upstream commit

Tweak config reparsing with host canonicalisation

Make the second pass through the config files always run when
hostname canonicalisation is enabled.

Add a "Match canonical" criteria that allows ssh_config Match
blocks to trigger only in the second config pass.

Add a -G option to ssh that causes it to parse its configuration
and dump the result to stdout, similar to "sshd -T"

Allow ssh_config Port options set in the second config parse
phase to be applied (they were being ignored).

bz#2267 bz#2286; ok markus

6 files changed, 504 insertions, 109 deletions

diff --git a/readconf.c b/readconf.c
index 7948ce1cd..869a1c4d8 100644
--- a/readconf.c
+++ b/readconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.c,v 1.220 2014/07/15 15:54:14 millert Exp $ */
+/* $OpenBSD: readconf.c,v 1.221 2014/10/08 22:20:25 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -41,6 +41,9 @@
 #ifdef HAVE_UTIL_H
 #include <util.h>
 #endif
+#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
+# include <vis.h>
+#endif
 
 #include "xmalloc.h"
 #include "ssh.h"
@@ -56,6 +59,7 @@
 #include "kex.h"
 #include "mac.h"
 #include "uidswap.h"
+#include "myproposal.h"
 
 /* Format of the configuration file:
 
@@ -135,7 +139,7 @@ typedef enum {
         oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression,
         oCompressionLevel, oTCPKeepAlive, oNumberOfPasswordPrompts,
         oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol, oMacs,
-        oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication,
+        oPubkeyAuthentication,
         oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias,
         oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication,
         oHostKeyAlgorithms, oBindAddress, oPKCS11Provider,
@@ -212,7 +216,7 @@ static struct {
         { "globalknownhostsfile", oGlobalKnownHostsFile },
         { "globalknownhostsfile2", oDeprecated },
         { "userknownhostsfile", oUserKnownHostsFile },
-        { "userknownhostsfile2", oDeprecated }, 
+        { "userknownhostsfile2", oDeprecated },
         { "connectionattempts", oConnectionAttempts },
         { "batchmode", oBatchMode },
         { "checkhostip", oCheckHostIP },
@@ -466,7 +470,7 @@ execute_in_shell(const char *cmd)
         if (!WIFEXITED(status)) {
                 error("command '%.100s' exited abnormally", cmd);
                 return -1;
-        } 
+        }
         debug3("command returned status %d", WEXITSTATUS(status));
         return WEXITSTATUS(status);
 }
@@ -476,11 +480,12 @@ execute_in_shell(const char *cmd)
  */
 static int
 match_cfg_line(Options *options, char **condition, struct passwd *pw,
-    const char *host_arg, const char *filename, int linenum)
+    const char *host_arg, const char *original_host, int post_canon,
+    const char *filename, int linenum)
 {
-        char *arg, *attrib, *cmd, *cp = *condition, *host;
+        char *arg, *oattrib, *attrib, *cmd, *cp = *condition, *host, *criteria;
         const char *ruser;
-        int r, port, result = 1, attributes = 0;
+        int r, port, this_result, result = 1, attributes = 0, negate;
         size_t len;
         char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
 
@@ -497,21 +502,38 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
         } else
                 host = xstrdup(host_arg);
 
