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3db935a9 DSH |
1 | =pod |
2 | ||
3 | =head1 NAME | |
4 | ||
1722496f | 5 | SSL_CONF_cmd_value_type, |
3db935a9 DSH |
6 | SSL_CONF_cmd - send configuration command |
7 | ||
8 | =head1 SYNOPSIS | |
9 | ||
10 | #include <openssl/ssl.h> | |
11 | ||
12 | int SSL_CONF_cmd(SSL_CONF_CTX *cctx, const char *cmd, const char *value); | |
ec2f7e56 | 13 | int SSL_CONF_cmd_value_type(SSL_CONF_CTX *cctx, const char *cmd); |
3db935a9 DSH |
14 | |
15 | =head1 DESCRIPTION | |
16 | ||
17 | The function SSL_CONF_cmd() performs configuration operation B<cmd> with | |
18 | optional parameter B<value> on B<ctx>. Its purpose is to simplify application | |
19 | configuration of B<SSL_CTX> or B<SSL> structures by providing a common | |
13cfb043 DSH |
20 | framework for command line options or configuration files. |
21 | ||
ec2f7e56 DSH |
22 | SSL_CONF_cmd_value_type() returns the type of value that B<cmd> refers to. |
23 | ||
13cfb043 DSH |
24 | =head1 SUPPORTED COMMAND LINE COMMANDS |
25 | ||
26 | Currently supported B<cmd> names for command lines (i.e. when the | |
27 | flag B<SSL_CONF_CMDLINE> is set) are listed below. Note: all B<cmd> names | |
4b64e0cb | 28 | are case sensitive. Unless otherwise stated commands can be used by |
13cfb043 DSH |
29 | both clients and servers and the B<value> parameter is not used. The default |
30 | prefix for command line commands is B<-> and that is reflected below. | |
31 | ||
32 | =over 4 | |
33 | ||
34 | =item B<-sigalgs> | |
35 | ||
36 | This sets the supported signature algorithms for TLS v1.2. For clients this | |
37 | value is used directly for the supported signature algorithms extension. For | |
38 | servers it is used to determine which signature algorithms to support. | |
39 | ||
40 | The B<value> argument should be a colon separated list of signature algorithms | |
41 | in order of decreasing preference of the form B<algorithm+hash>. B<algorithm> | |
42 | is one of B<RSA>, B<DSA> or B<ECDSA> and B<hash> is a supported algorithm | |
43 | OID short name such as B<SHA1>, B<SHA224>, B<SHA256>, B<SHA384> of B<SHA512>. | |
44 | Note: algorithm and hash names are case sensitive. | |
45 | ||
46 | If this option is not set then all signature algorithms supported by the | |
47 | OpenSSL library are permissible. | |
48 | ||
49 | =item B<-client_sigalgs> | |
50 | ||
51 | This sets the supported signature algorithms associated with client | |
52 | authentication for TLS v1.2. For servers the value is used in the supported | |
53 | signature algorithms field of a certificate request. For clients it is | |
54 | used to determine which signature algorithm to with the client certificate. | |
55 | If a server does not request a certificate this option has no effect. | |
56 | ||
57 | The syntax of B<value> is identical to B<-sigalgs>. If not set then | |
58 | the value set for B<-sigalgs> will be used instead. | |
59 | ||
47f7cf05 MC |
60 | =item B<-groups> |
61 | ||
62 | This sets the supported groups. For clients, the groups are | |
63 | sent using the supported groups extension. For servers, it is used | |
64 | to determine which group to use. This setting affects groups used for both | |
65 | signatures and key exchange, if applicable. It also affects the preferred | |
66 | key_share sent by a client in a TLSv1.3 compatible connection. | |
67 | ||
68 | The B<value> argument is a colon separated list of groups. The group can be | |
69 | either the B<NIST> name (e.g. B<P-256>), some other commonly used name where | |
70 | applicable (e.g. B<X25519>) or an OpenSSL OID name (e.g B<prime256v1>). Group | |
