freebsd-dev/crypto/openssh/servconf.c
Assar Westerlund cb96ab3672 Add code for being compatible with ssh.com's krb5 authentication.
It is done by using the same ssh messages for v4 and v5 authentication
(since the ssh.com does not now anything about v4) and looking at the
contents after unpacking it to see if it is v4 or v5.
Based on code from Björn Grönvall <bg@sics.se>

PR:		misc/20504
2001-03-04 02:22:04 +00:00

756 lines
21 KiB
C

/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* 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"
RCSID("$OpenBSD: servconf.c,v 1.53 2000/10/14 12:12:09 markus Exp $");
RCSID("$FreeBSD$");
#include "ssh.h"
#include "servconf.h"
#include "xmalloc.h"
#include "compat.h"
/* add listen address */
void add_listen_addr(ServerOptions *options, char *addr);
/* Initializes the server options to their default values. */
void
initialize_server_options(ServerOptions *options)
{
memset(options, 0, sizeof(*options));
options->num_ports = 0;
options->ports_from_cmdline = 0;
options->listen_addrs = NULL;
options->host_key_file = NULL;
options->host_dsa_key_file = NULL;
options->pid_file = NULL;
options->server_key_bits = -1;
options->login_grace_time = -1;
options->key_regeneration_time = -1;
options->permit_root_login = -1;
options->ignore_rhosts = -1;
options->ignore_user_known_hosts = -1;
options->print_motd = -1;
options->check_mail = -1;
options->x11_forwarding = -1;
options->x11_display_offset = -1;
options->xauth_location = NULL;
options->strict_modes = -1;
options->keepalives = -1;
options->log_facility = (SyslogFacility) - 1;
options->log_level = (LogLevel) - 1;
options->rhosts_authentication = -1;
options->rhosts_rsa_authentication = -1;
options->rsa_authentication = -1;
options->dsa_authentication = -1;
#if defined(KRB4) || defined(KRB5)
options->kerberos_authentication = -1;
#endif
#ifdef KRB4
options->krb4_or_local_passwd = -1;
options->krb4_ticket_cleanup = -1;
#endif
#ifdef KRB5
options->krb5_tgt_passing = -1;
#endif /* KRB5 */
#ifdef AFS
options->krb4_tgt_passing = -1;
options->afs_token_passing = -1;
#endif
options->password_authentication = -1;
options->kbd_interactive_authentication = -1;
#ifdef SKEY
options->skey_authentication = -1;
#endif
options->permit_empty_passwd = -1;
options->use_login = -1;
options->allow_tcp_forwarding = -1;
options->num_allow_users = 0;
options->num_deny_users = 0;
options->num_allow_groups = 0;
options->num_deny_groups = 0;
options->ciphers = NULL;
options->protocol = SSH_PROTO_UNKNOWN;
options->gateway_ports = -1;
options->connections_per_period = 0;
options->connections_period = 0;
options->num_subsystems = 0;
options->max_startups_begin = -1;
options->max_startups_rate = -1;
options->max_startups = -1;
}
void
fill_default_server_options(ServerOptions *options)
{
if (options->num_ports == 0)
options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
if (options->listen_addrs == NULL)
add_listen_addr(options, NULL);
if (options->host_key_file == NULL)
options->host_key_file = HOST_KEY_FILE;
if (options->host_dsa_key_file == NULL)
options->host_dsa_key_file = HOST_DSA_KEY_FILE;
if (options->pid_file == NULL)
options->pid_file = SSH_DAEMON_PID_FILE;
