xref: /openssl/doc/man3/OSSL_CMP_CTX_new.pod (revision ac91bd88) 
1=pod
2
3=head1 NAME
4
5OSSL_CMP_CTX_new,
6OSSL_CMP_CTX_free,
7OSSL_CMP_CTX_reinit,
8OSSL_CMP_CTX_get0_libctx, OSSL_CMP_CTX_get0_propq,
9OSSL_CMP_CTX_set_option,
10OSSL_CMP_CTX_get_option,
11OSSL_CMP_CTX_set_log_cb,
12OSSL_CMP_CTX_set_log_verbosity,
13OSSL_CMP_CTX_print_errors,
14OSSL_CMP_CTX_set1_serverPath,
15OSSL_CMP_CTX_set1_server,
16OSSL_CMP_CTX_set_serverPort,
17OSSL_CMP_CTX_set1_proxy,
18OSSL_CMP_CTX_set1_no_proxy,
19OSSL_CMP_CTX_set_http_cb,
20OSSL_CMP_CTX_set_http_cb_arg,
21OSSL_CMP_CTX_get_http_cb_arg,
22OSSL_CMP_transfer_cb_t,
23OSSL_CMP_CTX_set_transfer_cb,
24OSSL_CMP_CTX_set_transfer_cb_arg,
25OSSL_CMP_CTX_get_transfer_cb_arg,
26OSSL_CMP_CTX_set1_srvCert,
27OSSL_CMP_CTX_set1_expected_sender,
28OSSL_CMP_CTX_set0_trusted,
29OSSL_CMP_CTX_set0_trustedStore,
30OSSL_CMP_CTX_get0_trusted,
31OSSL_CMP_CTX_get0_trustedStore,
32OSSL_CMP_CTX_set1_untrusted,
33OSSL_CMP_CTX_get0_untrusted,
34OSSL_CMP_CTX_set1_cert,
35OSSL_CMP_CTX_build_cert_chain,
36OSSL_CMP_CTX_set1_pkey,
37OSSL_CMP_CTX_set1_referenceValue,
38OSSL_CMP_CTX_set1_secretValue,
39OSSL_CMP_CTX_set1_recipient,
40OSSL_CMP_CTX_push0_geninfo_ITAV,
41OSSL_CMP_CTX_reset_geninfo_ITAVs,
42OSSL_CMP_CTX_get0_geninfo_ITAVs,
43OSSL_CMP_CTX_set1_extraCertsOut,
44OSSL_CMP_CTX_set0_newPkey,
45OSSL_CMP_CTX_get0_newPkey,
46OSSL_CMP_CTX_set1_issuer,
47OSSL_CMP_CTX_set1_serialNumber,
48OSSL_CMP_CTX_set1_subjectName,
49OSSL_CMP_CTX_push1_subjectAltName,
50OSSL_CMP_CTX_set0_reqExtensions,
51OSSL_CMP_CTX_reqExtensions_have_SAN,
52OSSL_CMP_CTX_push0_policy,
53OSSL_CMP_CTX_set1_oldCert,
54OSSL_CMP_CTX_set1_p10CSR,
55OSSL_CMP_CTX_push0_genm_ITAV,
56OSSL_CMP_certConf_cb_t,
57OSSL_CMP_certConf_cb,
58OSSL_CMP_CTX_set_certConf_cb,
59OSSL_CMP_CTX_set_certConf_cb_arg,
60OSSL_CMP_CTX_get_certConf_cb_arg,
61OSSL_CMP_CTX_get_status,
62OSSL_CMP_CTX_get0_statusString,
63OSSL_CMP_CTX_get_failInfoCode,
64OSSL_CMP_CTX_get0_validatedSrvCert,
65OSSL_CMP_CTX_get0_newCert,
66OSSL_CMP_CTX_get1_newChain,
67OSSL_CMP_CTX_get1_caPubs,
68OSSL_CMP_CTX_get1_extraCertsIn,
69OSSL_CMP_CTX_set1_transactionID,
70OSSL_CMP_CTX_set1_senderNonce
71- functions for managing the CMP client context data structure
72
73=head1 SYNOPSIS
74
75 #include <openssl/cmp.h>
76
77 OSSL_CMP_CTX *OSSL_CMP_CTX_new(OSSL_LIB_CTX *libctx, const char *propq);
78 void OSSL_CMP_CTX_free(OSSL_CMP_CTX *ctx);
79 int OSSL_CMP_CTX_reinit(OSSL_CMP_CTX *ctx);
80 OSSL_LIB_CTX *OSSL_CMP_CTX_get0_libctx(const OSSL_CMP_CTX *ctx);
81 const char *OSSL_CMP_CTX_get0_propq(const OSSL_CMP_CTX *ctx);
82 int OSSL_CMP_CTX_set_option(OSSL_CMP_CTX *ctx, int opt, int val);
83 int OSSL_CMP_CTX_get_option(const OSSL_CMP_CTX *ctx, int opt);
84
85 /* logging and error reporting: */
86 int OSSL_CMP_CTX_set_log_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_log_cb_t cb);
87 #define OSSL_CMP_CTX_set_log_verbosity(ctx, level)
88 void OSSL_CMP_CTX_print_errors(const OSSL_CMP_CTX *ctx);
89
90 /* message transfer: */
91 int OSSL_CMP_CTX_set1_serverPath(OSSL_CMP_CTX *ctx, const char *path);
92 int OSSL_CMP_CTX_set1_server(OSSL_CMP_CTX *ctx, const char *address);
93 int OSSL_CMP_CTX_set_serverPort(OSSL_CMP_CTX *ctx, int port);
94 int OSSL_CMP_CTX_set1_proxy(OSSL_CMP_CTX *ctx, const char *name);
95 int OSSL_CMP_CTX_set1_no_proxy(OSSL_CMP_CTX *ctx, const char *names);
96 int OSSL_CMP_CTX_set_http_cb(OSSL_CMP_CTX *ctx, HTTP_bio_cb_t cb);
97 int OSSL_CMP_CTX_set_http_cb_arg(OSSL_CMP_CTX *ctx, void *arg);
98 void *OSSL_CMP_CTX_get_http_cb_arg(const OSSL_CMP_CTX *ctx);
99 typedef OSSL_CMP_MSG *(*OSSL_CMP_transfer_cb_t)(OSSL_CMP_CTX *ctx,
100                                                 const OSSL_CMP_MSG *req);
101 int OSSL_CMP_CTX_set_transfer_cb(OSSL_CMP_CTX *ctx,
102                                  OSSL_CMP_transfer_cb_t cb);
103 int OSSL_CMP_CTX_set_transfer_cb_arg(OSSL_CMP_CTX *ctx, void *arg);
104 void *OSSL_CMP_CTX_get_transfer_cb_arg(const OSSL_CMP_CTX *ctx);
105
106 /* server authentication: */
107 int OSSL_CMP_CTX_set1_srvCert(OSSL_CMP_CTX *ctx, X509 *cert);
108 int OSSL_CMP_CTX_set1_expected_sender(OSSL_CMP_CTX *ctx,
109                                      const X509_NAME *name);
