- NAME
- SYNOPSIS
- DESCRIPTION
- NOTES
- RETURN VALUES
- EXAMPLES
- SEE ALSO
- HISTORY
- COPYRIGHT

# NAME

OSSL_CMP_CTX_new, OSSL_CMP_CTX_free, OSSL_CMP_CTX_reinit, OSSL_CMP_CTX_set_option, OSSL_CMP_CTX_get_option, OSSL_CMP_CTX_set_log_cb, OSSL_CMP_CTX_set_log_verbosity, OSSL_CMP_CTX_print_errors, OSSL_CMP_CTX_set1_serverPath, OSSL_CMP_CTX_set1_serverName, OSSL_CMP_CTX_set_serverPort, OSSL_CMP_CTX_set1_proxyName, OSSL_CMP_CTX_set_proxyPort, OSSL_CMP_DEFAULT_PORT, OSSL_CMP_CTX_set_http_cb, OSSL_CMP_CTX_set_http_cb_arg, OSSL_CMP_CTX_get_http_cb_arg, OSSL_cmp_transfer_cb_t, OSSL_CMP_CTX_set_transfer_cb, OSSL_CMP_CTX_set_transfer_cb_arg, OSSL_CMP_CTX_get_transfer_cb_arg, OSSL_CMP_CTX_set1_srvCert, OSSL_CMP_CTX_set1_expected_sender, OSSL_CMP_CTX_set0_trustedStore, OSSL_CMP_CTX_get0_trustedStore, OSSL_CMP_CTX_set1_untrusted_certs, OSSL_CMP_CTX_get0_untrusted_certs, OSSL_CMP_CTX_set1_clCert, OSSL_CMP_CTX_set1_pkey, OSSL_CMP_CTX_set1_referenceValue, OSSL_CMP_CTX_set1_secretValue, OSSL_CMP_CTX_set1_recipient, OSSL_CMP_CTX_push0_geninfo_ITAV, OSSL_CMP_CTX_set1_extraCertsOut, OSSL_CMP_CTX_set0_newPkey, OSSL_CMP_CTX_get0_newPkey, OSSL_CMP_CTX_set1_issuer, OSSL_CMP_CTX_set1_subjectName, OSSL_CMP_CTX_push1_subjectAltName, OSSL_CMP_CTX_set0_reqExtensions, OSSL_CMP_CTX_reqExtensions_have_SAN, OSSL_CMP_CTX_push0_policy, OSSL_CMP_CTX_set1_oldCert, OSSL_CMP_CTX_set1_p10CSR, OSSL_CMP_CTX_push0_genm_ITAV, OSSL_cmp_certConf_cb_t, OSSL_CMP_CTX_set_certConf_cb, OSSL_CMP_CTX_set_certConf_cb_arg, OSSL_CMP_CTX_get_certConf_cb_arg, OSSL_CMP_CTX_get_status, OSSL_CMP_CTX_get0_statusString, OSSL_CMP_CTX_get_failInfoCode, OSSL_CMP_CTX_get0_newCert, OSSL_CMP_CTX_get1_caPubs, OSSL_CMP_CTX_get1_extraCertsIn, OSSL_CMP_CTX_set1_transactionID, OSSL_CMP_CTX_set1_senderNonce - functions for managing the CMP client context data structure

# SYNOPSIS

     #include <openssl/cmp.h>

     OSSL_CMP_CTX *OSSL_CMP_CTX_new(void);
     void OSSL_CMP_CTX_free(OSSL_CMP_CTX *ctx);
     int OSSL_CMP_CTX_reinit(OSSL_CMP_CTX *ctx);
     int OSSL_CMP_CTX_set_option(OSSL_CMP_CTX *ctx, int opt, int val);
     int OSSL_CMP_CTX_get_option(const OSSL_CMP_CTX *ctx, int opt);

     /* logging and error reporting: */
     int OSSL_CMP_CTX_set_log_cb(OSSL_CMP_CTX *ctx, OSSL_cmp_log_cb_t cb);
     #define OSSL_CMP_CTX_set_log_verbosity(ctx, level)
     void OSSL_CMP_CTX_print_errors(OSSL_CMP_CTX *ctx);

