OpenBSD-4.6/usr.bin/ssh/readconf.c
/* $OpenBSD: readconf.c,v 1.177 2009/06/27 09:35:06 andreas 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 <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "xmalloc.h"
#include "ssh.h"
#include "compat.h"
#include "cipher.h"
#include "pathnames.h"
#include "log.h"
#include "key.h"
#include "readconf.h"
#include "match.h"
#include "misc.h"
#include "buffer.h"
#include "kex.h"
#include "mac.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
Cipher 3des
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
Cipher none
PasswordAuthentication no
Host vpn.fake.com
Tunnel yes
TunnelDevice 3
# Defaults for various options
Host *
ForwardAgent no
ForwardX11 no
PasswordAuthentication yes
RSAAuthentication yes
RhostsRSAAuthentication yes
StrictHostKeyChecking yes
TcpKeepAlive no
IdentityFile ~/.ssh/identity
Port 22
EscapeChar ~
*/
/* Keyword tokens. */
typedef enum {
oBadOption,
oForwardAgent, oForwardX11, oForwardX11Trusted, oGatewayPorts,
oExitOnForwardFailure,
oPasswordAuthentication, oRSAAuthentication,
oChallengeResponseAuthentication, oXAuthLocation,
oIdentityFile, oHostName, oPort, oCipher, oRemoteForward, oLocalForward,
oUser, oHost, oEscapeChar, oRhostsRSAAuthentication, oProxyCommand,
oGlobalKnownHostsFile, oUserKnownHostsFile, oConnectionAttempts,
oBatchMode, oCheckHostIP, oStrictHostKeyChecking, oCompression,
oCompressionLevel, oTCPKeepAlive, oNumberOfPasswordPrompts,
oUsePrivilegedPort, oLogLevel, oCiphers, oProtocol, oMacs,
oGlobalKnownHostsFile2, oUserKnownHostsFile2, oPubkeyAuthentication,
oKbdInteractiveAuthentication, oKbdInteractiveDevices, oHostKeyAlias,
oDynamicForward, oPreferredAuthentications, oHostbasedAuthentication,
oHostKeyAlgorithms, oBindAddress, oSmartcardDevice,
oClearAllForwardings, oNoHostAuthenticationForLocalhost,
oEnableSSHKeysign, oRekeyLimit, oVerifyHostKeyDNS, oConnectTimeout,
oAddressFamily, oGssAuthentication, oGssDelegateCreds,
oServerAliveInterval, oServerAliveCountMax, oIdentitiesOnly,
oSendEnv, oControlPath, oControlMaster, oHashKnownHosts,
oTunnel, oTunnelDevice, oLocalCommand, oPermitLocalCommand,
oVisualHostKey, oUseRoaming, oZeroKnowledgePasswordAuthentication,
oDeprecated, oUnsupported
} OpCodes;
/* Textual representations of the tokens. */
static struct {
const char *name;
OpCodes opcode;
} keywords[] = {
{ "forwardagent", oForwardAgent },
{ "forwardx11", oForwardX11 },
{ "forwardx11trusted", oForwardX11Trusted },
{ "exitonforwardfailure", oExitOnForwardFailure },
{ "xauthlocation", oXAuthLocation },
{ "gatewayports", oGatewayPorts },
{ "useprivilegedport", oUsePrivilegedPort },
{ "rhostsauthentication", oDeprecated },
{ "passwordauthentication", oPasswordAuthentication },
{ "kbdinteractiveauthentication", oKbdInteractiveAuthentication },
{ "kbdinteractivedevices", oKbdInteractiveDevices },
{ "rsaauthentication", oRSAAuthentication },
{ "pubkeyauthentication", oPubkeyAuthentication },
{ "dsaauthentication", oPubkeyAuthentication }, /* alias */
{ "rhostsrsaauthentication", oRhostsRSAAuthentication },
{ "hostbasedauthentication", oHostbasedAuthentication },
