upstream: Make with config keywords support which

percent_expansions more consistent.  - %C is moved into its own function and
added to Match Exec.  - move the common (global) options into a macro.  This
is ugly but it's    the least-ugly way I could come up with.  - move
IdentityAgent and ForwardAgent percent expansion to before the    config dump
to make it regression-testable.  - document all of the above

ok jmc@ for man page bits, "makes things less terrible" djm@ for the rest.

OpenBSD-Commit-ID: 4b65664bd6d8ae2a9afaf1a2438ddd1b614b1d75

diff --git a/readconf.c b/readconf.c
index f3cac6b3a89d23b1261812382bb0949f1c5a21e5..1a3b2db290fda6f0fd6deb4bd3c54f12828d8a62 100644 (file)
--- a/readconf.c
+++ b/readconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.c,v 1.326 2020/02/06 22:46:31 djm Exp $ */
+/* $OpenBSD: readconf.c,v 1.327 2020/04/03 02:27:12 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -324,6 +324,24 @@ kex_default_pk_alg(void)
        return kex_default_pk_alg_filtered;
 }
 
+char *
+ssh_connection_hash(const char *thishost, const char *host, const char *portstr,
+    const char *user)
+{
+       struct ssh_digest_ctx *md;
+       u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
+
+       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, user, strlen(user)) < 0 ||
+           ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0)
+               fatal("%s: mux digest failed", __func__);
+       ssh_digest_free(md);
+       return tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1));
+}
+
 /*
  * Adds a local TCP/IP port forward to options.  Never returns if there is an
  * error.
@@ -646,6 +664,8 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
                        if (r == (negate ? 1 : 0))
                                this_result = result = 0;
                } else if (strcasecmp(attrib, "exec") == 0) {
+                       char *conn_hash_hex;
+
                        if (gethostname(thishost, sizeof(thishost)) == -1)
                                fatal("gethostname: %s", strerror(errno));
                        strlcpy(shorthost, thishost, sizeof(shorthost));
@@ -653,8 +673,11 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
                        snprintf(portstr, sizeof(portstr), "%d", port);
                        snprintf(uidstr, sizeof(uidstr), "%llu",
                            (unsigned long long)pw->pw_uid);
+                       conn_hash_hex = ssh_connection_hash(thishost, host,
+                          portstr, pw->pw_name);
 
                        cmd = percent_expand(arg,
+                           "C", conn_hash_hex,
                            "L", shorthost,
                            "d", pw->pw_dir,
                            "h", host,
@@ -665,6 +688,7 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
                            "u", pw->pw_name,
                            "i", uidstr,
                            (char *)NULL);
+                       free(conn_hash_hex);
                        if (result != 1) {
                                /* skip execution if prior predicate failed */
                                debug3("%.200s line %d: skipped exec "

diff --git a/readconf.h b/readconf.h
index feedb3d202c3dd1c4fbc76f824d0f7d9fb7fd6af..e143a1082aecba1578674b6d9743420abc189314 100644 (file)
--- a/readconf.h
+++ b/readconf.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.h,v 1.132 2020/01/23 02:46:49 dtucker Exp $ */
+/* $OpenBSD: readconf.h,v 1.133 2020/04/03 02:27:12 dtucker Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -200,6 +200,8 @@ typedef struct {
 #define SSH_STRICT_HOSTKEY_ASK 3
 
 const char *kex_default_pk_alg(void);
+char   *ssh_connection_hash(const char *thishost, const char *host,
+    const char *portstr, const char *user);
 void     initialize_options(Options *);
 void     fill_default_options(Options *);
 void    fill_default_options_for_canonicalization(Options *);

diff --git a/ssh.c b/ssh.c
index 9713b61e121235106c7264b469e1cba45faedfee..470d9b7e6bbf763a2197df51cd1e2b9484e67005 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.521 2020/03/06 18:20:02 markus Exp $ */
+/* $OpenBSD: ssh.c,v 1.522 2020/04/03 02:27:12 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -86,7 +86,6 @@
 #include "canohost.h"
 #include "compat.h"
 #include "cipher.h"
-#include "digest.h"
 #include "packet.h"
 #include "sshbuf.h"
 #include "channels.h"
@@ -177,6 +176,13 @@ char *forward_agent_sock_path = NULL;
 /* Various strings used to to percent_expand() arguments */
 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
 static char uidstr[32], *host_arg, *conn_hash_hex;
+#define DEFAULT_CLIENT_PERCENT_EXPAND_ARGS \
+    "C", conn_hash_hex, \
+    "L", shorthost, \
+    "i", uidstr, \
+    "l", thishost, \
+    "n", host_arg, \
+    "p", portstr
 
