Add an API to change passphrases. Currently only implemented for

GPGSM.  Requires GnuPG 2.1

NEWS

@@ -1,4 +1,4 @@
-Noteworthy changes in version 1.2.1 (unreleased)
+Noteworthy changes in version 1.3.0 (unreleased)
 ------------------------------------------------
 
  * GPGME does not come with an internal libassuan version anymore.
@@ -10,14 +10,21 @@ Noteworthy changes in version 1.2.1 (unreleased)
 
  * New engine GPGME_PROTOCOL_UISERVER to support UI Servers.
 
+ * New API to change the passpgrase of a key.
+
  * Interface changes relative to the 1.2.0 release:
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-GPGME_STATUS_INV_SGNR    NEW
+ GPGME_STATUS_INV_SGNR    NEW.
-GPGME_STATUS_NO_SGNR     NEW
+ GPGME_STATUS_NO_SGNR     NEW.
-GPGME_PROTOCOL_G13	 NEW
+ GPGME_PROTOCOL_G13	  NEW.
-gpgme_op_g13_mount	 NEW
+ gpgme_op_g13_mount	  NEW.
-gpgme_g13_result_t	 NEW
+ gpgme_g13_result_t	  NEW.
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ GPGME_PK_ECDSA           NEW.
+ GPGME_PK_ECDH            NEW.
+ gpgme_op_passwd_start    NEW.
+ gpgme_op_passwd          NEW.
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 
 Noteworthy changes in version 1.2.0 (2009-06-18)
 ------------------------------------------------
@@ -1321,7 +1328,8 @@ Noteworthy changes in version 0.2.1 (2001-04-02)
  * Made the W32 support more robust.
 
 
- Copyright 2001, 2002, 2003, 2004, 2005, 2007, 2008 g10 Code GmbH
+ Copyright 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009,
+           2010 g10 Code GmbH
 
  This file is free software; as a special exception the author gives
  unlimited permission to copy and/or distribute it, with or without

README

@@ -1,7 +1,7 @@
                   GPGME - GnuPG Made Easy
                 ---------------------------
 
-               Copyright 2004, 2006 g10 Code GmbH
+               Copyright 2004, 2006, 2010 g10 Code GmbH
 
 This file is free software; as a special exception the author gives
 unlimited permission to copy and/or distribute it, with or without

configure.ac

@@ -1,6 +1,7 @@
 # configure.ac for GPGME
 # Copyright (C) 2000 Werner Koch (dd9jn)
-# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 g10 Code GmbH
+# Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
+#               2009, 2010  g10 Code GmbH
 # 
 # This file is part of GPGME.
 # 
@@ -31,7 +32,7 @@ min_automake_version="1.10"
 # specific feature can already be done under the assumption that the
 # SVN version is the most recent one in a branch.  To disable the SVN
 # version for the real release, set the my_issvn macro to no.
-m4_define(my_version, [1.2.1])
+m4_define(my_version, [1.3.0])
 m4_define(my_issvn, [yes])
 
 m4_define([svn_revision], m4_esyscmd([printf "%d" $( (svn info 2>/dev/null \

doc/ChangeLog

@@ -1,3 +1,7 @@
+2010-01-05  Werner Koch  <wk@g10code.com>
+
+	* gpgme.texi (Changing Passphrases): New.
+
 2009-07-21  Werner Koch  <wk@g10code.com>
 
 	* uiserver.texi (UI Server Encrypt): Add --expect-sign option to

doc/gpgme.texi

@@ -13,7 +13,8 @@
 @syncodeindex pg fn
 
 @copying
-Copyright @copyright{} 2002, 2003, 2004, 2005, 2006, 2007, 2008 g10 Code GmbH.
+Copyright @copyright{} 2002, 2003, 2004, 2005, 2006, 2007,
+2008, 2010 g10 Code GmbH.
 
 @quotation
 Permission is granted to copy, distribute and/or modify this document
@@ -1014,6 +1015,18 @@ This value indicates ElGamal.
 
