptr;
}
new_session->is_server = session->is_server;
new_session->ssl_version = session->ssl_version;
new_session->is_quic = session->is_quic;
new_session->sid_ctx = session->sid_ctx;
// Copy the key material.
new_session->secret = session->secret;
new_session->cipher = session->cipher;
// Copy authentication state.
if (session->psk_identity != nullptr) {
new_session->psk_identity.reset(
OPENSSL_strdup(session->psk_identity.get()));
if (new_session->psk_identity == nullptr) {
return nullptr;
}
}
if (session->certs != nullptr) {
auto buf_up_ref = [](const CRYPTO_BUFFER *buf) {
CRYPTO_BUFFER_up_ref(const_cast<CRYPTO_BUFFER *>(buf));
return const_cast<CRYPTO_BUFFER *>(buf);
};
new_session->certs.reset(sk_CRYPTO_BUFFER_deep_copy(
session->certs.get(), buf_up_ref, CRYPTO_BUFFER_free));
if (new_session->certs == nullptr) {
return nullptr;
}
}
if (!session->x509_method->session_dup(new_session.get(), session)) {
return nullptr;
}
new_session->verify_result = session->verify_result;
new_session->ocsp_response = UpRef(session->ocsp_response);
new_session->signed_cert_timestamp_list =
UpRef(session->signed_cert_timestamp_list);
OPENSSL_memcpy(new_session->peer_sha256, session->peer_sha256,
SHA256_DIGEST_LENGTH);
new_session->peer_sha256_valid = session->peer_sha256_valid;
new_session->peer_signature_algorithm = session->peer_signature_algorithm;
new_session->timeout = session->timeout;
new_session->auth_timeout = session->auth_timeout;
new_session->time = session->time;
// Copy non-authentication connection properties.
if (dup_flags & SSL_SESSION_INCLUDE_NONAUTH) {
new_session->session_id = session->session_id;
new_session->group_id = session->group_id;
new_session->original_handshake_hash = session->original_handshake_hash;
new_session->ticket_lifetime_hint = session->ticket_lifetime_hint;
new_session->ticket_age_add = session->ticket_age_add;
new_session->ticket_max_early_data = session->ticket_max_early_data;
new_session->extended_master_secret = session->extended_master_secret;
new_session->has_application_settings = session->has_application_settings;
if (!new_session->early_alpn.CopyFrom(session->early_alpn) ||
!new_session->quic_early_data_context.CopyFrom(
session->quic_early_data_context) ||
!new_session->local_application_settings.CopyFrom(
session->local_application_settings) ||
!new_session->peer_application_settings.CopyFrom(
session->peer_application_settings)) {
return nullptr;
}
}
// Copy the ticket.
if (dup_flags & SSL_SESSION_INCLUDE_TICKET &&
!new_session->ticket.CopyFrom(session->ticket)) {
return nullptr;
}
// The new_session does not get a copy of the ex_data.
new_session->not_resumable = true;
return new_session;
}
void ssl_session_rebase_time(SSL *ssl, SSL_SESSION *session) {
OPENSSL_timeval now = ssl_ctx_get_current_time(ssl->ctx.get());
// To avoid overflows and underflows, if we've gone back in time, update the
// time, but mark the session expired.
if (session->time > now.tv_sec) {
session->time = now.tv_sec;
session->timeout = 0;
session->auth_timeout = 0;
return;
}
// Adjust the session time and timeouts. If the session has already expired,
// clamp the timeouts at zero.
uint64_t delta = now.tv_sec - session->time;
session->time = now.tv_sec;
if (session->timeout < delta) {
session->timeout = 0;
} else {
session->timeout -= delta;
}
if (session->auth_timeout < delta) {
session->auth_timeout = 0;
} else {
session->auth_timeout -= delta;
}
}
void ssl_session_renew_timeout(SSL *ssl, SSL_SESSION *session,
uint32_t timeout) {
// Rebase the timestamp relative to the current time so |timeout| is measured
// correctly.
ssl_session_rebase_time(ssl, session);
if (session->timeout > timeout) {
return;
}
session->timeout = timeout;
if (session->timeout > session->auth_timeout) {
session->timeout = session->auth_timeout;
}
}
uint16_t ssl_session_protocol_version(const SSL_SESSION *session) {
uint16_t ret;
if (!ssl_protocol_version_from_wire(&ret, session->ssl_version)) {
// An |SSL_SESSION| will never have an invalid version. This is enforced by
// the parser.
assert(0);
return 0;
}
return ret;
}
const EVP_MD *ssl_session_get_digest(const SSL_SESSION *session) {
return ssl_get_handshake_digest(ssl_session_protocol_version(session),
session->cipher);
}
bool ssl_get_new_session(SSL_HANDSHAKE *hs) {
SSL *const ssl = hs->ssl;
if (ssl->mode & SSL_MODE_NO_SESSION_CREATION) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SESSION_MAY_NOT_BE_CREATED);
return false;
}
UniquePtr<SSL_SESSION> session = ssl_session_new(ssl->ctx->x509_method);
if (session == NULL) {
return false;
}
session->is_server = ssl->server;
session->ssl_version = ssl->s3->version;
session->is_quic = SSL_is_quic(ssl);
// Fill in the time from the |SSL_CTX|'s clock.
