Extend ACL-restriction to all Windows tools.

Protecting our processes from outside interference need not be limited
to just PuTTY: there's no reason why the other SSH-speaking tools
shouldn't have the same treatment (PSFTP, PSCP, Plink), and PuTTYgen
and Pageant which handle private key material.

Recipe

@@ -296,7 +296,7 @@ puttygen : [G] winpgen sshrsag sshdssg sshprime sshdes sshbn sshmd5 version
          + sshrand winnoise sshsha winstore misc winctrls sshrsa sshdss winmisc
          + sshpubk sshaes sshsh256 sshsh512 IMPORT winutils puttygen.res
          + tree234 notiming winhelp winnojmp conf LIBS wintime sshecc
-         + sshecdsag
+         + sshecdsag winsecur
 
 pterm    : [X] GTKTERM uxmisc misc ldisc settings uxpty uxsel BE_NONE uxstore
          + uxsignal CHARSET cmdline uxpterm version time xpmpterm xpmptcfg

pscp.c

@@ -2349,6 +2349,8 @@ int psftp_main(int argc, char *argv[])
     argv += i;
     back = NULL;
 
+    platform_psftp_post_option_setup();
+
     if (list) {
 	if (argc != 1)
 	    usage();

psftp.c

@@ -2941,6 +2941,8 @@ int psftp_main(int argc, char *argv[])
     argv += i;
     back = NULL;
 
+    platform_psftp_post_option_setup();
+
     /*
      * If the loaded session provides a hostname, and a hostname has not
      * otherwise been specified, pop it in `userhost' so that

psftp.h

@@ -47,6 +47,13 @@ int ssh_sftp_loop_iteration(void);
  */
 char *ssh_sftp_get_cmdline(const char *prompt, int backend_required);
 
+/*
+ * Platform-specific function called after the command line has been
+ * processed, so that any per-platform initialisation such as process
+ * ACL setup can be done.
+ */
+void platform_psftp_post_option_setup(void);
+
 /*
  * The main program in psftp.c. Called from main() in the platform-
  * specific code, after doing any platform-specific initialisation.

unix/uxsftp.c

@@ -618,6 +618,8 @@ char *ssh_sftp_get_cmdline(const char *prompt, int no_fds_ok)
 
 void frontend_net_error_pending(void) {}
 
+void platform_psftp_post_option_setup(void) {}
+
 /*
  * Main program: do platform-specific initialisation and then call
  * psftp_main().

windows/winpgen.c

@@ -12,6 +12,7 @@
 #include "putty.h"
 #include "ssh.h"
 #include "licence.h"
+#include "winsecur.h"
 
 #include <commctrl.h>
 
@@ -1530,6 +1531,23 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 	}
     }
 
+#ifndef UNPROTECT
+    /*
+     * Protect our process.
+     */
+    {
+        char *error = NULL;
+        if (!setprocessacl(error)) {
+            char *message = dupprintf("Could not restrict process ACL: %s",
+                                      error);
+            MessageBox(NULL, message, "PuTTYgen Warning",
+                       MB_ICONWARNING | MB_OK);
+            sfree(message);
+            sfree(error);
+        }
+    }
+#endif
+
     random_ref();
     ret = DialogBox(hinst, MAKEINTRESOURCE(201), NULL, MainDlgProc) != IDOK;
 

windows/winpgnt.c

@@ -1174,6 +1174,23 @@ int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 	}
     }
 
+#ifndef UNPROTECT
+    /*
+     * Protect our process.
+     */
+    {
+        char *error = NULL;
+        if (!setprocessacl(error)) {
+            char *message = dupprintf("Could not restrict process ACL: %s",
+                                      error);
+            MessageBox(NULL, message, "Pageant Warning",
+                       MB_ICONWARNING | MB_OK);
+            sfree(message);
+            sfree(error);
+        }
+    }
+#endif
+
     /*
      * Forget any passphrase that we retained while going over
      * command line keyfiles.

windows/winplink.c

@@ -11,6 +11,7 @@
 #include "putty.h"
 #include "storage.h"
 #include "tree234.h"
+#include "winsecur.h"
 
 #define WM_AGENT_CALLBACK (WM_APP + 4)
 
@@ -497,6 +498,22 @@ int main(int argc, char **argv)
 	}
     }
 
+#ifndef UNPROTECT
+    /*
+     * Protect our process.
+     */
+    {
+        char *error = NULL;
+        if (!setprocessacl(error)) {
+            char *message = dupprintf("Could not restrict process ACL: %s",
+                                      error);
+            logevent(NULL, message);
+            sfree(message);
+            sfree(error);
+        }
+    }
+#endif
+
     if (errors)
 	return 1;
 

windows/winsftp.c

@@ -733,6 +733,25 @@ char *ssh_sftp_get_cmdline(const char *prompt, int no_fds_ok)
     return ctx->line;
 }
 
+void platform_psftp_post_option_setup(void)
+{
+#ifndef UNPROTECT
+    /*
+     * Protect our process.
+     */
+    {
+        char *error = NULL;
+        if (!setprocessacl(error)) {
+            char *message = dupprintf("Could not restrict process ACL: %s",
+                                      error);
+            logevent(NULL, message);
+            sfree(message);
+            sfree(error);
+        }
+    }
+#endif
+}
+
 /* ----------------------------------------------------------------------
  * Main program. Parse arguments etc.
  */