 @item GPGME_PK_ELG_E
 This value also indicates ElGamal and is used specifically in GnuPG.
+
+@item GPGME_PK_ELG_E
+This value also indicates ElGamal and is used specifically in GnuPG.
+
+@item GPGME_PK_ECDSA
+This value indicates ECDSA, the Elliptic Curve Digital Signature
+Algorithm as defined by FIPS 186-2.
+
+@item GPGME_PK_ECDH
+This value indicates ECDH, the Eliptic Curve Diffie-Hellmann encryption
+algorithm as defined by the ECC in OpenPGP draft.
+
 @end table
 @end deftp
 
@@ -2737,6 +2750,7 @@ in the list is the main (or primary) user ID.
 * Exporting Keys::                Retrieving key data from the key ring.
 * Importing Keys::                Adding keys to the key ring.
 * Deleting Keys::                 Removing keys from the key ring.
+* Changing Passphrases::          Change the passphrase of a key.
 * Advanced Key Editing::          Advanced key edit operation.
 @end menu
 
@@ -3715,6 +3729,38 @@ operation was started successfully, and @code{GPG_ERR_INV_VALUE} if
 @end deftypefun
 
 
+@node Changing Passphrases
+@subsection  Changing Passphrases
+@cindex passphrase, change
+
+@deftypefun gpgme_error_t gpgme_op_passwd      @
+             (@w{gpgme_ctx_t @var{ctx}},       @
+              @w{const gpgme_key_t @var{key}}, @
+              @w{unsigned int @var{flags}})
+
+The function @code{gpgme_op_passwd} changes the passphrase of the
+private key associated with @var{key}.  The only allowed value for
+@var{flags} is @code{0}.  The backend engine will usually popup a window
+to ask for the old and the new passphrase.  Thus this function is not
+useful in a server application (where passphrases are not required
+anyway).
+@end deftypefun
+
+@deftypefun gpgme_error_t gpgme_op_passwd_start      @
+             (@w{gpgme_ctx_t @var{ctx}},       @
+              @w{const gpgme_key_t @var{key}}, @
+              @w{unsigned int @var{flags}})
+
+The function @code{gpgme_op_passwd_start} initiates a
+@code{gpgme_op_passwd} operation.    It can be completed by calling
+@code{gpgme_wait} on the context.  @xref{Waiting For Completion}.
+
+The function returns @code{0} if the operation was started successfully,
+and an error code if one of the arguments is not valid or the oepration
+could not be started.
+@end deftypefun
+
+
 @node Advanced Key Editing
 @subsection Advanced Key Editing
 @cindex key, edit

src/ChangeLog

@@ -1,3 +1,21 @@
+2010-01-05  Werner Koch  <wk@g10code.com>
+
+	* gpgme-tool.c (gt_passwd, cmd_passwd): New.
+	(register_commands): Register.
+
+	* gpgme.h.in (gpgme_op_passwd_start, gpgme_op_passwd): New.
+	* libgpgme.vers, gpgme.def: Add new functions.
+	* passwd.c: New.
+	* Makefile.am (main_sources): Add passwd.c
+	* engine.c, engine.h (_gpgme_engine_op_passwd): New.
+	* engine-backend.h (struct engine_ops): Add PASSWD.
+	* engine-gpgsm.c (gpgsm_passwd): New.
+	(_gpgme_engine_ops_gpgsm): Register.
+	(gpgsm_reset): Reset only if we have a conenction.
+
+	* gpgme.h.in (GPGME_PK_ECDSA, GPGME_PK_ECDH): New.
+	* gpgme.c (gpgme_pubkey_algo_name): Add them.
+
 2009-12-22  Marcus Brinkmann  <marcus@g10code.de>
 
 	* debug.c: Test for TLS, not __GNUC__

src/Makefile.am

@@ -115,7 +115,7 @@ main_sources =								\
 	sign.c passphrase.c progress.c					\
 	key.c keylist.c trust-item.c trustlist.c			\
 	import.c export.c genkey.c delete.c edit.c getauditlog.c        \
-	opassuan.c                                                      \
+	opassuan.c passwd.c                                             \
 	engine.h engine-backend.h engine.c engine-gpg.c status-table.h	\
 	$(gpgsm_components) $(assuan_components) $(gpgconf_components)  \
 	$(uiserver_components)						\

src/engine-backend.h

@@ -118,6 +118,9 @@ struct engine_ops
 
   /* Cancel only the current operation, not the whole session.  */
   gpgme_error_t (*cancel_op) (void *engine);
+
+  /* Change the passphrase for KEY. */
+  gpgme_error_t (*passwd) (void *engine, gpgme_key_t key, unsigned int flags);
 };
 
 

src/engine-gpgsm.c

@@ -1,6 +1,7 @@
 /* engine-gpgsm.c - GpgSM engine.
    Copyright (C) 2000 Werner Koch (dd9jn)
-   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2009 g10 Code GmbH
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2009,
+                 2010 g10 Code GmbH
  
    This file is part of GPGME.
 
