Download raw body.
rpki-client: parse SIA also for EE certs
This depends on "rpki-client: cert_check_purpose tweaks"
https://marc.info/?l=openbsd-tech&m=175033387518906&w=2
Parse SIA extensions for EE certificates. There should only be (perhaps
multiple) id-ad-signed-Object access methods, but unfortunately the
ecosystem is polluted with currently roughly 50k EE certs containing
an rpkiNotify access method. So we need to continue to tolerate that.
Rename sbgp_sia() (whose name doesn't make much sense) to cert_ca_sia().
Add cert_ee_sia() which is similar to cert_ca_sia() and x509_get_sia().
There's duplication of code and work because of the latter. I am going
to remove x509_get_sia() further down the road, which will make use of
the new cert->signedobj member. Since it's only for EE certs, there's
no need to transfer it over the pipes.
Likewise, cert_parse_ee_cert() and cert_parse_pre() will see quite a bit
of deduplication.
diff --git a/usr.sbin/rpki-client/cert.c b/usr.sbin/rpki-client/cert.c
index af9c34e26fc..c4c55d505d0 100644
--- a/usr.sbin/rpki-client/cert.c
+++ b/usr.sbin/rpki-client/cert.c
@@ -34,6 +34,7 @@ extern ASN1_OBJECT *bgpsec_oid; /* id-kp-bgpsec-router Key Purpose */
extern ASN1_OBJECT *certpol_oid; /* id-cp-ipAddr-asNumber cert policy */
extern ASN1_OBJECT *carepo_oid; /* 1.3.6.1.5.5.7.48.5 (caRepository) */
extern ASN1_OBJECT *manifest_oid; /* 1.3.6.1.5.5.7.48.10 (rpkiManifest) */
+extern ASN1_OBJECT *signedobj_oid; /* 1.3.6.1.5.5.7.48.11 (signedObject) */
extern ASN1_OBJECT *notify_oid; /* 1.3.6.1.5.5.7.48.13 (rpkiNotify) */
int certid = TALSZ_MAX;
@@ -505,7 +506,7 @@ sbgp_ipaddrblk(const char *fn, struct cert *cert, X509_EXTENSION *ext)
* Returns zero on failure, non-zero on success.
*/
static int
-sbgp_sia(const char *fn, struct cert *cert, X509_EXTENSION *ext)
+cert_ca_sia(const char *fn, struct cert *cert, X509_EXTENSION *ext)
{
AUTHORITY_INFO_ACCESS *sia = NULL;
ACCESS_DESCRIPTION *ad;
@@ -638,6 +639,125 @@ sbgp_sia(const char *fn, struct cert *cert, X509_EXTENSION *ext)
return rc;
}
+/*
+ * Parse "Subject Information Access" extension for an EE cert,
+ * RFC 6487, section 4.8.8.2 and RFC 8182, section 3.2.
+ * Returns zero on failure, non-zero on success.
+ */
+static int
+cert_ee_sia(const char *fn, struct cert *cert, X509_EXTENSION *ext)
+{
+ AUTHORITY_INFO_ACCESS *sia = NULL;
+ ACCESS_DESCRIPTION *ad;
+ ASN1_OBJECT *oid;
+ char *signedobj = NULL;
+ int i, rc = 0;
+
+ assert(cert->signedobj == NULL);
+
+ if (X509_EXTENSION_get_critical(ext)) {
+ warnx("%s: RFC 6487 section 4.8.8: SIA: "
+ "extension not non-critical", fn);
+ goto out;
+ }
+
+ if ((sia = X509V3_EXT_d2i(ext)) == NULL) {
+ warnx("%s: RFC 6487 section 4.8.8: SIA: failed extension parse",
+ fn);
+ goto out;
+ }
+
+ for (i = 0; i < sk_ACCESS_DESCRIPTION_num(sia); i++) {
+ ad = sk_ACCESS_DESCRIPTION_value(sia, i);
+
+ oid = ad->method;
+
+ /*
+ * XXX: RFC 6487 4.8.8.2 states that the accessMethod MUST be
+ * signedObject. However, rpkiNotify accessMethods currently
+ * exist in the wild. Consider removing this special case.
+ * See also https://www.rfc-editor.org/errata/eid7239.
