common,gpg,scd,sm: Fix for Curve25519 OID supporting new and old.

* common/util.h (openpgp_curve_to_oid): Add new argument to select OID
by OpenPGP version.
* common/openpgp-oid.c (openpgp_curve_to_oid): Implement returning
selected OID for Curve25519.
* common/openpgp-fpr.c (compute_openpgp_fpr_ecc): Follow the change,
selecting by the version.
* g10/export.c (match_curve_skey_pk): Likewise.
(transfer_format_to_openpgp): Likewise.
* g10/gpg.c (list_config): Likewise, print new OID.
* g10/keygen.c (ecckey_from_sexp): Likewise, selecting by the version.
* sm/encrypt.c (ecdh_encrypt): Likewise, don't care.
* sm/minip12.c (build_ecc_key_sequence): Likewise, new OID.
* scd/app-openpgp.c (ecdh_params, gen_challenge): Likewise, don't
care.
(ecc_read_pubkey, change_keyattr_from_string, ecc_writekey): Likewise,
old OID.

--

GnuPG-bug-id: 7316
Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>

common/openpgp-fpr.c

@@ -231,7 +231,8 @@ compute_openpgp_fpr_ecc (int keyversion, unsigned long timestamp,
   unsigned char nbits_q[2];
   unsigned int n;
 
-  curveoidstr = openpgp_curve_to_oid (curvename, &curvebits, &pgpalgo);
+  curveoidstr = openpgp_curve_to_oid (curvename, &curvebits, &pgpalgo,
+                                      (keyversion > 4));
   err = openpgp_oid_from_str (curveoidstr, &curveoid);
   if (err)
     goto leave;

common/openpgp-oid.c

@@ -443,9 +443,11 @@ openpgp_oid_is_cv448 (gcry_mpi_t a)
    curve names.  If R_ALGO is not NULL and a specific ECC algorithm is
    required for this curve its OpenPGP algorithm number is stored
    there; otherwise 0 is stored which indicates that ECDSA or ECDH can
-   be used. */
+   be used.  SELECTOR specifies which OID should be returned: -1 for
+   don't care, 0 for old OID, 1 for new OID.  */
 const char *
-openpgp_curve_to_oid (const char *name, unsigned int *r_nbits, int *r_algo)
+openpgp_curve_to_oid (const char *name, unsigned int *r_nbits, int *r_algo,
+                      int selector)
 {
   int i;
   unsigned int nbits = 0;
@@ -479,6 +481,14 @@ openpgp_curve_to_oid (const char *name, unsigned int *r_nbits, int *r_algo)
         }
     }
 
+  /* Special handling for Curve25519, where we have two valid OIDs.  */
+  if (algo && i == 0)
+    {
+      /* Select new OID, if wanted.  */
+      if (selector > 0)
+        oidstr = oidtable[2].oidstr;
+    }
+
   if (r_nbits)
     *r_nbits = nbits;
   if (r_algo)

common/util.h

@@ -230,7 +230,8 @@ int openpgp_oid_is_cv448 (gcry_mpi_t a);
 int openpgp_oid_is_ed448 (gcry_mpi_t a);
 enum gcry_kem_algos openpgp_oid_to_kem_algo (const char *oidname);
 const char *openpgp_curve_to_oid (const char *name,
-                                  unsigned int *r_nbits, int *r_algo);
+                                  unsigned int *r_nbits, int *r_algo,
+                                  int selector);
 const char *openpgp_oid_to_curve (const char *oid, int mode);
 const char *openpgp_oid_or_name_to_curve (const char *oidname, int canon);
 const char *openpgp_enum_curves (int *idxp);

g10/export.c

@@ -585,7 +585,7 @@ match_curve_skey_pk (gcry_sexp_t s_key, PKT_public_key *pk)
     }
   if (!strcmp (curve_str, "Ed448"))
     is_eddsa = 1;
-  oidstr = openpgp_curve_to_oid (curve_str, NULL, NULL);
+  oidstr = openpgp_curve_to_oid (curve_str, NULL, NULL, (pk->version > 4));
   if (!oidstr)
     {
       log_error ("no OID known for curve '%s'\n", curve_str);
@@ -1280,7 +1280,7 @@ transfer_format_to_openpgp (gcry_sexp_t s_pgp, PKT_public_key *pk)
           goto leave;
         }
 
