am b8494591: Revert "Revert "external/boringssl: sync with upstream.""

* commit 'b8494591d1b1a143f3b192d845c238bbf3bc629d':
  Revert "Revert "external/boringssl: sync with upstream.""

1 files changed, 852 insertions, 0 deletions

diff --git a/src/ssl/ssl_session.c b/src/ssl/ssl_session.c
new file mode 100644
index 0000000..345aca2
--- /dev/null
+++ b/src/ssl/ssl_session.c
@@ -0,0 +1,852 @@
+/* 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 <stdio.h>
+#include <string.h>
+
+#include <openssl/err.h>
+#include <openssl/lhash.h>
+#include <openssl/mem.h>
+#include <openssl/rand.h>
+
+#include "internal.h"
+#include "../crypto/internal.h"
+
+
+/* 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);
+
+SSL_SESSION *SSL_SESSION_new(void) {
+  SSL_SESSION *session = (SSL_SESSION *)OPENSSL_malloc(sizeof(SSL_SESSION));
+  if (session == NULL) {
+    OPENSSL_PUT_ERROR(SSL, ERR_R_MALLOC_FAILURE);
+    return 0;
+  }
+  memset(session, 0, sizeof(SSL_SESSION));
+
+  session->verify_result = 1; /* avoid 0 (= X509_V_OK) just in case */
+  session->references = 1;
+  session->timeout = SSL_DEFAULT_SESSION_TIMEOUT;
+  session->time = (unsigned long)time(NULL);
+  CRYPTO_new_ex_data(&g_ex_data_class, session, &session->ex_data);
+  return session;
+}
+
+SSL_SESSION *SSL_SESSION_up_ref(SSL_SESSION *session) {
+  if (session != NULL) {
+    CRYPTO_refcount_inc(&session->references);
+  }
+  return session;
+}
+
+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));
+  X509_free(session->peer);
+  sk_X509_pop_free(session->cert_chain, X509_free);
+  OPENSSL_free(session->tlsext_hostname);
+  OPENSSL_free(session->tlsext_tick);
+  OPENSSL_free(session->tlsext_signed_cert_timestamp_list);
+  OPENSSL_free(session->ocsp_response);
+  OPENSSL_free(session->psk_identity);
+  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;
+}
+
+long SSL_SESSION_get_timeout(const SSL_SESSION *session) {
+  return session->timeout;
+}
+
+long SSL_SESSION_get_time(const SSL_SESSION *session) {
+  return session->time;
+}
+
+uint32_t SSL_SESSION_get_key_exchange_info(const SSL_SESSION *session) {
+  return session->key_exchange_info;
+}
+
+X509 *SSL_SESSION_get0_peer(const SSL_SESSION *session) {
+  return session->peer;
+}
+
+long SSL_SESSION_set_time(SSL_SESSION *session, long time) {
+  if (session == NULL) {
+    return 0;
+  }
+
+  session->time = time;
+  return time;
+}
+
+long SSL_SESSION_set_timeout(SSL_SESSION *session, long timeout) {
+  if (session == NULL) {
+    return 0;
+  }
+
+  session->timeout = timeout;
+  return 1;
+}
+
+int SSL_SESSION_set1_id_context(SSL_SESSION *session, const uint8_t *sid_ctx,
+                                unsigned sid_ctx_len) {
+  if (sid_ctx_len > SSL_MAX_SID_CTX_LENGTH) {
+    OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_SESSION_ID_CONTEXT_TOO_LONG);
+    return 0;
+  }
+
+  session->sid_ctx_length = sid_ctx_len;
+  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)
+{
+  /* aka SSL_get0_session; gets 0 objects, just returns a copy of the pointer */
+  return ssl->session;
+}
+
+SSL_SESSION *SSL_get1_session(SSL *ssl) {
+  /* variant of SSL_get_session: caller really gets something */
+  return SSL_SESSION_up_ref(ssl->session);
+}
+
+int SSL_SESSION_get_ex_new_index(long argl, void *argp, CRYPTO_EX_new *new_func,
+                                 CRYPTO_EX_dup *dup_func,
+                                 CRYPTO_EX_free *free_func) {
+  int index;
+  if (!CRYPTO_get_ex_new_index(&g_ex_data_class, &index, argl, argp, new_func,
+                               dup_func, 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);
+}
+
+/* Even with SSLv2, we have 16 bytes (128 bits) of session ID space.