OPENSSL_timeval now = ssl_ctx_get_current_time(ssl->ctx.get());
session->time = now.tv_sec;
uint16_t version = ssl_protocol_version(ssl);
if (version >= TLS1_3_VERSION) {
// TLS 1.3 uses tickets as authenticators, so we are willing to use them for
// longer.
session->timeout = ssl->session_ctx->session_psk_dhe_timeout;
session->auth_timeout = SSL_DEFAULT_SESSION_AUTH_TIMEOUT;
} else {
// TLS 1.2 resumption does not incorporate new key material, so we use a
// much shorter timeout.
session->timeout = ssl->session_ctx->session_timeout;
session->auth_timeout = ssl->session_ctx->session_timeout;
}
if (!session->sid_ctx.TryCopyFrom(hs->config->cert->sid_ctx)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return false;
}
// The session is marked not resumable until it is completely filled in.
session->not_resumable = true;
session->verify_result = X509_V_ERR_INVALID_CALL;
hs->new_session = std::move(session);
ssl_set_session(ssl, NULL);
return true;
}
bool ssl_ctx_rotate_ticket_encryption_key(SSL_CTX *ctx) {
OPENSSL_timeval now = ssl_ctx_get_current_time(ctx);
{
// Avoid acquiring a write lock in the common case (i.e. a non-default key
// is used or the default keys have not expired yet).
MutexReadLock lock(&ctx->lock);
if (ctx->ticket_key_current &&
(ctx->ticket_key_current->next_rotation_tv_sec == 0 ||
ctx->ticket_key_current->next_rotation_tv_sec > now.tv_sec) &&
(!ctx->ticket_key_prev ||
ctx->ticket_key_prev->next_rotation_tv_sec > now.tv_sec)) {
return true;
}
}
MutexWriteLock lock(&ctx->lock);
if (!ctx->ticket_key_current ||
(ctx->ticket_key_current->next_rotation_tv_sec != 0 &&
ctx->ticket_key_current->next_rotation_tv_sec <= now.tv_sec)) {
// The current key has not been initialized or it is expired.
auto new_key = bssl::MakeUnique<TicketKey>();
if (!new_key) {
return false;
}
RAND_bytes(new_key->name, 16);
RAND_bytes(new_key->hmac_key, 16);
RAND_bytes(new_key->aes_key, 16);
new_key->next_rotation_tv_sec =
now.tv_sec + SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL;
if (ctx->ticket_key_current) {
// The current key expired. Rotate it to prev and bump up its rotation
// timestamp. Note that even with the new rotation time it may still be
// expired and get dropped below.
ctx->ticket_key_current->next_rotation_tv_sec +=
SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL;
ctx->ticket_key_prev = std::move(ctx->ticket_key_current);
}
ctx->ticket_key_current = std::move(new_key);
}
// Drop an expired prev key.
if (ctx->ticket_key_prev &&
ctx->ticket_key_prev->next_rotation_tv_sec <= now.tv_sec) {
ctx->ticket_key_prev.reset();
}
return true;
}
static int ssl_encrypt_ticket_with_cipher_ctx(SSL_HANDSHAKE *hs, CBB *out,
const uint8_t *session_buf,
size_t session_len) {
ScopedEVP_CIPHER_CTX ctx;
ScopedHMAC_CTX hctx;
// If the session is too long, decline to send a ticket.
static const size_t kMaxTicketOverhead =
16 + EVP_MAX_IV_LENGTH + EVP_MAX_BLOCK_LENGTH + EVP_MAX_MD_SIZE;
if (session_len > 0xffff - kMaxTicketOverhead) {
return 1;
}
// Initialize HMAC and cipher contexts. If callback present it does all the
// work otherwise use generated values from parent ctx.
