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 217The level of severity needed for actually outputting log messages 218due to errors, warnings, general info, debugging, etc. 219Default is OSSL_CMP_LOG_INFO. See also L<OSSL_CMP_log_open(3)>. 220 221=item B<OSSL_CMP_OPT_KEEP_ALIVE> 222 223If the given value is 0 then HTTP connections are not kept open 224after receiving a response, which is the default behavior for HTTP 1.0. 225If the value is 1 or 2 then persistent connections are requested. 226If the value is 2 then persistent connections are required, 227i.e., in case the server does not grant them an error occurs. 228The default value is 1: prefer to keep the connection open. 229 230=item B<OSSL_CMP_OPT_MSG_TIMEOUT> 231 232Number of seconds a CMP request-response message round trip 233is allowed to take before a timeout error is returned. 234A value <= 0 means no limitation (waiting indefinitely). 235Default is to use the B<OSSL_CMP_OPT_TOTAL_TIMEOUT> setting. 236 237=item B<OSSL_CMP_OPT_TOTAL_TIMEOUT> 238 239Maximum total number of seconds a transaction may take, 240including polling etc. 241A value <= 0 means no limitation (waiting indefinitely). 242Default is 0. 243 244=item B<OSSL_CMP_OPT_USE_TLS> 245 246Use this option to indicate to the HTTP implementation 247whether TLS is going to be used for the connection (resulting in HTTPS). 248The value 1 indicates that TLS is used for client-side HTTP connections, 249which needs to be implemented via a callback function set by 250OSSL_CMP_CTX_set_http_cb(). 251The value 0 indicates that TLS is not used. 252Default is -1 for backward compatibility: TLS is used by the client side 253if 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 257Number of days new certificates are asked to be valid for. 258 259=item B<OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT> 260 261Do not take default Subject Alternative Names 262from the reference certificate. 263 264=item B<OSSL_CMP_OPT_SUBJECTALTNAME_CRITICAL> 265 266Demand that the given Subject Alternative Names are flagged as critical. 267 268=item B<OSSL_CMP_OPT_POLICIES_CRITICAL> 269 270Demand that the given policies are flagged as critical. 271 272=item B<OSSL_CMP_OPT_POPO_METHOD> 273 274Select the proof of possession method to use. Possible values are: 275 276 OSSL_CRMF_POPO_NONE - ProofOfPossession field omitted, 277 which implies central key generation 278 OSSL_CRMF_POPO_RAVERIFIED - assert that the RA has already 279 verified the PoPo 280 OSSL_CRMF_POPO_SIGNATURE - sign a value with private key, 281 which is the default. 282 OSSL_CRMF_POPO_KEYENC - decrypt the encrypted certificate 283 ("indirect method") 284 285Note that a signature-based POPO can only be produced if a private key 286is provided as the newPkey or client's pkey component of the CMP context. 287 288=item B<OSSL_CMP_OPT_DIGEST_ALGNID> 289 290The NID of the digest algorithm to be used in RFC 4210's MSG_SIG_ALG 291for signature-based message protection and Proof-of-Possession (POPO). 292Default is SHA256. 293 294=item B<OSSL_CMP_OPT_OWF_ALGNID> 295The NID of the digest algorithm to be used as one-way function (OWF) 296for MAC-based message protection with password-based MAC (PBM). 297See RFC 4210 section 5.1.3.1 for details. 298Default is SHA256. 299 300=item B<OSSL_CMP_OPT_MAC_ALGNID> 301The NID of the MAC algorithm to be used for message protection with PBM. 302Default is HMAC-SHA1 as per RFC 4210. 303 304=item B<OSSL_CMP_OPT_REVOCATION_REASON> 305 306The reason code to be included in a Revocation Request (RR); 307values: 0..10 (RFC 5210, 5.3.1) or -1 for none, which is the default. 308 309=item B<OSSL_CMP_OPT_IMPLICIT_CONFIRM> 310 311Request server to enable implicit confirm mode, where the client 312does not need to send confirmation upon receiving the 313certificate. If the server does not enable implicit confirmation 314in the return message, then confirmation is sent anyway. 315 316=item B<OSSL_CMP_OPT_DISABLE_CONFIRM> 317 318Do not confirm enrolled certificates, to cope with broken servers 319not supporting implicit confirmation correctly. 