BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, CRYPTO_MUTEX *lock,
const BIGNUM *mod, BN_CTX *bn_ctx) {
CRYPTO_MUTEX_lock_read(lock);
BN_MONT_CTX *ctx = *pmont;
CRYPTO_MUTEX_unlock(lock);
if (ctx) {
return ctx;
}
CRYPTO_MUTEX_lock_write(lock);
ctx = *pmont;
if (ctx) {
goto out;
}
ctx = BN_MONT_CTX_new();
if (ctx == NULL) {
goto out;
}
if (!BN_MONT_CTX_set(ctx, mod, bn_ctx)) {
BN_MONT_CTX_free(ctx);
ctx = NULL;
goto out;
}
*pmont = ctx;
out:
CRYPTO_MUTEX_unlock(lock);
return ctx;
}
int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c) {
int ret = 0;
SSL_SESSION *s;
/* 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(c);
/* if session c is in already in cache, we take back the increment later */
CRYPTO_MUTEX_lock_write(&ctx->lock);
if (!lh_SSL_SESSION_insert(ctx->sessions, &s, c)) {
CRYPTO_MUTEX_unlock(&ctx->lock);
return 0;
}
/* s != NULL iff we already had a session with the given PID. In this case, s
* == c should hold (then we did not really modify ctx->sessions), or we're
* in trouble. */
if (s != NULL && s != c) {
/* We *are* in trouble ... */
SSL_SESSION_list_remove(ctx, s);
SSL_SESSION_free(s);
/* ... 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) */
s = NULL;
}
/* Put at the head of the queue unless it is already in the cache */
if (s == NULL) {
SSL_SESSION_list_add(ctx, c);
}
if (s != NULL) {
/* existing cache entry -- decrement previously incremented reference count
* because it already takes into account the cache */
SSL_SESSION_free(s); /* s == c */
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;
}
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;
}
static int remove_session_lock(SSL_CTX *ctx, SSL_SESSION *c, int lock) {
SSL_SESSION *r;
int ret = 0;
if (c != NULL && c->session_id_length != 0) {
if (lock) {
CRYPTO_MUTEX_lock_write(&ctx->lock);
}
r = lh_SSL_SESSION_retrieve(ctx->sessions, c);
if (r == c) {
ret = 1;
r = lh_SSL_SESSION_delete(ctx->sessions, c);
SSL_SESSION_list_remove(ctx, c);
}
if (lock) {
CRYPTO_MUTEX_unlock(&ctx->lock);
}
if (ret) {
r->not_resumable = 1;
if (ctx->remove_session_cb != NULL) {
ctx->remove_session_cb(ctx, r);
}
SSL_SESSION_free(r);
}
}
return ret;
}
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(&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(&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(&ctx->lock);
return 1;
}
/* rsa_blinding_release marks the cached BN_BLINDING at the given index as free
* for other threads to use. */
static void rsa_blinding_release(RSA *rsa, BN_BLINDING *blinding,
unsigned blinding_index) {
if (blinding_index == MAX_BLINDINGS_PER_RSA) {
/* This blinding wasn't cached. */
BN_BLINDING_free(blinding);
return;
}
CRYPTO_MUTEX_lock_write(&rsa->lock);
rsa->blindings_inuse[blinding_index] = 0;
CRYPTO_MUTEX_unlock(&rsa->lock);
}
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);
}
/* 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);
}
/* TODO(davidben): This should probably move it to the front of the list. */
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, ©);
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;
}
/* rsa_blinding_get returns a BN_BLINDING to use with |rsa|. It does this by
* allocating one of the cached BN_BLINDING objects in |rsa->blindings|. If
* none are free, the cache will be extended by a extra element and the new
* BN_BLINDING is returned.
*
* On success, the index of the assigned BN_BLINDING is written to
* |*index_used| and must be passed to |rsa_blinding_release| when finished. */
static BN_BLINDING *rsa_blinding_get(RSA *rsa, unsigned *index_used,
BN_CTX *ctx) {
BN_BLINDING *ret = NULL;
BN_BLINDING **new_blindings;
uint8_t *new_blindings_inuse;
char overflow = 0;
CRYPTO_MUTEX_lock_write(&rsa->lock);
unsigned i;
for (i = 0; i < rsa->num_blindings; i++) {
if (rsa->blindings_inuse[i] == 0) {
rsa->blindings_inuse[i] = 1;
ret = rsa->blindings[i];
*index_used = i;
break;
}
}
if (ret != NULL) {
CRYPTO_MUTEX_unlock(&rsa->lock);
return ret;
}
overflow = rsa->num_blindings >= MAX_BLINDINGS_PER_RSA;
/* We didn't find a free BN_BLINDING to use so increase the length of
* the arrays by one and use the newly created element. */
CRYPTO_MUTEX_unlock(&rsa->lock);
ret = rsa_setup_blinding(rsa, ctx);
if (ret == NULL) {
return NULL;
}
if (overflow) {
/* We cannot add any more cached BN_BLINDINGs so we use |ret|
* and mark it for destruction in |rsa_blinding_release|. */
*index_used = MAX_BLINDINGS_PER_RSA;
return ret;
}
CRYPTO_MUTEX_lock_write(&rsa->lock);
new_blindings =
OPENSSL_malloc(sizeof(BN_BLINDING *) * (rsa->num_blindings + 1));
if (new_blindings == NULL) {
goto err1;
}
memcpy(new_blindings, rsa->blindings,
sizeof(BN_BLINDING *) * rsa->num_blindings);
new_blindings[rsa->num_blindings] = ret;
new_blindings_inuse = OPENSSL_malloc(rsa->num_blindings + 1);
if (new_blindings_inuse == NULL) {
goto err2;
}
memcpy(new_blindings_inuse, rsa->blindings_inuse, rsa->num_blindings);
new_blindings_inuse[rsa->num_blindings] = 1;
*index_used = rsa->num_blindings;
OPENSSL_free(rsa->blindings);
rsa->blindings = new_blindings;
OPENSSL_free(rsa->blindings_inuse);
rsa->blindings_inuse = new_blindings_inuse;
rsa->num_blindings++;
CRYPTO_MUTEX_unlock(&rsa->lock);
return ret;
err2:
OPENSSL_free(new_blindings);
err1:
CRYPTO_MUTEX_unlock(&rsa->lock);
BN_BLINDING_free(ret);
return NULL;
}
/* ssl_get_prev attempts to find an SSL_SESSION to be used to resume this
* connection. It is only called by servers.
