1=pod 2 3=head1 NAME 4 5OSSL_CMP_CTX_new, 6OSSL_CMP_CTX_free, 7OSSL_CMP_CTX_reinit, 8OSSL_CMP_CTX_set_option, 9OSSL_CMP_CTX_get_option, 10OSSL_CMP_CTX_set_log_cb, 11OSSL_CMP_CTX_set_log_verbosity, 12OSSL_CMP_CTX_print_errors, 13OSSL_CMP_CTX_set1_serverPath, 14OSSL_CMP_CTX_set1_server, 15OSSL_CMP_CTX_set_serverPort, 16OSSL_CMP_CTX_set1_proxy, 17OSSL_CMP_CTX_set1_no_proxy, 18OSSL_CMP_CTX_set_http_cb, 19OSSL_CMP_CTX_set_http_cb_arg, 20OSSL_CMP_CTX_get_http_cb_arg, 21OSSL_CMP_transfer_cb_t, 22OSSL_CMP_CTX_set_transfer_cb, 23OSSL_CMP_CTX_set_transfer_cb_arg, 24OSSL_CMP_CTX_get_transfer_cb_arg, 25OSSL_CMP_CTX_set1_srvCert, 26OSSL_CMP_CTX_set1_expected_sender, 27OSSL_CMP_CTX_set0_trustedStore, 28OSSL_CMP_CTX_get0_trustedStore, 29OSSL_CMP_CTX_set1_untrusted, 30OSSL_CMP_CTX_get0_untrusted, 31OSSL_CMP_CTX_set1_cert, 32OSSL_CMP_CTX_build_cert_chain, 33OSSL_CMP_CTX_set1_pkey, 34OSSL_CMP_CTX_set1_referenceValue, 35OSSL_CMP_CTX_set1_secretValue, 36OSSL_CMP_CTX_set1_recipient, 37OSSL_CMP_CTX_push0_geninfo_ITAV, 38OSSL_CMP_CTX_reset_geninfo_ITAVs, 39OSSL_CMP_CTX_set1_extraCertsOut, 40OSSL_CMP_CTX_set0_newPkey, 41OSSL_CMP_CTX_get0_newPkey, 42OSSL_CMP_CTX_set1_issuer, 43OSSL_CMP_CTX_set1_subjectName, 44OSSL_CMP_CTX_push1_subjectAltName, 45OSSL_CMP_CTX_set0_reqExtensions, 46OSSL_CMP_CTX_reqExtensions_have_SAN, 47OSSL_CMP_CTX_push0_policy, 48OSSL_CMP_CTX_set1_oldCert, 49OSSL_CMP_CTX_set1_p10CSR, 50OSSL_CMP_CTX_push0_genm_ITAV, 51OSSL_CMP_certConf_cb_t, 52OSSL_CMP_certConf_cb, 53OSSL_CMP_CTX_set_certConf_cb, 54OSSL_CMP_CTX_set_certConf_cb_arg, 55OSSL_CMP_CTX_get_certConf_cb_arg, 56OSSL_CMP_CTX_get_status, 57OSSL_CMP_CTX_get0_statusString, 58OSSL_CMP_CTX_get_failInfoCode, 59OSSL_CMP_CTX_get0_newCert, 60OSSL_CMP_CTX_get1_newChain, 61OSSL_CMP_CTX_get1_caPubs, 62OSSL_CMP_CTX_get1_extraCertsIn, 63OSSL_CMP_CTX_set1_transactionID, 64OSSL_CMP_CTX_set1_senderNonce 65- functions for managing the CMP client context data structure 66 67=head1 SYNOPSIS 68 69 #include <openssl/cmp.h> 70 71 OSSL_CMP_CTX *OSSL_CMP_CTX_new(OSSL_LIB_CTX *libctx, const char *propq); 72 void OSSL_CMP_CTX_free(OSSL_CMP_CTX *ctx); 73 int OSSL_CMP_CTX_reinit(OSSL_CMP_CTX *ctx); 74 int OSSL_CMP_CTX_set_option(OSSL_CMP_CTX *ctx, int opt, int val); 75 int OSSL_CMP_CTX_get_option(const OSSL_CMP_CTX *ctx, int opt); 76 77 /* logging and error reporting: */ 78 int OSSL_CMP_CTX_set_log_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_log_cb_t cb); 79 #define OSSL_CMP_CTX_set_log_verbosity(ctx, level) 80 void OSSL_CMP_CTX_print_errors(const OSSL_CMP_CTX *ctx); 81 82 /* message transfer: */ 83 int OSSL_CMP_CTX_set1_serverPath(OSSL_CMP_CTX *ctx, const char *path); 84 int OSSL_CMP_CTX_set1_server(OSSL_CMP_CTX *ctx, const char *address); 85 int OSSL_CMP_CTX_set_serverPort(OSSL_CMP_CTX *ctx, int port); 86 int OSSL_CMP_CTX_set1_proxy(OSSL_CMP_CTX *ctx, const char *name); 87 int OSSL_CMP_CTX_set1_no_proxy(OSSL_CMP_CTX *ctx, const char *names); 88 int OSSL_CMP_CTX_set_http_cb(OSSL_CMP_CTX *ctx, HTTP_bio_cb_t cb); 89 int OSSL_CMP_CTX_set_http_cb_arg(OSSL_CMP_CTX *ctx, void *arg); 90 void *OSSL_CMP_CTX_get_http_cb_arg(const OSSL_CMP_CTX *ctx); 91 typedef OSSL_CMP_MSG *(*OSSL_CMP_transfer_cb_t)(OSSL_CMP_CTX *ctx, 92 const OSSL_CMP_MSG *req); 93 int OSSL_CMP_CTX_set_transfer_cb(OSSL_CMP_CTX *ctx, 94 OSSL_CMP_transfer_cb_t cb); 95 int OSSL_CMP_CTX_set_transfer_cb_arg(OSSL_CMP_CTX *ctx, void *arg); 96 void *OSSL_CMP_CTX_get_transfer_cb_arg(const OSSL_CMP_CTX *ctx); 97 98 /* server authentication: */ 99 int OSSL_CMP_CTX_set1_srvCert(OSSL_CMP_CTX *ctx, X509 *cert); 100 int OSSL_CMP_CTX_set1_expected_sender(OSSL_CMP_CTX *ctx, 101 const X509_NAME *name); 102 int OSSL_CMP_CTX_set0_trustedStore(OSSL_CMP_CTX *ctx, X509_STORE *store); 103 X509_STORE *OSSL_CMP_CTX_get0_trustedStore(const OSSL_CMP_CTX *ctx); 104 int OSSL_CMP_CTX_set1_untrusted(OSSL_CMP_CTX *ctx, STACK_OF(X509) *certs); 105 STACK_OF(X509) *OSSL_CMP_CTX_get0_untrusted(const OSSL_CMP_CTX *ctx); 106 107 /* client authentication: */ 108 int OSSL_CMP_CTX_set1_cert(OSSL_CMP_CTX *ctx, X509 *cert); 109 int OSSL_CMP_CTX_build_cert_chain(OSSL_CMP_CTX *ctx, X509_STORE *own_trusted, 110 STACK_OF(X509) *candidates); 111 int OSSL_CMP_CTX_set1_pkey(OSSL_CMP_CTX *ctx, EVP_PKEY *pkey); 112 int OSSL_CMP_CTX_set1_referenceValue(OSSL_CMP_CTX *ctx, 113 const unsigned char *ref, int len); 114 int OSSL_CMP_CTX_set1_secretValue(OSSL_CMP_CTX *ctx, 115 const unsigned char *sec, int len); 116 117 /* CMP message header and extra certificates: */ 118 int OSSL_CMP_CTX_set1_recipient(OSSL_CMP_CTX *ctx, const X509_NAME *name); 119 int OSSL_CMP_CTX_push0_geninfo_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav); 120 int OSSL_CMP_CTX_reset_geninfo_ITAVs(OSSL_CMP_CTX *ctx); 121 int OSSL_CMP_CTX_set1_extraCertsOut(OSSL_CMP_CTX *ctx, 122 STACK_OF(X509) *extraCertsOut); 123 124 /* certificate template: */ 125 int OSSL_CMP_CTX_set0_newPkey(OSSL_CMP_CTX *ctx, int priv, EVP_PKEY *pkey); 126 EVP_PKEY *OSSL_CMP_CTX_get0_newPkey(const OSSL_CMP_CTX *ctx, int priv); 127 int OSSL_CMP_CTX_set1_issuer(OSSL_CMP_CTX *ctx, const X509_NAME *name); 128 int OSSL_CMP_CTX_set1_subjectName(OSSL_CMP_CTX *ctx, const X509_NAME *name); 129 int OSSL_CMP_CTX_push1_subjectAltName(OSSL_CMP_CTX *ctx, 130 const GENERAL_NAME *name); 131 int OSSL_CMP_CTX_set0_reqExtensions(OSSL_CMP_CTX *ctx, X509_EXTENSIONS *exts); 132 int OSSL_CMP_CTX_reqExtensions_have_SAN(OSSL_CMP_CTX *ctx); 133 int OSSL_CMP_CTX_push0_policy(OSSL_CMP_CTX *ctx, POLICYINFO *pinfo); 134 int OSSL_CMP_CTX_set1_oldCert(OSSL_CMP_CTX *ctx, X509 *cert); 135 int OSSL_CMP_CTX_set1_p10CSR(OSSL_CMP_CTX *ctx, const X509_REQ *csr); 136 137 /* misc body contents: */ 138 int OSSL_CMP_CTX_push0_genm_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav); 139 140 /* certificate confirmation: */ 141 typedef int (*OSSL_CMP_certConf_cb_t)(OSSL_CMP_CTX *ctx, X509 *cert, 142 int fail_info, const char **txt); 143 int OSSL_CMP_certConf_cb(OSSL_CMP_CTX *ctx, X509 *cert, int fail_info, 144 const char **text); 145 int OSSL_CMP_CTX_set_certConf_cb(OSSL_CMP_CTX *ctx, OSSL_CMP_certConf_cb_t cb); 146 int OSSL_CMP_CTX_set_certConf_cb_arg(OSSL_CMP_CTX *ctx, void *arg); 147 void *OSSL_CMP_CTX_get_certConf_cb_arg(const OSSL_CMP_CTX *ctx); 148 149 /* result fetching: */ 150 int OSSL_CMP_CTX_get_status(const OSSL_CMP_CTX *ctx); 151 OSSL_CMP_PKIFREETEXT *OSSL_CMP_CTX_get0_statusString(const OSSL_CMP_CTX *ctx); 152 int OSSL_CMP_CTX_get_failInfoCode(const OSSL_CMP_CTX *ctx); 153 154 X509 *OSSL_CMP_CTX_get0_newCert(const OSSL_CMP_CTX *ctx); 155 STACK_OF(X509) *OSSL_CMP_CTX_get1_newChain(const OSSL_CMP_CTX *ctx); 156 STACK_OF(X509) *OSSL_CMP_CTX_get1_caPubs(const OSSL_CMP_CTX *ctx); 157 STACK_OF(X509) *OSSL_CMP_CTX_get1_extraCertsIn(const OSSL_CMP_CTX *ctx); 158 159 /* for testing and debugging purposes: */ 160 int OSSL_CMP_CTX_set1_transactionID(OSSL_CMP_CTX *ctx, 161 const ASN1_OCTET_STRING *id); 162 int OSSL_CMP_CTX_set1_senderNonce(OSSL_CMP_CTX *ctx, 163 const ASN1_OCTET_STRING *nonce); 164 165=head1 DESCRIPTION 166 167This is the context API for using CMP (Certificate Management Protocol) with 168OpenSSL. 169 170OSSL_CMP_CTX_new() allocates an B<OSSL_CMP_CTX> structure associated with 171the library context I<libctx> and property query string I<propq>, 172both of which may be NULL to select the defaults. 173It initializes the remaining fields to their default values - for instance, 174the logging verbosity is set to OSSL_CMP_LOG_INFO, 175the message timeout is set to 120 seconds, 176and the proof-of-possession method is set to OSSL_CRMF_POPO_SIGNATURE. 177 178OSSL_CMP_CTX_free() deallocates an OSSL_CMP_CTX structure. 179 180OSSL_CMP_CTX_reinit() prepares the given I<ctx> for a further transaction by 181clearing the internal CMP transaction (aka session) status, PKIStatusInfo, 182and any previous results (newCert, newChain, caPubs, and extraCertsIn) 183from the last executed transaction. 184It also clears any ITAVs that were added by OSSL_CMP_CTX_push0_genm_ITAV(). 185All other field values (i.e., CMP options) are retained for potential reuse. 186 187OSSL_CMP_CTX_set_option() sets the given value for the given option 188(e.g., OSSL_CMP_OPT_IMPLICIT_CONFIRM) in the given OSSL_CMP_CTX structure. 189 190The following options can be set: 191 192=over 4 193 194=item B<OSSL_CMP_OPT_LOG_VERBOSITY> 195 196 The level of severity needed for actually outputting log messages 197 due to errors, warnings, general info, debugging, etc. 198 Default is OSSL_CMP_LOG_INFO. See also L<OSSL_CMP_log_open(3)>. 199 200=item B<OSSL_CMP_OPT_KEEP_ALIVE> 201 202 If the given value is 0 then HTTP connections are not kept open 203 after receiving a response, which is the default behavior for HTTP 1.0. 204 If the value is 1 or 2 then persistent connections are requested. 205 If the value is 2 then persistent connections are required, 206 i.e., in case the server does not grant them an error occurs. 207 The default value is 1: prefer to keep the connection open. 208 209=item B<OSSL_CMP_OPT_MSG_TIMEOUT> 210 211 Number of seconds a CMP request-response message round trip 212 is allowed to take before a timeout error is returned. 213 A value <= 0 means no limitation (waiting indefinitely). 214 Default is to use the B<OSSL_CMP_OPT_TOTAL_TIMEOUT> setting. 215 216=item B<OSSL_CMP_OPT_TOTAL_TIMEOUT> 217 218 Maximum total number of seconds a transaction may take, 219 including polling etc. 220 A value <= 0 means no limitation (waiting indefinitely). 221 Default is 0. 