if (options->server_key_bits == -1)
options->server_key_bits = 768;
if (options->login_grace_time == -1)
options->login_grace_time = 120;
if (options->key_regeneration_time == -1)
options->key_regeneration_time = 3600;
if (options->permit_root_login == -1)
options->permit_root_login = 0; /* no */
if (options->ignore_rhosts == -1)
options->ignore_rhosts = 1;
if (options->ignore_user_known_hosts == -1)
options->ignore_user_known_hosts = 0;
if (options->check_mail == -1)
options->check_mail = 1;
if (options->print_motd == -1)
options->print_motd = 1;
if (options->x11_forwarding == -1)
options->x11_forwarding = 1;
if (options->x11_display_offset == -1)
options->x11_display_offset = 10;
#ifdef XAUTH_PATH
if (options->xauth_location == NULL)
options->xauth_location = XAUTH_PATH;
#endif /* XAUTH_PATH */
if (options->strict_modes == -1)
options->strict_modes = 1;
if (options->keepalives == -1)
options->keepalives = 1;
if (options->log_facility == (SyslogFacility) (-1))
options->log_facility = SYSLOG_FACILITY_AUTH;
if (options->log_level == (LogLevel) (-1))
options->log_level = SYSLOG_LEVEL_INFO;
if (options->rhosts_authentication == -1)
options->rhosts_authentication = 0;
if (options->rhosts_rsa_authentication == -1)
options->rhosts_rsa_authentication = 0;
if (options->rsa_authentication == -1)
options->rsa_authentication = 1;
if (options->dsa_authentication == -1)
options->dsa_authentication = 1;
#if defined(KRB4) && defined(KRB5)
if (options->kerberos_authentication == -1)
options->kerberos_authentication =
(access(KEYFILE, R_OK) == 0) || (access(krb5_defkeyname, R_OK) == 0);
#elif defined(KRB4)
if (options->kerberos_authentication == -1)
options->kerberos_authentication = (access(KEYFILE, R_OK) == 0);
#elif defined(KRB5)
if (options->kerberos_authentication == -1)
options->kerberos_authentication = (access(krb5_defkeyname, R_OK) == 0);
#endif
#ifdef KRB4
if (options->krb4_or_local_passwd == -1)
options->krb4_or_local_passwd = 1;
if (options->krb4_ticket_cleanup == -1)
options->krb4_ticket_cleanup = 1;
#endif /* KRB4 */
#ifdef KRB5
if (options->krb5_tgt_passing == -1)
options->krb5_tgt_passing = 1;
#endif /* KRB5 */
#ifdef AFS
if (options->krb4_tgt_passing == -1)
options->krb4_tgt_passing = 0;
if (options->afs_token_passing == -1)
options->afs_token_passing = k_hasafs();
#endif /* AFS */
if (options->password_authentication == -1)
options->password_authentication = 1;
if (options->kbd_interactive_authentication == -1)
options->kbd_interactive_authentication = 0;
#ifdef SKEY
if (options->skey_authentication == -1)
options->skey_authentication = 1;
#endif
if (options->permit_empty_passwd == -1)
options->permit_empty_passwd = 0;
if (options->use_login == -1)
options->use_login = 0;
if (options->allow_tcp_forwarding == -1)
options->allow_tcp_forwarding = 1;
if (options->protocol == SSH_PROTO_UNKNOWN)
options->protocol = SSH_PROTO_1|SSH_PROTO_2;
if (options->gateway_ports == -1)
options->gateway_ports = 0;
if (options->max_startups == -1)
options->max_startups = 10;
if (options->max_startups_rate == -1)
options->max_startups_rate = 100; /* 100% */
if (options->max_startups_begin == -1)
options->max_startups_begin = options->max_startups;
}
/* Keyword tokens. */