SSL_CTX *tctx = hs->ssl->session_ctx.get();
uint8_t iv[EVP_MAX_IV_LENGTH];
uint8_t key_name[16];
if (tctx->ticket_key_cb != NULL) {
int ret = tctx->ticket_key_cb(hs->ssl, key_name, iv, ctx.get(), hctx.get(),
1 /* encrypt */);
if (ret < 0) {
return 0;
}
if (ret == 0) {
// The caller requested to send no ticket, so write nothing to |out|.
return 1;
}
} else {
// Rotate ticket key if necessary.
if (!ssl_ctx_rotate_ticket_encryption_key(tctx)) {
return 0;
}
MutexReadLock lock(&tctx->lock);
if (!RAND_bytes(iv, 16) ||
!EVP_EncryptInit_ex(ctx.get(), EVP_aes_128_cbc(), NULL,
tctx->ticket_key_current->aes_key, iv) ||
!HMAC_Init_ex(hctx.get(), tctx->ticket_key_current->hmac_key, 16,
tlsext_tick_md(), NULL)) {
return 0;
}
OPENSSL_memcpy(key_name, tctx->ticket_key_current->name, 16);
}
uint8_t *ptr;
if (!CBB_add_bytes(out, key_name, 16) ||
!CBB_add_bytes(out, iv, EVP_CIPHER_CTX_iv_length(ctx.get())) ||
!CBB_reserve(out, &ptr, session_len + EVP_MAX_BLOCK_LENGTH)) {
return 0;
}
size_t total = 0;
#if defined(BORINGSSL_UNSAFE_FUZZER_MODE)
OPENSSL_memcpy(ptr, session_buf, session_len);
total = session_len;
#else
int len;
if (!EVP_EncryptUpdate(ctx.get(), ptr + total, &len, session_buf,
session_len)) {
return 0;
}
total += len;
if (!EVP_EncryptFinal_ex(ctx.get(), ptr + total, &len)) {
return 0;
}
total += len;
#endif
if (!CBB_did_write(out, total)) {
return 0;
}
unsigned hlen;
if (!HMAC_Update(hctx.get(), CBB_data(out), CBB_len(out)) || //
!CBB_reserve(out, &ptr, EVP_MAX_MD_SIZE) || //
!HMAC_Final(hctx.get(), ptr, &hlen) || //
!CBB_did_write(out, hlen)) {
return 0;
}
return 1;
}
static int ssl_encrypt_ticket_with_method(SSL_HANDSHAKE *hs, CBB *out,
const uint8_t *session_buf,
size_t session_len) {
SSL *const ssl = hs->ssl;
const SSL_TICKET_AEAD_METHOD *method = ssl->session_ctx->ticket_aead_method;
const size_t max_overhead = method->max_overhead(ssl);
const size_t max_out = session_len + max_overhead;
if (max_out < max_overhead) {
OPENSSL_PUT_ERROR(SSL, ERR_R_OVERFLOW);
return 0;
}
uint8_t *ptr;
if (!CBB_reserve(out, &ptr, max_out)) {
return 0;
}
size_t out_len;
if (!method->seal(ssl, ptr, &out_len, max_out, session_buf, session_len)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_TICKET_ENCRYPTION_FAILED);
return 0;
}
if (!CBB_did_write(out, out_len)) {
return 0;
}
return 1;
}
bool ssl_encrypt_ticket(SSL_HANDSHAKE *hs, CBB *out,
const SSL_SESSION *session) {
// Serialize the SSL_SESSION to be encoded into the ticket.
uint8_t *session_buf = nullptr;
size_t session_len;
if (!SSL_SESSION_to_bytes_for_ticket(session, &session_buf, &session_len)) {
return false;
}
bssl::UniquePtr<uint8_t> free_session_buf(session_buf);
if (hs->ssl->session_ctx->ticket_aead_method) {
return ssl_encrypt_ticket_with_method(hs, out, session_buf, session_len);
} else {
return ssl_encrypt_ticket_with_cipher_ctx(hs, out, session_buf,
session_len);
}
}
SSLSessionType ssl_session_get_type(const SSL_SESSION *session) {
if (session->not_resumable) {
return SSLSessionType::kNotResumable;
}
if (ssl_session_protocol_version(session) >= TLS1_3_VERSION) {
return session->ticket.empty() ? SSLSessionType::kNotResumable
: SSLSessionType::kPreSharedKey;
}
if (!session->ticket.empty()) {
return SSLSessionType::kTicket;
}
if (!session->session_id.empty()) {
return SSLSessionType::kID;
}
return SSLSessionType::kNotResumable;
}
bool ssl_session_is_context_valid(const SSL_HANDSHAKE *hs,
const SSL_SESSION *session) {
return session != nullptr &&
MakeConstSpan(session->sid_ctx) == hs->config->cert->sid_ctx;
}
bool ssl_session_is_time_valid(const SSL *ssl, const SSL_SESSION *session) {
if (session == NULL) {
return false;
}
OPENSSL_timeval now = ssl_ctx_get_current_time(ssl->ctx.get());
// Reject tickets from the future to avoid underflow.
if (now.tv_sec < session->time) {
return false;
}
return session->timeout > now.tv_sec - session->time;
}
bool ssl_session_is_resumable(const SSL_HANDSHAKE *hs,
const SSL_SESSION *session) {
const SSL *const ssl = hs->ssl;
return ssl_session_is_context_valid(hs, session) &&
// The session must have been created by the same type of end point as
// we're now using it with.
ssl->server == session->is_server &&
// The session must not be expired.
ssl_session_is_time_valid(ssl, session) &&
// Only resume if the session's version matches the negotiated
// version.
ssl->s3->version == session->ssl_version &&
// Only resume if the session's cipher matches the negotiated one. This
// is stricter than necessary for TLS 1.3, which allows cross-cipher
// resumption if the PRF hashes match. We require an exact match for
// simplicity. If loosening this, the 0-RTT accept logic must be
// updated to check the cipher.
hs->new_cipher == session->cipher &&
// If the session contains a client certificate (either the full
// certificate or just the hash) then require that the form of the
// certificate matches the current configuration.