320B<WARNING:> This setting leads to unspecified behavior and it is meant 321exclusively to allow interoperability with server implementations violating 322RFC 4210. 323 324=item B<OSSL_CMP_OPT_UNPROTECTED_SEND> 325 326Send request or response messages without CMP-level protection. 327 328=item B<OSSL_CMP_OPT_UNPROTECTED_ERRORS> 329 330Accept unprotected error responses which are either explicitly 331unprotected or where protection verification failed. Applies to regular 332error messages as well as certificate responses (IP/CP/KUP) and 333revocation responses (RP) with rejection. 334B<WARNING:> This setting leads to unspecified behavior and it is meant 335exclusively to allow interoperability with server implementations violating 336RFC 4210. 337 338=item B<OSSL_CMP_OPT_IGNORE_KEYUSAGE> 339 340Ignore key usage restrictions in the signer's certificate when 341validating signature-based protection in received CMP messages. 342Else, 'digitalSignature' must be allowed by CMP signer certificates. 343 344=item B<OSSL_CMP_OPT_PERMIT_TA_IN_EXTRACERTS_FOR_IR> 345 346Allow retrieving a trust anchor from extraCerts and using that 347to validate the certificate chain of an IP message. 348This is a quirk option added to support 3GPP TS 33.310. 349 350Note that using this option is dangerous as the certificate obtained 351this way has not been authenticated (at least not at CMP level). 352Taking it over as a trust anchor implements trust-on-first-use (TOFU). 353 354=item B<OSSL_CMP_OPT_NO_CACHE_EXTRACERTS> 355 356Do not cache certificates received in the extraCerts CMP message field. 357Otherwise they are stored to potentially help validate further messages. 358 359=back 360 361OSSL_CMP_CTX_get_option() reads the current value of the given option 362(e.g., OSSL_CMP_OPT_IMPLICIT_CONFIRM) from the given OSSL_CMP_CTX structure. 363 364OSSL_CMP_CTX_set_log_cb() sets in I<ctx> the callback function I<cb> 365for handling error queue entries and logging messages. 366When I<cb> is NULL errors are printed to STDERR (if available, else ignored) 367any log messages are ignored. 368Alternatively, L<OSSL_CMP_log_open(3)> may be used to direct logging to STDOUT. 369 370OSSL_CMP_CTX_set_log_verbosity() is a macro setting the 371OSSL_CMP_OPT_LOG_VERBOSITY context option to the given level. 372 373OSSL_CMP_CTX_print_errors() outputs any entries in the OpenSSL error queue. It 374is similar to L<ERR_print_errors_cb(3)> but uses the CMP log callback function 375if set in the I<ctx> for uniformity with CMP logging if given. Otherwise it uses 376L<ERR_print_errors(3)> to print to STDERR (unless OPENSSL_NO_STDIO is defined). 377 378OSSL_CMP_CTX_set1_serverPath() sets the HTTP path of the CMP server on the host, 379also known as "CMP alias". 380The default is C</>. 381 382OSSL_CMP_CTX_set1_server() sets the given server I<address> 383(which may be a hostname or IP address or NULL) in the given I<ctx>. 384If OSSL_CMP_CTX_get_transfer_cb_arg() sets a non-NULL argument, 385this server address information is used for diagnostic output only. 386 387OSSL_CMP_CTX_set_serverPort() sets the port of the CMP server to connect to. 388If not used or the I<port> argument is 0 389the default port applies, which is 80 for HTTP and 443 for HTTPS. 390If OSSL_CMP_CTX_get_transfer_cb_arg() sets a non-NULL argument, 391this server port information is used for diagnostic output only. 392 393OSSL_CMP_CTX_set1_proxy() sets the HTTP proxy to be used for connecting to 394the given CMP server unless overruled by any "no_proxy" settings (see below). 395If TLS is not used this defaults to the value of 396the environment variable C<http_proxy> if set, else C<HTTP_PROXY>. 397Otherwise defaults to the value of C<https_proxy> if set, else C<HTTPS_PROXY>. 398An empty proxy string specifies not to use a proxy. 399Otherwise the format is 400C<[http[s]://][userinfo@]host[:port][/path][?query][#fragment]>, 401where any given userinfo, path, query, and fragment is ignored. 402If the host string is an IPv6 address, it must be enclosed in C<[> and C<]>. 403The default port number is 80, or 443 in case C<https:> is given. 404 405OSSL_CMP_CTX_set1_no_proxy() sets the list of server hostnames not to use 406an HTTP proxy for. The names may be separated by commas and/or whitespace. 