-        debug3("checking match for '%s' host %s", cp, host);
-        while ((attrib = strdelim(&cp)) && *attrib != '\0') {
-                attributes++;
+        debug2("checking match for '%s' host %s originally %s",
+            cp, host, original_host);
+        while ((oattrib = attrib = strdelim(&cp)) && *attrib != '\0') {
+                criteria = NULL;
+                this_result = 1;
+                if ((negate = attrib[0] == '!'))
+                        attrib++;
+                /* criteria "all" and "canonical" have no argument */
                 if (strcasecmp(attrib, "all") == 0) {
-                        if (attributes != 1 ||
+                        if (attributes > 1 ||
                             ((arg = strdelim(&cp)) != NULL && *arg != '\0')) {
-                                error("'all' cannot be combined with other "
-                                    "Match attributes");
+                                error("%.200s line %d: '%s' cannot be combined "
+                                    "with other Match attributes",
+                                    filename, linenum, oattrib);
                                 result = -1;
                                 goto out;
                         }
-                        *condition = cp;
-                        result = 1;
+                        if (result)
+                                result = negate ? 0 : 1;
                         goto out;
                 }
+                attributes++;
+                if (strcasecmp(attrib, "canonical") == 0) {
+                        r = !!post_canon;  /* force bitmask member to boolean */
+                        if (r == (negate ? 1 : 0))
+                                this_result = result = 0;
+                        debug3("%.200s line %d: %smatched '%s'",
+                            filename, linenum,
+                            this_result ? "" : "not ", oattrib);
+                        continue;
+                }
+                /* All other criteria require an argument */
                 if ((arg = strdelim(&cp)) == NULL || *arg == '\0') {
                         error("Missing Match criteria for %s", attrib);
                         result = -1;
@@ -519,31 +541,25 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
                 }
                 len = strlen(arg);
                 if (strcasecmp(attrib, "host") == 0) {
-                        if (match_hostname(host, arg, len) != 1)
-                                result = 0;
-                        else
-                                debug("%.200s line %d: matched 'Host %.100s' ",
-                                    filename, linenum, host);
+                        criteria = xstrdup(host);
+                        r = match_hostname(host, arg, len) == 1;
+                        if (r == (negate ? 1 : 0))
+                                this_result = result = 0;
                 } else if (strcasecmp(attrib, "originalhost") == 0) {
-                        if (match_hostname(host_arg, arg, len) != 1)
-                                result = 0;
-                        else
-                                debug("%.200s line %d: matched "
-                                    "'OriginalHost %.100s' ",
-                                    filename, linenum, host_arg);
+                        criteria = xstrdup(original_host);
+                        r = match_hostname(original_host, arg, len) == 1;
+                        if (r == (negate ? 1 : 0))
+                                this_result = result = 0;
                 } else if (strcasecmp(attrib, "user") == 0) {
-                        if (match_pattern_list(ruser, arg, len, 0) != 1)
-                                result = 0;
-                        else
-                                debug("%.200s line %d: matched 'User %.100s' ",
-                                    filename, linenum, ruser);
+                        criteria = xstrdup(ruser);
+                        r = match_pattern_list(ruser, arg, len, 0) == 1;
+                        if (r == (negate ? 1 : 0))
+                                this_result = result = 0;
                 } else if (strcasecmp(attrib, "localuser") == 0) {
-                        if (match_pattern_list(pw->pw_name, arg, len, 0) != 1)
-                                result = 0;
-                        else
-                                debug("%.200s line %d: matched "
-                                    "'LocalUser %.100s' ",
-                                    filename, linenum, pw->pw_name);
+                        criteria = xstrdup(pw->pw_name);
+                        r = match_pattern_list(pw->pw_name, arg, len, 0) == 1;
+                        if (r == (negate ? 1 : 0))
+                                this_result = result = 0;
                 } else if (strcasecmp(attrib, "exec") == 0) {
                         if (gethostname(thishost, sizeof(thishost)) == -1)
                                 fatal("gethostname: %s", strerror(errno));
@@ -556,47 +572,49 @@ match_cfg_line(Options *options, char **condition, struct passwd *pw,
                             "d", pw->pw_dir,
                             "h", host,
                             "l", thishost,
-                            "n", host_arg,
+                            "n", original_host,
                             "p", portstr,
                             "r", ruser,
                             "u", pw->pw_name,
                             (char *)NULL);
                         if (result != 1) {
                                 /* skip execution if prior predicate failed */
-                                debug("%.200s line %d: skipped exec \"%.100s\"",
-                                    filename, linenum, cmd);
-                        } else {
-                                r = execute_in_shell(cmd);
-                                if (r == -1) {
-                                        fatal("%.200s line %d: match exec "
-                                            "'%.100s' error", filename,
-                                            linenum, cmd);
-                                } else if (r == 0) {
-                                        debug("%.200s line %d: matched "
-                                            "'exec \"%.100s\"'", filename,
-                                            linenum, cmd);
-                                } else {
-                                        debug("%.200s line %d: no match "
-                                            "'exec \"%.100s\"'", filename,
-                                            linenum, cmd);
-                                        result = 0;
-                                }
+                                debug3("%.200s line %d: skipped exec "
+                                    "\"%.100s\"", filename, linenum, cmd);
+                                free(cmd);
+                                continue;
+                        }
+                        r = execute_in_shell(cmd);
+                        if (r == -1) {
+                                fatal("%.200s line %d: match exec "
+                                    "'%.100s' error", filename,
+                                    linenum, cmd);
                         }
+                        criteria = xstrdup(cmd);
                         free(cmd);
+                        /* Force exit status to boolean */
+                        r = r == 0;
+                        if (r == (negate ? 1 : 0))
+                                this_result = result = 0;
                 } else {
                         error("Unsupported Match attribute %s", attrib);
                         result = -1;
                         goto out;
                 }
+                debug3("%.200s line %d: %smatched '%s \"%.100s\"' ",
+                    filename, linenum, this_result ? "": "not ",
+                    oattrib, criteria);
+                free(criteria);
         }
         if (attributes == 0) {
                 error("One or more attributes required for Match");
                 result = -1;
                 goto out;
         }
-        debug3("match %sfound", result ? "" : "not ");
-        *condition = cp;
  out:
+        if (result != -1)
+                debug2("match %sfound", result ? "" : "not ");
+        *condition = cp;
         free(host);
         return result;
 }
@@ -719,7 +737,8 @@ static const struct multistate multistate_canonicalizehostname[] = {
 #define WHITESPACE " \t\r\n"
 int
 process_config_line(Options *options, struct passwd *pw, const char *host,
-    char *line, const char *filename, int linenum, int *activep, int userconfig)
+    const char *original_host, char *line, const char *filename,
+    int linenum, int *activep, int flags)
 {
         char *s, **charptr, *endofnumber, *keyword, *arg, *arg2;
         char **cpptr, fwdarg[256];
@@ -775,7 +794,9 @@ parse_time:
                 if (!arg || *arg == '\0')
                         fatal("%s line %d: missing time value.",
                             filename, linenum);
-                if ((value = convtime(arg)) == -1)
+                if (strcmp(arg, "none") == 0)
+                        value = -1;
+                else if ((value = convtime(arg)) == -1)
                         fatal("%s line %d: invalid time value.",
                             filename, linenum);
                 if (*activep && *intptr == -1)
@@ -812,7 +833,7 @@ parse_time:
         case oForwardX11Trusted:
                 intptr = &options->forward_x11_trusted;
                 goto parse_flag;
-        
+
         case oForwardX11Timeout:
                 intptr = &options->forward_x11_timeout;
                 goto parse_time;
@@ -947,7 +968,8 @@ parse_time:
                         if (*intptr >= SSH_MAX_IDENTITY_FILES)
                                 fatal("%.200s line %d: Too many identity files specified (max %d).",
                                     filename, linenum, SSH_MAX_IDENTITY_FILES);
-                        add_identity_file(options, NULL, arg, userconfig);
+                        add_identity_file(options, NULL,
+                            arg, flags & SSHCONF_USERCONF);
                 }
                 break;
 