+ * SSLv3/TLSv1 has 32 bytes (256 bits). As such, filling the ID with random
+ * gunk repeatedly until we have no conflict is going to complete in one
+ * iteration pretty much "most" of the time (btw: understatement). So, if it
+ * takes us 10 iterations and we still can't avoid a conflict - well that's a
+ * reasonable point to call it quits. Either the RAND code is broken or someone
+ * is trying to open roughly very close to 2^128 (or 2^256) SSL sessions to our
+ * server. How you might store that many sessions is perhaps a more interesting
+ * question ... */
+static int def_generate_session_id(const SSL *ssl, uint8_t *id,
+                                   unsigned *id_len) {
+  static const unsigned kMaxAttempts = 10;
+  unsigned retry = 0;
+  do {
+    if (!RAND_bytes(id, *id_len)) {
+      return 0;
+    }
+  } while (SSL_has_matching_session_id(ssl, id, *id_len) &&
+           (++retry < kMaxAttempts));
+
+  if (retry < kMaxAttempts) {
+    return 1;
+  }
+
+  /* else - woops a session_id match */
+  /* XXX We should also check the external cache -- but the probability of a
+   * collision is negligible, and we could not prevent the concurrent creation
+   * of sessions with identical IDs since we currently don't have means to
+   * atomically check whether a session ID already exists and make a
+   * reservation for it if it does not (this problem applies to the internal
+   * cache as well). */
+  return 0;
+}
+
+int ssl_get_new_session(SSL *s, int session) {
+  /* This gets used by clients and servers. */
+
+  unsigned int tmp;
+  SSL_SESSION *ss = NULL;
+  GEN_SESSION_CB cb = def_generate_session_id;
+
+  if (s->mode & SSL_MODE_NO_SESSION_CREATION) {
+    OPENSSL_PUT_ERROR(SSL, SSL_R_SESSION_MAY_NOT_BE_CREATED);
+    return 0;
+  }
+
+  ss = SSL_SESSION_new();
+  if (ss == NULL) {
+    return 0;
+  }
+
+  /* If the context has a default timeout, use it over the default. */
+  if (s->initial_ctx->session_timeout != 0) {
+    ss->timeout = s->initial_ctx->session_timeout;
+  }
+
+  SSL_SESSION_free(s->session);
+  s->session = NULL;
+
+  if (session) {
+    if (s->version == SSL3_VERSION || s->version == TLS1_VERSION ||
+        s->version == TLS1_1_VERSION || s->version == TLS1_2_VERSION ||
+        s->version == DTLS1_VERSION || s->version == DTLS1_2_VERSION) {
+      ss->ssl_version = s->version;
+      ss->session_id_length = SSL3_SSL_SESSION_ID_LENGTH;
+    } else {
+      OPENSSL_PUT_ERROR(SSL, SSL_R_UNSUPPORTED_SSL_VERSION);
+      SSL_SESSION_free(ss);
+      return 0;
+    }
+
+    /* If RFC4507 ticket use empty session ID */
+    if (s->tlsext_ticket_expected) {
+      ss->session_id_length = 0;
+      goto sess_id_done;
+    }
+
+    /* Choose which callback will set the session ID */
+    if (s->generate_session_id) {
+      cb = s->generate_session_id;
+    } else if (s->initial_ctx->generate_session_id) {
+      cb = s->initial_ctx->generate_session_id;
+    }
+
+    /* Choose a session ID */
+    tmp = ss->session_id_length;
+    if (!cb(s, ss->session_id, &tmp)) {
+      /* The callback failed */
+      OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_SESSION_ID_CALLBACK_FAILED);
+      SSL_SESSION_free(ss);
+      return 0;
+    }
+
+    /* Don't allow the callback to set the session length to zero. nor set it
+     * higher than it was. */
+    if (!tmp || tmp > ss->session_id_length) {