{ "challengeresponseauthentication", oChallengeResponseAuthentication },
{ "skeyauthentication", oChallengeResponseAuthentication }, /* alias */
{ "tisauthentication", oChallengeResponseAuthentication }, /* alias */
{ "kerberosauthentication", oUnsupported },
{ "kerberostgtpassing", oUnsupported },
{ "afstokenpassing", oUnsupported },
#if defined(GSSAPI)
{ "gssapiauthentication", oGssAuthentication },
{ "gssapidelegatecredentials", oGssDelegateCreds },
#else
{ "gssapiauthentication", oUnsupported },
{ "gssapidelegatecredentials", oUnsupported },
#endif
{ "fallbacktorsh", oDeprecated },
{ "usersh", oDeprecated },
{ "identityfile", oIdentityFile },
{ "identityfile2", oIdentityFile }, /* obsolete */
{ "identitiesonly", oIdentitiesOnly },
{ "hostname", oHostName },
{ "hostkeyalias", oHostKeyAlias },
{ "proxycommand", oProxyCommand },
{ "port", oPort },
{ "cipher", oCipher },
{ "ciphers", oCiphers },
{ "macs", oMacs },
{ "protocol", oProtocol },
{ "remoteforward", oRemoteForward },
{ "localforward", oLocalForward },
{ "user", oUser },
{ "host", oHost },
{ "escapechar", oEscapeChar },
{ "globalknownhostsfile", oGlobalKnownHostsFile },
{ "globalknownhostsfile2", oGlobalKnownHostsFile2 }, /* obsolete */
{ "userknownhostsfile", oUserKnownHostsFile },
{ "userknownhostsfile2", oUserKnownHostsFile2 }, /* obsolete */
{ "connectionattempts", oConnectionAttempts },
{ "batchmode", oBatchMode },
{ "checkhostip", oCheckHostIP },
{ "stricthostkeychecking", oStrictHostKeyChecking },
{ "compression", oCompression },
{ "compressionlevel", oCompressionLevel },
{ "tcpkeepalive", oTCPKeepAlive },
{ "keepalive", oTCPKeepAlive }, /* obsolete */
{ "numberofpasswordprompts", oNumberOfPasswordPrompts },
{ "loglevel", oLogLevel },
{ "dynamicforward", oDynamicForward },
{ "preferredauthentications", oPreferredAuthentications },
{ "hostkeyalgorithms", oHostKeyAlgorithms },
{ "bindaddress", oBindAddress },
#ifdef SMARTCARD
{ "smartcarddevice", oSmartcardDevice },
#else
{ "smartcarddevice", oUnsupported },
#endif
{ "clearallforwardings", oClearAllForwardings },
{ "enablesshkeysign", oEnableSSHKeysign },
{ "verifyhostkeydns", oVerifyHostKeyDNS },
{ "nohostauthenticationforlocalhost", oNoHostAuthenticationForLocalhost },
{ "rekeylimit", oRekeyLimit },
{ "connecttimeout", oConnectTimeout },
{ "addressfamily", oAddressFamily },
{ "serveraliveinterval", oServerAliveInterval },
{ "serveralivecountmax", oServerAliveCountMax },
{ "sendenv", oSendEnv },
{ "controlpath", oControlPath },
{ "controlmaster", oControlMaster },
{ "hashknownhosts", oHashKnownHosts },
{ "tunnel", oTunnel },
{ "tunneldevice", oTunnelDevice },
{ "localcommand", oLocalCommand },
{ "permitlocalcommand", oPermitLocalCommand },
{ "visualhostkey", oVisualHostKey },
{ "useroaming", oUseRoaming },
#ifdef JPAKE
{ "zeroknowledgepasswordauthentication",
oZeroKnowledgePasswordAuthentication },
#else
{ "zeroknowledgepasswordauthentication", oUnsupported },
#endif
{ NULL, oBadOption }
};
/*
* Adds a local TCP/IP port forward to options. Never returns if there is an
* error.
