gpg: Simplify the pubkey_enc_list object

* g10/packet.h (struct pubkey_enc_list): Replace most by a
PKT_pubkey_enc member.
* g10/free-packet.c (free_pubkey_enc): Factor most stuff out to ...
(release_pubkey_enc_parts): new.
(copy_pubkey_enc_parts): New.
* g10/mainproc.c (release_list): Adjust for above change.
(proc_pubkey_enc): Ditto.
(print_pkenc_list): Ditto.
(proc_encrypted): Ditto.

g10/free-packet.c

@@ -52,8 +52,10 @@ free_symkey_enc( PKT_symkey_enc *enc )
     xfree(enc);
 }
 
+/* This is the core of free_pubkey_enc but does only release the
+ * allocated members of ENC.  */
 void
-free_pubkey_enc( PKT_pubkey_enc *enc )
+release_pubkey_enc_parts (PKT_pubkey_enc *enc)
 {
   int n, i;
   n = pubkey_get_nenc( enc->pubkey_algo );
@@ -61,9 +63,39 @@ free_pubkey_enc( PKT_pubkey_enc *enc )
     mpi_release (enc->data[0]);
   for (i=0; i < n; i++ )
     mpi_release (enc->data[i]);
+}
+
+void
+free_pubkey_enc (PKT_pubkey_enc *enc)
+{
+  release_pubkey_enc_parts (enc);
   xfree (enc);
 }
 
+
+/* Copy everything from SRC to DST.  This assumes that DST has been
+ * malloced or statically allocated. */
+void
+copy_pubkey_enc_parts (PKT_pubkey_enc *dst, PKT_pubkey_enc *src)
+{
+  int n, i;
+
+  dst->keyid[0] = src->keyid[0];
+  dst->keyid[1] = src->keyid[1];
+  dst->version  = src->version;
+  dst->pubkey_algo = src->pubkey_algo;
+  dst->seskey_algo = src->seskey_algo;
+  dst->throw_keyid = src->throw_keyid;
+
+  if (!(n = pubkey_get_nenc (dst->pubkey_algo)))
+    n = 1;  /* All data is in the first item as an opaque MPI. */
+  for (i=0; i < n; i++)
+    dst->data[i] = my_mpi_copy (src->data[i]);
+  for (; i < PUBKEY_MAX_NENC; i++)
+    dst->data[i] = NULL;
+}
+
+
 void
 free_seckey_enc( PKT_signature *sig )
 {

g10/mainproc.c

@@ -1,7 +1,7 @@
 /* mainproc.c - handle packets
  * Copyright (C) 1998-2009 Free Software Foundation, Inc.
  * Copyright (C) 2013-2014 Werner Koch
- * Copyright (C) 2020 g10 Code GmbH
+ * Copyright (C) 2020, 2024 g10 Code GmbH
  *
  * This file is part of GnuPG.
  *
@@ -141,10 +141,7 @@ release_list( CTX c )
     {
       struct pubkey_enc_list *tmp = c->pkenc_list->next;
 
-      mpi_release (c->pkenc_list->data[0]);
+      release_pubkey_enc_parts (&c->pkenc_list->d);
-      mpi_release (c->pkenc_list->data[1]);
-      mpi_release (c->pkenc_list->data[2]);
-      mpi_release (c->pkenc_list->data[3]);
       xfree (c->pkenc_list);
       c->pkenc_list = tmp;
     }
@@ -523,21 +520,10 @@ proc_pubkey_enc (CTX c, PACKET *pkt)
 
   if (!opt.list_only && !opt.override_session_key)
     {
-      struct pubkey_enc_list *x = xmalloc (sizeof *x);
+      struct pubkey_enc_list *x = xcalloc (1, sizeof *x);
 