71 | names are case sensitive. The list should be in order of preference with the | |
72 | most preferred group first. The first listed group will be the one used for a | |
73 | key_share by a TLSv1.3 client. | |
74 | ||
75 | =item B<-curves> | |
76 | ||
77 | This is a synonym for the "-groups" command. | |
78 | ||
79 | ||
13cfb043 DSH |
80 | =item B<-named_curve> |
81 | ||
7946ab33 | 82 | This sets the temporary curve used for ephemeral ECDH modes. Only used by |
13cfb043 DSH |
83 | servers |
84 | ||
85 | The B<value> argument is a curve name or the special value B<auto> which | |
86 | picks an appropriate curve based on client and server preferences. The curve | |
87 | can be either the B<NIST> name (e.g. B<P-256>) or an OpenSSL OID name | |
88 | (e.g B<prime256v1>). Curve names are case sensitive. | |
89 | ||
90 | =item B<-cipher> | |
91 | ||
92 | Sets the cipher suite list to B<value>. Note: syntax checking of B<value> is | |
7946ab33 | 93 | currently not performed unless a B<SSL> or B<SSL_CTX> structure is |
13cfb043 DSH |
94 | associated with B<cctx>. |
95 | ||
ec2f7e56 DSH |
96 | =item B<-cert> |
97 | ||
98 | Attempts to use the file B<value> as the certificate for the appropriate | |
fc1d88f0 RS |
99 | context. It currently uses SSL_CTX_use_certificate_chain_file() if an B<SSL_CTX> |
100 | structure is set or SSL_use_certificate_file() with filetype PEM if an B<SSL> | |
ec2f7e56 DSH |
101 | structure is set. This option is only supported if certificate operations |
102 | are permitted. | |
103 | ||
104 | =item B<-key> | |
105 | ||
106 | Attempts to use the file B<value> as the private key for the appropriate | |
107 | context. This option is only supported if certificate operations | |
108 | are permitted. Note: if no B<-key> option is set then a private key is | |
2011b169 | 109 | not loaded unless the flag B<SSL_CONF_FLAG_REQUIRE_PRIVATE> is set. |
ec2f7e56 | 110 | |
c557f921 DSH |
111 | =item B<-dhparam> |
112 | ||
113 | Attempts to use the file B<value> as the set of temporary DH parameters for | |
114 | the appropriate context. This option is only supported if certificate | |
115 | operations are permitted. | |
116 | ||
c649d10d TS |
117 | =item B<-record_padding> |
118 | ||
119 | Attempts to pad TLS 1.3 records so that they are a multiple of B<value> in | |
120 | length on send. A B<value> of 0 or 1 turns off padding. Otherwise, the | |
121 | B<value> must be >1 or <=16384. | |
122 | ||
db0f35dd TS |
123 | =item B<-no_renegotiation> |
124 | ||
125 | Disables all attempts at renegotiation in TLSv1.2 and earlier, same as setting | |
126 | B<SSL_OP_NO_RENEGOTIATION>. | |
127 | ||
7946ab33 KR |
128 | =item B<-min_protocol>, B<-max_protocol> |
129 | ||
130 | Sets the minimum and maximum supported protocol. | |
57ce7b61 | 131 | Currently supported protocol values are B<SSLv3>, B<TLSv1>, |
869e978c KR |
132 | B<TLSv1.1>, B<TLSv1.2> for TLS and B<DTLSv1>, B<DTLSv1.2> for DTLS, |
133 | and B<None> for no limit. | |
57ce7b61 VD |
134 | If the either bound is not specified then only the other bound applies, |
135 | if specified. | |
136 | To restrict the supported protocol versions use these commands rather | |
137 | than the deprecated alternative commands below. | |
7946ab33 | 138 | |
582a17d6 | 139 | =item B<-no_ssl3>, B<-no_tls1>, B<-no_tls1_1>, B<-no_tls1_2>, B<-no_tls1_3> |
13cfb043 | 140 | |
582a17d6 MC |
141 | Disables protocol support for SSLv3, TLSv1.0, TLSv1.1, TLSv1.2 or TLSv1.3 by |
142 | setting the corresponding options B<SSL_OP_NO_SSLv3>, B<SSL_OP_NO_TLSv1>, | |
143 | B<SSL_OP_NO_TLSv1_1>, B<SSL_OP_NO_TLSv1_2> and B<SSL_OP_NO_TLSv1_3> | |
