/src/openssh/readconf.c

Source
/* $OpenBSD: readconf.c,v 1.419 2026/10/05 06:03:40 dtucker Exp $ */
/*
 * Author: Tatu Ylonen <ylo@cs.hut.fi>
 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
 *                    All rights reserved
 * Functions for reading the configuration files.
 *
 * As far as I am concerned, the code I have written for this software
 * can be used freely for any purpose.  Any derived versions of this
 * software must be clearly marked as such, and if the derived work is
 * incompatible with the protocol description in the RFC file, it must be
 * called by a name other than "ssh" or "Secure Shell".
 */

#include "includes.h"

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <sys/un.h>

#include <net/if.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <arpa/inet.h>

#include <ctype.h>
#include <errno.h>
#include <glob.h>
#include <ifaddrs.h>
#include <limits.h>
#include <netdb.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <util.h>
#if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) && !defined(BROKEN_STRNVIS)
# include <vis.h>
#endif

#include "xmalloc.h"
#include "ssh.h"
#include "cipher.h"
#include "pathnames.h"
#include "log.h"
#include "sshkey.h"
#include "misc.h"
#include "readconf.h"
#include "match.h"
#include "kex.h"
#include "mac.h"
#include "myproposal.h"
#include "digest.h"
#include "version.h"

/* Format of the configuration file:

   # Configuration data is parsed as follows:
   #  1. command line options
   #  2. user-specific file
   #  3. system-wide file
   # Any configuration value is only changed the first time it is set.
   # Thus, host-specific definitions should be at the beginning of the
   # configuration file, and defaults at the end.

   # Host-specific declarations.  These may override anything above.  A single
   # host may match multiple declarations; these are processed in the order
   # that they are given in.

   Host *.ngs.fi ngs.fi
     User foo

   Host fake.com
     Hostname another.host.name.real.org
     User blaah
     Port 34289
     ForwardX11 no
     ForwardAgent no

   Host books.com
     RemoteForward 9999 shadows.cs.hut.fi:9999
     Ciphers 3des-cbc

   Host fascist.blob.com
     Port 23123
     User tylonen
     PasswordAuthentication no

   Host puukko.hut.fi
     User t35124p
     ProxyCommand ssh-proxy %h %p

   Host *.fr
     PublicKeyAuthentication no

   Host *.su
     Ciphers aes128-ctr
     PasswordAuthentication no

   Host vpn.fake.com
     Tunnel yes
     TunnelDevice 3

   # Defaults for various options
   Host *
     ForwardAgent no
     ForwardX11 no
     PasswordAuthentication yes
     StrictHostKeyChecking yes
     TcpKeepAlive no
     IdentityFile ~/.ssh/identity
     Port 22
     EscapeChar ~

*/

static int read_config_file_depth(const char *filename, struct passwd *pw,
    const char *host, const char *original_host, const char *remote_command,
    Options *options, int flags, int *activep, int *want_final_pass, int depth);
static int process_config_line_depth(Options *options, struct passwd *pw,
    const char *host, const char *original_host, const char *remote_command,
    char *line, const char *filename, int linenum, int *activep, int flags,
    int *want_final_pass, int depth);

/* Keyword tokens. */

typedef enum {
  oBadOption,
  oHost, oMatch, oInclude, oTag,
  oForwardAgent, oForwardX11, oForwardX11Trusted, oForwardX11Timeout,
  oGatewayPorts, oExitOnForwardFailure,
  oPasswordAuthentication,
  oXAuthLocation,
  oIdentityFile, oHostname, oPort, oRemoteForward, oLocalForward,
  oPermitRemoteOpen,
  oCertificateFile, oAddKeysToAgent, oIdentityAgent,
  oUser, oEscapeChar, oProxyCommand,
  oGlobalKnownHostsFile, oUserKnownHostsFile, oConnectionAttempts,
  oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression,
  oTCPKeepAlive, oNumberOfPasswordPrompts,
  oLogFacility, oLogLevel, oLogVerbose, oCiphers, oMacs,
  oPubkeyAuthentication,
  oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias,
  oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication,
  oHostKeyAlgorithms, oBindAddress, oBindInterface, oPKCS11Provider,
  oClearAllForwardings, oNoHostAuthenticationForLocalhost,
  oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
  oAddressFamily, oGssAuthentication, oGssDelegateCreds,
  oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
  oSendEnv, oSetEnv, oControlPath, oControlMaster, oControlPersist,
  oHashKnownHosts,
  oTunnel, oTunnelDevice,
  oLocalCommand, oPermitLocalCommand, oRemoteCommand,
  oVisualHostKey,
  oKexAlgorithms, oIPQoS, oRequestTTY, oSessionType, oStdinNull,
  oForkAfterAuthentication, oIgnoreUnknown, oProxyUseFdpass,
  oCanonicalDomains, oCanonicalizeHostname, oCanonicalizeMaxDots,
  oCanonicalizeFallbackLocal, oCanonicalizePermittedCNAMEs,
  oStreamLocalBindMask, oStreamLocalBindUnlink, oRevokedHostKeys,
  oFingerprintHash, oUpdateHostkeys, oHostbasedAcceptedAlgorithms,
  oPubkeyAcceptedAlgorithms, oCASignatureAlgorithms, oProxyJump,
  oSecurityKeyProvider, oKnownHostsCommand, oRequiredRSASize,
  oEnableEscapeCommandline, oObscureKeystrokeTiming, oChannelTimeout,
  oVersionAddendum, oRefuseConnection, oWarnWeakCrypto,
  oIgnore, oIgnoredUnknownOption, oDeprecated, oUnsupported
} OpCodes;

/* Textual representations of the tokens. */

static struct {
  const char *name;
  OpCodes opcode;
} keywords[] = {
  /* Deprecated options */
  { "protocol", oIgnore }, /* NB. silently ignored */
  { "cipher", oDeprecated },
  { "fallbacktorsh", oDeprecated },
  { "globalknownhostsfile2", oDeprecated },
  { "rhostsauthentication", oDeprecated },
  { "userknownhostsfile2", oDeprecated },
  { "useroaming", oDeprecated },
  { "usersh", oDeprecated },
  { "useprivilegedport", oDeprecated },

  /* Unsupported options */
  { "afstokenpassing", oUnsupported },
  { "kerberosauthentication", oUnsupported },
  { "kerberostgtpassing", oUnsupported },
  { "rsaauthentication", oUnsupported },
  { "rhostsrsaauthentication", oUnsupported },
  { "compressionlevel", oUnsupported },

  /* Sometimes-unsupported options */
#if defined(GSSAPI)
  { "gssapiauthentication", oGssAuthentication },
  { "gssapidelegatecredentials", oGssDelegateCreds },
# else
  { "gssapiauthentication", oUnsupported },
  { "gssapidelegatecredentials", oUnsupported },
#endif
#ifdef ENABLE_PKCS11
  { "pkcs11provider", oPKCS11Provider },
  { "smartcarddevice", oPKCS11Provider },
# else
  { "smartcarddevice", oUnsupported },
  { "pkcs11provider", oUnsupported },
#endif

  { "forwardagent", oForwardAgent },
  { "forwardx11", oForwardX11 },
  { "forwardx11trusted", oForwardX11Trusted },
  { "forwardx11timeout", oForwardX11Timeout },
  { "exitonforwardfailure", oExitOnForwardFailure },
  { "xauthlocation", oXAuthLocation },
  { "gatewayports", oGatewayPorts },
  { "passwordauthentication", oPasswordAuthentication },
  { "kbdinteractiveauthentication", oKbdInteractiveAuthentication },
  { "kbdinteractivedevices", oKbdInteractiveDevices },
  { "challengeresponseauthentication", oKbdInteractiveAuthentication }, /* alias */
  { "skeyauthentication", oKbdInteractiveAuthentication }, /* alias */
  { "tisauthentication", oKbdInteractiveAuthentication },  /* alias */
  { "pubkeyauthentication", oPubkeyAuthentication },
  { "dsaauthentication", oPubkeyAuthentication },       /* alias */
  { "hostbasedauthentication", oHostbasedAuthentication },
  { "identityfile", oIdentityFile },
  { "identityfile2", oIdentityFile },     /* obsolete */
  { "identitiesonly", oIdentitiesOnly },
  { "certificatefile", oCertificateFile },
  { "addkeystoagent", oAddKeysToAgent },
  { "identityagent", oIdentityAgent },
  { "hostname", oHostname },
  { "hostkeyalias", oHostKeyAlias },
  { "proxycommand", oProxyCommand },
  { "port", oPort },
  { "ciphers", oCiphers },
  { "macs", oMacs },
  { "remoteforward", oRemoteForward },
  { "localforward", oLocalForward },
  { "permitremoteopen", oPermitRemoteOpen },
  { "user", oUser },
  { "host", oHost },
  { "match", oMatch },
  { "tag", oTag },
  { "escapechar", oEscapeChar },
  { "globalknownhostsfile", oGlobalKnownHostsFile },
  { "userknownhostsfile", oUserKnownHostsFile },
  { "connectionattempts", oConnectionAttempts },
  { "batchmode", oBatchMode },
  { "checkhostip", oCheckHostIP },
  { "stricthostkeychecking", oStrictHostKeyChecking },
  { "compression", oCompression },
  { "tcpkeepalive", oTCPKeepAlive },
  { "keepalive", oTCPKeepAlive },       /* obsolete */
  { "numberofpasswordprompts", oNumberOfPasswordPrompts },
  { "syslogfacility", oLogFacility },
  { "loglevel", oLogLevel },
  { "logverbose", oLogVerbose },
  { "dynamicforward", oDynamicForward },
  { "preferredauthentications", oPreferredAuthentications },
  { "hostkeyalgorithms", oHostKeyAlgorithms },
  { "casignaturealgorithms", oCASignatureAlgorithms },
  { "bindaddress", oBindAddress },
  { "bindinterface", oBindInterface },
  { "clearallforwardings", oClearAllForwardings },
  { "enablesshkeysign", oEnableSSHKeysign },
  { "verifyhostkeydns", oVerifyHostKeyDNS },
  { "nohostauthenticationforlocalhost", oNoHostAuthenticationForLocalhost },
  { "rekeylimit", oRekeyLimit },
  { "connecttimeout", oConnectTimeout },
  { "addressfamily", oAddressFamily },
  { "serveraliveinterval", oServerAliveInterval },
  { "serveralivecountmax", oServerAliveCountMax },
  { "sendenv", oSendEnv },
  { "setenv", oSetEnv },
  { "controlpath", oControlPath },
  { "controlmaster", oControlMaster },
  { "controlpersist", oControlPersist },
  { "hashknownhosts", oHashKnownHosts },
  { "include", oInclude },
  { "tunnel", oTunnel },
  { "tunneldevice", oTunnelDevice },
  { "localcommand", oLocalCommand },
  { "permitlocalcommand", oPermitLocalCommand },
  { "remotecommand", oRemoteCommand },
  { "visualhostkey", oVisualHostKey },
  { "kexalgorithms", oKexAlgorithms },
  { "ipqos", oIPQoS },
  { "requesttty", oRequestTTY },
  { "sessiontype", oSessionType },
  { "stdinnull", oStdinNull },
  { "forkafterauthentication", oForkAfterAuthentication },
  { "proxyusefdpass", oProxyUseFdpass },
  { "canonicaldomains", oCanonicalDomains },
  { "canonicalizefallbacklocal", oCanonicalizeFallbackLocal },
  { "canonicalizehostname", oCanonicalizeHostname },
  { "canonicalizemaxdots", oCanonicalizeMaxDots },
  { "canonicalizepermittedcnames", oCanonicalizePermittedCNAMEs },
  { "streamlocalbindmask", oStreamLocalBindMask },
  { "streamlocalbindunlink", oStreamLocalBindUnlink },
  { "revokedhostkeys", oRevokedHostKeys },
  { "fingerprinthash", oFingerprintHash },
  { "updatehostkeys", oUpdateHostkeys },
  { "hostbasedacceptedalgorithms", oHostbasedAcceptedAlgorithms },
  { "hostbasedkeytypes", oHostbasedAcceptedAlgorithms }, /* obsolete */
  { "pubkeyacceptedalgorithms", oPubkeyAcceptedAlgorithms },
  { "pubkeyacceptedkeytypes", oPubkeyAcceptedAlgorithms }, /* obsolete */
  { "ignoreunknown", oIgnoreUnknown },
  { "proxyjump", oProxyJump },
  { "securitykeyprovider", oSecurityKeyProvider },
  { "knownhostscommand", oKnownHostsCommand },
  { "requiredrsasize", oRequiredRSASize },
  { "enableescapecommandline", oEnableEscapeCommandline },
  { "obscurekeystroketiming", oObscureKeystrokeTiming },
  { "channeltimeout", oChannelTimeout },
  { "versionaddendum", oVersionAddendum },
  { "refuseconnection", oRefuseConnection },
  { "warnweakcrypto", oWarnWeakCrypto },

  { NULL, oBadOption }
};

static const char *lookup_opcode_name(OpCodes code);

const char *
kex_default_pk_alg(void)
{
  static char *pkalgs;

  if (pkalgs == NULL) {
    char *all_key;

    all_key = sshkey_alg_list(0, 0, 1, ',');
    pkalgs = match_filter_allowlist(KEX_DEFAULT_PK_ALG, all_key);
    free(all_key);
  }
  return pkalgs;
}

char *
ssh_connection_hash(const char *thishost, const char *host, const char *portstr,
    const char *user, const char *jumphost)
{
  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_update(md, jumphost, strlen(jumphost)) < 0 ||
      ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0)
    fatal_f("mux digest failed");
  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.
 */

void
add_local_forward(Options *options, const struct Forward *newfwd)
{
  struct Forward *fwd;
  int i;

  /* Don't add duplicates */
  for (i = 0; i < options->num_local_forwards; i++) {
    if (forward_equals(newfwd, options->local_forwards + i))
      return;
  }
  options->local_forwards = xreallocarray(options->local_forwards,
      options->num_local_forwards + 1,
      sizeof(*options->local_forwards));
  fwd = &options->local_forwards[options->num_local_forwards++];

  fwd->listen_host = newfwd->listen_host;
  fwd->listen_port = newfwd->listen_port;
  fwd->listen_path = newfwd->listen_path;
  fwd->connect_host = newfwd->connect_host;
  fwd->connect_port = newfwd->connect_port;
  fwd->connect_path = newfwd->connect_path;
}

/*
 * Adds a remote TCP/IP port forward to options.  Never returns if there is
 * an error.
 */

void
add_remote_forward(Options *options, const struct Forward *newfwd)
{
  struct Forward *fwd;
  int i;