222 223=item B<OSSL_CMP_OPT_VALIDITY_DAYS> 224 225 Number of days new certificates are asked to be valid for. 226 227=item B<OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT> 228 229 Do not take default Subject Alternative Names 230 from the reference certificate. 231 232=item B<OSSL_CMP_OPT_SUBJECTALTNAME_CRITICAL> 233 234 Demand that the given Subject Alternative Names are flagged as critical. 235 236=item B<OSSL_CMP_OPT_POLICIES_CRITICAL> 237 238 Demand that the given policies are flagged as critical. 239 240=item B<OSSL_CMP_OPT_POPO_METHOD> 241 242 Select the proof of possession method to use. Possible values are: 243 244 OSSL_CRMF_POPO_NONE - ProofOfPossession field omitted 245 OSSL_CRMF_POPO_RAVERIFIED - assert that the RA has already 246 verified the PoPo 247 OSSL_CRMF_POPO_SIGNATURE - sign a value with private key, 248 which is the default. 249 OSSL_CRMF_POPO_KEYENC - decrypt the encrypted certificate 250 ("indirect method") 251 252 Note that a signature-based POPO can only be produced if a private key 253 is provided as the newPkey or client's pkey component of the CMP context. 254 255=item B<OSSL_CMP_OPT_DIGEST_ALGNID> 256 257 The NID of the digest algorithm to be used in RFC 4210's MSG_SIG_ALG 258 for signature-based message protection and Proof-of-Possession (POPO). 259 Default is SHA256. 260 261=item B<OSSL_CMP_OPT_OWF_ALGNID> 262 The NID of the digest algorithm to be used as one-way function (OWF) 263 for MAC-based message protection with password-based MAC (PBM). 264 See RFC 4210 section 5.1.3.1 for details. 265 Default is SHA256. 266 267=item B<OSSL_CMP_OPT_MAC_ALGNID> 268 The NID of the MAC algorithm to be used for message protection with PBM. 269 Default is HMAC-SHA1 as per RFC 4210. 270 271=item B<OSSL_CMP_OPT_REVOCATION_REASON> 272 273 The reason code to be included in a Revocation Request (RR); 274 values: 0..10 (RFC 5210, 5.3.1) or -1 for none, which is the default. 275 276=item B<OSSL_CMP_OPT_IMPLICIT_CONFIRM> 277 278 Request server to enable implicit confirm mode, where the client 279 does not need to send confirmation upon receiving the 280 certificate. If the server does not enable implicit confirmation 281 in the return message, then confirmation is sent anyway. 282 283=item B<OSSL_CMP_OPT_DISABLE_CONFIRM> 284 285 Do not confirm enrolled certificates, to cope with broken servers 286 not supporting implicit confirmation correctly. 287B<WARNING:> This setting leads to unspecified behavior and it is meant 288exclusively to allow interoperability with server implementations violating 289RFC 4210. 290 291=item B<OSSL_CMP_OPT_UNPROTECTED_SEND> 292 293 Send request or response messages without CMP-level protection. 294 295=item B<OSSL_CMP_OPT_UNPROTECTED_ERRORS> 296 297 Accept unprotected error responses which are either explicitly 298 unprotected or where protection verification failed. Applies to regular 299 error messages as well as certificate responses (IP/CP/KUP) and 300 revocation responses (RP) with rejection. 301B<WARNING:> This setting leads to unspecified behavior and it is meant 302exclusively to allow interoperability with server implementations violating 303RFC 4210. 304 305=item B<OSSL_CMP_OPT_IGNORE_KEYUSAGE> 306 307 Ignore key usage restrictions in the signer's certificate when 308 validating signature-based protection in received CMP messages. 309 Else, 'digitalSignature' must be allowed by CMP signer certificates. 310 311=item B<OSSL_CMP_OPT_PERMIT_TA_IN_EXTRACERTS_FOR_IR> 312 313 Allow retrieving a trust anchor from extraCerts and using that 314 to validate the certificate chain of an IP message. 315 316=back 317 318OSSL_CMP_CTX_get_option() reads the current value of the given option 319(e.g., OSSL_CMP_OPT_IMPLICIT_CONFIRM) from the given OSSL_CMP_CTX structure. 320 321OSSL_CMP_CTX_set_log_cb() sets in I<ctx> the callback function I<cb> 322for handling error queue entries and logging messages. 323When I<cb> is NULL errors are printed to STDERR (if available, else ignored) 324any log messages are ignored. 325Alternatively, L<OSSL_CMP_log_open(3)> may be used to direct logging to STDOUT. 326 327OSSL_CMP_CTX_set_log_verbosity() is a macro setting the 328OSSL_CMP_OPT_LOG_VERBOSITY context option to the given level. 329 330OSSL_CMP_CTX_print_errors() outputs any entries in the OpenSSL error queue. It 331is similar to L<ERR_print_errors_cb(3)> but uses the CMP log callback function 332if set in the I<ctx> for uniformity with CMP logging if given. Otherwise it uses 333L<ERR_print_errors(3)> to print to STDERR (unless OPENSSL_NO_STDIO is defined). 334 335OSSL_CMP_CTX_set1_serverPath() sets the HTTP path of the CMP server on the host, 336also known as "CMP alias". 337The default is C</>. 338 339OSSL_CMP_CTX_set1_server() sets the given server I<address> 340(which may be a hostname or IP address or NULL) in the given I<ctx>. 