Revert commits after 089e185bd8

hosts/x1g13/default.nix

@@ -8,4 +8,7 @@
   boot.initrd.luks.devices.cryptroot.device =
     "/dev/disk/by-partuuid/311d0f9c-f35f-42e6-b6fc-a4d67dd21b2e";
 
+  my.applications.git.homeManager = {
+    signingKey = "~/.ssh/id_ed25519_sk_rk.pub";
+  };
 }

modules/applications/git/home.nix

@@ -1,156 +1,32 @@
 {
-  pkgs,
   lib,
   config,
   ...
 }:
-
 let
   cfg = config.my.applications.git;
   hmCfg = config.my.applications.git.homeManager;
-
-  sshCfg = config.my.applications.ssh;
-
-  gitSshSigningKeyCommand = pkgs.writeShellScript "git-ssh-signing-key" ''
-    set -u
-
-    expand_path() {
-      case "$1" in
-        "~")
-          printf '%s\n' "$HOME"
-          ;;
-        "~/"*)
-          printf '%s\n' "$HOME/''${1#"~/"}"
-          ;;
-        *)
-          printf '%s\n' "$1"
-          ;;
-      esac
-    }
-
-    fido_present() {
-      ${pkgs.libfido2}/bin/fido2-token -L 2>/dev/null \
-        | ${pkgs.gnugrep}/bin/grep -q .
-    }
-
-    is_ssh_public_key() {
-      case "$1" in
-        ssh-*|ecdsa-*|sk-*)
-          return 0
-          ;;
-        *)
-          return 1
-          ;;
-      esac
-    }
-
-    is_fido_public_key() {
-      case "$1" in
-        sk-*)
-          return 0
-          ;;
-        *)
-          return 1
-          ;;
-      esac
-    }
-
-    print_git_key() {
-      key="$1"
-
-      is_ssh_public_key "$key" || return 1
-
-      printf 'key::%s\n' "$key"
-      exit 0
-    }
-
-    pubkey_file_for_identity() {
-      identity_file="$(expand_path "$1")"
-
-      case "$identity_file" in
-        *.pub)
-          printf '%s\n' "$identity_file"
-          ;;
-        *)
-          printf '%s.pub\n' "$identity_file"
-          ;;
-      esac
-    }
-
-    print_pubkey_file_as_git_key() {
-      public_key_file="$1"
-
-      [ -r "$public_key_file" ] || return 1
-
-      IFS= read -r key < "$public_key_file" || return 1
-      [ -n "$key" ] || return 1
-
-      print_git_key "$key"
-    }
-
-    print_first_usable_agent_key() {
-      [ -n "''${SSH_AUTH_SOCK:-}" ] || return 1
-      [ -S "$SSH_AUTH_SOCK" ] || return 1
-
-      has_fido=0
-      if fido_present; then
-        has_fido=1
-      fi
-
-      ${pkgs.openssh}/bin/ssh-add -L 2>/dev/null \
-        | while IFS= read -r key; do
-            is_ssh_public_key "$key" || continue
-
-            # YubiKey が無いときに agent に残っている sk-* 鍵を選ぶと、
-            # Git 署名時に "agent refused operation" になる。
-            if is_fido_public_key "$key" && [ "$has_fido" -ne 1 ]; then
-              continue
-            fi
-
-            print_git_key "$key"
-          done
-    }
-
-    add_identity_to_agent_and_print_pubkey() {
-      identity_file="$(expand_path "$1")"
-      public_key_file="$(pubkey_file_for_identity "$1")"
-
-      [ -r "$identity_file" ] || return 1
-      [ -r "$public_key_file" ] || return 1
-
-      [ -n "''${SSH_AUTH_SOCK:-}" ] || return 1
-      [ -S "$SSH_AUTH_SOCK" ] || return 1
-
-      ${pkgs.openssh}/bin/ssh-add -q "$identity_file" >/dev/null 2>&1 || return 1
-
-      print_pubkey_file_as_git_key "$public_key_file"
-    }
-
-    # 1. agent にすでにある鍵を優先する。
-    # ただし YubiKey が無い場合、stale な sk-* 鍵は無視する。
-    print_first_usable_agent_key || true
-
-    # 2. YubiKey が刺さっている場合だけ _sk_rk を追加して使う。
-    if fido_present; then
-      add_identity_to_agent_and_print_pubkey ${lib.escapeShellArg sshCfg.fidoIdentityFile} || true
-    fi
-
-    # 3. 最後に通常のローカル鍵を agent に追加して使う。
-    ${lib.concatMapStringsSep "\n" (
-      identityFile: "add_identity_to_agent_and_print_pubkey ${lib.escapeShellArg identityFile} || true"
-    ) sshCfg.defaultIdentityFiles}
-
-    printf '%s\n' "git-ssh-signing-key: no usable SSH signing key found" >&2
-    exit 1
-  '';
-
 in
 {
   options.my.applications.git.homeManager = {
     enable = lib.mkEnableOption "git home-manager configuration";
+
+    signingKey = lib.mkOption {
+      type = lib.types.nullOr lib.types.str;
+      default = "~/.ssh/id_ed25519_sk_rk.pub";
+      example = "~/.ssh/id_ed25519.pub";
+      description = "SSH public key path used for Git commit and tag signing.";
+    };
   };
 
