godot/thirdparty/mbedtls/library/ssl_cookie.c

/*
 *  DTLS cookie callbacks implementation
 *
 *  Copyright The Mbed TLS Contributors
 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
 */
/*
 * These session callbacks use a simple chained list
 * to store and retrieve the session information.
 */

#include "common.h"

#if defined(MBEDTLS_SSL_COOKIE_C)

#include "mbedtls/platform.h"

#include "mbedtls/ssl_cookie.h"
#include "ssl_misc.h"
#include "mbedtls/error.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/constant_time.h"

#include <string.h>

#if defined(MBEDTLS_USE_PSA_CRYPTO)
#include "mbedtls/psa_util.h"
/* Define a local translating function to save code size by not using too many
 * arguments in each translating place. */
static int local_err_translation(psa_status_t status)
{
    return psa_status_to_mbedtls(status, psa_to_ssl_errors,
                                 ARRAY_LENGTH(psa_to_ssl_errors),
                                 psa_generic_status_to_mbedtls);
}
#define PSA_TO_MBEDTLS_ERR …
#endif

/*
 * If DTLS is in use, then at least one of SHA-256 or SHA-384 is
 * available. Try SHA-256 first as 384 wastes resources
 */
#if defined(MBEDTLS_MD_CAN_SHA256)
#define COOKIE_MD …
#define COOKIE_MD_OUTLEN …
#define COOKIE_HMAC_LEN …
#elif defined(MBEDTLS_MD_CAN_SHA384)
#define COOKIE_MD …
#define COOKIE_MD_OUTLEN …
#define COOKIE_HMAC_LEN …
#else
#error "DTLS hello verify needs SHA-256 or SHA-384"
#endif

/*
 * Cookies are formed of a 4-bytes timestamp (or serial number) and
 * an HMAC of timestamp and client ID.
 */
#define COOKIE_LEN …

void mbedtls_ssl_cookie_init(mbedtls_ssl_cookie_ctx *ctx)
{ … }

void mbedtls_ssl_cookie_set_timeout(mbedtls_ssl_cookie_ctx *ctx, unsigned long delay)
{ … }

void mbedtls_ssl_cookie_free(mbedtls_ssl_cookie_ctx *ctx)
{ … }

int mbedtls_ssl_cookie_setup(mbedtls_ssl_cookie_ctx *ctx,
                             int (*f_rng)(void *, unsigned char *, size_t),
                             void *p_rng)
{ … }

#if !defined(MBEDTLS_USE_PSA_CRYPTO)
/*
 * Generate the HMAC part of a cookie
 */
MBEDTLS_CHECK_RETURN_CRITICAL
static int ssl_cookie_hmac(mbedtls_md_context_t *hmac_ctx,
                           const unsigned char time[4],
                           unsigned char **p, unsigned char *end,
                           const unsigned char *cli_id, size_t cli_id_len)
{ … }
#endif /* !MBEDTLS_USE_PSA_CRYPTO */

/*
 * Generate cookie for DTLS ClientHello verification
 */
int mbedtls_ssl_cookie_write(void *p_ctx,
                             unsigned char **p, unsigned char *end,
                             const unsigned char *cli_id, size_t cli_id_len)
{ … }

/*
 * Check a cookie
 */
int mbedtls_ssl_cookie_check(void *p_ctx,
                             const unsigned char *cookie, size_t cookie_len,
                             const unsigned char *cli_id, size_t cli_id_len)
{ … }
#endif /* MBEDTLS_SSL_COOKIE_C */