|
|
@@ -137,6 +137,9 @@ static bool ssh2_userauth_ki_run_prompts(struct ssh2_userauth_state *s);
|
|
|
static void ssh2_userauth_ki_write_responses(
|
|
|
struct ssh2_userauth_state *s, BinarySink *bs);
|
|
|
|
|
|
+static ptrlen workaround_rsa_sha2_cert_userauth(
|
|
|
+ struct ssh2_userauth_state *s, ptrlen id);
|
|
|
+
|
|
|
static const PacketProtocolLayerVtable ssh2_userauth_vtable = {
|
|
|
// WINSCP
|
|
|
/*.free =*/ ssh2_userauth_free,
|
|
|
@@ -2454,7 +2457,28 @@ static void ssh2_userauth_add_alg_and_publickey(
|
|
|
ppl_logevent("Sending public key with certificate from \"%s\"",
|
|
|
filename_to_str(s->detached_cert_file));
|
|
|
}
|
|
|
- put_stringz(pkt, ssh_keyalg_related_alg(certalg, pkalg)->ssh_id);
|
|
|
+ {
|
|
|
+ /* Strip off any existing certificate-nature from pkalg,
|
|
|
+ * for the case where we're replacing a cert embedded in
|
|
|
+ * the key with the detached one. The second argument of
|
|
|
+ * ssh_keyalg_related_alg is expected to be one of the
|
|
|
+ * bare key algorithms, or nothing useful will happen. */
|
|
|
+ const ssh_keyalg *pkalg_base =
|
|
|
+ pkalg->base_alg ? pkalg->base_alg : pkalg;
|
|
|
+
|
|
|
+ /* Construct an algorithm string that includes both the
|
|
|
+ * signature subtype (e.g. rsa-sha2-512) and the
|
|
|
+ * certificate-ness. Exception: in earlier versions of
|
|
|
+ * OpenSSH we don't want to do that, and must send just
|
|
|
+ * ssh-rsa-cert-... even when we're delivering a non-SHA-1
|
|
|
+ * signature. */
|
|
|
+ const ssh_keyalg *output_alg =
|
|
|
+ ssh_keyalg_related_alg(certalg, pkalg_base);
|
|
|
+ ptrlen output_id = ptrlen_from_asciz(output_alg->ssh_id);
|
|
|
+ output_id = workaround_rsa_sha2_cert_userauth(s, output_id);
|
|
|
+
|
|
|
+ put_stringpl(pkt, output_id);
|
|
|
+ }
|
|
|
put_stringpl(pkt, ptrlen_from_strbuf(s->detached_cert_blob));
|
|
|
done = true;
|
|
|
goto out;
|
|
|
@@ -2501,11 +2525,30 @@ static void ssh2_userauth_add_alg_and_publickey(
|
|
|
} // WINSCP
|
|
|
}
|
|
|
|
|
|
- /* In all other cases, just put in what we were given. */
|
|
|
+ /* In all other cases, basically just put in what we were given -
|
|
|
+ * except for the same bug workaround as above. */
|
|
|
+ alg = workaround_rsa_sha2_cert_userauth(s, alg);
|
|
|
put_stringpl(pkt, alg);
|
|
|
put_stringpl(pkt, pkblob);
|
|
|
}
|
|
|
|
|
|
+static ptrlen workaround_rsa_sha2_cert_userauth(
|
|
|
+ struct ssh2_userauth_state *s, ptrlen id)
|
|
|
+{
|
|
|
+ if (!(s->ppl.remote_bugs & BUG_RSA_SHA2_CERT_USERAUTH))
|
|
|
+ return id;
|
|
|
+/*
|
|
|
+ * No need to try to do this in a general way based on the
|
|
|
+ * relations between ssh_keyalgs; we know there are a limited
|
|
|
+ * number of affected versions of OpenSSH, so this doesn't have to
|
|
|
+ * be futureproof against later additions to the family.
|
|
|
+ */
|
|
|
+ if (ptrlen_eq_string(id, "[email protected]") ||
|
|
|
+ ptrlen_eq_string(id, "[email protected]"))
|
|
|
+ return PTRLEN_LITERAL("[email protected]");
|
|
|
+ return id;
|
|
|
+}
|
|
|
+
|
|
|
/*
|
|
|
* Helper function to add an SSH-2 signature blob to a packet. Expects
|
|
|
* to be shown the public key blob as well as the signature blob.
|
Martin Prikryl