GUI host key prompts: add 'More info' subdialog.

This behaves like the 'i' keystroke I just added to the console host
key prompts: it shows you all fingerprints and the full public key.

unix/gtkdlg.c

@@ -3426,20 +3426,24 @@ GtkWidget *create_message_box(
         NULL /* action_postproc */, NULL /* postproc_ctx */);
 }
 
-struct verify_ssh_host_key_result_ctx {
+struct verify_ssh_host_key_dialog_ctx {
     char *host;
     int port;
     char *keytype;
     char *keystr;
+    char *more_info;
     void (*callback)(void *callback_ctx, int result);
     void *callback_ctx;
     Seat *seat;
+
+    GtkWidget *main_dialog;
+    GtkWidget *more_info_dialog;
 };
 
 static void verify_ssh_host_key_result_callback(void *vctx, int result)
 {
-    struct verify_ssh_host_key_result_ctx *ctx =
+    struct verify_ssh_host_key_dialog_ctx *ctx =
-        (struct verify_ssh_host_key_result_ctx *)vctx;
+        (struct verify_ssh_host_key_dialog_ctx *)vctx;
 
     if (result >= 0) {
         int logical_result;
@@ -3468,12 +3472,51 @@ static void verify_ssh_host_key_result_callback(void *vctx, int result)
      */
     unregister_dialog(ctx->seat, DIALOG_SLOT_NETWORK_PROMPT);
 
+    if (ctx->more_info_dialog)
+        gtk_widget_destroy(ctx->more_info_dialog);
+
     sfree(ctx->host);
     sfree(ctx->keytype);
     sfree(ctx->keystr);
+    sfree(ctx->more_info);
     sfree(ctx);
 }
 
+static GtkWidget *add_more_info_button(GtkWidget *w, void *vctx)
+{
+    GtkWidget *box = gtk_hbox_new(false, 10);
+    gtk_widget_show(box);
+    gtk_box_pack_end(GTK_BOX(box), w, false, true, 0);
+    GtkWidget *button = gtk_button_new_with_label("More info...");
+    gtk_widget_show(button);
+    gtk_box_pack_start(GTK_BOX(box), button, false, true, 0);
+    *(GtkWidget **)vctx = button;
+    return box;
+}
+
+static void more_info_closed(void *vctx, int result)
+{
+    struct verify_ssh_host_key_dialog_ctx *ctx =
+        (struct verify_ssh_host_key_dialog_ctx *)vctx;
+
+    ctx->more_info_dialog = NULL;
+}
+
+static void more_info_button_clicked(GtkButton *button, gpointer vctx)
+{
+    struct verify_ssh_host_key_dialog_ctx *ctx =
+        (struct verify_ssh_host_key_dialog_ctx *)vctx;
+
+    if (ctx->more_info_dialog)
+        return;
+
+    ctx->more_info_dialog = create_message_box(
+        ctx->main_dialog, "Host key information", ctx->more_info,
+        string_width("SHA256 fingerprint: ecdsa-sha2-nistp521 521 "
+                     "abcdefghkmnopqrsuvwxyzABCDEFGHJKLMNOPQRSTUW"), true,
+        &buttons_ok, more_info_closed, ctx);
+}
+
 int gtk_seat_verify_ssh_host_key(
     Seat *seat, const char *host, int port, const char *keytype,
     char *keystr, const char *keydisp, char **fingerprints,
@@ -3516,7 +3559,7 @@ int gtk_seat_verify_ssh_host_key(
 
     char *text;
     int ret;
-    struct verify_ssh_host_key_result_ctx *result_ctx;
+    struct verify_ssh_host_key_dialog_ctx *result_ctx;
     GtkWidget *mainwin, *msgbox;
 
     /*
@@ -3533,7 +3576,7 @@ int gtk_seat_verify_ssh_host_key(
     text = dupprintf((ret == 2 ? wrongtxt : absenttxt), keytype,
                      fingerprints[fptype_default]);
 
