src/auth/auth-settings.c

/* Copyright (c) 2005-2018 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "array.h"
#include "hash-method.h"
#include "settings-parser.h"
#include "master-service-private.h"
#include "master-service-settings.h"
#include "service-settings.h"
#include "auth-settings.h"

#include <stddef.h>

static bool auth_settings_check(void *_set, pool_t pool, const char **error_r);
static bool auth_passdb_settings_check(void *_set, pool_t pool, const char **error_r);
static bool auth_userdb_settings_check(void *_set, pool_t pool, const char **error_r);

/* <settings checks> */
static struct file_listener_settings auth_unix_listeners_array[] = {
    { "login/login", 0666, "", "" },
    { "token-login/tokenlogin", 0666, "", "" },
    { "auth-login", 0600, "$default_internal_user", "" },
    { "auth-client", 0600, "$default_internal_user", "" },
    { "auth-userdb", 0666, "$default_internal_user", "" },
    { "auth-master", 0600, "", "" }
};
static struct file_listener_settings *auth_unix_listeners[] = {
    &auth_unix_listeners_array[0],
    &auth_unix_listeners_array[1],
    &auth_unix_listeners_array[2],
    &auth_unix_listeners_array[3],
    &auth_unix_listeners_array[4],
    &auth_unix_listeners_array[5]
};
static buffer_t auth_unix_listeners_buf = {
    auth_unix_listeners, sizeof(auth_unix_listeners), { NULL, }
};
/* </settings checks> */

struct service_settings auth_service_settings = {
    .name = "auth",
    .protocol = "",
    .type = "",
    .executable = "auth",
    .user = "$default_internal_user",
    .group = "",
    .privileged_group = "",
    .extra_groups = "",
    .chroot = "",

    .drop_priv_before_exec = FALSE,

    .process_min_avail = 0,
    .process_limit = 1,
    .client_limit = 0,
    .service_count = 0,
    .idle_kill = 0,
    .vsz_limit = (uoff_t)-1,

    .unix_listeners = { { &auth_unix_listeners_buf,
                  sizeof(auth_unix_listeners[0]) } },
    .fifo_listeners = ARRAY_INIT,
    .inet_listeners = ARRAY_INIT,

    .process_limit_1 = TRUE
};

/* <settings checks> */
static struct file_listener_settings auth_worker_unix_listeners_array[] = {
    { "auth-worker", 0600, "$default_internal_user", "" }
};
static struct file_listener_settings *auth_worker_unix_listeners[] = {
    &auth_worker_unix_listeners_array[0]
};
static buffer_t auth_worker_unix_listeners_buf = {
    auth_worker_unix_listeners, sizeof(auth_worker_unix_listeners), { NULL, }
};
/* </settings checks> */

struct service_settings auth_worker_service_settings = {
    .name = "auth-worker",
    .protocol = "",
    .type = "",
    .executable = "auth -w",
    .user = "",
    .group = "",
    .privileged_group = "",
    .extra_groups = "",
    .chroot = "",

    .drop_priv_before_exec = FALSE,

    .process_min_avail = 0,
    .process_limit = 0,
    .client_limit = 1,
    .service_count = 1,
    .idle_kill = 0,
    .vsz_limit = (uoff_t)-1,

    .unix_listeners = { { &auth_worker_unix_listeners_buf,
                  sizeof(auth_worker_unix_listeners[0]) } },
    .fifo_listeners = ARRAY_INIT,
    .inet_listeners = ARRAY_INIT
};

#undef DEF
#define DEF(type, name) \
    { type, #name, offsetof(struct auth_passdb_settings, name), NULL }

static const struct setting_define auth_passdb_setting_defines[] = {
    DEF(SET_STR, name),
    DEF(SET_STR, driver),
    DEF(SET_STR, args),
    DEF(SET_STR, default_fields),
    DEF(SET_STR, override_fields),
    DEF(SET_STR, mechanisms),
    DEF(SET_STR, username_filter),

    DEF(SET_ENUM, skip),
    DEF(SET_ENUM, result_success),
    DEF(SET_ENUM, result_failure),
    DEF(SET_ENUM, result_internalfail),

    DEF(SET_BOOL, deny),
    DEF(SET_BOOL, pass),
    DEF(SET_BOOL, master),
    DEF(SET_ENUM, auth_verbose),

    SETTING_DEFINE_LIST_END
};

static const struct auth_passdb_settings auth_passdb_default_settings = {
    .name = "",
    .driver = "",
    .args = "",
    .default_fields = "",
    .override_fields = "",
    .mechanisms = "",
    .username_filter = "",

