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/* Copyright (c) 2004-2018 Dovecot authors, see the included COPYING file */
#include "auth-common.h"
#include "str.h"
#include "strescape.h"
#include "restrict-process-size.h"
#include "auth-request-stats.h"
#include "auth-worker-server.h"
#include "password-scheme.h"
#include "passdb.h"
#include "passdb-cache.h"
#include "passdb-blocking.h"
struct auth_cache *passdb_cache = NULL;
static void
passdb_cache_log_hit(struct auth_request *request, const char *value)
{
const char *p;
if (!request->set->debug_passwords &&
*value != '\0' && *value != '\t') {
/* hide the password */
p = strchr(value, '\t');
value = t_strconcat(PASSWORD_HIDDEN_STR, p, NULL);
}
e_debug(authdb_event(request), "cache hit: %s", value);
}
static bool
passdb_cache_lookup(struct auth_request *request, const char *key,
bool use_expired, struct auth_cache_node **node_r,
const char **value_r, bool *neg_expired_r)
{
struct auth_stats *stats = auth_request_stats_get(request);
const char *value;
bool expired;
request->passdb_cache_result = AUTH_REQUEST_CACHE_MISS;
/* value = password \t ... */
value = auth_cache_lookup(passdb_cache, request, key, node_r,
&expired, neg_expired_r);
if (value == NULL || (expired && !use_expired)) {
stats->auth_cache_miss_count++;
e_debug(authdb_event(request),
value == NULL ? "cache miss" :
"cache expired");
return FALSE;
}
stats->auth_cache_hit_count++;
passdb_cache_log_hit(request, value);
request->passdb_cache_result = AUTH_REQUEST_CACHE_HIT;
*value_r = value;
return TRUE;
}
static bool
passdb_cache_verify_plain_callback(struct auth_worker_connection *conn ATTR_UNUSED,
const char *reply, void *context)
{
struct auth_request *request = context;
enum passdb_result result;
result = passdb_blocking_auth_worker_reply_parse(request, reply);
if (result != PASSDB_RESULT_OK)
auth_fields_rollback(request->fields.extra_fields);
auth_request_verify_plain_callback_finish(result, request);
auth_request_unref(&request);
return TRUE;
}
bool passdb_cache_verify_plain(struct auth_request *request, const char *key,
const char *password,
enum passdb_result *result_r, bool use_expired)
{
const char *value, *cached_pw, *scheme, *const *list;
struct auth_cache_node *node;
int ret;
bool neg_expired;
if (passdb_cache == NULL || key == NULL)
return FALSE;
if (!passdb_cache_lookup(request, key, use_expired,
&node, &value, &neg_expired))
return FALSE;
if (*value == '\0') {
/* negative cache entry */
auth_request_log_unknown_user(request, AUTH_SUBSYS_DB);
*result_r = PASSDB_RESULT_USER_UNKNOWN;
auth_request_verify_plain_callback_finish(*result_r, request);
return TRUE;
}
list = t_strsplit_tabescaped(value);
cached_pw = list[0];
if (*cached_pw == '\0') {
/* NULL password */
e_info(authdb_event(request),
"Cached NULL password access");
ret = 1;
} else if (request->set->cache_verify_password_with_worker) {
string_t *str;
str = t_str_new(128);
str_printfa(str, "PASSW\t%u\t", request->passdb->passdb->id);
str_append_tabescaped(str, password);
str_append_c(str, '\t');
str_append_tabescaped(str, cached_pw);
str_append_c(str, '\t');
auth_request_export(request, str);
e_debug(authdb_event(request), "cache: "
"validating password on worker");
auth_request_ref(request);
/* Save the extra fields already here, and take a snapshot.
If verification fails, roll back fields. */
auth_request_set_fields(request, list + 1, NULL);
auth_fields_snapshot(request->fields.extra_fields);
auth_worker_call(request->pool, request->fields.user, str_c(str),
passdb_cache_verify_plain_callback, request);
return TRUE;
} else {
scheme = password_get_scheme(&cached_pw);
i_assert(scheme != NULL);
ret = auth_request_password_verify_log(request, password, cached_pw,
scheme, AUTH_SUBSYS_DB,
!(node->last_success || neg_expired));
if (ret == 0 && (node->last_success || neg_expired)) {
/* a) the last authentication was successful. assume
that the password was changed and cache is expired.
b) negative TTL reached, use it for password
mismatches too. */
node->last_success = FALSE;
return FALSE;
}
}
node->last_success = ret > 0;
/* save the extra_fields only after we know we're using the
cached data */
auth_request_set_fields(request, list + 1, NULL);
*result_r = ret > 0 ? PASSDB_RESULT_OK :
PASSDB_RESULT_PASSWORD_MISMATCH;
auth_request_verify_plain_callback_finish(*result_r, request);
return TRUE;
}
bool passdb_cache_lookup_credentials(struct auth_request *request,
const char *key, const char **password_r,
const char **scheme_r,
enum passdb_result *result_r,
bool use_expired)
{
const char *value, *const *list;
struct auth_cache_node *node;
bool neg_expired;
if (passdb_cache == NULL)
return FALSE;
if (!passdb_cache_lookup(request, key, use_expired,
&node, &value, &neg_expired))
return FALSE;
if (*value == '\0') {
/* negative cache entry */
*result_r = PASSDB_RESULT_USER_UNKNOWN;
*password_r = NULL;
*scheme_r = NULL;
return TRUE;
}
list = t_strsplit_tabescaped(value);
auth_request_set_fields(request, list + 1, NULL);
*result_r = PASSDB_RESULT_OK;
*password_r = *list[0] == '\0' ? NULL : list[0];
*scheme_r = password_get_scheme(password_r);
i_assert(*scheme_r != NULL || *password_r == NULL);
return TRUE;
}
void passdb_cache_init(const struct auth_settings *set)
{
rlim_t limit;
if (set->cache_size == 0 || set->cache_ttl == 0)
return;
if (restrict_get_process_size(&limit) == 0 &&
set->cache_size > (uoff_t)limit) {
i_warning("auth_cache_size (%"PRIuUOFF_T"M) is higher than "
"process VSZ limit (%"PRIuUOFF_T"M)",
set->cache_size/1024/1024,
(uoff_t)(limit/1024/1024));
}
passdb_cache = auth_cache_new(set->cache_size, set->cache_ttl,
set->cache_negative_ttl);
}
void passdb_cache_deinit(void)
{
if (passdb_cache != NULL)
auth_cache_free(&passdb_cache);
}
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