110 #define OSSL_CMP_CTX_set0_trusted OSSL_CMP_CTX_set0_trustedStore
111 int OSSL_CMP_CTX_set0_trustedStore(OSSL_CMP_CTX *ctx, X509_STORE *store);
112 #define OSSL_CMP_CTX_get0_trusted OSSL_CMP_CTX_get0_trustedStore
113 X509_STORE *OSSL_CMP_CTX_get0_trustedStore(const OSSL_CMP_CTX *ctx);
114 int OSSL_CMP_CTX_set1_untrusted(OSSL_CMP_CTX *ctx, STACK_OF(X509) *certs);
115 STACK_OF(X509) *OSSL_CMP_CTX_get0_untrusted(const OSSL_CMP_CTX *ctx);
116
117 /* client authentication: */
118 int OSSL_CMP_CTX_set1_cert(OSSL_CMP_CTX *ctx, X509 *cert);
119 int OSSL_CMP_CTX_build_cert_chain(OSSL_CMP_CTX *ctx, X509_STORE *own_trusted,
120                                   STACK_OF(X509) *candidates);
121 int OSSL_CMP_CTX_set1_pkey(OSSL_CMP_CTX *ctx, EVP_PKEY *pkey);
122 int OSSL_CMP_CTX_set1_referenceValue(OSSL_CMP_CTX *ctx,
123                                      const unsigned char *ref, int len);
124 int OSSL_CMP_CTX_set1_secretValue(OSSL_CMP_CTX *ctx,
125                                   const unsigned char *sec, int len);
126
127 /* CMP message header and extra certificates: */
128 int OSSL_CMP_CTX_set1_recipient(OSSL_CMP_CTX *ctx, const X509_NAME *name);
129 int OSSL_CMP_CTX_push0_geninfo_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav);
130 int OSSL_CMP_CTX_reset_geninfo_ITAVs(OSSL_CMP_CTX *ctx);
131 STACK_OF(OSSL_CMP_ITAV)
132     *OSSL_CMP_CTX_get0_geninfo_ITAVs(const OSSL_CMP_CTX *ctx);
133 int OSSL_CMP_CTX_set1_extraCertsOut(OSSL_CMP_CTX *ctx,
134                                     STACK_OF(X509) *extraCertsOut);
135
136 /* certificate template: */
137 int OSSL_CMP_CTX_set0_newPkey(OSSL_CMP_CTX *ctx, int priv, EVP_PKEY *pkey);
138 EVP_PKEY *OSSL_CMP_CTX_get0_newPkey(const OSSL_CMP_CTX *ctx, int priv);
139 int OSSL_CMP_CTX_set1_issuer(OSSL_CMP_CTX *ctx, const X509_NAME *name);
140 int OSSL_CMP_CTX_set1_serialNumber(OSSL_CMP_CTX *ctx, const ASN1_INTEGER *sn);
141 int OSSL_CMP_CTX_set1_subjectName(OSSL_CMP_CTX *ctx, const X509_NAME *name);
142 int OSSL_CMP_CTX_push1_subjectAltName(OSSL_CMP_CTX *ctx,
143                                       const GENERAL_NAME *name);
144 int OSSL_CMP_CTX_set0_reqExtensions(OSSL_CMP_CTX *ctx, X509_EXTENSIONS *exts);
145 int OSSL_CMP_CTX_reqExtensions_have_SAN(OSSL_CMP_CTX *ctx);
146 int OSSL_CMP_CTX_push0_policy(OSSL_CMP_CTX *ctx, POLICYINFO *pinfo);
147 int OSSL_CMP_CTX_set1_oldCert(OSSL_CMP_CTX *ctx, X509 *cert);
148 int OSSL_CMP_CTX_set1_p10CSR(OSSL_CMP_CTX *ctx, const X509_REQ *csr);
149
150 /* misc body contents: */
151 int OSSL_CMP_CTX_push0_genm_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav);
152
153 /* certificate confirmation: */
154 typedef int (*OSSL_CMP_certConf_cb_t)(OSSL_CMP_CTX *ctx, X509 *cert,
155                                       int fail_info, const char **txt);
156 int OSSL_CMP_certConf_cb(OSSL_CMP_CTX *ctx, X509 *cert, int fail_info,
157                          const char **text);
158 int OSSL_CMP_CTX_set_certConf_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_certConf_cb_t cb);
159 int OSSL_CMP_CTX_set_certConf_cb_arg(OSSL_CMP_CTX *ctx, void *arg);
160 void *OSSL_CMP_CTX_get_certConf_cb_arg(const OSSL_CMP_CTX *ctx);
161
162 /* result fetching: */
163 int OSSL_CMP_CTX_get_status(const OSSL_CMP_CTX *ctx);
164 OSSL_CMP_PKIFREETEXT *OSSL_CMP_CTX_get0_statusString(const OSSL_CMP_CTX *ctx);
165 int OSSL_CMP_CTX_get_failInfoCode(const OSSL_CMP_CTX *ctx);
166
167 X509 *OSSL_CMP_CTX_get0_validatedSrvCert(const OSSL_CMP_CTX *ctx);
168 X509 *OSSL_CMP_CTX_get0_newCert(const OSSL_CMP_CTX *ctx);
169 STACK_OF(X509) *OSSL_CMP_CTX_get1_newChain(const OSSL_CMP_CTX *ctx);
170 STACK_OF(X509) *OSSL_CMP_CTX_get1_caPubs(const OSSL_CMP_CTX *ctx);
171 STACK_OF(X509) *OSSL_CMP_CTX_get1_extraCertsIn(const OSSL_CMP_CTX *ctx);
172
173 /* for testing and debugging purposes: */
174 int OSSL_CMP_CTX_set1_transactionID(OSSL_CMP_CTX *ctx,
175                                     const ASN1_OCTET_STRING *id);
176 int OSSL_CMP_CTX_set1_senderNonce(OSSL_CMP_CTX *ctx,
177                                   const ASN1_OCTET_STRING *nonce);
178
179=head1 DESCRIPTION
180
181This is the context API for using CMP (Certificate Management Protocol) with
182OpenSSL.
