common: Extend openpgp_oid_to_curve to return an abbreviated name.

* common/openpgp-oid.c (oidtable): Add column "abbr" and set them for
Brainpool.
(openpgp_oid_to_curve): Rename arg "canon" to "mode" and implement
mode 2.
--

For dual algorithms (PQC) we need shorter versions of brainpool to
avoid names which otherwise might be capped when printed.
This commit is contained in:
Werner Koch 2024-04-03 14:13:57 +02:00
parent 4b981e415f
commit 6c1dd3afd1
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
2 changed files with 39 additions and 14 deletions

View File

@ -43,23 +43,30 @@ static struct {
const char *oidstr; /* IETF formatted OID. */
unsigned int nbits; /* Nominal bit length of the curve. */
const char *alias; /* NULL or alternative name of the curve. */
const char *abbr; /* NULL or abbreviated name of the curve. */
int pubkey_algo; /* Required OpenPGP algo or 0 for ECDSA/ECDH. */
} oidtable[] = {
{ "Curve25519", "1.3.6.1.4.1.3029.1.5.1", 255, "cv25519", PUBKEY_ALGO_ECDH },
{ "Ed25519", "1.3.6.1.4.1.11591.15.1", 255, "ed25519", PUBKEY_ALGO_EDDSA },
{ "Curve25519", "1.3.101.110", 255, "cv25519", PUBKEY_ALGO_ECDH },
{ "Ed25519", "1.3.101.112", 255, "ed25519", PUBKEY_ALGO_EDDSA },
{ "X448", "1.3.101.111", 448, "cv448", PUBKEY_ALGO_ECDH },
{ "Ed448", "1.3.101.113", 456, "ed448", PUBKEY_ALGO_EDDSA },
{ "Curve25519", "1.3.6.1.4.1.3029.1.5.1", 255, "cv25519", NULL,
PUBKEY_ALGO_ECDH },
{ "Ed25519", "1.3.6.1.4.1.11591.15.1", 255, "ed25519", NULL,
PUBKEY_ALGO_EDDSA },
{ "Curve25519", "1.3.101.110", 255, "cv25519", NULL,
PUBKEY_ALGO_ECDH },
{ "Ed25519", "1.3.101.112", 255, "ed25519", NULL,
PUBKEY_ALGO_EDDSA },
{ "X448", "1.3.101.111", 448, "cv448", NULL,
PUBKEY_ALGO_ECDH },
{ "Ed448", "1.3.101.113", 456, "ed448", NULL,
PUBKEY_ALGO_EDDSA },
{ "NIST P-256", "1.2.840.10045.3.1.7", 256, "nistp256" },
{ "NIST P-384", "1.3.132.0.34", 384, "nistp384" },
{ "NIST P-521", "1.3.132.0.35", 521, "nistp521" },
{ "brainpoolP256r1", "1.3.36.3.3.2.8.1.1.7", 256 },
{ "brainpoolP384r1", "1.3.36.3.3.2.8.1.1.11", 384 },
{ "brainpoolP512r1", "1.3.36.3.3.2.8.1.1.13", 512 },
{ "brainpoolP256r1", "1.3.36.3.3.2.8.1.1.7", 256, NULL, "bp256" },
{ "brainpoolP384r1", "1.3.36.3.3.2.8.1.1.11", 384, NULL, "bp384" },
{ "brainpoolP512r1", "1.3.36.3.3.2.8.1.1.13", 512, NULL, "bp512" },
{ "secp256k1", "1.3.132.0.10", 256 },
@ -477,10 +484,20 @@ openpgp_curve_to_oid (const char *name, unsigned int *r_nbits, int *r_algo)
/* Map an OpenPGP OID to the Libgcrypt curve name. Returns NULL for
* unknown curve names. Unless CANON is set we prefer an alias name
* here which is more suitable for printing. */
* unknown curve names. MODE defines which version of the curve name
* is returned. For example:
*
* | OID | mode=0 | mode=1 | mode=2 |
* |----------------------+-----------------+-----------------+----------|
* | 1.2.840.10045.3.1.7 | nistp256 | NIST P-256 | nistp256 |
* | 1.3.36.3.3.2.8.1.1.7 | brainpoolP256r1 | brainpoolP256r1 | bp256 |
*
* Thus mode 0 returns the name as commonly used gpg, mode 1 returns
* the canonical name, and mode 2 prefers an abbreviated name over the
* commonly used name.
*/
const char *
openpgp_oid_to_curve (const char *oidstr, int canon)
openpgp_oid_to_curve (const char *oidstr, int mode)
{
int i;
@ -489,7 +506,15 @@ openpgp_oid_to_curve (const char *oidstr, int canon)
for (i=0; oidtable[i].name; i++)
if (!strcmp (oidtable[i].oidstr, oidstr))
return !canon && oidtable[i].alias? oidtable[i].alias : oidtable[i].name;
{
if (mode == 2)
{
if (oidtable[i].abbr)
return oidtable[i].abbr;
mode = 0; /* No abbreviation - fallback to mode 0. */
}
return !mode && oidtable[i].alias? oidtable[i].alias : oidtable[i].name;
}
return NULL;
}

View File

@ -229,7 +229,7 @@ int openpgp_oid_is_cv448 (gcry_mpi_t a);
int openpgp_oid_is_ed448 (gcry_mpi_t a);
const char *openpgp_curve_to_oid (const char *name,
unsigned int *r_nbits, int *r_algo);
const char *openpgp_oid_to_curve (const char *oid, int canon);
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);
const char *openpgp_is_curve_supported (const char *name,