dpp-util: use ell/asn1-private.h for ASN1 generation

ASN1 parsing will soon be required which will need some utilities in
asn1-private.h. To avoid duplication include this private header and
replace the OID's with the defined structures as well as remove the
duplicated macros.
This commit is contained in:
James Prestwood 2022-01-18 13:25:01 -08:00 committed by Denis Kenzior
parent 73cd3578d9
commit 52fafd8f5b
2 changed files with 26 additions and 25 deletions

View File

@ -142,7 +142,7 @@ ell_sources = ell/private.h \
ell/dhcp6-transport.c \
ell/acd.c
ell_shared = ell/useful.h
ell_shared = ell/useful.h ell/asn1-private.h
ell_libell_internal_la_SOURCES = $(ell_headers) $(ell_sources) $(ell_shared)
endif

View File

@ -36,6 +36,7 @@
#include "src/crypto.h"
#include "src/json.h"
#include "ell/useful.h"
#include "ell/asn1-private.h"
#include "src/ie.h"
static void append_freqs(struct l_string *uri,
@ -694,32 +695,34 @@ bool dpp_derive_ke(const uint8_t *i_nonce, const uint8_t *r_nonce,
return hkdf_expand(sha, bk, key_len, "DPP Key", ke, key_len);
}
#define ASN1_ID(class, pc, tag) (((class) << 6) | ((pc) << 5) | (tag))
#define ASN1_ID_SEQUENCE ASN1_ID(0, 1, 0x10)
#define ASN1_ID_BIT_STRING ASN1_ID(0, 0, 0x03)
#define ASN1_ID_OID ASN1_ID(0, 0, 0x06)
/*
* Values derived from OID definitions in https://www.secg.org/sec2-v2.pdf
* Appendix A.2.1
*
* 1.2.840.10045.2.1 (ecPublicKey)
*/
static uint8_t ec_oid[] = { 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01 };
static struct asn1_oid ec_oid = {
.asn1_len = 7,
.asn1 = { 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x02, 0x01 }
};
/* 1.2.840.10045.3.1.7 (prime256v1) */
static uint8_t ec_p256_oid[] = { 0x2a, 0x86, 0x48, 0xce,
0x3d, 0x03, 0x01, 0x07 };
static struct asn1_oid ec_p256_oid = {
.asn1_len = 8,
.asn1 = { 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07 }
};
/* 1.3.132.0.34 (secp384r1) */
static uint8_t ec_p384_oid[] = { 0x2B, 0x81, 0x04, 0x00, 0x22 };
static struct asn1_oid ec_p384_oid = {
.asn1_len = 5,
.asn1 = { 0x2B, 0x81, 0x04, 0x00, 0x22 }
};
uint8_t *dpp_point_to_asn1(const struct l_ecc_point *p, size_t *len_out)
{
uint8_t *asn1;
uint8_t *ptr;
uint8_t *type_oid;
size_t type_oid_len;
struct asn1_oid *key_type;
const struct l_ecc_curve *curve = l_ecc_point_get_curve(p);
ssize_t key_size = l_ecc_curve_get_scalar_bytes(curve);
uint64_t x[L_ECC_MAX_DIGITS];
@ -729,12 +732,10 @@ uint8_t *dpp_point_to_asn1(const struct l_ecc_point *p, size_t *len_out)
switch (key_size) {
case 32:
type_oid = ec_p256_oid;
type_oid_len = sizeof(ec_p256_oid);
key_type = &ec_p256_oid;
break;
case 48:
type_oid = ec_p384_oid;
type_oid_len = sizeof(ec_p384_oid);
key_type = &ec_p384_oid;
break;
default:
return NULL;
@ -744,7 +745,7 @@ uint8_t *dpp_point_to_asn1(const struct l_ecc_point *p, size_t *len_out)
if (ret < 0 || ret != key_size)
return NULL;
len = 2 + sizeof(ec_oid) + 2 + type_oid_len + 2 + key_size + 4;
len = 2 + ec_oid.asn1_len + 2 + key_type->asn1_len + 2 + key_size + 4;
/*
* Set the type to whatever avoids doing p - y when reading in the
@ -769,19 +770,19 @@ uint8_t *dpp_point_to_asn1(const struct l_ecc_point *p, size_t *len_out)
*ptr++ = ASN1_ID_SEQUENCE;
len = sizeof(ec_oid) + type_oid_len + 4;
len = ec_oid.asn1_len + key_type->asn1_len + 4;
*ptr++ = len;
*ptr++ = ASN1_ID_OID;
*ptr++ = sizeof(ec_oid);
memcpy(ptr, ec_oid, sizeof(ec_oid));
ptr += sizeof(ec_oid);
*ptr++ = ec_oid.asn1_len;
memcpy(ptr, ec_oid.asn1, ec_oid.asn1_len);
ptr += ec_oid.asn1_len;
*ptr++ = ASN1_ID_OID;
*ptr++ = type_oid_len;
memcpy(ptr, type_oid, type_oid_len);
ptr += type_oid_len;
*ptr++ = key_type->asn1_len;
memcpy(ptr, key_type->asn1, key_type->asn1_len);
ptr += key_type->asn1_len;
*ptr++ = ASN1_ID_BIT_STRING;
*ptr++ = key_size + 2;