*/
void
add_local_forward(Options *options, const Forward *newfwd)
{
Forward *fwd;
extern uid_t original_real_uid;
if (newfwd->listen_port < IPPORT_RESERVED && original_real_uid != 0)
fatal("Privileged ports can only be forwarded by root.");
if (options->num_local_forwards >= SSH_MAX_FORWARDS_PER_DIRECTION)
fatal("Too many local forwards (max %d).", SSH_MAX_FORWARDS_PER_DIRECTION);
fwd = &options->local_forwards[options->num_local_forwards++];
fwd->listen_host = newfwd->listen_host;
fwd->listen_port = newfwd->listen_port;
fwd->connect_host = newfwd->connect_host;
fwd->connect_port = newfwd->connect_port;
}
/*
* Adds a remote TCP/IP port forward to options. Never returns if there is
* an error.
*/
void
add_remote_forward(Options *options, const Forward *newfwd)
{
Forward *fwd;
if (options->num_remote_forwards >= SSH_MAX_FORWARDS_PER_DIRECTION)
fatal("Too many remote forwards (max %d).",
SSH_MAX_FORWARDS_PER_DIRECTION);
fwd = &options->remote_forwards[options->num_remote_forwards++];
fwd->listen_host = newfwd->listen_host;
fwd->listen_port = newfwd->listen_port;
fwd->connect_host = newfwd->connect_host;
fwd->connect_port = newfwd->connect_port;
}
static void
clear_forwardings(Options *options)
{
int i;
for (i = 0; i < options->num_local_forwards; i++) {
if (options->local_forwards[i].listen_host != NULL)
xfree(options->local_forwards[i].listen_host);
xfree(options->local_forwards[i].connect_host);
}
options->num_local_forwards = 0;
for (i = 0; i < options->num_remote_forwards; i++) {
if (options->remote_forwards[i].listen_host != NULL)
xfree(options->remote_forwards[i].listen_host);
xfree(options->remote_forwards[i].connect_host);
}
options->num_remote_forwards = 0;
options->tun_open = SSH_TUNMODE_NO;
}
/*
* Returns the number of the token pointed to by cp or oBadOption.
*/
static OpCodes
parse_token(const char *cp, const char *filename, int linenum)
{
u_int i;
for (i = 0; keywords[i].name; i++)
if (strcasecmp(cp, keywords[i].name) == 0)
return keywords[i].opcode;
error("%s: line %d: Bad configuration option: %s",
filename, linenum, cp);
return oBadOption;
}
/*
* Processes a single option line as used in the configuration files. This
* only sets those values that have not already been set.
*/
#define WHITESPACE " \t\r\n"
int
process_config_line(Options *options, const char *host,
char *line, const char *filename, int linenum,
int *activep)
{
char *s, **charptr, *endofnumber, *keyword, *arg, *arg2, fwdarg[256];
int opcode, *intptr, value, value2, scale;
LogLevel *log_level_ptr;
long long orig, val64;
size_t len;
Forward fwd;
/* Strip trailing whitespace */
for (len = strlen(line) - 1; len > 0; len--) {
if (strchr(WHITESPACE, line[len]) == NULL)
break;
line[len] = '\0';
}
s = line;
/* Get the keyword. (Each line is supposed to begin with a keyword). */
if ((keyword = strdelim(&s)) == NULL)
return 0;
/* Ignore leading whitespace. */
if (*keyword == '\0')
keyword = strdelim(&s);
if (keyword == NULL || !*keyword || *keyword == '\n' || *keyword == '#')
return 0;
opcode = parse_token(keyword, filename, linenum);
switch (opcode) {
case oBadOption:
/* don't panic, but count bad options */
return -1;
/* NOTREACHED */
case oConnectTimeout:
intptr = &options->connection_timeout;
parse_time:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: missing time value.",
filename, linenum);
if ((value = convtime(arg)) == -1)
fatal("%s line %d: invalid time value.",
filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oForwardAgent:
intptr = &options->forward_agent;
parse_flag:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing yes/no argument.", filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = 1;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = 0;
else
