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5a79ff5efd
boringssl/ssl/ssl_session.cc
David Benjamin 5a79ff5efd Clarify some comments. 
Further testing suggests the behavior is slightly different than I
originally thought.

Change-Id: I3df6b3425dbb551e374159566ca969347d72a306
Reviewed-on: https://boringssl-review.googlesource.com/20284
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-09-14 21:15:23 +00:00

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/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* ====================================================================
* Copyright (c) 1998-2006 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
/* ====================================================================
* Copyright 2005 Nokia. All rights reserved.
*
* The portions of the attached software ("Contribution") is developed by
* Nokia Corporation and is licensed pursuant to the OpenSSL open source
* license.
*
* The Contribution, originally written by Mika Kousa and Pasi Eronen of
* Nokia Corporation, consists of the "PSK" (Pre-Shared Key) ciphersuites
* support (see RFC 4279) to OpenSSL.
*
* No patent licenses or other rights except those expressly stated in
* the OpenSSL open source license shall be deemed granted or received
* expressly, by implication, estoppel, or otherwise.
*
* No assurances are provided by Nokia that the Contribution does not
* infringe the patent or other intellectual property rights of any third
* party or that the license provides you with all the necessary rights
* to make use of the Contribution.
*
* THE SOFTWARE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. IN
* ADDITION TO THE DISCLAIMERS INCLUDED IN THE LICENSE, NOKIA
* SPECIFICALLY DISCLAIMS ANY LIABILITY FOR CLAIMS BROUGHT BY YOU OR ANY
* OTHER ENTITY BASED ON INFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS OR
* OTHERWISE. */
#include <openssl/ssl.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <utility>
#include <openssl/err.h>
#include <openssl/lhash.h>
#include <openssl/mem.h>
#include <openssl/rand.h>
#include "internal.h"
#include "../crypto/internal.h"
namespace bssl {
// 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);
static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *session, int lock);
UniquePtr<SSL_SESSION> ssl_session_new(const SSL_X509_METHOD *x509_method) {
UniquePtr<SSL_SESSION> session(
(SSL_SESSION *)OPENSSL_malloc(sizeof(SSL_SESSION)));
if (!session) {
OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
return 0;
}
OPENSSL_memset(session.get(), 0, sizeof(SSL_SESSION));
session->x509_method = x509_method;
session->verify_result = X509_V_ERR_INVALID_CALL;
session->references = 1;
session->timeout = SSL_DEFAULT_SESSION_TIMEOUT;
session->auth_timeout = SSL_DEFAULT_SESSION_TIMEOUT;
session->time = time(NULL);
CRYPTO_new_ex_data(&session->ex_data);
return session;
}
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->sid_ctx_length = session->sid_ctx_length;
OPENSSL_memcpy(new_session->sid_ctx, session->sid_ctx, session->sid_ctx_length);
// Copy the key material.
new_session->master_key_length = session->master_key_length;
OPENSSL_memcpy(new_session->master_key, session->master_key,
session->master_key_length);
new_session->cipher = session->cipher;
// Copy authentication state.
if (session->psk_identity != NULL) {
new_session->psk_identity = BUF_strdup(session->psk_identity);
if (new_session->psk_identity == NULL) {
return nullptr;
}
}
if (session->certs != NULL) {
new_session->certs = sk_CRYPTO_BUFFER_new_null();
if (new_session->certs == NULL) {
return nullptr;
}
for (size_t i = 0; i < sk_CRYPTO_BUFFER_num(session->certs); i++) {
CRYPTO_BUFFER *buffer = sk_CRYPTO_BUFFER_value(session->certs, i);
if (!sk_CRYPTO_BUFFER_push(new_session->certs, buffer)) {
return nullptr;
}
CRYPTO_BUFFER_up_ref(buffer);
}
}
if (!session->x509_method->session_dup(new_session.get(), session)) {
return nullptr;
}
new_session->verify_result = session->verify_result;
if (session->ocsp_response != NULL) {
new_session->ocsp_response = session->ocsp_response;
CRYPTO_BUFFER_up_ref(new_session->ocsp_response);
}
if (session->signed_cert_timestamp_list != NULL) {
new_session->signed_cert_timestamp_list =
session->signed_cert_timestamp_list;
CRYPTO_BUFFER_up_ref(new_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_length = session->session_id_length;
OPENSSL_memcpy(new_session->session_id, session->session_id,
session->session_id_length);
new_session->group_id = session->group_id;
OPENSSL_memcpy(new_session->original_handshake_hash,
session->original_handshake_hash,
session->original_handshake_hash_len);
new_session->original_handshake_hash_len =
session->original_handshake_hash_len;
new_session->tlsext_tick_lifetime_hint = session->tlsext_tick_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;
if (session->early_alpn != NULL) {
new_session->early_alpn =
(uint8_t *)BUF_memdup(session->early_alpn, session->early_alpn_len);
if (new_session->early_alpn == NULL) {
return nullptr;
}
}
new_session->early_alpn_len = session->early_alpn_len;
}
// Copy the ticket.