144 | respectively. These options are deprecated, instead use B<-min_protocol> and | |
145 | B<-max_protocol>. | |
13cfb043 DSH |
146 | |
147 | =item B<-bugs> | |
148 | ||
149 | Various bug workarounds are set, same as setting B<SSL_OP_ALL>. | |
150 | ||
dc5744cb | 151 | =item B<-comp> |
13cfb043 | 152 | |
cc5a9ba4 VD |
153 | Enables support for SSL/TLS compression, same as clearing |
154 | B<SSL_OP_NO_COMPRESSION>. | |
155 | This command was introduced in OpenSSL 1.1.0. | |
156 | As of OpenSSL 1.1.0, compression is off by default. | |
157 | ||
158 | =item B<-no_comp> | |
159 | ||
160 | Disables support for SSL/TLS compression, same as setting | |
161 | B<SSL_OP_NO_COMPRESSION>. | |
162 | As of OpenSSL 1.1.0, compression is off by default. | |
13cfb043 DSH |
163 | |
164 | =item B<-no_ticket> | |
165 | ||
166 | Disables support for session tickets, same as setting B<SSL_OP_NO_TICKET>. | |
167 | ||
168 | =item B<-serverpref> | |
169 | ||
170 | Use server and not client preference order when determining which cipher suite, | |
171 | signature algorithm or elliptic curve to use for an incoming connection. | |
172 | Equivalent to B<SSL_OP_CIPHER_SERVER_PREFERENCE>. Only used by servers. | |
173 | ||
f0ef019d DSH |
174 | =item B<-no_resumption_on_reneg> |
175 | ||
176 | set SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION flag. Only used by servers. | |
177 | ||
13cfb043 DSH |
178 | =item B<-legacyrenegotiation> |
179 | ||
180 | permits the use of unsafe legacy renegotiation. Equivalent to setting | |
181 | B<SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION>. | |
182 | ||
183 | =item B<-legacy_server_connect>, B<-no_legacy_server_connect> | |
184 | ||
185 | permits or prohibits the use of unsafe legacy renegotiation for OpenSSL | |
186 | clients only. Equivalent to setting or clearing B<SSL_OP_LEGACY_SERVER_CONNECT>. | |
187 | Set by default. | |
188 | ||
4e2bd9cb MC |
189 | =item B<-allow_no_dhe_kex> |
190 | ||
191 | In TLSv1.3 allow a non-(ec)dhe based key exchange mode on resumption. This means | |
192 | that there will be no forward secrecy for the resumed session. | |
193 | ||
13cfb043 DSH |
194 | =item B<-strict> |
195 | ||
196 | enables strict mode protocol handling. Equivalent to setting | |
197 | B<SSL_CERT_FLAG_TLS_STRICT>. | |
198 | ||
13cfb043 | 199 | =back |
3db935a9 DSH |
200 | |
201 | =head1 SUPPORTED CONFIGURATION FILE COMMANDS | |
202 | ||
203 | Currently supported B<cmd> names for configuration files (i.e. when the | |
204 | flag B<SSL_CONF_FLAG_FILE> is set) are listed below. All configuration file | |
854dfcd8 | 205 | B<cmd> names are case insensitive so B<signaturealgorithms> is recognised |
c7b7984a | 206 | as well as B<SignatureAlgorithms>. Unless otherwise stated the B<value> names |
3db935a9 DSH |
207 | are also case insensitive. |
208 | ||
209 | Note: the command prefix (if set) alters the recognised B<cmd> values. | |
210 | ||
211 | =over 4 | |
212 | ||
65f2a565 | 213 | =item B<CipherString> |
3db935a9 DSH |
214 | |
215 | Sets the cipher suite list to B<value>. Note: syntax checking of B<value> is | |
7946ab33 | 216 | currently not performed unless an B<SSL> or B<SSL_CTX> structure is |
3db935a9 DSH |
217 | associated with B<cctx>. |
218 | ||
ec2f7e56 DSH |
219 | =item B<Certificate> |
220 | ||
221 | Attempts to use the file B<value> as the certificate for the appropriate | |
fc1d88f0 RS |
222 | context. It currently uses SSL_CTX_use_certificate_chain_file() if an B<SSL_CTX> |
223 | structure is set or SSL_use_certificate_file() with filetype PEM if an B<SSL> | |
ec2f7e56 DSH |
224 | structure is set. This option is only supported if certificate operations |
