1gnutls-serv(1) User Commands gnutls-serv(1)
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6 gnutls-serv - GnuTLS server
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9 gnutls-serv [-flags] [-flag [value]] [--option-name[[=| ]value]]
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11 All arguments must be options.
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14 Server program that listens to incoming TLS connections.
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18 -d num, --debug=num
19 Enable debugging. This option takes an integer number as its
20 argument. The value of num is constrained to being:
21 in the range 0 through 9999
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23 Specifies the debug level.
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25 --sni-hostname=str
26 Server's hostname for server name extension.
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28 Server name of type host_name that the server will recognise as
29 its own. If the server receives client hello with different
30 name, it will send a warning-level unrecognized_name alert.
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32 --sni-hostname-fatal
33 Send fatal alert on sni-hostname mismatch.
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36 --alpn=str
37 Specify ALPN protocol to be enabled by the server. This option
38 may appear an unlimited number of times.
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40 Specify the (textual) ALPN protocol for the server to use.
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42 --alpn-fatal
43 Send fatal alert on non-matching ALPN name.
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46 --noticket
47 Don't accept session tickets.
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50 --earlydata
51 Accept early data.
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54 --maxearlydata=num
55 The maximum early data size to accept. This option takes an in‐
56 teger number as its argument. The value of num is constrained
57 to being:
58 in the range 1 through 2147483648
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61 --nocookie
62 Don't require cookie on DTLS sessions.
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65 -g, --generate
66 Generate Diffie-Hellman parameters.
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69 -q, --quiet
70 Suppress some messages.
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73 --nodb Do not use a resumption database.
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76 --http Act as an HTTP server.
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79 --echo Act as an Echo server.
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82 --crlf Do not replace CRLF by LF in Echo server mode.
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85 -u, --udp
86 Use DTLS (datagram TLS) over UDP.
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89 --mtu=num
90 Set MTU for datagram TLS. This option takes an integer number
91 as its argument. The value of num is constrained to being:
92 in the range 0 through 17000
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95 --srtp-profiles=str
96 Offer SRTP profiles.
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99 -a, --disable-client-cert
100 Do not request a client certificate. This option must not ap‐
101 pear in combination with any of the following options: require-
102 client-cert.
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105 -r, --require-client-cert
106 Require a client certificate.
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108 This option before 3.6.0 used to imply --verify-client-cert.
109 Since 3.6.0 it will no longer verify the certificate by default.
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111 --verify-client-cert
112 If a client certificate is sent then verify it.
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114 Do not require, but if a client certificate is sent then verify
115 it and close the connection if invalid.
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117 --compress-cert=str
118 Compress certificate. This option may appear an unlimited num‐
119 ber of times.
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121 This option sets a supported compression method for certificate
122 compression.
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124 -b, --heartbeat
125 Activate heartbeat support.
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127 Regularly ping client via heartbeat extension messages
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129 --x509fmtder
130 Use DER format for certificates to read from.
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133 --priority=str
134 Priorities string.
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136 TLS algorithms and protocols to enable. You can use predefined
137 sets of ciphersuites such as PERFORMANCE, NORMAL, SECURE128, SE‐
138 CURE256. The default is NORMAL.
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140 Check the GnuTLS manual on section “Priority strings” for
141 more information on allowed keywords
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143 --dhparams=file
144 DH params file to use.
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147 --x509cafile=str
148 Certificate file or PKCS #11 URL to use.
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151 --x509crlfile=file
152 CRL file to use.
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155 --pgpkeyfile=file
156 PGP Key file to use.
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159 NOTE: THIS OPTION IS DEPRECATED
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161 --x509keyfile=str
162 X.509 key file or PKCS #11 URL to use. This option may appear
163 an unlimited number of times.
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165 Specify the private key file or URI to use; it must correspond
166 to the certificate specified in --x509certfile. Multiple keys
167 and certificates can be specified with this option and in that
168 case each occurrence of keyfile must be followed by the corre‐
169 sponding x509certfile or vice-versa.
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171 --x509certfile=str
172 X.509 Certificate file or PKCS #11 URL to use. This option may
173 appear an unlimited number of times.
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175 Specify the certificate file or URI to use; it must correspond
176 to the key specified in --x509keyfile. Multiple keys and cer‐
177 tificates can be specified with this option and in that case
178 each occurrence of keyfile must be followed by the corresponding
179 x509certfile or vice-versa.