407Defaults to the environment variable C<no_proxy> if set, else C<NO_PROXY>. 408 409OSSL_CMP_CTX_set_http_cb() sets the optional BIO connect/disconnect callback 410function, which has the prototype 411 412 typedef BIO *(*HTTP_bio_cb_t) (BIO *bio, void *arg, int connect, int detail); 413 414The callback may modify the I<bio> provided by L<OSSL_CMP_MSG_http_perform(3)> 415as described for the I<bio_update_fn> parameter of L<OSSL_HTTP_open(3)>. 416The callback may make use of a custom defined argument I<arg>, 417as described for the I<arg> parameter of L<OSSL_HTTP_open(3)>. 418The argument is stored in the OSSL_CMP_CTX using OSSL_CMP_CTX_set_http_cb_arg(). 419See also the B<OSSL_CMP_OPT_USE_TLS> option described above. 420 421OSSL_CMP_CTX_set_http_cb_arg() sets the argument, respectively a pointer to 422a structure containing arguments such as an B<SSL_CTX> structure, 423optionally to be used by the http connect/disconnect callback function. 424I<arg> is not consumed, and it must therefore explicitly be freed when not 425needed any more. I<arg> may be NULL to clear the entry. 426If a non-NULL argument is set, it is an error to use OSSL_CMP_CTX_set1_proxy() 427or OSSL_CMP_CTX_set1_no_proxy() for setting non-NULL strings. 428 429OSSL_CMP_CTX_get_http_cb_arg() gets the argument, respectively the pointer to a 430structure containing arguments, previously set by 431OSSL_CMP_CTX_set_http_cb_arg() or NULL if unset. 432 433OSSL_CMP_CTX_set_transfer_cb() sets the message transfer callback function, 434which has the type 435 436 typedef OSSL_CMP_MSG *(*OSSL_CMP_transfer_cb_t) (OSSL_CMP_CTX *ctx, 437 const OSSL_CMP_MSG *req); 438 439Default is NULL, which implies the use of L<OSSL_CMP_MSG_http_perform(3)>. 440The callback should send the CMP request message it obtains via the I<req> 441parameter and on success return the response, else it must return NULL. 442The transfer callback may make use of a custom defined argument stored in 443the ctx by means of OSSL_CMP_CTX_set_transfer_cb_arg(), which may be retrieved 444again through OSSL_CMP_CTX_get_transfer_cb_arg(). 445 446OSSL_CMP_CTX_set_transfer_cb_arg() sets an argument, respectively a pointer to a 447structure containing arguments, optionally to be used by the transfer callback. 448I<arg> is not consumed, and it must therefore explicitly be freed when not 449needed any more. I<arg> may be NULL to clear the entry. 450 451OSSL_CMP_CTX_get_transfer_cb_arg() gets the argument, respectively the pointer 452to a structure containing arguments, previously set by 453OSSL_CMP_CTX_set_transfer_cb_arg() or NULL if unset. 454 455OSSL_CMP_CTX_set1_srvCert() sets the expected server cert in I<ctx> and trusts 456it directly (even if it is expired) when verifying signed response messages. 457This pins the accepted CMP server 458and results in ignoring whatever may be set using OSSL_CMP_CTX_set0_trusted(). 459Any previously set value is freed. 460The I<cert> argument may be NULL to clear the entry. 461If set, the subject of the certificate is also used 462as default value for the recipient of CMP requests 463and as default value for the expected sender of CMP responses. 464 465OSSL_CMP_CTX_set1_expected_sender() sets the Distinguished Name (DN) 466expected in the sender field of incoming CMP messages. 467Defaults to the subject of the pinned server certificate, if any. 468This can be used to make sure that only a particular entity is accepted as 469CMP message signer, and attackers are not able to use arbitrary certificates 470of a trusted PKI hierarchy to fraudulently pose as CMP server. 471Note that this gives slightly more freedom than OSSL_CMP_CTX_set1_srvCert(), 472which pins the server to the holder of a particular certificate, while the 473expected sender name will continue to match after updates of the server cert. 474 475OSSL_CMP_CTX_set0_trusted() is an alias of the original 476OSSL_CMP_CTX_set0_trustedStore(). 477It sets in the CMP context I<ctx> the certificate store of type X509_STORE 478containing trusted certificates, typically of root CAs. 479This is ignored when a certificate is pinned using OSSL_CMP_CTX_set1_srvCert(). 