@@ -1195,8 +1217,8 @@ parse_int:
                 if (cmdline)
                         fatal("Host directive not supported as a command-line "
                             "option");
-                value = match_cfg_line(options, &s, pw, host,
-                    filename, linenum);
+                value = match_cfg_line(options, &s, pw, host, original_host,
+                    flags & SSHCONF_POSTCANON, filename, linenum);
                 if (value < 0)
                         fatal("%.200s line %d: Bad Match condition", filename,
                             linenum);
@@ -1444,7 +1466,7 @@ parse_int:
                 return 0;
 
         default:
-                fatal("process_config_line: Unimplemented opcode %d", opcode);
+                fatal("%s: Unimplemented opcode %d", __func__, opcode);
         }
 
         /* Check that there is no garbage at end of line. */
@@ -1464,7 +1486,7 @@ parse_int:
 
 int
 read_config_file(const char *filename, struct passwd *pw, const char *host,
-    Options *options, int flags)
+    const char *original_host, Options *options, int flags)
 {
         FILE *f;
         char line[1024];
@@ -1495,8 +1517,8 @@ read_config_file(const char *filename, struct passwd *pw, const char *host,
         while (fgets(line, sizeof(line), f)) {
                 /* Update line number counter. */
                 linenum++;
-                if (process_config_line(options, pw, host, line, filename,
-                    linenum, &active, flags & SSHCONF_USERCONF) != 0)
+                if (process_config_line(options, pw, host, original_host,
+                    line, filename, linenum, &active, flags) != 0)
                         bad_options++;
         }
         fclose(f);
@@ -2009,3 +2031,295 @@ parse_forward(struct Forward *fwd, const char *fwdspec, int dynamicfwd, int remo
         fwd->listen_path = NULL;
         return (0);
 }
+
+/* XXX the following is a near-vebatim copy from servconf.c; refactor */
+static const char *
+fmt_multistate_int(int val, const struct multistate *m)
+{
+        u_int i;
+
+        for (i = 0; m[i].key != NULL; i++) {
+                if (m[i].value == val)
+                        return m[i].key;
+        }
+        return "UNKNOWN";
+}
+
+static const char *
+fmt_intarg(OpCodes code, int val)
+{
+        if (val == -1)
+                return "unset";
+        switch (code) {
+        case oAddressFamily:
+                return fmt_multistate_int(val, multistate_addressfamily);
+        case oVerifyHostKeyDNS:
+        case oStrictHostKeyChecking:
+                return fmt_multistate_int(val, multistate_yesnoask);
+        case oControlMaster:
+                return fmt_multistate_int(val, multistate_controlmaster);
+        case oTunnel:
+                return fmt_multistate_int(val, multistate_tunnel);
+        case oRequestTTY:
+                return fmt_multistate_int(val, multistate_requesttty);
+        case oCanonicalizeHostname:
+                return fmt_multistate_int(val, multistate_canonicalizehostname);
+        case oProtocol:
+                switch (val) {
+                case SSH_PROTO_1:
+                        return "1";
+                case SSH_PROTO_2:
+                        return "2";
+                case (SSH_PROTO_1|SSH_PROTO_2):
+                        return "2,1";
+                default:
+                        return "UNKNOWN";
+                }
+        default:
+                switch (val) {
+                case 0:
+                        return "no";
+                case 1:
+                        return "yes";
+                default:
+                        return "UNKNOWN";
+                }
+        }
+}
+
+static const char *
+lookup_opcode_name(OpCodes code)
+{
+        u_int i;
+
+        for (i = 0; keywords[i].name != NULL; i++)
+                if (keywords[i].opcode == code)
+                        return(keywords[i].name);
+        return "UNKNOWN";
+}
+
+static void
+dump_cfg_int(OpCodes code, int val)
+{
+        printf("%s %d\n", lookup_opcode_name(code), val);
+}
+
+static void
+dump_cfg_fmtint(OpCodes code, int val)
+{
+        printf("%s %s\n", lookup_opcode_name(code), fmt_intarg(code, val));
+}
+
+static void
+dump_cfg_string(OpCodes code, const char *val)
+{
+        if (val == NULL)
+                return;
+        printf("%s %s\n", lookup_opcode_name(code), val);
+}
+
+static void
+dump_cfg_strarray(OpCodes code, u_int count, char **vals)
+{
+        u_int i;
+
+        for (i = 0; i < count; i++)
+                printf("%s %s\n", lookup_opcode_name(code), vals[i]);
+}
+
+static void
+dump_cfg_strarray_oneline(OpCodes code, u_int count, char **vals)