341 342OSSL_CMP_CTX_set_serverPort() sets the port of the CMP server to connect to. 343If not used or the I<port> argument is 0 344the default port applies, which is 80 for HTTP and 443 for HTTPS. 345 346OSSL_CMP_CTX_set1_proxy() sets the HTTP proxy to be used for connecting to 347the given CMP server unless overruled by any "no_proxy" settings (see below). 348If TLS is not used this defaults to the value of 349the environment variable C<http_proxy> if set, else C<HTTP_PROXY>. 350Otherwise defaults to the value of C<https_proxy> if set, else C<HTTPS_PROXY>. 351An empty proxy string specifies not to use a proxy. 352Else the format is C<[http[s]://]address[:port][/path]>, 353where any path given is ignored. 354The default port number is 80, or 443 in case C<https:> is given. 355 356OSSL_CMP_CTX_set1_no_proxy() sets the list of server hostnames not to use 357an HTTP proxy for. The names may be separated by commas and/or whitespace. 358Defaults to the environment variable C<no_proxy> if set, else C<NO_PROXY>. 359 360OSSL_CMP_CTX_set_http_cb() sets the optional BIO connect/disconnect callback 361function, which has the prototype 362 363 typedef BIO *(*HTTP_bio_cb_t) (BIO *bio, void *ctx, int connect, int detail); 364 365The callback may modify the I<bio> provided by L<OSSL_CMP_MSG_http_perform(3)>, 366whereby it may make use of a custom defined argument I<ctx> 367stored in the OSSL_CMP_CTX by means of OSSL_CMP_CTX_set_http_cb_arg(). 368During connection establishment, just after calling BIO_do_connect_retry(), 369the function is invoked with the I<connect> argument being 1 and the I<detail> 370argument being 1 if HTTPS is requested, i.e., SSL/TLS should be enabled. On 371disconnect I<connect> is 0 and I<detail> is 1 in case no error occurred, else 0. 372For instance, on connect the function may prepend a TLS BIO to implement HTTPS; 373after disconnect it may do some diagnostic output and/or specific cleanup. 374The function should return NULL to indicate failure. 375After disconnect the modified BIO will be deallocated using BIO_free_all(). 376 377OSSL_CMP_CTX_set_http_cb_arg() sets an argument, respectively a pointer to 378a structure containing arguments, 379optionally to be used by the http connect/disconnect callback function. 380I<arg> is not consumed, and it must therefore explicitly be freed when not 381needed any more. I<arg> may be NULL to clear the entry. 382 383OSSL_CMP_CTX_get_http_cb_arg() gets the argument, respectively the pointer to a 384structure containing arguments, previously set by 385OSSL_CMP_CTX_set_http_cb_arg() or NULL if unset. 386 387OSSL_CMP_CTX_set_transfer_cb() sets the message transfer callback function, 388which has the type 389 390 typedef OSSL_CMP_MSG *(*OSSL_CMP_transfer_cb_t) (OSSL_CMP_CTX *ctx, 391 const OSSL_CMP_MSG *req); 392 393Returns 1 on success, 0 on error. 394 395Default is NULL, which implies the use of L<OSSL_CMP_MSG_http_perform(3)>. 396The callback should send the CMP request message it obtains via the I<req> 397parameter and on success return the response, else it must return NULL. 398The transfer callback may make use of a custom defined argument stored in 399the ctx by means of OSSL_CMP_CTX_set_transfer_cb_arg(), which may be retrieved 400again through OSSL_CMP_CTX_get_transfer_cb_arg(). 401 402OSSL_CMP_CTX_set_transfer_cb_arg() sets an argument, respectively a pointer to a 403structure containing arguments, optionally to be used by the transfer callback. 404I<arg> is not consumed, and it must therefore explicitly be freed when not 405needed any more. I<arg> may be NULL to clear the entry. 406 407OSSL_CMP_CTX_get_transfer_cb_arg() gets the argument, respectively the pointer 408to a structure containing arguments, previously set by 409OSSL_CMP_CTX_set_transfer_cb_arg() or NULL if unset. 410 411OSSL_CMP_CTX_set1_srvCert() sets the expected server cert in I<ctx> and trusts 412it directly (even if it is expired) when verifying signed response messages. 413This pins the accepted CMP server and 414results in ignoring whatever may be set using OSSL_CMP_CTX_set0_trustedStore(). 415Any previously set value is freed. 416The I<cert> argument may be NULL to clear the entry. 417If set, the subject of the certificate is also used 418as default value for the recipient of CMP requests 419and as default value for the expected sender of CMP responses. 420 421OSSL_CMP_CTX_set1_expected_sender() sets the Distinguished Name (DN) 422expected in the sender field of incoming CMP messages. 423Defaults to the subject of the pinned server certificate, if any. 424This can be used to make sure that only a particular entity is accepted as 425CMP message signer, and attackers are not able to use arbitrary certificates 426of a trusted PKI hierarchy to fraudulently pose as CMP server. 