# could an environment variable (if set) override the current time, to
# be able to create a standard key? If we read the key from a file
# instead of stdin, should we use the creation time on the file?
-my $timestamp = time();
+my $timestamp = $ENV{PEM2OPENPGP_TIMESTAMP};
+if (! defined $timestamp)
+ $timestamp = time();
+
+my $flags = 0;
+if (! defined $ENV{PEM2OPENPGP_USAGE_FLAGS})
+ $flags = $usage_flags->{authenticate};
+else {
+ my @ff = split(",", $ENV{PEM2OPENPGP_USAGE_FLAGS});
+ foreach $f (@ff) {
+ if (! defined $usage_flags->{$f})
+ die "No such flag $f";
+ $flags |= $usage_flags->{$f};
+ }
+}
my $creation_time_packet = pack('CCN', 5, $subpacket_types->{sig_creation_time}, $timestamp);