fatal("%.200s line %d: Bad yes/no argument.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oForwardX11:
intptr = &options->forward_x11;
goto parse_flag;
case oForwardX11Trusted:
intptr = &options->forward_x11_trusted;
goto parse_flag;
case oGatewayPorts:
intptr = &options->gateway_ports;
goto parse_flag;
case oExitOnForwardFailure:
intptr = &options->exit_on_forward_failure;
goto parse_flag;
case oUsePrivilegedPort:
intptr = &options->use_privileged_port;
goto parse_flag;
case oPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case oZeroKnowledgePasswordAuthentication:
intptr = &options->zero_knowledge_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:
intptr = &options->pubkey_authentication;
goto parse_flag;
case oRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case oRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case oHostbasedAuthentication:
intptr = &options->hostbased_authentication;
goto parse_flag;
case oChallengeResponseAuthentication:
intptr = &options->challenge_response_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;
goto parse_yesnoask;
case oStrictHostKeyChecking:
intptr = &options->strict_host_key_checking;
parse_yesnoask:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing yes/no/ask argument.",
filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = 1;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = 0;
else if (strcmp(arg, "ask") == 0)
value = 2;
else
fatal("%.200s line %d: Bad yes/no/ask argument.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oCompression:
intptr = &options->compression;
goto parse_flag;
case oTCPKeepAlive:
intptr = &options->tcp_keep_alive;
goto parse_flag;
case oNoHostAuthenticationForLocalhost:
intptr = &options->no_host_authentication_for_localhost;
goto parse_flag;
case oNumberOfPasswordPrompts:
intptr = &options->number_of_password_prompts;
goto parse_int;
case oCompressionLevel:
intptr = &options->compression_level;
goto parse_int;
case oRekeyLimit:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] < '0' || arg[0] > '9')
fatal("%.200s line %d: Bad number.", filename, linenum);
orig = val64 = strtoll(arg, &endofnumber, 10);
if (arg == endofnumber)
fatal("%.200s line %d: Bad number.", filename, linenum);
switch (toupper(*endofnumber)) {
case '\0':
scale = 1;
break;
case 'K':
scale = 1<<10;
break;
case 'M':
scale = 1<<20;
break;
case 'G':
scale = 1<<30;
break;
default:
fatal("%.200s line %d: Invalid RekeyLimit suffix",
filename, linenum);
}
val64 *= scale;
/* detect integer wrap and too-large limits */
if ((val64 / scale) != orig || val64 > UINT_MAX)
fatal("%.200s line %d: RekeyLimit too large",
filename, linenum);
if (val64 < 16)
fatal("%.200s line %d: RekeyLimit too small",
filename, linenum);
if (*activep && options->rekey_limit == -1)
options->rekey_limit = (u_int32_t)val64;
break;
case oIdentityFile:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (*activep) {
intptr = &options->num_identity_files;
if (*intptr >= SSH_MAX_IDENTITY_FILES)
fatal("%.200s line %d: Too many identity files specified (max %d).",
filename, linenum, SSH_MAX_IDENTITY_FILES);
charptr = &options->identity_files[*intptr];
*charptr = xstrdup(arg);
*intptr = *intptr + 1;
}
break;
case oXAuthLocation:
charptr=&options->xauth_location;
goto parse_string;
case oUser:
charptr = &options->user;
parse_string:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (*activep && *charptr == NULL)
*charptr = xstrdup(arg);
break;
case oGlobalKnownHostsFile:
charptr = &options->system_hostfile;
goto parse_string;
case oUserKnownHostsFile:
charptr = &options->user_hostfile;
goto parse_string;
case oGlobalKnownHostsFile2:
charptr = &options->system_hostfile2;
goto parse_string;
case oUserKnownHostsFile2:
charptr = &options->user_hostfile2;
goto parse_string;
case oHostName:
charptr = &options->hostname;
