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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
This commit is contained in:
Werner Koch 2024-04-03 18:00:44 +02:00
parent 6c1dd3afd1
commit 97f5159495
No known key found for this signature in database
GPG key ID: E3FDFF218E45B72B
9 changed files with 461 additions and 110 deletions

View file

@ -139,6 +139,9 @@ struct common_gen_cb_parm_s
* may take a copy of this so that the result can be used after we
* are back from the deep key generation call stack. */
gcry_sexp_t genkey_result;
/* For a dual algorithms the result of the second algorithm
* (e.g. Kyber). */
gcry_sexp_t genkey_result2;
};
typedef struct common_gen_cb_parm_s *common_gen_cb_parm_t;
@ -1311,8 +1314,12 @@ curve_is_448 (gcry_sexp_t sexp)
}
/* Extract the parameters in OpenPGP format from SEXP and put them
* into the caller provided ARRAY. SEXP2 is used to provide the
* parameters for dual algorithm (e.g. Kyber). */
static gpg_error_t
ecckey_from_sexp (gcry_mpi_t *array, gcry_sexp_t sexp, int algo)
ecckey_from_sexp (gcry_mpi_t *array, gcry_sexp_t sexp,
gcry_sexp_t sexp2, int algo)
{
gpg_error_t err;
gcry_sexp_t list, l2;
@ -1364,8 +1371,46 @@ ecckey_from_sexp (gcry_mpi_t *array, gcry_sexp_t sexp, int algo)
goto leave;
gcry_sexp_release (list);
list = NULL;
if (algo == PUBKEY_ALGO_ECDH)
if (algo == PUBKEY_ALGO_KYBER)
{
if (!sexp2)
{
err = gpg_error (GPG_ERR_MISSING_VALUE);
goto leave;
}
list = gcry_sexp_find_token (sexp2, "public-key", 0);
if (!list)
{
err = gpg_error (GPG_ERR_INV_OBJ);
goto leave;
}
l2 = gcry_sexp_cadr (list);
gcry_sexp_release (list);
list = l2;
if (!list)
{
err = gpg_error (GPG_ERR_NO_OBJ);
goto leave;
}
l2 = gcry_sexp_find_token (list, "p", 1);
if (!l2)
{
err = gpg_error (GPG_ERR_NO_OBJ); /* required parameter not found */
goto leave;
}
array[2] = gcry_sexp_nth_mpi (l2, 1, GCRYMPI_FMT_OPAQUE);
gcry_sexp_release (l2);
if (!array[2])
{
err = gpg_error (GPG_ERR_INV_OBJ); /* required parameter invalid */
goto leave;
}
}
else if (algo == PUBKEY_ALGO_ECDH)
{
array[2] = pk_ecdh_default_params (nbits);
if (!array[2])
@ -1377,6 +1422,7 @@ ecckey_from_sexp (gcry_mpi_t *array, gcry_sexp_t sexp, int algo)
leave:
xfree (curve);
gcry_sexp_release (list);
if (err)
{
for (i=0; i < 3; i++)
@ -1515,7 +1561,7 @@ do_create_from_keygrip (ctrl_t ctrl, int algo,
if (algo == PUBKEY_ALGO_ECDSA
|| algo == PUBKEY_ALGO_EDDSA
|| algo == PUBKEY_ALGO_ECDH )
err = ecckey_from_sexp (pk->pkey, s_key, algo);
err = ecckey_from_sexp (pk->pkey, s_key, NULL, algo);
else
err = key_from_sexp (pk->pkey, s_key, "public-key", algoelem);
if (err)
@ -1543,12 +1589,13 @@ do_create_from_keygrip (ctrl_t ctrl, int algo,
}
/* Common code for the key generation function gen_xxx. The optinal
/* Common code for the key generation function gen_xxx. The optional
* (COMMON_GEN_CB,COMMON_GEN_CB_PARM) can be used as communication
* object.
* object. A KEYPARMS2 forces the use of a dual key (e.g. Kyber+ECC).