    .skip = "never:authenticated:unauthenticated",
    .result_success = "return-ok:return:return-fail:continue:continue-ok:continue-fail",
    .result_failure = "continue:return:return-ok:return-fail:continue-ok:continue-fail",
    .result_internalfail = "continue:return:return-ok:return-fail:continue-ok:continue-fail",

    .deny = FALSE,
    .pass = FALSE,
    .master = FALSE,
    .auth_verbose = "default:yes:no"
};

const struct setting_parser_info auth_passdb_setting_parser_info = {
    .defines = auth_passdb_setting_defines,
    .defaults = &auth_passdb_default_settings,

    .type_offset = offsetof(struct auth_passdb_settings, name),
    .struct_size = sizeof(struct auth_passdb_settings),

    .parent_offset = (size_t)-1,
    .parent = &auth_setting_parser_info,

    .check_func = auth_passdb_settings_check
};

#undef DEF
#define DEF(type, name) \
    { type, #name, offsetof(struct auth_userdb_settings, name), NULL }

static const struct setting_define auth_userdb_setting_defines[] = {
    DEF(SET_STR, name),
    DEF(SET_STR, driver),
    DEF(SET_STR, args),
    DEF(SET_STR, default_fields),
    DEF(SET_STR, override_fields),

    DEF(SET_ENUM, skip),
    DEF(SET_ENUM, result_success),
    DEF(SET_ENUM, result_failure),
    DEF(SET_ENUM, result_internalfail),

    DEF(SET_ENUM, auth_verbose),

    SETTING_DEFINE_LIST_END
};

static const struct auth_userdb_settings auth_userdb_default_settings = {
    /* NOTE: when adding fields, update also auth.c:userdb_dummy_set */
    .name = "",
    .driver = "",
    .args = "",
    .default_fields = "",
    .override_fields = "",

    .skip = "never:found:notfound",
    .result_success = "return-ok:return:return-fail:continue:continue-ok:continue-fail",
    .result_failure = "continue:return:return-ok:return-fail:continue-ok:continue-fail",
    .result_internalfail = "continue:return:return-ok:return-fail:continue-ok:continue-fail",

    .auth_verbose = "default:yes:no"
};

const struct setting_parser_info auth_userdb_setting_parser_info = {
    .defines = auth_userdb_setting_defines,
    .defaults = &auth_userdb_default_settings,

    .type_offset = offsetof(struct auth_userdb_settings, name),
    .struct_size = sizeof(struct auth_userdb_settings),

    .parent_offset = (size_t)-1,
    .parent = &auth_setting_parser_info,

    .check_func = auth_userdb_settings_check
};

/* we're kind of kludging here to avoid "auth_" prefix in the struct fields */
#undef DEF
#undef DEF_NOPREFIX
#undef DEFLIST
#define DEF(type, name) \
    { type, "auth_"#name, offsetof(struct auth_settings, name), NULL }
#define DEF_NOPREFIX(type, name) \
    { type, #name, offsetof(struct auth_settings, name), NULL }
#define DEFLIST(field, name, defines) \
    { SET_DEFLIST, name, offsetof(struct auth_settings, field), defines }

static const struct setting_define auth_setting_defines[] = {
    DEF(SET_STR, mechanisms),
    DEF(SET_STR, realms),
    DEF(SET_STR, default_realm),
    DEF(SET_SIZE, cache_size),
    DEF(SET_TIME, cache_ttl),
    DEF(SET_TIME, cache_negative_ttl),
    DEF(SET_BOOL, cache_verify_password_with_worker),
    DEF(SET_STR, username_chars),
    DEF(SET_STR, username_translation),
    DEF(SET_STR, username_format),
    DEF(SET_STR, master_user_separator),
    DEF(SET_STR, anonymous_username),
    DEF(SET_STR, krb5_keytab),
    DEF(SET_STR, gssapi_hostname),
    DEF(SET_STR, winbind_helper_path),
    DEF(SET_STR, proxy_self),
    DEF(SET_TIME, failure_delay),

    DEF(SET_STR, policy_server_url),
    DEF(SET_STR, policy_server_api_header),
    DEF(SET_UINT, policy_server_timeout_msecs),
    DEF(SET_STR, policy_hash_mech),
    DEF(SET_STR, policy_hash_nonce),
    DEF(SET_STR, policy_request_attributes),
    DEF(SET_BOOL, policy_reject_on_fail),
    DEF(SET_BOOL, policy_check_before_auth),
    DEF(SET_BOOL, policy_check_after_auth),
    DEF(SET_BOOL, policy_report_after_auth),
    DEF(SET_UINT, policy_hash_truncate),

    DEF(SET_BOOL, stats),
    DEF(SET_BOOL, verbose),
    DEF(SET_BOOL, debug),
    DEF(SET_BOOL, debug_passwords),
    DEF(SET_STR, verbose_passwords),
    DEF(SET_BOOL, ssl_require_client_cert),
    DEF(SET_BOOL, ssl_username_from_cert),
    DEF(SET_BOOL, use_winbind),