((sk_CRYPTO_BUFFER_num(session->certs.get()) == 0 &&
!session->peer_sha256_valid) ||
session->peer_sha256_valid ==
hs->config->retain_only_sha256_of_client_certs) &&
// Only resume if the underlying transport protocol hasn't changed.
// This is to prevent cross-protocol resumption between QUIC and TCP.
SSL_is_quic(ssl) == int{session->is_quic};
}
// ssl_lookup_session looks up |session_id| in the session cache and sets
// |*out_session| to an |SSL_SESSION| object if found.
static enum ssl_hs_wait_t ssl_lookup_session(
SSL_HANDSHAKE *hs, UniquePtr<SSL_SESSION> *out_session,
Span<const uint8_t> session_id) {
SSL *const ssl = hs->ssl;
out_session->reset();
if (session_id.empty() || session_id.size() > SSL_MAX_SSL_SESSION_ID_LENGTH) {
return ssl_hs_ok;
}
UniquePtr<SSL_SESSION> session;
// Try the internal cache, if it exists.
if (!(ssl->session_ctx->session_cache_mode &
SSL_SESS_CACHE_NO_INTERNAL_LOOKUP)) {
uint32_t hash = ssl_hash_session_id(session_id);
auto cmp = [](const void *key, const SSL_SESSION *sess) -> int {
Span<const uint8_t> key_id =
*reinterpret_cast<const Span<const uint8_t> *>(key);
return key_id == sess->session_id ? 0 : 1;
};
MutexReadLock lock(&ssl->session_ctx->lock);
// |lh_SSL_SESSION_retrieve_key| returns a non-owning pointer.
session = UpRef(lh_SSL_SESSION_retrieve_key(ssl->session_ctx->sessions,
&session_id, hash, cmp));
// TODO(davidben): This should probably move it to the front of the list.
}
// Fall back to the external cache, if it exists.
if (!session && ssl->session_ctx->get_session_cb != nullptr) {
int copy = 1;
session.reset(ssl->session_ctx->get_session_cb(ssl, session_id.data(),
session_id.size(), &copy));
if (!session) {
return ssl_hs_ok;
}
if (session.get() == SSL_magic_pending_session_ptr()) {
session.release(); // This pointer is not actually owned.
return ssl_hs_pending_session;
}
// Increment reference count now if the session callback asks us to do so
// (note that if the session structures returned by the callback are shared
// between threads, it must handle the reference count itself [i.e. copy ==
// 0], or things won't be thread-safe).
if (copy) {
SSL_SESSION_up_ref(session.get());
}
// Add the externally cached session to the internal cache if necessary.
if (!(ssl->session_ctx->session_cache_mode &
SSL_SESS_CACHE_NO_INTERNAL_STORE)) {
SSL_CTX_add_session(ssl->session_ctx.get(), session.get());
}
}
if (session && !ssl_session_is_time_valid(ssl, session.get())) {
// The session was from the cache, so remove it.
SSL_CTX_remove_session(ssl->session_ctx.get(), session.get());
session.reset();
}
*out_session = std::move(session);
return ssl_hs_ok;
}
enum ssl_hs_wait_t ssl_get_prev_session(SSL_HANDSHAKE *hs,
UniquePtr<SSL_SESSION> *out_session,
bool *out_tickets_supported,
bool *out_renew_ticket,
const SSL_CLIENT_HELLO *client_hello) {
// This is used only by servers.
assert(hs->ssl->server);
UniquePtr<SSL_SESSION> session;
bool renew_ticket = false;
// If tickets are disabled, always behave as if no tickets are present.