typedef enum {
sBadOption, /* == unknown option */
sPort, sHostKeyFile, sServerKeyBits, sLoginGraceTime, sKeyRegenerationTime,
sPermitRootLogin, sLogFacility, sLogLevel,
sRhostsAuthentication, sRhostsRSAAuthentication, sRSAAuthentication,
#if defined(KRB4) || defined(KRB5)
sKerberosAuthentication,
#endif
#ifdef KRB4
sKrb4OrLocalPasswd, sKrb4TicketCleanup,
#endif
#ifdef KRB5
sKrb5TgtPassing,
#endif /* KRB5 */
#ifdef AFS
sKrb4TgtPassing, sAFSTokenPassing,
#endif
#ifdef SKEY
sSkeyAuthentication,
#endif
sPasswordAuthentication, sKbdInteractiveAuthentication, sListenAddress,
sPrintMotd, sIgnoreRhosts, sX11Forwarding, sX11DisplayOffset,
sStrictModes, sEmptyPasswd, sRandomSeedFile, sKeepAlives, sCheckMail,
sUseLogin, sAllowTcpForwarding,
sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
sIgnoreUserKnownHosts, sHostDSAKeyFile, sCiphers, sProtocol, sPidFile,
sGatewayPorts, sDSAAuthentication, sConnectionsPerPeriod, sXAuthLocation,
sSubsystem, sMaxStartups
} ServerOpCodes;
/* Textual representation of the tokens. */
static struct {
const char *name;
ServerOpCodes opcode;
} keywords[] = {
{ "port", sPort },
{ "hostkey", sHostKeyFile },
{ "hostdsakey", sHostDSAKeyFile },
{ "pidfile", sPidFile },
{ "serverkeybits", sServerKeyBits },
{ "logingracetime", sLoginGraceTime },
{ "keyregenerationinterval", sKeyRegenerationTime },
{ "permitrootlogin", sPermitRootLogin },
{ "syslogfacility", sLogFacility },
{ "loglevel", sLogLevel },
{ "rhostsauthentication", sRhostsAuthentication },
{ "rhostsrsaauthentication", sRhostsRSAAuthentication },
{ "rsaauthentication", sRSAAuthentication },
{ "dsaauthentication", sDSAAuthentication },
#if defined(KRB4) || defined(KRB5)
{ "kerberosauthentication", sKerberosAuthentication },
#endif
#ifdef KRB4
{ "kerberos4orlocalpasswd", sKrb4OrLocalPasswd },
{ "kerberos4ticketcleanup", sKrb4TicketCleanup },
#endif
#ifdef KRB5
{ "kerberos5tgtpassing", sKrb5TgtPassing },
#endif /* KRB5 */
#ifdef AFS
{ "kerberos4tgtpassing", sKrb4TgtPassing },
{ "afstokenpassing", sAFSTokenPassing },
#endif
{ "passwordauthentication", sPasswordAuthentication },
{ "kbdinteractiveauthentication", sKbdInteractiveAuthentication },
#ifdef SKEY
{ "skeyauthentication", sSkeyAuthentication },
#endif
{ "checkmail", sCheckMail },
{ "listenaddress", sListenAddress },
{ "printmotd", sPrintMotd },
{ "ignorerhosts", sIgnoreRhosts },
{ "ignoreuserknownhosts", sIgnoreUserKnownHosts },
{ "x11forwarding", sX11Forwarding },
{ "x11displayoffset", sX11DisplayOffset },
{ "xauthlocation", sXAuthLocation },
{ "strictmodes", sStrictModes },
{ "permitemptypasswords", sEmptyPasswd },
{ "uselogin", sUseLogin },
{ "randomseed", sRandomSeedFile },
{ "keepalive", sKeepAlives },
{ "allowtcpforwarding", sAllowTcpForwarding },
{ "allowusers", sAllowUsers },
{ "denyusers", sDenyUsers },
{ "allowgroups", sAllowGroups },
{ "denygroups", sDenyGroups },
{ "ciphers", sCiphers },
{ "protocol", sProtocol },
{ "gatewayports", sGatewayPorts },
{ "connectionsperperiod", sConnectionsPerPeriod },
{ "subsystem", sSubsystem },
{ "maxstartups", sMaxStartups },
{ NULL, 0 }
};
/*
* Returns the number of the token pointed to by cp of length len. Never
* returns if the token is not known.