-      x->keyid[0] = enc->keyid[0];
+      copy_pubkey_enc_parts (&x->d, enc);
-      x->keyid[1] = enc->keyid[1];
-      x->pubkey_algo = enc->pubkey_algo;
       x->result = -1;
-      x->seskey_algo = enc->seskey_algo;
-      x->data[0] = x->data[1] = x->data[2] = x->data[3] = NULL;
-      if (enc->data[0])
-        {
-          x->data[0] = mpi_copy (enc->data[0]);
-          x->data[1] = mpi_copy (enc->data[1]);
-          x->data[2] = mpi_copy (enc->data[2]);
-          x->data[3] = mpi_copy (enc->data[3]);
-        }
       x->next = c->pkenc_list;
       c->pkenc_list = x;
     }
@@ -561,22 +547,22 @@ print_pkenc_list (ctrl_t ctrl, struct pubkey_enc_list *list)
 
       pk = xmalloc_clear (sizeof *pk);
 
-      pk->pubkey_algo = list->pubkey_algo;
+      pk->pubkey_algo = list->d.pubkey_algo;
-      if (!get_pubkey (ctrl, pk, list->keyid))
+      if (!get_pubkey (ctrl, pk, list->d.keyid))
         {
           pubkey_string (pk, pkstrbuf, sizeof pkstrbuf);
 
           log_info (_("encrypted with %s key, ID %s, created %s\n"),
                     pkstrbuf, keystr_from_pk (pk),
                     strtimestamp (pk->timestamp));
-          p = get_user_id_native (ctrl, list->keyid);
+          p = get_user_id_native (ctrl, list->d.keyid);
           log_printf (_("      \"%s\"\n"), p);
           xfree (p);
         }
       else
         log_info (_("encrypted with %s key, ID %s\n"),
-                  openpgp_pk_algo_name (list->pubkey_algo),
+                  openpgp_pk_algo_name (list->d.pubkey_algo),
-                  keystr(list->keyid));
+                  keystr (list->d.keyid));
 
       if (opt.flags.require_pqc_encryption
           && pk->pubkey_algo != PUBKEY_ALGO_KYBER)
@@ -644,7 +630,7 @@ proc_encrypted (CTX c, PACKET *pkt)
               { /* Key was not tried or it caused an error.  */
                 char buf[20];
                 snprintf (buf, sizeof buf, "%08lX%08lX",
-                          (ulong)list->keyid[0], (ulong)list->keyid[1]);
+                          (ulong)list->d.keyid[0], (ulong)list->d.keyid[1]);
                 write_status_text (STATUS_NO_SECKEY, buf);
               }
         }
@@ -768,8 +754,8 @@ proc_encrypted (CTX c, PACKET *pkt)
       for (i = c->pkenc_list; i && compliant; i = i->next)
         {
           memset (pk, 0, sizeof *pk);
-          pk->pubkey_algo = i->pubkey_algo;
+          pk->pubkey_algo = i->d.pubkey_algo;
-          if (!get_pubkey (c->ctrl, pk, i->keyid)
+          if (!get_pubkey (c->ctrl, pk, i->d.keyid)
               && !gnupg_pk_is_compliant (CO_DE_VS, pk->pubkey_algo, 0,
                                          pk->pkey, nbits_from_pk (pk), NULL))
             compliant = 0;

g10/packet.h

@@ -159,11 +159,8 @@ typedef struct {
 struct pubkey_enc_list
 {
   struct pubkey_enc_list *next;
-  u32 keyid[2];
-  int pubkey_algo;
-  int seskey_algo;
   int result;
-  gcry_mpi_t data[PUBKEY_MAX_NENC];
+  PKT_pubkey_enc d;
 };
 
 
@@ -895,19 +892,28 @@ void free_notation (struct notation *notation);
 
