ssh: Add support for Putty.

* agent/gpg-agent.c [W32]: Include Several Windows header.
(opts): Change help text for enable-ssh-support.
(opts, main): Add option --enable-putty-support
(putty_support, PUTTY_IPC_MAGIC, PUTTY_IPC_MAXLEN): New for W32.
(agent_init_default_ctrl): Add and asssert call.
(putty_message_proc, putty_message_thread): New.
(handle_connections) [W32]: Start putty message thread.
* common/sysutils.c (w32_get_user_sid): New for W32 only
* tools/gpgconf-comp.c (gc_options_gpg_agent): Add
--enable-ssh-support and --enable-putty-support.  Make the
configuration group visible at basic level.
* agent/command-ssh.c (serve_mmapped_ssh_request): New for W32 only.
--

This patch enables support for Putty.  It has been tested with Putty
0.62 using an Unix created ssh key copied to the private-keys-v1.d
directory on Windows and with a manually crafted sshcontrol file.  It
also works with a smartcard key.

May thanks to gniibe who implemented a proxy in Python to test the
putty/gpg-agent communication.

Signed-off-by: Werner Koch <[email protected]>
(cherry picked from commit 9f32499f99a0817f63f7a73b09bdcebe60d4775d)

Resolved conflicts:
	NEWS
	agent/agent.h
	agent/gpg-agent.c: Convert from pth to npth.
	common/sysutils.c
	common/sysutils.h

1 files changed, 8 insertions, 3 deletions

diff --git a/agent/agent.h b/agent/agent.h
index d40930018..eac7ba548 100644
--- a/agent/agent.h
+++ b/agent/agent.h
@@ -289,9 +289,14 @@ gpg_error_t agent_print_status (ctrl_t ctrl, const char *keyword,
 void bump_key_eventcounter (void);
 void bump_card_eventcounter (void);
 void start_command_handler (ctrl_t, gnupg_fd_t, gnupg_fd_t);
-gpg_error_t pinentry_loopback(ctrl_t, const char *keyword,
-	                      unsigned char **buffer, size_t *size,
-			      size_t max_length);
+gpg_error_t pinentry_loopback (ctrl_t, const char *keyword,
+	                       unsigned char **buffer, size_t *size,
+			       size_t max_length);
+
+#ifdef HAVE_W32_SYSTEM
+int serve_mmapped_ssh_request (ctrl_t ctrl,
+                               unsigned char *request, size_t maxreqlen);
+#endif /*HAVE_W32_SYSTEM*/
 
 /*-- command-ssh.c --*/
 ssh_control_file_t ssh_open_control_file (void);