    DEF(SET_UINT, worker_max_count),

    DEFLIST(passdbs, "passdb", &auth_passdb_setting_parser_info),
    DEFLIST(userdbs, "userdb", &auth_userdb_setting_parser_info),

    DEF_NOPREFIX(SET_STR, base_dir),
    DEF_NOPREFIX(SET_BOOL, verbose_proctitle),
    DEF_NOPREFIX(SET_UINT, first_valid_uid),
    DEF_NOPREFIX(SET_UINT, last_valid_uid),
    DEF_NOPREFIX(SET_UINT, first_valid_gid),
    DEF_NOPREFIX(SET_UINT, last_valid_gid),

    DEF_NOPREFIX(SET_STR, ssl_client_ca_dir),
    DEF_NOPREFIX(SET_STR, ssl_client_ca_file),

    SETTING_DEFINE_LIST_END
};

static const struct auth_settings auth_default_settings = {
    .mechanisms = "plain",
    .realms = "",
    .default_realm = "",
    .cache_size = 0,
    .cache_ttl = 60*60,
    .cache_negative_ttl = 60*60,
    .cache_verify_password_with_worker = FALSE,
    .username_chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@",
    .username_translation = "",
    .username_format = "%Lu",
    .master_user_separator = "",
    .anonymous_username = "anonymous",
    .krb5_keytab = "",
    .gssapi_hostname = "",
    .winbind_helper_path = "/usr/bin/ntlm_auth",
    .proxy_self = "",
    .failure_delay = 2,

    .policy_server_url = "",
    .policy_server_api_header = "",
    .policy_server_timeout_msecs = 2000,
    .policy_hash_mech = "sha256",
    .policy_hash_nonce = "",
    .policy_request_attributes = "login=%{requested_username} pwhash=%{hashed_password} remote=%{rip} device_id=%{client_id} protocol=%s",
    .policy_reject_on_fail = FALSE,
    .policy_check_before_auth = TRUE,
    .policy_check_after_auth = TRUE,
    .policy_report_after_auth = TRUE,
    .policy_hash_truncate = 12,

    .stats = FALSE,
    .verbose = FALSE,
    .debug = FALSE,
    .debug_passwords = FALSE,
    .verbose_passwords = "no",
    .ssl_require_client_cert = FALSE,
    .ssl_username_from_cert = FALSE,
    .ssl_client_ca_dir = "",
    .ssl_client_ca_file = "",

    .use_winbind = FALSE,

    .worker_max_count = 30,

    .passdbs = ARRAY_INIT,
    .userdbs = ARRAY_INIT,

    .base_dir = PKG_RUNDIR,
    .verbose_proctitle = FALSE,
    .first_valid_uid = 500,
    .last_valid_uid = 0,
    .first_valid_gid = 1,
    .last_valid_gid = 0,
};

const struct setting_parser_info auth_setting_parser_info = {
    .module_name = "auth",
    .defines = auth_setting_defines,
    .defaults = &auth_default_settings,

    .type_offset = (size_t)-1,
    .struct_size = sizeof(struct auth_settings),

    .parent_offset = (size_t)-1,

    .check_func = auth_settings_check
};

/* <settings checks> */
static bool
auth_settings_set_self_ips(struct auth_settings *set, pool_t pool,
               const char **error_r)
{
    const char *const *tmp;
    ARRAY(struct ip_addr) ips_array;
    struct ip_addr *ips;
    unsigned int ips_count;
    int ret;

    if (*set->proxy_self == '\0') {
        set->proxy_self_ips = p_new(pool, struct ip_addr, 1);
        return TRUE;
    }

    p_array_init(&ips_array, pool, 4);
    tmp = t_strsplit_spaces(set->proxy_self, " ");
    for (; *tmp != NULL; tmp++) {
        ret = net_gethostbyname(*tmp, &ips, &ips_count);
        if (ret != 0) {
            *error_r = t_strdup_printf("auth_proxy_self_ips: "
                "gethostbyname(%s) failed: %s",
                *tmp, net_gethosterror(ret));
        }
        array_append(&ips_array, ips, ips_count);
    }
    array_append_zero(&ips_array);
    set->proxy_self_ips = array_idx(&ips_array, 0);
    return TRUE;
}

static bool
auth_verify_verbose_password(struct auth_settings *set,
                 const char **error_r)
{
    const char *p, *value = set->verbose_passwords;
    unsigned int num;