+{
+        u_int i;
+
+        printf("%s", lookup_opcode_name(code));
+        for (i = 0; i < count; i++)
+                printf(" %s",  vals[i]);
+        printf("\n");
+}
+
+static void
+dump_cfg_forwards(OpCodes code, u_int count, const struct Forward *fwds)
+{
+        const struct Forward *fwd;
+        u_int i;
+
+        /* oDynamicForward */
+        for (i = 0; i < count; i++) {
+                fwd = &fwds[i];
+                if (code == oDynamicForward &&
+                    strcmp(fwd->connect_host, "socks") != 0)
+                        continue;
+                if (code == oLocalForward &&
+                    strcmp(fwd->connect_host, "socks") == 0)
+                        continue;
+                printf("%s", lookup_opcode_name(code));
+                if (fwd->listen_port == PORT_STREAMLOCAL)
+                        printf(" %s", fwd->listen_path);
+                else if (fwd->listen_host == NULL)
+                        printf(" %d", fwd->listen_port);
+                else {
+                        printf(" [%s]:%d",
+                            fwd->listen_host, fwd->listen_port);
+                }
+                if (code != oDynamicForward) {
+                        if (fwd->connect_port == PORT_STREAMLOCAL)
+                                printf(" %s", fwd->connect_path);
+                        else if (fwd->connect_host == NULL)
+                                printf(" %d", fwd->connect_port);
+                        else {
+                                printf(" [%s]:%d",
+                                    fwd->connect_host, fwd->connect_port);
+                        }
+                }
+                printf("\n");
+        }
+}
+
+void
+dump_client_config(Options *o, const char *host)
+{
+        int i;
+        char vbuf[5];
+
+        /* Most interesting options first: user, host, port */
+        dump_cfg_string(oUser, o->user);
+        dump_cfg_string(oHostName, host);
+        dump_cfg_int(oPort, o->port);
+
+        /* Flag options */
+        dump_cfg_fmtint(oAddressFamily, o->address_family);
+        dump_cfg_fmtint(oBatchMode, o->batch_mode);
+        dump_cfg_fmtint(oCanonicalizeFallbackLocal, o->canonicalize_fallback_local);
+        dump_cfg_fmtint(oCanonicalizeHostname, o->canonicalize_hostname);
+        dump_cfg_fmtint(oChallengeResponseAuthentication, o->challenge_response_authentication);
+        dump_cfg_fmtint(oCheckHostIP, o->check_host_ip);
+        dump_cfg_fmtint(oCompression, o->compression);
+        dump_cfg_fmtint(oControlMaster, o->control_master);
+        dump_cfg_fmtint(oEnableSSHKeysign, o->enable_ssh_keysign);
+        dump_cfg_fmtint(oExitOnForwardFailure, o->exit_on_forward_failure);
+        dump_cfg_fmtint(oForwardAgent, o->forward_agent);
+        dump_cfg_fmtint(oForwardX11, o->forward_x11);
+        dump_cfg_fmtint(oForwardX11Trusted, o->forward_x11_trusted);
+        dump_cfg_fmtint(oGatewayPorts, o->fwd_opts.gateway_ports);
+#ifdef GSSAPI
+        dump_cfg_fmtint(oGssAuthentication, o->gss_authentication);
+        dump_cfg_fmtint(oGssDelegateCreds, o->gss_deleg_creds);
+#endif /* GSSAPI */
+        dump_cfg_fmtint(oHashKnownHosts, o->hash_known_hosts);
+        dump_cfg_fmtint(oHostbasedAuthentication, o->hostbased_authentication);
+        dump_cfg_fmtint(oIdentitiesOnly, o->identities_only);
+        dump_cfg_fmtint(oKbdInteractiveAuthentication, o->kbd_interactive_authentication);
+        dump_cfg_fmtint(oNoHostAuthenticationForLocalhost, o->no_host_authentication_for_localhost);
+        dump_cfg_fmtint(oPasswordAuthentication, o->password_authentication);
+        dump_cfg_fmtint(oPermitLocalCommand, o->permit_local_command);
+        dump_cfg_fmtint(oProtocol, o->protocol);
+        dump_cfg_fmtint(oProxyUseFdpass, o->proxy_use_fdpass);
+        dump_cfg_fmtint(oPubkeyAuthentication, o->pubkey_authentication);
+        dump_cfg_fmtint(oRequestTTY, o->request_tty);
+        dump_cfg_fmtint(oRhostsRSAAuthentication, o->rhosts_rsa_authentication);
+        dump_cfg_fmtint(oRSAAuthentication, o->rsa_authentication);
+        dump_cfg_fmtint(oStreamLocalBindUnlink, o->fwd_opts.streamlocal_bind_unlink);
+        dump_cfg_fmtint(oStrictHostKeyChecking, o->strict_host_key_checking);
+        dump_cfg_fmtint(oTCPKeepAlive, o->tcp_keep_alive);
+        dump_cfg_fmtint(oTunnel, o->tun_open);
+        dump_cfg_fmtint(oUsePrivilegedPort, o->use_privileged_port);
+        dump_cfg_fmtint(oVerifyHostKeyDNS, o->verify_host_key_dns);
+        dump_cfg_fmtint(oVisualHostKey, o->visual_host_key);
+
+        /* Integer options */
+        dump_cfg_int(oCanonicalizeMaxDots, o->canonicalize_max_dots);
