readconf.c

OpenSSL Source code for SFTP, SSH, and many others

	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;
		string = xstrdup("");
		while ((arg = strdelim(&s)) != NULL && *arg != '\0') {
			string = xrealloc(string, strlen(string) + strlen(arg) + 2);
			strcat(string, " ");
			strcat(string, arg);
		}
		if (*activep && *charptr == NULL)
			*charptr = string;
		else
			xfree(string);
		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:
		intptr = (int *) &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 && (LogLevel) *intptr == SYSLOG_LEVEL_NOT_SET)
			*intptr = (LogLevel) value;
		break;

	case oLocalForward:
	case oRemoteForward:
		arg = strdelim(&s);
		if (!arg || *arg == '\0')
			fatal("%.200s line %d: Missing port argument.",
			    filename, linenum);
		if ((fwd_port = a2port(arg)) == 0)
			fatal("%.200s line %d: Bad listen port.",
			    filename, linenum);
		arg = strdelim(&s);
		if (!arg || *arg == '\0')
			fatal("%.200s line %d: Missing second argument.",
			    filename, linenum);
		if (sscanf(arg, "%255[^:]:%5[0-9]", buf, sfwd_host_port) != 2 &&
		    sscanf(arg, "%255[^/]/%5[0-9]", buf, sfwd_host_port) != 2)
			fatal("%.200s line %d: Bad forwarding specification.",
			    filename, linenum);
		if ((fwd_host_port = a2port(sfwd_host_port)) == 0)
			fatal("%.200s line %d: Bad forwarding port.",
			    filename, linenum);
		if (*activep) {
			if (opcode == oLocalForward)
				add_local_forward(options, fwd_port, buf,
				    fwd_host_port);
			else if (opcode == oRemoteForward)
				add_remote_forward(options, fwd_port, buf,
				    fwd_host_port);
		}
		break;

	case oDynamicForward:
		arg = strdelim(&s);
		if (!arg || *arg == '\0')
			fatal("%.200s line %d: Missing port argument.",
			    filename, linenum);
		fwd_port = a2port(arg);
		if (fwd_port == 0)
			fatal("%.200s line %d: Badly formatted port number.",
			    filename, linenum);
		if (*activep)
			add_local_forward(options, fwd_port, "socks4", 0);
		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 oDeprecated:
		debug("%s line %d: Deprecated 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)
{
	FILE *f;
	char line[1024];
	int active, linenum;
	int bad_options = 0;

	/* Open the file. */
	f = fopen(filename, "r");
	if (!f)
		return 0;

	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->xauth_location = NULL;
	options->gateway_ports = -1;
	options->use_privileged_port = -1;
	options->rhosts_authentication = -1;
	options->rsa_authentication = -1;
	options->pubkey_authentication = -1;
	options->challenge_response_authentication = -1;
#if defined(KRB4) || defined(KRB5)
	options->kerberos_authentication = -1;
#endif
#if defined(AFS) || defined(KRB5)
	options->kerberos_tgt_passing = -1;
#endif
#ifdef AFS
	options->afs_token_passing = -1;
#endif
	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->keepalives = -1;
	options->compression_level = -1;
	options->port = -1;
	options->connection_attempts = -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->no_host_authentication_for_localhost = - 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->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->rhosts_authentication == -1)
		options->rhosts_authentication = 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 defined(KRB4) || defined(KRB5)
	if (options->kerberos_authentication == -1)
		options->kerberos_authentication = 1;
#endif
#if defined(AFS) || defined(KRB5)
	if (options->kerberos_tgt_passing == -1)
		options->kerberos_tgt_passing = 1;
#endif
#ifdef AFS
	if (options->afs_token_passing == -1)
		options->afs_token_passing = 1;
#endif
	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->keepalives == -1)
		options->keepalives = 1;
	if (options->compression_level == -1)
		options->compression_level = 6;
	if (options->port == -1)
		options->port = 0;	/* Filled in ssh_connect. */
	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;
	/* 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 */
}