   config = lib.mkIf hmCfg.enable {
+    assertions = [
+      {
+        assertion = hmCfg.signingKey != null;
+        message = "my.applications.git.homeManager.signingKey must be set per host.";
+      }
+    ];
+
     home-manager.sharedModules = [
       {
         programs.git = {
@@ -162,6 +38,12 @@ in
             "!.envrc.example"
           ];
 
+          signing = {
+            key = hmCfg.signingKey;
+            format = "ssh";
+            signByDefault = true;
+          };
+
           settings = {
             user.name = cfg.userName;
             user.email = cfg.userEmail;
@@ -173,20 +55,6 @@ in
             log.date = "iso";
             merge.conflictStyle = "diff3";
 
-            # SSH signing
-            gpg.format = "ssh";
-
-            # Git の SSH signing backend はデフォルトでも ssh-keygen だが、
-            # store path に固定して PATH 依存を避ける。
-            gpg.ssh.program = "${pkgs.openssh}/bin/ssh-keygen";
-
-            # user.signingKey は固定しない。
-            # 署名時にこの command が key::ssh-ed25519 ... を返す。
-            gpg.ssh.defaultKeyCommand = "${gitSshSigningKeyCommand}";
-
-            commit.gpgSign = true;
-            tag.gpgSign = true;
-
             alias = {
               br = "branch --sort=-committerdate";
               co = "checkout";

modules/applications/openssh.nix

@@ -16,7 +16,6 @@ in
         PermitRootLogin = "no";
         PasswordAuthentication = false;
         KbdInteractiveAuthentication = false;
-        AllowAgentForwarding = true;
         PubkeyAuthentication = "yes";
       };
     };

modules/applications/ssh/default.nix

@@ -3,7 +3,6 @@
   config,
   ...
 }:
-
 let
   cfg = config.my.applications.ssh;
 in
@@ -14,71 +13,33 @@ in
   ];
 
   options.my.applications.ssh = {
-    enable = lib.mkEnableOption "OpenSSH client and agent configuration";
+    enable = lib.mkEnableOption "OpenSSH client";
 
-    defaultIdentityFiles = lib.mkOption {
-      type = lib.types.listOf lib.types.str;
-      default = [
-        "~/.ssh/id_ed25519"
-      ];
-      description = ''
-        Default local SSH identity files.
-
-        These are used as the normal fallback identities when no agent key
-        is accepted, or when no forwarded agent is available.
-      '';
-    };
-
-    fidoIdentityFile = lib.mkOption {
+    defaultIdentityFile = lib.mkOption {
       type = lib.types.str;
-      default = "~/.ssh/id_ed25519_sk_rk";
-      description = ''
-        Local FIDO2 resident-key SSH identity handle.
-
-        This file is only added to SSH identity candidates when a FIDO2
-        device is actually visible. Do not use file existence to decide
-        whether this key is usable.
-      '';
-    };
-
-    githubIdentityFiles = lib.mkOption {
-      type = lib.types.listOf lib.types.str;
-      default = [ ];
-      description = ''
-        Extra GitHub-specific SSH identity files.
-
-        Leave this empty if GitHub should use the normal agent, FIDO key,
-        and default identity fallback order.
-      '';
+      default = "~/.ssh/id_ed25519";
+      description = "Default SSH identity file";
     };
 
     addKeysToAgent = lib.mkOption {
       type = lib.types.str;
       default = "no";
-      example = "1h";
-      description = ''
-        Value for OpenSSH AddKeysToAgent.
-
-        Recommended default is "no" for this setup, because FIDO resident-key
-        handle files should not be added to the agent accidentally.
-      '';
+      description = "Add keys to SSH agent";
     };
 
     matchBlocks = lib.mkOption {
-      type = lib.types.attrsOf lib.types.anything;
+      type = lib.types.attrs;
       default = { };
-      description = ''
-        Additional Home Manager OpenSSH settings blocks.
-
-        Use this for host-specific options such as ForwardAgent = true.
-      '';
-      example = lib.literalExpression ''
-        {
-          "proxmox-* *.home.arpa *.internal" = {
-            ForwardAgent = true;
+      description = "SSH match blocks";
     };
-        }
-      '';
+
+    githubIdentityFiles = lib.mkOption {
+      type = lib.types.listOf lib.types.str;
+      default = [
+        "~/.ssh/id_ed25519_sk_rk"
+        "~/.ssh/id_ed25519"
+      ];
+      description = "SSH identity files for GitHub (tried in order)";
     };
   };
 