183
184OSSL_CMP_CTX_new() allocates an B<OSSL_CMP_CTX> structure associated with
185the library context I<libctx> and property query string I<propq>,
186both of which may be NULL to select the defaults.
187It initializes the remaining fields to their default values - for instance,
188the logging verbosity is set to OSSL_CMP_LOG_INFO,
189the message timeout is set to 120 seconds,
190and the proof-of-possession method is set to OSSL_CRMF_POPO_SIGNATURE.
191
192OSSL_CMP_CTX_free() deallocates an OSSL_CMP_CTX structure.
193If the argument is NULL, nothing is done.
194
195OSSL_CMP_CTX_reinit() prepares the given I<ctx> for a further transaction by
196clearing the internal CMP transaction (aka session) status, PKIStatusInfo,
197and any previous results (newCert, newChain, caPubs, and extraCertsIn)
198from the last executed transaction.
199It also clears any ITAVs that were added by OSSL_CMP_CTX_push0_genm_ITAV().
200All other field values (i.e., CMP options) are retained for potential reuse.
201
202OSSL_CMP_CTX_get0_libctx() returns the I<libctx> argument that was used
203when constructing I<ctx> with OSSL_CMP_CTX_new(), which may be NULL.
204
205OSSL_CMP_CTX_get0_propq() returns the I<propq> argument that was used
206when constructing I<ctx> with OSSL_CMP_CTX_new(), which may be NULL.
207
208OSSL_CMP_CTX_set_option() sets the given value for the given option
209(e.g., OSSL_CMP_OPT_IMPLICIT_CONFIRM) in the given OSSL_CMP_CTX structure.
210
211The following options can be set:
212
213=over 4
214
215=item B<OSSL_CMP_OPT_LOG_VERBOSITY>
216
217        The level of severity needed for actually outputting log messages
218        due to errors, warnings, general info, debugging, etc.
219        Default is OSSL_CMP_LOG_INFO. See also L<OSSL_CMP_log_open(3)>.
220
221=item B<OSSL_CMP_OPT_KEEP_ALIVE>
222
223        If the given value is 0 then HTTP connections are not kept open
224        after receiving a response, which is the default behavior for HTTP 1.0.
225        If the value is 1 or 2 then persistent connections are requested.
226        If the value is 2 then persistent connections are required,
227        i.e., in case the server does not grant them an error occurs.
228        The default value is 1: prefer to keep the connection open.
229
230=item B<OSSL_CMP_OPT_MSG_TIMEOUT>
231
232        Number of seconds a CMP request-response message round trip
233        is allowed to take before a timeout error is returned.
234        A value <= 0 means no limitation (waiting indefinitely).
235        Default is to use the B<OSSL_CMP_OPT_TOTAL_TIMEOUT> setting.
236
237=item B<OSSL_CMP_OPT_TOTAL_TIMEOUT>
238
239        Maximum total number of seconds a transaction may take,
240        including polling etc.
241        A value <= 0 means no limitation (waiting indefinitely).
242        Default is 0.
243
244=item B<OSSL_CMP_OPT_USE_TLS>
245
246        Use this option to indicate to the HTTP implementation
247        whether TLS is going to be used for the connection (resulting in HTTPS).
248        The value 1 indicates that TLS is used for client-side HTTP connections,
249        which needs to be implemented via a callback function set by
250        OSSL_CMP_CTX_set_http_cb().
251        The value 0 indicates that TLS is not used.
252        Default is -1 for backward compatibility: TLS is used by the client side
253        if and only if OSSL_CMP_CTX_set_http_cb_arg() sets a non-NULL I<arg>.
254
255=item B<OSSL_CMP_OPT_VALIDITY_DAYS>
256
257        Number of days new certificates are asked to be valid for.
258
259=item B<OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT>
260
261        Do not take default Subject Alternative Names
262        from the reference certificate.
263
264=item B<OSSL_CMP_OPT_SUBJECTALTNAME_CRITICAL>
265
266        Demand that the given Subject Alternative Names are flagged as critical.
267
268=item B<OSSL_CMP_OPT_POLICIES_CRITICAL>
269
270        Demand that the given policies are flagged as critical.
271
272=item B<OSSL_CMP_OPT_POPO_METHOD>
273
274        Select the proof of possession method to use. Possible values are:
275
276            OSSL_CRMF_POPO_NONE       - ProofOfPossession field omitted
277            OSSL_CRMF_POPO_RAVERIFIED - assert that the RA has already
278                                        verified the PoPo
279            OSSL_CRMF_POPO_SIGNATURE  - sign a value with private key,
280                                        which is the default.
281            OSSL_CRMF_POPO_KEYENC     - decrypt the encrypted certificate
282                                        ("indirect method")
283
284        Note that a signature-based POPO can only be produced if a private key
285        is provided as the newPkey or client's pkey component of the CMP context.
286
287=item B<OSSL_CMP_OPT_DIGEST_ALGNID>
288
289        The NID of the digest algorithm to be used in RFC 4210's MSG_SIG_ALG
290        for signature-based message protection and Proof-of-Possession (POPO).
291        Default is SHA256.
292
293=item B<OSSL_CMP_OPT_OWF_ALGNID>
294        The NID of the digest algorithm to be used as one-way function (OWF)
295        for MAC-based message protection with password-based MAC (PBM).