CBS ticket;
const bool tickets_supported =
!(SSL_get_options(hs->ssl) & SSL_OP_NO_TICKET) &&
ssl_client_hello_get_extension(client_hello, &ticket,
TLSEXT_TYPE_session_ticket);
if (tickets_supported && CBS_len(&ticket) != 0) {
switch (ssl_process_ticket(hs, &session, &renew_ticket, ticket,
MakeConstSpan(client_hello->session_id,
client_hello->session_id_len))) {
case ssl_ticket_aead_success:
break;
case ssl_ticket_aead_ignore_ticket:
assert(!session);
break;
case ssl_ticket_aead_error:
return ssl_hs_error;
case ssl_ticket_aead_retry:
return ssl_hs_pending_ticket;
}
} else {
// The client didn't send a ticket, so the session ID is a real ID.
enum ssl_hs_wait_t lookup_ret = ssl_lookup_session(
hs, &session,
MakeConstSpan(client_hello->session_id, client_hello->session_id_len));
if (lookup_ret != ssl_hs_ok) {
return lookup_ret;
}
}
*out_session = std::move(session);
*out_tickets_supported = tickets_supported;
*out_renew_ticket = renew_ticket;
return ssl_hs_ok;
}
static bool remove_session(SSL_CTX *ctx, SSL_SESSION *session, bool lock) {
if (session == nullptr || session->session_id.empty()) {
return false;
}
if (lock) {
CRYPTO_MUTEX_lock_write(&ctx->lock);
}
SSL_SESSION *found_session = lh_SSL_SESSION_retrieve(ctx->sessions, session);
bool found = found_session == session;
if (found) {
found_session = lh_SSL_SESSION_delete(ctx->sessions, session);
SSL_SESSION_list_remove(ctx, session);
}
if (lock) {
CRYPTO_MUTEX_unlock_write(&ctx->lock);
}
if (found) {
// TODO(https://crbug.com/boringssl/251): Callbacks should not be called
// under a lock.
if (ctx->remove_session_cb != nullptr) {
ctx->remove_session_cb(ctx, found_session);
}
SSL_SESSION_free(found_session);
}
return found;
}
void ssl_set_session(SSL *ssl, SSL_SESSION *session) {
if (ssl->session.get() == session) {
return;
}
ssl->session = UpRef(session);
}
// locked by SSL_CTX in the calling function
static void SSL_SESSION_list_remove(SSL_CTX *ctx, SSL_SESSION *session) {
if (session->next == NULL || session->prev == NULL) {
return;
}
if (session->next == (SSL_SESSION *)&ctx->session_cache_tail) {
// last element in list
if (session->prev == (SSL_SESSION *)&ctx->session_cache_head) {
// only one element in list
ctx->session_cache_head = NULL;
ctx->session_cache_tail = NULL;
} else {
ctx->session_cache_tail = session->prev;
session->prev->next = (SSL_SESSION *)&(ctx->session_cache_tail);
}
} else {
if (session->prev == (SSL_SESSION *)&ctx->session_cache_head) {
// first element in list
ctx->session_cache_head = session->next;
session->next->prev = (SSL_SESSION *)&(ctx->session_cache_head);
} else { // middle of list
session->next->prev = session->prev;
session->prev->next = session->next;
}
}
session->prev = session->next = NULL;
}
static void SSL_SESSION_list_add(SSL_CTX *ctx, SSL_SESSION *session) {
if (session->next != NULL && session->prev != NULL) {
SSL_SESSION_list_remove(ctx, session);
}
if (ctx->session_cache_head == NULL) {
ctx->session_cache_head = session;
ctx->session_cache_tail = session;
session->prev = (SSL_SESSION *)&(ctx->session_cache_head);
session->next = (SSL_SESSION *)&(ctx->session_cache_tail);
} else {
session->next = ctx->session_cache_head;
session->next->prev = session;
session->prev = (SSL_SESSION *)&(ctx->session_cache_head);
ctx->session_cache_head = session;
}
}
static bool add_session_locked(SSL_CTX *ctx, UniquePtr<SSL_SESSION> session) {
SSL_SESSION *new_session = session.get();
SSL_SESSION *old_session;
if (!lh_SSL_SESSION_insert(ctx->sessions, &old_session, new_session)) {
return false;
}
// |ctx->sessions| took ownership of |new_session| and gave us back a
// reference to |old_session|. (|old_session| may be the same as
// |new_session|, in which case we traded identical references with
// |ctx->sessions|.)
session.release();
session.reset(old_session);
if (old_session != nullptr) {
if (old_session == new_session) {
// |session| was already in the cache. There are no linked list pointers
// to update.
return false;
}
// There was a session ID collision. |old_session| was replaced with
// |session| in the hash table, so |old_session| must be removed from the
// linked list to match.
SSL_SESSION_list_remove(ctx, old_session);
}
// This does not increment the reference count. Although |session| is inserted
// into two structures (a doubly-linked list and the hash table), |ctx| only
// takes one reference.