@@ -1053,13 +1054,18 @@ gpgsm_reset (void *engine)
 {
   engine_gpgsm_t gpgsm = engine;
 
-  /* We must send a reset because we need to reset the list of
+  /* IF we have an active connection we must send a reset because we
-     signers.  Note that RESET does not reset OPTION commands. */
+     need to reset the list of signers.  Note that RESET does not
-  return gpgsm_assuan_simple_command (gpgsm->assuan_ctx, "RESET", NULL, NULL);
+     reset OPTION commands. */
+  return (gpgsm->assuan_ctx
+          ? gpgsm_assuan_simple_command (gpgsm->assuan_ctx, "RESET",
+                                         NULL, NULL)
+          : 0);
 }
 #endif
 
 
+
 static gpgme_error_t
 gpgsm_decrypt (void *engine, gpgme_data_t ciph, gpgme_data_t plain)
 {
@@ -1894,6 +1900,32 @@ gpgsm_io_event (void *engine, gpgme_event_io_t type, void *type_data)
 }
 
 
+static gpgme_error_t
+gpgsm_passwd (void *engine, gpgme_key_t key, unsigned int flags)
+{
+  engine_gpgsm_t gpgsm = engine;
+  gpgme_error_t err;
+  char *line;
+
+  if (!key || !key->subkeys || !key->subkeys->fpr)
+    return gpg_error (GPG_ERR_INV_VALUE);
+
+  if (asprintf (&line, "PASSWD -- %s", key->subkeys->fpr) < 0)
+    return gpg_error_from_syserror ();
+  
+  gpgsm_clear_fd (gpgsm, OUTPUT_FD);
+  gpgsm_clear_fd (gpgsm, INPUT_FD);
+  gpgsm_clear_fd (gpgsm, MESSAGE_FD);
+  gpgsm->inline_data = NULL;
+
+  err = start (gpgsm, line);
+  free (line);
+
+  return err;
+}
+
+
+
 struct engine_ops _gpgme_engine_ops_gpgsm =
   {
     /* Static functions.  */
@@ -1937,5 +1969,6 @@ struct engine_ops _gpgme_engine_ops_gpgsm =
     gpgsm_set_io_cbs,
     gpgsm_io_event,
     gpgsm_cancel,
-    NULL		/* cancel_op */
+    NULL,		/* cancel_op */
+    gpgsm_passwd
   };

src/engine.c

@@ -1,6 +1,6 @@
 /* engine.c - GPGME engine support.
    Copyright (C) 2000 Werner Koch (dd9jn)
-   Copyright (C) 2001, 2002, 2003, 2004, 2006, 2009 g10 Code GmbH
+   Copyright (C) 2001, 2002, 2003, 2004, 2006, 2009, 2010 g10 Code GmbH
  
    This file is part of GPGME.
  
@@ -906,3 +906,19 @@ _gpgme_engine_cancel_op (engine_t engine)
 
   return (*engine->ops->cancel_op) (engine->engine);
 }
+
+
+/* Change the passphrase for KEY.  */
+gpgme_error_t
+_gpgme_engine_op_passwd (engine_t engine, gpgme_key_t key,
+                         unsigned int flags)
+{
+  if (!engine)
+    return gpg_error (GPG_ERR_INV_VALUE);
+
+  if (!engine->ops->passwd)
+    return gpg_error (GPG_ERR_NOT_IMPLEMENTED);
+
+  return (*engine->ops->passwd) (engine->engine, key, flags);
+}
+

src/engine.h

@@ -1,6 +1,6 @@
 /* engine.h - GPGME engine interface.
    Copyright (C) 2000 Werner Koch (dd9jn)
-   Copyright (C) 2001, 2002, 2003, 2004 g10 Code GmbH
+   Copyright (C) 2001, 2002, 2003, 2004, 2010 g10 Code GmbH
  
    This file is part of GPGME.
  