+        dump_cfg_int(oCompressionLevel, o->compression_level);
+        dump_cfg_int(oConnectionAttempts, o->connection_attempts);
+        dump_cfg_int(oForwardX11Timeout, o->forward_x11_timeout);
+        dump_cfg_int(oNumberOfPasswordPrompts, o->number_of_password_prompts);
+        dump_cfg_int(oServerAliveCountMax, o->server_alive_count_max);
+        dump_cfg_int(oServerAliveInterval, o->server_alive_interval);
+
+        /* String options */
+        dump_cfg_string(oBindAddress, o->bind_address);
+        dump_cfg_string(oCiphers, o->ciphers ? o->ciphers : KEX_CLIENT_ENCRYPT);
+        dump_cfg_string(oControlPath, o->control_path);
+        dump_cfg_string(oHostKeyAlgorithms, o->hostkeyalgorithms ? o->hostkeyalgorithms : KEX_DEFAULT_PK_ALG);
+        dump_cfg_string(oHostKeyAlias, o->host_key_alias);
+        dump_cfg_string(oKbdInteractiveDevices, o->kbd_interactive_devices);
+        dump_cfg_string(oKexAlgorithms, o->kex_algorithms ? o->kex_algorithms : KEX_CLIENT_KEX);
+        dump_cfg_string(oLocalCommand, o->local_command);
+        dump_cfg_string(oLogLevel, log_level_name(o->log_level));
+        dump_cfg_string(oMacs, o->macs ? o->macs : KEX_CLIENT_MAC);
+        dump_cfg_string(oPKCS11Provider, o->pkcs11_provider);
+        dump_cfg_string(oPreferredAuthentications, o->preferred_authentications);
+        dump_cfg_string(oProxyCommand, o->proxy_command);
+        dump_cfg_string(oXAuthLocation, o->xauth_location);
+
+        dump_cfg_forwards(oDynamicForward, o->num_local_forwards, o->local_forwards);
+        dump_cfg_forwards(oLocalForward, o->num_local_forwards, o->local_forwards);
+        dump_cfg_forwards(oRemoteForward, o->num_remote_forwards, o->remote_forwards);
+
+        /* String array options */
+        dump_cfg_strarray(oIdentityFile, o->num_identity_files, o->identity_files);
+        dump_cfg_strarray_oneline(oCanonicalDomains, o->num_canonical_domains, o->canonical_domains);
+        dump_cfg_strarray_oneline(oGlobalKnownHostsFile, o->num_system_hostfiles, o->system_hostfiles);
+        dump_cfg_strarray_oneline(oUserKnownHostsFile, o->num_user_hostfiles, o->user_hostfiles);
+        dump_cfg_strarray(oSendEnv, o->num_send_env, o->send_env);
+
+        /* Special cases */
+
+        /* oConnectTimeout */
+        if (o->connection_timeout == -1)
+                printf("connecttimeout none\n");
+        else
+                dump_cfg_int(oConnectTimeout, o->connection_timeout);
+
+        /* oTunnelDevice */
+        printf("tunneldevice");
+        if (o->tun_local == SSH_TUNID_ANY)
+                printf(" any");
+        else
+                printf(" %d", o->tun_local);
+        if (o->tun_remote == SSH_TUNID_ANY)
+                printf(":any");
+        else
+                printf(":%d", o->tun_remote);
+        printf("\n");
+
+        /* oCanonicalizePermittedCNAMEs */
+        if ( o->num_permitted_cnames > 0) {
+                printf("canonicalizePermittedcnames");
+                for (i = 0; i < o->num_permitted_cnames; i++) {
+                        printf(" %s:%s", o->permitted_cnames[i].source_list,
+                            o->permitted_cnames[i].target_list);
+                }
+                printf("\n");
+        }
+
+        /* oCipher */
+        if (o->cipher != SSH_CIPHER_NOT_SET)
+                printf("Cipher %s\n", cipher_name(o->cipher));
+
+        /* oControlPersist */
+        if (o->control_persist == 0 || o->control_persist_timeout == 0)
+                dump_cfg_fmtint(oControlPersist, o->control_persist);
+        else
+                dump_cfg_int(oControlPersist, o->control_persist_timeout);
+
+        /* oEscapeChar */
+        if (o->escape_char == SSH_ESCAPECHAR_NONE)
+                printf("escapechar none\n");
+        else {
+                vis(vbuf, o->escape_char, VIS_WHITE, 0);
+                printf("escapechar %s\n", vbuf);
+        }
+
+        /* oIPQoS */
+        printf("ipqos %s ", iptos2str(o->ip_qos_interactive));
+        printf("%s\n", iptos2str(o->ip_qos_bulk));
+
+        /* oRekeyLimit */
+        printf("rekeylimit %lld %d\n",
+            (long long)o->rekey_limit, o->rekey_interval);
+
+        /* oStreamLocalBindMask */
+        printf("streamlocalbindmask 0%o\n",
+            o->fwd_opts.streamlocal_bind_mask);
+}
diff --git a/readconf.h b/readconf.h
index 0b9cb777a..7b58d01f3 100644
--- a/readconf.h
+++ b/readconf.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.h,v 1.102 2014/07/15 15:54:14 millert Exp $ */
+/* $OpenBSD: readconf.h,v 1.103 2014/10/08 22:20:25 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -164,17 +164,19 @@ typedef struct {
 