*
* ctx: contains the early callback context, which is the result of a
* shallow parse of the ClientHello.
*
* Returns:
* -1: error
* 0: a session may have been found.
*
* Side effects:
* - If a session is found then s->session is pointed at it (after freeing an
* existing session if need be) and s->verify_result is set from the session.
* - Both for new and resumed sessions, s->tlsext_ticket_expected is set to 1
* if the server should issue a new session ticket (to 0 otherwise). */
int ssl_get_prev_session(SSL *s, const struct ssl_early_callback_ctx *ctx) {
/* This is used only by servers. */
SSL_SESSION *ret = NULL;
int fatal = 0;
int try_session_cache = 1;
int r;
if (ctx->session_id_len > SSL_MAX_SSL_SESSION_ID_LENGTH) {
goto err;
}
if (ctx->session_id_len == 0) {
try_session_cache = 0;
}
r = tls1_process_ticket(s, ctx, &ret); /* sets s->tlsext_ticket_expected */
switch (r) {
case -1: /* Error during processing */
fatal = 1;
goto err;
case 0: /* No ticket found */
case 1: /* Zero length ticket found */
break; /* Ok to carry on processing session id. */
case 2: /* Ticket found but not decrypted. */
case 3: /* Ticket decrypted, *ret has been set. */
try_session_cache = 0;
break;
default:
abort();
}
if (try_session_cache && ret == NULL &&
!(s->initial_ctx->session_cache_mode &
SSL_SESS_CACHE_NO_INTERNAL_LOOKUP)) {
SSL_SESSION data;
data.ssl_version = s->version;
data.session_id_length = ctx->session_id_len;
if (ctx->session_id_len == 0) {
return 0;
}
memcpy(data.session_id, ctx->session_id, ctx->session_id_len);
CRYPTO_MUTEX_lock_read(&s->initial_ctx->lock);
ret = lh_SSL_SESSION_retrieve(s->initial_ctx->sessions, &data);
if (ret != NULL) {
SSL_SESSION_up_ref(ret);
}
CRYPTO_MUTEX_unlock(&s->initial_ctx->lock);
}
if (try_session_cache && ret == NULL &&
s->initial_ctx->get_session_cb != NULL) {
int copy = 1;
ret = s->initial_ctx->get_session_cb(s, (uint8_t *)ctx->session_id,
ctx->session_id_len, ©);
if (ret != NULL) {
if (ret == SSL_magic_pending_session_ptr()) {
/* This is a magic value which indicates that the callback needs to
* unwind the stack and figure out the session asynchronously. */
return 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(ret);
}
/* Add the externally cached session to the internal cache as well if and
* only if we are supposed to. */
if (!(s->initial_ctx->session_cache_mode &
SSL_SESS_CACHE_NO_INTERNAL_STORE)) {
/* The following should not return 1, otherwise, things are very
* strange */
SSL_CTX_add_session(s->initial_ctx, ret);
}
}
}
if (ret == NULL) {
goto err;
}
/* Now ret is non-NULL and we own one of its reference counts. */
if (ret->sid_ctx_length != s->sid_ctx_length ||
memcmp(ret->sid_ctx, s->sid_ctx, ret->sid_ctx_length)) {
/* We have the session requested by the client, but we don't want to use it
* in this context. */
goto err; /* treat like cache miss */
}
if ((s->verify_mode & SSL_VERIFY_PEER) && s->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_get_prev_session,
SSL_R_SESSION_ID_CONTEXT_UNINITIALIZED);
fatal = 1;
goto err;
}
if (ret->timeout < (long)(time(NULL) - ret->time)) {
/* timeout */
if (try_session_cache) {
/* session was from the cache, so remove it */
SSL_CTX_remove_session(s->initial_ctx, ret);
}
goto err;
}
SSL_SESSION_free(s->session);
s->session = ret;
s->verify_result = s->session->verify_result;
return 1;
err:
if (ret != NULL) {
SSL_SESSION_free(ret);
if (!try_session_cache) {
/* The session was from a ticket, so we should
* issue a ticket for the new session */
s->tlsext_ticket_expected = 1;
}
}
if (fatal) {
return -1;
}
return 0;
}
