cherry-picks from upstream (#783)

* upstream: Don't reply to PING in preauth phase or during KEX

Reported by the Qualys Security Advisory team. ok markus@

OpenBSD-Commit-ID: c656ac4abd1504389d1733d85152044b15830217

* upstream: Fix cases where error codes were not correctly set

Reported by the Qualys Security Advisory team. ok markus@

OpenBSD-Commit-ID: 7bcd4ffe0fa1e27ff98d451fb9c22f5fae6e610d

* fix error code case in Windows ssh-agent code

---------

Co-authored-by: [email protected] <[email protected]>

Author: tgauth

contrib/win32/win32compat/ssh-agent/keyagent-request.c

@@ -995,6 +995,7 @@ process_ext_session_bind(struct sshbuf* request, struct agent_connection* con)
 	/* record new key/sid */
 	if (con->nsession_ids >= AGENT_MAX_SESSION_IDS) {
 		error_f("too many session IDs recorded");
+		r = -1;
 		goto out;
 	}
 	con->session_ids = xrecallocarray(con->session_ids, con->nsession_ids,

krl.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: krl.c,v 1.59 2023/07/17 05:22:30 djm Exp $ */
+/* $OpenBSD: krl.c,v 1.60 2025/02/18 08:02:48 djm Exp $ */
 /*
  * Copyright (c) 2012 Damien Miller <[email protected]>
  *
@@ -674,6 +674,7 @@ revoked_certs_generate(struct revoked_certs *rc, struct sshbuf *buf)
 			break;
 		case KRL_SECTION_CERT_SERIAL_BITMAP:
 			if (rs->lo - bitmap_start > INT_MAX) {
+				r = SSH_ERR_INVALID_FORMAT;
 				error_f("insane bitmap gap");
 				goto out;
 			}
@@ -1059,6 +1060,7 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp)
 	}
 
 	if ((krl = ssh_krl_init()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
 		error_f("alloc failed");
 		goto out;
 	}

packet.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.315 2024/05/31 08:49:35 djm Exp $ */
+/* $OpenBSD: packet.c,v 1.318 2025/02/18 08:02:12 djm Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -1867,6 +1867,14 @@ ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
 			if ((r = sshpkt_get_string_direct(ssh, &d, &len)) != 0)
 				return r;
 			DBG(debug("Received SSH2_MSG_PING len %zu", len));
+			if (!ssh->state->after_authentication) {
+				DBG(debug("Won't reply to PING in preauth"));
+				break;
+			}
+			if (ssh_packet_is_rekeying(ssh)) {
+				DBG(debug("Won't reply to PING during KEX"));
+				break;
+			}
 			if ((r = sshpkt_start(ssh, SSH2_MSG_PONG)) != 0 ||
 			    (r = sshpkt_put_string(ssh, d, len)) != 0 ||
 			    (r = sshpkt_send(ssh)) != 0)

ssh-agent.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-agent.c,v 1.306 2024/03/09 05:12:13 djm Exp $ */
+/* $OpenBSD: ssh-agent.c,v 1.310 2025/02/18 08:02:48 djm Exp $ */
 /*
  * Author: Tatu Ylonen <[email protected]>
  * Copyright (c) 1995 Tatu Ylonen <[email protected]>, Espoo, Finland
@@ -1208,6 +1208,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp,
 	    "[email protected]") == 0) {
 		if (*dcsp != NULL) {
 			error_f("%s already set", ext_name);
+			r = SSH_ERR_INVALID_FORMAT;
 			goto out;
 		}
 		if ((r = sshbuf_froms(m, &b)) != 0) {
@@ -1217,6 +1218,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp,
 		while (sshbuf_len(b) != 0) {
 			if (*ndcsp >= AGENT_MAX_DEST_CONSTRAINTS) {
 				error_f("too many %s constraints", ext_name);
+				r = SSH_ERR_INVALID_FORMAT;
 				goto out;
 			}
 			*dcsp = xrecallocarray(*dcsp, *ndcsp, *ndcsp + 1,
@@ -1234,6 +1236,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp,
 		}
 		if (*certs != NULL) {
 			error_f("%s already set", ext_name);
+			r = SSH_ERR_INVALID_FORMAT;
 			goto out;
 		}
 		if ((r = sshbuf_get_u8(m, &v)) != 0 ||
@@ -1245,6 +1248,7 @@ parse_key_constraint_extension(struct sshbuf *m, char **sk_providerp,
 		while (sshbuf_len(b) != 0) {
 			if (*ncerts >= AGENT_MAX_EXT_CERTS) {
 				error_f("too many %s constraints", ext_name);
+				r = SSH_ERR_INVALID_FORMAT;
 				goto out;
 			}
 			*certs = xrecallocarray(*certs, *ncerts, *ncerts + 1,
@@ -1741,6 +1745,7 @@ process_ext_session_bind(SocketEntry *e)
 	/* record new key/sid */
 	if (e->nsession_ids >= AGENT_MAX_SESSION_IDS) {
 		error_f("too many session IDs recorded");
+		r = -1;
 		goto out;
 	}
 	e->session_ids = xrecallocarray(e->session_ids, e->nsession_ids,

