* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
-/* $OpenBSD: krl.c,v 1.56 2023/07/17 03:57:21 djm Exp $ */
+/* $OpenBSD: krl.c,v 1.57 2023/07/17 04:01:10 djm Exp $ */
#include <sys/types.h>
#include <sys/tree.h>
}
int
-ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf,
- struct sshkey **sign_keys, u_int nsign_keys)
+ssh_krl_to_blob(struct ssh_krl *krl, struct sshbuf *buf)
{
int r = SSH_ERR_INTERNAL_ERROR;
struct revoked_certs *rc;
struct revoked_blob *rb;
struct sshbuf *sect;
u_char *sblob = NULL;
- size_t slen, i;
if (krl->generated_date == 0)
krl->generated_date = time(NULL);
(r = sshbuf_put_stringb(buf, sect)) != 0)
goto out;
}
-
- for (i = 0; i < nsign_keys; i++) {
- KRL_DBG(("sig key %s", sshkey_ssh_name(sign_keys[i])));
- if ((r = sshbuf_put_u8(buf, KRL_SECTION_SIGNATURE)) != 0 ||
- (r = sshkey_puts(sign_keys[i], buf)) != 0)
- goto out;
- /* XXX support sk-* keys */
- if ((r = sshkey_sign(sign_keys[i], &sblob, &slen,
- sshbuf_ptr(buf), sshbuf_len(buf), NULL, NULL,
- NULL, 0)) != 0)
- goto out;
- KRL_DBG(("signature sig len %zu", slen));
- if ((r = sshbuf_put_string(buf, sblob, slen)) != 0)
- goto out;
- }
-
+ /* success */
r = 0;
out:
free(sblob);
return r;
}
-/* Attempt to parse a KRL, checking its signature (if any) with sign_ca_keys. */
+/* Attempt to parse a KRL */
int
-ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp,
- const struct sshkey **sign_ca_keys, size_t nsign_ca_keys)
+ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp)
{
struct sshbuf *copy = NULL, *sect = NULL;
struct ssh_krl *krl = NULL;
char timestamp[64];
- int r = SSH_ERR_INTERNAL_ERROR, sig_seen;
- struct sshkey *key = NULL, **ca_used = NULL, **tmp_ca_used;
+ int r = SSH_ERR_INTERNAL_ERROR;
u_char type;
- const u_char *blob;
- size_t i, j, sig_off, sects_off, blen, nca_used;
u_int format_version;
- nca_used = 0;
*krlp = NULL;
- if (sshbuf_len(buf) < sizeof(KRL_MAGIC) - 1 ||
- memcmp(sshbuf_ptr(buf), KRL_MAGIC, sizeof(KRL_MAGIC) - 1) != 0) {
- debug3_f("not a KRL");
- return SSH_ERR_KRL_BAD_MAGIC;
- }
- /* Take a copy of the KRL buffer so we can verify its signature later */
- if ((copy = sshbuf_fromb(buf)) == NULL) {
- r = SSH_ERR_ALLOC_FAIL;
- goto out;
+ /* KRL must begin with magic string */
+ if ((r = sshbuf_cmp(buf, 0, KRL_MAGIC, sizeof(KRL_MAGIC) - 1)) != 0) {
+ debug2_f("bad KRL magic header");
+ return r;
}
- if ((r = sshbuf_consume(copy, sizeof(KRL_MAGIC) - 1)) != 0)
- goto out;
if ((krl = ssh_krl_init()) == NULL) {
error_f("alloc failed");
goto out;
}
-
- if ((r = sshbuf_get_u32(copy, &format_version)) != 0)
+ /* Don't modify buffer */
+ if ((copy = sshbuf_fromb(buf)) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = sshbuf_consume(copy, sizeof(KRL_MAGIC) - 1)) != 0 ||
+ (r = sshbuf_get_u32(copy, &format_version)) != 0)
goto out;
if (format_version != KRL_FORMAT_VERSION) {
+ error_f("unsupported KRL format version %u", format_version);
r = SSH_ERR_INVALID_FORMAT;
goto out;
}
(r = sshbuf_get_u64(copy, &krl->generated_date)) != 0 ||
(r = sshbuf_get_u64(copy, &krl->flags)) != 0 ||
(r = sshbuf_skip_string(copy)) != 0 ||
- (r = sshbuf_get_cstring(copy, &krl->comment, NULL)) != 0)
+ (r = sshbuf_get_cstring(copy, &krl->comment, NULL)) != 0) {
+ error_fr(r, "parse KRL header");
goto out;
-
+ }
format_timestamp(krl->generated_date, timestamp, sizeof(timestamp));
debug("KRL version %llu generated at %s%s%s",
(long long unsigned)krl->krl_version, timestamp,
*krl->comment ? ": " : "", krl->comment);
- /*
- * 1st pass: verify signatures, if any. This is done to avoid
- * detailed parsing of data whose provenance is unverified.