-      oidstr = openpgp_curve_to_oid (curve, NULL, NULL);
+      oidstr = openpgp_curve_to_oid (curve, NULL, NULL, (pk->version > 4));
       if (!oidstr)
         {
           log_error ("no OID known for curve '%s'\n", curve);

g10/gpg.c

@@ -1983,7 +1983,7 @@ list_config(char *items)
 	  es_printf ("cfg:curveoid:");
           for (iter=0, first=1; (s = openpgp_enum_curves (&iter)); first = 0)
             {
-              s = openpgp_curve_to_oid (s, NULL, NULL);
+              s = openpgp_curve_to_oid (s, NULL, NULL, 1);
               es_printf ("%s%s", first?"":";", s? s:"[?]");
             }
 	  es_printf ("\n");

g10/keygen.c

@@ -1503,7 +1503,7 @@ ecckey_from_sexp (gcry_mpi_t *array, gcry_sexp_t sexp,
       goto leave;
     }
   gcry_sexp_release (l2);
-  oidstr = openpgp_curve_to_oid (curve, &nbits, NULL);
+  oidstr = openpgp_curve_to_oid (curve, &nbits, NULL, pkversion > 4);
   if (!oidstr)
     {
       /* That can't happen because we used one of the curves
@@ -1511,9 +1511,6 @@ ecckey_from_sexp (gcry_mpi_t *array, gcry_sexp_t sexp,
       err = gpg_error (GPG_ERR_INV_OBJ);
       goto leave;
     }
-  /* For v5 keys we prefer the modern OID for cv25519.  */
-  if (pkversion > 4 && !strcmp (oidstr, "1.3.6.1.4.1.3029.1.5.1"))
-    oidstr = "1.3.101.110";
 
   err = openpgp_oid_from_str (oidstr, &array[0]);
   if (err)

scd/app-openpgp.c

@@ -1759,7 +1759,7 @@ ecdh_params (const char *curve)
 {
   unsigned int nbits;
 
-  openpgp_curve_to_oid (curve, &nbits, NULL);
+  openpgp_curve_to_oid (curve, &nbits, NULL, -1);
 
   /* See RFC-6637 for those constants.
          0x03: Number of bytes
@@ -1801,7 +1801,7 @@ ecc_read_pubkey (app_t app, ctrl_t ctrl, int meta_update,
     }
 
   curve = app->app_local->keyattr[keyno].ecc.curve;
-  oidstr = openpgp_curve_to_oid (curve, NULL, NULL);
+  oidstr = openpgp_curve_to_oid (curve, NULL, NULL, 0);
   err = openpgp_oid_from_str (oidstr, &oid);
   if (err)
     return err;
@@ -4194,7 +4194,7 @@ change_keyattr_from_string (app_t app, ctrl_t ctrl,
       else
         {
           nbits = 0;
-          oidstr = openpgp_curve_to_oid (keyalgo, NULL, &algo);
+          oidstr = openpgp_curve_to_oid (keyalgo, NULL, &algo, 0);
           if (!oidstr)
             {
               err = gpg_error (GPG_ERR_INV_DATA);
@@ -4244,7 +4244,7 @@ change_keyattr_from_string (app_t app, ctrl_t ctrl,
       else if (algo == PUBKEY_ALGO_ECDH || algo == PUBKEY_ALGO_ECDSA
                || algo == PUBKEY_ALGO_EDDSA)
         {
-          oidstr = openpgp_curve_to_oid (string+n, NULL, NULL);
+          oidstr = openpgp_curve_to_oid (string+n, NULL, NULL, 0);
           if (!oidstr)
             {
               err = gpg_error (GPG_ERR_INV_DATA);
@@ -4821,7 +4821,7 @@ ecc_writekey (app_t app, ctrl_t ctrl,
       ecdh_param_len = 4;
     }
 
-  oidstr = openpgp_curve_to_oid (curve, &n, NULL);
+  oidstr = openpgp_curve_to_oid (curve, &n, NULL, 0);
   ecc_d_fixed_len = (n+7)/8;
   err = openpgp_oid_from_str (oidstr, &oid);
   if (err)
@@ -5552,7 +5552,7 @@ gen_challenge (app_t app, const void **r_data, size_t *r_datalen)
     {
       unsigned int n;
 
-      openpgp_curve_to_oid (app->app_local->keyattr[2].ecc.curve, &n, NULL);
+      openpgp_curve_to_oid (app->app_local->keyattr[2].ecc.curve, &n, NULL, -1);
       /* No hash algo header, and appropriate length of random octets,
          determined by field size of the curve.  */
       datalen = (n+7)/8;

sm/encrypt.c

@@ -218,7 +218,7 @@ ecdh_encrypt (DEK dek, gcry_sexp_t s_pkey, gcry_sexp_t *r_encval)
    * canonical numerical OID.  We also use this to get the size of the
    * curve which we need to figure out a suitable hash algo.  We
    * should have a Libgcrypt function to do this; see bug report #4926.  */
-  curve = openpgp_curve_to_oid (curvebuf, &curvebits, NULL);
+  curve = openpgp_curve_to_oid (curvebuf, &curvebits, NULL, -1);
   if (!curve)
     {
       err = gpg_error (GPG_ERR_UNKNOWN_CURVE);

sm/minip12.c

@@ -2596,7 +2596,7 @@ build_ecc_key_sequence (gcry_mpi_t *kparms, int mode, size_t *r_length)
   /* We need to use our OpenPGP mapping to turn a curve name into its
    * canonical numerical OID.  We should have a Libgcrypt function to
    * do this; see bug report #4926.  */
-  curve = openpgp_curve_to_oid (p, &curvebits, NULL);
+  curve = openpgp_curve_to_oid (p, &curvebits, NULL, 1);
   xfree (p);
   if (!curve)
     {