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 oSmartcardDevice:
charptr = &options->smartcard_device;
goto parse_string;
case oProxyCommand:
charptr = &options->proxy_command;
parse_command:
if (s == NULL)
fatal("%.200s line %d: Missing argument.", filename, linenum);
len = strspn(s, WHITESPACE "=");
if (*activep && *charptr == NULL)
*charptr = xstrdup(s + len);
return 0;
case oPort:
intptr = &options->port;
parse_int:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] < '0' || arg[0] > '9')
fatal("%.200s line %d: Bad number.", filename, linenum);
/* Octal, decimal, or hex format? */
value = strtol(arg, &endofnumber, 0);
if (arg == endofnumber)
fatal("%.200s line %d: Bad number.", filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oConnectionAttempts:
intptr = &options->connection_attempts;
goto parse_int;
case oCipher:
intptr = &options->cipher;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = cipher_number(arg);
if (value == -1)
fatal("%.200s line %d: Bad cipher '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == -1)
*intptr = value;
break;
case oCiphers:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%.200s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case oMacs:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!mac_valid(arg))
fatal("%.200s line %d: Bad SSH2 Mac spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->macs == NULL)
options->macs = xstrdup(arg);
break;
case oHostKeyAlgorithms:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (!key_names_valid2(arg))
fatal("%.200s line %d: Bad protocol 2 host key algorithms '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && options->hostkeyalgorithms == NULL)
options->hostkeyalgorithms = xstrdup(arg);
break;
case oProtocol:
intptr = &options->protocol;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%.200s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case oLogLevel:
log_level_ptr = &options->log_level;
arg = strdelim(&s);
value = log_level_number(arg);
if (value == SYSLOG_LEVEL_NOT_SET)
fatal("%.200s line %d: unsupported log level '%s'",
filename, linenum, arg ? arg : "<NONE>");
if (*activep && *log_level_ptr == SYSLOG_LEVEL_NOT_SET)
*log_level_ptr = (LogLevel) value;
break;
case oLocalForward:
case oRemoteForward:
case oDynamicForward:
arg = strdelim(&s);
if (arg == NULL || *arg == '\0')
fatal("%.200s line %d: Missing port argument.",
filename, linenum);
if (opcode == oLocalForward ||
opcode == oRemoteForward) {
arg2 = strdelim(&s);
if (arg2 == NULL || *arg2 == '\0')
fatal("%.200s line %d: Missing target argument.",
filename, linenum);
/* construct a string for parse_forward */
snprintf(fwdarg, sizeof(fwdarg), "%s:%s", arg, arg2);
} else if (opcode == oDynamicForward) {
strlcpy(fwdarg, arg, sizeof(fwdarg));
}
if (parse_forward(&fwd, fwdarg,
opcode == oDynamicForward ? 1 : 0,
opcode == oRemoteForward ? 1 : 0) == 0)
fatal("%.200s line %d: Bad forwarding specification.",
filename, linenum);
if (*activep) {
if (opcode == oLocalForward ||
opcode == oDynamicForward)
add_local_forward(options, &fwd);
else if (opcode == oRemoteForward)
add_remote_forward(options, &fwd);
}
break;
case oClearAllForwardings:
intptr = &options->clear_forwardings;
goto parse_flag;
case oHost:
*activep = 0;
while ((arg = strdelim(&s)) != NULL && *arg != '\0')
if (match_pattern(host, arg)) {
debug("Applying options for %.100s", arg);
*activep = 1;
break;
}
/* Avoid garbage check below, as strdelim is done. */
return 0;
case oEscapeChar:
intptr = &options->escape_char;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
if (arg[0] == '^' && arg[2] == 0 &&
(u_char) arg[1] >= 64 && (u_char) arg[1] < 128)
value = (u_char) arg[1] & 31;
else if (strlen(arg) == 1)
value = (u_char) arg[0];
else if (strcmp(arg, "none") == 0)