+      /* The callback set an illegal length */
+      OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_SESSION_ID_HAS_BAD_LENGTH);
+      SSL_SESSION_free(ss);
+      return 0;
+    }
+
+    ss->session_id_length = tmp;
+    /* Finally, check for a conflict */
+    if (SSL_has_matching_session_id(s, ss->session_id, ss->session_id_length)) {
+      OPENSSL_PUT_ERROR(SSL, SSL_R_SSL_SESSION_ID_CONFLICT);
+      SSL_SESSION_free(ss);
+      return 0;
+    }
+
+  sess_id_done:
+    if (s->tlsext_hostname) {
+      ss->tlsext_hostname = BUF_strdup(s->tlsext_hostname);
+      if (ss->tlsext_hostname == NULL) {
+        OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
+        SSL_SESSION_free(ss);
+        return 0;
+      }
+    }
+  } else {
+    ss->session_id_length = 0;
+  }
+
+  if (s->sid_ctx_length > sizeof(ss->sid_ctx)) {
+    OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
+    SSL_SESSION_free(ss);
+    return 0;
+  }
+
+  memcpy(ss->sid_ctx, s->sid_ctx, s->sid_ctx_length);
+  ss->sid_ctx_length = s->sid_ctx_length;
+  s->session = ss;
+  ss->ssl_version = s->version;
+  ss->verify_result = X509_V_OK;
+
+  return 1;
+}
+
+/* ssl_lookup_session looks up |session_id| in the session cache and sets
+ * |*out_session| to an |SSL_SESSION| object if found. The caller takes
+ * ownership of the result. */
+static enum ssl_session_result_t ssl_lookup_session(
+    SSL *ssl, SSL_SESSION **out_session, const uint8_t *session_id,
+    size_t session_id_len) {
+  *out_session = NULL;
+
+  if (session_id_len == 0 || session_id_len > SSL_MAX_SSL_SESSION_ID_LENGTH) {
+    return ssl_session_success;
+  }
+
+  SSL_SESSION *session;
+  /* Try the internal cache, if it exists. */
+  if (!(ssl->initial_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;
+    memcpy(data.session_id, session_id, session_id_len);
+
+    CRYPTO_MUTEX_lock_read(&ssl->initial_ctx->lock);
+    session = lh_SSL_SESSION_retrieve(ssl->initial_ctx->sessions, &data);
+    if (session != NULL) {
+      SSL_SESSION_up_ref(session);
+    }
+    CRYPTO_MUTEX_unlock(&ssl->initial_ctx->lock);
+
+    if (session != NULL) {
+      *out_session = session;
+      return ssl_session_success;
+    }
+  }
+
+  /* Fall back to the external cache, if it exists. */
+  if (ssl->initial_ctx->get_session_cb == NULL) {
+    return ssl_session_success;
+  }
+  int copy = 1;
+  session = ssl->initial_ctx->get_session_cb(ssl, (uint8_t *)session_id,
+                                             session_id_len, &copy);
+  if (session == NULL) {
+    return ssl_session_success;
+  }
+  if (session == SSL_magic_pending_session_ptr()) {
+    return ssl_session_retry;
+  }
+
+  /* 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);
+  }
+
+  /* Add the externally cached session to the internal cache if necessary. */
+  if (!(ssl->initial_ctx->session_cache_mode &
+        SSL_SESS_CACHE_NO_INTERNAL_STORE)) {
+    SSL_CTX_add_session(ssl->initial_ctx, session);
+  }
+
+  *out_session = session;
+  return ssl_session_success;
+}
+
+enum ssl_session_result_t ssl_get_prev_session(
+    SSL *ssl, SSL_SESSION **out_session, int *out_send_ticket,
+    const struct ssl_early_callback_ctx *ctx) {
+  /* This is used only by servers. */
+  assert(ssl->server);
+  SSL_SESSION *session = NULL;
+  int send_ticket = 0;
+
+  /* If tickets are disabled, always behave as if no tickets are present. */
+  const uint8_t *ticket = NULL;