  /* Don't add duplicates */
  for (i = 0; i < options->num_remote_forwards; i++) {
    if (forward_equals(newfwd, options->remote_forwards + i))
      return;
  }
  options->remote_forwards = xreallocarray(options->remote_forwards,
      options->num_remote_forwards + 1,
      sizeof(*options->remote_forwards));
  fwd = &options->remote_forwards[options->num_remote_forwards++];

  fwd->listen_host = newfwd->listen_host;
  fwd->listen_port = newfwd->listen_port;
  fwd->listen_path = newfwd->listen_path;
  fwd->connect_host = newfwd->connect_host;
  fwd->connect_port = newfwd->connect_port;
  fwd->connect_path = newfwd->connect_path;
  fwd->handle = newfwd->handle;
  fwd->allocated_port = 0;
}

static void
clear_forwardings(Options *options)
{
  int i;

  for (i = 0; i < options->num_local_forwards; i++) {
    free(options->local_forwards[i].listen_host);
    free(options->local_forwards[i].listen_path);
    free(options->local_forwards[i].connect_host);
    free(options->local_forwards[i].connect_path);
  }
  if (options->num_local_forwards > 0) {
    free(options->local_forwards);
    options->local_forwards = NULL;
  }
  options->num_local_forwards = 0;
  for (i = 0; i < options->num_remote_forwards; i++) {
    free(options->remote_forwards[i].listen_host);
    free(options->remote_forwards[i].listen_path);
    free(options->remote_forwards[i].connect_host);
    free(options->remote_forwards[i].connect_path);
  }
  if (options->num_remote_forwards > 0) {
    free(options->remote_forwards);
    options->remote_forwards = NULL;
  }
  options->num_remote_forwards = 0;
  options->tun_open = SSH_TUNMODE_NO;
}

void
add_certificate_file(Options *options, const char *path, int userprovided)
{
  int i;

  if (options->num_certificate_files >= SSH_MAX_CERTIFICATE_FILES)
    fatal("Too many certificate files specified (max %d)",
        SSH_MAX_CERTIFICATE_FILES);

  /* Avoid registering duplicates */
  for (i = 0; i < options->num_certificate_files; i++) {
    if (options->certificate_file_userprovided[i] == userprovided &&
        strcmp(options->certificate_files[i], path) == 0) {
      debug2_f("ignoring duplicate key %s", path);
      return;
    }
  }

  options->certificate_file_userprovided[options->num_certificate_files] =
      userprovided;
  options->certificate_files[options->num_certificate_files++] =
      xstrdup(path);
}

void
add_identity_file(Options *options, const char *dir, const char *filename,
    int userprovided)
{
  char *path;
  int i;

  if (options->num_identity_files >= SSH_MAX_IDENTITY_FILES)
    fatal("Too many identity files specified (max %d)",
        SSH_MAX_IDENTITY_FILES);

  if (dir == NULL) /* no dir, filename is absolute */
    path = xstrdup(filename);
  else if (xasprintf(&path, "%s%s", dir, filename) >= PATH_MAX)
    fatal("Identity file path %s too long", path);

  /* Avoid registering duplicates */
  for (i = 0; i < options->num_identity_files; i++) {
    if (options->identity_file_userprovided[i] == userprovided &&
        strcmp(options->identity_files[i], path) == 0) {
      debug2_f("ignoring duplicate key %s", path);
      free(path);
      return;
    }
  }

  options->identity_file_userprovided[options->num_identity_files] =
      userprovided;
  options->identity_files[options->num_identity_files++] = path;
}

int
default_ssh_port(void)
{
  static int port;
  struct servent *sp;

  if (port == 0) {
    sp = getservbyname(SSH_SERVICE_NAME, "tcp");
    port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
  }
  return port;
}

/*
 * Execute a command in a shell.
 * Return its exit status or -1 on abnormal exit.
 */
static int
execute_in_shell(const char *cmd)
{
  char *shell;
  pid_t pid;
  int status;

  if ((shell = getenv("SHELL")) == NULL)
    shell = _PATH_BSHELL;

  if (access(shell, X_OK) == -1) {
    fatal("Shell \"%s\" is not executable: %s",
        shell, strerror(errno));
  }

  debug("Executing command: '%.500s'", cmd);

  /* Fork and execute the command. */
  if ((pid = fork()) == 0) {
    char *argv[4];

    if (stdfd_devnull(1, 1, 0) == -1)
      fatal_f("stdfd_devnull failed");
    closefrom(STDERR_FILENO + 1);

    argv[0] = shell;
    argv[1] = "-c";
    argv[2] = xstrdup(cmd);
    argv[3] = NULL;

    execv(argv[0], argv);
    error("Unable to execute '%.100s': %s", cmd, strerror(errno));
    /* Die with signal to make this error apparent to parent. */
    ssh_signal(SIGTERM, SIG_DFL);
    kill(getpid(), SIGTERM);
    _exit(1);
  }
  /* Parent. */
  if (pid == -1)
    fatal_f("fork: %.100s", strerror(errno));

  while (waitpid(pid, &status, 0) == -1) {
    if (errno != EINTR && errno != EAGAIN)
      fatal_f("waitpid: %s", strerror(errno));
  }
  if (!WIFEXITED(status)) {
    error("command '%.100s' exited abnormally", cmd);
    return -1;
  }
  debug3("command returned status %d", WEXITSTATUS(status));
  return WEXITSTATUS(status);
}

/*
 * Check whether a local network interface address appears in CIDR pattern-
 * list 'addrlist'. Returns 1 if matched or 0 otherwise.
 */
static int
check_match_ifaddrs(const char *addrlist)
{
#ifdef HAVE_IFADDRS_H
  struct ifaddrs *ifa, *ifaddrs = NULL;
  int r, found = 0;
  char addr[NI_MAXHOST];
  socklen_t salen;

  if (getifaddrs(&ifaddrs) != 0) {
    error("match localnetwork: getifaddrs failed: %s",
        strerror(errno));
    return 0;
  }
  for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) {
    if (ifa->ifa_addr == NULL || ifa->ifa_name == NULL ||
        (ifa->ifa_flags & IFF_UP) == 0)
      continue;
    switch (ifa->ifa_addr->sa_family) {
    case AF_INET:
      salen = sizeof(struct sockaddr_in);
      break;
    case AF_INET6:
      salen = sizeof(struct sockaddr_in6);
      break;
#ifdef AF_LINK
    case AF_LINK:
      /* ignore */
      continue;
#endif /* AF_LINK */
    default:
      debug2_f("interface %s: unsupported address family %d",
          ifa->ifa_name, ifa->ifa_addr->sa_family);
      continue;
    }
    if ((r = getnameinfo(ifa->ifa_addr, salen, addr, sizeof(addr),
        NULL, 0, NI_NUMERICHOST)) != 0) {
      debug2_f("interface %s getnameinfo failed: %s",
          ifa->ifa_name, gai_strerror(r));
      continue;
    }
    debug3_f("interface %s addr %s", ifa->ifa_name, addr);
    if (addr_match_cidr_list(addr, addrlist) == 1) {
      debug3_f("matched interface %s: address %s in %s",
          ifa->ifa_name, addr, addrlist);
      found = 1;
      break;
    }
  }
  freeifaddrs(ifaddrs);
  return found;
#else /* HAVE_IFADDRS_H */
  error("match localnetwork: not supported on this platform");
  return 0;
#endif /* HAVE_IFADDRS_H */
}

/*
 * Expand a "match exec" command or an Include path, caller must free returned
 * value.
 */
static char *
expand_match_exec_or_include_path(const char *path, Options *options,
    struct passwd *pw, const char *host_arg, const char *original_host,
    int final_pass, int is_include_path)
{
  char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
  char uidstr[32], *conn_hash_hex, *keyalias, *jmphost, *ruser;
  char *host, *ret;
  int port;

  port = options->port <= 0 ? default_ssh_port() : options->port;
  ruser = options->user == NULL ? pw->pw_name : options->user;
  if (final_pass) {
    host = xstrdup(options->hostname);
  } else if (options->hostname != NULL) {
    /* NB. Please keep in sync with ssh.c:main() */
    host = percent_expand(options->hostname,
        "h", host_arg, (char *)NULL);
  } else {
    host = xstrdup(host_arg);
  }
  if (gethostname(thishost, sizeof(thishost)) == -1)
    fatal("gethostname: %s", strerror(errno));
  jmphost = option_clear_or_none(options->jump_host) ?
      "" : options->jump_host;
  strlcpy(shorthost, thishost, sizeof(shorthost));
  shorthost[strcspn(thishost, ".")] = '\0';
  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, ruser, jmphost);
  keyalias = options->host_key_alias ?  options->host_key_alias : host;

  ret = (is_include_path ? percent_dollar_expand : percent_expand)(path,
      "C", conn_hash_hex,
      "L", shorthost,
      "d", pw->pw_dir,
      "h", host,
      "k", keyalias,
      "l", thishost,
      "n", original_host,
      "p", portstr,
      "r", ruser,
      "u", pw->pw_name,
      "i", uidstr,
      "j", jmphost,
      (char *)NULL);
  free(host);
  free(conn_hash_hex);
  return ret;
}

/*
 * Parse and execute a Match directive.
 */
static int
match_cfg_line(Options *options, const char *full_line, int *acp, char ***avp,
    struct passwd *pw, const char *host_arg, const char *original_host,
    const char *remote_command, int final_pass, int *want_final_pass,
    const char *filename, int linenum)
{
  char *arg, *oattrib = NULL, *attrib = NULL, *cmd, *host, *criteria;
  const char *ruser;
  int r, this_result, result = 1, attributes = 0, negate;

  /*
   * Configuration is likely to be incomplete at this point so we
   * must be prepared to use default values.
   */
  ruser = options->user == NULL ? pw->pw_name : options->user;
  if (final_pass) {
    host = xstrdup(options->hostname);
  } else if (options->hostname != NULL) {
    /* NB. Please keep in sync with ssh.c:main() */
    host = percent_expand(options->hostname,
        "h", host_arg, (char *)NULL);
  } else {
    host = xstrdup(host_arg);
  }

  debug2("checking match for '%s' host %s originally %s",
      full_line, host, original_host);
  while ((attrib = argv_next(acp, avp)) != NULL) {
    /* Terminate on comment */
    if (*attrib == '#') {
      argv_consume(acp);
      break;
    }
    attrib = oattrib = xstrdup(attrib);
    arg = criteria = NULL;
    this_result = 1;
    if ((negate = (attrib[0] == '!')))
      attrib++;
    /* Criterion "all" has no argument and must appear alone */
    if (strcasecmp(attrib, "all") == 0) {
      if (attributes > 1 ||
          ((arg = argv_next(acp, avp)) != NULL &&
          *arg != '\0' && *arg != '#')) {
        error("%.200s line %d: '%s' cannot be combined "
            "with other Match attributes",
            filename, linenum, oattrib);
        result = -1;
        goto out;
      }
      if (arg != NULL && *arg == '#')
        argv_consume(acp); /* consume remaining args */
      if (result)
        result = negate ? 0 : 1;
      goto out;
    }
    attributes++;
    /* criteria "final" and "canonical" have no argument */
    if (strcasecmp(attrib, "canonical") == 0 ||
        strcasecmp(attrib, "final") == 0) {
      /*
       * If the config requests "Match final" without
       * negation then remember this so we can perform a
       * second pass later.
       */
      if (strcasecmp(attrib, "final") == 0 &&
          want_final_pass != NULL)
        *want_final_pass |= !negate;
      r = !!final_pass;  /* 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);
      goto next;
    }

    /* Keep this list in sync with below */
    if (strprefix(attrib, "host=", 1)  != NULL ||
        strprefix(attrib, "originalhost=", 1) != NULL ||
        strprefix(attrib, "user=", 1) != NULL ||
        strprefix(attrib, "localuser=", 1) != NULL ||
        strprefix(attrib, "localnetwork=", 1) != NULL ||
        strprefix(attrib, "version=", 1) != NULL ||
        strprefix(attrib, "tagged=", 1) != NULL ||
        strprefix(attrib, "command=", 1) != NULL ||
        strprefix(attrib, "exec=", 1) != NULL) {
      arg = strchr(attrib, '=');
      *(arg++) = '\0';
    } else if ((arg = argv_next(acp, avp)) == NULL) {
      error("%.200s line %d: missing argument for Match '%s'",
          filename, linenum, oattrib);
      result = -1;
      goto out;
    }

    /*
     * All other criteria require an argument, though it may
     * be the empty string for the "tagged" and "command"
     * options.
     */
    if (*arg == '\0' &&
        strcasecmp(attrib, "tagged") != 0 &&
        strcasecmp(attrib, "command") != 0)
      arg = NULL;
    if (arg == NULL || *arg == '#') {
      error("Missing Match criteria for %s", attrib);
      result = -1;
      goto out;
    }
    if (strcasecmp(attrib, "host") == 0) {
      criteria = xstrdup(host);
      r = match_hostname(host, arg) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "originalhost") == 0) {
      criteria = xstrdup(original_host);
      r = match_hostname(original_host, arg) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "user") == 0) {
      criteria = xstrdup(ruser);
      r = match_pattern_list(ruser, arg, 0) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "localuser") == 0) {
      criteria = xstrdup(pw->pw_name);
      r = match_pattern_list(pw->pw_name, arg, 0) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "localnetwork") == 0) {
      if (addr_match_cidr_list(NULL, arg) == -1) {
        /* Error already printed */
        result = -1;
        goto out;
      }
      r = check_match_ifaddrs(arg) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "version") == 0) {
      criteria = xstrdup(SSH_RELEASE);
      r = match_pattern_list(SSH_RELEASE, arg, 0) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "tagged") == 0) {
      criteria = xstrdup(options->tag == NULL ? "" :
          options->tag);
      /* Special case: empty criteria matches empty arg */
      r = (*criteria == '\0') ? *arg == '\0' :
          match_pattern_list(criteria, arg, 0) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "command") == 0) {
      criteria = xstrdup(remote_command == NULL ?
          "" : remote_command);
      /* Special case: empty criteria matches empty arg */
      r = (*criteria == '\0') ? *arg == '\0' :
          match_pattern_list(criteria, arg, 0) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "sessiontype") == 0) {
      if (options->session_type == SESSION_TYPE_SUBSYSTEM)
        criteria = xstrdup("subsystem");
      else if (options->session_type == SESSION_TYPE_NONE)
        criteria = xstrdup("none");
      else if (remote_command != NULL &&
          *remote_command != '\0')
        criteria = xstrdup("exec");
      else
        criteria = xstrdup("shell");
      r = match_pattern_list(criteria, arg, 0) == 1;
      if (r == (negate ? 1 : 0))
        this_result = result = 0;
    } else if (strcasecmp(attrib, "exec") == 0) {
      if ((cmd = expand_match_exec_or_include_path(arg,
          options, pw, host_arg, original_host,
          final_pass, 0)) == NULL) {
        fatal("%.200s line %d: failed to expand match "
            "exec '%.100s'", filename, linenum, arg);
      }
      if (result != 1) {
        /* skip execution if prior predicate failed */
        debug3("%.200s line %d: skipped exec "
            "\"%.100s\"", filename, linenum, cmd);
        free(cmd);
        goto next;
      }
      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%s%.100s%s' ",
        filename, linenum, this_result ? "": "not ", oattrib,
        criteria == NULL ? "" : " \"",
        criteria == NULL ? "" : criteria,
        criteria == NULL ? "" : "\"");
 next:
    free(criteria);
    free(oattrib);
    oattrib = attrib = NULL;
  }
  if (attributes == 0) {
    error("One or more attributes required for Match");
    result = -1;
    goto out;
  }
 out:
  if (result != -1)
    debug2("match %sfound", result ? "" : "not ");
  free(oattrib);
  free(host);
  return result;
}