     /* message transfer: */
     int OSSL_CMP_CTX_set1_serverPath(OSSL_CMP_CTX *ctx, const char *path);
     int OSSL_CMP_CTX_set1_serverName(OSSL_CMP_CTX *ctx, const char *name);
     int OSSL_CMP_CTX_set_serverPort(OSSL_CMP_CTX *ctx, int port);
     int OSSL_CMP_CTX_set1_proxyName(OSSL_CMP_CTX *ctx, const char *name);
     int OSSL_CMP_CTX_set_proxyPort(OSSL_CMP_CTX *ctx, int port);
     #define OSSL_CMP_DEFAULT_PORT 80
     int OSSL_CMP_CTX_set_http_cb(OSSL_CMP_CTX *ctx, HTTP_bio_cb_t cb);
     int OSSL_CMP_CTX_set_http_cb_arg(OSSL_CMP_CTX *ctx, void *arg);
     void *OSSL_CMP_CTX_get_http_cb_arg(const OSSL_CMP_CTX *ctx);
     typedef OSSL_CMP_MSG *(*OSSL_cmp_transfer_cb_t)(OSSL_CMP_CTX *ctx,
                                                     const OSSL_CMP_MSG *req);
     int OSSL_CMP_CTX_set_transfer_cb(OSSL_CMP_CTX *ctx,
                                      OSSL_cmp_transfer_cb_t cb);
     int OSSL_CMP_CTX_set_transfer_cb_arg(OSSL_CMP_CTX *ctx, void *arg);
     void *OSSL_CMP_CTX_get_transfer_cb_arg(const OSSL_CMP_CTX *ctx);

     /* server authentication: */
     int OSSL_CMP_CTX_set1_srvCert(OSSL_CMP_CTX *ctx, X509 *cert);
     int OSSL_CMP_CTX_set1_expected_sender(OSSL_CMP_CTX *ctx,
                                          const X509_NAME *name);
     int OSSL_CMP_CTX_set0_trustedStore(OSSL_CMP_CTX *ctx, X509_STORE *store);
     X509_STORE *OSSL_CMP_CTX_get0_trustedStore(const OSSL_CMP_CTX *ctx);
     int OSSL_CMP_CTX_set1_untrusted_certs(OSSL_CMP_CTX *ctx,
                                           STACK_OF(X509) *certs);
     STACK_OF(X509) *OSSL_CMP_CTX_get0_untrusted_certs(const OSSL_CMP_CTX *ctx);

     /* client authentication: */
     int OSSL_CMP_CTX_set1_clCert(OSSL_CMP_CTX *ctx, X509 *cert);
     int OSSL_CMP_CTX_set1_pkey(OSSL_CMP_CTX *ctx, EVP_PKEY *pkey);
     int OSSL_CMP_CTX_set1_referenceValue(OSSL_CMP_CTX *ctx,
                                          const unsigned char *ref, int len);
     int OSSL_CMP_CTX_set1_secretValue(OSSL_CMP_CTX *ctx, const unsigned char *sec,
                                       const int len);

     /* CMP message header and extra certificates: */
     int OSSL_CMP_CTX_set1_recipient(OSSL_CMP_CTX *ctx, const X509_NAME *name);
     int OSSL_CMP_CTX_push0_geninfo_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav);
     int OSSL_CMP_CTX_set1_extraCertsOut(OSSL_CMP_CTX *ctx,
                                         STACK_OF(X509) *extraCertsOut);