*/
static ServerOpCodes
parse_token(const char *cp, const char *filename,
int linenum)
{
unsigned int i;
for (i = 0; keywords[i].name; i++)
if (strcasecmp(cp, keywords[i].name) == 0)
return keywords[i].opcode;
fprintf(stderr, "%s: line %d: Bad configuration option: %s\n",
filename, linenum, cp);
return sBadOption;
}
/*
* add listen address
*/
void
add_listen_addr(ServerOptions *options, char *addr)
{
extern int IPv4or6;
struct addrinfo hints, *ai, *aitop;
char strport[NI_MAXSERV];
int gaierr;
int i;
if (options->num_ports == 0)
options->ports[options->num_ports++] = SSH_DEFAULT_PORT;
for (i = 0; i < options->num_ports; i++) {
memset(&hints, 0, sizeof(hints));
hints.ai_family = IPv4or6;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = (addr == NULL) ? AI_PASSIVE : 0;
snprintf(strport, sizeof strport, "%d", options->ports[i]);
if ((gaierr = getaddrinfo(addr, strport, &hints, &aitop)) != 0)
fatal("bad addr or host: %s (%s)\n",
addr ? addr : "<NULL>",
gai_strerror(gaierr));
for (ai = aitop; ai->ai_next; ai = ai->ai_next)
;
ai->ai_next = options->listen_addrs;
options->listen_addrs = aitop;
}
}
/* Reads the server configuration file. */
void
read_server_config(ServerOptions *options, const char *filename)
{
FILE *f;
char line[1024];
char *cp, **charptr, *arg;
int linenum, *intptr, value;
int bad_options = 0;
ServerOpCodes opcode;
int i;
f = fopen(filename, "r");
if (!f) {
perror(filename);
exit(1);
}
linenum = 0;
while (fgets(line, sizeof(line), f)) {
linenum++;
cp = line;
arg = strdelim(&cp);
/* Ignore leading whitespace */
if (*arg == '\0')
arg = strdelim(&cp);
if (!*arg || *arg == '#')
continue;
opcode = parse_token(arg, filename, linenum);
switch (opcode) {
case sBadOption:
bad_options++;
continue;
case sPort:
/* ignore ports from configfile if cmdline specifies ports */
if (options->ports_from_cmdline)
continue;
if (options->listen_addrs != NULL)
fatal("%s line %d: ports must be specified before "
"ListenAdress.\n", filename, linenum);
if (options->num_ports >= MAX_PORTS)
fatal("%s line %d: too many ports.\n",
filename, linenum);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing port number.\n",
filename, linenum);
options->ports[options->num_ports++] = atoi(arg);
break;
case sServerKeyBits:
intptr = &options->server_key_bits;
parse_int:
arg = strdelim(&cp);
if (!arg || *arg == '\0') {
fprintf(stderr, "%s line %d: missing integer value.\n",
filename, linenum);
exit(1);
}
value = atoi(arg);
if (value == 0) {
fprintf(stderr, "%s line %d: invalid integer value.\n",
filename, linenum);
exit(1);
}
if (*intptr == -1)
*intptr = value;
break;
case sLoginGraceTime:
intptr = &options->login_grace_time;
goto parse_int;
case sKeyRegenerationTime:
intptr = &options->key_regeneration_time;
goto parse_int;
case sListenAddress:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: missing inet addr.\n",
filename, linenum);
add_listen_addr(options, arg);
break;
case sHostKeyFile:
case sHostDSAKeyFile:
charptr = (opcode == sHostKeyFile ) ?
