upstream commit

permit KRLs that revoke certificates by serial number or
 key ID without scoping to a particular CA; ok markus@

1 files changed, 64 insertions, 38 deletions

diff --git a/krl.c b/krl.c
index 3fe29c8b1..4bbaa2080 100644
--- a/krl.c
+++ b/krl.c
@@ -14,7 +14,7 @@
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $OpenBSD: krl.c,v 1.30 2015/01/26 02:59:11 djm Exp $ */
+/* $OpenBSD: krl.c,v 1.31 2015/01/30 01:10:33 djm Exp $ */
 
 #include "includes.h"
 
@@ -156,8 +156,7 @@ revoked_certs_free(struct revoked_certs *rc)
                 free(rki->key_id);
                 free(rki);
         }
-        if (rc->ca_key != NULL)
-                sshkey_free(rc->ca_key);
+        sshkey_free(rc->ca_key);
 }
 
 void
@@ -214,7 +213,8 @@ revoked_certs_for_ca_key(struct ssh_krl *krl, const struct sshkey *ca_key,
 
         *rcp = NULL;
         TAILQ_FOREACH(rc, &krl->revoked_certs, entry) {
-                if (sshkey_equal(rc->ca_key, ca_key)) {
+                if ((ca_key == NULL && rc->ca_key == NULL) ||
+                    sshkey_equal(rc->ca_key, ca_key)) {
                         *rcp = rc;
                         return 0;
                 }
@@ -224,14 +224,17 @@ revoked_certs_for_ca_key(struct ssh_krl *krl, const struct sshkey *ca_key,
         /* If this CA doesn't exist in the list then add it now */
         if ((rc = calloc(1, sizeof(*rc))) == NULL)
                 return SSH_ERR_ALLOC_FAIL;
-        if ((r = sshkey_from_private(ca_key, &rc->ca_key)) != 0) {
+        if (ca_key == NULL)
+                rc->ca_key = NULL;
+        else if ((r = sshkey_from_private(ca_key, &rc->ca_key)) != 0) {
                 free(rc);
                 return r;
         }
         RB_INIT(&rc->revoked_serials);
         RB_INIT(&rc->revoked_key_ids);
         TAILQ_INSERT_TAIL(&krl->revoked_certs, rc, entry);
-        KRL_DBG(("%s: new CA %s", __func__, sshkey_type(ca_key)));
+        KRL_DBG(("%s: new CA %s", __func__,
+            ca_key == NULL ? "*" : sshkey_type(ca_key)));
         *rcp = rc;
         return 0;
 }
@@ -554,9 +557,15 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
         if ((sect = sshbuf_new()) == NULL)
                 return SSH_ERR_ALLOC_FAIL;
 
-        /* Store the header: CA scope key, reserved */
-        if ((r = sshkey_puts(rc->ca_key, buf)) != 0 ||
-            (r = sshbuf_put_string(buf, NULL, 0)) != 0)
+        /* Store the header: optional CA scope key, reserved */
+        if (rc->ca_key == NULL) {
+                if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
+                        goto out;
+        } else {
+                if ((r = sshkey_puts(rc->ca_key, buf)) != 0)
+                        goto out;
+        }
+        if ((r = sshbuf_put_string(buf, NULL, 0)) != 0)
                 goto out;
 
         /* Store the revoked serials.  */
@@ -813,7 +822,7 @@ parse_revoked_certs(struct sshbuf *buf, struct ssh_krl *krl)
         if ((r = sshbuf_get_string_direct(buf, &blob, &blen)) != 0 ||
             (r = sshbuf_skip_string(buf)) != 0)
                 goto out;
-        if ((r = sshkey_from_blob(blob, blen, &ca_key)) != 0)
+        if (blen != 0 && (r = sshkey_from_blob(blob, blen, &ca_key)) != 0)
                 goto out;
 
         while (sshbuf_len(buf) > 0) {
@@ -1154,13 +1163,45 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp,
         return r;
 }
 