     /* certificate template: */
     int OSSL_CMP_CTX_set0_newPkey(OSSL_CMP_CTX *ctx, int priv, EVP_PKEY *pkey);
     EVP_PKEY *OSSL_CMP_CTX_get0_newPkey(const OSSL_CMP_CTX *ctx, int priv);
     int OSSL_CMP_CTX_set1_issuer(OSSL_CMP_CTX *ctx, const X509_NAME *name);
     int OSSL_CMP_CTX_set1_subjectName(OSSL_CMP_CTX *ctx, const X509_NAME *name);
     int OSSL_CMP_CTX_push1_subjectAltName(OSSL_CMP_CTX *ctx,
                                           const GENERAL_NAME *name);
     int OSSL_CMP_CTX_set0_reqExtensions(OSSL_CMP_CTX *ctx, X509_EXTENSIONS *exts);
     int OSSL_CMP_CTX_reqExtensions_have_SAN(OSSL_CMP_CTX *ctx);
     int OSSL_CMP_CTX_push0_policy(OSSL_CMP_CTX *ctx, POLICYINFO *pinfo);
     int OSSL_CMP_CTX_set1_oldCert(OSSL_CMP_CTX *ctx, X509 *cert);
     int OSSL_CMP_CTX_set1_p10CSR(OSSL_CMP_CTX *ctx, const X509_REQ *csr);

     /* misc body contents: */
     int OSSL_CMP_CTX_push0_genm_ITAV(OSSL_CMP_CTX *ctx, OSSL_CMP_ITAV *itav);

     /* certificate confirmation: */
     typedef int (*OSSL_cmp_certConf_cb_t)(OSSL_CMP_CTX *ctx, X509 *cert,
                                           int fail_info, const char **txt);
     int OSSL_CMP_CTX_set_certConf_cb(OSSL_CMP_CTX *ctx, OSSL_cmp_certConf_cb_t cb);
     int OSSL_CMP_CTX_set_certConf_cb_arg(OSSL_CMP_CTX *ctx, void *arg);
     void *OSSL_CMP_CTX_get_certConf_cb_arg(const OSSL_CMP_CTX *ctx);

     /* result fetching: */
     int OSSL_CMP_CTX_get_status(const OSSL_CMP_CTX *ctx);
     OSSL_CMP_PKIFREETEXT *OSSL_CMP_CTX_get0_statusString(const OSSL_CMP_CTX *ctx);
     int OSSL_CMP_CTX_get_failInfoCode(const OSSL_CMP_CTX *ctx);

     X509 *OSSL_CMP_CTX_get0_newCert(const OSSL_CMP_CTX *ctx);
     STACK_OF(X509) *OSSL_CMP_CTX_get1_caPubs(const OSSL_CMP_CTX *ctx);
     STACK_OF(X509) *OSSL_CMP_CTX_get1_extraCertsIn(const OSSL_CMP_CTX *ctx);

     /* for test purposes only: */
     int OSSL_CMP_CTX_set1_transactionID(OSSL_CMP_CTX *ctx,
                                         const ASN1_OCTET_STRING *id);
     int OSSL_CMP_CTX_set1_senderNonce(OSSL_CMP_CTX *ctx,
                                       const ASN1_OCTET_STRING *nonce);

# DESCRIPTION

This is the context API for using CMP (Certificate Management Protocol) with OpenSSL.

`OSSL_CMP_CTX_new()` allocates and initializes an OSSL_CMP_CTX structure to default values, e.g., proof-of-possession method is set to POPOSigningKey.

`OSSL_CMP_CTX_free()` deallocates an OSSL_CMP_CTX structure.

`OSSL_CMP_CTX_reinit()` prepares the given ctx for a further transaction by clearing the internal CMP transaction (aka session) status, PKIStatusInfo, and any previous results (newCert, caPubs, and extraCertsIn) from the last executed transaction. All other field values (i.e., CMP options) are retained for potential re-use.

`OSSL_CMP_CTX_set_option()` sets the given value for the given option (e.g., OSSL_CMP_OPT_IMPLICITCONFIRM) in the given OSSL_CMP_CTX structure.

The following options can be set:

OSSL_CMP_OPT_LOG_VERBOSITY

              The level of severity needed for actually outputting log messages
              due to errors, warnings, general info, debugging, etc.
              Default is OSSL_CMP_LOG_INFO. See also L<OSSL_CMP_log_open(3)>.

OSSL_CMP_OPT_MSGTIMEOUT

              Number of seconds (or 0 for infinite) a CMP message round trip is
              allowed to take before a timeout error is returned. Default is 120.

