Repository: bitcoin/bitcoin
File: src/httprpc.cpp (C++)

Code before:

static bool InitRPCAuthentication()
{
    if (gArgs.GetArg("-rpcpassword", "") == "")
    {
        LogInfo("Using random cookie authentication.\n");

        std::optional<fs::perms> cookie_perms{std::nullopt};
        auto cookie_perms_arg{gArgs.GetArg("-rpccookieperms")};
        if (cookie_perms_arg) {
            auto perm_opt = InterpretPermString(*cookie_perms_arg);
            if (!perm_opt) {
                LogInfo("Invalid -rpccookieperms=%s; must be one of 'owner', 'group', or 'all'.\n", *cookie_perms_arg);
                return false;
            }
            cookie_perms = *perm_opt;
        }

        if (!GenerateAuthCookie(&strRPCUserColonPass, cookie_perms)) {
            return false;
        }
    } else {
        LogPrintf("Config options rpcuser and rpcpassword will soon be deprecated. Locally-run instances may remove rpcuser to use cookie-based auth, or may be replaced with rpcauth. Please see share/rpcauth for rpcauth auth generation.\n");
        strRPCUserColonPass = gArgs.GetArg("-rpcuser", "") + ":" + gArgs.GetArg("-rpcpassword", "");
    }

    if (!gArgs.GetArgs("-rpcauth").empty()) {
        LogInfo("Using rpcauth authentication.\n");
        for (const std::string& rpcauth : gArgs.GetArgs("-rpcauth")) {
            std::vector<std::string> fields{SplitString(rpcauth, ':')};
            const std::vector<std::string> salt_hmac{SplitString(fields.back(), '$')};
            if (fields.size() == 2 && salt_hmac.size() == 2) {
                fields.pop_back();
                fields.insert(fields.end(), salt_hmac.begin(), salt_hmac.end());
                g_rpcauth.push_back(fields);
            } else {
                LogPrintf("Invalid -rpcauth argument.\n");
                return false;
            }
        }
    }

    g_rpc_whitelist_default = gArgs.GetBoolArg("-rpcwhitelistdefault", gArgs.IsArgSet("-rpcwhitelist"));
    for (const std::string& strRPCWhitelist : gArgs.GetArgs("-rpcwhitelist")) {
        auto pos = strRPCWhitelist.find(':');
        std::string strUser = strRPCWhitelist.substr(0, pos);
        bool intersect = g_rpc_whitelist.count(strUser);
        std::set<std::string>& whitelist = g_rpc_whitelist[strUser];
        if (pos != std::string::npos) {
            std::string strWhitelist = strRPCWhitelist.substr(pos + 1);
            std::vector<std::string> whitelist_split = SplitString(strWhitelist, ", ");

Review comment (security):
this seems like a slight behavior change: previously when `GenerateAuthCookie` returned `true`, this was logged, now it seems to me it may not be (haven't tried the code)

Code after:
static bool InitRPCAuthentication()
{
    if (gArgs.GetArg("-rpcpassword", "") == "")
    {
        std::optional<fs::perms> cookie_perms{std::nullopt};
        auto cookie_perms_arg{gArgs.GetArg("-rpccookieperms")};
        if (cookie_perms_arg) {
            auto perm_opt = InterpretPermString(*cookie_perms_arg);
            if (!perm_opt) {
                LogError("Invalid -rpccookieperms=%s; must be one of 'owner', 'group', or 'all'.", *cookie_perms_arg);
                return false;
            }
            cookie_perms = *perm_opt;
        }

        assert(strRPCUserColonPass.empty()); // Only support initializing once
        if (!GenerateAuthCookie(&strRPCUserColonPass, cookie_perms)) {
            return false;
        }
        if (strRPCUserColonPass.empty()) {
            LogInfo("RPC authentication cookie file generation is disabled.");
        } else {
            LogInfo("Using random cookie authentication.");
        }
    } else {
        LogPrintf("Config options rpcuser and rpcpassword will soon be deprecated. Locally-run instances may remove rpcuser to use cookie-based auth, or may be replaced with rpcauth. Please see share/rpcauth for rpcauth auth generation.\n");
        strRPCUserColonPass = gArgs.GetArg("-rpcuser", "") + ":" + gArgs.GetArg("-rpcpassword", "");
    }

    if (!gArgs.GetArgs("-rpcauth").empty()) {
        LogInfo("Using rpcauth authentication.\n");
        for (const std::string& rpcauth : gArgs.GetArgs("-rpcauth")) {
            std::vector<std::string> fields{SplitString(rpcauth, ':')};
            const std::vector<std::string> salt_hmac{SplitString(fields.back(), '$')};
            if (fields.size() == 2 && salt_hmac.size() == 2) {
                fields.pop_back();
                fields.insert(fields.end(), salt_hmac.begin(), salt_hmac.end());
                g_rpcauth.push_back(fields);
            } else {
                LogPrintf("Invalid -rpcauth argument.\n");
                return false;
            }
        }
    }

    g_rpc_whitelist_default = gArgs.GetBoolArg("-rpcwhitelistdefault", gArgs.IsArgSet("-rpcwhitelist"));
    for (const std::string& strRPCWhitelist : gArgs.GetArgs("-rpcwhitelist")) {
        auto pos = strRPCWhitelist.find(':');
        std::string strUser = strRPCWhitelist.substr(0, pos);
        bool intersect = g_rpc_whitelist.count(strUser);
        std::set<std::string>& whitelist = g_rpc_whitelist[strUser];