allow for default algorithms in a gpg parameter file

NEWS

@@ -8,6 +8,9 @@ Noteworthy changes in version 2.1.x (under development)
 
  * The G13 tool for disk encryption key management has been added.
 
+ * The default for --include-cert is now to include all certificates
+   in the chain except for the root certificate.
+
  * Numerical values may now be used as an alternative to the
    debug-level keywords.
 

doc/DETAILS

@@ -823,11 +823,14 @@ The format of this file is as follows:
      used. Some syntactically checks may be performed.
      The currently defined parameters are:
      Key-Type: <algo-number>|<algo-string>
-	Starts a new parameter block by giving the type of the
+	Starts a new parameter block by giving the type of the primary
-	primary key. The algorithm must be capable of signing.
+	key. The algorithm must be capable of signing.  This is a
-	This is a required parameter.
+	required parameter.  It may be "default" to use the default
+	one; in this case don't give a Key-Usage and use "default" for
+	the Subkey-Type.
      Key-Length: <length-in-bits>
-	Length of the key in bits.  Default is 1024.
+	Length of the key in bits.  The default is returned by running
+        the command "gpg --gpgconf-list".
      Key-Usage: <usage-list>
         Space or comma delimited list of key usage, allowed values are
         "encrypt", "sign", and "auth".  This is used to generate the
@@ -835,13 +838,15 @@ The format of this file is as follows:
         this usage.  Note that OpenPGP requires that all primary keys
         are capable of certification, so no matter what usage is given
         here, the "cert" flag will be on.  If no Key-Usage is
-        specified, all the allowed usages for that particular
+        specified and the key-type is not "default", all allowed
-        algorithm are used.
+        usages for that particular algorithm are used; if it is not
+        given but "default" is used the usage will be "sign".
      Subkey-Type: <algo-number>|<algo-string>
 	This generates a secondary key.  Currently only one subkey
 	can be handled.
      Subkey-Length: <length-in-bits>
-	Length of the subkey in bits.  Default is 1024.
+	Length of the subkey in bits.  The default is returned by running
+        the command "gpg --gpgconf-list".
      Subkey-Usage: <usage-list>
         Similar to Key-Usage.
      Passphrase: <string>
@@ -892,9 +897,9 @@ The format of this file is as follows:
         keyserver URL for the key.
 
 
-Here is an example:
+Here is an example on how to create a key:
 $ cat >foo <<EOF
-     %echo Generating a standard key
+     %echo Generating a basic OpenPGP key
      Key-Type: DSA
      Key-Length: 1024
      Subkey-Type: ELG-E
@@ -919,6 +924,24 @@ $ gpg --no-default-keyring --secret-keyring ./foo.sec \
 sec  1024D/915A878D 2000-03-09 Joe Tester (with stupid passphrase) <joe@foo.bar>
 ssb  1024g/8F70E2C0 2000-03-09
 
+If you want to create a key with the default algorithms you would
+use these parameters:
+
+     %echo Generating a default key
+     Key-Type: default
+     Subkey-Type: default
+     Name-Real: Joe Tester
+     Name-Comment: with stupid passphrase
+     Name-Email: joe@foo.bar
+     Expire-Date: 0
+     Passphrase: abc
+     %pubring foo.pub
+     %secring foo.sec
+     # Do a commit here, so that we can later print "done" :-)
+     %commit
+     %echo done
+
+
 
 
 Layout of the TrustDB

g10/ChangeLog

@@ -1,3 +1,11 @@
+2009-12-04  Werner Koch  <wk@g10code.com>
+
+	* keygen.c (DEFAULT_STD_ALGO, DEFAULT_STD_KEYSIZE): New.
+	(ask_keysize): Use new macro.
+	(gen_rsa): Set default size if NBITS is 0.
+	(get_parameter_algo): Add algo name "default".  Add arg	R_DEFAULT.
+	(proc_parameter_file): Process default flag.
+
 2009-12-03  Werner Koch  <wk@g10code.com>
 
 	* gpg.c (set_debug): Allow for numerical debug leveles.  Print

g10/gpg.c

@@ -1617,8 +1617,8 @@ gpgconf_list (const char *configfile)
   printf ("debug-level:%lu:\"none:\n", GC_OPT_FLAG_DEFAULT);
   printf ("group:%lu:\n", GC_OPT_FLAG_NONE);
 