OSSL_CMP_OPT_TOTALTIMEOUT

              Maximum total number of seconds an enrollment (including polling)
              may take. Default is 0 (infinite).

OSSL_CMP_OPT_VALIDITYDAYS

              Number of days new certificates are asked to be valid for.

OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT

              Do not take default Subject Alternative Names
              from the reference certificate.

OSSL_CMP_OPT_SUBJECTALTNAME_CRITICAL

              Demand that the given Subject Alternative Names are flagged as critical.

OSSL_CMP_OPT_POLICIES_CRITICAL

              Demand that the given policies are flagged as critical.

OSSL_CMP_OPT_POPOMETHOD

              Select the proof of possession method to use. Possible values are:

                  OSSL_CRMF_POPO_NONE       - ProofOfPossession field omitted
                  OSSL_CRMF_POPO_RAVERIFIED - assert that the RA has already
                                              verified the PoPo
                  OSSL_CRMF_POPO_SIGNATURE  - sign a value with private key,
                                              which is the default.
                  OSSL_CRMF_POPO_KEYENC     - decrypt the encrypted certificate
                                              ("indirect method")

              Note that a signature-based POPO can only be produced if a private key
              is provided as the newPkey or client pkey component of the CMP context.

OSSL_CMP_OPT_DIGEST_ALGNID

              The digest algorithm NID to be used in RFC 4210's MSG_SIG_ALG,
              if applicable used for message protection and Proof-of-Possession.
              Default is SHA256.

          OSSL_CMP_OPT_OWF_ALGNID
              The digest algorithm NID to be used as one-way function (OWF)
              in RFC 4210's MSG_MAC_ALG, if applicable used for message protection.
              Default is SHA256.

          OSSL_CMP_OPT_MAC_ALGNID
              The MAC algorithm NID to be used in RFC 4210's MSG_MAC_ALG,
              if applicable used for message protection.
              Default is HMAC-SHA1 as per RFC 4210.

OSSL_CMP_OPT_REVOCATION_REASON

              The reason code to be included in a Revocation Request (RR);
              values: 0..10 (RFC 5210, 5.3.1) or -1 for none, which is the default.

OSSL_CMP_OPT_IMPLICITCONFIRM

              Request server to enable implicit confirm mode, where the client
              does not need to send confirmation upon receiving the
              certificate. If the server does not enable implicit confirmation
              in the return message, then confirmation is sent anyway.

OSSL_CMP_OPT_DISABLECONFIRM

              Do not confirm enrolled certificates, to cope with broken servers
              not supporting implicit confirmation correctly.
      B<WARNING:> This setting leads to unspecified behavior and it is meant
      exclusively to allow interoperability with server implementations violating
      RFC 4210.

OSSL_CMP_OPT_UNPROTECTED_SEND

              Send messages without CMP-level protection.

OSSL_CMP_OPT_UNPROTECTED_ERRORS

              Accept unprotected error responses which are either explicitly
              unprotected or where protection verification failed. Applies to regular
              error messages as well as certificate responses (IP/CP/KUP) and
              revocation responses (RP) with rejection.
      B<WARNING:> This setting leads to unspecified behavior and it is meant
      exclusively to allow interoperability with server implementations violating
      RFC 4210.

OSSL_CMP_OPT_IGNORE_KEYUSAGE

              Ignore key usage restrictions in signer certificate when
              validating signature-based protection in received CMP messages.
              Else, 'digitalSignature' must be allowed by CMP signer certificates.

OSSL_CMP_OPT_PERMIT_TA_IN_EXTRACERTS_FOR_IR

              Allow retrieving a trust anchor from extraCerts and using that
              to validate the certificate chain of an IP message.

`OSSL_CMP_CTX_get_option()` reads the current value of the given option (e.g., OSSL_CMP_OPT_IMPLICITCONFIRM) from the given OSSL_CMP_CTX structure.

`OSSL_CMP_CTX_set_log_cb()` sets in ctx the callback function `cb` for handling error queue entries and logging messages. When `cb` is NULL errors are printed to STDERR (if available, else ignored) any log messages are ignored. Alternatively, OSSL_CMP_log_open(3) may be used to direct logging to STDOUT.