+  size_t ticket_len = 0;
+  const int tickets_supported =
+      !(SSL_get_options(ssl) & SSL_OP_NO_TICKET) &&
+      (ssl->version > SSL3_VERSION || ctx->extensions != NULL) &&
+      SSL_early_callback_ctx_extension_get(ctx, TLSEXT_TYPE_session_ticket,
+                                           &ticket, &ticket_len);
+  if (tickets_supported) {
+    if (!tls_process_ticket(ssl, &session, &send_ticket, ticket, ticket_len,
+                            ctx->session_id, ctx->session_id_len)) {
+      return ssl_session_error;
+    }
+  } else {
+    /* The client does not support session tickets, so the session ID should be
+     * used instead. */
+    enum ssl_session_result_t lookup_ret = ssl_lookup_session(
+        ssl, &session, ctx->session_id, ctx->session_id_len);
+    if (lookup_ret != ssl_session_success) {
+      return lookup_ret;
+    }
+  }
+
+  if (session == NULL ||
+      session->sid_ctx_length != ssl->sid_ctx_length ||
+      memcmp(session->sid_ctx, ssl->sid_ctx, ssl->sid_ctx_length) != 0) {
+    goto no_session;
+  }
+
+  if ((ssl->verify_mode & SSL_VERIFY_PEER) && ssl->sid_ctx_length == 0) {
+    /* We can't be sure if this session is being used out of context, which is
+     * especially important for SSL_VERIFY_PEER. The application should have
+     * used SSL[_CTX]_set_session_id_context.
+     *
+     * For this error case, we generate an error instead of treating the event
+     * like a cache miss (otherwise it would be easy for applications to
+     * effectively disable the session cache by accident without anyone
+     * noticing). */
+    OPENSSL_PUT_ERROR(SSL, SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
+    goto fatal_error;
+  }
+
+  if (session->timeout < (long)(time(NULL) - session->time)) {
+    if (!tickets_supported) {
+      /* The session was from the cache, so remove it. */
+      SSL_CTX_remove_session(ssl->initial_ctx, session);
+    }
+    goto no_session;
+  }
+
+  *out_session = session;
+  *out_send_ticket = send_ticket;
+  return ssl_session_success;
+
+fatal_error:
+  SSL_SESSION_free(session);
+  return ssl_session_error;
+
+no_session:
+  *out_session = NULL;
+  *out_send_ticket = tickets_supported;
+  SSL_SESSION_free(session);
+  return ssl_session_success;
+}
+
+int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *session) {
+  int ret = 0;
+  SSL_SESSION *old_session;
+
+  /* Add just 1 reference count for the |SSL_CTX|'s session cache even though it
+   * has two ways of access: each session is in a doubly linked list and an
+   * lhash. */
+  SSL_SESSION_up_ref(session);
+  /* If |session| is in already in cache, we take back the increment later. */
+
+  CRYPTO_MUTEX_lock_write(&ctx->lock);
+  if (!lh_SSL_SESSION_insert(ctx->sessions, &old_session, session)) {
+    CRYPTO_MUTEX_unlock(&ctx->lock);
+    SSL_SESSION_free(session);
+    return 0;
+  }
+
+  /* |old_session| != NULL iff we already had a session with the given session
+   * ID. In this case, |old_session| == |session| should hold (then we did not
+   * really modify |ctx->sessions|), or we're in trouble. */
+  if (old_session != NULL && old_session != session) {
+    /* We *are* in trouble ... */
+    SSL_SESSION_list_remove(ctx, old_session);
+    SSL_SESSION_free(old_session);
+    /* ... so pretend the other session did not exist in cache (we cannot
+     * handle two |SSL_SESSION| structures with identical session ID in the same
