upstream: allow key revocation by SHA256 hash and allow ssh-keygen
to create KRLs using SHA256/base64 key fingerprints; ok markus@
OpenBSD-Commit-ID: a0590fd34e7f1141f2873ab3acc57442560e6a94
diff --git a/krl.c b/krl.c
index 3791532..8e2d5d5 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 1.41 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: krl.c,v 1.42 2018/09/12 01:21:34 djm Exp $ */
#include "includes.h"
@@ -96,6 +96,7 @@
char *comment;
struct revoked_blob_tree revoked_keys;
struct revoked_blob_tree revoked_sha1s;
+ struct revoked_blob_tree revoked_sha256s;
struct revoked_certs_list revoked_certs;
};
@@ -136,6 +137,7 @@
return NULL;
RB_INIT(&krl->revoked_keys);
RB_INIT(&krl->revoked_sha1s);
+ RB_INIT(&krl->revoked_sha256s);
TAILQ_INIT(&krl->revoked_certs);
return krl;
}
@@ -178,6 +180,11 @@
free(rb->blob);
free(rb);
}
+ RB_FOREACH_SAFE(rb, revoked_blob_tree, &krl->revoked_sha256s, trb) {
+ RB_REMOVE(revoked_blob_tree, &krl->revoked_sha256s, rb);
+ free(rb->blob);
+ free(rb);
+ }
TAILQ_FOREACH_SAFE(rc, &krl->revoked_certs, entry, trc) {
TAILQ_REMOVE(&krl->revoked_certs, rc, entry);
revoked_certs_free(rc);
@@ -408,25 +415,47 @@
return revoke_blob(&krl->revoked_keys, blob, len);
}
-int
-ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const struct sshkey *key)
+static int
+revoke_by_hash(struct revoked_blob_tree *target, const u_char *p, size_t len)
{
u_char *blob;
- size_t len;
int r;
- debug3("%s: revoke type %s by sha1", __func__, sshkey_type(key));
- if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA1,
- &blob, &len)) != 0)
+ /* need to copy hash, as revoke_blob steals ownership */
+ if ((blob = malloc(len)) == NULL)
+ return SSH_ERR_SYSTEM_ERROR;
+ memcpy(blob, p, len);
+ if ((r = revoke_blob(target, blob, len)) != 0) {
+ free(blob);
return r;
- return revoke_blob(&krl->revoked_sha1s, blob, len);
+ }
+ return 0;
+}
+
+int
+ssh_krl_revoke_key_sha1(struct ssh_krl *krl, const u_char *p, size_t len)
+{
+ debug3("%s: revoke by sha1", __func__);
+ if (len != 20)
+ return SSH_ERR_INVALID_FORMAT;
+ return revoke_by_hash(&krl->revoked_sha1s, p, len);
+}
+
+int
+ssh_krl_revoke_key_sha256(struct ssh_krl *krl, const u_char *p, size_t len)
+{
+ debug3("%s: revoke by sha256", __func__);
+ if (len != 32)
+ return SSH_ERR_INVALID_FORMAT;
+ return revoke_by_hash(&krl->revoked_sha256s, p, len);
}
int
ssh_krl_revoke_key(struct ssh_krl *krl, const struct sshkey *key)
{
+ /* XXX replace with SHA256? */
if (!sshkey_is_cert(key))
- return ssh_krl_revoke_key_sha1(krl, key);
+ return ssh_krl_revoke_key_explicit(krl, key);
if (key->cert->serial == 0) {
return ssh_krl_revoke_cert_by_key_id(krl,
@@ -762,6 +791,18 @@
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
+ sshbuf_reset(sect);
+ RB_FOREACH(rb, revoked_blob_tree, &krl->revoked_sha256s) {
+ KRL_DBG(("%s: hash len %zu ", __func__, rb->len));