`OSSL_CMP_CTX_set_log_verbosity()` is a macro setting the OSSL_CMP_OPT_LOG_VERBOSITY context option to the given level.

`OSSL_CMP_CTX_print_errors()` outputs any entries in the OpenSSL error queue. It is similar to ERR_print_errors_cb() but uses the CMP log callback function if set in the `ctx` for uniformity with CMP logging if given. Otherwise it uses ERR_print_errors(3) to print to STDERR (unless OPENSSL_NO_STDIO is defined).

OSSL_CMP_CTX_set1_serverPath() sets the HTTP path of the CMP server on the host.

OSSL_CMP_CTX_set1_serverName() sets the given server Address (as IP or name) in the given OSSL_CMP_CTX structure.

`OSSL_CMP_CTX_set_serverPort()` sets the port of the CMP server to connect to. Port defaults to OSSL_CMP_DEFAULT_PORT = 80 if not set explicitly.

OSSL_CMP_CTX_set1_proxyName() sets the hostname of the HTTP proxy to be used for connecting to the CA server.

`OSSL_CMP_CTX_set_proxyPort()` sets the port of the HTTP proxy. Port defaults to OSSL_CMP_DEFAULT_PORT = 80 if not set explicitly.

`OSSL_CMP_CTX_set_http_cb()` sets the optional BIO connect/disconnect callback function, which has the prototype

     typedef BIO *(*HTTP_bio_cb_t) (BIO *bio, void *ctx, int connect, int detail);

The callback may modify the BIO bio provided by `OSSL_CMP_MSG_http_perform()`, whereby it may make use of a custom defined argument ctx stored in the OSSL_CMP_CTX by means of `OSSL_CMP_CTX_set_http_cb_arg()`. During connection establishment, just after calling `BIO_connect_retry()`, the function is invoked with the connect argument being 1 and the detail argument being 1 if HTTPS is requested, i.e., SSL/TLS should be enabled. On disconnect connect is 0 and detail is 1 in case no error occurred, else 0. For instance, on connect the function may prepend a TLS BIO to implement HTTPS; after disconnect it may do some diagnostic output and/or specific cleanup. The function should return NULL to indicate failure. After disconnect the modified BIO will be deallocated using `BIO_free_all()`.

`OSSL_CMP_CTX_set_http_cb_arg()` sets an argument, respectively a pointer to a structure containing arguments, optionally to be used by the http connect/disconnect callback function. arg is not consumed, and it must therefore explicitly be freed when not needed any more. arg may be NULL to clear the entry.

`OSSL_CMP_CTX_get_http_cb_arg()` gets the argument, respectively the pointer to a structure containing arguments, previously set by `OSSL_CMP_CTX_set_http_cb_arg()` or NULL if unset.

`OSSL_CMP_CTX_set_transfer_cb()` sets the message transfer callback function, which has the type

     typedef OSSL_CMP_MSG *(*OSSL_cmp_transfer_cb_t) (OSSL_CMP_CTX *ctx,
                                                      const OSSL_CMP_MSG *req);

Returns 1 on success, 0 on error.

Default is NULL, which implies the use of OSSL_CMP_MSG_http_perform(3). The callback should send the CMP request message it obtains via the req parameter and on success return the response. The transfer callback may make use of a custom defined argument stored in the ctx by means of `OSSL_CMP_CTX_set_transfer_cb_arg()`, which may be retrieved again through `OSSL_CMP_CTX_get_transfer_cb_arg()`.

`OSSL_CMP_CTX_set_transfer_cb_arg()` sets an argument, respectively a pointer to a structure containing arguments, optionally to be used by the transfer callback. arg is not consumed, and it must therefore explicitly be freed when not needed any more. arg may be NULL to clear the entry.

`OSSL_CMP_CTX_get_transfer_cb_arg()` gets the argument, respectively the pointer to a structure containing arguments, previously set by `OSSL_CMP_CTX_set_transfer_cb_arg()` or NULL if unset.

