res_stir_shaken.c File Reference

#include "asterisk.h"
#include "asterisk/app.h"
#include "asterisk/cli.h"
#include "asterisk/conversions.h"
#include "asterisk/module.h"
#include "asterisk/global_datastores.h"
#include "asterisk/pbx.h"
#include "res_stir_shaken/stir_shaken.h"

Include dependency graph for res_stir_shaken.c:

Go to the source code of this file.

Data Structures
struct	stir_datastore

Macros
#define	_TRACE_PREFIX_   "rss",__LINE__, ""
#define	TN_AUTH_LIST_LONG   "TNAuthorizationList"
#define	TN_AUTH_LIST_OID   "1.3.6.1.5.5.7.1.26"
#define	TN_AUTH_LIST_SHORT   "TNAuthList"

Functions
static void	__reg_module (void)
static void	__unreg_module (void)
struct ast_module *	AST_MODULE_SELF_SYM (void)
int	ast_stir_shaken_add_result_to_channel (struct ast_stir_shaken_vs_ctx *ctx)
	Add a STIR/SHAKEN verification result to a channel.
static int	check_for_old_config (void)
static int	func_read (struct ast_channel *chan, const char *function, char *data, char *buf, size_t len)
	Retrieves STIR/SHAKEN verification information for the channel via dialplan. Examples:
int	get_tn_auth_nid (void)
	Retrieves the OpenSSL NID for the TN Auth list extension.
static int	load_module (void)
static int	reload_module (void)
static void	stir_datastore_destroy_cb (void *data)
	The callback to destroy a stir_shaken_datastore.
static void	stir_datastore_free (struct stir_datastore *datastore)
	Frees a stir_shaken_datastore structure.
static int	unload_module (void)

Variables
static struct ast_module_info	__mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER , .description = "STIR/SHAKEN Module for Asterisk" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .reload = reload_module, .load_pri = AST_MODPRI_CHANNEL_DEPEND - 1, .requires = "res_curl", }
static const struct ast_module_info *	ast_module_info = &__mod_info
static const struct ast_datastore_info	stir_shaken_datastore_info
static struct ast_custom_function	stir_shaken_function
static int	tn_auth_list_nid

Macro Definition Documentation

_TRACE_PREFIX_

#define _TRACE_PREFIX_   "rss",__LINE__, ""

Definition at line 26 of file res_stir_shaken.c.

TN_AUTH_LIST_LONG

#define TN_AUTH_LIST_LONG   "TNAuthorizationList"

Definition at line 300 of file res_stir_shaken.c.

TN_AUTH_LIST_OID

#define TN_AUTH_LIST_OID   "1.3.6.1.5.5.7.1.26"

Definition at line 298 of file res_stir_shaken.c.

TN_AUTH_LIST_SHORT

#define TN_AUTH_LIST_SHORT   "TNAuthList"

Definition at line 299 of file res_stir_shaken.c.

Function Documentation

__reg_module()

static void __reg_module ( void  )

static

Definition at line 390 of file res_stir_shaken.c.

__unreg_module()

static void __unreg_module ( void  )

static

Definition at line 390 of file res_stir_shaken.c.

AST_MODULE_SELF_SYM()

struct ast_module * AST_MODULE_SELF_SYM

(

void

)

Definition at line 390 of file res_stir_shaken.c.

ast_stir_shaken_add_result_to_channel()

int ast_stir_shaken_add_result_to_channel

(

struct ast_stir_shaken_vs_ctx *

ctx

)

Add a STIR/SHAKEN verification result to a channel.

Parameters

ctx	VS context

Return values

-1	on failure
0	on success

Definition at line 89 of file res_stir_shaken.c.

{
    struct stir_datastore *stir_datastore;
    struct ast_datastore *chan_datastore;
    const char *chan_name;
 
    if (!ctx->chan) {
        ast_log(LOG_ERROR, "Channel is required to add STIR/SHAKEN verification\n");
        return -1;
    }
 
    chan_name = ast_channel_name(ctx->chan);
 
    if (!ctx->identity_hdr) {
        ast_log(LOG_ERROR, "No identity to add STIR/SHAKEN verification to channel "
            "%s\n", chan_name);
        return -1;
    }
 
    if (!ctx->attestation) {
        ast_log(LOG_ERROR, "Attestation cannot be NULL to add STIR/SHAKEN verification to "
            "channel %s\n", chan_name);
        return -1;
    }
 
    stir_datastore = ast_calloc(1, sizeof(*stir_datastore));
    if (!stir_datastore) {
        ast_log(LOG_ERROR, "Failed to allocate space for STIR/SHAKEN datastore for "
            "channel %s\n", chan_name);
        return -1;
    }
 