427Note that this gives slightly more freedom than OSSL_CMP_CTX_set1_srvCert(), 428which pins the server to the holder of a particular certificate, while the 429expected sender name will continue to match after updates of the server cert. 430 431OSSL_CMP_CTX_set0_trustedStore() 432sets in the CMP context I<ctx> the certificate store of type X509_STORE 433containing trusted certificates, typically of root CAs. 434This is ignored when a certificate is pinned using OSSL_CMP_CTX_set1_srvCert(). 435The store may also hold CRLs and a certificate verification callback function 436used for signature-based peer authentication. 437Any store entry already set before is freed. 438When given a NULL parameter the entry is cleared. 439 440OSSL_CMP_CTX_get0_trustedStore() 441extracts from the CMP context I<ctx> the pointer to the currently set 442certificate store containing trust anchors etc., or an empty store if unset. 443 444OSSL_CMP_CTX_set1_untrusted() sets up a list of non-trusted certificates 445of intermediate CAs that may be useful for path construction for the own CMP 446signer certificate, for the own TLS certificate (if any), when verifying peer 447CMP protection certificates, and when verifying newly enrolled certificates. 448The reference counts of those certificates handled successfully are increased. 449 450OSSL_CMP_CTX_get0_untrusted(OSSL_CMP_CTX *ctx) returns a pointer to the 451list of untrusted certs, which may be empty if unset. 452 453OSSL_CMP_CTX_set1_cert() sets the CMP signer certificate, also called protection 454certificate, related to the private key for signature-based message protection. 455Therefore the public key of this I<cert> must correspond to 456the private key set before or thereafter via OSSL_CMP_CTX_set1_pkey(). 457When using signature-based protection of CMP request messages 458this CMP signer certificate will be included first in the extraCerts field. 459It serves as fallback reference certificate, see OSSL_CMP_CTX_set1_oldCert(). 460The subject of this I<cert> will be used as the sender field of outgoing 461messages, while the subject of any cert set via OSSL_CMP_CTX_set1_oldCert() 462and any value set via OSSL_CMP_CTX_set1_subjectName() are used as fallback. 463 464The I<cert> argument may be NULL to clear the entry. 465 466OSSL_CMP_CTX_build_cert_chain() builds a certificate chain for the CMP signer 467certificate previously set in the I<ctx>. It adds the optional I<candidates>, 468a list of intermediate CA certs that may already constitute the targeted chain, 469to the untrusted certs that may already exist in the I<ctx>. 470Then the function uses this augmented set of certs for chain construction. 471If I<own_trusted> is NULL it builds the chain as far down as possible and 472ignores any verification errors. Else the CMP signer certificate must be 473verifiable where the chain reaches a trust anchor contained in I<own_trusted>. 474On success the function stores the resulting chain in I<ctx> 475for inclusion in the extraCerts field of signature-protected messages. 476Calling this function is optional; by default a chain construction 477is performed on demand that is equivalent to calling this function 478with the I<candidates> and I<own_trusted> arguments being NULL. 479 480OSSL_CMP_CTX_set1_pkey() sets the client's private key corresponding to the 481CMP signer certificate set via OSSL_CMP_CTX_set1_cert(). 482This key is used create signature-based protection (protectionAlg = MSG_SIG_ALG) 483of outgoing messages 484unless a symmetric secret has been set via OSSL_CMP_CTX_set1_secretValue(). 485The I<pkey> argument may be NULL to clear the entry. 486 487OSSL_CMP_CTX_set1_secretValue() sets in I<ctx> the byte string I<sec> of length 488I<len> to use as pre-shared secret, or clears it if the I<sec> argument is NULL. 489If present, this secret is used to create MAC-based authentication and integrity 490protection (rather than applying signature-based protection) 491of outgoing messages and to verify authenticity and integrity of incoming 492messages that have MAC-based protection (protectionAlg = C<MSG_MAC_ALG>). 493 494OSSL_CMP_CTX_set1_referenceValue() sets the given referenceValue I<ref> with 495length I<len> in the given I<ctx> or clears it if the I<ref> argument is NULL. 496According to RFC 4210 section 5.1.1, if no value for the sender field in 497CMP message headers can be determined (i.e., no CMP signer certificate 498and no subject DN is set via OSSL_CMP_CTX_set1_subjectName() 499then the sender field will contain the NULL-DN 500and the senderKID field of the CMP message header must be set. 501When signature-based protection is used the senderKID will be set to 502the subjectKeyIdentifier of the CMP signer certificate as far as present. 