480The store may also hold CRLs and a certificate verification callback function 481used for signature-based peer authentication. 482Any store entry already set before is freed. 483When given a NULL parameter the entry is cleared. 484 485OSSL_CMP_CTX_get0_trusted() is an alias of the original 486OSSL_CMP_CTX_get0_trustedStore(). 487It extracts from the CMP context I<ctx> the pointer to the currently set 488certificate store containing trust anchors etc., or an empty store if unset. 489 490OSSL_CMP_CTX_set1_untrusted() sets up a list of non-trusted certificates 491of intermediate CAs that may be useful for path construction for the own CMP 492signer certificate, for the own TLS certificate (if any), when verifying peer 493CMP protection certificates, and when verifying newly enrolled certificates. 494The reference counts of those certificates handled successfully are increased. 495This list of untrusted certificates in I<ctx> will get augmented by extraCerts 496in received CMP messages unless B<OSSL_CMP_OPT_NO_CACHE_EXTRACERTS> is set. 497 498OSSL_CMP_CTX_get0_untrusted() returns a pointer to the 499list of untrusted certs in I<ctx>, which may be empty if unset. 500 501OSSL_CMP_CTX_set1_cert() sets the CMP I<signer certificate>, 502also called I<protection certificate>, 503related to the private key used for signature-based CMP message protection. 504Therefore the public key of this I<cert> must correspond to 505the private key set before or thereafter via OSSL_CMP_CTX_set1_pkey(). 506When using signature-based protection of CMP request messages 507this CMP signer certificate will be included first in the extraCerts field. 508It serves as fallback reference certificate, see OSSL_CMP_CTX_set1_oldCert(). 509The subject of this I<cert> will be used as the sender field of outgoing 510messages, while the subject of any cert set via OSSL_CMP_CTX_set1_oldCert(), 511the subject of any PKCS#10 CSR set via OSSL_CMP_CTX_set1_p10CSR(), 512and any value set via OSSL_CMP_CTX_set1_subjectName() are used as fallback. 513 514The I<cert> argument may be NULL to clear the entry. 515 516OSSL_CMP_CTX_build_cert_chain() builds a certificate chain for the CMP signer 517certificate previously set in the I<ctx>. It adds the optional I<candidates>, 518a list of intermediate CA certs that may already constitute the targeted chain, 519to the untrusted certs that may already exist in the I<ctx>. 520Then the function uses this augmented set of certs for chain construction. 521If I<own_trusted> is NULL it builds the chain as far down as possible and 522ignores any verification errors. Else the CMP signer certificate must be 523verifiable where the chain reaches a trust anchor contained in I<own_trusted>. 524On success the function stores the resulting chain in I<ctx> 525for inclusion in the extraCerts field of signature-protected messages. 526Calling this function is optional; by default a chain construction 527is performed on demand that is equivalent to calling this function 528with the I<candidates> and I<own_trusted> arguments being NULL. 529 530OSSL_CMP_CTX_set1_pkey() sets the client's private key corresponding to the 531CMP signer certificate set via OSSL_CMP_CTX_set1_cert(). 532This key is used create signature-based protection (protectionAlg = MSG_SIG_ALG) 533of outgoing messages 534unless a symmetric secret has been set via OSSL_CMP_CTX_set1_secretValue(). 535The I<pkey> argument may be NULL to clear the entry. 536 537OSSL_CMP_CTX_set1_secretValue() sets in I<ctx> the byte string I<sec> of length 538I<len> to use as pre-shared secret, or clears it if the I<sec> argument is NULL. 539If present, this secret is used to create MAC-based authentication and integrity 540protection (rather than applying signature-based protection) 541of outgoing messages and to verify authenticity and integrity of incoming 542messages that have MAC-based protection (protectionAlg = C<MSG_MAC_ALG>). 