    stir_datastore->identity = ast_strdup(ctx->identity_hdr);
    if (!stir_datastore->identity) {
        ast_log(LOG_ERROR, "Failed to allocate space for STIR/SHAKEN datastore "
            "identity for channel %s\n", chan_name);
        stir_datastore_free(stir_datastore);
        return -1;
    }
 
    stir_datastore->attestation = ast_strdup(ctx->attestation);
    if (!stir_datastore->attestation) {
        ast_log(LOG_ERROR, "Failed to allocate space for STIR/SHAKEN datastore "
            "attestation for channel %s\n", chan_name);
        stir_datastore_free(stir_datastore);
        return -1;
    }
 
    stir_datastore->verify_result = ctx->failure_reason;
 
    chan_datastore = ast_datastore_alloc(&stir_shaken_datastore_info, NULL);
    if (!chan_datastore) {
        ast_log(LOG_ERROR, "Failed to allocate space for datastore for channel "
            "%s\n", chan_name);
        stir_datastore_free(stir_datastore);
        return -1;
    }
 
    chan_datastore->data = stir_datastore;
 
    ast_channel_lock(ctx->chan);
    ast_channel_datastore_add(ctx->chan, chan_datastore);
    ast_channel_unlock(ctx->chan);
 
    return 0;
}

References ast_calloc, ast_channel_datastore_add(), ast_channel_lock, ast_channel_name(), ast_channel_unlock, ast_datastore_alloc, ast_log, ast_strdup, stir_datastore::attestation, ast_stir_shaken_vs_ctx::attestation, ast_stir_shaken_vs_ctx::chan, ast_datastore::data, ast_stir_shaken_vs_ctx::failure_reason, stir_datastore::identity, ast_stir_shaken_vs_ctx::identity_hdr, LOG_ERROR, NULL, stir_datastore_free(), stir_shaken_datastore_info, and stir_datastore::verify_result.

Referenced by process_failure(), and stir_shaken_incoming_request().

check_for_old_config()

static int check_for_old_config ( void  )

static

Definition at line 302 of file res_stir_shaken.c.

{
    const char *error_msg = "There appears to be a 'stir_shaken.conf' file"
    " with old configuration options in it.  Please see the new config"
    " file format in the configs/samples/stir_shaken.conf.sample file"
    " in the source tree at https://github.com/asterisk/asterisk/raw/master/configs/samples/stir_shaken.conf.sample"
    " or visit https://docs.asterisk.org/Deployment/STIR-SHAKEN for more information.";
    RAII_VAR(struct ast_config *, cfg, NULL, ast_config_destroy);
    struct ast_flags config_flags = { 0 };
    char *cat = NULL;
 
    cfg = ast_config_load("stir_shaken.conf", config_flags);
    if (cfg == CONFIG_STATUS_FILEMISSING) {
        /*
         * They may be loading from realtime so the fact that there's
         * no stir-shaken.conf file isn't an issue for this purpose.
         */
        return AST_MODULE_LOAD_SUCCESS;
    } else if (cfg == CONFIG_STATUS_FILEINVALID) {
        cfg = NULL;
        ast_log(LOG_ERROR, "The stir_shaken.conf file is invalid\n");
        return AST_MODULE_LOAD_DECLINE;
    } else if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
        /* This can never happen but is included for completeness */
        cfg = NULL;
        return AST_MODULE_LOAD_SUCCESS;
    }
 
    while ((cat = ast_category_browse(cfg, cat))) {
        const char *val;
        if (strcasecmp(cat, "general") == 0) {
            ast_log(LOG_ERROR, "%s\n", error_msg);
            return AST_MODULE_LOAD_DECLINE;
        }
        val = ast_variable_retrieve(cfg, cat, "type");
        if (val && (strcasecmp(val, "store") == 0 ||
            strcasecmp(val, "certificate") == 0)) {
            ast_log(LOG_ERROR, "%s\n", error_msg);
            return AST_MODULE_LOAD_DECLINE;
        }
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}

References ast_category_browse(), ast_config_destroy(), ast_config_load, ast_log, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, ast_variable_retrieve(), CONFIG_STATUS_FILEINVALID, CONFIG_STATUS_FILEMISSING, CONFIG_STATUS_FILEUNCHANGED, LOG_ERROR, NULL, and RAII_VAR.

