From 3daeef702b2e6a42f0f396b828f86ffc3f33fc88 Mon Sep 17 00:00:00 2001
From: Damien Goutte-Gattat <dgouttegattat@incenp.org>
Date: Wed, 18 Jan 2017 18:52:12 +0100
Subject: [PATCH] gpg: Allow to freeze faked system time.

* g10/gpg.c (main): If the parameter for --faked-system-time
ends with a '!', freeze time at the specified point.
* common/gettime.c (gnupg_set_time): Allow to freeze the time
at an arbitrary time instead of only the current time.
* doc/gpg.texi: Update documentation for --faked-system-time.
--

This patch allows the user to modify the behavior of the
--faked-system-time option: by appending a '!' to the parameter,
time in GnuPG will be frozen at the specified time, instead of
advancing normally from that time onward.

Signed-off-by: Damien Goutte-Gattat <dgouttegattat@incenp.org>
---
 common/gettime.c |  2 +-
 doc/gpg.texi     |  3 +++
 g10/gpg.c        | 14 ++++++++++++--
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/common/gettime.c b/common/gettime.c
index e5da4fb1a..3e1ee5569 100644
--- a/common/gettime.c
+++ b/common/gettime.c
@@ -133,7 +133,7 @@ gnupg_set_time (time_t newtime, int freeze)
   else if (freeze)
     {
       timemode = FROZEN;
-      timewarp = current;
+      timewarp = newtime == (time_t)-1 ? current : newtime;
     }
   else if (newtime > current)
     {
diff --git a/doc/gpg.texi b/doc/gpg.texi
index 4ea2cd21e..044ba3761 100644
--- a/doc/gpg.texi
+++ b/doc/gpg.texi
@@ -2748,6 +2748,9 @@ forth to @var{epoch} which is the number of seconds elapsed since the year
 1970.  Alternatively @var{epoch} may be given as a full ISO time string
 (e.g. "20070924T154812").
 
+If you suffix @var{epoch} with an exclamation mark (!), the system time
+will appear to be frozen at the specified time.
+
 @item --enable-progress-filter
 @opindex enable-progress-filter
 Enable certain PROGRESS status outputs. This option allows frontends
diff --git a/g10/gpg.c b/g10/gpg.c
index 8c5b50589..f9039ae09 100644
--- a/g10/gpg.c
+++ b/g10/gpg.c
@@ -3493,10 +3493,20 @@ main (int argc, char **argv)
 
           case oFakedSystemTime:
             {
-              time_t faked_time = isotime2epoch (pargs.r.ret_str);
+              size_t len = strlen (pargs.r.ret_str);
+              int freeze = 0;
+              time_t faked_time;
+
+              if (len > 0 && pargs.r.ret_str[len-1] == '!')
+                {
+                  freeze = 1;
+                  pargs.r.ret_str[len-1] = '\0';
+                }
+
+              faked_time = isotime2epoch (pargs.r.ret_str);
               if (faked_time == (time_t)(-1))
                 faked_time = (time_t)strtoul (pargs.r.ret_str, NULL, 10);
-              gnupg_set_time (faked_time, 0);
+              gnupg_set_time (faked_time, freeze);
             }
             break;