===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/kex.c,v
retrieving revision 1.181.2.1
retrieving revision 1.182
diff -u -r1.181.2.1 -r1.182
--- src/usr.bin/ssh/kex.c	2023/12/18 14:56:35	1.181.2.1
+++ src/usr.bin/ssh/kex.c	2023/10/11 04:46:29	1.182
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.c,v 1.181.2.1 2023/12/18 14:56:35 bluhm Exp $ */
+/* $OpenBSD: kex.c,v 1.182 2023/10/11 04:46:29 djm Exp $ */
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
  *
@@ -60,7 +60,7 @@
 #include "xmalloc.h"
 
 /* prototype */
-static int kex_choose_conf(struct ssh *, uint32_t seq);
+static int kex_choose_conf(struct ssh *);
 static int kex_input_newkeys(int, u_int32_t, struct ssh *);
 
 static const char * const proposal_names[PROPOSAL_MAX] = {
@@ -162,18 +162,6 @@
 	return 1;
 }
 
-/* returns non-zero if proposal contains any algorithm from algs */
-static int
-has_any_alg(const char *proposal, const char *algs)
-{
-	char *cp;
-
-	if ((cp = match_list(proposal, algs, NULL)) == NULL)
-		return 0;
-	free(cp);
-	return 1;
-}
-
 /*
  * Concatenate algorithm names, avoiding duplicates in the process.
  * Caller must free returned string.
@@ -181,7 +169,7 @@
 char *
 kex_names_cat(const char *a, const char *b)
 {
-	char *ret = NULL, *tmp = NULL, *cp, *p;
+	char *ret = NULL, *tmp = NULL, *cp, *p, *m;
 	size_t len;
 
 	if (a == NULL || *a == '\0')
@@ -198,8 +186,10 @@
 	}
 	strlcpy(ret, a, len);
 	for ((p = strsep(&cp, ",")); p && *p != '\0'; (p = strsep(&cp, ","))) {
-		if (has_any_alg(ret, p))
+		if ((m = match_list(ret, p, NULL)) != NULL) {
+			free(m);
 			continue; /* Algorithm already present */
+		}
 		if (strlcat(ret, ",", len) >= len ||
 		    strlcat(ret, p, len) >= len) {
 			free(tmp);
@@ -329,23 +319,15 @@
 	const char *defpropclient[PROPOSAL_MAX] = { KEX_CLIENT };
 	const char **defprop = ssh->kex->server ? defpropserver : defpropclient;
 	u_int i;
-	char *cp;
 
 	if (prop == NULL)
 		fatal_f("proposal missing");
 
-	/* Append EXT_INFO signalling to KexAlgorithms */
-	if (kexalgos == NULL)
-		kexalgos = defprop[PROPOSAL_KEX_ALGS];
-	if ((cp = kex_names_cat(kexalgos, ssh->kex->server ?
-	    "kex-strict-s-v00@openssh.com" :
-	    "ext-info-c,kex-strict-c-v00@openssh.com")) == NULL)
-		fatal_f("kex_names_cat");
-
 	for (i = 0; i < PROPOSAL_MAX; i++) {
 		switch(i) {
 		case PROPOSAL_KEX_ALGS:
-			prop[i] = compat_kex_proposal(ssh, cp);
+			prop[i] = compat_kex_proposal(ssh,
+			    kexalgos ? kexalgos : defprop[i]);
 			break;
 		case PROPOSAL_ENC_ALGS_CTOS:
 		case PROPOSAL_ENC_ALGS_STOC:
@@ -366,7 +348,6 @@
 			prop[i] = xstrdup(defprop[i]);
 		}
 	}
-	free(cp);
 }
 
 void
@@ -470,12 +451,7 @@
 {
 	int r;
 