/* Remove environment variable by pattern */
static void
rm_env(Options *options, const char *arg, const char *filename, int linenum)
{
  u_int i, j, onum_send_env = options->num_send_env;

  /* Remove an environment variable */
  for (i = 0; i < options->num_send_env; ) {
    if (!match_pattern(options->send_env[i], arg + 1)) {
      i++;
      continue;
    }
    debug3("%s line %d: removing environment %s",
        filename, linenum, options->send_env[i]);
    free(options->send_env[i]);
    options->send_env[i] = NULL;
    for (j = i; j < options->num_send_env - 1; j++) {
      options->send_env[j] = options->send_env[j + 1];
      options->send_env[j + 1] = NULL;
    }
    options->num_send_env--;
    /* NB. don't increment i */
  }
  if (onum_send_env != options->num_send_env) {
    options->send_env = xrecallocarray(options->send_env,
        onum_send_env, options->num_send_env,
        sizeof(*options->send_env));
  }
}

/*
 * Returns the number of the token pointed to by cp or oBadOption.
 */
static OpCodes
parse_token(const char *cp, const char *filename, int linenum,
    const char *ignored_unknown)
{
  int i;

  for (i = 0; keywords[i].name; i++)
    if (strcmp(cp, keywords[i].name) == 0)
      return keywords[i].opcode;
  if (ignored_unknown != NULL &&
      match_pattern_list(cp, ignored_unknown, 1) == 1)
    return oIgnoredUnknownOption;
  error("%s: line %d: Bad configuration option: %s",
      filename, linenum, cp);
  return oBadOption;
}

static void
free_canon_cnames(struct allowed_cname *cnames, u_int n)
{
  u_int i;

  if (cnames == NULL || n == 0)
    return;
  for (i = 0; i < n; i++) {
    free(cnames[i].source_list);
    free(cnames[i].target_list);
  }
  free(cnames);
}

/* Multistate option parsing */
struct multistate {
  char *key;
  int value;
};
static const struct multistate multistate_flag[] = {
  { "true",     1 },
  { "false",      0 },
  { "yes",      1 },
  { "no",       0 },
  { NULL, -1 }
};
static const struct multistate multistate_yesnoask[] = {
  { "true",     1 },
  { "false",      0 },
  { "yes",      1 },
  { "no",       0 },
  { "ask",      2 },
  { NULL, -1 }
};
static const struct multistate multistate_strict_hostkey[] = {
  { "true",     SSH_STRICT_HOSTKEY_YES },
  { "false",      SSH_STRICT_HOSTKEY_OFF },
  { "yes",      SSH_STRICT_HOSTKEY_YES },
  { "no",       SSH_STRICT_HOSTKEY_OFF },
  { "ask",      SSH_STRICT_HOSTKEY_ASK },
  { "off",      SSH_STRICT_HOSTKEY_OFF },
  { "accept-new",     SSH_STRICT_HOSTKEY_NEW },
  { NULL, -1 }
};
static const struct multistate multistate_yesnoaskconfirm[] = {
  { "true",     1 },
  { "false",      0 },
  { "yes",      1 },
  { "no",       0 },
  { "ask",      2 },
  { "confirm",      3 },
  { NULL, -1 }
};
static const struct multistate multistate_addressfamily[] = {
  { "inet",     AF_INET },
  { "inet6",      AF_INET6 },
  { "any",      AF_UNSPEC },
  { NULL, -1 }
};
static const struct multistate multistate_controlmaster[] = {
  { "true",     SSHCTL_MASTER_YES },
  { "yes",      SSHCTL_MASTER_YES },
  { "false",      SSHCTL_MASTER_NO },
  { "no",       SSHCTL_MASTER_NO },
  { "auto",     SSHCTL_MASTER_AUTO },
  { "ask",      SSHCTL_MASTER_ASK },
  { "autoask",      SSHCTL_MASTER_AUTO_ASK },
  { NULL, -1 }
};
static const struct multistate multistate_tunnel[] = {
  { "ethernet",     SSH_TUNMODE_ETHERNET },
  { "point-to-point",   SSH_TUNMODE_POINTOPOINT },
  { "true",     SSH_TUNMODE_DEFAULT },
  { "yes",      SSH_TUNMODE_DEFAULT },
  { "false",      SSH_TUNMODE_NO },
  { "no",       SSH_TUNMODE_NO },
  { NULL, -1 }
};
static const struct multistate multistate_requesttty[] = {
  { "true",     REQUEST_TTY_YES },
  { "yes",      REQUEST_TTY_YES },
  { "false",      REQUEST_TTY_NO },
  { "no",       REQUEST_TTY_NO },
  { "force",      REQUEST_TTY_FORCE },
  { "auto",     REQUEST_TTY_AUTO },
  { NULL, -1 }
};
static const struct multistate multistate_sessiontype[] = {
  { "none",     SESSION_TYPE_NONE },
  { "subsystem",      SESSION_TYPE_SUBSYSTEM },
  { "default",      SESSION_TYPE_DEFAULT },
  { NULL, -1 }
};
static const struct multistate multistate_canonicalizehostname[] = {
  { "true",     SSH_CANONICALISE_YES },
  { "false",      SSH_CANONICALISE_NO },
  { "yes",      SSH_CANONICALISE_YES },
  { "no",       SSH_CANONICALISE_NO },
  { "always",     SSH_CANONICALISE_ALWAYS },
  { NULL, -1 }
};
static const struct multistate multistate_pubkey_auth[] = {
  { "true",     SSH_PUBKEY_AUTH_ALL },
  { "false",      SSH_PUBKEY_AUTH_NO },
  { "yes",      SSH_PUBKEY_AUTH_ALL },
  { "no",       SSH_PUBKEY_AUTH_NO },
  { "unbound",      SSH_PUBKEY_AUTH_UNBOUND },
  { "host-bound",     SSH_PUBKEY_AUTH_HBOUND },
  { NULL, -1 }
};
static const struct multistate multistate_compression[] = {
#ifdef WITH_ZLIB
  { "yes",      COMP_DELAYED },
#endif
  { "no",       COMP_NONE },
  { NULL, -1 }
};
static const struct multistate multistate_keepalives[] = {
  { "true",     SSH_KEEPALIVES_TRANSPORT },
  { "false",      SSH_KEEPALIVES_OFF },
  { "yes",      SSH_KEEPALIVES_TRANSPORT },
  { "no",       SSH_KEEPALIVES_OFF },
  { "transport",      SSH_KEEPALIVES_TRANSPORT },
  { "all",      SSH_KEEPALIVES_ALL },
  { NULL, -1 }
};
/* XXX this will need to be replaced with a bitmask if we add more flags */
static const struct multistate multistate_warnweakcrypto[] = {
  { "true",     1 },
  { "false",      0 },
  { "yes",      1 },
  { "no",       0 },
  { "no-pq-kex",      0 },
  { NULL, -1 }
};

static int
parse_multistate_value(const char *arg, const char *filename, int linenum,
    const struct multistate *multistate_ptr)
{
  int i;

  if (!arg || *arg == '\0') {
    error("%s line %d: missing argument.", filename, linenum);
    return -1;
  }
  for (i = 0; multistate_ptr[i].key != NULL; i++) {
    if (strcasecmp(arg, multistate_ptr[i].key) == 0)
      return multistate_ptr[i].value;
  }
  return -1;
}

/*
 * Processes a single option line as used in the configuration files. This
 * only sets those values that have not already been set.
 */
int
process_config_line(Options *options, struct passwd *pw, const char *host,
    const char *original_host, const char *remote_command, char *line,
    const char *filename, int linenum, int *activep, int flags)
{
  return process_config_line_depth(options, pw, host, original_host,
      remote_command, line, filename, linenum, activep, flags, NULL, 0);
}

#define WHITESPACE " \t\r\n"
static int
process_config_line_depth(Options *options, struct passwd *pw, const char *host,
    const char *original_host, const char *remote_command, char *line,
    const char *filename, int linenum, int *activep, int flags,
    int *want_final_pass, int depth)
{
  char *str, **charptr, *endofnumber, *keyword, *arg, *arg2, *p;
  char **cpptr, ***cppptr, fwdarg[256];
  u_int i, *uintptr, max_entries = 0;
  int r, oactive, negated, opcode, *intptr, value, value2, cmdline = 0;
  int remotefwd, dynamicfwd, ca_only = 0, found = 0;
  LogLevel *log_level_ptr;
  SyslogFacility *log_facility_ptr;
  long long val64;
  size_t len;
  struct Forward fwd;
  const struct multistate *multistate_ptr;
  glob_t gl;
  const char *errstr;
  char **oav = NULL, **av;
  int oac = 0, ac;
  int ret = -1;
  struct allowed_cname *cnames = NULL;
  u_int ncnames = 0;
  char **strs = NULL; /* string array arguments; freed implicitly */
  u_int nstrs = 0;

  if (activep == NULL) { /* We are processing a command line directive */
    cmdline = 1;
    activep = &cmdline;
  }

  /* Strip trailing whitespace. Allow \f (form feed) at EOL only */
  if ((len = strlen(line)) == 0)
    return 0;
  for (len--; len > 0; len--) {
    if (strchr(WHITESPACE "\f", line[len]) == NULL)
      break;
    line[len] = '\0';
  }

  str = line;
  /* Get the keyword. (Each line is supposed to begin with a keyword). */
  if ((keyword = strdelim(&str)) == NULL)
    return 0;
  /* Ignore leading whitespace. */
  if (*keyword == '\0')
    keyword = strdelim(&str);
  if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#')
    return 0;
  /* Match lowercase keyword */
  lowercase(keyword);

  /* Prepare to parse remainder of line */
  if (str != NULL)
    str += strspn(str, WHITESPACE);
  if (str == NULL || *str == '\0') {
    error("%s line %d: no argument after keyword \"%s\"",
        filename, linenum, keyword);
    return -1;
  }
  opcode = parse_token(keyword, filename, linenum,
      options->ignored_unknown);
  if (argv_split(str, &oac, &oav, 1) != 0) {
    error("%s line %d: invalid quotes", filename, linenum);
    return -1;
  }
  ac = oac;
  av = oav;

  switch (opcode) {
  case oBadOption:
    /* don't panic, but count bad options */
    goto out;
  case oIgnore:
    argv_consume(&ac);
    break;
  case oIgnoredUnknownOption:
    debug("%s line %d: Ignored unknown option \"%s\"",
        filename, linenum, keyword);
    argv_consume(&ac);
    break;
  case oConnectTimeout:
    intptr = &options->connection_timeout;
parse_time:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%s line %d: missing time value.",
          filename, linenum);
      goto out;
    }
    if (strcmp(arg, "none") == 0)
      value = -1;
    else if ((value = convtime(arg)) == -1) {
      error("%s line %d: invalid time value.",
          filename, linenum);
      goto out;
    }
    if (*activep && *intptr == -1)
      *intptr = value;
    break;

  case oForwardAgent:
    intptr = &options->forward_agent;

    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%s line %d: missing argument.",
          filename, linenum);
      goto out;
    }

    value = -1;
    multistate_ptr = multistate_flag;
    for (i = 0; multistate_ptr[i].key != NULL; i++) {
      if (strcasecmp(arg, multistate_ptr[i].key) == 0) {
        value = multistate_ptr[i].value;
        break;
      }
    }
    if (value != -1) {
      if (*activep && *intptr == -1)
        *intptr = value;
      break;
    }
    /* ForwardAgent wasn't 'yes' or 'no', assume a path */
    if (*activep && *intptr == -1)
      *intptr = 1;

    charptr = &options->forward_agent_sock_path;
    goto parse_agent_path;

  case oForwardX11:
    intptr = &options->forward_x11;
 parse_flag:
    multistate_ptr = multistate_flag;
 parse_multistate:
    arg = argv_next(&ac, &av);
    if ((value = parse_multistate_value(arg, filename, linenum,
        multistate_ptr)) == -1) {
      error("%s line %d: unsupported option \"%s\".",
          filename, linenum, arg);
      goto out;
    }
    if (*activep && *intptr == -1)
      *intptr = value;
    break;

  case oForwardX11Trusted:
    intptr = &options->forward_x11_trusted;
    goto parse_flag;

  case oForwardX11Timeout:
    intptr = &options->forward_x11_timeout;
    goto parse_time;

  case oGatewayPorts:
    intptr = &options->fwd_opts.gateway_ports;
    goto parse_flag;

  case oExitOnForwardFailure:
    intptr = &options->exit_on_forward_failure;
    goto parse_flag;

  case oPasswordAuthentication:
    intptr = &options->password_authentication;
    goto parse_flag;

  case oKbdInteractiveAuthentication:
    intptr = &options->kbd_interactive_authentication;
    goto parse_flag;

  case oKbdInteractiveDevices:
    charptr = &options->kbd_interactive_devices;
    goto parse_string;

  case oPubkeyAuthentication:
    multistate_ptr = multistate_pubkey_auth;
    intptr = &options->pubkey_authentication;
    goto parse_multistate;

  case oHostbasedAuthentication:
    intptr = &options->hostbased_authentication;
    goto parse_flag;

  case oGssAuthentication:
    intptr = &options->gss_authentication;
    goto parse_flag;

  case oGssDelegateCreds:
    intptr = &options->gss_deleg_creds;
    goto parse_flag;

  case oBatchMode:
    intptr = &options->batch_mode;
    goto parse_flag;

  case oCheckHostIP:
    intptr = &options->check_host_ip;
    goto parse_flag;

  case oVerifyHostKeyDNS:
    intptr = &options->verify_host_key_dns;
    multistate_ptr = multistate_yesnoask;
    goto parse_multistate;

  case oStrictHostKeyChecking:
    intptr = &options->strict_host_key_checking;
    multistate_ptr = multistate_strict_hostkey;
    goto parse_multistate;

  case oCompression:
    intptr = &options->compression;
    multistate_ptr = multistate_compression;
    goto parse_multistate;

  case oTCPKeepAlive:
    intptr = &options->tcp_keep_alive;
    multistate_ptr = multistate_keepalives;
    goto parse_multistate;

  case oNoHostAuthenticationForLocalhost:
    intptr = &options->no_host_authentication_for_localhost;
    goto parse_flag;

  case oNumberOfPasswordPrompts:
    intptr = &options->number_of_password_prompts;
    goto parse_int;

  case oRekeyLimit:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.", filename,
          linenum);
      goto out;
    }
    if (strcmp(arg, "default") == 0) {
      val64 = 0;
    } else {
      if (scan_scaled(arg, &val64) == -1) {
        error("%.200s line %d: Bad number '%s': %s",
            filename, linenum, arg, strerror(errno));
        goto out;
      }
      if (val64 != 0 && val64 < 16) {
        error("%.200s line %d: RekeyLimit too small",
            filename, linenum);
        goto out;
      }
    }
    if (*activep && options->rekey_limit == -1)
      options->rekey_limit = val64;
    if (ac != 0) { /* optional rekey interval present */
      if (strcmp(av[0], "none") == 0) {
        (void)argv_next(&ac, &av);  /* discard */
        break;
      }
      intptr = &options->rekey_interval;
      goto parse_time;
    }
    break;