@@ -157,4 +157,8 @@ gpgme_error_t _gpgme_engine_cancel (engine_t engine);
 
 gpgme_error_t _gpgme_engine_cancel_op (engine_t engine);
 
+gpgme_error_t _gpgme_engine_op_passwd (engine_t engine, gpgme_key_t key,
+                                       unsigned int flags);
+
+
 #endif /* ENGINE_H */

src/gpgme-tool.c

@@ -1,6 +1,5 @@
 /* gpgme-tool.c - GnuPG Made Easy.
-   Copyright (C) 2000 Werner Koch (dd9jn)
+   Copyright (C) 2009, 2010 g10 Code GmbH
-   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007 g10 Code GmbH
 
    This file is part of GPGME.
  
@@ -15,9 +14,8 @@
    Lesser General Public License for more details.
    
    You should have received a copy of the GNU Lesser General Public
-   License along with this program; if not, write to the Free Software
+   License along with this program; if not, see <http://www.gnu.org/licenses/>.
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ */
-   02111-1307, USA.  */
 
 #if HAVE_CONFIG_H
 #include <config.h>
@@ -1119,7 +1117,30 @@ gt_vfs_create (gpgme_tool_t gt, const char *container_file, int flags)
 }
 
 
-// TODO
+static const char hlp_passwd[] = 
+  "PASSWD <user-id>\n"
+  "\n"
+  "Ask the backend to change the passphrase for the key\n"
+  "specified by USER-ID.";
+gpg_error_t
+gt_passwd (gpgme_tool_t gt, char *fpr)
+{
+  gpg_error_t err;
+  gpgme_key_t key;
+
+  err = gpgme_get_key (gt->ctx, fpr, &key, 0);
+  if (err)
+    return err;
+
+  err = gpgme_op_passwd (gt->ctx, key, 0);
+  gpgme_key_unref (key);
+  return err;
+}
+
+
+
+
+/* TODO */
 #define GT_RESULT_ENCRYPT 0x1
 #define GT_RESULT_DECRYPT 0x2
 #define GT_RESULT_SIGN 0x4
@@ -1974,6 +1995,16 @@ cmd_vfs_create (assuan_context_t ctx, char *line)
 }
 
 
+static gpg_error_t
+cmd_passwd (assuan_context_t ctx, char *line)
+{
+  struct server *server = assuan_get_pointer (ctx);
+
+  return gt_passwd (server->gt, line);
+}
+
+
+
 static gpg_error_t
 cmd_result (assuan_context_t ctx, char *line)
 {
@@ -2076,6 +2107,7 @@ register_commands (assuan_context_t ctx)
     { "STRERROR", cmd_strerror },
     { "PUBKEY_ALGO_NAME", cmd_pubkey_algo_name },
     { "HASH_ALGO_NAME", cmd_hash_algo_name },
+    { "PASSWD", cmd_passwd, hlp_passwd },
     { NULL }
   };
   int idx;

src/gpgme.c

@@ -792,6 +792,12 @@ gpgme_pubkey_algo_name (gpgme_pubkey_algo_t algo)
     case GPGME_PK_ELG:
       return "ELG";
 
+    case GPGME_PK_ECDSA:
+      return "ECDSA";
+
+    case GPGME_PK_ECDH:
+      return "ECDH";
+
     default:
       return NULL;
     }

src/gpgme.def

@@ -196,5 +196,8 @@ EXPORTS
     gpgme_set_sub_protocol                @150
     gpgme_get_sub_protocol                @151
 
+    gpgme_op_passwd_start                 @152
+    gpgme_op_passwd                       @153
+
 ; END
 

src/gpgme.h.in

@@ -1,6 +1,7 @@
 /* gpgme.h - Public interface to GnuPG Made Easy.                   -*- c -*-
    Copyright (C) 2000 Werner Koch (dd9jn)
-   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2009 g10 Code GmbH
+   Copyright (C) 2001, 2002, 2003, 2004, 2005, 2007, 2009
+                 2010 g10 Code GmbH
 
    This file is part of GPGME.
  