-    result_ctx = snew(struct verify_ssh_host_key_result_ctx);
+    result_ctx = snew(struct verify_ssh_host_key_dialog_ctx);
     result_ctx->callback = callback;
     result_ctx->callback_ctx = ctx;
     result_ctx->host = dupstr(host);
@@ -3543,10 +3586,40 @@ int gtk_seat_verify_ssh_host_key(
     result_ctx->seat = seat;
 
     mainwin = GTK_WIDGET(gtk_seat_get_window(seat));
-    msgbox = create_message_box(
+    GtkWidget *more_info_button = NULL;
+    msgbox = create_message_box_general(
         mainwin, "PuTTY Security Alert", text,
         string_width(fingerprints[fptype_default]), true,
-        &buttons_hostkey, verify_ssh_host_key_result_callback, result_ctx);
+        &buttons_hostkey, verify_ssh_host_key_result_callback, result_ctx,
+        add_more_info_button, &more_info_button);
+
+    result_ctx->main_dialog = msgbox;
+    result_ctx->more_info_dialog = NULL;
+
+    strbuf *sb = strbuf_new();
+    if (fingerprints[SSH_FPTYPE_SHA256])
+        strbuf_catf(sb, "SHA256 fingerprint: %s\n",
+                    fingerprints[SSH_FPTYPE_SHA256]);
+    if (fingerprints[SSH_FPTYPE_MD5])
+        strbuf_catf(sb, "MD5 fingerprint: %s\n",
+                    fingerprints[SSH_FPTYPE_MD5]);
+    strbuf_catf(sb, "Full text of host's public key:");
+    /* We have to manually wrap the public key, or else the GtkLabel
+     * will resize itself to accommodate the longest word, which will
+     * lead to a hilariously wide message box. */
+    for (const char *p = keydisp, *q = p + strlen(p); p < q ;) {
+        size_t linelen = q-p;
+        if (linelen > 72)
+            linelen = 72;
+        put_byte(sb, '\n');
+        put_data(sb, p, linelen);
+        p += linelen;
+    }
+    result_ctx->more_info = strbuf_to_str(sb);
+
+    g_signal_connect(G_OBJECT(more_info_button), "clicked",
+                     G_CALLBACK(more_info_button_clicked), result_ctx);
+
     register_dialog(seat, DIALOG_SLOT_NETWORK_PROMPT, msgbox);
 
     sfree(text);

windows/win_res.h

@@ -15,6 +15,7 @@
 #define IDD_LICENCEBOX   113
 #define IDD_HK_ABSENT    114
 #define IDD_HK_WRONG     115
+#define IDD_HK_MOREINFO  116
 
 #define IDN_LIST        1001
 #define IDN_COPY        1002
@@ -36,6 +37,11 @@
 #define IDC_HK_ACCEPT   1001
 #define IDC_HK_ONCE     1000
 #define IDC_HK_FINGERPRINT 1002
+#define IDC_HK_MOREINFO 1003
+
+#define IDC_HKI_SHA256  1000
+#define IDC_HKI_MD5     1001
+#define IDC_HKI_PUBKEY  1002
 
