common: Use new function to print status strings.

* common/asshelp2.c (vprint_assuan_status_strings): New.
(print_assuan_status_strings): New.
* agent/command.c (agent_write_status): Replace by call to new
function.
* dirmngr/server.c (dirmngr_status): Ditto.
* g13/server.c (g13_status): Ditto.
* g13/sh-cmd.c (g13_status): Ditto.
* sm/server.c (gpgsm_status2): Ditto.
* scd/command.c (send_status_info): Bump up N.
--

This fixes a potential overflow if LFs are passed to the status
string functions.  This is actually not the case and would be wrong
because neither the truncating in libassuan or our escaping is not the
Right Thing.  In any case the functions need to be more robust and
comply to the promised interface.  Thus the code has been factored out
to a helper function and N has been bumped up correctly and checked in
all cases.

For some uses this changes the behaviour in the error case (i.e. CR or
LF passed): It will now always be C-escaped and not passed to
libassuan which would truncate the line at the first LF.

Reported-by: private_pers

2 files changed, 7 insertions, 42 deletions

diff --git a/g13/server.c b/g13/server.c
index bbe42d4f6..defde6c02 100644
--- a/g13/server.c
+++ b/g13/server.c
@@ -34,6 +34,7 @@
 #include "mount.h"
 #include "suspend.h"
 #include "../common/server-help.h"
+#include "../common/asshelp.h"
 #include "../common/call-gpg.h"
 
 
@@ -737,24 +738,8 @@ g13_status (ctrl_t ctrl, int no, ...)
     }
   else
     {
-      assuan_context_t ctx = ctrl->server_local->assuan_ctx;
-      char buf[950], *p;
-      size_t n;
-
-      p = buf;
-      n = 0;
-      while ( (text = va_arg (arg_ptr, const char *)) )
-        {
-          if (n)
-            {
-              *p++ = ' ';
-              n++;
-            }
-          for ( ; *text && n < DIM (buf)-2; n++)
-            *p++ = *text++;
-        }
-      *p = 0;
-      err = assuan_write_status (ctx, get_status_string (no), buf);
+      err = vprint_assuan_status_strings (ctrl->server_local->assuan_ctx,
+                                          get_status_string (no), arg_ptr);
     }
 
   va_end (arg_ptr);
diff --git a/g13/sh-cmd.c b/g13/sh-cmd.c
index b57369d9c..791e3b7f4 100644
--- a/g13/sh-cmd.c
+++ b/g13/sh-cmd.c
@@ -28,6 +28,7 @@
 #include "g13-syshelp.h"
 #include <assuan.h>
 #include "../common/i18n.h"
+#include "../common/asshelp.h"
 #include "keyblob.h"
 
 
@@ -904,34 +905,13 @@ sh_encrypt_keyblob (ctrl_t ctrl, const void *keyblob, size_t keybloblen,
 gpg_error_t
 g13_status (ctrl_t ctrl, int no, ...)
 {
-  gpg_error_t err = 0;
+  gpg_error_t err;
   va_list arg_ptr;
-  const char *text;
 
   va_start (arg_ptr, no);
 
-  if (1)
-    {
-      assuan_context_t ctx = ctrl->server_local->assuan_ctx;
-      char buf[950], *p;
-      size_t n;
-
-      p = buf;
-      n = 0;
-      while ( (text = va_arg (arg_ptr, const char *)) )
-        {
-          if (n)
-            {
-              *p++ = ' ';
-              n++;
-            }
-          for ( ; *text && n < DIM (buf)-2; n++)
-            *p++ = *text++;
-        }
-      *p = 0;
-      err = assuan_write_status (ctx, get_status_string (no), buf);
-    }
-
+  err = vprint_assuan_status_strings (ctrl->server_local->assuan_ctx,
+                                      get_status_string (no), arg_ptr);
   va_end (arg_ptr);
   return err;
 }