- */
- sig_seen = 0;
- if (sshbuf_len(buf) < sshbuf_len(copy)) {
- /* Shouldn't happen */
- r = SSH_ERR_INTERNAL_ERROR;
- goto out;
- }
- sects_off = sshbuf_len(buf) - sshbuf_len(copy);
- while (sshbuf_len(copy) > 0) {
- if ((r = sshbuf_get_u8(copy, &type)) != 0 ||
- (r = sshbuf_get_string_direct(copy, &blob, &blen)) != 0)
- goto out;
- KRL_DBG(("first pass, section 0x%02x", type));
- if (type != KRL_SECTION_SIGNATURE) {
- if (sig_seen) {
- error("KRL contains non-signature section "
- "after signature");
- r = SSH_ERR_INVALID_FORMAT;
- goto out;
- }
- /* Not interested for now. */
- continue;
- }
- sig_seen = 1;
- /* First string component is the signing key */
- if ((r = sshkey_from_blob(blob, blen, &key)) != 0) {
- r = SSH_ERR_INVALID_FORMAT;
- goto out;
- }
- if (sshbuf_len(buf) < sshbuf_len(copy)) {
- /* Shouldn't happen */
- r = SSH_ERR_INTERNAL_ERROR;
- goto out;
- }
- sig_off = sshbuf_len(buf) - sshbuf_len(copy);
- /* Second string component is the signature itself */
- if ((r = sshbuf_get_string_direct(copy, &blob, &blen)) != 0) {
- r = SSH_ERR_INVALID_FORMAT;
- goto out;
- }
- /* Check signature over entire KRL up to this point */
- if ((r = sshkey_verify(key, blob, blen,
- sshbuf_ptr(buf), sig_off, NULL, 0, NULL)) != 0)
- goto out;
- /* Check if this key has already signed this KRL */
- for (i = 0; i < nca_used; i++) {
- if (sshkey_equal(ca_used[i], key)) {
- error("KRL signed more than once with "
- "the same key");
- r = SSH_ERR_INVALID_FORMAT;
- goto out;
- }
- }
- /* Record keys used to sign the KRL */
- tmp_ca_used = recallocarray(ca_used, nca_used, nca_used + 1,
- sizeof(*ca_used));
- if (tmp_ca_used == NULL) {
- r = SSH_ERR_ALLOC_FAIL;
- goto out;
- }
- ca_used = tmp_ca_used;
- ca_used[nca_used++] = key;
- key = NULL;
- }
-
- if (sshbuf_len(copy) != 0) {
- /* Shouldn't happen */
- r = SSH_ERR_INTERNAL_ERROR;
- goto out;
- }
-
- /*
- * 2nd pass: parse and load the KRL, skipping the header to the point
- * where the section start.
- */
- sshbuf_free(copy);
- if ((copy = sshbuf_fromb(buf)) == NULL) {
- r = SSH_ERR_ALLOC_FAIL;
- goto out;
- }
- if ((r = sshbuf_consume(copy, sects_off)) != 0)
- goto out;
+ /* Parse and load the KRL sections. */
while (sshbuf_len(copy) > 0) {
sshbuf_free(sect);
sect = NULL;
if ((r = sshbuf_get_u8(copy, &type)) != 0 ||
(r = sshbuf_froms(copy, §)) != 0)
goto out;
- KRL_DBG(("second pass, section 0x%02x", type));
+ KRL_DBG(("section 0x%02x", type));
switch (type) {
case KRL_SECTION_CERTIFICATES:
}
}
- /* Check that the key(s) used to sign the KRL weren't revoked */
- sig_seen = 0;
- for (i = 0; i < nca_used; i++) {
- if (ssh_krl_check_key(krl, ca_used[i]) == 0)
- sig_seen = 1;
- else {
- sshkey_free(ca_used[i]);
- ca_used[i] = NULL;
- }
- }
- if (nca_used && !sig_seen) {
- error("All keys used to sign KRL were revoked");
- r = SSH_ERR_KEY_REVOKED;
- goto out;
- }
-
- /* If we have CA keys, then verify that one was used to sign the KRL */
- if (sig_seen && nsign_ca_keys != 0) {
- sig_seen = 0;
- for (i = 0; !sig_seen && i < nsign_ca_keys; i++) {
- for (j = 0; j < nca_used; j++) {
- if (ca_used[j] == NULL)
- continue;
- if (sshkey_equal(ca_used[j], sign_ca_keys[i])) {
- sig_seen = 1;
- break;
- }
- }
- }
- if (!sig_seen) {
- r = SSH_ERR_SIGNATURE_INVALID;
- error("KRL not signed with any trusted key");
- goto out;
- }
- }
-
+ /* Success */
*krlp = krl;
r = 0;
out:
if (r != 0)
ssh_krl_free(krl);
- for (i = 0; i < nca_used; i++)
- sshkey_free(ca_used[i]);
- free(ca_used);
- sshkey_free(key);
sshbuf_free(copy);
sshbuf_free(sect);
return r;
oerrno = errno;
goto out;
}
- if ((r = ssh_krl_from_blob(krlbuf, &krl, NULL, 0)) != 0)
+ if ((r = ssh_krl_from_blob(krlbuf, &krl)) != 0)
goto out;
debug2_f("checking KRL %s", path);
r = ssh_krl_check_key(krl, key);
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