296        See RFC 4210 section 5.1.3.1 for details.
297        Default is SHA256.
298
299=item B<OSSL_CMP_OPT_MAC_ALGNID>
300        The NID of the MAC algorithm to be used for message protection with PBM.
301        Default is HMAC-SHA1 as per RFC 4210.
302
303=item B<OSSL_CMP_OPT_REVOCATION_REASON>
304
305        The reason code to be included in a Revocation Request (RR);
306        values: 0..10 (RFC 5210, 5.3.1) or -1 for none, which is the default.
307
308=item B<OSSL_CMP_OPT_IMPLICIT_CONFIRM>
309
310        Request server to enable implicit confirm mode, where the client
311        does not need to send confirmation upon receiving the
312        certificate. If the server does not enable implicit confirmation
313        in the return message, then confirmation is sent anyway.
314
315=item B<OSSL_CMP_OPT_DISABLE_CONFIRM>
316
317        Do not confirm enrolled certificates, to cope with broken servers
318        not supporting implicit confirmation correctly.
319B<WARNING:> This setting leads to unspecified behavior and it is meant
320exclusively to allow interoperability with server implementations violating
321RFC 4210.
322
323=item B<OSSL_CMP_OPT_UNPROTECTED_SEND>
324
325        Send request or response messages without CMP-level protection.
326
327=item B<OSSL_CMP_OPT_UNPROTECTED_ERRORS>
328
329        Accept unprotected error responses which are either explicitly
330        unprotected or where protection verification failed. Applies to regular
331        error messages as well as certificate responses (IP/CP/KUP) and
332        revocation responses (RP) with rejection.
333B<WARNING:> This setting leads to unspecified behavior and it is meant
334exclusively to allow interoperability with server implementations violating
335RFC 4210.
336
337=item B<OSSL_CMP_OPT_IGNORE_KEYUSAGE>
338
339        Ignore key usage restrictions in the signer's certificate when
340        validating signature-based protection in received CMP messages.
341        Else, 'digitalSignature' must be allowed by CMP signer certificates.
342
343=item B<OSSL_CMP_OPT_PERMIT_TA_IN_EXTRACERTS_FOR_IR>
344
345        Allow retrieving a trust anchor from extraCerts and using that
346        to validate the certificate chain of an IP message.
347        This is a quirk option added to support 3GPP TS 33.310.
348
349        Note that using this option is dangerous as the certificate obtained
350        this way has not been authenticated (at least not at CMP level).
351        Taking it over as a trust anchor implements trust-on-first-use (TOFU).
352
353=item B<OSSL_CMP_OPT_NO_CACHE_EXTRACERTS>
354
355        Do not cache certificates received in the extraCerts CMP message field.
356        Otherwise they are stored to potentially help validate further messages.
357
358=back
359
360OSSL_CMP_CTX_get_option() reads the current value of the given option
361(e.g., OSSL_CMP_OPT_IMPLICIT_CONFIRM) from the given OSSL_CMP_CTX structure.
362
363OSSL_CMP_CTX_set_log_cb() sets in I<ctx> the callback function I<cb>
364for handling error queue entries and logging messages.
365When I<cb> is NULL errors are printed to STDERR (if available, else ignored)
366any log messages are ignored.
367Alternatively, L<OSSL_CMP_log_open(3)> may be used to direct logging to STDOUT.
368
369OSSL_CMP_CTX_set_log_verbosity() is a macro setting the
370OSSL_CMP_OPT_LOG_VERBOSITY context option to the given level.
371
372OSSL_CMP_CTX_print_errors() outputs any entries in the OpenSSL error queue. It
373is similar to L<ERR_print_errors_cb(3)> but uses the CMP log callback function
374if set in the I<ctx> for uniformity with CMP logging if given. Otherwise it uses
375L<ERR_print_errors(3)> to print to STDERR (unless OPENSSL_NO_STDIO is defined).
376
377OSSL_CMP_CTX_set1_serverPath() sets the HTTP path of the CMP server on the host,
378also known as "CMP alias".
379The default is C</>.
380
381OSSL_CMP_CTX_set1_server() sets the given server I<address>
382(which may be a hostname or IP address or NULL) in the given I<ctx>.
383
384OSSL_CMP_CTX_set_serverPort() sets the port of the CMP server to connect to.
385If not used or the I<port> argument is 0
386the default port applies, which is 80 for HTTP and 443 for HTTPS.
387
388OSSL_CMP_CTX_set1_proxy() sets the HTTP proxy to be used for connecting to
389the given CMP server unless overruled by any "no_proxy" settings (see below).
390If TLS is not used this defaults to the value of
391the environment variable C<http_proxy> if set, else C<HTTP_PROXY>.
392Otherwise defaults to the value of C<https_proxy> if set, else C<HTTPS_PROXY>.
393An empty proxy string specifies not to use a proxy.
394Otherwise the format is
395C<[http[s]://][userinfo@]host[:port][/path][?query][#fragment]>,
396where any given userinfo, path, query, and fragment is ignored.
397If the host string is an IPv6 address, it must be enclosed in C<[> and C<]>.
398The default port number is 80, or 443 in case C<https:> is given.
399
400OSSL_CMP_CTX_set1_no_proxy() sets the list of server hostnames not to use
401an HTTP proxy for. The names may be separated by commas and/or whitespace.
402Defaults to the environment variable C<no_proxy> if set, else C<NO_PROXY>.
403
404OSSL_CMP_CTX_set_http_cb() sets the optional BIO connect/disconnect callback
405function, which has the prototype
406
407 typedef BIO *(*HTTP_bio_cb_t) (BIO *bio, void *arg, int connect, int detail);
408
409The callback may modify the I<bio> provided by L<OSSL_CMP_MSG_http_perform(3)>
410as described for the I<bio_update_fn> parameter of L<OSSL_HTTP_open(3)>.
411The callback may make use of a custom defined argument I<arg>,
412as described for the I<arg> parameter of L<OSSL_HTTP_open(3)>.
413The argument is stored in the OSSL_CMP_CTX using OSSL_CMP_CTX_set_http_cb_arg().
414See also the B<OSSL_CMP_OPT_USE_TLS> option described above.
415
416OSSL_CMP_CTX_set_http_cb_arg() sets the argument, respectively a pointer to
417a structure containing arguments such as an B<SSL_CTX> structure,
418optionally to be used by the http connect/disconnect callback function.
419I<arg> is not consumed, and it must therefore explicitly be freed when not
420needed any more. I<arg> may be NULL to clear the entry.