if (dup_flags & SSL_SESSION_INCLUDE_TICKET) {
if (session->tlsext_tick != NULL) {
new_session->tlsext_tick =
(uint8_t *)BUF_memdup(session->tlsext_tick, session->tlsext_ticklen);
if (new_session->tlsext_tick == NULL) {
return nullptr;
}
}
new_session->tlsext_ticklen = session->tlsext_ticklen;
}
// The new_session does not get a copy of the ex_data.
new_session->not_resumable = 1;
return new_session;
}
void ssl_session_rebase_time(SSL *ssl, SSL_SESSION *session) {
struct OPENSSL_timeval now;
ssl_get_current_time(ssl, &now);
// 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);
}
int ssl_get_new_session(SSL_HANDSHAKE *hs, int is_server) {
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 0;
}
UniquePtr<SSL_SESSION> session = ssl_session_new(ssl->ctx->x509_method);
if (session == NULL) {
return 0;
}
session->is_server = is_server;
session->ssl_version = ssl->version;
// Fill in the time from the |SSL_CTX|'s clock.
struct OPENSSL_timeval now;
ssl_get_current_time(ssl, &now);
session->time = now.tv_sec;
uint16_t version = ssl3_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 (is_server) {
if (hs->ticket_expected || version >= TLS1_3_VERSION) {
// Don't set session IDs for sessions resumed with tickets. This will keep
// them out of the session cache.
session->session_id_length = 0;
} else {
session->session_id_length = SSL3_SSL_SESSION_ID_LENGTH;
if (!RAND_bytes(session->session_id, session->session_id_length)) {
return 0;
}
}
} else {
session->session_id_length = 0;
}
if (ssl->cert->sid_ctx_length > sizeof(session->sid_ctx)) {
OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
return 0;
}
OPENSSL_memcpy(session->sid_ctx, ssl->cert->sid_ctx,
ssl->cert->sid_ctx_length);
session->sid_ctx_length = ssl->cert->sid_ctx_length;
// The session is marked not resumable until it is completely filled in.
session->not_resumable = 1;
session->verify_result = X509_V_ERR_INVALID_CALL;
hs->new_session = std::move(session);
ssl_set_session(ssl, NULL);
return 1;
}
int ssl_ctx_rotate_ticket_encryption_key(SSL_CTX *ctx) {
OPENSSL_timeval now;
ssl_ctx_get_current_time(ctx, &now);
{
// 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->tlsext_ticket_key_current &&
(ctx->tlsext_ticket_key_current->next_rotation_tv_sec == 0 ||
ctx->tlsext_ticket_key_current->next_rotation_tv_sec > now.tv_sec) &&
(!ctx->tlsext_ticket_key_prev ||
ctx->tlsext_ticket_key_prev->next_rotation_tv_sec > now.tv_sec)) {
return 1;
}
}
MutexWriteLock lock(&ctx->lock);
if (!ctx->tlsext_ticket_key_current ||
(ctx->tlsext_ticket_key_current->next_rotation_tv_sec != 0 &&
ctx->tlsext_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<struct tlsext_ticket_key>();
if (!new_key) {
return 0;
}
OPENSSL_memset(new_key.get(), 0, sizeof(struct tlsext_ticket_key));
if (ctx->tlsext_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 droppped below.