Referenced by load_module().

func_read()

static int func_read ( struct ast_channel *  chan, const char *  function, char *  data, char *  buf, size_t  len  )

static

Retrieves STIR/SHAKEN verification information for the channel via dialplan. Examples:

STIR_SHAKEN(count) STIR_SHAKEN(0, identity) STIR_SHAKEN(1, attestation) STIR_SHAKEN(27, verify_result)

Return values

-1	on failure
0	on success

Definition at line 169 of file res_stir_shaken.c.

{
    struct stir_datastore *stir_datastore;
    struct ast_datastore *chan_datastore;
    char *parse;
    char *first;
    char *second;
    unsigned int target_index, current_index = 0;
    AST_DECLARE_APP_ARGS(args,
        AST_APP_ARG(first_param);
        AST_APP_ARG(second_param);
    );
 
    if (ast_strlen_zero(data)) {
        ast_log(LOG_WARNING, "%s requires at least one argument\n", function);
        return -1;
    }
 
    if (!chan) {
        ast_log(LOG_ERROR, "No channel for %s function\n", function);
        return -1;
    }
 
    parse = ast_strdupa(data);
 
    AST_STANDARD_APP_ARGS(args, parse);
 
    first = ast_strip(args.first_param);
    if (ast_strlen_zero(first)) {
        ast_log(LOG_ERROR, "An argument must be passed to %s\n", function);
        return -1;
    }
 
    second = ast_strip(args.second_param);
 
    /* Check if we are only looking for the number of STIR/SHAKEN verification results */
    if (!strcasecmp(first, "count")) {
        size_t count = 0;
 
        if (!ast_strlen_zero(second)) {
            ast_log(LOG_ERROR, "%s only takes 1 paramater for 'count'\n", function);
            return -1;
        }
 
        ast_channel_lock(chan);
        AST_LIST_TRAVERSE(ast_channel_datastores(chan), chan_datastore, entry) {
            if (chan_datastore->info != &stir_shaken_datastore_info) {
                continue;
            }
            count++;
        }
        ast_channel_unlock(chan);
 
        snprintf(buf, len, "%zu", count);
        return 0;
    }
 
    /* If we aren't doing a count, then there should be two parameters. The field
     * we are searching for will be the second parameter. The index is the first.
     */
    if (ast_strlen_zero(second)) {
        ast_log(LOG_ERROR, "Retrieving a value using %s requires two paramaters (index, value) "
            "- only index was given\n", function);
        return -1;
    }
 
    if (ast_str_to_uint(first, &target_index)) {
        ast_log(LOG_ERROR, "Failed to convert index %s to integer for function %s\n",
            first, function);
        return -1;
    }
 
    /* We don't store by uid for the datastore, so just search for the specified index */
    ast_channel_lock(chan);
    AST_LIST_TRAVERSE(ast_channel_datastores(chan), chan_datastore, entry) {
        if (chan_datastore->info != &stir_shaken_datastore_info) {
            continue;
        }
 
        if (current_index == target_index) {
            break;
        }
 
        current_index++;
    }
    ast_channel_unlock(chan);
    if (current_index != target_index || !chan_datastore) {
        ast_log(LOG_WARNING, "No STIR/SHAKEN results for index '%s'\n", first);
        return -1;
    }
    stir_datastore = chan_datastore->data;
 
    if (!strcasecmp(second, "identity")) {
        ast_copy_string(buf, stir_datastore->identity, len);
    } else if (!strcasecmp(second, "attestation")) {
        ast_copy_string(buf, stir_datastore->attestation, len);
    } else if (!strcasecmp(second, "verify_result")) {
        ast_copy_string(buf, vs_response_code_to_str(stir_datastore->verify_result), len);
    } else {
        ast_log(LOG_ERROR, "No such value '%s' for %s\n", second, function);
        return -1;
    }
 
    return 0;
}

References args, AST_APP_ARG, ast_channel_datastores(), ast_channel_lock, ast_channel_unlock, ast_copy_string(), AST_DECLARE_APP_ARGS, AST_LIST_TRAVERSE, ast_log, AST_STANDARD_APP_ARGS, ast_str_to_uint(), ast_strdupa, ast_strip(), ast_strlen_zero(), stir_datastore::attestation, buf, ast_datastore::data, ast_datastore::entry, first, stir_datastore::identity, ast_datastore::info, len(), LOG_ERROR, LOG_WARNING, stir_shaken_datastore_info, stir_datastore::verify_result, and vs_response_code_to_str().

get_tn_auth_nid()

int get_tn_auth_nid

(

void

)

Retrieves the OpenSSL NID for the TN Auth list extension.

Return values

The

NID

Definition at line 41 of file res_stir_shaken.c.

{
    return tn_auth_list_nid;
}

References tn_auth_list_nid.

Referenced by check_tn_auth_list().

load_module()

static int load_module ( void  )

static

Definition at line 347 of file res_stir_shaken.c.