225 | are permitted. | |
226 | ||
227 | =item B<PrivateKey> | |
228 | ||
229 | Attempts to use the file B<value> as the private key for the appropriate | |
230 | context. This option is only supported if certificate operations | |
2011b169 DSH |
231 | are permitted. Note: if no B<PrivateKey> option is set then a private key is |
232 | not loaded unless the B<SSL_CONF_FLAG_REQUIRE_PRIVATE> is set. | |
ec2f7e56 | 233 | |
429261d0 DSH |
234 | =item B<ChainCAFile>, B<ChainCAPath>, B<VerifyCAFile>, B<VerifyCAPath> |
235 | ||
236 | These options indicate a file or directory used for building certificate | |
237 | chains or verifying certificate chains. These options are only supported | |
238 | if certificate operations are permitted. | |
239 | ||
5a185729 DSH |
240 | =item B<RequestCAFile> |
241 | ||
242 | This option indicates a file containing a set of certificates in PEM form. | |
243 | The subject names of the certificates are sent to the peer in the | |
244 | B<certificate_authorities> extension for TLS 1.3 (in ClientHello or | |
245 | CertificateRequest) or in a certificate request for previous versions or | |
246 | TLS. | |
247 | ||
5b7f36e8 DSH |
248 | =item B<ServerInfoFile> |
249 | ||
250 | Attempts to use the file B<value> in the "serverinfo" extension using the | |
251 | function SSL_CTX_use_serverinfo_file. | |
252 | ||
c557f921 DSH |
253 | =item B<DHParameters> |
254 | ||
255 | Attempts to use the file B<value> as the set of temporary DH parameters for | |
256 | the appropriate context. This option is only supported if certificate | |
257 | operations are permitted. | |
258 | ||
c649d10d TS |
259 | =item B<RecordPadding> |
260 | ||
261 | Attempts to pad TLS 1.3 records so that they are a multiple of B<value> in | |
262 | length on send. A B<value> of 0 or 1 turns off padding. Otherwise, the | |
263 | B<value> must be >1 or <=16384. | |
264 | ||
db0f35dd TS |
265 | =item B<NoRenegotiation> |
266 | ||
267 | Disables all attempts at renegotiation in TLSv1.2 and earlier, same as setting | |
268 | B<SSL_OP_NO_RENEGOTIATION>. | |
269 | ||
3db935a9 DSH |
270 | =item B<SignatureAlgorithms> |
271 | ||
272 | This sets the supported signature algorithms for TLS v1.2. For clients this | |
273 | value is used directly for the supported signature algorithms extension. For | |
274 | servers it is used to determine which signature algorithms to support. | |
275 | ||
276 | The B<value> argument should be a colon separated list of signature algorithms | |
277 | in order of decreasing preference of the form B<algorithm+hash>. B<algorithm> | |
278 | is one of B<RSA>, B<DSA> or B<ECDSA> and B<hash> is a supported algorithm | |
279 | OID short name such as B<SHA1>, B<SHA224>, B<SHA256>, B<SHA384> of B<SHA512>. | |
280 | Note: algorithm and hash names are case sensitive. | |
281 | ||
282 | If this option is not set then all signature algorithms supported by the | |
283 | OpenSSL library are permissible. | |
284 | ||
285 | =item B<ClientSignatureAlgorithms> | |
286 | ||
287 | This sets the supported signature algorithms associated with client | |
288 | authentication for TLS v1.2. For servers the value is used in the supported | |
289 | signature algorithms field of a certificate request. For clients it is | |
c7b7984a | 290 | used to determine which signature algorithm to with the client certificate. |
3db935a9 DSH |
291 | |
292 | The syntax of B<value> is identical to B<SignatureAlgorithms>. If not set then | |
293 | the value set for B<SignatureAlgorithms> will be used instead. | |
294 | ||
47f7cf05 | 295 | =item B<Groups> |
3db935a9 | 296 | |
47f7cf05 MC |