+     * cache, which could happen e.g. when two threads concurrently obtain the
+     * same session from an external cache). */
+    old_session = NULL;
+  }
+
+  /* Put at the head of the queue unless it is already in the cache. */
+  if (old_session == NULL) {
+    SSL_SESSION_list_add(ctx, session);
+  }
+
+  if (old_session != NULL) {
+    /* Existing cache entry -- decrement previously incremented reference count
+     * because it already takes into account the cache. */
+    SSL_SESSION_free(old_session); /* |old_session| == |session| */
+    ret = 0;
+  } else {
+    /* New cache entry -- remove old ones if cache has become too large. */
+    ret = 1;
+
+    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(&ctx->lock);
+  return ret;
+}
+
+int SSL_CTX_remove_session(SSL_CTX *ctx, SSL_SESSION *session) {
+  return remove_session_lock(ctx, session, 1);
+}
+
+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(&ctx->lock);
+    }
+
+    if (ret) {
+      found_session->not_resumable = 1;
+      if (ctx->remove_session_cb != NULL) {
+        ctx->remove_session_cb(ctx, found_session);
+      }
+      SSL_SESSION_free(found_session);
+    }
+  }
+
+  return ret;
+}
+
+int SSL_set_session(SSL *ssl, SSL_SESSION *session) {
+  if (ssl->session == session) {
+    return 1;
+  }
+
+  SSL_SESSION_free(ssl->session);
+  ssl->session = session;
+  if (session != NULL) {
+    SSL_SESSION_up_ref(session);
+    ssl->verify_result = session->verify_result;
+  }
+
+  return 1;
+}
+
+long SSL_CTX_set_timeout(SSL_CTX *ctx, long timeout) {
+  if (ctx == NULL) {
+    return 0;
+  }
+
+  long old_timeout = ctx->session_timeout;
+  ctx->session_timeout = timeout;
+  return old_timeout;
+}
+
+long SSL_CTX_get_timeout(const SSL_CTX *ctx) {
+  if (ctx == NULL) {
+    return 0;
+  }
+
+  return ctx->session_timeout;
+}
+
+typedef struct timeout_param_st {
+  SSL_CTX *ctx;
+  long time;
+  LHASH_OF(SSL_SESSION) *cache;
+} TIMEOUT_PARAM;
+
+static void timeout_doall_arg(SSL_SESSION *session, void *void_param) {
+  TIMEOUT_PARAM *param = void_param;
+
+  if (param->time == 0 ||
+      param->time > (session->time + session->timeout)) {
+    /* 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);
+    session->not_resumable = 1;
+    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, long 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(&ctx->lock);
+}
+
+int ssl_clear_bad_session(SSL *s) {
+  if (s->session != NULL && !(s->shutdown & SSL_SENT_SHUTDOWN) &&
+      !SSL_in_init(s)) {
+    SSL_CTX_remove_session(s->ctx, s->session);
+    return 1;
+  }
+
+  return 0;
+}
+
+/* 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;
+  }
+}
+
+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 val)) {
+  ctx->info_callback = cb;
+}
+
+void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))(const SSL *ssl, int type,
+                                                int val) {
+  return ctx->info_callback;
+}
+
+void SSL_CTX_set_client_cert_cb(SSL_CTX *ctx, int (*cb)(SSL *ssl, X509 **x509,
+                                                        EVP_PKEY **pkey)) {
+  ctx->client_cert_cb = cb;
+}
+
+int (*SSL_CTX_get_client_cert_cb(SSL_CTX *ctx))(SSL *ssl, X509 **x509,
+                                                EVP_PKEY **pkey) {
+  return ctx->client_cert_cb;
+}
+
+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;
+}