 #define SSHCONF_CHECKPERM       1  /* check permissions on config file */
 #define SSHCONF_USERCONF        2  /* user provided config file not system */
+#define SSHCONF_POSTCANON       4  /* After hostname canonicalisation */
 
 void     initialize_options(Options *);
 void     fill_default_options(Options *);
 void     fill_default_options_for_canonicalization(Options *);
-int      process_config_line(Options *, struct passwd *, const char *, char *,
-    const char *, int, int *, int);
+int      process_config_line(Options *, struct passwd *, const char *,
+    const char *, char *, const char *, int, int *, int);
 int      read_config_file(const char *, struct passwd *, const char *,
-    Options *, int);
+    const char *, Options *, int);
 int      parse_forward(struct Forward *, const char *, int, int);
 int      default_ssh_port(void);
 int      option_clear_or_none(const char *);
+void     dump_client_config(Options *o, const char *host);
 
 void     add_local_forward(Options *, const struct Forward *);
 void     add_remote_forward(Options *, const struct Forward *);
diff --git a/ssh-keysign.c b/ssh-keysign.c
index d95bb7d9d..6b73319e0 100644
--- a/ssh-keysign.c
+++ b/ssh-keysign.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keysign.c,v 1.42 2014/04/29 18:01:49 markus Exp $ */
+/* $OpenBSD: ssh-keysign.c,v 1.43 2014/10/08 22:20:25 djm Exp $ */
 /*
  * Copyright (c) 2002 Markus Friedl.  All rights reserved.
  *
@@ -187,7 +187,7 @@ main(int argc, char **argv)
 