ssh-sk-client.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-sk-client.c,v 1.12 2022/01/14 03:34:00 djm Exp $ */
+/* $OpenBSD: ssh-sk-client.c,v 1.13 2025/02/18 08:02:48 djm Exp $ */
 /*
  * Copyright (c) 2019 Google LLC
  *
@@ -570,6 +570,7 @@ sshsk_load_resident(const char *provider_path, const char *device,
 		}
 		if ((srk = calloc(1, sizeof(*srk))) == NULL) {
 			error_f("calloc failed");
+			r = SSH_ERR_ALLOC_FAIL;
 			goto out;
 		}
 		srk->key = key;
@@ -581,6 +582,7 @@ sshsk_load_resident(const char *provider_path, const char *device,
 		if ((tmp = recallocarray(srks, nsrks, nsrks + 1,
 		    sizeof(*srks))) == NULL) {
 			error_f("recallocarray keys failed");
+			r = SSH_ERR_ALLOC_FAIL;
 			goto out;
 		}
 		debug_f("srks[%zu]: %s %s uidlen %zu", nsrks,

sshconnect2.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: sshconnect2.c,v 1.373 2024/05/17 06:38:00 jsg Exp $ */
+/* $OpenBSD: sshconnect2.c,v 1.377 2025/02/18 08:02:48 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  * Copyright (c) 2008 Damien Miller.  All rights reserved.
@@ -103,7 +103,7 @@ verify_host_key_callback(struct sshkey *hostkey, struct ssh *ssh)
 	    options.required_rsa_size)) != 0)
 		fatal_r(r, "Bad server host key");
 	if (verify_host_key(xxx_host, xxx_hostaddr, hostkey,
-	    xxx_conn_info) == -1)
+	    xxx_conn_info) != 0)
 		fatal("Host key verification failed.");
 	return 0;
 }
@@ -722,6 +722,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
 		send_pubkey_telemetry("server sent unknown pkalg");
 #endif
 		debug_f("server sent unknown pkalg %s", pkalg);
+		r = SSH_ERR_INVALID_FORMAT;
 		goto done;
 	}
 	if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
@@ -738,6 +739,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
 		error("input_userauth_pk_ok: type mismatch "
 		    "for decoded key (received %d, expected %d)",
 		    key->type, pktype);
+		r = SSH_ERR_INVALID_FORMAT;
 		goto done;
 	}
 
@@ -757,6 +759,7 @@ input_userauth_pk_ok(int type, u_int32_t seq, struct ssh *ssh)
 		    SSH_FP_DEFAULT);
 		error_f("server replied with unknown key: %s %s",
 		    sshkey_type(key), fp == NULL ? "<ERROR>" : fp);
+		r = SSH_ERR_INVALID_FORMAT;
 		goto done;
 	}
 	ident = format_identity(id);

sshsig.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: sshsig.c,v 1.35 2024/03/08 22:16:32 djm Exp $ */
+/* $OpenBSD: sshsig.c,v 1.38 2025/02/18 08:02:48 djm Exp $ */
 /*
  * Copyright (c) 2019 Google LLC
  *
@@ -907,6 +907,7 @@ cert_filter_principals(const char *path, u_long linenum,
 	}
 	if ((principals = sshbuf_dup_string(nprincipals)) == NULL) {
 		error_f("buffer error");
+		r = SSH_ERR_ALLOC_FAIL;
 		goto out;
 	}
 	/* success */