421
422OSSL_CMP_CTX_get_http_cb_arg() gets the argument, respectively the pointer to a
423structure containing arguments, previously set by
424OSSL_CMP_CTX_set_http_cb_arg() or NULL if unset.
425
426OSSL_CMP_CTX_set_transfer_cb() sets the message transfer callback function,
427which has the type
428
429 typedef OSSL_CMP_MSG *(*OSSL_CMP_transfer_cb_t) (OSSL_CMP_CTX *ctx,
430                                                  const OSSL_CMP_MSG *req);
431
432Default is NULL, which implies the use of L<OSSL_CMP_MSG_http_perform(3)>.
433The callback should send the CMP request message it obtains via the I<req>
434parameter and on success return the response, else it must return NULL.
435The transfer callback may make use of a custom defined argument stored in
436the ctx by means of OSSL_CMP_CTX_set_transfer_cb_arg(), which may be retrieved
437again through OSSL_CMP_CTX_get_transfer_cb_arg().
438
439OSSL_CMP_CTX_set_transfer_cb_arg() sets an argument, respectively a pointer to a
440structure containing arguments, optionally to be used by the transfer callback.
441I<arg> is not consumed, and it must therefore explicitly be freed when not
442needed any more. I<arg> may be NULL to clear the entry.
443
444OSSL_CMP_CTX_get_transfer_cb_arg() gets the argument, respectively the pointer
445to a structure containing arguments, previously set by
446OSSL_CMP_CTX_set_transfer_cb_arg() or NULL if unset.
447
448OSSL_CMP_CTX_set1_srvCert() sets the expected server cert in I<ctx> and trusts
449it directly (even if it is expired) when verifying signed response messages.
450This pins the accepted CMP server
451and results in ignoring whatever may be set using OSSL_CMP_CTX_set0_trusted().
452Any previously set value is freed.
453The I<cert> argument may be NULL to clear the entry.
454If set, the subject of the certificate is also used
455as default value for the recipient of CMP requests
456and as default value for the expected sender of CMP responses.
457
458OSSL_CMP_CTX_set1_expected_sender() sets the Distinguished Name (DN)
459expected in the sender field of incoming CMP messages.
460Defaults to the subject of the pinned server certificate, if any.
461This can be used to make sure that only a particular entity is accepted as
462CMP message signer, and attackers are not able to use arbitrary certificates
463of a trusted PKI hierarchy to fraudulently pose as CMP server.
464Note that this gives slightly more freedom than OSSL_CMP_CTX_set1_srvCert(),
465which pins the server to the holder of a particular certificate, while the
466expected sender name will continue to match after updates of the server cert.
467
468OSSL_CMP_CTX_set0_trusted() is an alias of the original
469OSSL_CMP_CTX_set0_trustedStore().
470It sets in the CMP context I<ctx> the certificate store of type X509_STORE
471containing trusted certificates, typically of root CAs.
472This is ignored when a certificate is pinned using OSSL_CMP_CTX_set1_srvCert().
473The store may also hold CRLs and a certificate verification callback function
474used for signature-based peer authentication.
475Any store entry already set before is freed.
476When given a NULL parameter the entry is cleared.
477
478OSSL_CMP_CTX_get0_trusted() is an alias of the original
479OSSL_CMP_CTX_get0_trustedStore().
480It extracts from the CMP context I<ctx> the pointer to the currently set
481certificate store containing trust anchors etc., or an empty store if unset.
482
483OSSL_CMP_CTX_set1_untrusted() sets up a list of non-trusted certificates
484of intermediate CAs that may be useful for path construction for the own CMP
485signer certificate, for the own TLS certificate (if any), when verifying peer
486CMP protection certificates, and when verifying newly enrolled certificates.
487The reference counts of those certificates handled successfully are increased.
488This list of untrusted certificates in I<ctx> will get augmented by extraCerts
489in received CMP messages unless B<OSSL_CMP_OPT_NO_CACHE_EXTRACERTS> is set.
490
491OSSL_CMP_CTX_get0_untrusted() returns a pointer to the
492list of untrusted certs in I<ctx>, which may be empty if unset.
493
494OSSL_CMP_CTX_set1_cert() sets the CMP I<signer certificate>,
495also called I<protection certificate>,
496related to the private key used for signature-based CMP message protection.
497Therefore the public key of this I<cert> must correspond to
498the private key set before or thereafter via OSSL_CMP_CTX_set1_pkey().
499When using signature-based protection of CMP request messages
500this CMP signer certificate will be included first in the extraCerts field.
501It serves as fallback reference certificate, see OSSL_CMP_CTX_set1_oldCert().
502The subject of this I<cert> will be used as the sender field of outgoing
503messages, while the subject of any cert set via OSSL_CMP_CTX_set1_oldCert(),
504the subject of any PKCS#10 CSR set via OSSL_CMP_CTX_set1_p10CSR(),
505and any value set via OSSL_CMP_CTX_set1_subjectName() are used as fallback.
506
507The I<cert> argument may be NULL to clear the entry.
508
509OSSL_CMP_CTX_build_cert_chain() builds a certificate chain for the CMP signer
510certificate previously set in the I<ctx>. It adds the optional I<candidates>,
511a list of intermediate CA certs that may already constitute the targeted chain,
512to the untrusted certs that may already exist in the I<ctx>.
513Then the function uses this augmented set of certs for chain construction.
514If I<own_trusted> is NULL it builds the chain as far down as possible and
515ignores any verification errors. Else the CMP signer certificate must be
516verifiable where the chain reaches a trust anchor contained in I<own_trusted>.
517On success the function stores the resulting chain in I<ctx>
518for inclusion in the extraCerts field of signature-protected messages.
519Calling this function is optional; by default a chain construction
520is performed on demand that is equivalent to calling this function
521with the I<candidates> and I<own_trusted> arguments being NULL.
522
523OSSL_CMP_CTX_set1_pkey() sets the client's private key corresponding to the
524CMP signer certificate set via OSSL_CMP_CTX_set1_cert().
525This key is used create signature-based protection (protectionAlg = MSG_SIG_ALG)
526of outgoing messages
527unless a symmetric secret has been set via OSSL_CMP_CTX_set1_secretValue().
528The I<pkey> argument may be NULL to clear the entry.
