src/auth/passdb-cache.c

	passdb-cache.c revision 89a126810703c666309310d0f3189e9834d70b5b
/* Copyright (c) 2004-2007 Dovecot authors, see the included COPYING file */

#include "common.h"
#include "password-scheme.h"
#include "passdb.h"
#include "passdb-cache.h"

#include <stdlib.h>

struct auth_cache *passdb_cache = NULL;

bool passdb_cache_verify_plain(struct auth_request *request, const char *key,
                   const char *password,
                   enum passdb_result *result_r, int use_expired)
{
    const char *value, *cached_pw, *scheme, *const *list;
    struct auth_cache_node *node;
    int ret;
    bool expired;

    if (passdb_cache == NULL || key == NULL)
        return FALSE;

    /* value = password \t ... */
    value = auth_cache_lookup(passdb_cache, request, key, &node, &expired);
    if (value == NULL || (expired && !use_expired)) {
        auth_request_log_debug(request, "cache",
                       value == NULL ? "miss" : "expired");
        return FALSE;
    }
    auth_request_log_debug(request, "cache", "hit");

    if (*value == '\0') {
        /* negative cache entry */
        auth_request_log_info(request, "cache", "User unknown");
        *result_r = PASSDB_RESULT_USER_UNKNOWN;
        return TRUE;
    }

    list = t_strsplit(value, "\t");

    cached_pw = list[0];
    if (*cached_pw == '\0') {
        /* NULL password */
        auth_request_log_info(request, "cache", "NULL password access");
        ret = 1;
    } else {
        scheme = password_get_scheme(&cached_pw);
        i_assert(scheme != NULL);

        ret = auth_request_password_verify(request, password, cached_pw,
                           scheme, "cache");

        if (ret == 0 && node->last_success) {
            /* the last authentication was successful. assume that
               the password was changed and cache is expired. */
            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;
    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 expired;

    if (passdb_cache == NULL)
        return FALSE;

    value = auth_cache_lookup(passdb_cache, request, key, &node, &expired);
    if (value == NULL || (expired && !use_expired)) {
        auth_request_log_debug(request, "cache",
                       value == NULL ? "miss" : "expired");
        return FALSE;
    }
    auth_request_log_debug(request, "cache", "hit");

    if (*value == '\0') {
        /* negative cache entry */
        *result_r = PASSDB_RESULT_USER_UNKNOWN;
        *password_r = NULL;
        *scheme_r = NULL;
        return TRUE;
    }

    list = t_strsplit(value, "\t");
    auth_request_set_fields(request, list + 1, NULL);

    *result_r = PASSDB_RESULT_OK;
    *password_r = list[0];
    *scheme_r = password_get_scheme(password_r);
    i_assert(*scheme_r != NULL || *password_r == '\0');

    if (*password_r == '\0') {
        *password_r = NULL;
        *result_r = PASSDB_RESULT_SCHEME_NOT_AVAILABLE;
    }
    return TRUE;
}

void passdb_cache_init(void)
{
    const char *env;
    size_t max_size;
    unsigned int cache_ttl, neg_cache_ttl;

    env = getenv("CACHE_SIZE");
    if (env == NULL)
        return;

    max_size = (size_t)strtoul(env, NULL, 10) * 1024;
    if (max_size == 0)
        return;

    env = getenv("CACHE_TTL");
    if (env == NULL)
        return;

    cache_ttl = (unsigned int)strtoul(env, NULL, 10);
    if (cache_ttl == 0)
        return;

    env = getenv("CACHE_NEGATIVE_TTL");
    neg_cache_ttl = env == NULL ? 0 : (unsigned int)strtoul(env, NULL, 10);
    passdb_cache = auth_cache_new(max_size, cache_ttl, neg_cache_ttl);
}

void passdb_cache_deinit(void)
{
    if (passdb_cache != NULL)
        auth_cache_free(&passdb_cache);
}