+ if ((r = sshbuf_put_string(sect, rb->blob, rb->len)) != 0)
+ goto out;
+ }
+ if (sshbuf_len(sect) != 0) {
+ if ((r = sshbuf_put_u8(buf,
+ KRL_SECTION_FINGERPRINT_SHA256)) != 0 ||
+ (r = sshbuf_put_stringb(buf, sect)) != 0)
+ goto out;
+ }
for (i = 0; i < nsign_keys; i++) {
KRL_DBG(("%s: signature key %s", __func__,
@@ -914,6 +955,29 @@
return r;
}
+static int
+blob_section(struct sshbuf *sect, struct revoked_blob_tree *target_tree,
+ size_t expected_len)
+{
+ u_char *rdata = NULL;
+ size_t rlen = 0;
+ int r;
+
+ while (sshbuf_len(sect) > 0) {
+ if ((r = sshbuf_get_string(sect, &rdata, &rlen)) != 0)
+ return r;
+ if (expected_len != 0 && rlen != expected_len) {
+ error("%s: bad length", __func__);
+ free(rdata);
+ return SSH_ERR_INVALID_FORMAT;
+ }
+ if ((r = revoke_blob(target_tree, rdata, rlen)) != 0) {
+ free(rdata);
+ return r;
+ }
+ }
+ return 0;
+}
/* Attempt to parse a KRL, checking its signature (if any) with sign_ca_keys. */
int
@@ -925,9 +989,9 @@
char timestamp[64];
int r = SSH_ERR_INTERNAL_ERROR, sig_seen;
struct sshkey *key = NULL, **ca_used = NULL, **tmp_ca_used;
- u_char type, *rdata = NULL;
+ u_char type;
const u_char *blob;
- size_t i, j, sig_off, sects_off, rlen, blen, nca_used;
+ size_t i, j, sig_off, sects_off, blen, nca_used;
u_int format_version;
nca_used = 0;
@@ -1068,24 +1132,19 @@
goto out;
break;
case KRL_SECTION_EXPLICIT_KEY:
+ if ((r = blob_section(sect,
+ &krl->revoked_keys, 0)) != 0)
+ goto out;
+ break;
case KRL_SECTION_FINGERPRINT_SHA1:
- while (sshbuf_len(sect) > 0) {
- if ((r = sshbuf_get_string(sect,
- &rdata, &rlen)) != 0)
- goto out;
- if (type == KRL_SECTION_FINGERPRINT_SHA1 &&
- rlen != 20) {
- error("%s: bad SHA1 length", __func__);
- r = SSH_ERR_INVALID_FORMAT;
- goto out;
- }
- if ((r = revoke_blob(
- type == KRL_SECTION_EXPLICIT_KEY ?
- &krl->revoked_keys : &krl->revoked_sha1s,
- rdata, rlen)) != 0)
- goto out;
- rdata = NULL; /* revoke_blob frees rdata */
- }
+ if ((r = blob_section(sect,
+ &krl->revoked_sha1s, 20)) != 0)
+ goto out;
+ break;
+ case KRL_SECTION_FINGERPRINT_SHA256:
+ if ((r = blob_section(sect,
+ &krl->revoked_sha256s, 32)) != 0)
+ goto out;
break;
case KRL_SECTION_SIGNATURE:
/* Handled above, but still need to stay in synch */
@@ -1150,7 +1209,6 @@
for (i = 0; i < nca_used; i++)
sshkey_free(ca_used[i]);
free(ca_used);
- free(rdata);
sshkey_free(key);
sshbuf_free(copy);
sshbuf_free(sect);
@@ -1210,6 +1268,16 @@
KRL_DBG(("%s: revoked by key SHA1", __func__));
return SSH_ERR_KEY_REVOKED;
}
+ memset(&rb, 0, sizeof(rb));
+ if ((r = sshkey_fingerprint_raw(key, SSH_DIGEST_SHA256,
+ &rb.blob, &rb.len)) != 0)
+ return r;
+ erb = RB_FIND(revoked_blob_tree, &krl->revoked_sha256s, &rb);
+ free(rb.blob);
+ if (erb != NULL) {
+ KRL_DBG(("%s: revoked by key SHA256", __func__));
+ return SSH_ERR_KEY_REVOKED;
+ }
/* Next, explicit keys */
memset(&rb, 0, sizeof(rb));