543 544OSSL_CMP_CTX_set1_referenceValue() sets the given referenceValue I<ref> with 545length I<len> in the given I<ctx> or clears it if the I<ref> argument is NULL. 546According to RFC 4210 section 5.1.1, if no value for the sender field in 547CMP message headers can be determined (i.e., no CMP signer certificate 548and no subject DN is set via OSSL_CMP_CTX_set1_subjectName() 549then the sender field will contain the NULL-DN 550and the senderKID field of the CMP message header must be set. 551When signature-based protection is used the senderKID will be set to 552the subjectKeyIdentifier of the CMP signer certificate as far as present. 553If not present or when MAC-based protection is used 554the I<ref> value is taken as the fallback value for the senderKID. 555 556OSSL_CMP_CTX_set1_recipient() sets the recipient name that will be used in the 557PKIHeader of CMP request messages, i.e. the X509 name of the (CA) server. 558 559The recipient field in the header of a CMP message is mandatory. 560If not given explicitly the recipient is determined in the following order: 561the subject of the CMP server certificate set using OSSL_CMP_CTX_set1_srvCert(), 562the value set using OSSL_CMP_CTX_set1_issuer(), 563the issuer of the certificate set using OSSL_CMP_CTX_set1_oldCert(), 564the issuer of the CMP signer certificate, 565as far as any of those is present, else the NULL-DN as last resort. 566 567OSSL_CMP_CTX_push0_geninfo_ITAV() adds I<itav> to the stack in the I<ctx> to be 568added to the generalInfo field of the CMP PKIMessage header of a request 569message sent with this context. 570 571OSSL_CMP_CTX_reset_geninfo_ITAVs() 572clears any ITAVs that were added by OSSL_CMP_CTX_push0_geninfo_ITAV(). 573 574OSSL_CMP_CTX_get0_geninfo_ITAVs() returns the list of ITAVs set in I<ctx> 575for inclusion in the generalInfo field of the CMP PKIMessage header of requests 576or NULL if not set. 577 578OSSL_CMP_CTX_set1_extraCertsOut() sets the stack of extraCerts that will be 579sent to remote. 580 581OSSL_CMP_CTX_set0_newPkey() can be used to explicitly set the given EVP_PKEY 582structure as the private or public key to be certified in the CMP context. 583The I<priv> parameter must be 0 if and only if the given key is a public key. 584 585OSSL_CMP_CTX_get0_newPkey() gives the key to use for certificate enrollment 586dependent on fields of the CMP context structure: 587the newPkey (which may be a private or public key) if present, 588else the public key in the p10CSR if present, else the client's private key. 589If the I<priv> parameter is not 0 and the selected key does not have a 590private component then NULL is returned. 591 592OSSL_CMP_CTX_set1_issuer() sets the name of the intended issuer that 593will be set in the CertTemplate, i.e., the X509 name of the CA server. 594 595OSSL_CMP_CTX_set1_serialNumber() sets the serial number optionally used to 596select the certificate to be revoked in Revocation Requests (RR). 597 598OSSL_CMP_CTX_set1_subjectName() sets the subject DN that will be used in 599the CertTemplate structure when requesting a new cert. For Key Update Requests 600(KUR), it defaults to the subject DN of the reference certificate, 601see OSSL_CMP_CTX_set1_oldCert(). This default is used for Initialization 602Requests (IR) and Certification Requests (CR) only if no SANs are set. 603The I<subjectName> is also used as fallback for the sender field 604of outgoing CMP messages if no reference certificate is available. 605 606OSSL_CMP_CTX_push1_subjectAltName() adds the given X509 name to the list of 607alternate names on the certificate template request. This cannot be used if 608any Subject Alternative Name extension is set via 609OSSL_CMP_CTX_set0_reqExtensions(). 610By default, unless B<OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT> has been set, 611the Subject Alternative Names are copied from the reference certificate, 612see OSSL_CMP_CTX_set1_oldCert(). 613If set and the subject DN is not set with OSSL_CMP_CTX_set1_subjectName() then 614the certificate template of an IR and CR will not be filled with the default 615subject DN from the reference certificate. 616If a subject DN is desired it needs to be set explicitly with 617OSSL_CMP_CTX_set1_subjectName(). 