SSL_SESSION_list_add(ctx, new_session);
// Enforce any cache size limits.
if (SSL_CTX_sess_get_cache_size(ctx) > 0) {
while (lh_SSL_SESSION_num_items(ctx->sessions) >
SSL_CTX_sess_get_cache_size(ctx)) {
if (!remove_session(ctx, ctx->session_cache_tail,
/*lock=*/false)) {
break;
}
}
}
return true;
}
void ssl_update_cache(SSL *ssl) {
SSL_CTX *ctx = ssl->session_ctx.get();
SSL_SESSION *session = ssl->s3->established_session.get();
int mode = SSL_is_server(ssl) ? SSL_SESS_CACHE_SERVER : SSL_SESS_CACHE_CLIENT;
if (!SSL_SESSION_is_resumable(session) ||
(ctx->session_cache_mode & mode) != mode) {
return;
}
// Clients never use the internal session cache.
if (ssl->server &&
!(ctx->session_cache_mode & SSL_SESS_CACHE_NO_INTERNAL_STORE)) {
UniquePtr<SSL_SESSION> ref = UpRef(session);
bool remove_expired_sessions = false;
{
MutexWriteLock lock(&ctx->lock);
add_session_locked(ctx, std::move(ref));
if (!(ctx->session_cache_mode & SSL_SESS_CACHE_NO_AUTO_CLEAR)) {
// Automatically flush the internal session cache every 255 connections.
ctx->handshakes_since_cache_flush++;
if (ctx->handshakes_since_cache_flush >= 255) {
remove_expired_sessions = true;
ctx->handshakes_since_cache_flush = 0;
}
}
}
if (remove_expired_sessions) {
// |SSL_CTX_flush_sessions| takes the lock we just released. We could
// merge the critical sections, but we'd then call user code under a
// lock, or compute |now| earlier, even when not flushing.
OPENSSL_timeval now = ssl_ctx_get_current_time(ssl->ctx.get());
SSL_CTX_flush_sessions(ctx, now.tv_sec);
}
}
if (ctx->new_session_cb != nullptr) {
UniquePtr<SSL_SESSION> ref = UpRef(session);
if (ctx->new_session_cb(ssl, ref.get())) {
// |new_session_cb|'s return value signals whether it took ownership.
ref.release();
}
}
}
BSSL_NAMESPACE_END
using namespace bssl;
ssl_session_st::ssl_session_st(const SSL_X509_METHOD *method)
: RefCounted(CheckSubClass()),
x509_method(method),
extended_master_secret(false),
peer_sha256_valid(false),
not_resumable(false),
ticket_age_add_valid(false),
is_server(false),
is_quic(false),
has_application_settings(false) {
CRYPTO_new_ex_data(&ex_data);
time = ::time(nullptr);
}
ssl_session_st::~ssl_session_st() {
CRYPTO_free_ex_data(&g_ex_data_class, this, &ex_data);
x509_method->session_clear(this);
}
SSL_SESSION *SSL_SESSION_new(const SSL_CTX *ctx) {
return ssl_session_new(ctx->x509_method).release();
}
int SSL_SESSION_up_ref(SSL_SESSION *session) {
session->UpRefInternal();
return 1;
}
void SSL_SESSION_free(SSL_SESSION *session) {
if (session == nullptr) {
return;
}
session->DecRefInternal();
}
const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
unsigned *out_len) {
if (out_len != NULL) {
*out_len = session->session_id.size();
}
return session->session_id.data();
}
int SSL_SESSION_set1_id(SSL_SESSION *session, const uint8_t *sid,
size_t sid_len) {
if (!session->session_id.TryCopyFrom(MakeConstSpan(sid, sid_len))) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_SESSION_ID_TOO_LONG);
return 0;
}
return 1;
}
uint32_t SSL_SESSION_get_timeout(const SSL_SESSION *session) {
return session->timeout;
}
uint64_t SSL_SESSION_get_time(const SSL_SESSION *session) {
if (session == NULL) {
// NULL should crash, but silently accept it here for compatibility.