503If not present or when MAC-based protection is used 504the I<ref> value is taken as the fallback value for the senderKID. 505 506OSSL_CMP_CTX_set1_recipient() sets the recipient name that will be used in the 507PKIHeader of CMP request messages, i.e. the X509 name of the (CA) server. 508 509The recipient field in the header of a CMP message is mandatory. 510If not given explicitly the recipient is determined in the following order: 511the subject of the CMP server certificate set using OSSL_CMP_CTX_set1_srvCert(), 512the value set using OSSL_CMP_CTX_set1_issuer(), 513the issuer of the certificate set using OSSL_CMP_CTX_set1_oldCert(), 514the issuer of the CMP signer certificate, 515as far as any of those is present, else the NULL-DN as last resort. 516 517OSSL_CMP_CTX_push0_geninfo_ITAV() adds I<itav> to the stack in the I<ctx> to be 518added to the GeneralInfo field of the CMP PKIMessage header of a request 519message sent with this context. 520 521OSSL_CMP_CTX_reset_geninfo_ITAVs() 522clears any ITAVs that were added by OSSL_CMP_CTX_push0_geninfo_ITAV(). 523 524OSSL_CMP_CTX_set1_extraCertsOut() sets the stack of extraCerts that will be 525sent to remote. 526 527OSSL_CMP_CTX_set0_newPkey() can be used to explicitly set the given EVP_PKEY 528structure as the private or public key to be certified in the CMP context. 529The I<priv> parameter must be 0 if and only if the given key is a public key. 530 531OSSL_CMP_CTX_get0_newPkey() gives the key to use for certificate enrollment 532dependent on fields of the CMP context structure: 533the newPkey (which may be a private or public key) if present, 534else the public key in the p10CSR if present, else the client's private key. 535If the I<priv> parameter is not 0 and the selected key does not have a 536private component then NULL is returned. 537 538OSSL_CMP_CTX_set1_issuer() sets the name of the intended issuer that 539will be set in the CertTemplate, i.e., the X509 name of the CA server. 540 541OSSL_CMP_CTX_set1_subjectName() sets the subject DN that will be used in 542the CertTemplate structure when requesting a new cert. For Key Update Requests 543(KUR), it defaults to the subject DN of the reference certificate, 544see OSSL_CMP_CTX_set1_oldCert(). This default is used for Initialization 545Requests (IR) and Certification Requests (CR) only if no SANs are set. 546The I<subjectName> is also used as fallback for the sender field 547of outgoing CMP messages if no reference certificate is available. 548 549OSSL_CMP_CTX_push1_subjectAltName() adds the given X509 name to the list of 550alternate names on the certificate template request. This cannot be used if 551any Subject Alternative Name extension is set via 552OSSL_CMP_CTX_set0_reqExtensions(). 553By default, unless B<OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT> has been set, 554the Subject Alternative Names are copied from the reference certificate, 555see OSSL_CMP_CTX_set1_oldCert(). 556If set and the subject DN is not set with OSSL_CMP_CTX_set1_subjectName() then 557the certificate template of an IR and CR will not be filled with the default 558subject DN from the reference certificate. 559If a subject DN is desired it needs to be set explicitly with 560OSSL_CMP_CTX_set1_subjectName(). 561 562OSSL_CMP_CTX_set0_reqExtensions() sets the X.509v3 extensions to be used in 563IR/CR/KUR. 564 565OSSL_CMP_CTX_reqExtensions_have_SAN() returns 1 if the context contains 566a Subject Alternative Name extension, else 0 or -1 on error. 567 568OSSL_CMP_CTX_push0_policy() adds the certificate policy info object 569to the X509_EXTENSIONS of the requested certificate template. 570 571OSSL_CMP_CTX_set1_oldCert() sets the old certificate to be updated in 572Key Update Requests (KUR) or to be revoked in Revocation Requests (RR). 573It must be given for RR, else it defaults to the CMP signer certificate. 574The I<reference certificate> determined in this way, if any, is also used for 575deriving default subject DN, public key, Subject Alternative Names, and the 576default issuer entry in the requested certificate template of IR/CR/KUR. 577The subject of the reference certificate is used as the sender field value 578in CMP message headers. 579Its issuer is used as default recipient in CMP message headers. 580 581OSSL_CMP_CTX_set1_p10CSR() sets the PKCS#10 CSR to use in P10CR messages. 582If such a CSR is provided, its subject, public key, and extension fields are 583also used as fallback values for the certificate template of IR/CR/KUR messages. 584 585OSSL_CMP_CTX_push0_genm_ITAV() adds I<itav> to the stack in the I<ctx> which 586will be the body of a General Message sent with this context. 