 #define ID_CUSTOM_CHMFILE 2000
 #define TYPE_CUSTOM_CHMFILE 2000

windows/win_res.rc2

@@ -63,58 +63,75 @@ BEGIN
 END
 
 /* No accelerators used */
-IDD_HK_ABSENT DIALOG DISCARDABLE 50, 50, 300, 148
+IDD_HK_ABSENT DIALOG DISCARDABLE 50, 50, 340, 148
 STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
 CAPTION "PuTTY Security Alert"
 FONT 8, "MS Shell Dlg"
 BEGIN
-    LTEXT "The server's host key is not cached in the registry. You have no", 100, 40, 20, 260, 8
+    LTEXT "The server's host key is not cached in the registry. You have no", 100, 40, 20, 300, 8
-    LTEXT "guarantee that the server is the computer you think it is.", 101, 40, 28, 260, 8
+    LTEXT "guarantee that the server is the computer you think it is.", 101, 40, 28, 300, 8
-    LTEXT "The server's {KEYTYPE} key fingerprint is:", 102, 40, 40, 260, 8
+    LTEXT "The server's {KEYTYPE} key fingerprint is:", 102, 40, 40, 300, 8
-    LTEXT "If you trust this host, press ""Accept"" to add the key to {APPNAME}'s", 103, 40, 60, 260, 8
+    LTEXT "If you trust this host, press ""Accept"" to add the key to {APPNAME}'s", 103, 40, 60, 300, 8
-    LTEXT "cache and carry on connecting.", 104, 40, 68, 260, 8
+    LTEXT "cache and carry on connecting.", 104, 40, 68, 300, 8
-    LTEXT "If you want to carry on connecting just once, without adding the key", 105, 40, 80, 260, 8
+    LTEXT "If you want to carry on connecting just once, without adding the key", 105, 40, 80, 300, 8
-    LTEXT "to the cache, press ""Connect Once"".", 106, 40, 88, 260, 8
+    LTEXT "to the cache, press ""Connect Once"".", 106, 40, 88, 300, 8
-    LTEXT "If you do not trust this host, press ""Cancel"" to abandon the connection.", 107, 40, 100, 260, 8
+    LTEXT "If you do not trust this host, press ""Cancel"" to abandon the connection.", 107, 40, 100, 300, 8
 
     ICON "", IDC_HK_ICON, 10, 18, 0, 0
 
-    PUSHBUTTON "Cancel", IDCANCEL, 248, 128, 40, 14
+    PUSHBUTTON "Cancel", IDCANCEL, 288, 128, 40, 14
-    PUSHBUTTON "Accept", IDC_HK_ACCEPT, 128, 128, 40, 14
+    PUSHBUTTON "Accept", IDC_HK_ACCEPT, 168, 128, 40, 14
-    PUSHBUTTON "Connect Once", IDC_HK_ONCE, 176, 128, 64, 14
+    PUSHBUTTON "Connect Once", IDC_HK_ONCE, 216, 128, 64, 14
+    PUSHBUTTON "More info...", IDC_HK_MOREINFO, 60, 128, 64, 14
     PUSHBUTTON "Help", IDHELP, 12, 128, 40, 14
 
-    EDITTEXT IDC_HK_FINGERPRINT, 40, 48, 260, 12, ES_READONLY | ES_LEFT, 0
+    EDITTEXT IDC_HK_FINGERPRINT, 40, 48, 300, 12, ES_READONLY | ES_LEFT, 0
 END
 
 /* No accelerators used */
-IDD_HK_WRONG DIALOG DISCARDABLE 50, 50, 300, 188
+IDD_HK_WRONG DIALOG DISCARDABLE 50, 50, 340, 188
 STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
 CAPTION "PuTTY Security Alert"
 FONT 8, "MS Shell Dlg"
 BEGIN
-    LTEXT "WARNING - POTENTIAL SECURITY BREACH!", IDC_HK_TITLE, 40, 20, 260, 12
+    LTEXT "WARNING - POTENTIAL SECURITY BREACH!", IDC_HK_TITLE, 40, 20, 300, 12
 