297 | This sets the supported groups. For clients, the groups are |
298 | sent using the supported groups extension. For servers, it is used | |
299 | to determine which group to use. This setting affects groups used for both | |
300 | signatures and key exchange, if applicable. It also affects the preferred | |
301 | key_share sent by a client in a TLSv1.3 compatible connection. | |
3db935a9 | 302 | |
47f7cf05 MC |
303 | The B<value> argument is a colon separated list of groups. The group can be |
304 | either the B<NIST> name (e.g. B<P-256>), some other commonly used name where | |
305 | applicable (e.g. B<X25519>) or an OpenSSL OID name (e.g B<prime256v1>). Group | |
306 | names are case sensitive. The list should be in order of preference with the | |
307 | most preferred group first. The first listed group will be the one used for a | |
308 | key_share by a TLSv1.3 client. | |
309 | ||
310 | =item B<Curves> | |
311 | ||
312 | This is a synonym for the "Groups" command. | |
3db935a9 | 313 | |
7946ab33 KR |
314 | =item B<MinProtocol> |
315 | ||
316 | This sets the minimum supported SSL, TLS or DTLS version. | |
317 | ||
57ce7b61 VD |
318 | Currently supported protocol values are B<SSLv3>, B<TLSv1>, B<TLSv1.1>, |
319 | B<TLSv1.2>, B<DTLSv1> and B<DTLSv1.2>. | |
869e978c | 320 | The value B<None> will disable the limit. |
7946ab33 KR |
321 | |
322 | =item B<MaxProtocol> | |
323 | ||
324 | This sets the maximum supported SSL, TLS or DTLS version. | |
325 | ||
57ce7b61 VD |
326 | Currently supported protocol values are B<SSLv3>, B<TLSv1>, B<TLSv1.1>, |
327 | B<TLSv1.2>, B<DTLSv1> and B<DTLSv1.2>. | |
869e978c | 328 | The value B<None> will disable the limit. |
7946ab33 | 329 | |
3db935a9 DSH |
330 | =item B<Protocol> |
331 | ||
57ce7b61 VD |
332 | This can be used to enable or disable certain versions of the SSL, |
333 | TLS or DTLS protocol. | |
7946ab33 | 334 | |
57ce7b61 VD |
335 | The B<value> argument is a comma separated list of supported protocols |
336 | to enable or disable. | |
7946ab33 KR |
337 | If a protocol is preceded by B<-> that version is disabled. |
338 | ||
339 | All protocol versions are enabled by default. | |
57ce7b61 VD |
340 | You need to disable at least one protocol version for this setting have any |
341 | effect. | |
342 | Only enabling some protocol versions does not disable the other protocol | |
343 | versions. | |
7946ab33 | 344 | |
57ce7b61 VD |
345 | Currently supported protocol values are B<SSLv3>, B<TLSv1>, B<TLSv1.1>, |
346 | B<TLSv1.2>, B<DTLSv1> and B<DTLSv1.2>. | |
7946ab33 | 347 | The special value B<ALL> refers to all supported versions. |
3db935a9 | 348 | |
57ce7b61 VD |
349 | This can't enable protocols that are disabled using B<MinProtocol> |
350 | or B<MaxProtocol>, but can disable protocols that are still allowed | |
351 | by them. | |
7946ab33 KR |
352 | |
353 | The B<Protocol> command is fragile and deprecated; do not use it. | |
354 | Use B<MinProtocol> and B<MaxProtocol> instead. | |
57ce7b61 VD |
355 | If you do use B<Protocol>, make sure that the resulting range of enabled |
356 | protocols has no "holes", e.g. if TLS 1.0 and TLS 1.2 are both enabled, make | |
357 | sure to also leave TLS 1.1 enabled. | |
3db935a9 DSH |
358 | |
359 | =item B<Options> | |
360 | ||
361 | The B<value> argument is a comma separated list of various flags to set. | |
8106cb8b VD |
362 | If a flag string is preceded B<-> it is disabled. |
363 | See the L<SSL_CTX_set_options(3)> function for more details of | |
364 | individual options. | |
3db935a9 DSH |
365 | |
366 | Each option is listed below. Where an operation is enabled by default | |
367 | the B<-flag> syntax is needed to disable it. | |
