- djm@cvs.openbsd.org 2014/07/03 06:39:19
[ssh.c ssh_config.5]
Add a %C escape sequence for LocalCommand and ControlPath that expands
to a unique identifer based on a has of the tuple of (local host,
remote user, hostname, port).
Helps avoid exceeding sockaddr_un's miserly pathname limits for mux
control paths.
bz#2220, based on patch from mancha1 AT zoho.com; ok markus@
diff --git a/ssh.c b/ssh.c
index 6625557..54f1dbd 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.404 2014/06/27 16:41:56 markus Exp $ */
+/* $OpenBSD: ssh.c,v 1.405 2014/07/03 06:39:19 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -85,6 +85,7 @@
#include "canohost.h"
#include "compat.h"
#include "cipher.h"
+#include "digest.h"
#include "packet.h"
#include "buffer.h"
#include "channels.h"
@@ -424,6 +425,9 @@
extern char *optarg;
Forward fwd;
struct addrinfo *addrs = NULL;
+ struct ssh_digest_ctx *md;
+ u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
+ char *conn_hash_hex;
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
@@ -1002,12 +1006,29 @@
shorthost[strcspn(thishost, ".")] = '\0';
snprintf(portstr, sizeof(portstr), "%d", options.port);
+ if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL ||
+ ssh_digest_update(md, thishost, strlen(thishost)) < 0 ||
+ ssh_digest_update(md, host, strlen(host)) < 0 ||
+ ssh_digest_update(md, portstr, strlen(portstr)) < 0 ||
+ ssh_digest_update(md, options.user, strlen(options.user)) < 0 ||
+ ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0)
+ fatal("%s: mux digest failed", __func__);
+ ssh_digest_free(md);
+ conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1));
+
if (options.local_command != NULL) {
debug3("expanding LocalCommand: %s", options.local_command);
cp = options.local_command;
- options.local_command = percent_expand(cp, "d", pw->pw_dir,
- "h", host, "l", thishost, "n", host_arg, "r", options.user,
- "p", portstr, "u", pw->pw_name, "L", shorthost,
+ options.local_command = percent_expand(cp,
+ "C", conn_hash_hex,
+ "L", shorthost,
+ "d", pw->pw_dir,
+ "h", host,
+ "l", thishost,
+ "n", host_arg,
+ "p", portstr,
+ "r", options.user,
+ "u", pw->pw_name,
(char *)NULL);
debug3("expanded LocalCommand: %s", options.local_command);
free(cp);
@@ -1017,12 +1038,20 @@
cp = tilde_expand_filename(options.control_path,
original_real_uid);
free(options.control_path);
- options.control_path = percent_expand(cp, "h", host,
- "l", thishost, "n", host_arg, "r", options.user,
- "p", portstr, "u", pw->pw_name, "L", shorthost,
+ options.control_path = percent_expand(cp,
+ "C", conn_hash_hex,
+ "L", shorthost,
+ "h", host,
+ "l", thishost,
+ "n", host_arg,
+ "p", portstr,
+ "r", options.user,
+ "u", pw->pw_name,
(char *)NULL);
free(cp);
}
+ free(conn_hash_hex);
+
if (muxclient_command != 0 && options.control_path == NULL)
fatal("No ControlPath specified for \"-O\" command");
if (options.control_path != NULL)