core: Implement adding ADSKs through gpgme_createsubkey

* src/engine-gpg.c: Add and use function for adding ADSKs.
* src/genkey.c: Prevent error due to no status line.
* src/gpgme.h.in: Add flag GPGME_CREATE_ADSK
* doc/gpgme.texi: Add documentation for ADSKs
* tests/run-genkey.c: Add test for adding ADSKs
--

This adds the ability to add ADSKs through
the gpgme_createsubkey interface.
The function must be called with NULL userid,
the ADSK fingerprint in algo
and the GPGME_CREATE_ADSK flag.

doc/gpgme.texi

@@ -4355,6 +4355,11 @@ override this check.
 
 Request generation of keys that do not expire.
 
+@item GPGME_CREATE_ADSK
+@since{1.24.0}
+
+Add an ADSK to the key.
+
 @end table
 
 After the operation completed successfully, information about the
@@ -4430,6 +4435,10 @@ values for timestamps and thus can only encode dates up to the year
 @var{flags} takes the same values as described above for
 @code{gpgme_op_createkey}.
 
+If the @code{GPGME_CREATE_ADSK} flag is set, the subkey fingerprint
+given in the @code{algo} parameter is added as an ADSK
+to the key.
+
 After the operation completed successfully, information about the
 created key can be retrieved with @code{gpgme_op_genkey_result}.
 

src/engine-gpg.c

@@ -2855,6 +2855,33 @@ gpg_adduid (engine_gpg_t gpg,
 }
 
 
+static gpgme_error_t
+gpg_addadsk (engine_gpg_t gpg, gpgme_key_t key, const char *adskfpr)
+{
+  gpgme_error_t err;
+
+  if (!key || !key->fpr)
+    return gpg_error (GPG_ERR_INV_ARG);
+
+  if (!adskfpr || !*adskfpr)
+    return gpg_error (GPG_ERR_INV_ARG);
+
+  if (!have_gpg_version (gpg, "2.4.1"))
+    return gpg_error (GPG_ERR_NOT_SUPPORTED);
+
+  err = add_arg (gpg, "--quick-add-adsk");
+  if (!err)
+    err = add_arg (gpg, "--");
+  if (!err)
+    err = add_arg (gpg, key->fpr);
+  if (!err)
+    err = add_arg (gpg, adskfpr);
+  if (!err)
+    err = start (gpg);
+  return err;
+}
+
+
 static gpgme_error_t
 gpg_genkey (void *engine,
             const char *userid, const char *algo,
@@ -2878,6 +2905,8 @@ gpg_genkey (void *engine,
    * !USERID &&  KEY          - Add a new subkey to KEY (gpg >= 2.1.14)
    *  USERID &&  KEY && !ALGO - Add a new user id to KEY (gpg >= 2.1.14).
    *                            or set a flag on a user id.
+   * !USERID &&  KEY &&  ALGO
+   *    &&  GPGME_CREATE_ADSK - Add ALGO as an ADSK to KEY.
    */
   if (help_data)
     {
@@ -2894,10 +2923,12 @@ gpg_genkey (void *engine,
     err = gpg_error (GPG_ERR_NOT_SUPPORTED);
   else if (userid && !key)
     err = gpg_createkey (gpg, userid, algo, expires, flags, extraflags);
-  else if (!userid && key)
+  else if (!userid && key && !(flags & GPGME_CREATE_ADSK))
     err = gpg_addkey (gpg, algo, expires, key, flags, extraflags);
   else if (userid && key && !algo)
     err = gpg_adduid (gpg, key, userid, extraflags);
+  else if (!userid && key && algo && (flags & GPGME_CREATE_ADSK))
+    err = gpg_addadsk (gpg, key, algo);
   else
     err = gpg_error (GPG_ERR_INV_VALUE);
 

src/genkey.c

@@ -48,6 +48,9 @@ typedef struct
 
   /* The key parameters passed to the crypto engine.  */
   gpgme_data_t key_parameter;
+
+  /* Flag to indicate that an ADSK is to be added.  */
+  unsigned int adskmode : 1;
 } *op_data_t;
 
 
@@ -180,7 +183,7 @@ genkey_status_handler (void *priv, gpgme_status_code_t code, char *args)
     case GPGME_STATUS_EOF:
       if (opd->error_code)
         return opd->error_code;
-      else if (!opd->uidmode && !opd->result.primary && !opd->result.sub)
+      else if (!opd->uidmode && !opd->adskmode && !opd->result.primary && !opd->result.sub)
 	return gpg_error (GPG_ERR_GENERAL);
       else if (opd->failure_code)
         return opd->failure_code;
@@ -445,6 +448,9 @@ createsubkey_start (gpgme_ctx_t ctx, int synchronous,
         return err;
     }
 