+/* Checks certificate serial number and key ID revocation */
+static int
+is_cert_revoked(const struct sshkey *key, struct revoked_certs *rc)
+{
+        struct revoked_serial rs, *ers;
+        struct revoked_key_id rki, *erki;
+
+        /* Check revocation by cert key ID */
+        memset(&rki, 0, sizeof(rki));
+        rki.key_id = key->cert->key_id;
+        erki = RB_FIND(revoked_key_id_tree, &rc->revoked_key_ids, &rki);
+        if (erki != NULL) {
+                KRL_DBG(("%s: revoked by key ID", __func__));
+                return SSH_ERR_KEY_REVOKED;
+        }
+
+        /*
+         * Legacy cert formats lack serial numbers. Zero serials numbers
+         * are ignored (it's the default when the CA doesn't specify one).
+         */
+        if (sshkey_cert_is_legacy(key) || key->cert->serial == 0)
+                return 0;
+
+        memset(&rs, 0, sizeof(rs));
+        rs.lo = rs.hi = key->cert->serial;
+        ers = RB_FIND(revoked_serial_tree, &rc->revoked_serials, &rs);
+        if (ers != NULL) {
+                KRL_DBG(("%s: revoked serial %llu matched %llu:%llu", __func__,
+                    key->cert->serial, ers->lo, ers->hi));
+                return SSH_ERR_KEY_REVOKED;
+        }
+        return 0;
+}
+
 /* Checks whether a given key/cert is revoked. Does not check its CA */
 static int
 is_key_revoked(struct ssh_krl *krl, const struct sshkey *key)
 {
         struct revoked_blob rb, *erb;
-        struct revoked_serial rs, *ers;
-        struct revoked_key_id rki, *erki;
         struct revoked_certs *rc;
         int r;
 
@@ -1190,37 +1231,22 @@ is_key_revoked(struct ssh_krl *krl, const struct sshkey *key)
         if (!sshkey_is_cert(key))
                 return 0;
 
-        /* Check cert revocation */
+        /* Check cert revocation for the specified CA */
         if ((r = revoked_certs_for_ca_key(krl, key->cert->signature_key,
             &rc, 0)) != 0)
                 return r;
-        if (rc == NULL)
-                return 0; /* No entry for this CA */
-
-        /* Check revocation by cert key ID */
-        memset(&rki, 0, sizeof(rki));
-        rki.key_id = key->cert->key_id;
-        erki = RB_FIND(revoked_key_id_tree, &rc->revoked_key_ids, &rki);
-        if (erki != NULL) {
-                KRL_DBG(("%s: revoked by key ID", __func__));
-                return SSH_ERR_KEY_REVOKED;
+        if (rc != NULL) {
+                if ((r = is_cert_revoked(key, rc)) != 0)
+                        return r;
         }
-
-        /*
-         * Legacy cert formats lack serial numbers. Zero serials numbers
-         * are ignored (it's the default when the CA doesn't specify one).
-         */
-        if (sshkey_cert_is_legacy(key) || key->cert->serial == 0)
-                return 0;
-
-        memset(&rs, 0, sizeof(rs));
-        rs.lo = rs.hi = key->cert->serial;
-        ers = RB_FIND(revoked_serial_tree, &rc->revoked_serials, &rs);
-        if (ers != NULL) {
-                KRL_DBG(("%s: revoked serial %llu matched %llu:%llu", __func__,
-                    key->cert->serial, ers->lo, ers->hi));
-                return SSH_ERR_KEY_REVOKED;
+        /* Check cert revocation for the wildcard CA */
+        if ((r = revoked_certs_for_ca_key(krl, NULL, &rc, 0)) != 0)
+                return r;
+        if (rc != NULL) {
+                if ((r = is_cert_revoked(key, rc)) != 0)
+                        return r;
         }
+
         KRL_DBG(("%s: %llu no match", __func__, key->cert->serial));
         return 0;
 }