529
530OSSL_CMP_CTX_set1_secretValue() sets in I<ctx> the byte string I<sec> of length
531I<len> to use as pre-shared secret, or clears it if the I<sec> argument is NULL.
532If present, this secret is used to create MAC-based authentication and integrity
533protection (rather than applying signature-based protection)
534of outgoing messages and to verify authenticity and integrity of incoming
535messages that have MAC-based protection (protectionAlg = C<MSG_MAC_ALG>).
536
537OSSL_CMP_CTX_set1_referenceValue() sets the given referenceValue I<ref> with
538length I<len> in the given I<ctx> or clears it if the I<ref> argument is NULL.
539According to RFC 4210 section 5.1.1, if no value for the sender field in
540CMP message headers can be determined (i.e., no CMP signer certificate
541and no subject DN is set via OSSL_CMP_CTX_set1_subjectName()
542then the sender field will contain the NULL-DN
543and the senderKID field of the CMP message header must be set.
544When signature-based protection is used the senderKID will be set to
545the subjectKeyIdentifier of the CMP signer certificate as far as present.
546If not present or when MAC-based protection is used
547the I<ref> value is taken as the fallback value for the senderKID.
548
549OSSL_CMP_CTX_set1_recipient() sets the recipient name that will be used in the
550PKIHeader of CMP request messages, i.e. the X509 name of the (CA) server.
551
552The recipient field in the header of a CMP message is mandatory.
553If not given explicitly the recipient is determined in the following order:
554the subject of the CMP server certificate set using OSSL_CMP_CTX_set1_srvCert(),
555the value set using OSSL_CMP_CTX_set1_issuer(),
556the issuer of the certificate set using OSSL_CMP_CTX_set1_oldCert(),
557the issuer of the CMP signer certificate,
558as far as any of those is present, else the NULL-DN as last resort.
559
560OSSL_CMP_CTX_push0_geninfo_ITAV() adds I<itav> to the stack in the I<ctx> to be
561added to the generalInfo field of the CMP PKIMessage header of a request
562message sent with this context.
563
564OSSL_CMP_CTX_reset_geninfo_ITAVs()
565clears any ITAVs that were added by OSSL_CMP_CTX_push0_geninfo_ITAV().
566
567OSSL_CMP_CTX_get0_geninfo_ITAVs() returns the list of ITAVs set in I<ctx>
568for inclusion in the generalInfo field of the CMP PKIMessage header of requests
569or NULL if not set.
570
571OSSL_CMP_CTX_set1_extraCertsOut() sets the stack of extraCerts that will be
572sent to remote.
573
574OSSL_CMP_CTX_set0_newPkey() can be used to explicitly set the given EVP_PKEY
575structure as the private or public key to be certified in the CMP context.
576The I<priv> parameter must be 0 if and only if the given key is a public key.
577
578OSSL_CMP_CTX_get0_newPkey() gives the key to use for certificate enrollment
579dependent on fields of the CMP context structure:
580the newPkey (which may be a private or public key) if present,
581else the public key in the p10CSR if present, else the client's private key.
582If the I<priv> parameter is not 0 and the selected key does not have a
583private component then NULL is returned.
584
585OSSL_CMP_CTX_set1_issuer() sets the name of the intended issuer that
586will be set in the CertTemplate, i.e., the X509 name of the CA server.
587
588OSSL_CMP_CTX_set1_serialNumber() sets the serial number optionally used to
589select the certificate to be revoked in Revocation Requests (RR).
590
591OSSL_CMP_CTX_set1_subjectName() sets the subject DN that will be used in
592the CertTemplate structure when requesting a new cert. For Key Update Requests
593(KUR), it defaults to the subject DN of the reference certificate,
594see OSSL_CMP_CTX_set1_oldCert(). This default is used for Initialization
595Requests (IR) and Certification Requests (CR) only if no SANs are set.
596The I<subjectName> is also used as fallback for the sender field
597of outgoing CMP messages if no reference certificate is available.
598
599OSSL_CMP_CTX_push1_subjectAltName() adds the given X509 name to the list of
600alternate names on the certificate template request. This cannot be used if
601any Subject Alternative Name extension is set via
602OSSL_CMP_CTX_set0_reqExtensions().
603By default, unless B<OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT> has been set,
604the Subject Alternative Names are copied from the reference certificate,
605see OSSL_CMP_CTX_set1_oldCert().
606If set and the subject DN is not set with OSSL_CMP_CTX_set1_subjectName() then
607the certificate template of an IR and CR will not be filled with the default
608subject DN from the reference certificate.
609If a subject DN is desired it needs to be set explicitly with
610OSSL_CMP_CTX_set1_subjectName().
611
612OSSL_CMP_CTX_set0_reqExtensions() sets the X.509v3 extensions to be used in
613IR/CR/KUR.
614
615OSSL_CMP_CTX_reqExtensions_have_SAN() returns 1 if the context contains
616a Subject Alternative Name extension, else 0 or -1 on error.
617
618OSSL_CMP_CTX_push0_policy() adds the certificate policy info object
619to the X509_EXTENSIONS of the requested certificate template.
620
621OSSL_CMP_CTX_set1_oldCert() sets the old certificate to be updated in
622Key Update Requests (KUR) or to be revoked in Revocation Requests (RR).
623For RR, this is ignored if an issuer name and a serial number are provided using
624OSSL_CMP_CTX_set1_issuer() and OSSL_CMP_CTX_set1_serialNumber(), respectively.
625For IR/CR/KUR this sets the I<reference certificate>,
626which otherwise defaults to the CMP signer certificate.
627The I<reference certificate> determined this way, if any, is used for providing
628default public key, subject DN, Subject Alternative Names, and issuer DN entries
629in the requested certificate template of IR/CR/KUR messages.
630
631The subject of the reference certificate is used as the sender field value
632in CMP message headers.
633Its issuer is used as default recipient in CMP message headers.
634
635OSSL_CMP_CTX_set1_p10CSR() sets the PKCS#10 CSR to use in P10CR messages.
636If such a CSR is provided, its subject and public key fields are also
637used as fallback values for the certificate template of IR/CR/KUR/RR messages,
638and any extensions included are added to the template of IR/CR/KUR messages.