         /* verify that ssh-keysign is enabled by the admin */
         initialize_options(&options);
-        (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, "", &options, 0);
+        (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, "", "", &options, 0);
         fill_default_options(&options);
         if (options.enable_ssh_keysign != 1)
                 fatal("ssh-keysign not enabled in %s",
diff --git a/ssh.1 b/ssh.1
index 1c889b6c4..34fe635e4 100644
--- a/ssh.1
+++ b/ssh.1
@@ -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.1,v 1.349 2014/08/30 15:33:50 sobrado Exp $
-.Dd $Mdocdate: August 30 2014 $
+.\" $OpenBSD: ssh.1,v 1.350 2014/10/08 22:20:25 djm Exp $
+.Dd $Mdocdate: October 8 2014 $
 .Dt SSH 1
 .Os
 .Sh NAME
@@ -43,7 +43,7 @@
 .Sh SYNOPSIS
 .Nm ssh
 .Bk -words
-.Op Fl 1246AaCfgKkMNnqsTtVvXxYy
+.Op Fl 1246AaCfgGKkMNnqsTtVvXxYy
 .Op Fl b Ar bind_address
 .Op Fl c Ar cipher_spec
 .Op Fl D Oo Ar bind_address : Oc Ns Ar port
@@ -251,6 +251,14 @@ then a client started with
 .Fl f
 will wait for all remote port forwards to be successfully established
 before placing itself in the background.
+.It Fl G
+Causes
+.Nm
+to print its configuration after evaluating
+.Cm Host
+and
+.Cm Match
+blocks and exit.
 .It Fl g
 Allows remote hosts to connect to local forwarded ports.
 If used on a multiplexed connection, then this option must be specified
diff --git a/ssh.c b/ssh.c
index 26e9681b7..97f6e821d 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.407 2014/07/17 07:22:19 djm Exp $ */
+/* $OpenBSD: ssh.c,v 1.408 2014/10/08 22:20:25 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -384,27 +384,49 @@ resolve_canonicalize(char **hostp, int port)
  * file if the user specifies a config file on the command line.
  */
 static void
-process_config_files(struct passwd *pw)
+process_config_files(const char *host_arg, struct passwd *pw, int post_canon)
 {
         char buf[MAXPATHLEN];
         int r;
 
         if (config != NULL) {
                 if (strcasecmp(config, "none") != 0 &&
-                    !read_config_file(config, pw, host, &options,
-                    SSHCONF_USERCONF))
+                    !read_config_file(config, pw, host, host_arg, &options,
+                    SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0)))
                         fatal("Can't open user config file %.100s: "
                             "%.100s", config, strerror(errno));
         } else {
                 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
                     _PATH_SSH_USER_CONFFILE);
                 if (r > 0 && (size_t)r < sizeof(buf))
-                        (void)read_config_file(buf, pw, host, &options,
-                             SSHCONF_CHECKPERM|SSHCONF_USERCONF);
+                        (void)read_config_file(buf, pw, host, host_arg,
+                            &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
+                            (post_canon ? SSHCONF_POSTCANON : 0));
 
                 /* Read systemwide configuration file after user config. */
-                (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, host,
-                    &options, 0);
+                (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
+                    host, host_arg, &options,
+                    post_canon ? SSHCONF_POSTCANON : 0);
+        }
+}
+
+/* Rewrite the port number in an addrinfo list of addresses */
+static void
+set_addrinfo_port(struct addrinfo *addrs, int port)
+{
+        struct addrinfo *addr;
+
+        for (addr = addrs; addr != NULL; addr = addr->ai_next) {
+                switch (addr->ai_family) {
+                case AF_INET:
+                        ((struct sockaddr_in *)addr->ai_addr)->
+                            sin_port = htons(port);
+                        break;
+                case AF_INET6:
+                        ((struct sockaddr_in6 *)addr->ai_addr)->
+                            sin6_port = htons(port);
+                        break;
+                }
         }
 }
 
@@ -414,7 +436,7 @@ process_config_files(struct passwd *pw)
 int
 main(int ac, char **av)
 {
-        int i, r, opt, exit_status, use_syslog;
+        int i, r, opt, exit_status, use_syslog, config_test = 0;
         char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg, *logfile;
         char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
         char cname[NI_MAXHOST];
@@ -507,7 +529,7 @@ main(int ac, char **av)
 
  again:
         while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
-            "ACD:E:F:I:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
+            "ACD:E:F:GI:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
                 switch (opt) {
                 case '1':
                         options.protocol = SSH_PROTO_1;
@@ -540,6 +562,9 @@ main(int ac, char **av)
                 case 'E':
                         logfile = xstrdup(optarg);
                         break;
+                case 'G':
+                        config_test = 1;
+                        break;
                 case 'Y':
                         options.forward_x11 = 1;
                         options.forward_x11_trusted = 1;
@@ -788,9 +813,9 @@ main(int ac, char **av)
                         break;
                 case 'o':
                         line = xstrdup(optarg);
-                        if (process_config_line(&options, pw, host ? host : "",
-                            line, "command-line", 0, NULL, SSHCONF_USERCONF)
-                            != 0)
+                        if (process_config_line(&options, pw,
+                            host ? host : "", host ? host : "", line,
+                            "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
                                 exit(255);
                         free(line);
                         break;
@@ -899,7 +924,7 @@ main(int ac, char **av)
                 );
 
         /* Parse the configuration files */
-        process_config_files(pw);
+        process_config_files(host_arg, pw, 0);
 
         /* Hostname canonicalisation needs a few options filled. */
         fill_default_options_for_canonicalization(&options);
@@ -911,6 +936,8 @@ main(int ac, char **av)
                     "h", host, (char *)NULL);
                 free(host);
                 host = cp;
+                free(options.hostname);
+                options.hostname = xstrdup(host);
         }
 