value = SSH_ESCAPECHAR_NONE;
else {
fatal("%.200s line %d: Bad escape character.",
filename, linenum);
/* NOTREACHED */
value = 0; /* Avoid compiler warning. */
}
if (*activep && *intptr == -1)
*intptr = value;
break;
case oAddressFamily:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: missing address family.",
filename, linenum);
intptr = &options->address_family;
if (strcasecmp(arg, "inet") == 0)
value = AF_INET;
else if (strcasecmp(arg, "inet6") == 0)
value = AF_INET6;
else if (strcasecmp(arg, "any") == 0)
value = AF_UNSPEC;
else
fatal("Unsupported AddressFamily \"%s\"", arg);
if (*activep && *intptr == -1)
*intptr = value;
break;
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:
while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
if (strchr(arg, '=') != NULL)
fatal("%s line %d: Invalid environment name.",
filename, linenum);
if (!*activep)
continue;
if (options->num_send_env >= MAX_SEND_ENV)
fatal("%s line %d: too many send env.",
filename, linenum);
options->send_env[options->num_send_env++] =
xstrdup(arg);
}
break;
case oControlPath:
charptr = &options->control_path;
goto parse_string;
case oControlMaster:
intptr = &options->control_master;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing ControlMaster argument.",
filename, linenum);
value = 0; /* To avoid compiler warning... */
if (strcmp(arg, "yes") == 0 || strcmp(arg, "true") == 0)
value = SSHCTL_MASTER_YES;
else if (strcmp(arg, "no") == 0 || strcmp(arg, "false") == 0)
value = SSHCTL_MASTER_NO;
else if (strcmp(arg, "auto") == 0)
value = SSHCTL_MASTER_AUTO;
else if (strcmp(arg, "ask") == 0)
value = SSHCTL_MASTER_ASK;
else if (strcmp(arg, "autoask") == 0)
value = SSHCTL_MASTER_AUTO_ASK;
else
fatal("%.200s line %d: Bad ControlMaster argument.",
filename, linenum);
if (*activep && *intptr == -1)
*intptr = value;
break;
case oHashKnownHosts:
intptr = &options->hash_known_hosts;
goto parse_flag;
case oTunnel:
intptr = &options->tun_open;
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing yes/point-to-point/"
"ethernet/no argument.", filename, linenum);
value = 0; /* silence compiler */
if (strcasecmp(arg, "ethernet") == 0)
value = SSH_TUNMODE_ETHERNET;
else if (strcasecmp(arg, "point-to-point") == 0)
value = SSH_TUNMODE_POINTOPOINT;
else if (strcasecmp(arg, "yes") == 0)
value = SSH_TUNMODE_DEFAULT;
else if (strcasecmp(arg, "no") == 0)
value = SSH_TUNMODE_NO;
else
fatal("%s line %d: Bad yes/point-to-point/ethernet/"
"no argument: %s", filename, linenum, arg);
if (*activep)
*intptr = value;
break;
case oTunnelDevice:
arg = strdelim(&s);
if (!arg || *arg == '\0')
fatal("%.200s line %d: Missing argument.", filename, linenum);
value = a2tun(arg, &value2);
if (value == SSH_TUNID_ERR)
fatal("%.200s line %d: Bad tun device.", filename, linenum);
if (*activep) {
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 oVisualHostKey:
intptr = &options->visual_host_key;
goto parse_flag;
case oUseRoaming:
intptr = &options->use_roaming;
goto parse_flag;
case oDeprecated:
debug("%s line %d: Deprecated option \"%s\"",
filename, linenum, keyword);
return 0;
case oUnsupported:
error("%s line %d: Unsupported option \"%s\"",
filename, linenum, keyword);
return 0;
default:
fatal("process_config_line: Unimplemented opcode %d", opcode);
}
/* Check that there is no garbage at end of line. */
if ((arg = strdelim(&s)) != NULL && *arg != '\0') {
fatal("%.200s line %d: garbage at end of line; \"%.200s\".",
filename, linenum, arg);
}
return 0;
}
/*
* 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, const char *host, Options *options,
int checkperm)
{
FILE *f;
char line[1024];
int active, linenum;
int bad_options = 0;
if ((f = fopen(filename, "r")) == NULL)
return 0;
if (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.