587 588OSSL_CMP_certConf_cb() is the default certificate confirmation callback function. 589If the callback argument is not NULL it must point to a trust store. 590In this case the function checks that the newly enrolled certificate can be 591verified using this trust store and untrusted certificates from the I<ctx>, 592which have been augmented by the list of extraCerts received. 593During this verification, any certificate status checking is disabled. 594If the callback argument is NULL the function tries building an approximate 595chain as far as possible using the same untrusted certificates from the I<ctx>, 596and if this fails it takes the received extraCerts as fallback. 597The resulting cert chain can be retrieved using OSSL_CMP_CTX_get1_newChain(). 598 599OSSL_CMP_CTX_set_certConf_cb() sets the callback used for evaluating the newly 600enrolled certificate before the library sends, depending on its result, 601a positive or negative certConf message to the server. The callback has type 602 603 typedef int (*OSSL_CMP_certConf_cb_t) (OSSL_CMP_CTX *ctx, X509 *cert, 604 int fail_info, const char **txt); 605 606and should inspect the certificate it obtains via the I<cert> parameter and may 607overrule the pre-decision given in the I<fail_info> and I<*txt> parameters. 608If it accepts the certificate it must return 0, indicating success. Else it must 609return a bit field reflecting PKIFailureInfo with at least one failure bit and 610may set the I<*txt> output parameter to point to a string constant with more 611detail. The transfer callback may make use of a custom defined argument stored 612in the I<ctx> by means of OSSL_CMP_CTX_set_certConf_cb_arg(), which may be 613retrieved again through OSSL_CMP_CTX_get_certConf_cb_arg(). 614Typically, the callback will check at least that the certificate can be verified 615using a set of trusted certificates. 616It also could compare the subject DN and other fields of the newly 617enrolled certificate with the certificate template of the request. 618 619OSSL_CMP_CTX_set_certConf_cb_arg() sets an argument, respectively a pointer to a 620structure containing arguments, optionally to be used by the certConf callback. 621I<arg> is not consumed, and it must therefore explicitly be freed when not 622needed any more. I<arg> may be NULL to clear the entry. 623 624OSSL_CMP_CTX_get_certConf_cb_arg() gets the argument, respectively the pointer 625to a structure containing arguments, previously set by 626OSSL_CMP_CTX_set_certConf_cb_arg(), or NULL if unset. 627 628OSSL_CMP_CTX_get_status() returns for client contexts the PKIstatus from 629the last received CertRepMessage or Revocation Response or error message: 630=item B<OSSL_CMP_PKISTATUS_accepted> on successful receipt of a GENP message: 631 632=over 4 633 634=item B<OSSL_CMP_PKISTATUS_request> 635 636if an IR/CR/KUR/RR/GENM request message could not be produced, 637 638=item B<OSSL_CMP_PKISTATUS_trans> 639 640on a transmission error or transaction error for this type of request, and 641 642=item B<OSSL_CMP_PKISTATUS_unspecified> 643 644if no such request was attempted or OSSL_CMP_CTX_reinit() has been called. 645 646=back 647 648For server contexts it returns 649B<OSSL_CMP_PKISTATUS_trans> if a transaction is open, 650otherwise B<OSSL_CMP_PKISTATUS_unspecified>. 651 652OSSL_CMP_CTX_get0_statusString() returns the statusString from the last received 653CertRepMessage or Revocation Response or error message, or NULL if unset. 654 655OSSL_CMP_CTX_get_failInfoCode() returns the error code from the failInfo field 656of the last received CertRepMessage or Revocation Response or error message, 657or -1 if no such response was received or OSSL_CMP_CTX_reinit() has been called. 658This is a bit field and the flags for it are specified in the header file 659F<< <openssl/cmp.h> >>. 660The flags start with OSSL_CMP_CTX_FAILINFO, for example: 661OSSL_CMP_CTX_FAILINFO_badAlg. Returns -1 if the failInfoCode field is unset. 662 663OSSL_CMP_CTX_get0_newCert() returns the pointer to the newly obtained 664certificate in case it is available, else NULL. 665 666OSSL_CMP_CTX_get1_newChain() returns a pointer to a duplicate of the stack of 667X.509 certificates computed by OSSL_CMP_certConf_cb() (if this function has 668been called) on the last received certificate response message IP/CP/KUP. 669 670OSSL_CMP_CTX_get1_caPubs() returns a pointer to a duplicate of the list of 671X.509 certificates in the caPubs field of the last received certificate 672response message (of type IP, CP, or KUP), 673or an empty stack if no caPubs have been received in the current transaction. 674 675OSSL_CMP_CTX_get1_extraCertsIn() returns a pointer to a duplicate of the list 676of X.509 certificates contained in the extraCerts field of the last received 677response message (except for pollRep and PKIConf), or 678an empty stack if no extraCerts have been received in the current transaction. 