auth: add hyprlock-setpwhash target for setting the password hash

CMakeLists.txt

@@ -116,8 +116,12 @@ protocol("protocols/wlr-screencopy-unstable-v1.xml"
 protocol("unstable/linux-dmabuf/linux-dmabuf-unstable-v1.xml"
          "linux-dmabuf-unstable-v1" false)
 
+# hyprlock-setpwhash
+add_executable(hyprlock-setpwhash "setpwhash/main.cpp")
+target_link_libraries(hyprlock-setpwhash PRIVATE sodium hyprutils)
+
 # Installation
-install(TARGETS hyprlock)
+install(TARGETS hyprlock hyprlock-setpwhash)
 
 install(FILES ${CMAKE_SOURCE_DIR}/pam/hyprlock
         DESTINATION ${CMAKE_INSTALL_FULL_SYSCONFDIR}/pam.d)

setpwhash/main.cpp

@@ -0,0 +1,167 @@
+#include "../src/helpers/Log.hpp"
+
+#include <filesystem>
+#include <hyprutils/path/Path.hpp>
+#include <iostream>
+#include <fstream>
+#include <istream>
+#include <sodium.h>
+#include <string>
+#include <termios.h>
+#include <unistd.h>
+#include <print>
+
+using std::filesystem::perms;
+
+void setStdinEcho(bool enable = true) {
+    struct termios tty;
+    tcgetattr(STDIN_FILENO, &tty);
+    if (!enable)
+        tty.c_lflag &= ~ECHO;
+    else
+        tty.c_lflag |= ECHO;
+    RASSERT(tcsetattr(STDIN_FILENO, TCSANOW, &tty) == 0, "Failed to set terminal attributes");
+}
+
+// returns the first none-whitespace char
+int getChoice() {
+    std::string input;
+    std::getline(std::cin, input);
+    const auto p = input.find_first_not_of(" \n");
+    return (p == std::string::npos) ? 0 : input[p];
+}
+
+constexpr auto CHOOSELIMITSPROMPT = R"#(
+Choose how hard it will be to brute force your password.
+This also defines how long it will take to check the password.
+1 - interactive (least security, pretty fast checking)
+2 - moderate (medium security, takes below a second on most machines)
+3 - sensitive (decent security, takes around 2-4 seconds on most machines)
+
+Type 1, 2 or 3, or Enter for default (2): )#";
+
+unsigned int   getOpsLimit(int choice) {
+    switch (choice) {
+        case '1': return crypto_pwhash_OPSLIMIT_INTERACTIVE;
+        case '2': return crypto_pwhash_OPSLIMIT_MODERATE;
+        case '3': return crypto_pwhash_OPSLIMIT_SENSITIVE;
+        default: return crypto_pwhash_OPSLIMIT_MODERATE;
+    }
+    std::unreachable();
+}
+
+unsigned int getMemLimit(int choice) {
+    switch (choice) {
+        case '1': return crypto_pwhash_MEMLIMIT_INTERACTIVE;
+        case '2': return crypto_pwhash_MEMLIMIT_MODERATE;
+        case '3': return crypto_pwhash_MEMLIMIT_SENSITIVE;
+        default: return crypto_pwhash_MEMLIMIT_MODERATE;
+    }
+    std::unreachable();
+}
+
+void help() {
+    std::println("Usage: hyprlock-setpwhash\n"
+                 "Interactive utility to set the password hash for hyprlock");
+}
+
+int main(int argc, char** argv, char** envp) {
+    std::vector<std::string> args(argv, argv + argc);
+
+    RASSERT(sodium_init() >= 0, "Failed to initialize libsodium");
+
+    for (std::size_t i = 1; i < args.size(); ++i) {
+        const std::string arg = argv[i];
+
+        if (arg == "--help" || arg == "-h") {
+            help();
+            return 0;
+        } else {
+            std::cerr << "Unknown argument: " << arg << std::endl;
+            help();
+            return 1;
+        }
+    }
+
+    const auto [SECRETSCONF, DOTDIR] = Hyprutils::Path::findConfig("hyprlock_pwhash");
+    if (SECRETSCONF.has_value()) {
+        // check permissions
+        std::println("{} already exists.", SECRETSCONF.value());
+        std::print("Do you want to overwrite it? [y/N] ");
+        const auto CHOICE = getChoice();
+
+        if (CHOICE != 'y' && CHOICE != 'Y') {
+            std::println("Keeping existing secrets!");
+
+            const auto PERMS = std::filesystem::status(SECRETSCONF.value()).permissions();
+            if ((PERMS & perms::group_read) != perms::none || (PERMS & perms::group_write) != perms::none || (PERMS & perms::others_read) != perms::none ||
+                (PERMS & perms::others_write) != perms::none) {
+                std::println("Setting permissions of {} to -rw-------", SECRETSCONF.value());
+
+                // set perms to -rw-------
+                std::filesystem::permissions(SECRETSCONF.value(), perms::owner_read | perms::owner_write);
+            }
+            return 0;
+        }
+    }
+
+    RASSERT(DOTDIR.has_value(), "Failed to find config directory!");
+    const auto DEST = DOTDIR.value() + "/hypr/hyprlock_pwhash.conf";
+
+    std::println("Note: We are going to write a password hash to {}\n"
+                 "      If you choose a weak password and this hash gets leaked,\n"
+                 "      someone might be able to guess your password using a password list or brute force.\n"
+                 "      So best to keep it safe and (or) choose a good password.",
+                 DEST);
+
+    std::print(CHOOSELIMITSPROMPT);
+    const auto CHOICE = getChoice();
+
+    setStdinEcho(false);
+    std::string pw = "";
+    while (true) {
+        std::print("New password: ");
+        std::getline(std::cin, pw);
+        std::print("\r");
+
+        if (pw.empty()) {
+            std::println("Empty password");
+            continue;
+        }
+
+        if (pw.size() < 4) {
+            std::println("Less than 4 characters? Nope.");
+            continue;
+        }
+
+        std::string pw2 = "";
+        std::print("Repeat password: ");
+        std::getline(std::cin, pw2);
+        std::print("\r");
+
+        if (pw != pw2) {
+            std::println("Ups, passwords do not match");
+            continue;
+        }
+
+        break;
+    }
+    setStdinEcho(true);
+
+    char hash[crypto_pwhash_STRBYTES];
+    if (crypto_pwhash_str(hash, pw.c_str(), pw.size(), getOpsLimit(CHOICE), getMemLimit(CHOICE)) != 0) {
+        std::println("[Sodium] Failed to hash password");
+        return 1;
+    }
+
+    {
+        std::ofstream out(DEST);
+        out << "pw_hash = " << hash << std::endl;
+    }
+
+    // set perms to -rw-------
+    std::filesystem::permissions(DEST, perms::owner_read | perms::owner_write);
+
+    std::println("Done!");
+    return 0;
+}