 /*-- free-packet.c --*/
 void free_symkey_enc( PKT_symkey_enc *enc );
+
+void release_pubkey_enc_parts (PKT_pubkey_enc *enc);
 void free_pubkey_enc( PKT_pubkey_enc *enc );
+void copy_pubkey_enc_parts (PKT_pubkey_enc *dst, PKT_pubkey_enc *src);
+
 void free_seckey_enc( PKT_signature *enc );
+
 void release_public_key_parts( PKT_public_key *pk );
 void free_public_key( PKT_public_key *key );
+
 void free_attributes(PKT_user_id *uid);
 void free_user_id( PKT_user_id *uid );
 void free_comment( PKT_comment *rem );
 void free_packet (PACKET *pkt, parse_packet_ctx_t parsectx);
 prefitem_t *copy_prefs (const prefitem_t *prefs);
+
 PKT_public_key *copy_public_key_basics (PKT_public_key *d, PKT_public_key *s);
 PKT_public_key *copy_public_key( PKT_public_key *d, PKT_public_key *s );
+
 PKT_signature *copy_signature( PKT_signature *d, PKT_signature *s );
 PKT_user_id *scopy_user_id (PKT_user_id *sd );
+
 int cmp_public_keys( PKT_public_key *a, PKT_public_key *b );
 int cmp_signatures( PKT_signature *a, PKT_signature *b );
 int cmp_user_ids( PKT_user_id *a, PKT_user_id *b );

g10/pubkey-enc.c

@@ -115,23 +115,23 @@ get_session_key (ctrl_t ctrl, struct pubkey_enc_list *list, DEK *dek)
        */
       for (k = list; k; k = k->next)
         {
-          if (!(k->pubkey_algo == PUBKEY_ALGO_ELGAMAL_E
+          if (!(k->d.pubkey_algo == PUBKEY_ALGO_ELGAMAL_E
-                || k->pubkey_algo == PUBKEY_ALGO_ECDH
+                || k->d.pubkey_algo == PUBKEY_ALGO_ECDH
-                || k->pubkey_algo == PUBKEY_ALGO_KYBER
+                || k->d.pubkey_algo == PUBKEY_ALGO_KYBER
-                || k->pubkey_algo == PUBKEY_ALGO_RSA
+                || k->d.pubkey_algo == PUBKEY_ALGO_RSA
-                || k->pubkey_algo == PUBKEY_ALGO_RSA_E
+                || k->d.pubkey_algo == PUBKEY_ALGO_RSA_E
-                || k->pubkey_algo == PUBKEY_ALGO_ELGAMAL))
+                || k->d.pubkey_algo == PUBKEY_ALGO_ELGAMAL))
             continue;
 
-          if (openpgp_pk_test_algo2 (k->pubkey_algo, PUBKEY_USAGE_ENC))
+          if (openpgp_pk_test_algo2 (k->d.pubkey_algo, PUBKEY_USAGE_ENC))
             continue;
 
-          if (sk->pubkey_algo != k->pubkey_algo)
+          if (sk->pubkey_algo != k->d.pubkey_algo)
             continue;
 
           keyid_from_pk (sk, keyid);
 