-    LTEXT "The server's host key does not match the one {APPNAME} has cached in", 100, 40, 36, 260, 8
+    LTEXT "The server's host key does not match the one {APPNAME} has cached in", 100, 40, 36, 300, 8
-    LTEXT "the registry. This means that either the server administrator has", 101, 40, 44, 260, 8
+    LTEXT "the registry. This means that either the server administrator has", 101, 40, 44, 300, 8
-    LTEXT "changed the host key, or you have actually connected to another", 102, 40, 52, 260, 8
+    LTEXT "changed the host key, or you have actually connected to another", 102, 40, 52, 300, 8
-    LTEXT "computer pretending to be the server.", 103, 40, 60, 260, 8
+    LTEXT "computer pretending to be the server.", 103, 40, 60, 300, 8
-    LTEXT "The new {KEYTYPE} key fingerprint is:", 104, 40, 72, 260, 8
+    LTEXT "The new {KEYTYPE} key fingerprint is:", 104, 40, 72, 300, 8
-    LTEXT "If you were expecting this change and trust the new key, press", 105, 40, 92, 260, 8
+    LTEXT "If you were expecting this change and trust the new key, press", 105, 40, 92, 300, 8
-    LTEXT """Accept"" to update {APPNAME}'s cache and continue connecting.", 106, 40, 100, 260, 8
+    LTEXT """Accept"" to update {APPNAME}'s cache and continue connecting.", 106, 40, 100, 300, 8
-    LTEXT "If you want to carry on connecting but without updating the cache,", 107, 40, 112, 260, 8
+    LTEXT "If you want to carry on connecting but without updating the cache,", 107, 40, 112, 300, 8
-    LTEXT "press ""Connect Once"".", 108, 40, 120, 260, 8
+    LTEXT "press ""Connect Once"".", 108, 40, 120, 300, 8
-    LTEXT "If you want to abandon the connection completely, press ""Cancel"".", 109, 40, 132, 260, 8
+    LTEXT "If you want to abandon the connection completely, press ""Cancel"".", 109, 40, 132, 300, 8
-    LTEXT "Pressing ""Cancel"" is the ONLY guaranteed safe choice.", 110, 40, 140, 260, 8
+    LTEXT "Pressing ""Cancel"" is the ONLY guaranteed safe choice.", 110, 40, 140, 300, 8
 
     ICON "", IDC_HK_ICON, 10, 16, 0, 0
 
-    PUSHBUTTON "Cancel", IDCANCEL, 248, 168, 40, 14
+    PUSHBUTTON "Cancel", IDCANCEL, 288, 168, 40, 14
-    PUSHBUTTON "Accept", IDC_HK_ACCEPT, 128, 168, 40, 14
+    PUSHBUTTON "Accept", IDC_HK_ACCEPT, 168, 168, 40, 14
-    PUSHBUTTON "Connect Once", IDC_HK_ONCE, 176, 168, 64, 14
+    PUSHBUTTON "Connect Once", IDC_HK_ONCE, 216, 168, 64, 14
+    PUSHBUTTON "More info...", IDC_HK_MOREINFO, 60, 168, 64, 14
     PUSHBUTTON "Help", IDHELP, 12, 168, 40, 14
 
-    EDITTEXT IDC_HK_FINGERPRINT, 40, 80, 260, 12, ES_READONLY | ES_LEFT, 0
+    EDITTEXT IDC_HK_FINGERPRINT, 40, 80, 300, 12, ES_READONLY | ES_LEFT, 0
+END
+
+/* Accelerators used: clw */
+IDD_HK_MOREINFO DIALOG DISCARDABLE 140, 40, 400, 156
+STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
+CAPTION "PuTTY: information about the server's host key"
+FONT 8, "MS Shell Dlg"
+BEGIN
+    LTEXT "SHA256 fingerprint:", 100, 12, 12, 80, 8
+    EDITTEXT IDC_HKI_SHA256, 100, 10, 288, 12, ES_READONLY
+    LTEXT "MD5 fingerprint:", 101, 12, 28, 80, 8
+    EDITTEXT IDC_HKI_MD5, 100, 26, 288, 12, ES_READONLY
+    LTEXT "Full public key:", 102, 12, 44, 376, 8
+    EDITTEXT IDC_HKI_PUBKEY, 12, 54, 376, 64, ES_READONLY | ES_MULTILINE | ES_LEFT | ES_AUTOVSCROLL, WS_EX_STATICEDGE
+    DEFPUSHBUTTON "&Close", IDOK, 176, 130, 48, 14
 END
 