*/
active = 1;
linenum = 0;
while (fgets(line, sizeof(line), f)) {
/* Update line number counter. */
linenum++;
if (process_config_line(options, host, line, filename, linenum, &active) != 0)
bad_options++;
}
fclose(f);
if (bad_options > 0)
fatal("%s: terminating, %d bad configuration options",
filename, bad_options);
return 1;
}
/*
* 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->forward_agent = -1;
options->forward_x11 = -1;
options->forward_x11_trusted = -1;
options->exit_on_forward_failure = -1;
options->xauth_location = NULL;
options->gateway_ports = -1;
options->use_privileged_port = -1;
options->rsa_authentication = -1;
options->pubkey_authentication = -1;
options->challenge_response_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->rhosts_rsa_authentication = -1;
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->compression_level = -1;
options->port = -1;
options->address_family = -1;
options->connection_attempts = -1;
options->connection_timeout = -1;
options->number_of_password_prompts = -1;
options->cipher = -1;
options->ciphers = NULL;
options->macs = NULL;
options->hostkeyalgorithms = NULL;
options->protocol = SSH_PROTO_UNKNOWN;
options->num_identity_files = 0;
options->hostname = NULL;
options->host_key_alias = NULL;
options->proxy_command = NULL;
options->user = NULL;
options->escape_char = -1;
options->system_hostfile = NULL;
options->user_hostfile = NULL;
options->system_hostfile2 = NULL;
options->user_hostfile2 = NULL;
options->num_local_forwards = 0;
options->num_remote_forwards = 0;
options->clear_forwardings = -1;
options->log_level = SYSLOG_LEVEL_NOT_SET;
options->preferred_authentications = NULL;
options->bind_address = NULL;
options->smartcard_device = NULL;
options->enable_ssh_keysign = - 1;
options->no_host_authentication_for_localhost = - 1;
options->identities_only = - 1;
options->rekey_limit = - 1;
options->verify_host_key_dns = -1;
options->server_alive_interval = -1;
options->server_alive_count_max = -1;
options->num_send_env = 0;
options->control_path = NULL;
options->control_master = -1;
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->use_roaming = -1;
options->visual_host_key = -1;
options->zero_knowledge_password_authentication = -1;
}
/*
* Called after processing other sources of option data, this fills those
* options for which no value has been specified with their default values.
*/
void
fill_default_options(Options * options)
{
int len;
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->exit_on_forward_failure == -1)
options->exit_on_forward_failure = 0;
if (options->xauth_location == NULL)
options->xauth_location = _PATH_XAUTH;
if (options->gateway_ports == -1)
options->gateway_ports = 0;
if (options->use_privileged_port == -1)
options->use_privileged_port = 0;
if (options->rsa_authentication == -1)
options->rsa_authentication = 1;
if (options->pubkey_authentication == -1)
options->pubkey_authentication = 1;
if (options->challenge_response_authentication == -1)
options->challenge_response_authentication = 1;
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->rhosts_rsa_authentication == -1)
options->rhosts_rsa_authentication = 0;
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 = 1;
if (options->strict_host_key_checking == -1)
options->strict_host_key_checking = 2; /* 2 is default */
if (options->compression == -1)
options->compression = 0;
if (options->tcp_keep_alive == -1)
options->tcp_keep_alive = 1;
if (options->compression_level == -1)
options->compression_level = 6;
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;
/* Selected in ssh_login(). */
if (options->cipher == -1)
options->cipher = SSH_CIPHER_NOT_SET;
/* options->ciphers, default set in myproposals.h */
/* options->macs, default set in myproposals.h */
/* options->hostkeyalgorithms, default set in myproposals.h */
if (options->protocol == SSH_PROTO_UNKNOWN)
options->protocol = SSH_PROTO_1|SSH_PROTO_2;