OSSL_CMP_CTX_set1_srvCert() pins the server certificate to be directly trusted (even if it is expired) for verifying response messages. The cert pointer is not consumed. It may be NULL to clear the entry.

OSSL_CMP_CTX_set1_expected_sender() sets the Distinguished Name (DN) expected to be given in the sender response for messages protected with MSG_SIG_ALG. This may be used to enforce that during validation of received messages the given DN matches the sender field of the PKIMessage header, which in turn is used to identify the server certificate. This can be used to ensure that only a particular entity is accepted to act as CMP server, and attackers are not able to use arbitrary certificates of a trusted PKI hierarchy to fraudulently pose as server. This defaults to the subject DN of the certificate set via OSSL_CMP_CTX_set1_srvCert(), if any.

OSSL_CMP_CTX_set0_trustedStore() sets the X509_STORE type certificate store containing trusted (root) CA certificates. The certificate store may also hold CRLs and a certificate verification callback function used for CMP server authentication. Any already existing store entry is freed. When given a NULL parameter the entry is cleared.

OSSL_CMP_CTX_get0_trustedStore() returns a pointer to the certificate store containing trusted root CA certificates, which may be empty if unset.

OSSL_CMP_CTX_set1_untrusted_certs() takes over a list of certificates containing non-trusted intermediate certs used for path construction in authentication of the CMP server and potentially others (TLS server, newly enrolled cert). The reference counts of those certificates handled successfully are increased.

OSSL_CMP_CTX_get0_untrusted_certs(OSSL_CMP_CTX *ctx) returns a pointer to the list of untrusted certs, which my be empty if unset.

OSSL_CMP_CTX_set1_clCert() sets the client certificate in the given OSSL_CMP_CTX structure. The client certificate will then be used by the functions to set the "sender" field for outgoing messages and it will be included in the extraCerts field.

OSSL_CMP_CTX_set1_pkey() sets the private key corresponding to the client certificate set with OSSL_CMP_CTX_set1_clCert() in the given CMP context. Used to create the protection in case of MSG_SIG_ALG.

OSSL_CMP_CTX_set1_referenceValue() sets the given referenceValue in the given ctx or clears it if the ref argument is NULL.

OSSL_CMP_CTX_set1_secretValue() sets the sec with the length len in the given ctx or clears it if the sec argument is NULL.

OSSL_CMP_CTX_set1_recipient() sets the recipient name that will be used in the PKIHeader of a request message, i.e. the X509 name of the (CA) server. Setting is overruled by subject of srvCert if set. If neither srvCert nor recipient are set, the recipient of the PKI message is determined in the following order: issuer, issuer of old cert (oldCert), issuer of client cert (clCert), else NULL-DN. When a response is received, its sender must match the recipient of the request.

OSSL_CMP_CTX_push0_geninfo_ITAV() adds itav to the stack in the ctx to be added to the GeneralInfo field of the CMP PKIMessage header of a request message sent with this context. Consumes the pointer to itav.

OSSL_CMP_CTX_set1_extraCertsOut() sets the stack of extraCerts that will be sent to remote.

OSSL_CMP_CTX_set0_newPkey() can be used to explicitly set the given EVP_PKEY structure as the private or public key to be certified in the CMP context. The priv parameter must be 0 if and only if the given key is a public key.

OSSL_CMP_CTX_get0_newPkey() gives the key to use for certificate enrollment dependent on fields of the CMP context structure: the newPkey (which may be a private or public key) if present, else the public key in the p10CSR if present, else the client private key. If the priv parameter is not 0 and the selected key does not have a private component then NULL is returned.

OSSL_CMP_CTX_set1_issuer() sets the name of the intended issuer that will be set in the CertTemplate, i.e., the X509 name of the CA server.

OSSL_CMP_CTX_set1_subjectName() sets the subject DN that will be used in the CertTemplate structure when requesting a new cert. For Key Update Requests (KUR), it defaults to the subject DN of the reference certificate, see OSSL_CMP_CTX_set1_oldCert(). This default is used for Initialization Requests (IR) and Certification Requests (CR) only if no SANs are set.