ctx->tlsext_ticket_key_current->next_rotation_tv_sec +=
SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL;
OPENSSL_free(ctx->tlsext_ticket_key_prev);
ctx->tlsext_ticket_key_prev = ctx->tlsext_ticket_key_current;
}
ctx->tlsext_ticket_key_current = new_key.release();
RAND_bytes(ctx->tlsext_ticket_key_current->name, 16);
RAND_bytes(ctx->tlsext_ticket_key_current->hmac_key, 16);
RAND_bytes(ctx->tlsext_ticket_key_current->aes_key, 16);
ctx->tlsext_ticket_key_current->next_rotation_tv_sec =
now.tv_sec + SSL_DEFAULT_TICKET_KEY_ROTATION_INTERVAL;
}
// Drop an expired prev key.
if (ctx->tlsext_ticket_key_prev &&
ctx->tlsext_ticket_key_prev->next_rotation_tv_sec <= now.tv_sec) {
OPENSSL_free(ctx->tlsext_ticket_key_prev);
ctx->tlsext_ticket_key_prev = nullptr;
}
return 1;
}
static int ssl_encrypt_ticket_with_cipher_ctx(SSL *ssl, CBB *out,
const uint8_t *session_buf,
size_t session_len) {
ScopedEVP_CIPHER_CTX ctx;
ScopedHMAC_CTX hctx;
// If the session is too long, emit a dummy value rather than abort the
// connection.
static const size_t kMaxTicketOverhead =
16 + EVP_MAX_IV_LENGTH + EVP_MAX_BLOCK_LENGTH + EVP_MAX_MD_SIZE;
if (session_len > 0xffff - kMaxTicketOverhead) {
static const char kTicketPlaceholder[] = "TICKET TOO LARGE";
return CBB_add_bytes(out, (const uint8_t *)kTicketPlaceholder,
strlen(kTicketPlaceholder));
}
// Initialize HMAC and cipher contexts. If callback present it does all the
// work otherwise use generated values from parent ctx.
SSL_CTX *tctx = ssl->session_ctx;
uint8_t iv[EVP_MAX_IV_LENGTH];
uint8_t key_name[16];
if (tctx->tlsext_ticket_key_cb != NULL) {
if (tctx->tlsext_ticket_key_cb(ssl, key_name, iv, ctx.get(), hctx.get(),
1 /* encrypt */) < 0) {
return 0;
}
} 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->tlsext_ticket_key_current->aes_key, iv) ||
!HMAC_Init_ex(hctx.get(), tctx->tlsext_ticket_key_current->hmac_key, 16,
tlsext_tick_md(), NULL)) {
return 0;
}
OPENSSL_memcpy(key_name, tctx->tlsext_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 *ssl, CBB *out,
const uint8_t *session_buf,
size_t session_len) {
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;
}
int ssl_encrypt_ticket(SSL *ssl, CBB *out, const SSL_SESSION *session) {
// Serialize the SSL_SESSION to be encoded into the ticket.
uint8_t *session_buf = NULL;
size_t session_len;
if (!SSL_SESSION_to_bytes_for_ticket(session, &session_buf, &session_len)) {
return -1;
}
int ret = 0;
if (ssl->session_ctx->ticket_aead_method) {
ret = ssl_encrypt_ticket_with_method(ssl, out, session_buf, session_len);
} else {
ret =
ssl_encrypt_ticket_with_cipher_ctx(ssl, out, session_buf, session_len);
}
OPENSSL_free(session_buf);
return ret;
}
int ssl_session_is_context_valid(const SSL *ssl, const SSL_SESSION *session) {
if (session == NULL) {
return 0;
}
return session->sid_ctx_length == ssl->cert->sid_ctx_length &&
OPENSSL_memcmp(session->sid_ctx, ssl->cert->sid_ctx,
ssl->cert->sid_ctx_length) == 0;
}
int ssl_session_is_time_valid(const SSL *ssl, const SSL_SESSION *session) {
if (session == NULL) {
return 0;
}
struct OPENSSL_timeval now;
ssl_get_current_time(ssl, &now);
// Reject tickets from the future to avoid underflow.
if (now.tv_sec < session->time) {
return 0;
}
return session->timeout > now.tv_sec - session->time;
}
int ssl_session_is_resumable(const SSL_HANDSHAKE *hs,
const SSL_SESSION *session) {
const SSL *const ssl = hs->ssl;
return ssl_session_is_context_valid(ssl, 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->version == session->ssl_version &&
// Only resume if the session's cipher matches the negotiated one.