 /* socket address the host resolves to */
 struct sockaddr_storage hostaddr;
@@ -601,8 +607,6 @@ main(int ac, char **av)
        extern char *optarg;
        struct Forward fwd;
        struct addrinfo *addrs = NULL;
-       struct ssh_digest_ctx *md;
-       u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
        size_t n, len;
 
        /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
@@ -1330,15 +1334,8 @@ main(int ac, char **av)
        snprintf(uidstr, sizeof(uidstr), "%llu",
            (unsigned long long)pw->pw_uid);
 
-       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));
+       conn_hash_hex = ssh_connection_hash(thishost, host, portstr,
+           options.user);
 
        /*
         * Expand tokens in arguments. NB. LocalCommand is expanded later,
@@ -1349,14 +1346,9 @@ main(int ac, char **av)
                debug3("expanding RemoteCommand: %s", options.remote_command);
                cp = options.remote_command;
                options.remote_command = percent_expand(cp,
-                   "C", conn_hash_hex,
-                   "L", shorthost,
+                   DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
                    "d", pw->pw_dir,
                    "h", host,
-                   "i", uidstr,
-                   "l", thishost,
-                   "n", host_arg,
-                   "p", portstr,
                    "r", options.user,
                    "u", pw->pw_name,
                    (char *)NULL);
@@ -1371,20 +1363,44 @@ main(int ac, char **av)
                cp = tilde_expand_filename(options.control_path, getuid());
                free(options.control_path);
                options.control_path = percent_expand(cp,
-                   "C", conn_hash_hex,
-                   "L", shorthost,
+                   DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
+                   "d", pw->pw_dir,
                    "h", host,
-                   "i", uidstr,
-                   "l", thishost,
-                   "n", host_arg,
-                   "p", portstr,
                    "r", options.user,
                    "u", pw->pw_name,
-                   "i", uidstr,
                    (char *)NULL);
                free(cp);
        }
 
+       if (options.identity_agent != NULL) {
+               p = tilde_expand_filename(options.identity_agent, getuid());
+               cp = percent_expand(p,
+                   DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
+                   "d", pw->pw_dir,
+                   "h", host,
+                   "r", options.user,
+                   "u", pw->pw_name,
+                   (char *)NULL);
+               free(p);
+               free(options.identity_agent);
+               options.identity_agent = cp;
+       }
+
+       if (options.forward_agent_sock_path != NULL) {
+               p = tilde_expand_filename(options.forward_agent_sock_path,
+                   getuid());
+               cp = percent_expand(p,
+                   DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
+                   "d", pw->pw_dir,
+                   "h", host,
+                   "r", options.user,
+                   "u", pw->pw_name,
+                   (char *)NULL);
+               free(p);
+               free(options.forward_agent_sock_path);
+               options.forward_agent_sock_path = cp;
+       }
+
        if (config_test) {
                dump_client_config(&options, host);
                exit(0);
@@ -1509,23 +1525,7 @@ main(int ac, char **av)
                if (strcmp(options.identity_agent, "none") == 0) {
                        unsetenv(SSH_AUTHSOCKET_ENV_NAME);
                } else {
-                       p = tilde_expand_filename(options.identity_agent,
-                           getuid());
-                       cp = percent_expand(p,
-                           "d", pw->pw_dir,
-                           "h", host,
-                           "i", uidstr,
-                           "l", thishost,
-                           "r", options.user,
-                           "u", pw->pw_name,
-                           (char *)NULL);
-                       free(p);
-                       /*
-                        * If identity_agent represents an environment variable
-                        * then recheck that it is valid (since processing with
-                        * percent_expand() may have changed it) and substitute
-                        * its value.
-                        */
+                       cp = options.identity_agent;
                        if (cp[0] == '$') {
                                if (!valid_env_name(cp + 1)) {
                                        fatal("Invalid IdentityAgent "
@@ -1539,22 +1539,10 @@ main(int ac, char **av)
                                /* identity_agent specifies a path directly */
                                setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
                        }
-                       free(cp);
                }
        }
 
