bool s_resolve_hmac_lc()

in source/unix/openssl_platform_init.c [185:231]

• 39 lines of code
• 10 McCabe index (conditional complexity)

bool s_resolve_hmac_lc(void *module) {
#if defined(OPENSSL_IS_AWSLC)
    hmac_ctx_init init_fn = (hmac_ctx_init)HMAC_CTX_init;
    hmac_ctx_clean_up clean_up_fn = (hmac_ctx_clean_up)HMAC_CTX_cleanup;
    hmac_ctx_new new_fn = (hmac_ctx_new)HMAC_CTX_new;
    hmac_ctx_free free_fn = (hmac_ctx_free)HMAC_CTX_free;
    hmac_ctx_reset reset_fn = (hmac_ctx_reset)HMAC_CTX_reset;
    hmac_ctx_update update_fn = (hmac_ctx_update)HMAC_Update;
    hmac_ctx_final final_fn = (hmac_ctx_final)HMAC_Final;
    hmac_ctx_init_ex init_ex_fn = (hmac_ctx_init_ex)HMAC_Init_ex;

    /* were symbols bound by static linking? */
    bool has_awslc_symbols = new_fn && free_fn && update_fn && final_fn && init_fn && init_ex_fn && reset_fn;

    /* If symbols aren't already found, try to find the requested version */
    /* when built as a shared lib, and multiple versions of libcrypto are possibly
     * available (e.g. brazil), select AWS-LC by default for consistency */
    if (has_awslc_symbols) {
        AWS_LOGF_DEBUG(AWS_LS_CAL_LIBCRYPTO_RESOLVE, "found static aws-lc HMAC symbols");
    } else {
        *(void **)(&new_fn) = dlsym(module, "HMAC_CTX_new");
        *(void **)(&reset_fn) = dlsym(module, "HMAC_CTX_reset");
        *(void **)(&free_fn) = dlsym(module, "HMAC_CTX_free");
        *(void **)(&update_fn) = dlsym(module, "HMAC_Update");
        *(void **)(&final_fn) = dlsym(module, "HMAC_Final");
        *(void **)(&init_ex_fn) = dlsym(module, "HMAC_Init_ex");
        if (new_fn) {
            AWS_LOGF_DEBUG(AWS_LS_CAL_LIBCRYPTO_RESOLVE, "found dynamic aws-lc HMAC symbols");
        }
    }

    if (new_fn) {
        /* Fill out the vtable for the requested version */
        hmac_ctx_table.new_fn = new_fn;
        hmac_ctx_table.reset_fn = reset_fn;
        hmac_ctx_table.free_fn = free_fn;
        hmac_ctx_table.init_fn = init_fn;
        hmac_ctx_table.clean_up_fn = clean_up_fn;
        hmac_ctx_table.update_fn = update_fn;
        hmac_ctx_table.final_fn = final_fn;
        hmac_ctx_table.init_ex_fn = init_ex_fn;
        g_aws_openssl_hmac_ctx_table = &hmac_ctx_table;
        return true;
    }
#endif
    return false;
}