  case oIdentityFile:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*activep) {
      intptr = &options->num_identity_files;
      if (*intptr >= SSH_MAX_IDENTITY_FILES) {
        error("%.200s line %d: Too many identity files "
            "specified (max %d).", filename, linenum,
            SSH_MAX_IDENTITY_FILES);
        goto out;
      }
      add_identity_file(options, NULL,
          arg, flags & SSHCONF_USERCONF);
    }
    break;

  case oCertificateFile:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*activep) {
      intptr = &options->num_certificate_files;
      if (*intptr >= SSH_MAX_CERTIFICATE_FILES) {
        error("%.200s line %d: Too many certificate "
            "files specified (max %d).",
            filename, linenum,
            SSH_MAX_CERTIFICATE_FILES);
        goto out;
      }
      add_certificate_file(options, arg,
          flags & SSHCONF_USERCONF);
    }
    break;

  case oXAuthLocation:
    charptr=&options->xauth_location;
    goto parse_string;

  case oUser:
    charptr = &options->user;
parse_string:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*activep && *charptr == NULL)
      *charptr = xstrdup(arg);
    break;

  case oGlobalKnownHostsFile:
    cpptr = (char **)&options->system_hostfiles;
    uintptr = &options->num_system_hostfiles;
    max_entries = SSH_MAX_HOSTS_FILES;
parse_char_array:
    i = 0;
    value = *uintptr == 0; /* was array empty when we started? */
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (*arg == '\0') {
        error("%s line %d: keyword %s empty argument",
            filename, linenum, keyword);
        goto out;
      }
      /* Allow "none" only in first position */
      if (strcasecmp(arg, "none") == 0) {
        if (i > 0 || ac > 0) {
          error("%s line %d: keyword %s \"none\" "
              "argument must appear alone.",
              filename, linenum, keyword);
          goto out;
        }
      }
      i++;
      if (*activep && value) {
        if ((*uintptr) >= max_entries) {
          error("%s line %d: too many %s "
              "entries.", filename, linenum,
              keyword);
          goto out;
        }
        cpptr[(*uintptr)++] = xstrdup(arg);
      }
    }
    break;

  case oUserKnownHostsFile:
    cpptr = (char **)&options->user_hostfiles;
    uintptr = &options->num_user_hostfiles;
    max_entries = SSH_MAX_HOSTS_FILES;
    goto parse_char_array;

  case oHostname:
    charptr = &options->hostname;
    goto parse_string;

  case oTag:
    charptr = &options->tag;
    goto parse_string;

  case oHostKeyAlias:
    charptr = &options->host_key_alias;
    goto parse_string;

  case oPreferredAuthentications:
    charptr = &options->preferred_authentications;
    goto parse_string;

  case oBindAddress:
    charptr = &options->bind_address;
    goto parse_string;

  case oBindInterface:
    charptr = &options->bind_interface;
    goto parse_string;

  case oPKCS11Provider:
    charptr = &options->pkcs11_provider;
    goto parse_string;

  case oSecurityKeyProvider:
    charptr = &options->sk_provider;
    goto parse_string;

  case oKnownHostsCommand:
    charptr = &options->known_hosts_command;
    goto parse_command;

  case oProxyCommand:
    charptr = &options->proxy_command;
parse_command:
    if (str == NULL) {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    len = strspn(str, WHITESPACE "=");
    if (*activep && *charptr == NULL)
      *charptr = xstrdup(str + len);
    argv_consume(&ac);
    break;

  case oProxyJump:
    if (str == NULL) {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    len = strspn(str, WHITESPACE "=");
    /* XXX use argv? */
    if (parse_jump(str + len, options, cmdline, *activep) == -1) {
      error("%.200s line %d: Invalid ProxyJump \"%s\"",
          filename, linenum, str + len);
      goto out;
    }
    argv_consume(&ac);
    break;

  case oPort:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    value = a2port(arg);
    if (value <= 0) {
      error("%.200s line %d: Bad port '%s'.",
          filename, linenum, arg);
      goto out;
    }
    if (*activep && options->port == -1)
      options->port = value;
    break;

  case oConnectionAttempts:
    intptr = &options->connection_attempts;
parse_int:
    arg = argv_next(&ac, &av);
    if ((errstr = atoi_err(arg, &value)) != NULL) {
      error("%s line %d: integer value %s.",
          filename, linenum, errstr);
      goto out;
    }
    if (*activep && *intptr == -1)
      *intptr = value;
    break;

  case oCiphers:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*arg != '-' &&
        !ciphers_valid(*arg == '+' || *arg == '^' ? arg + 1 : arg)){
      error("%.200s line %d: Bad SSH2 cipher spec '%s'.",
          filename, linenum, arg ? arg : "<NONE>");
      goto out;
    }
    if (*activep && options->ciphers == NULL)
      options->ciphers = xstrdup(arg);
    break;

  case oMacs:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*arg != '-' &&
        !mac_valid(*arg == '+' || *arg == '^' ? arg + 1 : arg)) {
      error("%.200s line %d: Bad SSH2 MAC spec '%s'.",
          filename, linenum, arg ? arg : "<NONE>");
      goto out;
    }
    if (*activep && options->macs == NULL)
      options->macs = xstrdup(arg);
    break;

  case oKexAlgorithms:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*arg != '-' &&
        !kex_names_valid(*arg == '+' || *arg == '^' ?
        arg + 1 : arg)) {
      error("%.200s line %d: Bad SSH2 KexAlgorithms '%s'.",
          filename, linenum, arg ? arg : "<NONE>");
      goto out;
    }
    if (*activep && options->kex_algorithms == NULL)
      options->kex_algorithms = xstrdup(arg);
    break;

  case oHostKeyAlgorithms:
    charptr = &options->hostkeyalgorithms;
    ca_only = 0;
parse_pubkey_algos:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*arg != '-' &&
        !sshkey_names_valid2(*arg == '+' || *arg == '^' ?
        arg + 1 : arg, 1, ca_only)) {
      error("%s line %d: Bad key types '%s'.",
          filename, linenum, arg ? arg : "<NONE>");
      goto out;
    }
    if (*activep && *charptr == NULL)
      *charptr = xstrdup(arg);
    break;

  case oCASignatureAlgorithms:
    charptr = &options->ca_sign_algorithms;
    ca_only = 1;
    goto parse_pubkey_algos;

  case oLogLevel:
    log_level_ptr = &options->log_level;
    arg = argv_next(&ac, &av);
    value = log_level_number(arg);
    if (value == SYSLOG_LEVEL_NOT_SET) {
      error("%.200s line %d: unsupported log level '%s'",
          filename, linenum, arg ? arg : "<NONE>");
      goto out;
    }
    if (*activep && *log_level_ptr == SYSLOG_LEVEL_NOT_SET)
      *log_level_ptr = (LogLevel) value;
    break;

  case oLogFacility:
    log_facility_ptr = &options->log_facility;
    arg = argv_next(&ac, &av);
    value = log_facility_number(arg);
    if (value == SYSLOG_FACILITY_NOT_SET) {
      error("%.200s line %d: unsupported log facility '%s'",
          filename, linenum, arg ? arg : "<NONE>");
      goto out;
    }
    if (*log_facility_ptr == -1)
      *log_facility_ptr = (SyslogFacility) value;
    break;

  case oLogVerbose:
    cppptr = &options->log_verbose;
    uintptr = &options->num_log_verbose;
    i = 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (*arg == '\0') {
        error("%s line %d: keyword %s empty argument",
            filename, linenum, keyword);
        goto out;
      }
      /* Allow "none" only in first position */
      if (strcasecmp(arg, "none") == 0) {
        if (i > 0 || ac > 0) {
          error("%s line %d: keyword %s \"none\" "
              "argument must appear alone.",
              filename, linenum, keyword);
          goto out;
        }
      }
      i++;
      if (*activep && *uintptr == 0) {
        *cppptr = xrecallocarray(*cppptr, *uintptr,
            *uintptr + 1, sizeof(**cppptr));
        (*cppptr)[(*uintptr)++] = xstrdup(arg);
      }
    }
    break;

  case oLocalForward:
  case oRemoteForward:
  case oDynamicForward:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }

    remotefwd = (opcode == oRemoteForward);
    dynamicfwd = (opcode == oDynamicForward);

    if (!dynamicfwd) {
      arg2 = argv_next(&ac, &av);
      if (arg2 == NULL || *arg2 == '\0') {
        if (remotefwd)
          dynamicfwd = 1;
        else {
          error("%.200s line %d: Missing target "
              "argument.", filename, linenum);
          goto out;
        }
      } else {
        /* construct a string for parse_forward */
        snprintf(fwdarg, sizeof(fwdarg), "%s:%s", arg,
            arg2);
      }
    }
    if (dynamicfwd)
      strlcpy(fwdarg, arg, sizeof(fwdarg));

    if (parse_forward(&fwd, fwdarg, dynamicfwd, remotefwd) == 0) {
      error("%.200s line %d: Bad forwarding specification.",
          filename, linenum);
      goto out;
    }

    if (*activep) {
      if (remotefwd) {
        add_remote_forward(options, &fwd);
      } else {
        add_local_forward(options, &fwd);
      }
    }
    break;

  case oPermitRemoteOpen:
    uintptr = &options->num_permitted_remote_opens;
    cppptr = &options->permitted_remote_opens;
    found = *uintptr == 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      arg2 = xstrdup(arg);
      /* Allow any/none only in first position */
      if (strcasecmp(arg, "none") == 0 ||
          strcasecmp(arg, "any") == 0) {
        if (nstrs > 0 || ac > 0) {
          error("%s line %d: keyword %s \"%s\" "
              "argument must appear alone.",
              filename, linenum, keyword, arg);
          free(arg2);
          goto out;
        }
      } else {
        p = hpdelim(&arg);
        if (p == NULL) {
          fatal("%s line %d: missing host in %s",
              filename, linenum,
              lookup_opcode_name(opcode));
        }
        p = cleanhostname(p);
        /*
         * don't want to use permitopen_port to avoid
         * dependency on channels.[ch] here.
         */
        if (arg == NULL || (strcmp(arg, "*") != 0 &&
            a2port(arg) <= 0)) {
          fatal("%s line %d: bad port number "
              "in %s", filename, linenum,
              lookup_opcode_name(opcode));
        }
      }
      opt_array_append(filename, linenum,
          lookup_opcode_name(opcode),
          &strs, &nstrs, arg2);
      free(arg2);
    }
    if (nstrs == 0)
      fatal("%s line %d: missing %s specification",
          filename, linenum, lookup_opcode_name(opcode));
    if (found && *activep) {
      *cppptr = strs;
      *uintptr = nstrs;
      strs = NULL; /* transferred */
      nstrs = 0;
    }
    break;

  case oClearAllForwardings:
    intptr = &options->clear_forwardings;
    goto parse_flag;

  case oHost:
    if (cmdline) {
      error("Host directive not supported as a command-line "
          "option");
      goto out;
    }
    *activep = 0;
    arg2 = NULL;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (*arg == '\0') {
        error("%s line %d: keyword %s empty argument",
            filename, linenum, keyword);
        goto out;
      }
      if ((flags & SSHCONF_NEVERMATCH) != 0) {
        argv_consume(&ac);
        break;
      }
      negated = *arg == '!';
      if (negated)
        arg++;
      if (match_pattern(host, arg)) {
        if (negated) {
          debug("%.200s line %d: Skipping Host "
              "block because of negated match "
              "for %.100s", filename, linenum,
              arg);
          *activep = 0;
          argv_consume(&ac);
          break;
        }
        if (!*activep)
          arg2 = arg; /* logged below */
        *activep = 1;
      }
    }
    if (*activep)
      debug("%.200s line %d: Applying options for %.100s",
          filename, linenum, arg2);
    break;

  case oMatch:
    if (cmdline) {
      error("Match directive not supported as a command-line "
          "option");
      goto out;
    }
    value = match_cfg_line(options, str, &ac, &av, pw, host,
        original_host, remote_command, flags & SSHCONF_FINAL,
        want_final_pass, filename, linenum);
    if (value < 0) {
      error("%.200s line %d: Bad Match condition", filename,
          linenum);
      goto out;
    }
    *activep = (flags & SSHCONF_NEVERMATCH) ? 0 : value;
    break;

  case oEscapeChar:
    intptr = &options->escape_char;
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (strcmp(arg, "none") == 0)
      value = SSH_ESCAPECHAR_NONE;
    else if (arg[1] == '\0')
      value = (u_char) arg[0];
    else if (arg[0] == '^' && arg[2] == 0 &&
        (u_char) arg[1] >= 64 && (u_char) arg[1] < 128)
      value = (u_char) arg[1] & 31;
    else {
      error("%.200s line %d: Bad escape character.",
          filename, linenum);
      goto out;
    }
    if (*activep && *intptr == -1)
      *intptr = value;
    break;

  case oAddressFamily:
    intptr = &options->address_family;
    multistate_ptr = multistate_addressfamily;
    goto parse_multistate;

  case oEnableSSHKeysign:
    intptr = &options->enable_ssh_keysign;
    goto parse_flag;

  case oIdentitiesOnly:
    intptr = &options->identities_only;
    goto parse_flag;

  case oServerAliveInterval:
    intptr = &options->server_alive_interval;
    goto parse_time;

  case oServerAliveCountMax:
    intptr = &options->server_alive_count_max;
    goto parse_int;

  case oSendEnv:
    /* XXX appends to list; doesn't respect first-match-wins */
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (*arg == '\0' || strchr(arg, '=') != NULL) {
        error("%s line %d: Invalid environment name.",
            filename, linenum);
        goto out;
      }
      found = 1;
      if (!*activep)
        continue;
      if (*arg == '-') {
        /* Removing an env var */
        rm_env(options, arg, filename, linenum);
        continue;
      }
      opt_array_append(filename, linenum,
          lookup_opcode_name(opcode),
          &options->send_env, &options->num_send_env, arg);
    }
    if (!found) {
      fatal("%s line %d: no %s specified",
          filename, linenum, keyword);
    }
    break;

  case oSetEnv:
    found = options->num_setenv == 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (strchr(arg, '=') == NULL) {
        error("%s line %d: Invalid SetEnv.",
            filename, linenum);
        goto out;
      }
      if (lookup_setenv_in_list(arg, strs, nstrs) != NULL) {
        debug2("%s line %d: ignoring duplicate env "
            "name \"%.64s\"", filename, linenum, arg);
        continue;
      }
      opt_array_append(filename, linenum,
          lookup_opcode_name(opcode),
          &strs, &nstrs, arg);
    }
    if (nstrs == 0) {
      fatal("%s line %d: no %s specified",
          filename, linenum, keyword);
    }
    if (found && *activep) {
      options->setenv = strs;
      options->num_setenv = nstrs;
      strs = NULL; /* transferred */
      nstrs = 0;
    }
    break;

  case oControlPath:
    charptr = &options->control_path;
    goto parse_string;

  case oControlMaster:
    intptr = &options->control_master;
    multistate_ptr = multistate_controlmaster;
    goto parse_multistate;