639
640OSSL_CMP_CTX_push0_genm_ITAV() adds I<itav> to the stack in the I<ctx> which
641will be the body of a General Message sent with this context.
642
643OSSL_CMP_certConf_cb() is the default certificate confirmation callback function.
644If the callback argument is not NULL it must point to a trust store.
645In this case the function checks that the newly enrolled certificate can be
646verified using this trust store and untrusted certificates from the I<ctx>,
647which have been augmented by the list of extraCerts received.
648During this verification, any certificate status checking is disabled.
649If the callback argument is NULL the function tries building an approximate
650chain as far as possible using the same untrusted certificates from the I<ctx>,
651and if this fails it takes the received extraCerts as fallback.
652The resulting cert chain can be retrieved using OSSL_CMP_CTX_get1_newChain().
653This chain excludes the leaf certificate, i.e., the newly enrolled certificate.
654Also the trust anchor (the root certificate) is not included.
655
656OSSL_CMP_CTX_set_certConf_cb() sets the callback used for evaluating the newly
657enrolled certificate before the library sends, depending on its result,
658a positive or negative certConf message to the server. The callback has type
659
660 typedef int (*OSSL_CMP_certConf_cb_t) (OSSL_CMP_CTX *ctx, X509 *cert,
661                                        int fail_info, const char **txt);
662
663and should inspect the certificate it obtains via the I<cert> parameter and may
664overrule the pre-decision given in the I<fail_info> and I<*txt> parameters.
665If it accepts the certificate it must return 0, indicating success. Else it must
666return a bit field reflecting PKIFailureInfo with at least one failure bit and
667may set the I<*txt> output parameter to point to a string constant with more
668detail.  The transfer callback may make use of a custom defined argument stored
669in the I<ctx> by means of OSSL_CMP_CTX_set_certConf_cb_arg(), which may be
670retrieved again through OSSL_CMP_CTX_get_certConf_cb_arg().
671Typically, the callback will check at least that the certificate can be verified
672using a set of trusted certificates.
673It also could compare the subject DN and other fields of the newly
674enrolled certificate with the certificate template of the request.
675
676OSSL_CMP_CTX_set_certConf_cb_arg() sets an argument, respectively a pointer to a
677structure containing arguments, optionally to be used by the certConf callback.
678I<arg> is not consumed, and it must therefore explicitly be freed when not
679needed any more. I<arg> may be NULL to clear the entry.
680
681OSSL_CMP_CTX_get_certConf_cb_arg() gets the argument, respectively the pointer
682to a structure containing arguments, previously set by
683OSSL_CMP_CTX_set_certConf_cb_arg(), or NULL if unset.
684
685OSSL_CMP_CTX_get_status() returns for client contexts the PKIstatus from
686the last received CertRepMessage or Revocation Response or error message:
687=item B<OSSL_CMP_PKISTATUS_accepted> on successful receipt of a GENP message:
688
689=over 4
690
691=item B<OSSL_CMP_PKISTATUS_request>
692
693if an IR/CR/KUR/RR/GENM request message could not be produced,
694
695=item B<OSSL_CMP_PKISTATUS_trans>
696
697on a transmission error or transaction error for this type of request, and
698
699=item B<OSSL_CMP_PKISTATUS_unspecified>
700
701if no such request was attempted or OSSL_CMP_CTX_reinit() has been called.
702
703=back
704
705For server contexts it returns
706B<OSSL_CMP_PKISTATUS_trans> if a transaction is open,
707otherwise B<OSSL_CMP_PKISTATUS_unspecified>.
708
709OSSL_CMP_CTX_get0_statusString() returns the statusString from the last received
710CertRepMessage or Revocation Response or error message, or NULL if unset.
711
712OSSL_CMP_CTX_get_failInfoCode() returns the error code from the failInfo field
713of the last received CertRepMessage or Revocation Response or error message,
714or -1 if no such response was received or OSSL_CMP_CTX_reinit() has been called.
715This is a bit field and the flags for it are specified in the header file
716F<< <openssl/cmp.h> >>.
717The flags start with OSSL_CMP_CTX_FAILINFO, for example:
718OSSL_CMP_CTX_FAILINFO_badAlg. Returns -1 if the failInfoCode field is unset.
719
720OSSL_CMP_CTX_get0_validatedSrvCert() returns
721the successfully validated certificate, if any, that the CMP server used
722in the current transaction for signature-based response message protection,
723or NULL if the server used MAC-based protection.
724The value is relevant only at the end of a successful transaction.
725It may be used to check the authorization of the server based on its cert.
726
727OSSL_CMP_CTX_get0_newCert() returns the pointer to the newly obtained
728certificate in case it is available, else NULL.
729
730OSSL_CMP_CTX_get1_newChain() returns a pointer to a duplicate of the stack of
731X.509 certificates computed by OSSL_CMP_certConf_cb() (if this function has
732been called) on the last received certificate response message IP/CP/KUP.
733
734OSSL_CMP_CTX_get1_caPubs() returns a pointer to a duplicate of the list of
735X.509 certificates in the caPubs field of the last received certificate
736response message (of type IP, CP, or KUP),
737or an empty stack if no caPubs have been received in the current transaction.
738
739OSSL_CMP_CTX_get1_extraCertsIn() returns a pointer to a duplicate of the list
740of X.509 certificates contained in the extraCerts field of the last received
741response message (except for pollRep and PKIConf), or
742an empty stack if no extraCerts have been received in the current transaction.
743
744OSSL_CMP_CTX_set1_transactionID() sets the given transaction ID in the given
745OSSL_CMP_CTX structure.
746
747OSSL_CMP_CTX_set1_senderNonce() stores the last sent sender I<nonce> in
748the I<ctx>. This will be used to validate the recipNonce in incoming messages.
749
750=head1 NOTES
751
752CMP is defined in RFC 4210 (and CRMF in RFC 4211).
753
754=head1 RETURN VALUES
755
756OSSL_CMP_CTX_free() and OSSL_CMP_CTX_print_errors() do not return anything.