-  /* The next one is an info only item and should match what
+  /* The next one is an info only item and should match the macros at
-     keygen:ask_keysize actually implements.  */
+     the top of keygen.c  */
   printf ("default_pubkey_algo:%lu:\"%s:\n", GC_OPT_FLAG_DEFAULT,
           "RSA-2048");
 

g10/keygen.c

@@ -43,6 +43,12 @@
 #include "keyserver-internal.h"
 #include "call-agent.h"
 
+/* The default algorithms.  If you change them remember to change them
+   also in gpg.c:gpgconf_list.  You should also check that the value
+   is inside the bounds enforced by ask_keysize and gen_xxx.  */
+#define DEFAULT_STD_ALGO    GCRY_PK_RSA
+#define DEFAULT_STD_KEYSIZE 2048
+
 
 #define MAX_PREFS 30 
 
@@ -1426,6 +1432,9 @@ gen_rsa (int algo, unsigned nbits, KBNODE pub_root, KBNODE sec_root, DEK *dek,
 
   assert (is_RSA(algo));
 
+  if (!nbits)
+    nbits = DEFAULT_STD_KEYSIZE;
+
   if (nbits < 1024) 
     {
       nbits = 1024;
@@ -1765,9 +1774,7 @@ ask_algo (int addmode, int *r_subkey_algo, unsigned int *r_usage)
 static unsigned
 ask_keysize (int algo, unsigned int primary_keysize)
 {
-  /* NOTE: If you change the default key size/algo, remember to change
+  unsigned int nbits, min, def = DEFAULT_STD_KEYSIZE, max=4096;
-     it also in gpgconf.c:gpgconf_list.  */
-  unsigned int nbits, min, def=2048, max=4096;
   int for_subkey = !!primary_keysize;
   int autocomp = 0;
 
@@ -2382,22 +2389,37 @@ get_parameter_value( struct para_data_s *para, enum para_name key )
 }
 
 static int
-get_parameter_algo( struct para_data_s *para, enum para_name key )
+get_parameter_algo( struct para_data_s *para, enum para_name key, 
+                    int *r_default)
 {
-    int i;
+  int i;
-    struct para_data_s *r = get_parameter( para, key );
+  struct para_data_s *r = get_parameter( para, key );
-    if( !r )
+
-	return -1;
+  if (r_default)
-    if( digitp( r->u.value ) )
+    *r_default = 0;
-	i = atoi( r->u.value );
+
-    else if ( !strcmp ( r->u.value, "ELG-E")
+  if (!r)
-              || !strcmp ( r->u.value, "ELG") )
+    return -1;
-        i = GCRY_PK_ELG_E;
+
-    else
+  if (!ascii_strcasecmp (r->u.value, "default"))
-        i = gcry_pk_map_name (r->u.value);
+    {
-    if (i == PUBKEY_ALGO_RSA_E || i == PUBKEY_ALGO_RSA_S)
+      /* Note: If you change this default algo, remember to change it
-      i = 0; /* we don't want to allow generation of these algorithms */
+         also in gpg.c:gpgconf_list.  */
-    return i;
+      i = DEFAULT_STD_ALGO;
+      if (r_default)
+        *r_default = 1;
+    }
+  else if (digitp (r->u.value))
+    i = atoi( r->u.value );
+  else if (!strcmp (r->u.value, "ELG-E")
+           || !strcmp (r->u.value, "ELG"))
+    i = GCRY_PK_ELG_E;
+  else
+    i = gcry_pk_map_name (r->u.value);
+
+  if (i == PUBKEY_ALGO_RSA_E || i == PUBKEY_ALGO_RSA_S)
+    i = 0; /* we don't want to allow generation of these algorithms */
+  return i;
 }
 
 /* 
@@ -2541,13 +2563,15 @@ proc_parameter_file( struct para_data_s *para, const char *fname,
   const char *s1, *s2, *s3;
   size_t n;
   char *p;
-  int have_user_id=0,err,algo;
+  int is_default = 0;
+  int have_user_id = 0;
+  int err, algo;
 
