Refactor EC SPKI serialization

Signed-off-by: Jethro Beekman <jethro@fortanix.com>
This commit is contained in:
Jethro Beekman 2023-05-03 13:05:33 +02:00
parent 2e662c6f97
commit 8e59ebb2e4

View File

@ -131,14 +131,14 @@ static int pk_write_ec_pubkey(unsigned char **p, unsigned char *start,
* }
*/
static int pk_write_ec_param(unsigned char **p, unsigned char *start,
mbedtls_ecp_keypair *ec)
mbedtls_ecp_group_id grp_id)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
const char *oid;
size_t oid_len;
if ((ret = mbedtls_oid_get_oid_by_ec_grp(ec->grp.id, &oid, &oid_len)) != 0) {
if ((ret = mbedtls_oid_get_oid_by_ec_grp(grp_id, &oid, &oid_len)) != 0) {
return ret;
}
@ -216,6 +216,7 @@ int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *key, unsigned char *bu
int has_par = 1;
size_t len = 0, par_len = 0, oid_len = 0;
mbedtls_pk_type_t pk_type;
mbedtls_ecp_group_id ec_grp_id;
const char *oid;
if (size == 0) {
@ -244,17 +245,7 @@ int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *key, unsigned char *bu
pk_type = mbedtls_pk_get_type(key);
#if defined(MBEDTLS_ECP_LIGHT)
if (pk_type == MBEDTLS_PK_ECKEY) {
mbedtls_ecp_keypair *ec = mbedtls_pk_ec(*key);
ret = mbedtls_oid_get_oid_by_ec_grp_algid(ec->grp.id, &oid, &oid_len);
if (ret == 0) {
has_par = 0;
} else if (ret == MBEDTLS_ERR_OID_NOT_FOUND) {
MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec));
} else {
return ret;
}
ec_grp_id = mbedtls_pk_ec(*key)->grp.id;
}
#endif /* MBEDTLS_ECP_LIGHT */
#if defined(MBEDTLS_USE_PSA_CRYPTO)
@ -264,8 +255,6 @@ int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *key, unsigned char *bu
mbedtls_svc_key_id_t key_id;
psa_ecc_family_t curve;
size_t bits;
size_t oid2_len = 0;
const char *oid2;
key_id = *((mbedtls_svc_key_id_t *) key->pk_ctx);
if (PSA_SUCCESS != psa_get_key_attributes(key_id, &attributes)) {
@ -281,18 +270,11 @@ int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *key, unsigned char *bu
return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
}
ret = mbedtls_psa_get_ecc_oid_from_id(curve, bits,
&oid2, &oid2_len);
if (ret != 0) {
ec_grp_id = mbedtls_ecc_group_of_psa(curve, bits, 0);
if (ec_grp_id == MBEDTLS_ECP_DP_NONE) {
return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
}
/* Write EC algorithm parameters; that's akin
* to pk_write_ec_param() above. */
MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_oid(&c, buf,
oid2,
oid2_len));
/* The rest of the function works as for legacy EC contexts. */
pk_type = MBEDTLS_PK_ECKEY;
} else if (PSA_KEY_TYPE_IS_RSA(key_type)) {
@ -304,6 +286,22 @@ int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *key, unsigned char *bu
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
#if defined(MBEDTLS_ECP_LIGHT)
if (pk_type == MBEDTLS_PK_ECKEY) {
/* Some groups have their own AlgorithmIdentifier OID, others are handled by mbedtls_oid_get_oid_by_pk_alg() below */
ret = mbedtls_oid_get_oid_by_ec_grp_algid(ec_grp_id, &oid, &oid_len);
if (ret == 0) {
/* Currently, none of the supported algorithms that have their own AlgorithmIdentifier OID have any parameters */
has_par = 0;
} else if (ret == MBEDTLS_ERR_OID_NOT_FOUND) {
MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec_grp_id));
} else {
return ret;
}
}
#endif /* MBEDTLS_ECP_LIGHT */
if (oid_len == 0) {
if ((ret = mbedtls_oid_get_oid_by_pk_alg(pk_type, &oid,
&oid_len)) != 0) {
@ -509,7 +507,7 @@ end_of_export:
len += pub_len;
/* parameters */
MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec));
MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec->grp.id));
MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_len(&c, buf, par_len));
MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_tag(&c, buf,