return 0;
}
return session->time;
}
X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session) {
return session->x509_peer;
}
const STACK_OF(CRYPTO_BUFFER) *SSL_SESSION_get0_peer_certificates(
const SSL_SESSION *session) {
return session->certs.get();
}
void SSL_SESSION_get0_signed_cert_timestamp_list(const SSL_SESSION *session,
const uint8_t **out,
size_t *out_len) {
if (session->signed_cert_timestamp_list) {
*out = CRYPTO_BUFFER_data(session->signed_cert_timestamp_list.get());
*out_len = CRYPTO_BUFFER_len(session->signed_cert_timestamp_list.get());
} else {
*out = nullptr;
*out_len = 0;
}
}
void SSL_SESSION_get0_ocsp_response(const SSL_SESSION *session,
const uint8_t **out, size_t *out_len) {
if (session->ocsp_response) {
*out = CRYPTO_BUFFER_data(session->ocsp_response.get());
*out_len = CRYPTO_BUFFER_len(session->ocsp_response.get());
} else {
*out = nullptr;
*out_len = 0;
}
}
size_t SSL_SESSION_get_master_key(const SSL_SESSION *session, uint8_t *out,
size_t max_out) {
if (max_out == 0) {
return session->secret.size();
}
if (max_out > session->secret.size()) {
max_out = session->secret.size();
}
OPENSSL_memcpy(out, session->secret.data(), max_out);
return max_out;
}
uint64_t SSL_SESSION_set_time(SSL_SESSION *session, uint64_t time) {
if (session == NULL) {
return 0;
}
session->time = time;
return time;
}
uint32_t SSL_SESSION_set_timeout(SSL_SESSION *session, uint32_t timeout) {
if (session == NULL) {
return 0;
}
session->timeout = timeout;
session->auth_timeout = timeout;
return 1;
}
const uint8_t *SSL_SESSION_get0_id_context(const SSL_SESSION *session,
unsigned *out_len) {
if (out_len != NULL) {
*out_len = session->sid_ctx.size();
}
return session->sid_ctx.data();
}
int SSL_SESSION_set1_id_context(SSL_SESSION *session, const uint8_t *sid_ctx,
size_t sid_ctx_len) {
if (!session->sid_ctx.TryCopyFrom(MakeConstSpan(sid_ctx, sid_ctx_len))) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG);
return 0;
}
return 1;
}
int SSL_SESSION_should_be_single_use(const SSL_SESSION *session) {
return ssl_session_protocol_version(session) >= TLS1_3_VERSION;
}
int SSL_SESSION_is_resumable(const SSL_SESSION *session) {
return ssl_session_get_type(session) != SSLSessionType::kNotResumable;
}
int SSL_SESSION_has_ticket(const SSL_SESSION *session) {
return !session->ticket.empty();
}
void SSL_SESSION_get0_ticket(const SSL_SESSION *session,
const uint8_t **out_ticket, size_t *out_len) {
if (out_ticket != nullptr) {
*out_ticket = session->ticket.data();
}
*out_len = session->ticket.size();
}
int SSL_SESSION_set_ticket(SSL_SESSION *session, const uint8_t *ticket,
size_t ticket_len) {
return session->ticket.CopyFrom(MakeConstSpan(ticket, ticket_len));
}
uint32_t SSL_SESSION_get_ticket_lifetime_hint(const SSL_SESSION *session) {
return session->ticket_lifetime_hint;
}
const SSL_CIPHER *SSL_SESSION_get0_cipher(const SSL_SESSION *session) {
return session->cipher;
}
int SSL_SESSION_has_peer_sha256(const SSL_SESSION *session) {
return session->peer_sha256_valid;
}
void SSL_SESSION_get0_peer_sha256(const SSL_SESSION *session,
const uint8_t **out_ptr, size_t *out_len) {
if (session->peer_sha256_valid) {
*out_ptr = session->peer_sha256;
*out_len = sizeof(session->peer_sha256);
} else {
*out_ptr = nullptr;
*out_len = 0;
}
}
int SSL_SESSION_early_data_capable(const SSL_SESSION *session) {
return ssl_session_protocol_version(session) >= TLS1_3_VERSION &&
session->ticket_max_early_data != 0;
}
SSL_SESSION *SSL_SESSION_copy_without_early_data(SSL_SESSION *session) {
if (!SSL_SESSION_early_data_capable(session)) {
return UpRef(session).release();
}
bssl::UniquePtr<SSL_SESSION> copy =
SSL_SESSION_dup(session, SSL_SESSION_DUP_ALL);
if (!copy) {
return nullptr;
}
copy->ticket_max_early_data = 0;
// Copied sessions are non-resumable until they're completely filled in.
copy->not_resumable = session->not_resumable;
assert(!SSL_SESSION_early_data_capable(copy.get()));
return copy.release();
}
SSL_SESSION *SSL_magic_pending_session_ptr(void) {
return (SSL_SESSION *)&g_pending_session_magic;
}
SSL_SESSION *SSL_get_session(const SSL *ssl) {
// Once the initially handshake completes, we return the most recently
// established session. In particular, if there is a pending renegotiation, we
// do not return information about it until it completes.
//
// Code in the handshake must either use |hs->new_session| (if updating a
// partial session) or |ssl_handshake_session| (if trying to query properties
// consistently across TLS 1.2 resumption and other handshakes).
if (ssl->s3->established_session != nullptr) {
return ssl->s3->established_session.get();
}
// Otherwise, we must be in the initial handshake.