679 680OSSL_CMP_CTX_set1_transactionID() sets the given transaction ID in the given 681OSSL_CMP_CTX structure. 682 683OSSL_CMP_CTX_set1_senderNonce() stores the last sent sender I<nonce> in 684the I<ctx>. This will be used to validate the recipNonce in incoming messages. 685 686=head1 NOTES 687 688CMP is defined in RFC 4210 (and CRMF in RFC 4211). 689 690=head1 RETURN VALUES 691 692OSSL_CMP_CTX_free() and OSSL_CMP_CTX_print_errors() do not return anything. 693 694OSSL_CMP_CTX_new(), 695OSSL_CMP_CTX_get_http_cb_arg(), 696OSSL_CMP_CTX_get_transfer_cb_arg(), 697OSSL_CMP_CTX_get0_trustedStore(), 698OSSL_CMP_CTX_get0_untrusted(), 699OSSL_CMP_CTX_get0_newPkey(), 700OSSL_CMP_CTX_get_certConf_cb_arg(), 701OSSL_CMP_CTX_get0_statusString(), 702OSSL_CMP_CTX_get0_newCert(), 703OSSL_CMP_CTX_get0_newChain(), 704OSSL_CMP_CTX_get1_caPubs(), and 705OSSL_CMP_CTX_get1_extraCertsIn() 706return the intended pointer value as described above or NULL on error. 707 708OSSL_CMP_CTX_get_option(), 709OSSL_CMP_CTX_reqExtensions_have_SAN(), 710OSSL_CMP_CTX_get_status(), and 711OSSL_CMP_CTX_get_failInfoCode() 712return the intended value as described above or -1 on error. 713 714OSSL_CMP_certConf_cb() returns I<fail_info> if it is not equal to 0, 715else 0 on successful validation, 716or else a bit field with the B<OSSL_CMP_PKIFAILUREINFO_incorrectData> bit set. 717 718All other functions, including OSSL_CMP_CTX_reinit() 719and OSSL_CMP_CTX_reset_geninfo_ITAVs(), 720return 1 on success, 0 on error. 721 722=head1 EXAMPLES 723 724The following code omits error handling. 725 726Set up a CMP client context for sending requests and verifying responses: 727 728 cmp_ctx = OSSL_CMP_CTX_new(); 729 OSSL_CMP_CTX_set1_server(cmp_ctx, name_or_address); 730 OSSL_CMP_CTX_set1_serverPort(cmp_ctx, port_string); 731 OSSL_CMP_CTX_set1_serverPath(cmp_ctx, path_or_alias); 732 OSSL_CMP_CTX_set0_trustedStore(cmp_ctx, ts); 733 734Set up symmetric credentials for MAC-based message protection such as PBM: 735 736 OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, ref, ref_len); 737 OSSL_CMP_CTX_set1_secretValue(cmp_ctx, sec, sec_len); 738 739Set up the details for certificate requests: 740 741 OSSL_CMP_CTX_set1_subjectName(cmp_ctx, name); 742 OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, initialKey); 743 744Perform an Initialization Request transaction: 745 746 initialCert = OSSL_CMP_exec_IR_ses(cmp_ctx); 747 748Reset the transaction state of the CMP context and the credentials: 749 750 OSSL_CMP_CTX_reinit(cmp_ctx); 751 OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, NULL, 0); 752 OSSL_CMP_CTX_set1_secretValue(cmp_ctx, NULL, 0); 753 754Perform a Certification Request transaction, making use of the new credentials: 755 756 OSSL_CMP_CTX_set1_cert(cmp_ctx, initialCert); 757 OSSL_CMP_CTX_set1_pkey(cmp_ctx, initialKey); 758 OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, curentKey); 759 currentCert = OSSL_CMP_exec_CR_ses(cmp_ctx); 760 761Perform a Key Update Request, signed using the cert (and key) to be updated: 762 763 OSSL_CMP_CTX_reinit(cmp_ctx); 764 OSSL_CMP_CTX_set1_cert(cmp_ctx, currentCert); 765 OSSL_CMP_CTX_set1_pkey(cmp_ctx, currentKey); 766 OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, updatedKey); 767 currentCert = OSSL_CMP_exec_KUR_ses(cmp_ctx); 768 currentKey = updatedKey; 769 770Perform a General Message transaction including, as an example, 771the id-it-signKeyPairTypes OID and prints info on the General Response contents: 772 773 OSSL_CMP_CTX_reinit(cmp_ctx); 774 775 ASN1_OBJECT *type = OBJ_txt2obj("1.3.6.1.5.5.7.4.2", 1); 776 OSSL_CMP_ITAV *itav = OSSL_CMP_ITAV_create(type, NULL); 777 OSSL_CMP_CTX_push0_genm_ITAV(cmp_ctx, itav); 778 779 STACK_OF(OSSL_CMP_ITAV) *itavs; 780 itavs = OSSL_CMP_exec_GENM_ses(cmp_ctx); 781 print_itavs(itavs); 782 sk_OSSL_CMP_ITAV_pop_free(itavs, OSSL_CMP_ITAV_free); 783 784=head1 SEE ALSO 785 786L<OSSL_CMP_exec_IR_ses(3)>, L<OSSL_CMP_exec_CR_ses(3)>, 787L<OSSL_CMP_exec_KUR_ses(3)>, L<OSSL_CMP_exec_GENM_ses(3)>, 788L<OSSL_CMP_exec_certreq(3)>, L<OSSL_CMP_MSG_http_perform(3)>, 789L<ERR_print_errors_cb(3)> 790 791=head1 HISTORY 792 793The OpenSSL CMP support was added in OpenSSL 3.0. 794 795OSSL_CMP_CTX_reset_geninfo_ITAVs() was added in OpenSSL 3.0.8. 796 797=head1 COPYRIGHT 798 799Copyright 2007-2023 The OpenSSL Project Authors. All Rights Reserved. 800 801Licensed under the Apache License 2.0 (the "License"). You may not use 802this file except in compliance with the License. You can obtain a copy 803in the file LICENSE in the source distribution or at 804L<https://www.openssl.org/source/license.html>. 805 806=cut 807