618 619OSSL_CMP_CTX_set0_reqExtensions() sets the X.509v3 extensions to be used in 620IR/CR/KUR. 621 622OSSL_CMP_CTX_reqExtensions_have_SAN() returns 1 if the context contains 623a Subject Alternative Name extension, else 0 or -1 on error. 624 625OSSL_CMP_CTX_push0_policy() adds the certificate policy info object 626to the X509_EXTENSIONS of the requested certificate template. 627 628OSSL_CMP_CTX_set1_oldCert() sets the old certificate to be updated in 629Key Update Requests (KUR) or to be revoked in Revocation Requests (RR). 630For RR, this is ignored if an issuer name and a serial number are provided using 631OSSL_CMP_CTX_set1_issuer() and OSSL_CMP_CTX_set1_serialNumber(), respectively. 632For IR/CR/KUR this sets the I<reference certificate>, 633which otherwise defaults to the CMP signer certificate. 634The I<reference certificate> determined this way, if any, is used for providing 635default public key, subject DN, Subject Alternative Names, and issuer DN entries 636in the requested certificate template of IR/CR/KUR messages. 637 638The subject of the reference certificate is used as the sender field value 639in CMP message headers. 640Its issuer is used as default recipient in CMP message headers. 641 642OSSL_CMP_CTX_set1_p10CSR() sets the PKCS#10 CSR to use in P10CR messages. 643If such a CSR is provided, its subject and public key fields are also 644used as fallback values for the certificate template of IR/CR/KUR/RR messages, 645and any extensions included are added to the template of IR/CR/KUR messages. 646 647OSSL_CMP_CTX_push0_genm_ITAV() adds I<itav> to the stack in the I<ctx> which 648will be the body of a General Message sent with this context. 649 650OSSL_CMP_certConf_cb() is the default certificate confirmation callback function. 651If the callback argument is not NULL it must point to a trust store. 652In this case the function checks that the newly enrolled certificate can be 653verified using this trust store and untrusted certificates from the I<ctx>, 654which have been augmented by the list of extraCerts received. 655During this verification, any certificate status checking is disabled. 656If the callback argument is NULL the function tries building an approximate 657chain as far as possible using the same untrusted certificates from the I<ctx>, 658and if this fails it takes the received extraCerts as fallback. 659The resulting cert chain can be retrieved using OSSL_CMP_CTX_get1_newChain(). 660This chain excludes the leaf certificate, i.e., the newly enrolled certificate. 661Also the trust anchor (the root certificate) is not included. 662 663OSSL_CMP_CTX_set_certConf_cb() sets the callback used for evaluating the newly 664enrolled certificate before the library sends, depending on its result, 665a positive or negative certConf message to the server. The callback has type 666 667 typedef int (*OSSL_CMP_certConf_cb_t) (OSSL_CMP_CTX *ctx, X509 *cert, 668 int fail_info, const char **txt); 669 670and should inspect the certificate it obtains via the I<cert> parameter and may 671overrule the pre-decision given in the I<fail_info> and I<*txt> parameters. 672If it accepts the certificate it must return 0, indicating success. Else it must 673return a bit field reflecting PKIFailureInfo with at least one failure bit and 674may set the I<*txt> output parameter to point to a string constant with more 675detail. The transfer callback may make use of a custom defined argument stored 676in the I<ctx> by means of OSSL_CMP_CTX_set_certConf_cb_arg(), which may be 677retrieved again through OSSL_CMP_CTX_get_certConf_cb_arg(). 678Typically, the callback will check at least that the certificate can be verified 679using a set of trusted certificates. 680It also could compare the subject DN and other fields of the newly 681enrolled certificate with the certificate template of the request. 682 683OSSL_CMP_CTX_set_certConf_cb_arg() sets an argument, respectively a pointer to a 684structure containing arguments, optionally to be used by the certConf callback. 685I<arg> is not consumed, and it must therefore explicitly be freed when not 686needed any more. I<arg> may be NULL to clear the entry. 