368 | ||
369 | B<SessionTicket>: session ticket support, enabled by default. Inverse of | |
370 | B<SSL_OP_NO_TICKET>: that is B<-SessionTicket> is the same as setting | |
371 | B<SSL_OP_NO_TICKET>. | |
372 | ||
373 | B<Compression>: SSL/TLS compression support, enabled by default. Inverse | |
374 | of B<SSL_OP_NO_COMPRESSION>. | |
375 | ||
376 | B<EmptyFragments>: use empty fragments as a countermeasure against a | |
377 | SSL 3.0/TLS 1.0 protocol vulnerability affecting CBC ciphers. It | |
378 | is set by default. Inverse of B<SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS>. | |
379 | ||
c7b7984a | 380 | B<Bugs>: enable various bug workarounds. Same as B<SSL_OP_ALL>. |
3db935a9 | 381 | |
c7b7984a | 382 | B<DHSingle>: enable single use DH keys, set by default. Inverse of |
3db935a9 DSH |
383 | B<SSL_OP_DH_SINGLE>. Only used by servers. |
384 | ||
385 | B<ECDHSingle> enable single use ECDH keys, set by default. Inverse of | |
386 | B<SSL_OP_ECDH_SINGLE>. Only used by servers. | |
387 | ||
388 | B<ServerPreference> use server and not client preference order when | |
389 | determining which cipher suite, signature algorithm or elliptic curve | |
390 | to use for an incoming connection. Equivalent to | |
391 | B<SSL_OP_CIPHER_SERVER_PREFERENCE>. Only used by servers. | |
392 | ||
f0ef019d DSH |
393 | B<NoResumptionOnRenegotiation> set |
394 | B<SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION> flag. Only used by servers. | |
395 | ||
3db935a9 DSH |
396 | B<UnsafeLegacyRenegotiation> permits the use of unsafe legacy renegotiation. |
397 | Equivalent to B<SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION>. | |
398 | ||
399 | B<UnsafeLegacyServerConnect> permits the use of unsafe legacy renegotiation | |
400 | for OpenSSL clients only. Equivalent to B<SSL_OP_LEGACY_SERVER_CONNECT>. | |
401 | Set by default. | |
402 | ||
b3618f44 EK |
403 | B<EncryptThenMac>: use encrypt-then-mac extension, enabled by |
404 | default. Inverse of B<SSL_OP_NO_ENCRYPT_THEN_MAC>: that is, | |
405 | B<-EncryptThenMac> is the same as setting B<SSL_OP_NO_ENCRYPT_THEN_MAC>. | |
4e2bd9cb MC |
406 | |
407 | B<AllowNoDHEKEX>: In TLSv1.3 allow a non-(ec)dhe based key exchange mode on | |
408 | resumption. This means that there will be no forward secrecy for the resumed | |
409 | session. Equivalent to B<SSL_OP_ALLOW_NO_DHE_KEX>. | |
b3618f44 | 410 | |
429261d0 DSH |
411 | =item B<VerifyMode> |
412 | ||
413 | The B<value> argument is a comma separated list of flags to set. | |
414 | ||
415 | B<Peer> enables peer verification: for clients only. | |
416 | ||
417 | B<Request> requests but does not require a certificate from the client. | |
418 | Servers only. | |
419 | ||
420 | B<Require> requests and requires a certificate from the client: an error | |
421 | occurs if the client does not present a certificate. Servers only. | |
422 | ||
423 | B<Once> requests a certificate from a client only on the initial connection: | |
424 | not when renegotiating. Servers only. | |
425 | ||
426 | =item B<ClientCAFile>, B<ClientCAPath> | |
427 | ||
428 | A file or directory of certificates in PEM format whose names are used as the | |
429 | set of acceptable names for client CAs. Servers only. This option is only | |
430 | supported if certificate operations are permitted. | |
431 | ||
3db935a9 DSH |
432 | =back |
433 | ||
ec2f7e56 DSH |
434 | =head1 SUPPORTED COMMAND TYPES |
435 | ||
436 | The function SSL_CONF_cmd_value_type() currently returns one of the following | |
437 | types: | |
438 | ||
439 | =over 4 | |
440 | ||
441 | =item B<SSL_CONF_TYPE_UNKNOWN> | |
442 | ||