{
    int res = 0;
 
    res = check_for_old_config();
    if (res != AST_MODULE_LOAD_SUCCESS) {
        return res;
    }
 
    res = crypto_load();
    if (res != AST_MODULE_LOAD_SUCCESS) {
        return res;
    }
 
    tn_auth_list_nid = crypto_register_x509_extension(TN_AUTH_LIST_OID,
        TN_AUTH_LIST_SHORT, TN_AUTH_LIST_LONG);
    if (tn_auth_list_nid < 0) {
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    res = common_config_load();
    if (res != AST_MODULE_LOAD_SUCCESS) {
        unload_module();
        return res;
    }
 
    res = ast_custom_function_register(&stir_shaken_function);
    if (res != 0) {
        unload_module();
        return AST_MODULE_LOAD_DECLINE;
    }
 
    return AST_MODULE_LOAD_SUCCESS;
}

References ast_custom_function_register, AST_MODULE_LOAD_DECLINE, AST_MODULE_LOAD_SUCCESS, check_for_old_config(), common_config_load(), crypto_load(), crypto_register_x509_extension(), stir_shaken_function, TN_AUTH_LIST_LONG, tn_auth_list_nid, TN_AUTH_LIST_OID, TN_AUTH_LIST_SHORT, and unload_module().

reload_module()

static int reload_module ( void  )

static

Definition at line 281 of file res_stir_shaken.c.

{
    return common_config_reload();
}

References common_config_reload().

stir_datastore_destroy_cb()

static void stir_datastore_destroy_cb ( void *  data )

static

The callback to destroy a stir_shaken_datastore.

Parameters

data	The stir_shaken_datastore

Definition at line 77 of file res_stir_shaken.c.

{
    struct stir_datastore *datastore = data;
    stir_datastore_free(datastore);
}

References stir_datastore_free().

stir_datastore_free()

static void stir_datastore_free ( struct stir_datastore *  datastore )

static

Frees a stir_shaken_datastore structure.

Parameters

datastore

The datastore to free

Definition at line 61 of file res_stir_shaken.c.

{
    if (!datastore) {
        return;
    }
 
    ast_free(datastore->identity);
    ast_free(datastore->attestation);
    ast_free(datastore);
}

References ast_free, stir_datastore::attestation, and stir_datastore::identity.

Referenced by ast_stir_shaken_add_result_to_channel(), and stir_datastore_destroy_cb().

unload_module()

static int unload_module ( void  )

static

Definition at line 286 of file res_stir_shaken.c.

{
    int res = 0;
 
    common_config_unload();
    crypto_unload();
 
    res |= ast_custom_function_unregister(&stir_shaken_function);
 
    return 0;
}

References ast_custom_function_unregister(), common_config_unload(), crypto_unload(), and stir_shaken_function.

Referenced by load_module().

Variable Documentation

__mod_info

struct ast_module_info __mod_info = { .name = AST_MODULE, .flags = AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER , .description = "STIR/SHAKEN Module for Asterisk" , .key = ASTERISK_GPL_KEY , .buildopt_sum = AST_BUILDOPT_SUM, .support_level = AST_MODULE_SUPPORT_CORE, .load = load_module, .unload = unload_module, .reload = reload_module, .load_pri = AST_MODPRI_CHANNEL_DEPEND - 1, .requires = "res_curl", }

static

Definition at line 390 of file res_stir_shaken.c.

ast_module_info

const struct ast_module_info* ast_module_info = &__mod_info

static

Definition at line 390 of file res_stir_shaken.c.

stir_shaken_datastore_info

const struct ast_datastore_info stir_shaken_datastore_info

static

Initial value:

= {
    .type = "STIR/SHAKEN VERIFICATION",
    .destroy = stir_datastore_destroy_cb,
}

Definition at line 84 of file res_stir_shaken.c.

                                                                    {
    .type = "STIR/SHAKEN VERIFICATION",
    .destroy = stir_datastore_destroy_cb,
};

Referenced by ast_stir_shaken_add_result_to_channel(), and func_read().

stir_shaken_function

struct ast_custom_function stir_shaken_function

static

Initial value:

= {
    .name = "STIR_SHAKEN",
    .read = func_read,
}

Definition at line 276 of file res_stir_shaken.c.

                                                         {
    .name = "STIR_SHAKEN",
    .read = func_read,
};

Referenced by load_module(), and unload_module().

tn_auth_list_nid

int tn_auth_list_nid

static

Definition at line 39 of file res_stir_shaken.c.

Referenced by get_tn_auth_nid(), and load_module().