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181 --x509dsakeyfile
182 This is an alias for the --x509keyfile option.
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184 NOTE: THIS OPTION IS DEPRECATED
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186 --x509dsacertfile
187 This is an alias for the --x509certfile option.
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189 NOTE: THIS OPTION IS DEPRECATED
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191 --x509ecckeyfile
192 This is an alias for the --x509keyfile option.
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194 NOTE: THIS OPTION IS DEPRECATED
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196 --x509ecccertfile
197 This is an alias for the --x509certfile option.
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199 NOTE: THIS OPTION IS DEPRECATED
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201 --rawpkkeyfile=str
202 Private key file (PKCS #8 or PKCS #12) or PKCS #11 URL to use.
203 This option may appear an unlimited number of times.
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205 Specify the private key file or URI to use; it must correspond
206 to the raw public-key specified in --rawpkfile. Multiple key
207 pairs can be specified with this option and in that case each
208 occurrence of keyfile must be followed by the corresponding raw‐
209 pkfile or vice-versa.
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211 In order to instruct the application to negotiate raw public
212 keys one must enable the respective certificate types via the
213 priority strings (i.e. CTYPE-CLI-* and CTYPE-SRV-* flags).
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215 Check the GnuTLS manual on section “Priority strings” for
216 more information on how to set certificate types.
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218 --rawpkfile=str
219 Raw public-key file to use. This option may appear an unlimited
220 number of times. This option must appear in combination with
221 the following options: rawpkkeyfile.
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223 Specify the raw public-key file to use; it must correspond to
224 the private key specified in --rawpkkeyfile. Multiple key pairs
225 can be specified with this option and in that case each occur‐
226 rence of keyfile must be followed by the corresponding rawpkfile
227 or vice-versa.
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229 In order to instruct the application to negotiate raw public
230 keys one must enable the respective certificate types via the
231 priority strings (i.e. CTYPE-CLI-* and CTYPE-SRV-* flags).
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233 Check the GnuTLS manual on section “Priority strings” for
234 more information on how to set certificate types.
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236 --srppasswd=file
237 SRP password file to use.
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240 --srppasswdconf=file
241 SRP password configuration file to use.
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244 --pskpasswd=file
245 PSK password file to use.
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248 --pskhint=str
249 PSK identity hint to use.
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252 --ocsp-response=str
253 The OCSP response to send to client. This option may appear an
254 unlimited number of times.
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256 If the client requested an OCSP response, return data from this
257 file to the client.
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259 --ignore-ocsp-response-errors
260 Ignore any errors when setting the OCSP response.
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262 That option instructs gnutls to not attempt to match the pro‐
263 vided OCSP responses with the certificates.
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265 -p num, --port=num
266 The port to connect to. This option takes an integer number as
267 its argument.
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270 -l, --list
271 Print a list of the supported algorithms and modes.
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273 Print a list of the supported algorithms and modes. If a prior‐
274 ity string is given then only the enabled ciphersuites are
275 shown.
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277 --provider=file
278 Specify the PKCS #11 provider library.
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280 This will override the default options in
281 /etc/gnutls/pkcs11.conf
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283 --keymatexport=str
284 Label used for exporting keying material.
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287 --keymatexportsize=num
288 Size of the exported keying material. This option takes an in‐
289 teger number as its argument.
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292 --recordsize=num
293 The maximum record size to advertise. This option takes an in‐
294 teger number as its argument. The value of num is constrained
295 to being:
296 in the range 0 through 16384
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299 --httpdata=file
300 The data used as HTTP response.
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303 -v arg, --version=arg
304 Output version of program and exit. The default mode is `v', a
305 simple version. The `c' mode will print copyright information
306 and `n' will print the full copyright notice.
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308 -h, --help
309 Display usage information and exit.
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311 -!, --more-help
312 Pass the extended usage information through a pager.
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317 Running your own TLS server based on GnuTLS can be useful when debug‐
318 ging clients and/or GnuTLS itself. This section describes how to use
319 gnutls-serv as a simple HTTPS server.
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321 The most basic server can be started as:
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323 gnutls-serv --http --priority "NORMAL:+ANON-ECDH:+ANON-DH"
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325 It will only support anonymous ciphersuites, which many TLS clients
326 refuse to use.
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328 The next step is to add support for X.509. First we generate a CA:
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330 $ certtool --generate-privkey > x509-ca-key.pem
331 $ echo 'cn = GnuTLS test CA' > ca.tmpl
332 $ echo 'ca' >> ca.tmpl
333 $ echo 'cert_signing_key' >> ca.tmpl
334 $ certtool --generate-self-signed --load-privkey x509-ca-key.pem --template ca.tmpl --outfile x509-ca.pem
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336 Then generate a server certificate. Remember to change the dns_name
337 value to the name of your server host, or skip that command to avoid
338 the field.
