gpg: Initial support for generating Kyber subkeys.

* common/openpgpdefs.h (PUBKEY_ALGO_KY768_25519): Remove.
(PUBKEY_ALGO_KY1024_448): Remove.
(PUBKEY_ALGO_KYBER): New.  Use them everywhere instead of the removed.

* g10/build-packet.c (gpg_mpi_write_nohdr): Rename to
(gpg_mpi_write_opaque_nohdr): this.  Change callers.
(gpg_mpi_write_opaque_32): New.
(do_key): Support Kyber keys using the revised format.
* g10/gpg.h (MAX_EXTERN_KEYPARM_BITS): New.
* g10/parse-packet.c (read_octet_string): Add arg nbytes so support
reading with a length prefix.  Adjust callers.
(parse_key): Parse Kyber public keys.
* g10/misc.c (pubkey_get_npkey): Support Kyber.
(pubkey_get_nskey): Ditto.

* g10/keyid.c (pubkey_string): Support dual algorithms.
(do_hash_public_key): Support Kyber.
(nbits_from_pk): Ditto.
(keygrip_from_pk): Return the Kyber part for the ECC+Kyber dual algo.

* g10/keygen.c (struct common_gen_cb_parm_s): Add genkey_result2.
Note that this callback is not yet used.
(ecckey_from_sexp): Add optional arg sexp2 and use it for Kyber.
Change callers.
(ecckey_from_sexp): Do not leak LIST in case of an error.
(common_gen): Add arg keyparms2, change callers, and support Kyber.
(gen_kyber): New.
(get_keysize_range): Support Kyber.
(fixup_keysize): Simplify and support Kyber.
(do_create): Handle Kyber.
(parse_key_parameter_part): Remove algo strings "ky768" and "ky1024"
and add a generic "kyber" with default parameters.
--

This uses a revised format which is more aligned with the usual
OpenPGP structure.  A lot of things are still missing.  For example
support for handling two keygrips and checking both of them in a -K
listing.  There is also only ky768_bp384 as fixed algorithm for now.
No passphrase for the Kyber part of the dual algorithm is on purpose.

A test was done using

  gpg --quick-gen-key pqc1 nistp256

and then running

  gpg -v --quick-add-key <fingerprint> kyber

which creates a v5 subkey on a v4 primary key.  A second test using

  gpg --quick-gen-key pqc2 Ed448

followed by a --quick-add-key created a v5 key with a v5 subkey.

GnuPG-bug-id: 6815

1 files changed, 4 insertions, 4 deletions

diff --git a/g10/misc.c b/g10/misc.c
index 24242cc30..432fe1760 100644
--- a/g10/misc.c
+++ b/g10/misc.c
@@ -801,8 +801,7 @@ openpgp_pk_algo_usage ( int algo )
           use = PUBKEY_USAGE_CERT | PUBKEY_USAGE_SIG | PUBKEY_USAGE_AUTH;
           break;
 
-      case PUBKEY_ALGO_KY768_25519:
-      case PUBKEY_ALGO_KY1024_448:
+      case PUBKEY_ALGO_KYBER:
           use = PUBKEY_USAGE_ENC | PUBKEY_USAGE_RENC;
           break;
 
@@ -1724,6 +1723,7 @@ pubkey_get_npkey (pubkey_algo_t algo)
     case PUBKEY_ALGO_ECDSA:     return 2;
     case PUBKEY_ALGO_ELGAMAL:   return 3;
     case PUBKEY_ALGO_EDDSA:     return 2;
+    case PUBKEY_ALGO_KYBER:     return 3;
     default: return 0;
     }
 }
@@ -1744,6 +1744,7 @@ pubkey_get_nskey (pubkey_algo_t algo)
     case PUBKEY_ALGO_ECDSA:     return 3;
     case PUBKEY_ALGO_ELGAMAL:   return 4;
     case PUBKEY_ALGO_EDDSA:     return 3;
+    case PUBKEY_ALGO_KYBER:     return 5;
     default: return 0;
     }
 }
@@ -1783,8 +1784,7 @@ pubkey_get_nenc (pubkey_algo_t algo)
     case PUBKEY_ALGO_ECDSA:     return 0;
     case PUBKEY_ALGO_ELGAMAL:   return 2;
     case PUBKEY_ALGO_EDDSA:     return 0;
-    case PUBKEY_ALGO_KY768_25519: return 4;
-    case PUBKEY_ALGO_KY1024_448:  return 4;
+    case PUBKEY_ALGO_KYBER:     return 4;
     default: return 0;
     }
 }