-	/* If in strict mode, any unexpected message is an error */
-	if ((ssh->kex->flags & KEX_INITIAL) && ssh->kex->kex_strict) {
-		ssh_packet_disconnect(ssh, "strict KEX violation: "
-		    "unexpected packet type %u (seqnr %u)", type, seq);
-	}
-	error_f("type %u seq %u", type, seq);
+	error("kex protocol error: type %d seq %u", type, seq);
 	if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
 	    (r = sshpkt_put_u32(ssh, seq)) != 0 ||
 	    (r = sshpkt_send(ssh)) != 0)
@@ -572,7 +548,7 @@
 	if (ninfo >= 1024) {
 		error("SSH2_MSG_EXT_INFO with too many entries, expected "
 		    "<=1024, received %u", ninfo);
-		return dispatch_protocol_error(type, seq, ssh);
+		return SSH_ERR_INVALID_FORMAT;
 	}
 	for (i = 0; i < ninfo; i++) {
 		if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0)
@@ -690,7 +666,7 @@
 		error_f("no kex");
 		return SSH_ERR_INTERNAL_ERROR;
 	}
-	ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_protocol_error);
+	ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, NULL);
 	ptr = sshpkt_ptr(ssh, &dlen);
 	if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0)
 		return r;
@@ -726,7 +702,7 @@
 	if (!(kex->flags & KEX_INIT_SENT))
 		if ((r = kex_send_kexinit(ssh)) != 0)
 			return r;
-	if ((r = kex_choose_conf(ssh, seq)) != 0)
+	if ((r = kex_choose_conf(ssh)) != 0)
 		return r;
 
 	if (kex->kex_type < KEX_MAX && kex->kex[kex->kex_type] != NULL)
@@ -988,14 +964,20 @@
 	return (1);
 }
 
+/* returns non-zero if proposal contains any algorithm from algs */
 static int
-kexalgs_contains(char **peer, const char *ext)
+has_any_alg(const char *proposal, const char *algs)
 {
-	return has_any_alg(peer[PROPOSAL_KEX_ALGS], ext);
+	char *cp;
+
+	if ((cp = match_list(proposal, algs, NULL)) == NULL)
+		return 0;
+	free(cp);
+	return 1;
 }
 
 static int
-kex_choose_conf(struct ssh *ssh, uint32_t seq)
+kex_choose_conf(struct ssh *ssh)
 {
 	struct kex *kex = ssh->kex;
 	struct newkeys *newkeys;
@@ -1020,23 +1002,13 @@
 		sprop=peer;
 	}
 
-	/* Check whether peer supports ext_info/kex_strict */
-	if ((kex->flags & KEX_INITIAL) != 0) {
-		if (kex->server) {
-			kex->ext_info_c = kexalgs_contains(peer, "ext-info-c");
-			kex->kex_strict = kexalgs_contains(peer,
-			    "kex-strict-c-v00@openssh.com");
-		} else {
-			kex->kex_strict = kexalgs_contains(peer,
-			    "kex-strict-s-v00@openssh.com");
-		}
-		if (kex->kex_strict) {
-			debug3_f("will use strict KEX ordering");
-			if (seq != 0)
-				ssh_packet_disconnect(ssh,
-				    "strict KEX violation: "
-				    "KEXINIT was not the first packet");
-		}
+	/* Check whether client supports ext_info_c */
+	if (kex->server && (kex->flags & KEX_INITIAL)) {
+		char *ext;
+
+		ext = match_list("ext-info-c", peer[PROPOSAL_KEX_ALGS], NULL);
+		kex->ext_info_c = (ext != NULL);
+		free(ext);
 	}
 
 	/* Check whether client supports rsa-sha2 algorithms */
@@ -1321,7 +1293,7 @@
 	sshbuf_reset(our_version);
 	if (version_addendum != NULL && *version_addendum == '\0')
 		version_addendum = NULL;
-	if ((r = sshbuf_putf(our_version, "SSH-%d.%d-%.100s%s%s\r\n",
+	if ((r = sshbuf_putf(our_version, "SSH-%d.%d-%s%s%s\r\n",
 	    PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2, SSH_VERSION,
 	    version_addendum == NULL ? "" : " ",
 	    version_addendum == NULL ? "" : version_addendum)) != 0) {