if (options->num_identity_files == 0) {
if (options->protocol & SSH_PROTO_1) {
len = 2 + strlen(_PATH_SSH_CLIENT_IDENTITY) + 1;
options->identity_files[options->num_identity_files] =
xmalloc(len);
snprintf(options->identity_files[options->num_identity_files++],
len, "~/%.100s", _PATH_SSH_CLIENT_IDENTITY);
}
if (options->protocol & SSH_PROTO_2) {
len = 2 + strlen(_PATH_SSH_CLIENT_ID_RSA) + 1;
options->identity_files[options->num_identity_files] =
xmalloc(len);
snprintf(options->identity_files[options->num_identity_files++],
len, "~/%.100s", _PATH_SSH_CLIENT_ID_RSA);
len = 2 + strlen(_PATH_SSH_CLIENT_ID_DSA) + 1;
options->identity_files[options->num_identity_files] =
xmalloc(len);
snprintf(options->identity_files[options->num_identity_files++],
len, "~/%.100s", _PATH_SSH_CLIENT_ID_DSA);
}
}
if (options->escape_char == -1)
options->escape_char = '~';
if (options->system_hostfile == NULL)
options->system_hostfile = _PATH_SSH_SYSTEM_HOSTFILE;
if (options->user_hostfile == NULL)
options->user_hostfile = _PATH_SSH_USER_HOSTFILE;
if (options->system_hostfile2 == NULL)
options->system_hostfile2 = _PATH_SSH_SYSTEM_HOSTFILE2;
if (options->user_hostfile2 == NULL)
options->user_hostfile2 = _PATH_SSH_USER_HOSTFILE2;
if (options->log_level == SYSLOG_LEVEL_NOT_SET)
options->log_level = SYSLOG_LEVEL_INFO;
if (options->clear_forwardings == 1)
clear_forwardings(options);
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->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->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->use_roaming == -1)
options->use_roaming = 1;
if (options->visual_host_key == -1)
options->visual_host_key = 0;
if (options->zero_knowledge_password_authentication == -1)
options->zero_knowledge_password_authentication = 0;
/* options->local_command should not be set by default */
/* options->proxy_command should not be set by default */
/* 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 */
}
/*
* parse_forward
* parses a string containing a port forwarding specification of the form:
* dynamicfwd == 0
* [listenhost:]listenport:connecthost:connectport
* dynamicfwd == 1
* [listenhost:]listenport
* returns number of arguments parsed or zero on error
*/
int
parse_forward(Forward *fwd, const char *fwdspec, int dynamicfwd, int remotefwd)
{
int i;
char *p, *cp, *fwdarg[4];
memset(fwd, '\0', sizeof(*fwd));
cp = p = xstrdup(fwdspec);
/* skip leading spaces */
while (isspace(*cp))
cp++;
for (i = 0; i < 4; ++i)
if ((fwdarg[i] = hpdelim(&cp)) == NULL)
break;
/* Check for trailing garbage */
if (cp != NULL)
i = 0; /* failure */
switch (i) {
case 1:
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdarg[0]);
fwd->connect_host = xstrdup("socks");
break;
case 2:
fwd->listen_host = xstrdup(cleanhostname(fwdarg[0]));
fwd->listen_port = a2port(fwdarg[1]);
fwd->connect_host = xstrdup("socks");
break;
case 3:
fwd->listen_host = NULL;
fwd->listen_port = a2port(fwdarg[0]);
fwd->connect_host = xstrdup(cleanhostname(fwdarg[1]));
fwd->connect_port = a2port(fwdarg[2]);
break;
case 4:
fwd->listen_host = xstrdup(cleanhostname(fwdarg[0]));
fwd->listen_port = a2port(fwdarg[1]);
fwd->connect_host = xstrdup(cleanhostname(fwdarg[2]));
fwd->connect_port = a2port(fwdarg[3]);
break;
default:
i = 0; /* failure */
}
xfree(p);
if (dynamicfwd) {
if (!(i == 1 || i == 2))
goto fail_free;
} else {
if (!(i == 3 || i == 4))
goto fail_free;
if (fwd->connect_port <= 0)
goto fail_free;
}
if (fwd->listen_port < 0 || (!remotefwd && fwd->listen_port == 0))
goto fail_free;
if (fwd->connect_host != NULL &&
strlen(fwd->connect_host) >= NI_MAXHOST)
goto fail_free;
if (fwd->listen_host != NULL &&
strlen(fwd->listen_host) >= NI_MAXHOST)
goto fail_free;
return (i);
fail_free:
if (fwd->connect_host != NULL) {
xfree(fwd->connect_host);
fwd->connect_host = NULL;
}
if (fwd->listen_host != NULL) {
xfree(fwd->listen_host);
fwd->listen_host = NULL;
}
return (0);
}