*/
static int
common_gen (const char *keyparms, int algo, const char *algoelem,
common_gen (const char *keyparms, const char *keyparms2,
int algo, const char *algoelem,
kbnode_t pub_root, u32 timestamp, u32 expireval, int is_subkey,
int keygen_flags, const char *passphrase,
char **cache_nonce_addr, char **passwd_nonce_addr,
@ -1559,6 +1606,7 @@ common_gen (const char *keyparms, int algo, const char *algoelem,
PACKET *pkt;
PKT_public_key *pk;
gcry_sexp_t s_key;
gcry_sexp_t s_key2 = NULL;
err = agent_genkey (NULL, cache_nonce_addr, passwd_nonce_addr, keyparms,
!!(keygen_flags & KEYGEN_FLAG_NO_PROTECTION),
@ -1570,14 +1618,32 @@ common_gen (const char *keyparms, int algo, const char *algoelem,
return err;
}
if (keyparms2)
{
err = agent_genkey (NULL, NULL, NULL, keyparms2,
1 /* No protection */,
NULL, timestamp,
&s_key2);
if (err)
{
log_error ("agent_genkey failed for second algo: %s\n",
gpg_strerror (err) );
gcry_sexp_release (s_key);
return err;
}
}
if (common_gen_cb && common_gen_cb_parm)
{
common_gen_cb_parm->genkey_result = s_key;
common_gen_cb_parm->genkey_result2 = s_key2;
err = common_gen_cb (common_gen_cb_parm);
common_gen_cb_parm->genkey_result = NULL;
common_gen_cb_parm->genkey_result2 = NULL;
if (err)
{
gcry_sexp_release (s_key);
gcry_sexp_release (s_key2);
return err;
}
}
@ -1596,10 +1662,12 @@ common_gen (const char *keyparms, int algo, const char *algoelem,
pk->expiredate = pk->timestamp + expireval;
pk->pubkey_algo = algo;
if (algo == PUBKEY_ALGO_ECDSA
|| algo == PUBKEY_ALGO_EDDSA
|| algo == PUBKEY_ALGO_ECDH )
err = ecckey_from_sexp (pk->pkey, s_key, algo);
if (algo == PUBKEY_ALGO_KYBER)
err = ecckey_from_sexp (pk->pkey, s_key, s_key2, algo);
else if (algo == PUBKEY_ALGO_ECDSA
|| algo == PUBKEY_ALGO_EDDSA
|| algo == PUBKEY_ALGO_ECDH )
err = ecckey_from_sexp (pk->pkey, s_key, NULL, algo);
else
err = key_from_sexp (pk->pkey, s_key, "public-key", algoelem);
if (err)
@ -1610,6 +1678,7 @@ common_gen (const char *keyparms, int algo, const char *algoelem,
return err;
}
gcry_sexp_release (s_key);
gcry_sexp_release (s_key2);
pkt = xtrycalloc (1, sizeof *pkt);
if (!pkt)
@ -1675,7 +1744,7 @@ gen_elg (int algo, unsigned int nbits, KBNODE pub_root,
err = gpg_error_from_syserror ();
else
{
err = common_gen (keyparms, algo, "pgy",
err = common_gen (keyparms, NULL, algo, "pgy",
pub_root, timestamp, expireval, is_subkey,
keygen_flags, passphrase,
cache_nonce_addr, passwd_nonce_addr,
@ -1767,7 +1836,7 @@ gen_dsa (unsigned int nbits, KBNODE pub_root,
err = gpg_error_from_syserror ();
else
{
err = common_gen (keyparms, PUBKEY_ALGO_DSA, "pqgy",
err = common_gen (keyparms, NULL, PUBKEY_ALGO_DSA, "pqgy",
pub_root, timestamp, expireval, is_subkey,
keygen_flags, passphrase,
cache_nonce_addr, passwd_nonce_addr,
@ -1868,7 +1937,7 @@ gen_ecc (int algo, const char *curve, kbnode_t pub_root,
err = gpg_error_from_syserror ();
else
{
err = common_gen (keyparms, algo, "",
err = common_gen (keyparms, NULL, algo, "",
pub_root, timestamp, expireval, is_subkey,
*keygen_flags, passphrase,
cache_nonce_addr, passwd_nonce_addr,