If clCert is not set (e.g. in case of IR with MSG_MAC_ALG), the subject DN is also used as sender of the PKI message.

OSSL_CMP_CTX_push1_subjectAltName() adds the given X509 name to the list of alternate names on the certificate template request. This cannot be used if any Subject Alternative Name extension is set via OSSL_CMP_CTX_set0_reqExtensions(). By default, unless OSSL_CMP_OPT_SUBJECTALTNAME_NODEFAULT has been set, the Subject Alternative Names are copied from the reference certificate, see OSSL_CMP_CTX_set1_oldCert().

If set and the subject DN is not set with OSSL_CMP_CTX_set1_subjectName(), then the certificate template of an IR and CR will not be filled with the default subject DN from the reference certificate (see OSSL_CMP_CTX_set1_oldCert(). If a subject DN is desired it needs to be set explicitly with OSSL_CMP_CTX_set1_subjectName().

OSSL_CMP_CTX_set0_reqExtensions() sets the X.509v3 extensions to be used in IR/CR/KUR.

`OSSL_CMP_CTX_reqExtensions_have_SAN()` returns 1 if the context contains a Subject Alternative Name extension, else 0 or -1 on error.

OSSL_CMP_CTX_push0_policy() adds the certificate policy info object to the X509_EXTENSIONS of the requested certificate template.

OSSL_CMP_CTX_set1_oldCert() sets the old certificate to be updated in Key Update Requests (KUR) or to be revoked in Revocation Requests (RR). It must be given for RR, else it defaults to clCert. The reference certificate determined in this way, if any, is also used for deriving default subject DN and Subject Alternative Names for IR, CR, and KUR. Its issuer, if any, is used as default recipient in the CMP message header.

OSSL_CMP_CTX_set1_p10CSR() sets the PKCS#10 CSR to be used in P10CR.

OSSL_CMP_CTX_push0_genm_ITAV() adds itav to the stack in the ctx which will be the body of a General Message sent with this context. Consumes the pointer to itav.

`OSSL_CMP_CTX_set_certConf_cb()` sets the callback used for evaluating the newly enrolled certificate before the library sends, depending on its result, a positive or negative certConf message to the server. The callback has type

     typedef int (*OSSL_cmp_certConf_cb_t) (OSSL_CMP_CTX *ctx, X509 *cert,
                                            int fail_info, const char **txt);

and should inspect the certificate it obtains via the cert parameter and may overrule the pre-decision given in the fail_info and *txt parameters. If it accepts the certificate it must return 0, indicating success. Else it must return a bit field reflecting PKIFailureInfo with at least one failure bit and may set the *txt output parameter to point to a string constant with more detail. The transfer callback may make use of a custom defined argument stored in the ctx by means of `OSSL_CMP_CTX_set_certConf_cb_arg()`, which may be retrieved again through `OSSL_CMP_CTX_get_certConf_cb_arg()`. Typically, the callback will check at least that the certificate can be verified using a set of trusted certificates. It also could compare the subject DN and other fields of the newly enrolled certificate with the certificate template of the request.

`OSSL_CMP_CTX_set_certConf_cb_arg()` sets an argument, respectively a pointer to a structure containing arguments, optionally to be used by the certConf callback. arg is not consumed, and it must therefore explicitly be freed when not needed any more. arg may be NULL to clear the entry.

`OSSL_CMP_CTX_get_certConf_cb_arg()` gets the argument, respectively the pointer to a structure containing arguments, previously set by `OSSL_CMP_CTX_set_certConf_cb_arg()`, or NULL if unset.

`OSSL_CMP_CTX_get_status()` returns the PKIstatus from the last received CertRepMessage or Revocation Response or error message, or -1 if unset.

OSSL_CMP_CTX_get0_statusString() returns the statusString from the last received CertRepMessage or Revocation Response or error message, or NULL if unset.

`OSSL_CMP_CTX_get_failInfoCode()` returns the error code from the failInfo field of the last received CertRepMessage or Revocation Response or error message. This is a bit field and the flags for it are specified in the header file <openssl/cmp.h >>. The flags start with OSSL_CMP_CTX_FAILINFO, for example: OSSL_CMP_CTX_FAILINFO_badAlg. Returns -1 if the failInfoCode field is unset.