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340 $ certtool --generate-privkey > x509-server-key.pem
341 $ echo 'organization = GnuTLS test server' > server.tmpl
342 $ echo 'cn = test.gnutls.org' >> server.tmpl
343 $ echo 'tls_www_server' >> server.tmpl
344 $ echo 'encryption_key' >> server.tmpl
345 $ echo 'signing_key' >> server.tmpl
346 $ echo 'dns_name = test.gnutls.org' >> server.tmpl
347 $ certtool --generate-certificate --load-privkey x509-server-key.pem --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem --template server.tmpl --outfile x509-server.pem
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349 For use in the client, you may want to generate a client certificate as
350 well.
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352 $ certtool --generate-privkey > x509-client-key.pem
353 $ echo 'cn = GnuTLS test client' > client.tmpl
354 $ echo 'tls_www_client' >> client.tmpl
355 $ echo 'encryption_key' >> client.tmpl
356 $ echo 'signing_key' >> client.tmpl
357 $ certtool --generate-certificate --load-privkey x509-client-key.pem --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem --template client.tmpl --outfile x509-client.pem
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359 To be able to import the client key/certificate into some applications,
360 you will need to convert them into a PKCS#12 structure. This also en‐
361 crypts the security sensitive key with a password.
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363 $ certtool --to-p12 --load-ca-certificate x509-ca.pem --load-privkey x509-client-key.pem --load-certificate x509-client.pem --outder --outfile x509-client.p12
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365 For icing, we'll create a proxy certificate for the client too.
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367 $ certtool --generate-privkey > x509-proxy-key.pem
368 $ echo 'cn = GnuTLS test client proxy' > proxy.tmpl
369 $ certtool --generate-proxy --load-privkey x509-proxy-key.pem --load-ca-certificate x509-client.pem --load-ca-privkey x509-client-key.pem --load-certificate x509-client.pem --template proxy.tmpl --outfile x509-proxy.pem
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371 Then start the server again:
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373 $ gnutls-serv --http --x509cafile x509-ca.pem --x509keyfile x509-server-key.pem --x509certfile x509-server.pem
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375 Try connecting to the server using your web browser. Note that the
376 server listens to port 5556 by default.
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378 While you are at it, to allow connections using ECDSA, you can also
379 create a ECDSA key and certificate for the server. These credentials
380 will be used in the final example below.
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382 $ certtool --generate-privkey --ecdsa > x509-server-key-ecc.pem
383 $ certtool --generate-certificate --load-privkey x509-server-key-ecc.pem --load-ca-certificate x509-ca.pem --load-ca-privkey x509-ca-key.pem --template server.tmpl --outfile x509-server-ecc.pem
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386 The next step is to add support for SRP authentication. This requires
387 an SRP password file created with srptool. To start the server with
388 SRP support:
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390 gnutls-serv --http --priority NORMAL:+SRP-RSA:+SRP --srppasswdconf srp-tpasswd.conf --srppasswd srp-passwd.txt
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392 Let's also start a server with support for PSK. This would require a
393 password file created with psktool.
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395 gnutls-serv --http --priority NORMAL:+ECDHE-PSK:+PSK --pskpasswd psk-passwd.txt
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397 If you want a server with support for raw public-keys we can also add
398 these credentials. Note however that there is no identity information
399 linked to these keys as is the case with regular x509 certificates. Au‐
400 thentication must be done via different means. Also we need to explic‐
401 itly enable raw public-key certificates via the priority strings.
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403 gnutls-serv --http --priority NORMAL:+CTYPE-CLI-RAWPK:+CTYPE-SRV-RAWPK --rawpkfile srv.rawpk.pem --rawpkkeyfile srv.key.pem
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406 Finally, we start the server with all the earlier parameters and you
407 get this command:
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409 gnutls-serv --http --priority NORMAL:+PSK:+SRP:+CTYPE-CLI-RAWPK:+CTYPE-SRV-RAWPK --x509cafile x509-ca.pem --x509keyfile x509-server-key.pem --x509certfile x509-server.pem --x509keyfile x509-server-key-ecc.pem --x509certfile x509-server-ecc.pem --srppasswdconf srp-tpasswd.conf --srppasswd srp-passwd.txt --pskpasswd psk-passwd.txt --rawpkfile srv.rawpk.pem --rawpkkeyfile srv.key.pem
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412 One of the following exit values will be returned:
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414 0 (EXIT_SUCCESS)
415 Successful program execution.
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417 1 (EXIT_FAILURE)
418 The operation failed or the command syntax was not valid.
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421 gnutls-cli-debug(1), gnutls-cli(1)
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425 Copyright (C) 2020-2021 Free Software Foundation, and others all rights
426 reserved. This program is released under the terms of the GNU General
427 Public License, version 3 or later
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430 Please send bug reports to: bugs@gnutls.org
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4343.7.8 27 Sep 2022 gnutls-serv(1)