   /* Check that we have all required parameters. */
   r = get_parameter( para, pKEYTYPE );
   if(r)
     {
-      algo=get_parameter_algo(para,pKEYTYPE);
+      algo = get_parameter_algo (para, pKEYTYPE, &is_default);
       if (openpgp_pk_test_algo2 (algo, PUBKEY_USAGE_SIG))
 	{
 	  log_error ("%s:%d: invalid algorithm\n", fname, r->lnr );
@@ -2563,10 +2587,13 @@ proc_parameter_file( struct para_data_s *para, const char *fname,
   err = parse_parameter_usage (fname, para, pKEYUSAGE);
   if (!err)
     {
-      /* Default to algo capabilities if key-usage is not provided */
+      /* Default to algo capabilities if key-usage is not provided and
+         no default algorithm has been requested.  */
       r = xmalloc_clear(sizeof(*r));
       r->key = pKEYUSAGE;
-      r->u.usage = openpgp_pk_algo_usage(algo);
+      r->u.usage = (is_default
+                    ? (PUBKEY_USAGE_CERT | PUBKEY_USAGE_SIG)
+                    : openpgp_pk_algo_usage(algo));
       r->next = para;
       para = r;
     }
@@ -2583,10 +2610,11 @@ proc_parameter_file( struct para_data_s *para, const char *fname,
         }
     }
 
+  is_default = 0;
   r = get_parameter( para, pSUBKEYTYPE );
   if(r)
     {
-      algo = get_parameter_algo (para, pSUBKEYTYPE);
+      algo = get_parameter_algo (para, pSUBKEYTYPE, &is_default);
       if (openpgp_pk_test_algo (algo))
 	{
 	  log_error ("%s:%d: invalid algorithm\n", fname, r->lnr );
@@ -2600,7 +2628,9 @@ proc_parameter_file( struct para_data_s *para, const char *fname,
 	     provided */
 	  r = xmalloc_clear (sizeof(*r));
 	  r->key = pSUBKEYUSAGE;
-	  r->u.usage = openpgp_pk_algo_usage (algo);
+	  r->u.usage = (is_default
+                        ? PUBKEY_USAGE_ENC
+                        : openpgp_pk_algo_usage (algo));
 	  r->next = para;
 	  para = r;
 	}
@@ -3441,7 +3471,7 @@ do_generate_keypair (struct para_data_s *para,
 
   if (!card)
     {
-      rc = do_create (get_parameter_algo( para, pKEYTYPE ),
+      rc = do_create (get_parameter_algo( para, pKEYTYPE, NULL ),
                       get_parameter_uint( para, pKEYLENGTH ),
                       pub_root, sec_root,
                       get_parameter_dek( para, pPASSPHRASE_DEK ),
@@ -3503,7 +3533,7 @@ do_generate_keypair (struct para_data_s *para,
     {
       if (!card)
         {
-          rc = do_create( get_parameter_algo( para, pSUBKEYTYPE ),
+          rc = do_create( get_parameter_algo( para, pSUBKEYTYPE, NULL ),
                           get_parameter_uint( para, pSUBKEYLENGTH ),
                           pub_root, sec_root,
                           get_parameter_dek( para, pPASSPHRASE_DEK ),
@@ -3612,7 +3642,8 @@ do_generate_keypair (struct para_data_s *para,
           int no_enc_rsa;
           PKT_public_key *pk;
 
-          no_enc_rsa = (get_parameter_algo (para, pKEYTYPE) == PUBKEY_ALGO_RSA
+          no_enc_rsa = ((get_parameter_algo (para, pKEYTYPE, NULL)
+                         == PUBKEY_ALGO_RSA)
                         && get_parameter_uint (para, pKEYUSAGE)
                         && !((get_parameter_uint (para, pKEYUSAGE)
                               & PUBKEY_USAGE_ENC)) );
@@ -3634,7 +3665,7 @@ do_generate_keypair (struct para_data_s *para,
             
           
           if (!opt.batch
-              && (get_parameter_algo (para, pKEYTYPE) == PUBKEY_ALGO_DSA
+              && (get_parameter_algo (para, pKEYTYPE, NULL) == PUBKEY_ALGO_DSA
                   || no_enc_rsa )
               && !get_parameter (para, pSUBKEYTYPE) )
             {