443 | The B<cmd> string is unrecognised, this return value can be use to flag | |
444 | syntax errors. | |
445 | ||
446 | =item B<SSL_CONF_TYPE_STRING> | |
447 | ||
448 | The value is a string without any specific structure. | |
449 | ||
450 | =item B<SSL_CONF_TYPE_FILE> | |
451 | ||
452 | The value is a file name. | |
453 | ||
454 | =item B<SSL_CONF_TYPE_DIR> | |
455 | ||
456 | The value is a directory name. | |
457 | ||
656b2605 DSH |
458 | =item B<SSL_CONF_TYPE_NONE> |
459 | ||
460 | The value string is not used e.g. a command line option which doesn't take an | |
461 | argument. | |
462 | ||
fa9d77dc CR |
463 | =back |
464 | ||
3db935a9 DSH |
465 | =head1 NOTES |
466 | ||
467 | The order of operations is significant. This can be used to set either defaults | |
468 | or values which cannot be overridden. For example if an application calls: | |
469 | ||
87d9cafa | 470 | SSL_CONF_cmd(ctx, "Protocol", "-SSLv3"); |
3db935a9 DSH |
471 | SSL_CONF_cmd(ctx, userparam, uservalue); |
472 | ||
87d9cafa | 473 | it will disable SSLv3 support by default but the user can override it. If |
3db935a9 DSH |
474 | however the call sequence is: |
475 | ||
476 | SSL_CONF_cmd(ctx, userparam, uservalue); | |
87d9cafa | 477 | SSL_CONF_cmd(ctx, "Protocol", "-SSLv3"); |
3db935a9 | 478 | |
87d9cafa | 479 | SSLv3 is B<always> disabled and attempt to override this by the user are |
3db935a9 DSH |
480 | ignored. |
481 | ||
f5f85f75 | 482 | By checking the return code of SSL_CONF_cmd() it is possible to query if a |
44e69951 | 483 | given B<cmd> is recognised, this is useful if SSL_CONF_cmd() values are |
3db935a9 DSH |
484 | mixed with additional application specific operations. |
485 | ||
f5f85f75 | 486 | For example an application might call SSL_CONF_cmd() and if it returns |
3db935a9 DSH |
487 | -2 (unrecognised command) continue with processing of application specific |
488 | commands. | |
489 | ||
f5f85f75 JS |
490 | Applications can also use SSL_CONF_cmd() to process command lines though the |
491 | utility function SSL_CONF_cmd_argv() is normally used instead. One way | |
821244cf DSH |
492 | to do this is to set the prefix to an appropriate value using |
493 | SSL_CONF_CTX_set1_prefix(), pass the current argument to B<cmd> and the | |
494 | following argument to B<value> (which may be NULL). | |
3db935a9 DSH |
495 | |
496 | In this case if the return value is positive then it is used to skip that | |
f5f85f75 | 497 | number of arguments as they have been processed by SSL_CONF_cmd(). If -2 is |
3db935a9 DSH |
498 | returned then B<cmd> is not recognised and application specific arguments |
499 | can be checked instead. If -3 is returned a required argument is missing | |
500 | and an error is indicated. If 0 is returned some other error occurred and | |
501 | this can be reported back to the user. | |
502 | ||
7946ab33 | 503 | The function SSL_CONF_cmd_value_type() can be used by applications to |
ec2f7e56 DSH |
504 | check for the existence of a command or to perform additional syntax |
505 | checking or translation of the command value. For example if the return | |
506 | value is B<SSL_CONF_TYPE_FILE> an application could translate a relative | |
507 | pathname to an absolute pathname. | |
508 | ||
3db935a9 DSH |
509 | =head1 EXAMPLES |
510 | ||
511 | Set supported signature algorithms: | |
512 | ||
513 | SSL_CONF_cmd(ctx, "SignatureAlgorithms", "ECDSA+SHA256:RSA+SHA256:DSA+SHA256"); | |
514 | ||
24c2cd39 | 515 | There are various ways to select the supported protocols. |
7946ab33 KR |
516 | |
517 | This set the minimum protocol version to TLSv1, and so disables SSLv3. | |