  case oControlPersist:
    /* no/false/yes/true, or a time spec */
    intptr = &options->control_persist;
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing ControlPersist"
          " argument.", filename, linenum);
      goto out;
    }
    value = 0;
    value2 = 0; /* timeout */
    if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
      value = 0;
    else if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
      value = 1;
    else if ((value2 = convtime(arg)) >= 0)
      value = 1;
    else {
      error("%.200s line %d: Bad ControlPersist argument.",
          filename, linenum);
      goto out;
    }
    if (*activep && *intptr == -1) {
      *intptr = value;
      options->control_persist_timeout = value2;
    }
    break;

  case oHashKnownHosts:
    intptr = &options->hash_known_hosts;
    goto parse_flag;

  case oTunnel:
    intptr = &options->tun_open;
    multistate_ptr = multistate_tunnel;
    goto parse_multistate;

  case oTunnelDevice:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    value = a2tun(arg, &value2);
    if (value == SSH_TUNID_ERR) {
      error("%.200s line %d: Bad tun device.",
          filename, linenum);
      goto out;
    }
    if (*activep && options->tun_local == -1) {
      options->tun_local = value;
      options->tun_remote = value2;
    }
    break;

  case oLocalCommand:
    charptr = &options->local_command;
    goto parse_command;

  case oPermitLocalCommand:
    intptr = &options->permit_local_command;
    goto parse_flag;

  case oRemoteCommand:
    charptr = &options->remote_command;
    goto parse_command;

  case oVisualHostKey:
    intptr = &options->visual_host_key;
    goto parse_flag;

  case oInclude:
    if (cmdline) {
      error("Include directive not supported as a "
          "command-line option");
      goto out;
    }
    value = 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (*arg == '\0') {
        error("%s line %d: keyword %s empty argument",
            filename, linenum, keyword);
        goto out;
      }
      /* Expand %tokens and environment variables */
      if ((p = expand_match_exec_or_include_path(arg,
          options, pw, host, original_host,
          flags & SSHCONF_FINAL, 1)) == NULL) {
        error("%.200s line %d: Unable to expand user "
            "config file '%.100s'",
            filename, linenum, arg);
        continue;
      }
      /*
       * Ensure all paths are anchored. User configuration
       * files may begin with '~/' but system configurations
       * must not. If the path is relative, then treat it
       * as living in ~/.ssh for user configurations or
       * /etc/ssh for system ones.
       */
      if (*p == '~' && (flags & SSHCONF_USERCONF) == 0) {
        error("%.200s line %d: bad include path %s.",
            filename, linenum, p);
        goto out;
      }
      if (!path_absolute(p) && *p != '~') {
        xasprintf(&arg2, "%s/%s",
            (flags & SSHCONF_USERCONF) ?
            "~/" _PATH_SSH_USER_DIR : SSHDIR, p);
      } else {
        arg2 = xstrdup(p);
      }
      free(p);
      memset(&gl, 0, sizeof(gl));
      r = glob(arg2, GLOB_TILDE, NULL, &gl);
      if (r == GLOB_NOMATCH) {
        debug("%.200s line %d: include %s matched no "
            "files",filename, linenum, arg2);
        free(arg2);
        continue;
      } else if (r != 0) {
        error("%.200s line %d: glob failed for %s.",
            filename, linenum, arg2);
        goto out;
      }
      free(arg2);
      oactive = *activep;
      for (i = 0; i < gl.gl_pathc; i++) {
        debug3("%.200s line %d: Including file %s "
            "depth %d%s", filename, linenum,
            gl.gl_pathv[i], depth,
            oactive ? "" : " (parse only)");
        r = read_config_file_depth(gl.gl_pathv[i],
            pw, host, original_host, remote_command,
            options, flags | SSHCONF_CHECKPERM |
            (oactive ? 0 : SSHCONF_NEVERMATCH),
            activep, want_final_pass, depth + 1);
        if (r != 1 && errno != ENOENT) {
          error("%.200s line %d: Can't open user "
              "config file %.100s: %.100s",
              filename, linenum, gl.gl_pathv[i],
              strerror(errno));
          globfree(&gl);
          goto out;
        }
        /*
         * don't let Match in includes clobber the
         * containing file's Match state.
         */
        *activep = oactive;
        if (r != 1)
          value = -1;
      }
      globfree(&gl);
    }
    if (value != 0)
      ret = value;
    break;

  case oIPQoS:
    arg = argv_next(&ac, &av);
    if ((value = parse_ipqos(arg)) == -1) {
      error("%s line %d: Bad IPQoS value: %s",
          filename, linenum, arg);
      goto out;
    }
    if (value == INT_MIN) {
      debug("%s line %d: Deprecated IPQoS value \"%s\" "
          "ignored - using system default instead. Consider"
          " using DSCP values.", filename, linenum, arg);
      value = INT_MAX;
    }
    arg = argv_next(&ac, &av);
    if (arg == NULL)
      value2 = value;
    else if ((value2 = parse_ipqos(arg)) == -1) {
      error("%s line %d: Bad IPQoS value: %s",
          filename, linenum, arg);
      goto out;
    }
    if (value2 == INT_MIN) {
      debug("%s line %d: Deprecated IPQoS value \"%s\" "
          "ignored - using system default instead. Consider"
          " using DSCP values.", filename, linenum, arg);
      value2 = INT_MAX;
    }
    if (*activep && options->ip_qos_interactive == -1) {
      options->ip_qos_interactive = value;
      options->ip_qos_bulk = value2;
    }
    break;

  case oRequestTTY:
    intptr = &options->request_tty;
    multistate_ptr = multistate_requesttty;
    goto parse_multistate;

  case oSessionType:
    intptr = &options->session_type;
    multistate_ptr = multistate_sessiontype;
    goto parse_multistate;

  case oStdinNull:
    intptr = &options->stdin_null;
    goto parse_flag;

  case oForkAfterAuthentication:
    intptr = &options->fork_after_authentication;
    goto parse_flag;

  case oIgnoreUnknown:
    charptr = &options->ignored_unknown;
    goto parse_string;

  case oProxyUseFdpass:
    intptr = &options->proxy_use_fdpass;
    goto parse_flag;

  case oCanonicalDomains:
    found = options->num_canonical_domains == 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      /* Allow "none" only in first position */
      if (strcasecmp(arg, "none") == 0) {
        if (nstrs > 0 || ac > 0) {
          error("%s line %d: keyword %s \"none\" "
              "argument must appear alone.",
              filename, linenum, keyword);
          goto out;
        }
      }
      if (!valid_domain(arg, 1, &errstr)) {
        error("%s line %d: %s", filename, linenum,
            errstr);
        goto out;
      }
      opt_array_append(filename, linenum, keyword,
          &strs, &nstrs, arg);
    }
    if (nstrs == 0) {
      fatal("%s line %d: no %s specified",
          filename, linenum, keyword);
    }
    if (found && *activep) {
      options->canonical_domains = strs;
      options->num_canonical_domains = nstrs;
      strs = NULL; /* transferred */
      nstrs = 0;
    }
    break;

  case oCanonicalizePermittedCNAMEs:
    found = options->num_permitted_cnames == 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      /*
       * Either 'none' (only in first position), '*' for
       * everything or 'list:list'
       */
      if (strcasecmp(arg, "none") == 0) {
        if (ncnames > 0 || ac > 0) {
          error("%s line %d: keyword %s \"none\" "
              "argument must appear alone.",
              filename, linenum, keyword);
          goto out;
        }
        arg2 = "";
      } else if (strcmp(arg, "*") == 0) {
        arg2 = arg;
      } else {
        lowercase(arg);
        if ((arg2 = strchr(arg, ':')) == NULL ||
            arg2[1] == '\0') {
          error("%s line %d: "
              "Invalid permitted CNAME \"%s\"",
              filename, linenum, arg);
          goto out;
        }
        *arg2 = '\0';
        arg2++;
      }
      cnames = xrecallocarray(cnames, ncnames, ncnames + 1,
          sizeof(*cnames));
      cnames[ncnames].source_list = xstrdup(arg);
      cnames[ncnames].target_list = xstrdup(arg2);
      ncnames++;
    }
    if (ncnames == 0) {
      fatal("%s line %d: no %s specified",
          filename, linenum, keyword);
    }
    if (found && *activep) {
      options->permitted_cnames = cnames;
      options->num_permitted_cnames = ncnames;
      cnames = NULL; /* transferred */
      ncnames = 0;
    }
    /* un-transferred cnames is cleaned up before exit */
    break;

  case oCanonicalizeHostname:
    intptr = &options->canonicalize_hostname;
    multistate_ptr = multistate_canonicalizehostname;
    goto parse_multistate;

  case oCanonicalizeMaxDots:
    intptr = &options->canonicalize_max_dots;
    goto parse_int;

  case oCanonicalizeFallbackLocal:
    intptr = &options->canonicalize_fallback_local;
    goto parse_flag;

  case oStreamLocalBindMask:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing StreamLocalBindMask "
          "argument.", filename, linenum);
      goto out;
    }
    /* Parse mode in octal format */
    value = strtol(arg, &endofnumber, 8);
    if (arg == endofnumber || value < 0 || value > 0777) {
      error("%.200s line %d: Bad mask.", filename, linenum);
      goto out;
    }
    if (*activep &&
        options->fwd_opts.streamlocal_bind_mask == (mode_t)-1)
      options->fwd_opts.streamlocal_bind_mask = (mode_t)value;
    break;

  case oStreamLocalBindUnlink:
    intptr = &options->fwd_opts.streamlocal_bind_unlink;
    goto parse_flag;

  case oRevokedHostKeys:
    uintptr = &options->num_revoked_host_keys;
    cppptr = &options->revoked_host_keys;
    found = *uintptr == 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (*arg == '\0') {
        error("%s line %d: keyword %s empty argument",
            filename, linenum, keyword);
        goto out;
      }
      /* Allow "none" only in first position */
      if (strcasecmp(arg, "none") == 0) {
        if (nstrs > 0 || ac > 0) {
          error("%s line %d: keyword %s \"none\" "
              "argument must appear alone.",
              filename, linenum, keyword);
          goto out;
        }
      }
      opt_array_append(filename, linenum, keyword,
          &strs, &nstrs, arg);
    }
    if (nstrs == 0) {
      fatal("%s line %d: no %s specified",
          filename, linenum, keyword);
    }
    if (found && *activep) {
      *cppptr = strs;
      *uintptr = nstrs;
      strs = NULL; /* transferred */
      nstrs = 0;
    }
    break;

  case oFingerprintHash:
    intptr = &options->fingerprint_hash;
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if ((value = ssh_digest_alg_by_name(arg)) == -1) {
      error("%.200s line %d: Invalid hash algorithm \"%s\".",
          filename, linenum, arg);
      goto out;
    }
    if (*activep && *intptr == -1)
      *intptr = value;
    break;

  case oUpdateHostkeys:
    intptr = &options->update_hostkeys;
    multistate_ptr = multistate_yesnoask;
    goto parse_multistate;

  case oHostbasedAcceptedAlgorithms:
    charptr = &options->hostbased_accepted_algos;
    ca_only = 0;
    goto parse_pubkey_algos;

  case oPubkeyAcceptedAlgorithms:
    charptr = &options->pubkey_accepted_algos;
    ca_only = 0;
    goto parse_pubkey_algos;

  case oAddKeysToAgent:
    arg = argv_next(&ac, &av);
    arg2 = argv_next(&ac, &av);
    value = parse_multistate_value(arg, filename, linenum,
        multistate_yesnoaskconfirm);
    value2 = 0; /* unlimited lifespan by default */
    if (value == 3 && arg2 != NULL) {
      /* allow "AddKeysToAgent confirm 5m" */
      if ((value2 = convtime(arg2)) == -1) {
        error("%s line %d: invalid time value.",
            filename, linenum);
        goto out;
      }
    } else if (value == -1 && arg2 == NULL) {
      if ((value2 = convtime(arg)) == -1) {
        error("%s line %d: unsupported option",
            filename, linenum);
        goto out;
      }
      value = 1; /* yes */
    } else if (value == -1 || arg2 != NULL) {
      error("%s line %d: unsupported option",
          filename, linenum);
      goto out;
    }
    if (*activep && options->add_keys_to_agent == -1) {
      options->add_keys_to_agent = value;
      options->add_keys_to_agent_lifespan = value2;
    }
    break;

  case oIdentityAgent:
    charptr = &options->identity_agent;
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
  parse_agent_path:
    /* Extra validation if the string represents an env var. */
    if ((arg2 = dollar_expand(&r, arg)) == NULL || r) {
      error("%.200s line %d: Invalid environment expansion "
          "%s.", filename, linenum, arg);
      goto out;
    }
    free(arg2);
    /* check for legacy environment format */
    if (arg[0] == '$' && arg[1] != '{' &&
        !valid_env_name(arg + 1)) {
      error("%.200s line %d: Invalid environment name %s.",
          filename, linenum, arg);
      goto out;
    }
    if (*activep && *charptr == NULL)
      *charptr = xstrdup(arg);
    break;

  case oEnableEscapeCommandline:
    intptr = &options->enable_escape_commandline;
    goto parse_flag;

  case oRequiredRSASize:
    intptr = &options->required_rsa_size;
    goto parse_int;

  case oWarnWeakCrypto:
    intptr = &options->warn_weak_crypto;
    multistate_ptr = multistate_warnweakcrypto;
    goto parse_multistate;

  case oObscureKeystrokeTiming:
    value = -1;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      if (value != -1) {
        error("%s line %d: invalid arguments",
            filename, linenum);
        goto out;
      }
      if (strcmp(arg, "yes") == 0 ||
          strcmp(arg, "true") == 0)
        value = SSH_KEYSTROKE_DEFAULT_INTERVAL_MS;
      else if (strcmp(arg, "no") == 0 ||
          strcmp(arg, "false") == 0)
        value = 0;
      else if (strncmp(arg, "interval:", 9) == 0) {
        if ((errstr = atoi_err(arg + 9,
            &value)) != NULL) {
          error("%s line %d: integer value %s.",
              filename, linenum, errstr);
          goto out;
        }
        if (value <= 0 || value > 1000) {
          error("%s line %d: value out of range.",
              filename, linenum);
          goto out;
        }
      } else {
        error("%s line %d: unsupported argument \"%s\"",
            filename, linenum, arg);
        goto out;
      }
    }
    if (value == -1) {
      error("%s line %d: missing argument",
          filename, linenum);
      goto out;
    }
    intptr = &options->obscure_keystroke_timing_interval;
    if (*activep && *intptr == -1)
      *intptr = value;
    break;

  case oChannelTimeout:
    found = options->num_channel_timeouts == 0;
    while ((arg = argv_next(&ac, &av)) != NULL) {
      /* Allow "none" only in first position */
      if (strcasecmp(arg, "none") == 0) {
        if (nstrs > 0 || ac > 0) {
          error("%s line %d: keyword %s \"none\" "
              "argument must appear alone.",
              filename, linenum, keyword);
          goto out;
        }
      } else if (parse_pattern_interval(arg,
          NULL, NULL) != 0) {
        fatal("%s line %d: invalid channel timeout %s",
            filename, linenum, arg);
      }
      opt_array_append(filename, linenum, keyword,
          &strs, &nstrs, arg);
    }
    if (nstrs == 0) {
      fatal("%s line %d: no %s specified",
          filename, linenum, keyword);
    }
    if (found && *activep) {
      options->channel_timeouts = strs;
      options->num_channel_timeouts = nstrs;
      strs = NULL; /* transferred */
      nstrs = 0;
    }
    break;

  case oVersionAddendum:
    if (str == NULL || *str == '\0')
      fatal("%s line %d: %s missing argument.",
          filename, linenum, keyword);
    len = strspn(str, WHITESPACE);
    if (strchr(str + len, '\r') != NULL) {
      fatal("%.200s line %d: Invalid %s argument",
          filename, linenum, keyword);
    }
    if ((arg = strchr(line, '#')) != NULL) {
      *arg = '\0';
      rtrim(line);
    }
    if (*activep && options->version_addendum == NULL) {
      if (strcasecmp(str + len, "none") == 0)
        options->version_addendum = xstrdup("");
      else
        options->version_addendum = xstrdup(str + len);
    }
    argv_consume(&ac);
    break;

  case oRefuseConnection:
    arg = argv_next(&ac, &av);
    if (!arg || *arg == '\0') {
      error("%.200s line %d: Missing argument.",
          filename, linenum);
      goto out;
    }
    if (*activep) {
      fatal("%.200s line %d: RefuseConnection: %s",
          filename, linenum, arg);
    }
    break;

  case oDeprecated:
    debug("%s line %d: Deprecated option \"%s\"",
        filename, linenum, keyword);
    argv_consume(&ac);
    break;

  case oUnsupported:
    error("%s line %d: Unsupported option \"%s\"",
        filename, linenum, keyword);
    argv_consume(&ac);
    break;

  default:
    error("%s line %d: Unimplemented opcode %d",
        filename, linenum, opcode);
    goto out;
  }