687 688OSSL_CMP_CTX_get_certConf_cb_arg() gets the argument, respectively the pointer 689to a structure containing arguments, previously set by 690OSSL_CMP_CTX_set_certConf_cb_arg(), or NULL if unset. 691 692OSSL_CMP_CTX_get_status() returns for client contexts the PKIstatus from 693the last received CertRepMessage or Revocation Response or error message: 694=item B<OSSL_CMP_PKISTATUS_accepted> on successful receipt of a GENP message: 695 696=over 4 697 698=item B<OSSL_CMP_PKISTATUS_request> 699 700if an IR/CR/KUR/RR/GENM request message could not be produced, 701 702=item B<OSSL_CMP_PKISTATUS_trans> 703 704on a transmission error or transaction error for this type of request, and 705 706=item B<OSSL_CMP_PKISTATUS_unspecified> 707 708if no such request was attempted or OSSL_CMP_CTX_reinit() has been called. 709 710=back 711 712For server contexts it returns 713B<OSSL_CMP_PKISTATUS_trans> if a transaction is open, 714otherwise B<OSSL_CMP_PKISTATUS_unspecified>. 715 716OSSL_CMP_CTX_get0_statusString() returns the statusString from the last received 717CertRepMessage or Revocation Response or error message, or NULL if unset. 718 719OSSL_CMP_CTX_get_failInfoCode() returns the error code from the failInfo field 720of the last received CertRepMessage or Revocation Response or error message, 721or -1 if no such response was received or OSSL_CMP_CTX_reinit() has been called. 722This is a bit field and the flags for it are specified in the header file 723F<< <openssl/cmp.h> >>. 724The flags start with OSSL_CMP_CTX_FAILINFO, for example: 725OSSL_CMP_CTX_FAILINFO_badAlg. Returns -1 if the failInfoCode field is unset. 726 727OSSL_CMP_CTX_get0_validatedSrvCert() returns 728the successfully validated certificate, if any, that the CMP server used 729in the current transaction for signature-based response message protection, 730or NULL if the server used MAC-based protection. 731The value is relevant only at the end of a successful transaction. 732It may be used to check the authorization of the server based on its cert. 733 734OSSL_CMP_CTX_get0_newCert() returns the pointer to the newly obtained 735certificate in case it is available, else NULL. 736 737OSSL_CMP_CTX_get1_newChain() returns a pointer to a duplicate of the stack of 738X.509 certificates computed by OSSL_CMP_certConf_cb() (if this function has 739been called) on the last received certificate response message IP/CP/KUP. 740 741OSSL_CMP_CTX_get1_caPubs() returns a pointer to a duplicate of the list of 742X.509 certificates in the caPubs field of the last received certificate 743response message (of type IP, CP, or KUP), 744or an empty stack if no caPubs have been received in the current transaction. 745 746OSSL_CMP_CTX_get1_extraCertsIn() returns a pointer to a duplicate of the list 747of X.509 certificates contained in the extraCerts field of the last received 748response message (except for pollRep and PKIConf), or 749an empty stack if no extraCerts have been received in the current transaction. 750 751OSSL_CMP_CTX_set1_transactionID() sets the given transaction ID in the given 752OSSL_CMP_CTX structure. 753 754OSSL_CMP_CTX_set1_senderNonce() stores the last sent sender I<nonce> in 755the I<ctx>. This will be used to validate the recipNonce in incoming messages. 756 757=head1 NOTES 758 759CMP is defined in RFC 4210 (and CRMF in RFC 4211). 760 761=head1 RETURN VALUES 762 763OSSL_CMP_CTX_free() and OSSL_CMP_CTX_print_errors() do not return anything. 764 765OSSL_CMP_CTX_new(), 766OSSL_CMP_CTX_get0_libctx(), OSSL_CMP_CTX_get0_propq(), 767OSSL_CMP_CTX_get_http_cb_arg(), 768OSSL_CMP_CTX_get_transfer_cb_arg(), 769OSSL_CMP_CTX_get0_trusted(), 770OSSL_CMP_CTX_get0_untrusted(), 771OSSL_CMP_CTX_get0_geninfo_ITAVs(), 772OSSL_CMP_CTX_get0_newPkey(), 773OSSL_CMP_CTX_get_certConf_cb_arg(), 774OSSL_CMP_CTX_get0_statusString(), 775OSSL_CMP_CTX_get0_validatedSrvCert(), 776OSSL_CMP_CTX_get0_newCert(), 777OSSL_CMP_CTX_get0_newChain(), 778OSSL_CMP_CTX_get1_caPubs(), and 779OSSL_CMP_CTX_get1_extraCertsIn() 780return the intended pointer value as described above or NULL on error. 781 782OSSL_CMP_CTX_get_option(), 783OSSL_CMP_CTX_reqExtensions_have_SAN(), 784OSSL_CMP_CTX_get_status(), and 785OSSL_CMP_CTX_get_failInfoCode() 786return the intended value as described above or -1 on error. 