+  if (flags & GPGME_CREATE_ADSK)
+    opd->adskmode = 1;
+
   return _gpgme_engine_op_genkey (ctx->engine,
                                   NULL, algo, reserved, expires,
                                   key, flags,

src/gpgme.h.in

@@ -1838,6 +1838,7 @@ gpgme_error_t gpgme_op_export_keys (gpgme_ctx_t ctx,
 #define GPGME_CREATE_WANTSEC    (1 << 11) /* Return the secret key.    */
 #define GPGME_CREATE_FORCE      (1 << 12) /* Force creation.           */
 #define GPGME_CREATE_NOEXPIRE   (1 << 13) /* Create w/o expiration.    */
+#define GPGME_CREATE_ADSK       (1 << 14) /* Add an ADSK               */
 
 
 /* An object to return result from a key generation.

tests/run-genkey.c

@@ -215,6 +215,7 @@ show_usage (int ex)
          "   for revuid: FPR    USERID\n"
          "   for setexpire: FPR EXPIRE [SUBFPRS]\n"
          "   for set-primary: FPR    USERID\n"
+         "   for addadsk: FPR   ADSKFPR\n"
          "Options:\n"
          "  --addkey         add a subkey to the key with FPR\n"
          "  --adduid         add a user id to the key with FPR\n"
@@ -222,6 +223,7 @@ show_usage (int ex)
          "  --set-primary    set the primary key flag on USERID\n"
          "  --setexpire      set the expiration time of the key FPR\n"
          "                   or of its subkeys SUBFPRS\n"
+         "  --addadsk        add the subkey with ADSKFPR to the key FPR\n"
          "  --verbose        run in verbose mode\n"
          "  --status         print status lines from the backend\n"
          "  --progress       print progress info\n"
@@ -250,6 +252,7 @@ main (int argc, char **argv)
   int revuid = 0;
   int setpri = 0;
   int setexpire = 0;
+  int addadsk = 0;
   const char *userid;
   const char *algo = NULL;
   const char *newuserid = NULL;
@@ -260,6 +263,7 @@ main (int argc, char **argv)
   int i;
   size_t n;
   char *subfprs_buffer = NULL;
+  char *adskfpr = NULL;
 
   if (argc)
     { argc--; argv++; }
@@ -281,6 +285,7 @@ main (int argc, char **argv)
           revuid = 0;
           setpri = 0;
           setexpire = 0;
+          addadsk = 0;
           argc--; argv++;
         }
       else if (!strcmp (*argv, "--adduid"))
@@ -290,6 +295,7 @@ main (int argc, char **argv)
           revuid = 0;
           setpri = 0;
           setexpire = 0;
+          addadsk = 0;
           argc--; argv++;
         }
       else if (!strcmp (*argv, "--revuid"))
@@ -299,6 +305,7 @@ main (int argc, char **argv)
           revuid = 1;
           setpri = 0;
           setexpire = 0;
+          addadsk = 0;
           argc--; argv++;
         }
       else if (!strcmp (*argv, "--set-primary"))
@@ -308,6 +315,7 @@ main (int argc, char **argv)
           revuid = 0;
           setpri = 1;
           setexpire = 0;
+          addadsk = 0;
           argc--; argv++;
         }
       else if (!strcmp (*argv, "--setexpire"))
@@ -317,6 +325,17 @@ main (int argc, char **argv)
           revuid = 0;
           setpri = 0;
           setexpire = 1;
+          addadsk = 0;
+          argc--; argv++;
+        }
+      else if (!strcmp (*argv, "--addadsk"))
+        {
+          addkey = 0;
+          adduid = 0;
+          revuid = 0;
+          setpri = 0;
+          setexpire = 0;
+          addadsk = 1;
           argc--; argv++;
         }
       else if (!strcmp (*argv, "--verbose"))
@@ -412,6 +431,13 @@ main (int argc, char **argv)
           subfprs = NULL;
         }
     }
+  else if (addadsk)
+    {
+      if (argc != 2)
+        show_usage(1);
+      userid = argv[0];
+      adskfpr = argv[1];
+    }
   else
     {
       if (!argc || argc > 4)
@@ -445,7 +471,7 @@ main (int argc, char **argv)
     }
 
 
-  if (addkey || adduid || revuid || setpri || setexpire)
+  if (addkey || adduid || revuid || setpri || setexpire || addadsk)
     {
       gpgme_key_t akey;
 
@@ -507,6 +533,17 @@ main (int argc, char **argv)
               exit (1);
             }
         }
+      else if (addadsk)
+        {
+          err = gpgme_op_createsubkey(ctx, akey, adskfpr, 0, 0,
+                                      GPGME_CREATE_ADSK);
+          if (err)
+            {
+              fprintf (stderr, PGM ": gpgme_op_createsubkey failed: %s\n",
+                      gpg_strerror (err));
+              exit (1);
+            }
+        }
 
       gpgme_key_unref (akey);
     }
@@ -521,7 +558,7 @@ main (int argc, char **argv)
         }
     }
 
-  if (!setpri && !setexpire)
+  if (!setpri && !setexpire && !addadsk)
     {
       result = gpgme_op_genkey_result (ctx);
       if (!result)