  /* Check that there is no garbage at end of line. */
  if (ac > 0) {
    error("%.200s line %d: keyword %s extra arguments "
        "at end of line", filename, linenum, keyword);
    goto out;
  }

  /* success */
  ret = 0;
 out:
  free_canon_cnames(cnames, ncnames);
  opt_array_free2(strs, NULL, nstrs);
  argv_free(oav, oac);
  return ret;
}

/*
 * Reads the config file and modifies the options accordingly.  Options
 * should already be initialized before this call.  This never returns if
 * there is an error.  If the file does not exist, this returns 0.
 */
int
read_config_file(const char *filename, struct passwd *pw, const char *host,
    const char *original_host, const char *remote_command, Options *options, int flags,
    int *want_final_pass)
{
  int active = 1;

  return read_config_file_depth(filename, pw, host, original_host,
      remote_command, options, flags, &active, want_final_pass, 0);
}

#define READCONF_MAX_DEPTH  16
static int
read_config_file_depth(const char *filename, struct passwd *pw,
    const char *host, const char *original_host, const char *remote_command,
    Options *options, int flags, int *activep, int *want_final_pass, int depth)
{
  FILE *f;
  char *line = NULL;
  size_t linesize = 0;
  int linenum;
  int bad_options = 0;

  if (depth < 0 || depth > READCONF_MAX_DEPTH)
    fatal("Too many recursive configuration includes");

  if ((f = fopen(filename, "r")) == NULL)
    return 0;

  if (flags & SSHCONF_CHECKPERM) {
    struct stat sb;

    if (fstat(fileno(f), &sb) == -1)
      fatal("fstat %s: %s", filename, strerror(errno));
    if (((sb.st_uid != 0 && sb.st_uid != getuid()) ||
        (sb.st_mode & 022) != 0))
      fatal("Bad owner or permissions on %s", filename);
  }

  debug("Reading configuration data %.200s", filename);

  /*
   * Mark that we are now processing the options.  This flag is turned
   * on/off by Host specifications.
   */
  linenum = 0;
  while (getline(&line, &linesize, f) != -1) {
    /* Update line number counter. */
    linenum++;
    /*
     * Trim out comments and strip whitespace.
     * NB - preserve newlines, they are needed to reproduce
     * line numbers later for error messages.
     */
    if (process_config_line_depth(options, pw, host, original_host,
        remote_command, line, filename, linenum, activep, flags,
        want_final_pass, depth) != 0)
      bad_options++;
  }
  free(line);
  fclose(f);
  if (bad_options > 0)
    fatal("%s: terminating, %d bad configuration options",
        filename, bad_options);
  return 1;
}

/* Returns 1 if a string option is unset or set to "none" or 0 otherwise. */
int
option_clear_or_none(const char *o)
{
  return o == NULL || strcasecmp(o, "none") == 0;
}

/*
 * Returns 1 if CanonicalizePermittedCNAMEs have been specified, 0 otherwise.
 * Allowed to be called on non-final configuration.
 */
int
config_has_permitted_cnames(Options *options)
{
  if (options->num_permitted_cnames == 1 &&
      strcasecmp(options->permitted_cnames[0].source_list, "none") == 0 &&
      strcmp(options->permitted_cnames[0].target_list, "") == 0)
    return 0;
  return options->num_permitted_cnames > 0;
}

/*
 * Initializes options to special values that indicate that they have not yet
 * been set.  Read_config_file will only set options with this value. Options
 * are processed in the following order: command line, user config file,
 * system config file.  Last, fill_default_options is called.
 */

void
initialize_options(Options * options)
{
  memset(options, 'X', sizeof(*options));
  options->host_arg = NULL;
  options->forward_agent = -1;
  options->forward_agent_sock_path = NULL;
  options->forward_x11 = -1;
  options->forward_x11_trusted = -1;
  options->forward_x11_timeout = -1;
  options->stdio_forward_host = NULL;
  options->stdio_forward_port = 0;
  options->clear_forwardings = -1;
  options->exit_on_forward_failure = -1;
  options->xauth_location = NULL;
  options->fwd_opts.gateway_ports = -1;
  options->fwd_opts.streamlocal_bind_mask = (mode_t)-1;
  options->fwd_opts.streamlocal_bind_unlink = -1;
  options->pubkey_authentication = -1;
  options->gss_authentication = -1;
  options->gss_deleg_creds = -1;
  options->password_authentication = -1;
  options->kbd_interactive_authentication = -1;
  options->kbd_interactive_devices = NULL;
  options->hostbased_authentication = -1;
  options->batch_mode = -1;
  options->check_host_ip = -1;
  options->strict_host_key_checking = -1;
  options->compression = -1;
  options->tcp_keep_alive = -1;
  options->port = -1;
  options->address_family = -1;
  options->connection_attempts = -1;
  options->connection_timeout = -1;
  options->number_of_password_prompts = -1;
  options->ciphers = NULL;
  options->macs = NULL;
  options->kex_algorithms = NULL;
  options->hostkeyalgorithms = NULL;
  options->ca_sign_algorithms = NULL;
  options->num_identity_files = 0;
  memset(options->identity_keys, 0, sizeof(options->identity_keys));
  options->num_certificate_files = 0;
  memset(options->certificates, 0, sizeof(options->certificates));
  options->hostname = NULL;
  options->host_key_alias = NULL;
  options->proxy_command = NULL;
  options->jump_user = NULL;
  options->jump_host = NULL;
  options->jump_port = -1;
  options->jump_extra = NULL;
  options->user = NULL;
  options->escape_char = -1;
  options->num_system_hostfiles = 0;
  options->num_user_hostfiles = 0;
  options->local_forwards = NULL;
  options->num_local_forwards = 0;
  options->remote_forwards = NULL;
  options->num_remote_forwards = 0;
  options->permitted_remote_opens = NULL;
  options->num_permitted_remote_opens = 0;
  options->log_facility = SYSLOG_FACILITY_NOT_SET;
  options->log_level = SYSLOG_LEVEL_NOT_SET;
  options->num_log_verbose = 0;
  options->log_verbose = NULL;
  options->preferred_authentications = NULL;
  options->bind_address = NULL;
  options->bind_interface = NULL;
  options->pkcs11_provider = NULL;
  options->sk_provider = NULL;
  options->enable_ssh_keysign = -1;
  options->no_host_authentication_for_localhost = -1;
  options->identities_only = -1;
  options->rekey_limit = -1;
  options->rekey_interval = -1;
  options->verify_host_key_dns = -1;
  options->server_alive_interval = -1;
  options->server_alive_count_max = -1;
  options->send_env = NULL;
  options->num_send_env = 0;
  options->setenv = NULL;
  options->num_setenv = 0;
  options->control_path = NULL;
  options->control_master = -1;
  options->control_persist = -1;
  options->control_persist_timeout = 0;
  options->hash_known_hosts = -1;
  options->tun_open = -1;
  options->tun_local = -1;
  options->tun_remote = -1;
  options->local_command = NULL;
  options->permit_local_command = -1;
  options->remote_command = NULL;
  options->add_keys_to_agent = -1;
  options->add_keys_to_agent_lifespan = -1;
  options->identity_agent = NULL;
  options->visual_host_key = -1;
  options->ip_qos_interactive = -1;
  options->ip_qos_bulk = -1;
  options->request_tty = -1;
  options->session_type = -1;
  options->stdin_null = -1;
  options->fork_after_authentication = -1;
  options->proxy_use_fdpass = -1;
  options->ignored_unknown = NULL;
  options->num_canonical_domains = 0;
  options->num_permitted_cnames = 0;
  options->canonicalize_max_dots = -1;
  options->canonicalize_fallback_local = -1;
  options->canonicalize_hostname = -1;
  options->revoked_host_keys = NULL;
  options->num_revoked_host_keys = 0;
  options->fingerprint_hash = -1;
  options->update_hostkeys = -1;
  options->hostbased_accepted_algos = NULL;
  options->pubkey_accepted_algos = NULL;
  options->known_hosts_command = NULL;
  options->required_rsa_size = -1;
  options->warn_weak_crypto = -1;
  options->enable_escape_commandline = -1;
  options->obscure_keystroke_timing_interval = -1;
  options->tag = NULL;
  options->channel_timeouts = NULL;
  options->num_channel_timeouts = 0;
  options->version_addendum = NULL;
}

/*
 * A petite version of fill_default_options() that just fills the options
 * needed for hostname canonicalization to proceed.
 */
void
fill_default_options_for_canonicalization(Options *options)
{
  if (options->canonicalize_max_dots == -1)
    options->canonicalize_max_dots = 1;
  if (options->canonicalize_fallback_local == -1)
    options->canonicalize_fallback_local = 1;
  if (options->canonicalize_hostname == -1)
    options->canonicalize_hostname = SSH_CANONICALISE_NO;
}

/*
 * Called after processing other sources of option data, this fills those
 * options for which no value has been specified with their default values.
 */
int
fill_default_options(Options * options)
{
  char *all_cipher, *all_mac, *all_kex, *all_key, *all_sig;
  char *def_cipher, *def_mac, *def_kex, *def_key, *def_sig;
  int ret = -1, r;

  if (options->forward_agent == -1)
    options->forward_agent = 0;
  if (options->forward_x11 == -1)
    options->forward_x11 = 0;
  if (options->forward_x11_trusted == -1)
    options->forward_x11_trusted = 0;
  if (options->forward_x11_timeout == -1)
    options->forward_x11_timeout = 1200;
  /*
   * stdio forwarding (-W) changes the default for these but we defer
   * setting the values so they can be overridden.
   */
  if (options->exit_on_forward_failure == -1)
    options->exit_on_forward_failure =
        options->stdio_forward_host != NULL ? 1 : 0;
  if (options->clear_forwardings == -1)
    options->clear_forwardings =
        options->stdio_forward_host != NULL ? 1 : 0;
  if (options->clear_forwardings == 1)
    clear_forwardings(options);