&options->host_key_file : &options->host_dsa_key_file;
parse_filename:
arg = strdelim(&cp);
if (!arg || *arg == '\0') {
fprintf(stderr, "%s line %d: missing file name.\n",
filename, linenum);
exit(1);
}
if (*charptr == NULL)
*charptr = tilde_expand_filename(arg, getuid());
break;
case sPidFile:
charptr = &options->pid_file;
goto parse_filename;
case sRandomSeedFile:
fprintf(stderr, "%s line %d: \"randomseed\" option is obsolete.\n",
filename, linenum);
arg = strdelim(&cp);
break;
case sPermitRootLogin:
intptr = &options->permit_root_login;
arg = strdelim(&cp);
if (!arg || *arg == '\0') {
fprintf(stderr, "%s line %d: missing yes/without-password/no argument.\n",
filename, linenum);
exit(1);
}
if (strcmp(arg, "without-password") == 0)
value = 2;
else if (strcmp(arg, "yes") == 0)
value = 1;
else if (strcmp(arg, "no") == 0)
value = 0;
else {
fprintf(stderr, "%s line %d: Bad yes/without-password/no argument: %s\n",
filename, linenum, arg);
exit(1);
}
if (*intptr == -1)
*intptr = value;
break;
case sIgnoreRhosts:
intptr = &options->ignore_rhosts;
parse_flag:
arg = strdelim(&cp);
if (!arg || *arg == '\0') {
fprintf(stderr, "%s line %d: missing yes/no argument.\n",
filename, linenum);
exit(1);
}
if (strcmp(arg, "yes") == 0)
value = 1;
else if (strcmp(arg, "no") == 0)
value = 0;
else {
fprintf(stderr, "%s line %d: Bad yes/no argument: %s\n",
filename, linenum, arg);
exit(1);
}
if (*intptr == -1)
*intptr = value;
break;
case sIgnoreUserKnownHosts:
intptr = &options->ignore_user_known_hosts;
goto parse_flag;
case sRhostsAuthentication:
intptr = &options->rhosts_authentication;
goto parse_flag;
case sRhostsRSAAuthentication:
intptr = &options->rhosts_rsa_authentication;
goto parse_flag;
case sRSAAuthentication:
intptr = &options->rsa_authentication;
goto parse_flag;
case sDSAAuthentication:
intptr = &options->dsa_authentication;
goto parse_flag;
#if defined(KRB4) || defined(KRB5)
case sKerberosAuthentication:
intptr = &options->kerberos_authentication;
goto parse_flag;
#endif
#ifdef KRB4
case sKrb4OrLocalPasswd:
intptr = &options->krb4_or_local_passwd;
goto parse_flag;
case sKrb4TicketCleanup:
intptr = &options->krb4_ticket_cleanup;
goto parse_flag;
#endif
#ifdef KRB5
case sKrb5TgtPassing:
intptr = &options->krb5_tgt_passing;
goto parse_flag;
#endif /* KRB5 */
#ifdef AFS
case sKrb4TgtPassing:
intptr = &options->krb4_tgt_passing;
goto parse_flag;
case sAFSTokenPassing:
intptr = &options->afs_token_passing;
goto parse_flag;
#endif
case sPasswordAuthentication:
intptr = &options->password_authentication;
goto parse_flag;
case sKbdInteractiveAuthentication:
intptr = &options->kbd_interactive_authentication;
goto parse_flag;
case sCheckMail:
intptr = &options->check_mail;
goto parse_flag;
#ifdef SKEY
case sSkeyAuthentication:
intptr = &options->skey_authentication;
goto parse_flag;
#endif
case sPrintMotd:
intptr = &options->print_motd;
goto parse_flag;
case sX11Forwarding:
intptr = &options->x11_forwarding;
goto parse_flag;
case sX11DisplayOffset:
intptr = &options->x11_display_offset;
goto parse_int;
case sXAuthLocation:
charptr = &options->xauth_location;
goto parse_filename;
case sStrictModes:
intptr = &options->strict_modes;
goto parse_flag;
case sKeepAlives:
intptr = &options->keepalives;
goto parse_flag;
case sEmptyPasswd:
intptr = &options->permit_empty_passwd;
goto parse_flag;
case sUseLogin:
intptr = &options->use_login;
goto parse_flag;
case sGatewayPorts:
intptr = &options->gateway_ports;
goto parse_flag;
case sLogFacility:
intptr = (int *) &options->log_facility;
arg = strdelim(&cp);
value = log_facility_number(arg);
if (value == (SyslogFacility) - 1)
fatal("%.200s line %d: unsupported log facility '%s'\n",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == -1)
