int s2n_cipher_suites_init()

in tls/s2n_cipher_suites.c [992:1047]

• 41 lines of code
• 9 McCabe index (conditional complexity)

int s2n_cipher_suites_init(void)
{
    const int num_cipher_suites = s2n_array_len(s2n_all_cipher_suites);
    for (int i = 0; i < num_cipher_suites; i++) {
        struct s2n_cipher_suite *cur_suite = s2n_all_cipher_suites[i];
        cur_suite->available = 0;
        cur_suite->record_alg = NULL;

        /* Find the highest priority supported record algorithm */
        for (int j = 0; j < cur_suite->num_record_algs; j++) {
            /* Can we use the record algorithm's cipher? Won't be available if the system CPU architecture
             * doesn't support it or if the libcrypto lacks the feature. All hmac_algs are supported.
             */
            if (cur_suite->all_record_algs[j]->cipher->is_available()) {
                /* Found a supported record algorithm. Use it. */
                cur_suite->available = 1;
                cur_suite->record_alg = cur_suite->all_record_algs[j];
                break;
            }
        }

        /* Mark PQ cipher suites as unavailable if PQ is disabled */
        if (s2n_kex_includes(cur_suite->key_exchange_alg, &s2n_kem) && !s2n_pq_is_enabled()) {
            cur_suite->available = 0;
            cur_suite->record_alg = NULL;
        }

        /* Initialize SSLv3 cipher suite if SSLv3 utilizes a different record algorithm */
        if (cur_suite->sslv3_record_alg && cur_suite->sslv3_record_alg->cipher->is_available()) {
            struct s2n_blob cur_suite_mem = { 0 };
            POSIX_GUARD(s2n_blob_init(&cur_suite_mem, (uint8_t *) cur_suite, sizeof(struct s2n_cipher_suite)));
            struct s2n_blob new_suite_mem = { 0 };
            POSIX_GUARD(s2n_dup(&cur_suite_mem, &new_suite_mem));

            struct s2n_cipher_suite *new_suite = (struct s2n_cipher_suite *) (void *) new_suite_mem.data;
            new_suite->available = 1;
            new_suite->record_alg = cur_suite->sslv3_record_alg;
            cur_suite->sslv3_cipher_suite = new_suite;
        } else {
            cur_suite->sslv3_cipher_suite = cur_suite;
        }
    }

    if (should_init_crypto) {
#if !S2N_OPENSSL_VERSION_AT_LEAST(1, 1, 0)
        /*https://wiki.openssl.org/index.php/Manual:OpenSSL_add_all_algorithms(3)*/
        OpenSSL_add_all_algorithms();
#else
        OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CRYPTO_STRINGS | OPENSSL_INIT_ADD_ALL_CIPHERS | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);
#endif
    }

    crypto_initialized = true;

    return S2N_SUCCESS;
}