  if (options->xauth_location == NULL)
    options->xauth_location = xstrdup(_PATH_XAUTH);
  if (options->fwd_opts.gateway_ports == -1)
    options->fwd_opts.gateway_ports = 0;
  if (options->fwd_opts.streamlocal_bind_mask == (mode_t)-1)
    options->fwd_opts.streamlocal_bind_mask = 0177;
  if (options->fwd_opts.streamlocal_bind_unlink == -1)
    options->fwd_opts.streamlocal_bind_unlink = 0;
  if (options->pubkey_authentication == -1)
    options->pubkey_authentication = SSH_PUBKEY_AUTH_ALL;
  if (options->gss_authentication == -1)
    options->gss_authentication = 0;
  if (options->gss_deleg_creds == -1)
    options->gss_deleg_creds = 0;
  if (options->password_authentication == -1)
    options->password_authentication = 1;
  if (options->kbd_interactive_authentication == -1)
    options->kbd_interactive_authentication = 1;
  if (options->hostbased_authentication == -1)
    options->hostbased_authentication = 0;
  if (options->batch_mode == -1)
    options->batch_mode = 0;
  if (options->check_host_ip == -1)
    options->check_host_ip = 0;
  if (options->strict_host_key_checking == -1)
    options->strict_host_key_checking = SSH_STRICT_HOSTKEY_ASK;
  if (options->compression == -1)
    options->compression = 0;
  if (options->tcp_keep_alive == -1)
    options->tcp_keep_alive = SSH_KEEPALIVES_TRANSPORT;
  if (options->port == -1)
    options->port = 0; /* Filled in ssh_connect. */
  if (options->address_family == -1)
    options->address_family = AF_UNSPEC;
  if (options->connection_attempts == -1)
    options->connection_attempts = 1;
  if (options->number_of_password_prompts == -1)
    options->number_of_password_prompts = 3;
  /* options->hostkeyalgorithms, default set in myproposals.h */
  if (options->add_keys_to_agent == -1) {
    options->add_keys_to_agent = 0;
    options->add_keys_to_agent_lifespan = 0;
  }
  if (options->num_identity_files == 0) {
    add_identity_file(options, "~/", _PATH_SSH_CLIENT_ID_RSA, 0);
    add_identity_file(options, "~/", _PATH_SSH_CLIENT_ID_ECDSA, 0);
    add_identity_file(options, "~/",
        _PATH_SSH_CLIENT_ID_ECDSA_SK, 0);
    add_identity_file(options, "~/",
        _PATH_SSH_CLIENT_ID_ED25519, 0);
    add_identity_file(options, "~/",
        _PATH_SSH_CLIENT_ID_ED25519_SK, 0);
    add_identity_file(options, "~/",
        _PATH_SSH_CLIENT_ID_MLDSA44_ED25519, 0);
  }
  if (options->escape_char == -1)
    options->escape_char = '~';
  if (options->num_system_hostfiles == 0) {
    options->system_hostfiles[options->num_system_hostfiles++] =
        xstrdup(_PATH_SSH_SYSTEM_HOSTFILE);
    options->system_hostfiles[options->num_system_hostfiles++] =
        xstrdup(_PATH_SSH_SYSTEM_HOSTFILE2);
  }
  if (options->update_hostkeys == -1) {
    if (options->verify_host_key_dns <= 0 &&
        (options->num_user_hostfiles == 0 ||
        (options->num_user_hostfiles == 1 && strcmp(options->
        user_hostfiles[0], _PATH_SSH_USER_HOSTFILE) == 0)))
      options->update_hostkeys = SSH_UPDATE_HOSTKEYS_YES;
    else
      options->update_hostkeys = SSH_UPDATE_HOSTKEYS_NO;
  }
  if (options->num_user_hostfiles == 0) {
    options->user_hostfiles[options->num_user_hostfiles++] =
        xstrdup(_PATH_SSH_USER_HOSTFILE);
    options->user_hostfiles[options->num_user_hostfiles++] =
        xstrdup(_PATH_SSH_USER_HOSTFILE2);
  }
  if (options->log_level == SYSLOG_LEVEL_NOT_SET)
    options->log_level = SYSLOG_LEVEL_INFO;
  if (options->log_facility == SYSLOG_FACILITY_NOT_SET)
    options->log_facility = SYSLOG_FACILITY_USER;
  if (options->no_host_authentication_for_localhost == -1)
    options->no_host_authentication_for_localhost = 0;
  if (options->identities_only == -1)
    options->identities_only = 0;
  if (options->enable_ssh_keysign == -1)
    options->enable_ssh_keysign = 0;
  if (options->rekey_limit == -1)
    options->rekey_limit = 0;
  if (options->rekey_interval == -1)
    options->rekey_interval = 0;
  if (options->verify_host_key_dns == -1)
    options->verify_host_key_dns = 0;
  if (options->server_alive_interval == -1)
    options->server_alive_interval = 0;
  if (options->server_alive_count_max == -1)
    options->server_alive_count_max = 3;
  if (options->control_master == -1)
    options->control_master = 0;
  if (options->control_persist == -1) {
    options->control_persist = 0;
    options->control_persist_timeout = 0;
  }
  if (options->hash_known_hosts == -1)
    options->hash_known_hosts = 0;
  if (options->tun_open == -1)
    options->tun_open = SSH_TUNMODE_NO;
  if (options->tun_local == -1)
    options->tun_local = SSH_TUNID_ANY;
  if (options->tun_remote == -1)
    options->tun_remote = SSH_TUNID_ANY;
  if (options->permit_local_command == -1)
    options->permit_local_command = 0;
  if (options->visual_host_key == -1)
    options->visual_host_key = 0;
  if (options->ip_qos_interactive == -1)
    options->ip_qos_interactive = IPTOS_DSCP_EF;
  if (options->ip_qos_bulk == -1)
    options->ip_qos_bulk = IPTOS_DSCP_CS0;
  if (options->request_tty == -1)
    options->request_tty = REQUEST_TTY_AUTO;
  if (options->session_type == -1)
    options->session_type = SESSION_TYPE_DEFAULT;
  if (options->stdin_null == -1)
    options->stdin_null = 0;
  if (options->fork_after_authentication == -1)
    options->fork_after_authentication = 0;
  if (options->proxy_use_fdpass == -1)
    options->proxy_use_fdpass = 0;
  if (options->canonicalize_max_dots == -1)
    options->canonicalize_max_dots = 1;
  if (options->canonicalize_fallback_local == -1)
    options->canonicalize_fallback_local = 1;
  if (options->canonicalize_hostname == -1)
    options->canonicalize_hostname = SSH_CANONICALISE_NO;
  if (options->fingerprint_hash == -1)
    options->fingerprint_hash = SSH_FP_HASH_DEFAULT;
#ifdef ENABLE_SK_INTERNAL
  if (options->sk_provider == NULL)
    options->sk_provider = xstrdup("internal");
#else
  if (options->sk_provider == NULL)
    options->sk_provider = xstrdup("$SSH_SK_PROVIDER");
#endif
  if (options->required_rsa_size == -1)
    options->required_rsa_size = SSH_RSA_MINIMUM_MODULUS_SIZE;
  if (options->warn_weak_crypto == -1)
    options->warn_weak_crypto = 1;
  if (options->enable_escape_commandline == -1)
    options->enable_escape_commandline = 0;
  if (options->obscure_keystroke_timing_interval == -1) {
    options->obscure_keystroke_timing_interval =
        SSH_KEYSTROKE_DEFAULT_INTERVAL_MS;
  }

  /* Expand KEX name lists */
  all_cipher = cipher_alg_list(',', 0);
  all_mac = mac_alg_list(',');
  all_kex = kex_alg_list(',');
  all_key = sshkey_alg_list(0, 0, 1, ',');
  all_sig = sshkey_alg_list(0, 1, 1, ',');
  /* remove unsupported algos from default lists */
  def_cipher = match_filter_allowlist(KEX_CLIENT_ENCRYPT, all_cipher);
  def_mac = match_filter_allowlist(KEX_CLIENT_MAC, all_mac);
  def_kex = match_filter_allowlist(KEX_CLIENT_KEX, all_kex);
  def_key = match_filter_allowlist(KEX_DEFAULT_PK_ALG, all_key);
  def_sig = match_filter_allowlist(SSH_ALLOWED_CA_SIGALGS, all_sig);
#define ASSEMBLE(what, defaults, all) \
  do { \
    if ((r = kex_assemble_names(&options->what, \
        defaults, all)) != 0) { \
      error_fr(r, "%s", #what); \
      goto fail; \
    } \
  } while (0)
  options->kex_algorithms_set = options->kex_algorithms != NULL;
  ASSEMBLE(ciphers, def_cipher, all_cipher);
  ASSEMBLE(macs, def_mac, all_mac);
  ASSEMBLE(kex_algorithms, def_kex, all_kex);
  ASSEMBLE(hostbased_accepted_algos, def_key, all_key);
  ASSEMBLE(pubkey_accepted_algos, def_key, all_key);
  ASSEMBLE(ca_sign_algorithms, def_sig, all_sig);
#undef ASSEMBLE

#define CLEAR_ON_NONE(v) \
  do { \
    if (option_clear_or_none(v)) { \
      free(v); \
      v = NULL; \
    } \
  } while(0)
#define CLEAR_ON_NONE_ARRAY(v, nv, none) \
  do { \
    if (options->nv == 1 && \
        strcasecmp(options->v[0], none) == 0) { \
      free(options->v[0]); \
      free(options->v); \
      options->v = NULL; \
      options->nv = 0; \
    } \
  } while (0)
  CLEAR_ON_NONE(options->local_command);
  CLEAR_ON_NONE(options->remote_command);
  CLEAR_ON_NONE(options->proxy_command);
  CLEAR_ON_NONE(options->control_path);
  CLEAR_ON_NONE(options->pkcs11_provider);
  CLEAR_ON_NONE(options->sk_provider);
  CLEAR_ON_NONE(options->known_hosts_command);
  CLEAR_ON_NONE_ARRAY(channel_timeouts, num_channel_timeouts, "none");
  CLEAR_ON_NONE_ARRAY(revoked_host_keys, num_revoked_host_keys, "none");
#undef CLEAR_ON_NONE
#undef CLEAR_ON_NONE_ARRAY
  if (options->jump_host != NULL &&
      strcmp(options->jump_host, "none") == 0 &&
      options->jump_port == 0 && options->jump_user == NULL) {
    free(options->jump_host);
    options->jump_host = NULL;
  }
  if (options->num_permitted_cnames == 1 &&
      !config_has_permitted_cnames(options)) {
    /* clean up CanonicalizePermittedCNAMEs=none */
    free(options->permitted_cnames[0].source_list);
    free(options->permitted_cnames[0].target_list);
    memset(options->permitted_cnames, '\0',
        sizeof(*options->permitted_cnames));
    options->num_permitted_cnames = 0;
  }
  /* options->identity_agent distinguishes NULL from 'none' */
  /* options->user will be set in the main program if appropriate */
  /* options->hostname will be set in the main program if appropriate */
  /* options->host_key_alias should not be set by default */
  /* options->preferred_authentications will be set in ssh */

  /* success */
  ret = 0;
 fail:
  free(all_cipher);
  free(all_mac);
  free(all_kex);
  free(all_key);
  free(all_sig);
  free(def_cipher);
  free(def_mac);
  free(def_kex);
  free(def_key);
  free(def_sig);
  return ret;
}

void
free_options(Options *o)
{
  int i;

  if (o == NULL)
    return;

#define FREE_ARRAY(type, n, a) \
  do { \
    type _i; \
    for (_i = 0; _i < (n); _i++) \
      free((a)[_i]); \
  } while (0)

  free(o->forward_agent_sock_path);
  free(o->xauth_location);
  FREE_ARRAY(u_int, o->num_log_verbose, o->log_verbose);
  free(o->log_verbose);
  free(o->ciphers);
  free(o->macs);
  free(o->hostkeyalgorithms);
  free(o->kex_algorithms);
  free(o->ca_sign_algorithms);
  free(o->hostname);
  free(o->host_key_alias);
  free(o->proxy_command);
  free(o->user);
  FREE_ARRAY(u_int, o->num_system_hostfiles, o->system_hostfiles);
  FREE_ARRAY(u_int, o->num_user_hostfiles, o->user_hostfiles);
  free(o->preferred_authentications);
  free(o->bind_address);
  free(o->bind_interface);
  free(o->pkcs11_provider);
  free(o->sk_provider);
  for (i = 0; i < o->num_identity_files; i++) {
    free(o->identity_files[i]);
    sshkey_free(o->identity_keys[i]);
  }
  for (i = 0; i < o->num_certificate_files; i++) {
    free(o->certificate_files[i]);
    sshkey_free(o->certificates[i]);
  }
  free(o->identity_agent);
  for (i = 0; i < o->num_local_forwards; i++) {
    free(o->local_forwards[i].listen_host);
    free(o->local_forwards[i].listen_path);
    free(o->local_forwards[i].connect_host);
    free(o->local_forwards[i].connect_path);
  }
  free(o->local_forwards);
  for (i = 0; i < o->num_remote_forwards; i++) {
    free(o->remote_forwards[i].listen_host);
    free(o->remote_forwards[i].listen_path);
    free(o->remote_forwards[i].connect_host);
    free(o->remote_forwards[i].connect_path);
  }
  free(o->remote_forwards);
  free(o->stdio_forward_host);
  FREE_ARRAY(u_int, o->num_send_env, o->send_env);
  free(o->send_env);
  FREE_ARRAY(u_int, o->num_setenv, o->setenv);
  free(o->setenv);
  free(o->control_path);
  free(o->local_command);
  free(o->remote_command);
  FREE_ARRAY(int, o->num_canonical_domains, o->canonical_domains);
  for (i = 0; i < o->num_permitted_cnames; i++) {
    free(o->permitted_cnames[i].source_list);
    free(o->permitted_cnames[i].target_list);
  }
  FREE_ARRAY(u_int, o->num_revoked_host_keys, o->revoked_host_keys);
  free(o->revoked_host_keys);
  free(o->hostbased_accepted_algos);
  free(o->pubkey_accepted_algos);
  free(o->jump_user);
  free(o->jump_host);
  free(o->jump_extra);
  free(o->ignored_unknown);
  explicit_bzero(o, sizeof(*o));
#undef FREE_ARRAY
}

struct fwdarg {
  char *arg;
  int ispath;
};

/*
 * parse_fwd_field
 * parses the next field in a port forwarding specification.
 * sets fwd to the parsed field and advances p past the colon
 * or sets it to NULL at end of string.
 * returns 0 on success, else non-zero.
 */
static int
parse_fwd_field(char **p, struct fwdarg *fwd)
{
  char *ep, *cp = *p;
  int ispath = 0;

  if (*cp == '\0') {
    *p = NULL;
    return -1;  /* end of string */
  }

  /*
   * A field escaped with square brackets is used literally.
   * XXX - allow ']' to be escaped via backslash?
   */
  if (*cp == '[') {
    /* find matching ']' */
    for (ep = cp + 1; *ep != ']' && *ep != '\0'; ep++) {
      if (*ep == '/')
        ispath = 1;
    }
    /* no matching ']' or not at end of field. */
    if (ep[0] != ']' || (ep[1] != ':' && ep[1] != '\0'))
      return -1;
    /* NUL terminate the field and advance p past the colon */
    *ep++ = '\0';
    if (*ep != '\0')
      *ep++ = '\0';
    fwd->arg = cp + 1;
    fwd->ispath = ispath;
    *p = ep;
    return 0;
  }

  for (cp = *p; *cp != '\0'; cp++) {
    switch (*cp) {
    case '\\':
      memmove(cp, cp + 1, strlen(cp + 1) + 1);
      if (*cp == '\0')
        return -1;
      break;
    case '/':
      ispath = 1;
      break;
    case ':':
      *cp++ = '\0';
      goto done;
    }
  }
done:
  fwd->arg = *p;
  fwd->ispath = ispath;
  *p = cp;
  return 0;
}

/*
 * parse_forward
 * parses a string containing a port forwarding specification of the form:
 *   dynamicfwd == 0
 *  [listenhost:]listenport|listenpath:connecthost:connectport|connectpath
 *  listenpath:connectpath
 *   dynamicfwd == 1
 *  [listenhost:]listenport
 * returns number of arguments parsed or zero on error
 */
int
parse_forward(struct Forward *fwd, const char *fwdspec, int dynamicfwd, int remotefwd)
{
  struct fwdarg fwdargs[4];
  char *p, *cp;
  int i, err;

  memset(fwd, 0, sizeof(*fwd));
  memset(fwdargs, 0, sizeof(fwdargs));

  /*
   * We expand environment variables before checking if we think they're
   * paths so that if ${VAR} expands to a fully qualified path it is
   * treated as a path.
   */
  cp = p = dollar_expand(&err, fwdspec);
  if (p == NULL || err)
    return 0;

  /* skip leading spaces */
  while (isspace((u_char)*cp))
    cp++;

  for (i = 0; i < 4; ++i) {
    if (parse_fwd_field(&cp, &fwdargs[i]) != 0)
      break;
  }