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) == 0 &&
!session->peer_sha256_valid) ||
session->peer_sha256_valid ==
ssl->retain_only_sha256_of_client_certs);
}
// 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 *ssl, UniquePtr<SSL_SESSION> *out_session, const uint8_t *session_id,
size_t session_id_len) {
out_session->reset();
if (session_id_len == 0 || session_id_len > 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)) {
SSL_SESSION data;
data.ssl_version = ssl->version;
data.session_id_length = session_id_len;
OPENSSL_memcpy(data.session_id, session_id, session_id_len);
CRYPTO_MUTEX_lock_read(&ssl->session_ctx->lock);
session.reset(lh_SSL_SESSION_retrieve(ssl->session_ctx->sessions, &data));
if (session) {
// |lh_SSL_SESSION_retrieve| returns a non-owning pointer.
SSL_SESSION_up_ref(session.get());
}
// TODO(davidben): This should probably move it to the front of the list.
CRYPTO_MUTEX_unlock_read(&ssl->session_ctx->lock);
}
// Fall back to the external cache, if it exists.
if (!session && ssl->session_ctx->get_session_cb != NULL) {
int copy = 1;
session.reset(ssl->session_ctx->get_session_cb(ssl, (uint8_t *)session_id,
session_id_len, &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, 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, session.get());
session.reset();
}
*out_session = std::move(session);
return ssl_hs_ok;
}
bool ssl_is_probably_java(const SSL_CLIENT_HELLO *client_hello) {
CBS extension, groups;
if (SSL_is_dtls(client_hello->ssl) ||
!ssl_client_hello_get_extension(client_hello, &extension,
TLSEXT_TYPE_supported_groups) ||
!CBS_get_u16_length_prefixed(&extension, &groups) ||
CBS_len(&extension) != 0) {
return false;
}
// Original Java curve list.
static const uint8_t kCurveList1[] = {
0x00, 0x17, 0x00, 0x01, 0x00, 0x03, 0x00, 0x13, 0x00, 0x15,
0x00, 0x06, 0x00, 0x07, 0x00, 0x09, 0x00, 0x0a, 0x00, 0x18,
0x00, 0x0b, 0x00, 0x0c, 0x00, 0x19, 0x00, 0x0d, 0x00, 0x0e,
0x00, 0x0f, 0x00, 0x10, 0x00, 0x11, 0x00, 0x02, 0x00, 0x12,
0x00, 0x04, 0x00, 0x05, 0x00, 0x14, 0x00, 0x08, 0x00, 0x16};
// Newer Java curve list.
static const uint8_t kCurveList2[] = {
0x00, 0x17, 0x00, 0x18, 0x00, 0x19, 0x00, 0x09, 0x00, 0x0a,
0x00, 0x0b, 0x00, 0x0c, 0x00, 0x0d, 0x00, 0x0e, 0x00, 0x16};
// IcedTea curve list.
static const uint8_t kCurveList3[] = {0x00, 0x17, 0x00, 0x18, 0x00, 0x19};
auto groups_span = MakeConstSpan(CBS_data(&groups), CBS_len(&groups));
if (groups_span != kCurveList1 && groups_span != kCurveList2 &&
groups_span != kCurveList3) {
return false;
}
// Java has a very distinctive curve list, but IcedTea patches it to a more
// standard [P-256, P-384, P-521]. Additionally check the extension
// order. This may still flag other clients, but false positives only mean a
// loss of resumption. Any client new enough to support one of X25519,
// extended master secret, session tickets, or TLS 1.3 will be unaffected.
