From: Jan Tojnar Date: Thu, 18 May 2023 14:30:35 +0000 (+0200) Subject: Add gnome-ssh-askpass4 for GNOME 40+ X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=e6805e2a6b33e001e1a7257b85ab779fd592a578;p=thirdparty%2Fopenssh-portable.git Add gnome-ssh-askpass4 for GNOME 40+ GTK 3 has been in maintenance mode for a while now, and it is on the road to being abandoned. As a result, the dialogue looks out of place on modern systems. We could port it to GTK 4 but without the program being registered as an application (i.e. having a .desktop file), GNOME Shell would ask for permission to grab input every time. Let’s instead use the GNOME Shell’s native prompt through the unstable Gcr API. --- diff --git a/contrib/Makefile b/contrib/Makefile index 45d878bdc..1482783a8 100644 --- a/contrib/Makefile +++ b/contrib/Makefile @@ -1,7 +1,7 @@ PKG_CONFIG = pkg-config all: - @echo "Valid targets: gnome-ssh-askpass1 gnome-ssh-askpass2 gnome-ssk-askpass3" + @echo "Valid targets: gnome-ssh-askpass1 gnome-ssh-askpass2 gnome-ssk-askpass3 gnome-ssh-askpass4" gnome-ssh-askpass1: gnome-ssh-askpass1.c $(CC) $(CFLAGS) `gnome-config --cflags gnome gnomeui` \ @@ -18,5 +18,10 @@ gnome-ssh-askpass3: gnome-ssh-askpass3.c gnome-ssh-askpass3.c -o gnome-ssh-askpass3 \ `$(PKG_CONFIG) --libs gtk+-3.0 x11` +gnome-ssh-askpass4: gnome-ssh-askpass4.c + $(CC) $(CFLAGS) `$(PKG_CONFIG) --cflags gcr-4 gio-2.0` \ + gnome-ssh-askpass4.c -o gnome-ssh-askpass4 \ + `$(PKG_CONFIG) --libs gcr-4 gio-2.0` + clean: rm -f *.o gnome-ssh-askpass gnome-ssh-askpass[123] diff --git a/contrib/README b/contrib/README index 60e19ba9f..614152a12 100644 --- a/contrib/README +++ b/contrib/README @@ -30,10 +30,12 @@ ssh-copy-id: Phil Hands' shell script to automate the process of adding your public key to a remote machine's ~/.ssh/authorized_keys file. -gnome-ssh-askpass[12]: +gnome-ssh-askpass[1234]: -A GNOME and Gtk2 passphrase requesters. Use "make gnome-ssh-askpass1" or -"make gnome-ssh-askpass2" to build. +Graphical passhrase requesters. Use "make gnome-ssh-askpass1" to build +a variant for ancient GNOME desktop, "make gnome-ssh-askpass2" +for a GTK 2-based one, "make gnome-ssh-askpass3" for a GTK 3-based one, +or "make gnome-ssh-askpass4" for a version for modern GNOME. sshd.pam.generic: diff --git a/contrib/gnome-ssh-askpass4.c b/contrib/gnome-ssh-askpass4.c new file mode 100644 index 000000000..182bce0cc --- /dev/null +++ b/contrib/gnome-ssh-askpass4.c @@ -0,0 +1,249 @@ +/* + * Copyright (c) 2000-2002 Damien Miller. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* GCR support by Jan Tojnar */ + +/* + * This is a simple SSH passphrase grabber for GNOME. To use it, set the + * environment variable SSH_ASKPASS to point to the location of + * gnome-ssh-askpass before calling "ssh-add < /dev/null". + */ + +/* + * Known problems: + * - This depends on unstable libgcr features + * - long key fingerprints may be truncted: + * https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/6781 + */ + +/* + * Compile with: + * + * cc -Wall `pkg-config --cflags gcr-4 gio-2.0` \ + * gnome-ssh-askpass4.c -o gnome-ssh-askpass \ + * `pkg-config --libs gcr-4 gio-2.0` + * + */ + +#include +#include + +#include + +#define GCR_API_SUBJECT_TO_CHANGE 1 +#include + +typedef enum _PromptType { + PROMPT_ENTRY, + PROMPT_CONFIRM, + PROMPT_NONE, +} PromptType; + +typedef struct _PromptState { + GApplication *app; + char* message; + PromptType type; + int exit_status; +} PromptState; + +static PromptState * +prompt_state_new(GApplication *app, char* message, PromptType type) +{ + PromptState *state = g_malloc(sizeof(PromptState)); + state->app = g_object_ref(app); + state->message = g_strdup(message); + state->type = type; + state->exit_status = -1; + return state; +} + +static void +prompt_state_free(PromptState *state) +{ + g_clear_object(&state->app); + g_free(state->message); + g_free(state); +} + +G_DEFINE_AUTOPTR_CLEANUP_FUNC(PromptState, prompt_state_free) + +static void +prompt_password_done(GObject *source_object, GAsyncResult *res, + gpointer user_data) +{ + GcrPrompt *prompt = GCR_PROMPT(source_object); + PromptState *state = user_data; + g_autoptr(GError) error = NULL; + + /* + * “The returned password is valid until the next time a method + * is called to display another prompt.” + */ + const char *pw = gcr_prompt_password_finish(prompt, res, &error); + + if ((!pw && !error) || (error && error->code == G_IO_ERROR_CANCELLED)) { + /* Operation was cancelled or timed out. */ + state->exit_status = -1; + } else if (error) { + warnx("Failed to prompt for ssh-askpass: %s", error->message); + state->exit_status = 1; + } else { + /* Report passphrase if user selected Continue. */ + g_autofree char *local = g_locale_from_utf8(pw, strlen(pw), + NULL, NULL, NULL); + + if (local != NULL) { + puts(local); + memset(local, '\0', strlen(local)); + } else { + puts(pw); + } + state->exit_status = 0; + } + + g_application_release(state->app); +} + +static void +prompt_confirm_done(GObject *source_object, GAsyncResult *res, + gpointer user_data) +{ + GcrPrompt *prompt = GCR_PROMPT(source_object); + PromptState *state = user_data; + g_autoptr(GError) error = NULL; + + GcrPromptReply reply = gcr_prompt_confirm_finish(prompt, res, &error); + if (error) { + if (error->code == G_IO_ERROR_CANCELLED) { + /* Operation was cancelled or timed out. */ + state->exit_status = -1; + } else { + state->exit_status = 1; + warnx("Failed to prompt for ssh-askpass: %s", + error->message); + } + } else if (reply == GCR_PROMPT_REPLY_CONTINUE || + state->type == PROMPT_NONE) { + /* + * Since Gcr doesn’t yet support one button message + * boxes treat Cancel the same as Continue. + */ + state->exit_status = 0; + } else { + /* GCR_PROMPT_REPLY_CANCEL */ + state->exit_status = -1; + } + + g_application_release(state->app); +} + +static int +command_line(GApplication* app, G_GNUC_UNUSED GApplicationCommandLine *cmdline, + gpointer user_data) +{ + PromptState *state = user_data; + + /* Prevent app from exiting while waiting for the async callback. */ + g_application_hold(app); + + /* Wait indefinitely. */ + int timeout_seconds = -1; + g_autoptr(GError) error = NULL; + GcrPrompt* prompt = gcr_system_prompt_open(timeout_seconds, NULL, &error); + + if (!prompt) { + if (error->code == GCR_SYSTEM_PROMPT_IN_PROGRESS) { + /* + * This means the timeout elapsed, but no prompt + * was ever shown. + */ + warnx("Timeout: the Gcr system prompter was " + "already in use."); + } else { + warnx("Couldn’t create prompt for ssh-askpass: %s", + error->message); + } + + return 1; + } + + gcr_prompt_set_message(prompt, "OpenSSH"); + gcr_prompt_set_description(prompt, state->message); + + /* + * XXX: Remove the Cancel button for PROMPT_NONE when GCR + * supports that. + */ + if (state->type == PROMPT_ENTRY) { + gcr_prompt_password_async(prompt, NULL, prompt_password_done, state); + } else { + gcr_prompt_confirm_async(prompt, NULL, prompt_confirm_done, state); + } + + /* The exit status will be changed in the async callbacks. */ + return 1; +} + +int +main(int argc, char **argv) +{ + g_autoptr(GApplication) app = g_application_new( + "com.openssh.gnome-ssh-askpass4", + G_APPLICATION_HANDLES_COMMAND_LINE); + g_autofree char *message = NULL; + + if (argc > 1) { + message = g_strjoinv(" ", argv + 1); + } else { + message = g_strdup("Enter your OpenSSH passphrase:"); + } + + const char *prompt_mode = getenv("SSH_ASKPASS_PROMPT"); + PromptType type = PROMPT_ENTRY; + if (prompt_mode != NULL) { + if (strcasecmp(prompt_mode, "confirm") == 0) { + type = PROMPT_CONFIRM; + } else if (strcasecmp(prompt_mode, "none") == 0) { + type = PROMPT_NONE; + } + } + + g_autoptr(PromptState) state = prompt_state_new(app, message, type); + + g_signal_connect(app, "command-line", G_CALLBACK(command_line), state); + + /* + * Since we are calling g_application_hold, we cannot use + * g_application_command_line_set_exit_status. + * To change the exit status returned by g_application_run: + * “If the commandline invocation results in the mainloop running + * (ie: because the use-count of the application increased to a + * non-zero value) then the application is considered to have been + * ‘successful’ in a certain sense, and the exit status is always + * zero.” + */ + (void)(g_application_run(app, argc, argv)); + + return state->exit_status; +}