*intptr = (SyslogFacility) value;
break;
case sLogLevel:
intptr = (int *) &options->log_level;
arg = strdelim(&cp);
value = log_level_number(arg);
if (value == (LogLevel) - 1)
fatal("%.200s line %d: unsupported log level '%s'\n",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == -1)
*intptr = (LogLevel) value;
break;
case sAllowTcpForwarding:
intptr = &options->allow_tcp_forwarding;
goto parse_flag;
case sAllowUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_users >= MAX_ALLOW_USERS)
fatal("%.200s line %d: too many allow users.\n",
filename, linenum);
options->allow_users[options->num_allow_users++] = xstrdup(arg);
}
break;
case sDenyUsers:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_users >= MAX_DENY_USERS)
fatal("%.200s line %d: too many deny users.\n",
filename, linenum);
options->deny_users[options->num_deny_users++] = xstrdup(arg);
}
break;
case sAllowGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_allow_groups >= MAX_ALLOW_GROUPS)
fatal("%.200s line %d: too many allow groups.\n",
filename, linenum);
options->allow_groups[options->num_allow_groups++] = xstrdup(arg);
}
break;
case sDenyGroups:
while ((arg = strdelim(&cp)) && *arg != '\0') {
if (options->num_deny_groups >= MAX_DENY_GROUPS)
fatal("%.200s line %d: too many deny groups.\n",
filename, linenum);
options->deny_groups[options->num_deny_groups++] = xstrdup(arg);
}
break;
case sCiphers:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
if (!ciphers_valid(arg))
fatal("%s line %d: Bad SSH2 cipher spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (options->ciphers == NULL)
options->ciphers = xstrdup(arg);
break;
case sProtocol:
intptr = &options->protocol;
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing argument.", filename, linenum);
value = proto_spec(arg);
if (value == SSH_PROTO_UNKNOWN)
fatal("%s line %d: Bad protocol spec '%s'.",
filename, linenum, arg ? arg : "<NONE>");
if (*intptr == SSH_PROTO_UNKNOWN)
*intptr = value;
break;
case sConnectionsPerPeriod:
(void)strdelim(&cp);
error("ConnectionsPerPeriod has been deprecated!");
break;
case sSubsystem:
if(options->num_subsystems >= MAX_SUBSYSTEMS) {
fatal("%s line %d: too many subsystems defined.",
filename, linenum);
}
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem name.",
filename, linenum);
for (i = 0; i < options->num_subsystems; i++)
if(strcmp(arg, options->subsystem_name[i]) == 0)
fatal("%s line %d: Subsystem '%s' already defined.",
filename, linenum, arg);
options->subsystem_name[options->num_subsystems] = xstrdup(arg);
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing subsystem command.",
filename, linenum);
options->subsystem_command[options->num_subsystems] = xstrdup(arg);
options->num_subsystems++;
break;
case sMaxStartups:
arg = strdelim(&cp);
if (!arg || *arg == '\0')
fatal("%s line %d: Missing MaxStartups spec.",
filename, linenum);
if (sscanf(arg, "%d:%d:%d",
&options->max_startups_begin,
&options->max_startups_rate,
&options->max_startups) == 3) {
if (options->max_startups_begin >
options->max_startups ||
options->max_startups_rate > 100 ||
options->max_startups_rate < 1)
fatal("%s line %d: Illegal MaxStartups spec.",
filename, linenum);
break;
}
intptr = &options->max_startups;
goto parse_int;
default:
fatal("%.200s line %d: Missing handler for opcode %s (%d)\n",
filename, linenum,arg, opcode);
}
if ((arg = strdelim(&cp)) != NULL && *arg != '\0') {
fprintf(stderr,
"%s line %d: garbage at end of line; \"%.200s\".\n",
filename, linenum, arg);
exit(1);
}
}
fclose(f);
if (bad_options > 0) {
fatal("%.200s: terminating, %d bad configuration options\n",
filename, bad_options);
}
}