/*
* Check if digest of one of the certificates from verified chain
* is present in the forbidden database.
* Since UEFI allows to store three types of digests
* all of them have to be checked separately.
*/
static int
check_forbidden_digests(br_x509_certificate *xcs, size_t num)
{
unsigned char sha256_digest[br_sha256_SIZE];
unsigned char sha384_digest[br_sha384_SIZE];
unsigned char sha512_digest[br_sha512_SIZE];
void *tbs;
hash_data *digest;
br_hash_compat_context ctx;
const br_hash_class *md;
size_t tbs_len, i;
int have_sha256, have_sha384, have_sha512;
if (VEC_LEN(forbidden_digests) == 0)
return (0);
/*
* Iterate through certificates, extract their To-Be-Signed section,
* and compare its digest against the ones in the forbidden database.
*/
while (num--) {
tbs = X509_to_tbs(xcs[num].data, &tbs_len);
if (tbs == NULL) {
printf("Failed to obtain TBS part of certificate\n");
return (1);
}
have_sha256 = have_sha384 = have_sha512 = 0;
for (i = 0; i < VEC_LEN(forbidden_digests); i++) {
digest = &VEC_ELT(forbidden_digests, i);
switch (digest->hash_size) {
case br_sha256_SIZE:
if (!have_sha256) {
have_sha256 = 1;
md = &br_sha256_vtable;
md->init(&ctx.vtable);
md->update(&ctx.vtable, tbs, tbs_len);
md->out(&ctx.vtable, sha256_digest);
}
if (!memcmp(sha256_digest,
digest->data,
br_sha256_SIZE))
return (1);
break;
case br_sha384_SIZE:
if (!have_sha384) {
have_sha384 = 1;
md = &br_sha384_vtable;
md->init(&ctx.vtable);
md->update(&ctx.vtable, tbs, tbs_len);
md->out(&ctx.vtable, sha384_digest);
}
if (!memcmp(sha384_digest,
digest->data,
br_sha384_SIZE))
return (1);
break;
case br_sha512_SIZE:
if (!have_sha512) {
have_sha512 = 1;
md = &br_sha512_vtable;
md->init(&ctx.vtable);
md->update(&ctx.vtable, tbs, tbs_len);
md->out(&ctx.vtable, sha512_digest);
}
if (!memcmp(sha512_digest,
digest->data,
br_sha512_SIZE))
return (1);
break;
}
}
}
return (0);
}
static int sort_axis( int axis,
int vec_size,
int vec_stride,
struct data_idx *indices,
int start,
int finish,
float *out,
int uniq,
const float fudge )
{
int i;
if (finish-start > 2)
{
qsort( indices+start, finish-start, sizeof(*indices), compare[axis] );
}
else if (indices[start].data[axis] > indices[start+1].data[axis])
{
struct data_idx tmp = indices[start];
indices[start] = indices[start+1];
indices[start+1] = tmp;
}
if (axis == vec_size-1) {
for (i = start ; i < finish ; ) {
float max = indices[i].data[axis] + fudge;
float *dest = VEC_ELT(out, vec_stride, uniq);
int j;
for (j = 0 ; j < vec_size ; j++)
dest[j] = indices[i].data[j];
for ( ; i < finish && max >= indices[i].data[axis]; i++)
indices[i].uniq_idx = uniq;
uniq++;
}
} else {
for (i = start ; i < finish ; ) {
int j = i + 1;
float max = indices[i].data[axis] + fudge;
while (j < finish && max >= indices[j].data[axis]) j++;
if (j == i+1) {
float *dest = VEC_ELT(out, vec_stride, uniq);
int k;
indices[i].uniq_idx = uniq;
for (k = 0 ; k < vec_size ; k++)
dest[k] = indices[i].data[k];
uniq++;
} else {
uniq = sort_axis( axis+1, vec_size, vec_stride,
indices, i, j, out, uniq, fudge );
}
i = j;
}
}
return uniq;
}
/**
* if we can verify the certificate chain in "certs",
* return the public key and if "xcp" is !NULL the associated
* certificate
*/
static br_x509_pkey *
verify_signer_xcs(br_x509_certificate *xcs,
size_t num,
br_name_element *elts, size_t num_elts,
anchor_list *anchors)
{
br_x509_minimal_context mc;
br_x509_certificate *xc;
size_t u;
cert_list chain = VEC_INIT;
const br_x509_pkey *tpk;
br_x509_pkey *pk;
unsigned int usages;
int err;
DEBUG_PRINTF(5, ("verify_signer: %zu certs in chain\n", num));
VEC_ADDMANY(chain, xcs, num);
if (VEC_LEN(chain) == 0) {
ve_error_set("ERROR: no/invalid certificate chain\n");
return (NULL);
}
DEBUG_PRINTF(5, ("verify_signer: %zu trust anchors\n",
VEC_LEN(*anchors)));
br_x509_minimal_init(&mc, &br_sha256_vtable,
&VEC_ELT(*anchors, 0),
VEC_LEN(*anchors));
#ifdef VE_ECDSA_SUPPORT
br_x509_minimal_set_ecdsa(&mc,
&br_ec_prime_i31, &br_ecdsa_i31_vrfy_asn1);
#endif
#ifdef VE_RSA_SUPPORT
br_x509_minimal_set_rsa(&mc, &br_rsa_i31_pkcs1_vrfy);
#endif
#if defined(UNIT_TEST) && defined(VE_DEPRECATED_RSA_SHA1_SUPPORT)
/* This is deprecated! do not enable unless you absoultely have to */
br_x509_minimal_set_hash(&mc, br_sha1_ID, &br_sha1_vtable);
#endif
br_x509_minimal_set_hash(&mc, br_sha256_ID, &br_sha256_vtable);
#ifdef VE_SHA384_SUPPORT
br_x509_minimal_set_hash(&mc, br_sha384_ID, &br_sha384_vtable);
#endif
#ifdef VE_SHA512_SUPPORT
br_x509_minimal_set_hash(&mc, br_sha512_ID, &br_sha512_vtable);
#endif
br_x509_minimal_set_name_elements(&mc, elts, num_elts);
#ifdef _STANDALONE
/*
* Clock is probably bogus so we use ve_utc.
*/
mc.days = (ve_utc / SECONDS_PER_DAY) + X509_DAYS_TO_UTC0;
mc.seconds = (ve_utc % SECONDS_PER_DAY);
#endif
mc.vtable->start_chain(&mc.vtable, NULL);
for (u = 0; u < VEC_LEN(chain); u ++) {
xc = &VEC_ELT(chain, u);
mc.vtable->start_cert(&mc.vtable, xc->data_len);
mc.vtable->append(&mc.vtable, xc->data, xc->data_len);
mc.vtable->end_cert(&mc.vtable);
switch (mc.err) {
case 0:
case BR_ERR_X509_OK:
case BR_ERR_X509_EXPIRED:
break;
default:
printf("u=%zu mc.err=%d\n", u, mc.err);
break;
}
}
err = mc.vtable->end_chain(&mc.vtable);
pk = NULL;
if (err) {
ve_error_set("Validation failed, err = %d", err);
} else {
tpk = mc.vtable->get_pkey(&mc.vtable, &usages);
if (tpk != NULL) {
pk = xpkeydup(tpk);
}
}
VEC_CLEAR(chain);
return (pk);
}