-          if (!k->keyid[0] && !k->keyid[1])
+          if (!k->d.keyid[0] && !k->d.keyid[1])
             {
               if (opt.skip_hidden_recipients)
                 continue;
@@ -141,7 +141,7 @@ get_session_key (ctrl_t ctrl, struct pubkey_enc_list *list, DEK *dek)
                           keystr (keyid));
             }
           else if (opt.try_all_secrets
-                   || (k->keyid[0] == keyid[0] && k->keyid[1] == keyid[1]))
+                   || (k->d.keyid[0] == keyid[0] && k->d.keyid[1] == keyid[1]))
             {
               if (!opt.quiet && !(sk->pubkey_usage & PUBKEY_USAGE_XENC_MASK))
                 log_info (_("used key is not marked for encryption use.\n"));
@@ -153,7 +153,7 @@ get_session_key (ctrl_t ctrl, struct pubkey_enc_list *list, DEK *dek)
           k->result = err;
           if (!err)
             {
-              if (!opt.quiet && !k->keyid[0] && !k->keyid[1])
+              if (!opt.quiet && !k->d.keyid[0] && !k->d.keyid[1])
                 {
                   log_info (_("okay, we are the anonymous recipient.\n"));
                   if (!(sk->pubkey_usage & PUBKEY_USAGE_XENC_MASK))
@@ -215,28 +215,28 @@ get_it (ctrl_t ctrl,
   if (sk->pubkey_algo == PUBKEY_ALGO_ELGAMAL
       || sk->pubkey_algo == PUBKEY_ALGO_ELGAMAL_E)
     {
-      if (!enc->data[0] || !enc->data[1])
+      if (!enc->d.data[0] || !enc->d.data[1])
         err = gpg_error (GPG_ERR_BAD_MPI);
       else
         err = gcry_sexp_build (&s_data, NULL, "(enc-val(elg(a%m)(b%m)))",
-                               enc->data[0], enc->data[1]);
+                               enc->d.data[0], enc->d.data[1]);
     }
   else if (sk->pubkey_algo == PUBKEY_ALGO_RSA
            || sk->pubkey_algo == PUBKEY_ALGO_RSA_E)
     {
-      if (!enc->data[0])
+      if (!enc->d.data[0])
         err = gpg_error (GPG_ERR_BAD_MPI);
       else
         err = gcry_sexp_build (&s_data, NULL, "(enc-val(rsa(a%m)))",
-                               enc->data[0]);
+                               enc->d.data[0]);
     }
   else if (sk->pubkey_algo == PUBKEY_ALGO_ECDH)
     {
-      if (!enc->data[0] || !enc->data[1])
+      if (!enc->d.data[0] || !enc->d.data[1])
         err = gpg_error (GPG_ERR_BAD_MPI);
       else
         err = gcry_sexp_build (&s_data, NULL, "(enc-val(ecdh(s%m)(e%m)))",
-                               enc->data[1], enc->data[0]);
+                               enc->d.data[1], enc->d.data[0]);
     }
   else if (sk->pubkey_algo == PUBKEY_ALGO_KYBER)
     {
@@ -251,18 +251,18 @@ get_it (ctrl_t ctrl,
         }
       else
         {
-          fixedinfo[0] = enc->seskey_algo;
+          fixedinfo[0] = enc->d.seskey_algo;
           v5_fingerprint_from_pk (sk, fixedinfo+1, NULL);
           fixedlen = 33;
         }
 
-      if (!enc->data[0] || !enc->data[1] || !enc->data[2])
+      if (!enc->d.data[0] || !enc->d.data[1] || !enc->d.data[2])
         err = gpg_error (GPG_ERR_BAD_MPI);
       else
         err = gcry_sexp_build (&s_data, NULL,
                            "(enc-val(pqc(e%m)(k%m)(s%m)(c%d)(fixed-info%b)))",
-                           enc->data[0], enc->data[1], enc->data[2],
+                           enc->d.data[0], enc->d.data[1], enc->d.data[2],
-                           enc->seskey_algo, fixedlen, fixedinfo);
+                           enc->d.seskey_algo, fixedlen, fixedinfo);
     }
   else
     err = gpg_error (GPG_ERR_BUG);
@@ -316,15 +316,17 @@ get_it (ctrl_t ctrl,
           goto leave;
         }
       dek->keylen = nframe;
-      dek->algo = enc->seskey_algo;
+      dek->algo = enc->d.seskey_algo;
     }
   else if (sk->pubkey_algo == PUBKEY_ALGO_ECDH)
     {
       gcry_mpi_t decoded;
 
       /* At the beginning the frame are the bytes of shared point MPI.  */
-      err = pk_ecdh_decrypt (&decoded, fp, enc->data[1]/*encr data as an MPI*/,
+      err = pk_ecdh_decrypt (&decoded, fp,
-                             frame, nframe, sk->pkey);
+                             enc->d.data[1], /*encr data as an MPI*/
+                             frame, nframe,
+                             sk->pkey);
       if(err)
         goto leave;