  /* Check for trailing garbage */
  if (cp != NULL && *cp != '\0') {
    i = 0;  /* failure */
  }

  switch (i) {
  case 1:
    if (fwdargs[0].ispath) {
      fwd->listen_path = xstrdup(fwdargs[0].arg);
      fwd->listen_port = PORT_STREAMLOCAL;
    } else {
      fwd->listen_host = NULL;
      fwd->listen_port = a2port(fwdargs[0].arg);
    }
    fwd->connect_host = xstrdup("socks");
    break;

  case 2:
    if (fwdargs[0].ispath && fwdargs[1].ispath) {
      fwd->listen_path = xstrdup(fwdargs[0].arg);
      fwd->listen_port = PORT_STREAMLOCAL;
      fwd->connect_path = xstrdup(fwdargs[1].arg);
      fwd->connect_port = PORT_STREAMLOCAL;
    } else if (fwdargs[1].ispath) {
      fwd->listen_host = NULL;
      fwd->listen_port = a2port(fwdargs[0].arg);
      fwd->connect_path = xstrdup(fwdargs[1].arg);
      fwd->connect_port = PORT_STREAMLOCAL;
    } else {
      fwd->listen_host = xstrdup(fwdargs[0].arg);
      fwd->listen_port = a2port(fwdargs[1].arg);
      fwd->connect_host = xstrdup("socks");
    }
    break;

  case 3:
    if (fwdargs[0].ispath) {
      fwd->listen_path = xstrdup(fwdargs[0].arg);
      fwd->listen_port = PORT_STREAMLOCAL;
      fwd->connect_host = xstrdup(fwdargs[1].arg);
      fwd->connect_port = a2port(fwdargs[2].arg);
    } else if (fwdargs[2].ispath) {
      fwd->listen_host = xstrdup(fwdargs[0].arg);
      fwd->listen_port = a2port(fwdargs[1].arg);
      fwd->connect_path = xstrdup(fwdargs[2].arg);
      fwd->connect_port = PORT_STREAMLOCAL;
    } else {
      fwd->listen_host = NULL;
      fwd->listen_port = a2port(fwdargs[0].arg);
      fwd->connect_host = xstrdup(fwdargs[1].arg);
      fwd->connect_port = a2port(fwdargs[2].arg);
    }
    break;

  case 4:
    fwd->listen_host = xstrdup(fwdargs[0].arg);
    fwd->listen_port = a2port(fwdargs[1].arg);
    fwd->connect_host = xstrdup(fwdargs[2].arg);
    fwd->connect_port = a2port(fwdargs[3].arg);
    break;
  default:
    i = 0; /* failure */
  }

  free(p);

  if (dynamicfwd) {
    if (!(i == 1 || i == 2))
      goto fail_free;
  } else {
    if (!(i == 3 || i == 4)) {
      if (fwd->connect_path == NULL &&
          fwd->listen_path == NULL)
        goto fail_free;
    }
    if (fwd->connect_port <= 0 && fwd->connect_path == NULL)
      goto fail_free;
  }

  if ((fwd->listen_port < 0 && fwd->listen_path == NULL) ||
      (!remotefwd && fwd->listen_port == 0))
    goto fail_free;
  if (fwd->connect_host != NULL &&
      strlen(fwd->connect_host) >= NI_MAXHOST)
    goto fail_free;
  /*
   * XXX - if connecting to a remote socket, max sun len may not
   * match this host
   */
  if (fwd->connect_path != NULL &&
      strlen(fwd->connect_path) >= PATH_MAX_SUN)
    goto fail_free;
  if (fwd->listen_host != NULL &&
      strlen(fwd->listen_host) >= NI_MAXHOST)
    goto fail_free;
  if (fwd->listen_path != NULL &&
      strlen(fwd->listen_path) >= PATH_MAX_SUN)
    goto fail_free;

  return (i);

 fail_free:
  free(fwd->connect_host);
  fwd->connect_host = NULL;
  free(fwd->connect_path);
  fwd->connect_path = NULL;
  free(fwd->listen_host);
  fwd->listen_host = NULL;
  free(fwd->listen_path);
  fwd->listen_path = NULL;
  return (0);
}

int
ssh_valid_hostname(const char *s)
{
  size_t i;

  if (*s == '-')
    return 0;
  for (i = 0; s[i] != 0; i++) {
    if (strchr("'`\"$\\;&<>|(){},", s[i]) != NULL ||
        isspace((u_char)s[i]) || iscntrl((u_char)s[i]))
      return 0;
  }
  return 1;
}

int
ssh_valid_ruser(const char *s)
{
  size_t i;

  if (*s == '-')
    return 0;
  for (i = 0; s[i] != 0; i++) {
    if (iscntrl((u_char)s[i]))
      return 0;
    if (strchr("'`\";&<>|(){}$\\", s[i]) != NULL)
      return 0;
    /* Disallow '-' after whitespace */
    if (isspace((u_char)s[i]) && s[i + 1] == '-')
      return 0;
  }
  return 1;
}

int
parse_jump(const char *s, Options *o, int strict, int active)
{
  char *orig = NULL, *sdup = NULL, *cp;
  char *tmp_user = NULL, *tmp_host = NULL, *host = NULL, *user = NULL;
  int r, ret = -1, tmp_port = -1, port = -1, first = 1;

  if (strcasecmp(s, "none") == 0) {
    if (active && o->jump_host == NULL) {
      o->jump_host = xstrdup("none");
      o->jump_port = 0;
    }
    return 0;
  }

  orig = xstrdup(s);
  if ((cp = strchr(orig, '#')) != NULL)
    *cp = '\0';
  rtrim(orig);

  active &= o->proxy_command == NULL && o->jump_host == NULL;
  sdup = xstrdup(orig);
  do {
    /* Work backwards through string */
    if ((cp = strrchr(sdup, ',')) == NULL)
      cp = sdup; /* last */
    else
      *cp++ = '\0';

    r = parse_ssh_uri(cp, &tmp_user, &tmp_host, &tmp_port);
    if (r == -1 || (r == 1 && parse_user_host_port(cp,
        &tmp_user, &tmp_host, &tmp_port) != 0))
      goto out; /* error already logged */
    if (strict) {
      if (!ssh_valid_hostname(tmp_host)) {
        error_f("invalid hostname \"%s\"", tmp_host);
        goto out;
      }
      if (tmp_user != NULL && !ssh_valid_ruser(tmp_user)) {
        error_f("invalid username \"%s\"", tmp_user);
        goto out;
      }
    }
    if (first) {
      user = tmp_user;
      host = tmp_host;
      port = tmp_port;
      tmp_user = tmp_host = NULL; /* transferred */
    }
    first = 0; /* only check syntax for subsequent hosts */
    free(tmp_user);
    free(tmp_host);
    tmp_user = tmp_host = NULL;
    tmp_port = -1;
  } while (cp != sdup);

  /* success */
  if (active) {
    o->jump_user = user;
    o->jump_host = host;
    o->jump_port = port;
    o->proxy_command = xstrdup("none");
    user = host = NULL; /* transferred */
    if (orig != NULL && (cp = strrchr(orig, ',')) != NULL) {
      o->jump_extra = xstrdup(orig);
      o->jump_extra[cp - orig] = '\0';
    }
  }
  ret = 0;
 out:
  free(orig);
  free(sdup);
  free(tmp_user);
  free(tmp_host);
  free(user);
  free(host);
  return ret;
}

int
parse_ssh_uri(const char *uri, char **userp, char **hostp, int *portp)
{
  char *user = NULL, *host = NULL, *path = NULL;
  int r, port;

  r = parse_uri("ssh", uri, &user, &host, &port, &path);
  if (r == 0 && path != NULL)
    r = -1;   /* path not allowed */
  if (r == 0) {
    if (userp != NULL) {
      *userp = user;
      user = NULL;
    }
    if (hostp != NULL) {
      *hostp = host;
      host = NULL;
    }
    if (portp != NULL)
      *portp = port;
  }
  free(user);
  free(host);
  free(path);
  return r;
}

/* XXX the following is a near-verbatim 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 oCompression:
    return fmt_multistate_int(val, multistate_compression);
  case oVerifyHostKeyDNS:
  case oUpdateHostkeys:
    return fmt_multistate_int(val, multistate_yesnoask);
  case oStrictHostKeyChecking:
    return fmt_multistate_int(val, multistate_strict_hostkey);
  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 oSessionType:
    return fmt_multistate_int(val, multistate_sessiontype);
  case oCanonicalizeHostname:
    return fmt_multistate_int(val, multistate_canonicalizehostname);
  case oAddKeysToAgent:
    return fmt_multistate_int(val, multistate_yesnoaskconfirm);
  case oPubkeyAuthentication:
    return fmt_multistate_int(val, multistate_pubkey_auth);
  case oTCPKeepAlive:
    return fmt_multistate_int(val, multistate_keepalives);
  case oFingerprintHash:
    return ssh_digest_alg_name(val);
  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)
{
  if (code == oObscureKeystrokeTiming) {
    if (val == 0) {
      printf("%s no\n", lookup_opcode_name(code));
      return;
    } else if (val == SSH_KEYSTROKE_DEFAULT_INTERVAL_MS) {
      printf("%s yes\n", lookup_opcode_name(code));
      return;
    }
    /* FALLTHROUGH */
  }
  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));
  if (count == 0)
    printf(" none");
  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 && fwd->connect_host != NULL &&
        strcmp(fwd->connect_host, "socks") != 0)
      continue;
    if (code == oLocalForward && fwd->connect_host != NULL &&
        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, r;
  char buf[8], *all_key;

  /*
   * Expand HostKeyAlgorithms name lists. This isn't handled in
   * fill_default_options() like the other algorithm lists because
   * the host key algorithms are by default dynamically chosen based
   * on the host's keys found in known_hosts.
   */
  all_key = sshkey_alg_list(0, 0, 1, ',');
  if ((r = kex_assemble_names(&o->hostkeyalgorithms, kex_default_pk_alg(),
      all_key)) != 0)
    fatal_fr(r, "expand HostKeyAlgorithms");
  free(all_key);

  /* Most interesting options first: user, host, port */
  dump_cfg_string(oHost, o->host_arg);
  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(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(oClearAllForwardings, o->clear_forwardings);
  dump_cfg_fmtint(oExitOnForwardFailure, o->exit_on_forward_failure);
  dump_cfg_fmtint(oFingerprintHash, o->fingerprint_hash);
  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(oProxyUseFdpass, o->proxy_use_fdpass);
  dump_cfg_fmtint(oPubkeyAuthentication, o->pubkey_authentication);
  dump_cfg_fmtint(oRequestTTY, o->request_tty);
  dump_cfg_fmtint(oSessionType, o->session_type);
  dump_cfg_fmtint(oStdinNull, o->stdin_null);
  dump_cfg_fmtint(oForkAfterAuthentication, o->fork_after_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(oVerifyHostKeyDNS, o->verify_host_key_dns);
  dump_cfg_fmtint(oVisualHostKey, o->visual_host_key);
  dump_cfg_fmtint(oUpdateHostkeys, o->update_hostkeys);
  dump_cfg_fmtint(oEnableEscapeCommandline, o->enable_escape_commandline);
  dump_cfg_fmtint(oWarnWeakCrypto, o->warn_weak_crypto);

  /* Integer options */
  dump_cfg_int(oCanonicalizeMaxDots, o->canonicalize_max_dots);
  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);
  dump_cfg_int(oRequiredRSASize, o->required_rsa_size);
  dump_cfg_int(oObscureKeystrokeTiming,
      o->obscure_keystroke_timing_interval);

  /* String options */
  dump_cfg_string(oBindAddress, o->bind_address);
  dump_cfg_string(oBindInterface, o->bind_interface);
  dump_cfg_string(oCiphers, o->ciphers);
  dump_cfg_string(oControlPath, o->control_path);
  dump_cfg_string(oHostKeyAlgorithms, o->hostkeyalgorithms);
  dump_cfg_string(oHostKeyAlias, o->host_key_alias);
  dump_cfg_string(oHostbasedAcceptedAlgorithms, o->hostbased_accepted_algos);
  dump_cfg_string(oIdentityAgent, o->identity_agent);
  dump_cfg_string(oIgnoreUnknown, o->ignored_unknown);
  dump_cfg_string(oKbdInteractiveDevices, o->kbd_interactive_devices);
  dump_cfg_string(oKexAlgorithms, o->kex_algorithms);
  dump_cfg_string(oCASignatureAlgorithms, o->ca_sign_algorithms);
  dump_cfg_string(oLocalCommand, o->local_command);
  dump_cfg_string(oRemoteCommand, o->remote_command);
  dump_cfg_string(oLogLevel, log_level_name(o->log_level));
  dump_cfg_string(oMacs, o->macs);
#ifdef ENABLE_PKCS11
  dump_cfg_string(oPKCS11Provider, o->pkcs11_provider);
#endif
  dump_cfg_string(oSecurityKeyProvider, o->sk_provider);
  dump_cfg_string(oPreferredAuthentications, o->preferred_authentications);
  dump_cfg_string(oPubkeyAcceptedAlgorithms, o->pubkey_accepted_algos);
  dump_cfg_string(oXAuthLocation, o->xauth_location);
  dump_cfg_string(oKnownHostsCommand, o->known_hosts_command);
  dump_cfg_string(oTag, o->tag);
  dump_cfg_string(oVersionAddendum, o->version_addendum);

  /* Forwards */
  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(oCertificateFile, o->num_certificate_files, o->certificate_files);
  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_oneline(oRevokedHostKeys, o->num_revoked_host_keys, o->revoked_host_keys);
  dump_cfg_strarray(oSendEnv, o->num_send_env, o->send_env);
  dump_cfg_strarray(oSetEnv, o->num_setenv, o->setenv);
  dump_cfg_strarray_oneline(oLogVerbose,
      o->num_log_verbose, o->log_verbose);
  dump_cfg_strarray_oneline(oChannelTimeout,
      o->num_channel_timeouts, o->channel_timeouts);

  /* Special cases */

  /* PermitRemoteOpen */
  if (o->num_permitted_remote_opens == 0)
    printf("%s any\n", lookup_opcode_name(oPermitRemoteOpen));
  else
    dump_cfg_strarray_oneline(oPermitRemoteOpen,
        o->num_permitted_remote_opens, o->permitted_remote_opens);

  /* AddKeysToAgent */
  if (o->add_keys_to_agent_lifespan <= 0)
    dump_cfg_fmtint(oAddKeysToAgent, o->add_keys_to_agent);
  else {
    printf("addkeystoagent%s %d\n",
        o->add_keys_to_agent == 3 ? " confirm" : "",
        o->add_keys_to_agent_lifespan);
  }

  /* oForwardAgent */
  if (o->forward_agent_sock_path == NULL)
    dump_cfg_fmtint(oForwardAgent, o->forward_agent);
  else
    dump_cfg_string(oForwardAgent, o->forward_agent_sock_path);

  /* 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 */
  printf("canonicalizepermittedcnames");
  if (o->num_permitted_cnames == 0)
    printf(" none");
  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");

  /* 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(buf, o->escape_char, VIS_WHITE, 0);
    printf("escapechar %s\n", buf);
  }

  /* oIPQoS */
  printf("ipqos %s ", iptos2str(o->ip_qos_interactive));
  printf("%s\n", iptos2str(o->ip_qos_bulk));

  /* oRekeyLimit */
  printf("rekeylimit %llu %d\n",
      (unsigned long long)o->rekey_limit, o->rekey_interval);

  /* oStreamLocalBindMask */
  printf("streamlocalbindmask 0%o\n",
      o->fwd_opts.streamlocal_bind_mask);

  /* oLogFacility */
  printf("syslogfacility %s\n", log_facility_name(o->log_facility));

  /* oProxyCommand / oProxyJump */
  if (o->jump_host == NULL)
    dump_cfg_string(oProxyCommand, o->proxy_command);
  else {
    /* Check for numeric addresses */
    i = strchr(o->jump_host, ':') != NULL ||
        strspn(o->jump_host, "1234567890.") == strlen(o->jump_host);
    snprintf(buf, sizeof(buf), "%d", o->jump_port);
    printf("proxyjump %s%s%s%s%s%s%s%s%s\n",
        /* optional additional jump spec */
        o->jump_extra == NULL ? "" : o->jump_extra,
        o->jump_extra == NULL ? "" : ",",
        /* optional user */
        o->jump_user == NULL ? "" : o->jump_user,
        o->jump_user == NULL ? "" : "@",
        /* opening [ if hostname is numeric */
        i ? "[" : "",
        /* mandatory hostname */
        o->jump_host,
        /* closing ] if hostname is numeric */
        i ? "]" : "",
        /* optional port number */
        o->jump_port <= 0 ? "" : ":",
        o->jump_port <= 0 ? "" : buf);
  }
}

Coverage Report

Created: 2026-10-13 06:56