    p = strchr(value, ':');
    if (p != NULL) {
        if (str_to_uint(p+1, &num) < 0 || num == 0) {
            *error_r = t_strdup_printf("auth_verbose_passwords: "
                "Invalid truncation number: '%s'", p+1);
            return FALSE;
        }
        value = t_strdup_until(value, p);
    }
    if (strcmp(value, "no") == 0)
        return TRUE;
    else if (strcmp(value, "plain") == 0)
        return TRUE;
    else if (strcmp(value, "sha1") == 0)
        return TRUE;
    else if (strcmp(value, "yes") == 0) {
        /* just use it as alias for "plain" */
        set->verbose_passwords = "plain";
        return TRUE;
    } else {
        *error_r = "auth_verbose_passwords: Invalid value";
        return FALSE;
    }
}

static bool auth_settings_check(void *_set, pool_t pool,
                const char **error_r)
{
    struct auth_settings *set = _set;
    const char *p;

    if (set->debug_passwords)
        set->debug = TRUE;
    if (set->debug)
        set->verbose = TRUE;

    if (set->worker_max_count == 0) {
        *error_r = "auth_worker_max_count must be above zero";
        return FALSE;
    }

    if (set->cache_size > 0 && set->cache_size < 1024) {
        /* probably a configuration error.
           older versions used megabyte numbers */
        *error_r = t_strdup_printf("auth_cache_size value is too small "
                       "(%"PRIuUOFF_T" bytes)",
                       set->cache_size);
        return FALSE;
    }

    if (!auth_verify_verbose_password(set, error_r))
        return FALSE;

    if (*set->username_chars == '\0') {
        /* all chars are allowed */
        memset(set->username_chars_map, 1,
               sizeof(set->username_chars_map));
    } else {
        for (p = set->username_chars; *p != '\0'; p++)
            set->username_chars_map[(int)(uint8_t)*p] = 1;
    }

    if (*set->username_translation != '\0') {
        p = set->username_translation;
        for (; *p != '\0' && p[1] != '\0'; p += 2)
            set->username_translation_map[(int)(uint8_t)*p] = p[1];
    }
    set->realms_arr =
        (const char *const *)p_strsplit_spaces(pool, set->realms, " ");

    if (*set->policy_server_url != '\0') {
        if (*set->policy_hash_nonce == '\0') {

            *error_r = "auth_policy_hash_nonce must be set when policy server is used";
            return FALSE;
        }
        const struct hash_method *digest = hash_method_lookup(set->policy_hash_mech);
        if (digest == NULL) {
            *error_r = "invalid auth_policy_hash_mech given";
            return FALSE;
        }
        if (set->policy_hash_truncate > 0 && set->policy_hash_truncate >= digest->digest_size*8) {
            *error_r = t_strdup_printf("policy_hash_truncate is not smaller than digest size (%u >= %u)",
                set->policy_hash_truncate,
                digest->digest_size*8);
            return FALSE;
        }
    }

    if (!auth_settings_set_self_ips(set, pool, error_r))
        return FALSE;
    return TRUE;
}

static bool
auth_passdb_settings_check(void *_set, pool_t pool ATTR_UNUSED,
               const char **error_r)
{
    struct auth_passdb_settings *set = _set;

    if (set->driver == NULL || *set->driver == '\0') {
        *error_r = "passdb is missing driver";
        return FALSE;
    }
    if (set->pass && strcmp(set->result_success, "return-ok") != 0) {
        *error_r = "Obsolete pass=yes setting mixed with non-default result_success";
        return FALSE;
    }
    return TRUE;
}

static bool
auth_userdb_settings_check(void *_set, pool_t pool ATTR_UNUSED,
               const char **error_r)
{
    struct auth_userdb_settings *set = _set;

    if (set->driver == NULL || *set->driver == '\0') {
        *error_r = "userdb is missing driver";
        return FALSE;
    }
    return TRUE;
}
/* </settings checks> */

struct auth_settings *global_auth_settings;

struct auth_settings *
auth_settings_read(const char *service, pool_t pool,
           struct master_service_settings_output *output_r)
{
    static const struct setting_parser_info *set_roots[] = {
        &auth_setting_parser_info,
        NULL
    };
    struct master_service_settings_input input;
    struct setting_parser_context *set_parser;
    const char *error;
    void **sets;

    i_zero(&input);
    input.roots = set_roots;
    input.module = "auth";
    input.service = service;
    if (master_service_settings_read(master_service, &input,
                     output_r, &error) < 0)
        i_fatal("Error reading configuration: %s", error);

    pool_ref(pool);
    set_parser = settings_parser_dup(master_service->set_parser, pool);
    if (!settings_parser_check(set_parser, pool, &error))
        i_unreached();

    sets = master_service_settings_parser_get_others(master_service,
                             set_parser);
    settings_parser_deinit(&set_parser);
    return sets[0];
}