SSL_HANDSHAKE *hs = ssl->s3->hs.get();
assert(hs != nullptr);
assert(!ssl->s3->initial_handshake_complete);
// Return the 0-RTT session, if in the 0-RTT state. While the handshake has
// not actually completed, the public accessors all report properties as if
// it has.
if (hs->early_session) {
return hs->early_session.get();
}
// Otherwise, return the partial session.
return (SSL_SESSION *)ssl_handshake_session(hs);
}
SSL_SESSION *SSL_get1_session(SSL *ssl) {
SSL_SESSION *ret = SSL_get_session(ssl);
if (ret != NULL) {
SSL_SESSION_up_ref(ret);
}
return ret;
}
int SSL_SESSION_get_ex_new_index(long argl, void *argp,
CRYPTO_EX_unused *unused,
CRYPTO_EX_dup *dup_unused,
CRYPTO_EX_free *free_func) {
return CRYPTO_get_ex_new_index_ex(&g_ex_data_class, argl, argp, free_func);
}
int SSL_SESSION_set_ex_data(SSL_SESSION *session, int idx, void *arg) {
return CRYPTO_set_ex_data(&session->ex_data, idx, arg);
}
void *SSL_SESSION_get_ex_data(const SSL_SESSION *session, int idx) {
return CRYPTO_get_ex_data(&session->ex_data, idx);
}
int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session) {
UniquePtr<SSL_SESSION> owned_session = UpRef(session);
MutexWriteLock lock(&ctx->lock);
return add_session_locked(ctx, std::move(owned_session));
}
int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session) {
return remove_session(ctx, session, /*lock=*/true);
}
int SSL_set_session(SSL *ssl, SSL_SESSION *session) {
// SSL_set_session may only be called before the handshake has started.
if (ssl->s3->initial_handshake_complete || //
ssl->s3->hs == NULL || //
ssl->s3->hs->state != 0) {
abort();
}
ssl_set_session(ssl, session);
return 1;
}
uint32_t SSL_CTX_set_timeout(SSL_CTX *ctx, uint32_t timeout) {
if (ctx == NULL) {
return 0;
}
// Historically, zero was treated as |SSL_DEFAULT_SESSION_TIMEOUT|.
if (timeout == 0) {
timeout = SSL_DEFAULT_SESSION_TIMEOUT;
}
uint32_t old_timeout = ctx->session_timeout;
ctx->session_timeout = timeout;
return old_timeout;
}
uint32_t SSL_CTX_get_timeout(const SSL_CTX *ctx) {
if (ctx == NULL) {
return 0;
}
return ctx->session_timeout;
}
void SSL_CTX_set_session_psk_dhe_timeout(SSL_CTX *ctx, uint32_t timeout) {
ctx->session_psk_dhe_timeout = timeout;
}
typedef struct timeout_param_st {
SSL_CTX *ctx;
uint64_t time;
LHASH_OF(SSL_SESSION) *cache;
} TIMEOUT_PARAM;
static void timeout_doall_arg(SSL_SESSION *session, void *void_param) {
TIMEOUT_PARAM *param = reinterpret_cast<TIMEOUT_PARAM *>(void_param);
if (param->time == 0 || //
session->time + session->timeout < session->time || //
param->time > (session->time + session->timeout)) {
// TODO(davidben): This can probably just call |remove_session|.
(void)lh_SSL_SESSION_delete(param->cache, session);
SSL_SESSION_list_remove(param->ctx, session);
// TODO(https://crbug.com/boringssl/251): Callbacks should not be called
// under a lock.
if (param->ctx->remove_session_cb != NULL) {
param->ctx->remove_session_cb(param->ctx, session);
}
SSL_SESSION_free(session);
}
}
void SSL_CTX_flush_sessions(SSL_CTX *ctx, uint64_t time) {
TIMEOUT_PARAM tp;
tp.ctx = ctx;
tp.cache = ctx->sessions;
if (tp.cache == NULL) {
return;
}
tp.time = time;
MutexWriteLock lock(&ctx->lock);
lh_SSL_SESSION_doall_arg(tp.cache, timeout_doall_arg, &tp);
}
void SSL_CTX_sess_set_new_cb(SSL_CTX *ctx,
int (*cb)(SSL *ssl, SSL_SESSION *session)) {
ctx->new_session_cb = cb;
}
int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(SSL *ssl, SSL_SESSION *session) {
return ctx->new_session_cb;
}
void SSL_CTX_sess_set_remove_cb(SSL_CTX *ctx,
void (*cb)(SSL_CTX *ctx,
SSL_SESSION *session)) {
ctx->remove_session_cb = cb;
}
void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(SSL_CTX *ctx,
SSL_SESSION *session) {
return ctx->remove_session_cb;
}
void SSL_CTX_sess_set_get_cb(SSL_CTX *ctx,
SSL_SESSION *(*cb)(SSL *ssl, const uint8_t *id,
int id_len, int *out_copy)) {
ctx->get_session_cb = cb;
}
SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(SSL *ssl,
const uint8_t *id,
int id_len,
int *out_copy) {
return ctx->get_session_cb;
}
void SSL_CTX_set_info_callback(SSL_CTX *ctx, void (*cb)(const SSL *ssl,
int type, int value)) {
ctx->info_callback = cb;
}
void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl, int type,
int value) {
return ctx->info_callback;
}