src/auth/SodiumPWHash.cpp

@@ -72,30 +72,9 @@ void CSodiumPWHash::terminate() {
         m_checkerThread.join();
 }
 
-void CSodiumPWHash::rehash(std::string& input) {
-    const auto CONFIGPATH = getSecretsConfigPath();
-
-    char       hash[crypto_pwhash_STRBYTES];
-    if (crypto_pwhash_str(hash, input.c_str(), input.size(), crypto_pwhash_OPSLIMIT_MODERATE, crypto_pwhash_MEMLIMIT_MODERATE) != 0) {
-        Debug::log(ERR, "[Sodium] Failed to hash password");
-        return;
-    }
-
-    std::ofstream out(CONFIGPATH);
-    out << "hyprlock {\n  pw_hash = " << hash << "\n}\n";
-    out.close();
-
-    // set perms to -rw-------
-    using std::filesystem::perms;
-    std::filesystem::permissions(CONFIGPATH, perms::owner_read | perms::owner_write);
-}
-
 void CSodiumPWHash::checkerLoop() {
-    static auto* const PPWHASH     = (Hyprlang::STRING*)getConfigValuePtr("pw_hash");
-    const auto         PWHASH      = std::string(*PPWHASH);
-    const bool         NEEDSREHASH = crypto_pwhash_str_needs_rehash(PWHASH.c_str(), crypto_pwhash_OPSLIMIT_MODERATE, crypto_pwhash_MEMLIMIT_MODERATE) != 0;
-    if (NEEDSREHASH)
-        Debug::log(WARN, "[Sodium] Password hash needs rehashing");
+    static auto* const PPWHASH = (Hyprlang::STRING*)getConfigValuePtr("pw_hash");
+    const auto         PWHASH  = std::string(*PPWHASH);
 
     while (true) {
         std::unique_lock<std::mutex> lk(m_sCheckerState.requestMutex);
@@ -109,8 +88,6 @@ void CSodiumPWHash::checkerLoop() {
             Debug::log(ERR, "[SodiumAuth] Invalid password hash set in secrets.conf");
             g_pAuth->enqueueFail();
         } else if (crypto_pwhash_str_verify(PWHASH.c_str(), m_sCheckerState.input.c_str(), m_sCheckerState.input.length()) == 0) {
-            if (NEEDSREHASH)
-                rehash(m_sCheckerState.input);
             g_pAuth->enqueueUnlock();
         } else {
             g_pAuth->enqueueFail();

src/auth/SodiumPWHash.hpp

@@ -37,7 +37,5 @@ class CSodiumPWHash : public IAuthImplementation {
     std::thread       m_checkerThread;
     void              checkerLoop();
 
-    void              rehash(std::string& input);
-
     Hyprlang::CConfig m_config;
 };