//
// Java sends different extensions depending on configuration and version, but
// those which are present are always in the same order. Check if the
// extensions are an ordered subset of |kJavaExtensions|.
static const uint16_t kJavaExtensions[] = {
TLSEXT_TYPE_supported_groups,
TLSEXT_TYPE_ec_point_formats,
TLSEXT_TYPE_signature_algorithms,
TLSEXT_TYPE_server_name,
17 /* status_request_v2 */,
TLSEXT_TYPE_status_request,
TLSEXT_TYPE_application_layer_protocol_negotiation,
TLSEXT_TYPE_renegotiate,
};
CBS extensions;
CBS_init(&extensions, client_hello->extensions, client_hello->extensions_len);
for (uint16_t expected : kJavaExtensions) {
CBS extensions_copy = extensions, body;
uint16_t type;
// Peek at the next extension.
if (CBS_get_u16(&extensions_copy, &type) &&
CBS_get_u16_length_prefixed(&extensions_copy, &body) &&
type == expected) {
extensions = extensions_copy;
}
}
return CBS_len(&extensions) == 0;
}
enum ssl_hs_wait_t ssl_get_prev_session(SSL *ssl,
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(ssl->server);
// If tickets are disabled, always behave as if no tickets are present.
const uint8_t *ticket = NULL;
size_t ticket_len = 0;
const bool tickets_supported =
!(SSL_get_options(ssl) & SSL_OP_NO_TICKET) &&
ssl->version > SSL3_VERSION &&
SSL_early_callback_ctx_extension_get(
client_hello, TLSEXT_TYPE_session_ticket, &ticket, &ticket_len);
if (ssl_is_probably_java(client_hello)) {
// The Java client implementation of the 3SHAKE mitigation incorrectly
// rejects initial handshakes when all of the following are true:
//
// 1. The ClientHello offered a session.
// 2. The session was successfully resumed previously.
// 3. The server declines the session.
// 4. The server sends a certificate with a different (see below) SAN list
// than in the previous session.
//
// (Note the 3SHAKE mitigation is to reject certificates changes on
// renegotiation, while Java's logic applies to initial handshakes as well.)
//
// The end result is long-lived Java clients break on certificate rotations
// where the SAN list changes too much. Older versions of Java break if the
// first DNS name of the two certificates is different. Newer ones will
// break if there is no intersection. The new logic mostly mitigates this,
// but this can still cause problems if switching to or from wildcards.
//
// Thus, fingerprint Java clients and decline all offered sessions. This
// avoids (2) while still introducing new sessions to clear any existing
// problematic sessions.
*out_session = nullptr;
*out_tickets_supported = tickets_supported;
*out_renew_ticket = false;
return ssl_hs_ok;
}
UniquePtr<SSL_SESSION> session;
bool renew_ticket = false;
if (tickets_supported && ticket_len > 0) {
switch (ssl_process_ticket(ssl, &session, &renew_ticket, ticket, ticket_len,
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(
ssl, &session, 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 int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *session, int lock) {
int ret = 0;
if (session != NULL && session->session_id_length != 0) {
if (lock) {
CRYPTO_MUTEX_lock_write(&ctx->lock);
}
SSL_SESSION *found_session = lh_SSL_SESSION_retrieve(ctx->sessions,
session);
if (found_session == session) {
ret = 1;
found_session = lh_SSL_SESSION_delete(ctx->sessions, session);
SSL_SESSION_list_remove(ctx, session);
}
if (lock) {
CRYPTO_MUTEX_unlock_write(&ctx->lock);
}
if (ret) {
if (ctx->remove_session_cb != NULL) {
ctx->remove_session_cb(ctx, found_session);
}
SSL_SESSION_free(found_session);
}
}
return ret;
}
void ssl_set_session(SSL *ssl, SSL_SESSION *session) {
if (ssl->session == session) {
return;
}
SSL_SESSION_free(ssl->session);
ssl->session = session;
if (session != NULL) {
SSL_SESSION_up_ref(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;
}
}
} // namespace bssl
using namespace bssl;
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) {
CRYPTO_refcount_inc(&session->references);
return 1;
}
void SSL_SESSION_free(SSL_SESSION *session) {
if (session == NULL ||
!CRYPTO_refcount_dec_and_test_zero(&session->references)) {
return;
}
CRYPTO_free_ex_data(&g_ex_data_class, session, &session->ex_data);
OPENSSL_cleanse(session->master_key, sizeof(session->master_key));
OPENSSL_cleanse(session->session_id, sizeof(session->session_id));
sk_CRYPTO_BUFFER_pop_free(session->certs, CRYPTO_BUFFER_free);
session->x509_method->session_clear(session);
OPENSSL_free(session->tlsext_tick);
CRYPTO_BUFFER_free(session->signed_cert_timestamp_list);
CRYPTO_BUFFER_free(session->ocsp_response);
OPENSSL_free(session->psk_identity);
OPENSSL_free(session->early_alpn);
OPENSSL_cleanse(session, sizeof(*session));
OPENSSL_free(session);
}
const uint8_t *SSL_SESSION_get_id(const SSL_SESSION *session,
unsigned *out_len) {
if (out_len != NULL) {
*out_len = session->session_id_length;
}
return session->session_id;
}
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;
}
size_t SSL_SESSION_get_master_key(const SSL_SESSION *session, uint8_t *out,
size_t max_out) {
// TODO(davidben): Fix master_key_length's type and remove these casts.