modules/applications/ssh/home.nix

@@ -4,146 +4,9 @@
   config,
   ...
 }:
-
 let
   cfg = config.my.applications.ssh;
   hmCfg = config.my.applications.ssh.homeManager;
-
-  shellPathExpr =
-    path:
-    if lib.hasPrefix "~/" path then
-      ''"$HOME/${lib.removePrefix "~/" path}"''
-    else
-      lib.escapeShellArg path;
-
-  fidoIdentityExpr = shellPathExpr cfg.fidoIdentityFile;
-
-  hasFidoDevice = pkgs.writeShellScript "ssh-has-fido-device" ''
-    ${pkgs.libfido2}/bin/fido2-token -L 2>/dev/null \
-      | ${pkgs.gnugrep}/bin/grep -q .
-  '';
-
-  sshYubikeyAgentSync = pkgs.writeShellApplication {
-    name = "ssh-yubikey-agent-sync";
-
-    runtimeInputs = with pkgs; [
-      openssh
-      libfido2
-      coreutils
-      gnugrep
-      gawk
-    ];
-
-    text = ''
-      set -u
-
-      force=0
-
-      case "''${1:-}" in
-        "")
-          ;;
-        "--force")
-          force=1
-          ;;
-        *)
-          printf '%s\n' "usage: ssh-yubikey-agent-sync [--force]" >&2
-          exit 2
-          ;;
-      esac
-
-      if [ -z "''${XDG_RUNTIME_DIR:-}" ]; then
-        exit 0
-      fi
-
-      export SSH_AUTH_SOCK="$XDG_RUNTIME_DIR/ssh-agent"
-
-      if [ ! -S "$SSH_AUTH_SOCK" ]; then
-        exit 0
-      fi
-
-      fido_identity=${fidoIdentityExpr}
-      fido_public_key="$fido_identity.pub"
-
-      state_dir="$XDG_RUNTIME_DIR/ssh-yubikey-agent-sync"
-      state_file="$state_dir/fido-device-state"
-
-      mkdir -p "$state_dir"
-
-      fido_present() {
-        fido2-token -L 2>/dev/null | grep -q .
-      }
-
-      fido_state() {
-        fido2-token -L 2>/dev/null | sha256sum | awk '{ print $1 }'
-      }
-
-      pub_fingerprint() {
-        [ -r "$1" ] || return 1
-        ssh-keygen -lf "$1" -E sha256 2>/dev/null | awk '{ print $2 }'
-      }
-
-      agent_has_public_key() {
-        public_key_file="$1"
-
-        fingerprint="$(pub_fingerprint "$public_key_file")" || return 1
-
-        ssh-add -l -E sha256 2>/dev/null \
-          | grep -Fq "$fingerprint"
-      }
-
-      remove_fido_from_agent() {
-        ssh-add -d "$fido_identity" >/dev/null 2>&1 || true
-        ssh-add -d "$fido_public_key" >/dev/null 2>&1 || true
-      }
-
-      add_fido_to_agent() {
-        [ -r "$fido_identity" ] || exit 0
-        [ -r "$fido_public_key" ] || exit 0
-
-        remove_fido_from_agent
-
-        ssh-add -q -t "''${SSH_YUBIKEY_AGENT_LIFETIME:-24h}" "$fido_identity" >/dev/null 2>&1 || exit 0
-      }
-
-      if fido_present; then
-        new_state="$(fido_state)"
-        old_state="$(cat "$state_file" 2>/dev/null || true)"
-
-        if [ "$force" -eq 1 ] \
-          || ! agent_has_public_key "$fido_public_key" \
-          || [ "$new_state" != "$old_state" ]; then
-          add_fido_to_agent
-          printf '%s\n' "$new_state" > "$state_file"
-        fi
-      else
-        remove_fido_from_agent
-        rm -f "$state_file"
-      fi
-    '';
-  };
-
-  userMatchBlockNames = lib.attrNames (cfg.matchBlocks or { });
-
-  userMatchBlocks = lib.mapAttrs (
-    _name: value: lib.hm.dag.entryBefore [ "my-github" "my-default" ] value
-  ) (cfg.matchBlocks or { });
-
-  githubBlock = {
-    header = "Host github.com";
-
-    HostName = "github.com";
-    User = "git";
-
-    IdentityAgent = "SSH_AUTH_SOCK";
-    IdentitiesOnly = false;
-    ForwardAgent = false;
-
-    AddKeysToAgent = cfg.addKeysToAgent;
-  }
-  // lib.optionalAttrs (cfg.githubIdentityFiles != [ ]) {
-    IdentityFile = cfg.githubIdentityFiles;
-  };
-
 in
 {
   options.my.applications.ssh.homeManager = {
@@ -151,100 +14,33 @@ in
   };
 
   config.home-manager.sharedModules = [
-    (
-      { lib, ... }:
     {
       config = lib.mkIf hmCfg.enable {
         home.packages = [
-            sshYubikeyAgentSync
+          pkgs.openssh
         ];
 