-       if (options.forward_agent && (options.forward_agent_sock_path != NULL)) {
-               p = tilde_expand_filename(options.forward_agent_sock_path, getuid());
-               cp = percent_expand(p,
-                   "d", pw->pw_dir,
-                   "h", host,
-                   "i", uidstr,
-                   "l", thishost,
-                   "r", options.user,
-                   "u", pw->pw_name,
-                   (char *)NULL);
-               free(p);
-
+       if (options.forward_agent && options.forward_agent_sock_path != NULL) {
                if (cp[0] == '$') {
                        if (!valid_env_name(cp + 1)) {
                                fatal("Invalid ForwardAgent environment variable name %s", cp);
@@ -1979,14 +1967,9 @@ ssh_session2(struct ssh *ssh, struct passwd *pw)
                debug3("expanding LocalCommand: %s", options.local_command);
                cp = options.local_command;
                options.local_command = percent_expand(cp,
-                   "C", conn_hash_hex,
-                   "L", shorthost,
+                   DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
                    "d", pw->pw_dir,
                    "h", host,
-                   "i", uidstr,
-                   "l", thishost,
-                   "n", host_arg,
-                   "p", portstr,
                    "r", options.user,
                    "u", pw->pw_name,
                    "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname,
@@ -2143,9 +2126,13 @@ load_public_identity_files(struct passwd *pw)
                        continue;
                }
                cp = tilde_expand_filename(options.identity_files[i], getuid());
-               filename = percent_expand(cp, "d", pw->pw_dir,
-                   "u", pw->pw_name, "l", thishost, "h", host,
-                   "r", options.user, (char *)NULL);
+               filename = percent_expand(cp,
+                   DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
+                   "d", pw->pw_dir,
+                   "h", host,
+                   "r", options.user,
+                   "u", pw->pw_name,
+                   (char *)NULL);
                free(cp);
                check_load(sshkey_load_public(filename, &public, NULL),
                    filename, "pubkey");
@@ -2195,10 +2182,9 @@ load_public_identity_files(struct passwd *pw)
                cp = tilde_expand_filename(options.certificate_files[i],
                    getuid());
                filename = percent_expand(cp,
+                   DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
                    "d", pw->pw_dir,
                    "h", host,
-                   "i", uidstr,
-                   "l", thishost,
                    "r", options.user,
                    "u", pw->pw_name,
                    (char *)NULL);

diff --git a/ssh_config.5 b/ssh_config.5
index 06a32d3142a6427cd71adfda0327d0e5b95d02c2..9d89c13aa5cb4b5c701d4b1097c9e5ce94860ae9 100644 (file)
--- a/ssh_config.5
+++ b/ssh_config.5
@@ -33,8 +33,8 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh_config.5,v 1.322 2020/02/07 03:54:44 dtucker Exp $
-.Dd $Mdocdate: February 7 2020 $
+.\" $OpenBSD: ssh_config.5,v 1.323 2020/04/03 02:27:12 dtucker Exp $
+.Dd $Mdocdate: April 3 2020 $
 .Dt SSH_CONFIG 5
 .Os
 .Sh NAME
@@ -1845,31 +1845,23 @@ otherwise.
 The local username.
 .El
 .Pp
-.Cm Match exec
-accepts the tokens %%, %h, %i, %L, %l, %n, %p, %r, and %u.
-.Pp
-.Cm CertificateFile
-accepts the tokens %%, %d, %h, %i, %l, %r, and %u.
-.Pp
-.Cm ControlPath
-accepts the tokens %%, %C, %h, %i, %L, %l, %n, %p, %r, and %u.
+.Cm Match exec ,
+.Cm CertificateFile ,
+.Cm ControlPath ,
+.Cm IdentityAgent ,
+.Cm IdentityFile ,
+and
+.Cm RemoteCommand
+accept the tokens %%, %C, %d, %h, %i, %L, %l, %n, %p, %r, and %u.
 .Pp
 .Cm Hostname
 accepts the tokens %% and %h.
 .Pp
-.Cm IdentityAgent
-and
-.Cm IdentityFile
-accept the tokens %%, %d, %h, %i, %l, %r, and %u.
-.Pp
 .Cm LocalCommand
-accepts the tokens %%, %C, %d, %h, %i, %l, %n, %p, %r, %T, and %u.
+accepts all tokens.
 .Pp
 .Cm ProxyCommand
 accepts the tokens %%, %h, %n, %p, and %r.
-.Pp
-.Cm RemoteCommand
-accepts the tokens %%, %C, %d, %h, %i, %l, %n, %p, %r, and %u.
 .Sh FILES
 .Bl -tag -width Ds
 .It Pa ~/.ssh/config