757
758OSSL_CMP_CTX_new(),
759OSSL_CMP_CTX_get0_libctx(), OSSL_CMP_CTX_get0_propq(),
760OSSL_CMP_CTX_get_http_cb_arg(),
761OSSL_CMP_CTX_get_transfer_cb_arg(),
762OSSL_CMP_CTX_get0_trusted(),
763OSSL_CMP_CTX_get0_untrusted(),
764OSSL_CMP_CTX_get0_geninfo_ITAVs(),
765OSSL_CMP_CTX_get0_newPkey(),
766OSSL_CMP_CTX_get_certConf_cb_arg(),
767OSSL_CMP_CTX_get0_statusString(),
768OSSL_CMP_CTX_get0_validatedSrvCert(),
769OSSL_CMP_CTX_get0_newCert(),
770OSSL_CMP_CTX_get0_newChain(),
771OSSL_CMP_CTX_get1_caPubs(), and
772OSSL_CMP_CTX_get1_extraCertsIn()
773return the intended pointer value as described above or NULL on error.
774
775OSSL_CMP_CTX_get_option(),
776OSSL_CMP_CTX_reqExtensions_have_SAN(),
777OSSL_CMP_CTX_get_status(), and
778OSSL_CMP_CTX_get_failInfoCode()
779return the intended value as described above or -1 on error.
780
781OSSL_CMP_certConf_cb() returns I<fail_info> if it is not equal to 0,
782else 0 on successful validation,
783or else a bit field with the B<OSSL_CMP_PKIFAILUREINFO_incorrectData> bit set.
784
785All other functions, including OSSL_CMP_CTX_reinit()
786and OSSL_CMP_CTX_reset_geninfo_ITAVs(),
787return 1 on success, 0 on error.
788
789=head1 EXAMPLES
790
791The following code omits error handling.
792
793Set up a CMP client context for sending requests and verifying responses:
794
795    cmp_ctx = OSSL_CMP_CTX_new();
796    OSSL_CMP_CTX_set1_server(cmp_ctx, name_or_address);
797    OSSL_CMP_CTX_set1_serverPort(cmp_ctx, port_string);
798    OSSL_CMP_CTX_set1_serverPath(cmp_ctx, path_or_alias);
799    OSSL_CMP_CTX_set0_trusted(cmp_ctx, ts);
800
801Set up symmetric credentials for MAC-based message protection such as PBM:
802
803    OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, ref, ref_len);
804    OSSL_CMP_CTX_set1_secretValue(cmp_ctx, sec, sec_len);
805
806Set up the details for certificate requests:
807
808    OSSL_CMP_CTX_set1_subjectName(cmp_ctx, name);
809    OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, initialKey);
810
811Perform an Initialization Request transaction:
812
813    initialCert = OSSL_CMP_exec_IR_ses(cmp_ctx);
814
815Reset the transaction state of the CMP context and the credentials:
816
817    OSSL_CMP_CTX_reinit(cmp_ctx);
818    OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, NULL, 0);
819    OSSL_CMP_CTX_set1_secretValue(cmp_ctx, NULL, 0);
820
821Perform a Certification Request transaction, making use of the new credentials:
822
823    OSSL_CMP_CTX_set1_cert(cmp_ctx, initialCert);
824    OSSL_CMP_CTX_set1_pkey(cmp_ctx, initialKey);
825    OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, curentKey);
826    currentCert = OSSL_CMP_exec_CR_ses(cmp_ctx);
827
828Perform a Key Update Request, signed using the cert (and key) to be updated:
829
830    OSSL_CMP_CTX_reinit(cmp_ctx);
831    OSSL_CMP_CTX_set1_cert(cmp_ctx, currentCert);
832    OSSL_CMP_CTX_set1_pkey(cmp_ctx, currentKey);
833    OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, updatedKey);
834    currentCert = OSSL_CMP_exec_KUR_ses(cmp_ctx);
835    currentKey = updatedKey;
836
837Perform a General Message transaction including, as an example,
838the id-it-signKeyPairTypes OID and prints info on the General Response contents:
839
840    OSSL_CMP_CTX_reinit(cmp_ctx);
841
842    ASN1_OBJECT *type = OBJ_txt2obj("1.3.6.1.5.5.7.4.2", 1);
843    OSSL_CMP_ITAV *itav = OSSL_CMP_ITAV_create(type, NULL);
844    OSSL_CMP_CTX_push0_genm_ITAV(cmp_ctx, itav);
845
846    STACK_OF(OSSL_CMP_ITAV) *itavs;
847    itavs = OSSL_CMP_exec_GENM_ses(cmp_ctx);
848    print_itavs(itavs);
849    sk_OSSL_CMP_ITAV_pop_free(itavs, OSSL_CMP_ITAV_free);
850
851=head1 SEE ALSO
852
853L<OSSL_CMP_exec_IR_ses(3)>, L<OSSL_CMP_exec_CR_ses(3)>,
854L<OSSL_CMP_exec_KUR_ses(3)>, L<OSSL_CMP_exec_GENM_ses(3)>,
855L<OSSL_CMP_exec_certreq(3)>, L<OSSL_CMP_MSG_http_perform(3)>,
856L<ERR_print_errors_cb(3)>, L<OSSL_HTTP_open(3)>
857
858=head1 HISTORY
859
860The OpenSSL CMP support was added in OpenSSL 3.0.
861
862OSSL_CMP_CTX_get0_trustedStore() was renamed to OSSL_CMP_CTX_get0_trusted() and
863OSSL_CMP_CTX_set0_trustedStore() was renamed to OSSL_CMP_CTX_set0_trusted(),
864using macros, while keeping the old names for backward compatibility,
865in OpenSSL 3.2.
866
867OSSL_CMP_CTX_reset_geninfo_ITAVs() was added in OpenSSL 3.0.8.
868
869OSSL_CMP_CTX_set1_serialNumber(),
870OSSL_CMP_CTX_get0_libctx(), OSSL_CMP_CTX_get0_propq(), and
871OSSL_CMP_CTX_get0_validatedSrvCert() were added in OpenSSL 3.2.
872
873OSSL_CMP_CTX_get0_geninfo_ITAVs() was added in OpenSSL 3.3.
874
875=head1 COPYRIGHT
876
877Copyright 2007-2024 The OpenSSL Project Authors. All Rights Reserved.
878
879Licensed under the Apache License 2.0 (the "License").  You may not use
880this file except in compliance with the License.  You can obtain a copy
881in the file LICENSE in the source distribution or at
882L<https://www.openssl.org/source/license.html>.
883
884=cut
885