@ -1880,6 +1949,79 @@ gen_ecc (int algo, const char *curve, kbnode_t pub_root,
}
/* Generate a dual ECC+Kyber key. Note that KEYGEN_FLAGS will be
* updated by this function to indicate the forced creation of a v5
* key. */
static gpg_error_t
gen_kyber (int algo, unsigned int nbits, const char *curve, kbnode_t pub_root,
u32 timestamp, u32 expireval, int is_subkey,
int *keygen_flags, const char *passphrase,
char **cache_nonce_addr, char **passwd_nonce_addr,
gpg_error_t (*common_gen_cb)(common_gen_cb_parm_t),
common_gen_cb_parm_t common_gen_cb_parm)
{
gpg_error_t err;
char *keyparms1;
const char *keyparms2;
log_assert (algo == PUBKEY_ALGO_KYBER);
if (nbits == 768)
keyparms2 = "(genkey(kyber768))";
else if (nbits == 1024)
keyparms2 = "(genkey(kyber1024))";
else
return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
if (!curve || !*curve)
return gpg_error (GPG_ERR_UNKNOWN_CURVE);
*keygen_flags |= KEYGEN_FLAG_CREATE_V5_KEY;
if (!strcmp (curve, "Curve25519"))
{
keyparms1 = xtryasprintf
("(genkey(ecc(curve %zu:%s)(flags djb-tweak comp%s)))",
strlen (curve), curve,
(((*keygen_flags & KEYGEN_FLAG_TRANSIENT_KEY)
&& (*keygen_flags & KEYGEN_FLAG_NO_PROTECTION))?
" transient-key" : ""));
}
else if (!strcmp (curve, "X448"))
{
keyparms1 = xtryasprintf
("(genkey(ecc(curve %zu:%s)(flags comp%s)))",
strlen (curve), curve,
(((*keygen_flags & KEYGEN_FLAG_TRANSIENT_KEY)
&& (*keygen_flags & KEYGEN_FLAG_NO_PROTECTION))?
" transient-key" : ""));
}
else /* Should we use the compressed format? Check smartcard support. */
{
keyparms1 = xtryasprintf
("(genkey(ecc(curve %zu:%s)(flags nocomp%s)))",
strlen (curve), curve,
(((*keygen_flags & KEYGEN_FLAG_TRANSIENT_KEY)
&& (*keygen_flags & KEYGEN_FLAG_NO_PROTECTION))?
" transient-key" : ""));
}
if (!keyparms1)
err = gpg_error_from_syserror ();
else
{
err = common_gen (keyparms1, keyparms2, algo, "",
pub_root, timestamp, expireval, is_subkey,
*keygen_flags, passphrase,
cache_nonce_addr, passwd_nonce_addr,
common_gen_cb, common_gen_cb_parm);
xfree (keyparms1);
}
return err;
}
/*
* Generate an RSA key.
*/
@ -1928,7 +2070,7 @@ gen_rsa (int algo, unsigned int nbits, KBNODE pub_root,
err = gpg_error_from_syserror ();
else
{
err = common_gen (keyparms, algo, "ne",
err = common_gen (keyparms, NULL, algo, "ne",
pub_root, timestamp, expireval, is_subkey,
keygen_flags, passphrase,
cache_nonce_addr, passwd_nonce_addr,
@ -2547,6 +2689,12 @@ get_keysize_range (int algo, unsigned int *min, unsigned int *max)
def=255;
break;
case PUBKEY_ALGO_KYBER:
*min = 768;
*max = 1024;
def = 768;
break;
default:
*min = opt.compliance == CO_DE_VS ? 2048: 1024;
*max = 4096;
@ -2562,45 +2710,44 @@ get_keysize_range (int algo, unsigned int *min, unsigned int *max)
static unsigned int
fixup_keysize (unsigned int nbits, int algo, int silent)
{
unsigned int orig_nbits = nbits;
if (algo == PUBKEY_ALGO_DSA && (nbits % 64))
{
nbits = ((nbits + 63) / 64) * 64;
if (!silent)
tty_printf (_("rounded up to %u bits\n"), nbits);
}
else if (algo == PUBKEY_ALGO_EDDSA)
{
if (nbits != 255 && nbits != 441)
{
if (nbits < 256)
nbits = 255;
else
nbits = 441;
if (!silent)
tty_printf (_("rounded to %u bits\n"), nbits);