518 | This is the recommended way to disable protocols. | |
519 | ||
520 | SSL_CONF_cmd(ctx, "MinProtocol", "TLSv1"); | |
521 | ||
522 | The following also disables SSLv3: | |
523 | ||
524 | SSL_CONF_cmd(ctx, "Protocol", "-SSLv3"); | |
525 | ||
57ce7b61 VD |
526 | The following will first enable all protocols, and then disable |
527 | SSLv3. | |
528 | If no protocol versions were disabled before this has the same effect as | |
529 | "-SSLv3", but if some versions were disables this will re-enable them before | |
530 | disabling SSLv3. | |
3db935a9 | 531 | |
87d9cafa | 532 | SSL_CONF_cmd(ctx, "Protocol", "ALL,-SSLv3"); |
3db935a9 DSH |
533 | |
534 | Only enable TLSv1.2: | |
535 | ||
7946ab33 KR |
536 | SSL_CONF_cmd(ctx, "MinProtocol", "TLSv1.2"); |
537 | SSL_CONF_cmd(ctx, "MaxProtocol", "TLSv1.2"); | |
538 | ||
539 | This also only enables TLSv1.2: | |
540 | ||
3db935a9 DSH |
541 | SSL_CONF_cmd(ctx, "Protocol", "-ALL,TLSv1.2"); |
542 | ||
543 | Disable TLS session tickets: | |
544 | ||
545 | SSL_CONF_cmd(ctx, "Options", "-SessionTicket"); | |
546 | ||
dc5744cb EK |
547 | Enable compression: |
548 | ||
549 | SSL_CONF_cmd(ctx, "Options", "Compression"); | |
550 | ||
3db935a9 DSH |
551 | Set supported curves to P-256, P-384: |
552 | ||
553 | SSL_CONF_cmd(ctx, "Curves", "P-256:P-384"); | |
554 | ||
555 | Set automatic support for any elliptic curve for key exchange: | |
556 | ||
557 | SSL_CONF_cmd(ctx, "ECDHParameters", "Automatic"); | |
558 | ||
559 | =head1 RETURN VALUES | |
560 | ||
4365e4aa | 561 | SSL_CONF_cmd() returns 1 if the value of B<cmd> is recognised and B<value> is |
3db935a9 DSH |
562 | B<NOT> used and 2 if both B<cmd> and B<value> are used. In other words it |
563 | returns the number of arguments processed. This is useful when processing | |
564 | command lines. | |
565 | ||
566 | A return value of -2 means B<cmd> is not recognised. | |
567 | ||
568 | A return value of -3 means B<cmd> is recognised and the command requires a | |
569 | value but B<value> is NULL. | |
570 | ||
571 | A return code of 0 indicates that both B<cmd> and B<value> are valid but an | |
572 | error occurred attempting to perform the operation: for example due to an | |
573 | error in the syntax of B<value> in this case the error queue may provide | |
574 | additional information. | |
575 | ||
576 | =head1 SEE ALSO | |
577 | ||
9b86974e RS |
578 | L<SSL_CONF_CTX_new(3)>, |
579 | L<SSL_CONF_CTX_set_flags(3)>, | |
580 | L<SSL_CONF_CTX_set1_prefix(3)>, | |
581 | L<SSL_CONF_CTX_set_ssl_ctx(3)>, | |
8106cb8b VD |
582 | L<SSL_CONF_cmd_argv(3)>, |
583 | L<SSL_CTX_set_options(3)> | |
3db935a9 DSH |
584 | |
585 | =head1 HISTORY | |
586 | ||
4365e4aa | 587 | SSL_CONF_cmd() was first added to OpenSSL 1.0.2 |
3db935a9 | 588 | |
57ce7b61 VD |
589 | B<SSL_OP_NO_SSL2> doesn't have effect since 1.1.0, but the macro is retained |
590 | for backwards compatibility. | |
45f55f6a | 591 | |
656b2605 DSH |
592 | B<SSL_CONF_TYPE_NONE> was first added to OpenSSL 1.1.0. In earlier versions of |
593 | OpenSSL passing a command which didn't take an argument would return | |
594 | B<SSL_CONF_TYPE_UNKNOWN>. | |
595 | ||
7946ab33 KR |
596 | B<MinProtocol> and B<MaxProtocol> where added in OpenSSL 1.1.0. |
597 | ||
e2f92610 RS |
598 | =head1 COPYRIGHT |
599 | ||
600 | Copyright 2012-2016 The OpenSSL Project Authors. All Rights Reserved. | |
601 | ||
602 | Licensed under the OpenSSL license (the "License"). You may not use | |
603 | this file except in compliance with the License. You can obtain a copy | |
604 | in the file LICENSE in the source distribution or at | |
605 | L<https://www.openssl.org/source/license.html>. | |
606 | ||
607 | =cut |