-          systemd.user.services.ssh-yubikey-agent-sync = {
-            Unit = {
-              Description = "Synchronize YubiKey SSH key with ssh-agent";
-            };
+        systemd.user.sockets.gcr-ssh-agent.Install.WantedBy = lib.mkForce [ ];
 
-            Service = {
-              Type = "oneshot";
+        services.ssh-agent.enable = true;
 
-              # NixOS programs.ssh.startAgent の socket。
-              Environment = [
-                "SSH_AUTH_SOCK=%t/ssh-agent"
-                "SSH_YUBIKEY_AGENT_LIFETIME=24h"
-              ];
-
-              ExecStart = "${sshYubikeyAgentSync}/bin/ssh-yubikey-agent-sync";
-            };
-          };
-
-          systemd.user.timers.ssh-yubikey-agent-sync = {
-            Unit = {
-              Description = "Periodically synchronize YubiKey SSH key with ssh-agent";
-            };
-
-            Timer = {
-              OnBootSec = "5s";
-              OnUnitActiveSec = "10s";
-              AccuracySec = "2s";
-              Unit = "ssh-yubikey-agent-sync.service";
-            };
-
-            Install = {
-              WantedBy = [ "timers.target" ];
-            };
+        home.sessionVariables = {
+          SSH_AUTH_SOCK = "\${XDG_RUNTIME_DIR}/ssh-agent";
         };
 
         programs.ssh = {
           enable = true;
           enableDefaultConfig = false;
 
-            settings = userMatchBlocks // {
-              "my-local-fido-sk-rk" =
-                lib.hm.dag.entryBefore
-                  (
-                    [
-                      "my-github"
-                      "my-default"
-                    ]
-                    ++ userMatchBlockNames
-                  )
-                  {
-                    header = ''Match exec "${hasFidoDevice}"'';
-
-                    IdentityFile = cfg.fidoIdentityFile;
-
-                    # FIDO key の agent 登録は ssh-yubikey-agent-sync に任せる。
-                    #
-                    # ここで AddKeysToAgent を有効にすると、
-                    # YubiKey 抜き差し後に stale な agent entry が残りやすい。
-                    AddKeysToAgent = "no";
+          settings = cfg.matchBlocks // {
+            "github.com" = {
+              IdentityFile = cfg.githubIdentityFiles;
+              AddKeysToAgent = cfg.addKeysToAgent;
             };
 
-              "my-github" = lib.hm.dag.entryBefore [ "my-default" ] githubBlock;
-
-              "my-default" =
-                lib.hm.dag.entryAfter
-                  (
-                    [
-                      "my-local-fido-sk-rk"
-                      "my-github"
-                    ]
-                    ++ userMatchBlockNames
-                  )
-                  {
-                    header = "Host *";
-
-                    IdentityAgent = "SSH_AUTH_SOCK";
-                    IdentitiesOnly = false;
-
-                    # default deny。
-                    # agent forwarding したい host だけ cfg.matchBlocks 側で true にする。
-                    ForwardAgent = false;
-
-                    IdentityFile = cfg.defaultIdentityFiles;
-
+            "*" = {
+              IdentityFile = cfg.defaultIdentityFile;
               AddKeysToAgent = cfg.addKeysToAgent;
-
               SetEnv = {
                 TERM = "xterm";
               };
@@ -253,6 +49,5 @@ in
         };
       };
     }
-    )
   ];
 }

modules/applications/ssh/system.nix

@@ -15,14 +15,9 @@ in
   config = lib.mkIf cfg.enable {
     environment.systemPackages = with pkgs; [
       openssh # OpenSSH client and server
-      libfido2 # FIDO2 support for SSH
     ];
 
-    programs.ssh = {
-      startAgent = true;
-      agentTimeout = "24h";
-    };
-    programs.gnupg.agent.enableSSHSupport = lib.mkForce false;
-    services.gnome.gcr-ssh-agent.enable = lib.mkForce false;
+    programs.ssh.startAgent = false;
+    services.gnome.gcr-ssh-agent.enable = false;
   };
 }