 #include "version.rc2"

windows/windlg.c

@@ -838,11 +838,47 @@ void showabout(HWND hwnd)
 struct hostkey_dialog_ctx {
     const char *const *keywords;
     const char *const *values;
-    const char *fingerprint;
+    FingerprintType fptype_default;
+    char **fingerprints;
+    const char *keydisp;
     LPCTSTR iconid;
     const char *helpctx;
 };
 
+static INT_PTR CALLBACK HostKeyMoreInfoProc(HWND hwnd, UINT msg,
+                                            WPARAM wParam, LPARAM lParam)
+{
+    switch (msg) {
+      case WM_INITDIALOG: {
+        const struct hostkey_dialog_ctx *ctx =
+            (const struct hostkey_dialog_ctx *)lParam;
+        SetWindowLongPtr(hwnd, GWLP_USERDATA, (INT_PTR)ctx);
+
+        if (ctx->fingerprints[SSH_FPTYPE_SHA256])
+            SetDlgItemText(hwnd, IDC_HKI_SHA256,
+                           ctx->fingerprints[SSH_FPTYPE_SHA256]);
+        if (ctx->fingerprints[SSH_FPTYPE_MD5])
+            SetDlgItemText(hwnd, IDC_HKI_MD5,
+                           ctx->fingerprints[SSH_FPTYPE_MD5]);
+
+        SetDlgItemText(hwnd, IDA_TEXT, ctx->keydisp);
+
+        return 1;
+      }
+      case WM_COMMAND:
+        switch (LOWORD(wParam)) {
+          case IDOK:
+            EndDialog(hwnd, 0);
+            return 0;
+        }
+        return 0;
+      case WM_CLOSE:
+        EndDialog(hwnd, 0);
+        return 0;
+    }
+    return 0;
+}
+
 static INT_PTR CALLBACK HostKeyDialogProc(HWND hwnd, UINT msg,
                                           WPARAM wParam, LPARAM lParam)
 {
@@ -878,7 +914,8 @@ static INT_PTR CALLBACK HostKeyDialogProc(HWND hwnd, UINT msg,
         }
         strbuf_free(sb);
 
-        SetDlgItemText(hwnd, IDC_HK_FINGERPRINT, ctx->fingerprint);
+        SetDlgItemText(hwnd, IDC_HK_FINGERPRINT,
+                       ctx->fingerprints[ctx->fptype_default]);
         MakeDlgItemBorderless(hwnd, IDC_HK_FINGERPRINT);
 
         HANDLE icon = LoadImage(
@@ -929,6 +966,13 @@ static INT_PTR CALLBACK HostKeyDialogProc(HWND hwnd, UINT msg,
             launch_help(hwnd, ctx->helpctx);
             return 0;
           }
+          case IDC_HK_MOREINFO: {
+            const struct hostkey_dialog_ctx *ctx =
+                (const struct hostkey_dialog_ctx *)
+                GetWindowLongPtr(hwnd, GWLP_USERDATA);
+            DialogBoxParam(hinst, MAKEINTRESOURCE(IDD_HK_MOREINFO),
+                           hwnd, HostKeyMoreInfoProc, (LPARAM)ctx);
+          }
         }
         return 0;
       case WM_CLOSE:
@@ -965,8 +1009,9 @@ int win_seat_verify_ssh_host_key(
         struct hostkey_dialog_ctx ctx[1];
         ctx->keywords = keywords;
         ctx->values = values;
-        ctx->fingerprint = fingerprints[
+        ctx->fingerprints = fingerprints;
-            ssh2_pick_default_fingerprint(fingerprints)];
+        ctx->fptype_default = ssh2_pick_default_fingerprint(fingerprints);
+        ctx->keydisp = keydisp;
         ctx->iconid = (ret == 2 ? IDI_WARNING : IDI_QUESTION);
         ctx->helpctx = (ret == 2 ? WINHELP_CTX_errors_hostkey_changed :
                         WINHELP_CTX_errors_hostkey_absent);