@@ -209,7 +210,9 @@ typedef enum
     GPGME_PK_RSA_S = 3,
     GPGME_PK_ELG_E = 16,
     GPGME_PK_DSA   = 17,
-    GPGME_PK_ELG   = 20
+    GPGME_PK_ELG   = 20,
+    GPGME_PK_ECDSA = 301,
+    GPGME_PK_ECDH  = 302
   }
 gpgme_pubkey_algo_t;
 
@@ -1664,6 +1667,14 @@ gpgme_error_t gpgme_op_keylist_next (gpgme_ctx_t ctx, gpgme_key_t *r_key);
 /* Terminate a pending keylist operation within CTX.  */
 gpgme_error_t gpgme_op_keylist_end (gpgme_ctx_t ctx);
 
+/* Change the passphrase for KEY.  FLAGS is reserved for future use
+   and must be passed as 0.  */
+gpgme_error_t gpgme_op_passwd_start (gpgme_ctx_t ctx, gpgme_key_t key,
+                                     unsigned int flags);
+gpgme_error_t gpgme_op_passwd (gpgme_ctx_t ctx, gpgme_key_t key,
+                               unsigned int flags);
+
+
 
 /* Trust items and operations.  */
 

src/libgpgme.vers

@@ -76,6 +76,9 @@ GPGME_1.1 {
     gpgme_key_from_uid;
     gpgme_set_sub_protocol;
     gpgme_get_sub_protocol;
+
+    gpgme_op_passwd_start;
+    gpgme_op_passwd;
 };
 
 

src/passwd.c

@@ -0,0 +1,95 @@
+/* passwd.c - Passphrase changing function
+   Copyright (C) 2010 g10 Code GmbH
+
+   This file is part of GPGME.
+ 
+   GPGME is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+   
+   GPGME is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+   
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "gpgme.h"
+#include "debug.h"
+#include "context.h"
+#include "ops.h"
+
+
+static gpgme_error_t
+passwd_status_handler (void *priv, gpgme_status_code_t code, char *args)
+{
+  (void)priv;
+  (void)code;
+  (void)args;
+  return 0;
+}
+
+
+static gpgme_error_t
+passwd_start (gpgme_ctx_t ctx, int synchronous, gpgme_key_t key,
+              unsigned int flags)
+{
+  gpgme_error_t err;
+
+  if (!key)
+    return gpg_error (GPG_ERR_INV_VALUE);
+  if (flags)
+    return gpg_error (GPG_ERR_INV_FLAG);
+
+  err = _gpgme_op_reset (ctx, synchronous);
+  if (err)
+    return err;
+
+  _gpgme_engine_set_status_handler (ctx->engine, passwd_status_handler, ctx);
+
+  return _gpgme_engine_op_passwd (ctx->engine, key, flags);
+}
+
+
+
+/* Change the passphrase for KEY.  FLAGS is reserved for future use
+   and must be passed as 0.  The engine is expected to present a user
+   interface to enter the old and the new passphrase.  This is the
+   asynchronous variant. 
+
+   Note that if ever the need arises to supply a passphrase we can do
+   this with a flag value and the passphrase callback feature.  */
+gpgme_error_t
+gpgme_op_passwd_start (gpgme_ctx_t ctx, gpgme_key_t key, unsigned int flags)
+{
+  gpg_error_t err;
+  TRACE_BEG2 (DEBUG_CTX, "gpgme_op_passwd_start", ctx,
+	      "key=%p, flags=0x%x", key, flags);
+  err = passwd_start (ctx, 0, key, flags);
+  return TRACE_ERR (err);
+}
+
+
+/* Change the passphrase for KEY.  FLAGS is reserved for future use
+   and must be passed as 0.  This is the synchronous variant.  */
+gpgme_error_t
+gpgme_op_passwd (gpgme_ctx_t ctx, gpgme_key_t key, unsigned int flags)
+{
+  gpgme_error_t err;
+
+  TRACE_BEG2 (DEBUG_CTX, "gpgme_op_passwd", ctx,
+	      "key=%p, flags=0x%x", key, flags);
+
+  err = passwd_start (ctx, 1, key, flags);
+  if (!err)
+    err = _gpgme_wait_one (ctx);
+  return TRACE_ERR (err);
+}
+