787 788OSSL_CMP_certConf_cb() returns I<fail_info> if it is not equal to 0, 789else 0 on successful validation, 790or else a bit field with the B<OSSL_CMP_PKIFAILUREINFO_incorrectData> bit set. 791 792All other functions, including OSSL_CMP_CTX_reinit() 793and OSSL_CMP_CTX_reset_geninfo_ITAVs(), 794return 1 on success, 0 on error. 795 796=head1 EXAMPLES 797 798The following code omits error handling. 799 800Set up a CMP client context for sending requests and verifying responses: 801 802 cmp_ctx = OSSL_CMP_CTX_new(); 803 OSSL_CMP_CTX_set1_server(cmp_ctx, name_or_address); 804 OSSL_CMP_CTX_set1_serverPort(cmp_ctx, port_string); 805 OSSL_CMP_CTX_set1_serverPath(cmp_ctx, path_or_alias); 806 OSSL_CMP_CTX_set0_trusted(cmp_ctx, ts); 807 808Set up symmetric credentials for MAC-based message protection such as PBM: 809 810 OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, ref, ref_len); 811 OSSL_CMP_CTX_set1_secretValue(cmp_ctx, sec, sec_len); 812 813Set up the details for certificate requests: 814 815 OSSL_CMP_CTX_set1_subjectName(cmp_ctx, name); 816 OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, initialKey); 817 818Perform an Initialization Request transaction: 819 820 initialCert = OSSL_CMP_exec_IR_ses(cmp_ctx); 821 822Reset the transaction state of the CMP context and the credentials: 823 824 OSSL_CMP_CTX_reinit(cmp_ctx); 825 OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, NULL, 0); 826 OSSL_CMP_CTX_set1_secretValue(cmp_ctx, NULL, 0); 827 828Perform a Certification Request transaction, making use of the new credentials: 829 830 OSSL_CMP_CTX_set1_cert(cmp_ctx, initialCert); 831 OSSL_CMP_CTX_set1_pkey(cmp_ctx, initialKey); 832 OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, curentKey); 833 currentCert = OSSL_CMP_exec_CR_ses(cmp_ctx); 834 835Perform a Key Update Request, signed using the cert (and key) to be updated: 836 837 OSSL_CMP_CTX_reinit(cmp_ctx); 838 OSSL_CMP_CTX_set1_cert(cmp_ctx, currentCert); 839 OSSL_CMP_CTX_set1_pkey(cmp_ctx, currentKey); 840 OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, updatedKey); 841 currentCert = OSSL_CMP_exec_KUR_ses(cmp_ctx); 842 currentKey = updatedKey; 843 844Perform a General Message transaction including, as an example, 845the id-it-signKeyPairTypes OID and prints info on the General Response contents: 846 847 OSSL_CMP_CTX_reinit(cmp_ctx); 848 849 ASN1_OBJECT *type = OBJ_txt2obj("1.3.6.1.5.5.7.4.2", 1); 850 OSSL_CMP_ITAV *itav = OSSL_CMP_ITAV_create(type, NULL); 851 OSSL_CMP_CTX_push0_genm_ITAV(cmp_ctx, itav); 852 853 STACK_OF(OSSL_CMP_ITAV) *itavs; 854 itavs = OSSL_CMP_exec_GENM_ses(cmp_ctx); 855 print_itavs(itavs); 856 sk_OSSL_CMP_ITAV_pop_free(itavs, OSSL_CMP_ITAV_free); 857 858=head1 SEE ALSO 859 860L<OSSL_CMP_exec_IR_ses(3)>, L<OSSL_CMP_exec_CR_ses(3)>, 861L<OSSL_CMP_exec_KUR_ses(3)>, L<OSSL_CMP_exec_GENM_ses(3)>, 862L<OSSL_CMP_exec_certreq(3)>, L<OSSL_CMP_MSG_http_perform(3)>, 863L<ERR_print_errors_cb(3)>, L<OSSL_HTTP_open(3)> 864 865=head1 HISTORY 866 867The OpenSSL CMP support was added in OpenSSL 3.0. 868 869OSSL_CMP_CTX_get0_trustedStore() was renamed to OSSL_CMP_CTX_get0_trusted() and 870OSSL_CMP_CTX_set0_trustedStore() was renamed to OSSL_CMP_CTX_set0_trusted(), 871using macros, while keeping the old names for backward compatibility, 872in OpenSSL 3.2. 873 874OSSL_CMP_CTX_reset_geninfo_ITAVs() was added in OpenSSL 3.0.8. 875 876OSSL_CMP_CTX_set1_serialNumber(), 877OSSL_CMP_CTX_get0_libctx(), OSSL_CMP_CTX_get0_propq(), and 878OSSL_CMP_CTX_get0_validatedSrvCert() were added in OpenSSL 3.2. 879 880OSSL_CMP_CTX_get0_geninfo_ITAVs() was added in OpenSSL 3.3. 881 882Support for central key generation, requested via B<OSSL_CRMF_POPO_NONE>, 883was added in OpenSSL 3.5. 884 885=head1 COPYRIGHT 886 887Copyright 2007-2025 The OpenSSL Project Authors. All Rights Reserved. 888 889Licensed under the Apache License 2.0 (the "License"). You may not use 890this file except in compliance with the License. You can obtain a copy 891in the file LICENSE in the source distribution or at 892L<https://www.openssl.org/source/license.html>. 893 894=cut 895