+ */
+ if (OBJ_cmp(oid, notify_oid) == 0) {
+ if (verbose > 1)
+ warnx("%s: RFC 6487 section 4.8.8.2: SIA should"
+ " not contain rpkiNotify accessMethod", fn);
+ continue;
+ } else if (OBJ_cmp(oid, signedobj_oid) == 0) {
+ if (!x509_location(fn, "SIA: signedObject",
+ ad->location, &signedobj))
+ goto out;
+ if (cert->signedobj == NULL && strncasecmp(signedobj,
+ RSYNC_PROTO, RSYNC_PROTO_LEN) == 0) {
+ cert->signedobj = signedobj;
+ signedobj = NULL;
+ continue;
+ }
+ if (verbose)
+ warnx("%s: RFC 6487 section 4.8.8: SIA: "
+ "ignoring location %s", fn, signedobj);
+ free(signedobj);
+ signedobj = NULL;
+ } else {
+ char buf[128];
+
+ OBJ_obj2txt(buf, sizeof(buf), oid, 0);
+ warnx("%s: RFC 6487 section 4.8.8.1: unexpected"
+ " accessMethod: %s", fn, buf);
+ goto out;
+ }
+ }
+
+ if (cert->signedobj == NULL) {
+ warnx("%s: RFC 6487 section 4.8.8: SIA: no signedObject", fn);
+ goto out;
+ }
+
+ if (filemode) {
+ if (rtype_from_file_extension(cert->signedobj) !=
+ rtype_from_file_extension(fn)) {
+ warnx("%s: SIA signedObject contains unexpected "
+ "filename extension", fn);
+ goto out;
+ }
+ } else {
+ const char *p = cert->signedobj + RSYNC_PROTO_LEN;
+ size_t fnlen, plen;
+
+ fnlen = strlen(fn);
+ plen = strlen(p);
+
+ if (fnlen < plen || strcmp(p, fn + fnlen - plen) != 0) {
+ warnx("%s: mismatch between pathname and SIA (%s)",
+ fn, cert->signedobj);
+ goto out;
+ }
+ }
+
+ rc = 1;
+ out:
+ AUTHORITY_INFO_ACCESS_free(sia);
+ return rc;
+}
+
+static int
+cert_sia(const char *fn, struct cert *cert, X509_EXTENSION *ext)
+{
+ switch (cert->purpose) {
+ case CERT_PURPOSE_TA:
+ case CERT_PURPOSE_CA:
+ return cert_ca_sia(fn, cert, ext);
+ case CERT_PURPOSE_EE:
+ return cert_ee_sia(fn, cert, ext);
+ case CERT_PURPOSE_BGPSEC_ROUTER:
+ warnx("%s: RFC 8209, 3.1.3.3, SIA MUST be omitted from "
+ "BGPSec router certs", fn);
+ return 0;
+ default:
+ abort();
+ }
+}
+
/*
* Parse the certificate policies extension and check that it follows RFC 7318.
* Returns zero on failure, non-zero on success.
@@ -922,6 +1042,12 @@ cert_parse_ee_cert(const char *fn, int talid, X509 *x)
goto out;
}
+ index = X509_get_ext_by_NID(x, NID_sinfo_access, -1);
+ if ((ext = X509_get_ext(x, index)) != NULL) {
+ if (!cert_sia(fn, cert, ext))
+ goto out;
+ }
+
index = X509_get_ext_by_NID(x, NID_sbgp_ipAddrBlock, -1);
if ((ext = X509_get_ext(x, index)) != NULL) {
if (!sbgp_ipaddrblk(fn, cert, ext))
@@ -1074,11 +1200,7 @@ cert_parse_pre(const char *fn, const unsigned char *der, size_t len)
case NID_sinfo_access:
if (sia++ > 0)
goto dup;
- /*
- * This will fail for BGPsec certs, but they must omit
- * this extension anyway (RFC 8209, section 3.1.3.3).
- */
- if (!sbgp_sia(fn, cert, ext))
+ if (!cert_sia(fn, cert, ext))
goto out;
break;
case NID_certificate_policies:
@@ -1162,11 +1284,6 @@ cert_parse_pre(const char *fn, const unsigned char *der, size_t len)
goto out;
}
}
- if (sia) {
- warnx("%s: unexpected SIA extension in BGPsec cert",
- fn);
- goto out;
- }
break;
case CERT_PURPOSE_EE:
warnx("%s: unexpected EE cert", fn);
@@ -1316,6 +1433,7 @@ cert_free(struct cert *p)
free(p->path);
free(p->mft);
free(p->notify);
+ free(p->signedobj);
free(p->ips);
free(p->ases);
free(p->aia);
diff --git a/usr.sbin/rpki-client/extern.h b/usr.sbin/rpki-client/extern.h
index 23edd1fc602..9e2c64c4e6d 100644
--- a/usr.sbin/rpki-client/extern.h
+++ b/usr.sbin/rpki-client/extern.h
@@ -134,6 +134,7 @@ struct cert {
char *mft; /* manifest (rsync:// uri) */
char *notify; /* RRDP notify (https:// uri) */
char *crl; /* CRL location (rsync:// or NULL) */
+ char *signedobj; /* rsync access location for EE certs. */
char *aia; /* AIA (or NULL, for trust anchor) */
char *aki; /* AKI (or NULL, for trust anchor) */
char *ski; /* SKI */
rpki-client: parse SIA also for EE certs