         /* If canonicalization requested then try to apply it */
@@ -945,12 +972,22 @@ main(int ac, char **av)
         }
 
         /*
-         * If the target hostname has changed as a result of canonicalisation
-         * then re-parse the configuration files as new stanzas may match.
+         * If canonicalisation is enabled then re-parse the configuration
+         * files as new stanzas may match.
          */
-        if (strcasecmp(host_arg, host) != 0) {
-                debug("Hostname has changed; re-reading configuration");
-                process_config_files(pw);
+        if (options.canonicalize_hostname != 0) {
+                debug("Re-reading configuration after hostname "
+                    "canonicalisation");
+                free(options.hostname);
+                options.hostname = xstrdup(host);
+                process_config_files(host_arg, pw, 1);
+                /*
+                 * Address resolution happens early with canonicalisation
+                 * enabled and the port number may have changed since, so
+                 * reset it in address list
+                 */
+                if (addrs != NULL && options.port > 0)
+                        set_addrinfo_port(addrs, options.port);
         }
 
         /* Fill configuration defaults. */
@@ -1052,6 +1089,11 @@ main(int ac, char **av)
         }
         free(conn_hash_hex);
 
+        if (config_test) {
+                dump_client_config(&options, host);
+                exit(0);
+        }
+
         if (muxclient_command != 0 && options.control_path == NULL)
                 fatal("No ControlPath specified for \"-O\" command");
         if (options.control_path != NULL)
diff --git a/ssh_config.5 b/ssh_config.5
index 4396aa907..b702e323f 100644
--- 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 1.192 2014/08/30 15:33:50 sobrado Exp $
-.Dd $Mdocdate: August 30 2014 $
+.\" $OpenBSD: ssh_config.5,v 1.193 2014/10/08 22:20:25 djm Exp $
+.Dd $Mdocdate: October 8 2014 $
 .Dt SSH_CONFIG 5
 .Os
 .Sh NAME
@@ -65,7 +65,10 @@ The configuration files contain sections separated by
 .Dq Host
 specifications, and that section is only applied for hosts that
 match one of the patterns given in the specification.
-The matched host name is the one given on the command line.
+The matched host name is usually the one given on the command line
+(see the
+.Cm CanonicalizeHostname
+option for exceptions.)
 .Pp
 Since the first obtained value for each parameter is used, more
 host-specific declarations should be given near the beginning of the
@@ -109,10 +112,12 @@ A single
 .Ql *
 as a pattern can be used to provide global
 defaults for all hosts.
-The host is the
+The host is usually the
 .Ar hostname
-argument given on the command line (i.e. the name is not converted to
-a canonicalized host name before matching).
+argument given on the command line
+(see the
+.Cm CanonicalizeHostname
+option for exceptions.)
 .Pp
 A pattern entry may be negated by prefixing it with an exclamation mark
 .Pq Sq !\& .
@@ -134,19 +139,40 @@ or
 keyword) to be used only when the conditions following the
 .Cm Match
 keyword are satisfied.
-Match conditions are specified using one or more keyword/criteria pairs
+Match conditions are specified using one or more critera
 or the single token
 .Cm all
-which matches all criteria.
-The available keywords are:
+which always matches.
+The available criteria keywords are:
+.Cm canonical ,
 .Cm exec ,
 .Cm host ,
 .Cm originalhost ,
 .Cm user ,
 and
 .Cm localuser .
+The
+.Cm all
+criteria must appear alone or immediately after
+.Cm canonical.
+Other criteria may be combined arbitrarily.
+All criteria but
+.Cm all
+and
+.Cm canonical
+require an argument.
+Criteria may be negated by prepending an exclamation mark
+.Pq Sq !\& .
 .Pp
 The
+.Cm canonical
+keywork matches only when the configuration file is being re-parsed
+after hostname canonicalization (see the
+.Cm CanonicalizeHostname
+option.)
+This may be useful to specify conditions that work with canonical host
+names only.
+The
 .Cm exec
 keyword executes the specified command under the user's shell.
 If the command returns a zero exit status then the condition is considered true.
@@ -179,7 +205,9 @@ The criteria for the
 keyword are matched against the target hostname, after any substitution
 by the
 .Cm Hostname
-option.
+or
+.Cm CanonicalizeHostname
+options.
 The
 .Cm originalhost
 keyword matches against the hostname as it was specified on the command-line.
@@ -264,10 +292,11 @@ is set to
 .Dq always ,
 then canonicalization is applied to proxied connections too.
 .Pp
-If this option is enabled and canonicalisation results in the target hostname
-changing, then the configuration files are processed again using the new
-target name to pick up any new configuration in matching
+If this option is enabled, then the configuration files are processed
+again using the new target name to pick up any new configuration in matching
 .Cm Host
+and
+.Cm Match
 stanzas.
 .It Cm CanonicalizeMaxDots
 Specifies the maximum number of dot characters in a hostname before