}
if (nbits < 256)
nbits = 255;
else
nbits = 441;
}
else if (algo == PUBKEY_ALGO_ECDH || algo == PUBKEY_ALGO_ECDSA)
{
if (nbits != 256 && nbits != 384 && nbits != 521)
{
if (nbits < 256)
nbits = 256;
else if (nbits < 384)
nbits = 384;
else
nbits = 521;
if (!silent)
tty_printf (_("rounded to %u bits\n"), nbits);
}
if (nbits < 256)
nbits = 256;
else if (nbits < 384)
nbits = 384;
else
nbits = 521;
}
else if (algo == PUBKEY_ALGO_KYBER)
{
/* (in reality the numbers are not bits) */
if (nbits < 768)
nbits = 768;
else if (nbits > 1024)
nbits = 1024;
}
else if ((nbits % 32))
{
nbits = ((nbits + 31) / 32) * 32;
if (!silent)
tty_printf (_("rounded up to %u bits\n"), nbits );
}
if (!silent && orig_nbits != nbits)
tty_printf (_("rounded to %u bits\n"), nbits);
return nbits;
}
@ -3330,6 +3477,12 @@ do_create (int algo, unsigned int nbits, const char *curve, kbnode_t pub_root,
keygen_flags, passphrase,
cache_nonce_addr, passwd_nonce_addr,
common_gen_cb, common_gen_cb_parm);
else if (algo == PUBKEY_ALGO_KYBER)
err = gen_kyber (algo, nbits, curve,
pub_root, timestamp, expiredate, is_subkey,
keygen_flags, passphrase,
cache_nonce_addr, passwd_nonce_addr,
common_gen_cb, common_gen_cb_parm);
else if (algo == PUBKEY_ALGO_RSA)
err = gen_rsa (algo, nbits, pub_root, timestamp, expiredate, is_subkey,
*keygen_flags, passphrase,
@ -3434,6 +3587,7 @@ parse_key_parameter_part (ctrl_t ctrl,
; /* We need the flags before we can figure out the key to use. */
else if (algo)
{
/* This is one of the algos parsed above (rsa, dsa, or elg). */
if (!string[3])
size = get_keysize_range (algo, NULL, NULL);
else
@ -3443,14 +3597,15 @@ parse_key_parameter_part (ctrl_t ctrl,
return gpg_error (GPG_ERR_INV_VALUE);
}
}
else if (!ascii_strcasecmp (string, "ky768"))
else if (!ascii_strcasecmp (string, "kyber"))
{
algo = PUBKEY_ALGO_KY768_25519;
is_pqc = 1;
}
else if (!ascii_strcasecmp (string, "ky1024"))
{
algo = PUBKEY_ALGO_KY1024_448;
/* Get the curve and check that it can technically be used
* (i.e. everything except the EdXXXX curves. */
curve = openpgp_is_curve_supported ("brainpoolP384r1", &algo, NULL);
if (!curve || algo == PUBKEY_ALGO_EDDSA)
return gpg_error (GPG_ERR_UNKNOWN_CURVE);
algo = PUBKEY_ALGO_KYBER;
size = 768;
is_pqc = 1;
}
else if (!ascii_strcasecmp (string, "dil3"))
@ -3782,6 +3937,8 @@ parse_key_parameter_part (ctrl_t ctrl,
* cv25519 := ECDH using curve Curve25519.
* cv448 := ECDH using curve X448.
* nistp256:= ECDSA or ECDH using curve NIST P-256
* kyber := Kyber with the default parameters
* ky768_bp384 := Kyber-768 with BrainpoolP256r1 as second algo
*
* All strings with an unknown prefix are considered an elliptic
* curve. Curves which have no implicit algorithm require that FLAGS
@ -6495,7 +6652,7 @@ gen_card_key (int keyno, int algo, int is_primary, kbnode_t pub_root,
else if (algo == PUBKEY_ALGO_ECDSA
|| algo == PUBKEY_ALGO_EDDSA
|| algo == PUBKEY_ALGO_ECDH )
err = ecckey_from_sexp (pk->pkey, s_key, algo);
err = ecckey_from_sexp (pk->pkey, s_key, NULL, algo);
else
err = gpg_error (GPG_ERR_PUBKEY_ALGO);
gcry_sexp_release (s_key);