agent: New option --check-sym-passphrase-pattern.

* agent/gpg-agent.c (oCheckSymPassphrasePattern): New.
(opts): Add --check-sym-passphrase-pattern.
(parse_rereadable_options): Set option.
(main): Return option info.
* tools/gpgconf-comp.c: Add new option.
* agent/agent.h (opt): Add var check_sym_passphrase_pattern.
(struct pin_entry_info_s): Add var constraints_flags.
(CHECK_CONSTRAINTS_NOT_EMPTY): New to replace a hardwired 1.
(CHECK_CONSTRAINTS_NEW_SYMKEY): New.
* agent/genkey.c (check_passphrase_pattern): Rename to ...
(do_check_passphrase_pattern): this to make code reading
easier. Handle the --check-sym-passphrase-pattern option.
(check_passphrase_constraints): Replace arg no_empty by a generic
flags arg.  Also handle --check-sym-passphrase-pattern here.
* agent/command.c (cmd_get_passphrase): In --newsymkey mode pass
CHECK_CONSTRAINTS_NEW_SYMKEY flag.
* agent/call-pinentry.c (struct entry_parm_s): Add constraints_flags.
(struct inq_cb_parm_s): New.
(inq_cb): Use new struct for parameter passing.  Pass flags to teh
constraints checking.
(do_getpin): Pass constraints flag down.
(agent_askpin): Take constraints flag from the supplied pinentry
struct.
--

Requirements for a passphrase to protect a private key and for a
passphrase used for symmetric encryption are different.  Thus a
the use of a different pattern file will be useful.  Note that a
pattern file can be used to replace the other passphrase constraints
options and thus we don't need to duplicate them for symmetric
encryption.

GnuPG-bug-id: 5517
Signed-off-by: Werner Koch <wk@gnupg.org>
Backported-from-master: 7c45a69eb9
agent: New option --check-sym-passphrase-pattern.

agent/agent.h

@@ -117,8 +117,11 @@ struct
   /* The minimum number of non-alpha characters in a passphrase.  */
   unsigned int min_passphrase_nonalpha;
 
-  /* File name with a patternfile or NULL if not enabled.  */
+  /* File name with a patternfile or NULL if not enabled.  If the
+   * second one is set, it is used for symmetric only encryption
+   * instead of the former. */
   const char *check_passphrase_pattern;
+  const char *check_sym_passphrase_pattern;
 
   /* If not 0 the user is asked to change his passphrase after these
      number of days.  */
@@ -287,6 +290,7 @@ struct pin_entry_info_s
   int min_digits; /* min. number of digits required or 0 for freeform entry */
   int max_digits; /* max. number of allowed digits allowed*/
   int max_tries;  /* max. number of allowed tries.  */
+  unsigned int constraints_flags;  /* CHECK_CONSTRAINTS_... */
   int failed_tries; /* Number of tries so far failed.  */
   int with_qualitybar; /* Set if the quality bar should be displayed.  */
   int with_repeat;  /* Request repetition of the passphrase.  */
@@ -493,7 +497,11 @@ int agent_pkdecrypt (ctrl_t ctrl, const char *desc_text,
                      membuf_t *outbuf, int *r_padding);
 
 /*-- genkey.c --*/
-int check_passphrase_constraints (ctrl_t ctrl, const char *pw, int no_empty,
+#define CHECK_CONSTRAINTS_NOT_EMPTY  1
+#define CHECK_CONSTRAINTS_NEW_SYMKEY 2
+
+int check_passphrase_constraints (ctrl_t ctrl, const char *pw,
+                                  unsigned int flags,
 				  char **failed_constraint);
 gpg_error_t agent_ask_new_passphrase (ctrl_t ctrl, const char *prompt,
                                       char **r_passphrase);