if (max_out == 0) {
return (size_t)session->master_key_length;
}
if (max_out > (size_t)session->master_key_length) {
max_out = (size_t)session->master_key_length;
}
OPENSSL_memcpy(out, session->master_key, 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;
}
int SSL_SESSION_set1_id_context(SSL_SESSION *session, const uint8_t *sid_ctx,
size_t sid_ctx_len) {
if (sid_ctx_len > sizeof(session->sid_ctx)) {
OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG);
return 0;
}
static_assert(sizeof(session->sid_ctx) < 256, "sid_ctx_len does not fit");
session->sid_ctx_length = (uint8_t)sid_ctx_len;
OPENSSL_memcpy(session->sid_ctx, sid_ctx, sid_ctx_len);
return 1;
}
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 handshake completes we return the established session. Otherwise
// we return the intermediate session, either |session| (for resumption) or
// |new_session| if doing a full handshake.
if (!SSL_in_init(ssl)) {
return ssl->s3->established_session;
}
SSL_HANDSHAKE *hs = ssl->s3->hs;
if (hs->early_session) {
return hs->early_session.get();
}
if (hs->new_session) {
return hs->new_session.get();
}
return ssl->session;
}
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) {
int index;
if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp,
free_func)) {
return -1;
}
return index;
}
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) {
// Although |session| is inserted into two structures (a doubly-linked list
// and the hash table), |ctx| only takes one reference.
SSL_SESSION_up_ref(session);
SSL_SESSION *old_session;
CRYPTO_MUTEX_lock_write(&ctx->lock);
if (!lh_SSL_SESSION_insert(ctx->sessions, &old_session, session)) {
CRYPTO_MUTEX_unlock_write(&ctx->lock);
SSL_SESSION_free(session);
return 0;
}
if (old_session != NULL) {
if (old_session == session) {
// |session| was already in the cache.
CRYPTO_MUTEX_unlock_write(&ctx->lock);
SSL_SESSION_free(old_session);
return 0;
}
// There was a session ID collision. |old_session| must be removed from
// the linked list and released.
SSL_SESSION_list_remove(ctx, old_session);
SSL_SESSION_free(old_session);
}
SSL_SESSION_list_add(ctx, session);
// Enforce any cache size limits.
if (SSL_CTX_sess_get_cache_size(ctx) > 0) {
while (SSL_CTX_sess_number(ctx) > SSL_CTX_sess_get_cache_size(ctx)) {
if (!remove_session_lock(ctx, ctx->session_cache_tail, 0)) {
break;
}
}
}
CRYPTO_MUTEX_unlock_write(&ctx->lock);
return 1;
}
int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session) {
return remove_session_lock(ctx, session, 1);
}
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)) {
// The reason we don't call SSL_CTX_remove_session() is to
// save on locking overhead
(void) lh_SSL_SESSION_delete(param->cache, session);
SSL_SESSION_list_remove(param->ctx, session);
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;
CRYPTO_MUTEX_lock_write(&ctx->lock);
lh_SSL_SESSION_doall_arg(tp.cache, timeout_doall_arg, &tp);
CRYPTO_MUTEX_unlock_write(&ctx->lock);
}
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,
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, 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;
}
void SSL_CTX_set_channel_id_cb(SSL_CTX *ctx,
void (*cb)(SSL *ssl, EVP_PKEY **pkey)) {
ctx->channel_id_cb = cb;
}
void (*SSL_CTX_get_channel_id_cb(SSL_CTX *ctx))(SSL *ssl, EVP_PKEY **pkey) {
return ctx->channel_id_cb;
}
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