OSSL_CMP_CTX_get0_newCert() returns the pointer to the newly obtained certificate in case it is available, else NULL.

OSSL_CMP_CTX_get1_caPubs() returns a pointer to a duplicate of the stack of X.509 certificates received in the caPubs field of last received certificate response message IP/CP/KUP.

OSSL_CMP_CTX_get1_extraCertsIn() returns a pointer to a duplicate of the stack of X.509 certificates received in the last received non-empty extraCerts field. Returns an empty stack if no extraCerts have been received in the current transaction.

OSSL_CMP_CTX_set1_transactionID() sets the given transaction ID in the given OSSL_CMP_CTX structure.

OSSL_CMP_CTX_set1_senderNonce() stores the last sent sender nonce in the ctx. This will be used to validate the recipNonce in incoming messages.

# NOTES

CMP is defined in RFC 4210 (and CRMF in RFC 4211).

# RETURN VALUES

`OSSL_CMP_CTX_free()` and `OSSL_CMP_CTX_print_errors()` do not return anything.

`OSSL_CMP_CTX_new()`, `OSSL_CMP_CTX_get_http_cb_arg()`, `OSSL_CMP_CTX_get_transfer_cb_arg()`, OSSL_CMP_CTX_get0_trustedStore(), OSSL_CMP_CTX_get0_untrusted_certs(), OSSL_CMP_CTX_get0_newPkey(), `OSSL_CMP_CTX_get_certConf_cb_arg()`, OSSL_CMP_CTX_get0_statusString(), OSSL_CMP_CTX_get0_newCert(), OSSL_CMP_CTX_get1_caPubs(), and OSSL_CMP_CTX_get1_extraCertsIn() return the intended pointer value as described above or NULL on error.

`OSSL_CMP_CTX_get_option()`, `OSSL_CMP_CTX_reqExtensions_have_SAN()`, `OSSL_CMP_CTX_get_status()`, and `OSSL_CMP_CTX_get_failInfoCode()` return the intended value as described above or -1 on error.

All other functions return 1 on success, 0 on error.

# EXAMPLES

The following code does an Initialization Request:

            cmp_ctx = OSSL_CMP_CTX_new();
            OSSL_CMP_CTX_set1_serverName(cmp_ctx, opt_serverName);
            OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, ref, ref_len);
            OSSL_CMP_CTX_set1_secretValue(cmp_ctx, sec, sec_len);
            OSSL_CMP_CTX_set0_newPkey(cmp_ctx, new_pkey, 1);
            OSSL_CMP_CTX_set1_caCert(cmp_ctx, ca_cert);

            initialClCert = OSSL_CMP_exec_IR_ses(cmp_ctx);

The following code does an Initialization Request using an external identity certificate (RFC 4210, Appendix E.7):

            cmp_ctx = OSSL_CMP_CTX_new();
            OSSL_CMP_CTX_set1_serverName(cmp_ctx, sname);
            OSSL_CMP_CTX_set1_clCert(cmp_ctx, cl_cert);
            OSSL_CMP_CTX_set1_pkey(cmp_ctx, pkey);
            OSSL_CMP_CTX_set0_newPkey(cmp_ctx, new_pkey, 1);
            OSSL_CMP_CTX_set1_caCert(cmp_ctx, ca_cert);

            initialClCert = OSSL_CMP_exec_IR_ses(cmp_ctx);

Here externalCert is an X509 certificate granted to the EE by another CA which is trusted by the current CA the code will connect to.

The following code does a Key Update Request:

            cmp_ctx = OSSL_CMP_CTX_new();
            OSSL_CMP_CTX_set1_serverName(cmp_ctx, sname);
            OSSL_CMP_CTX_set1_pkey(cmp_ctx, pkey);
            OSSL_CMP_CTX_set0_newPkey(cmp_ctx, new_pkey, 1);
            OSSL_CMP_CTX_set1_clCert(cmp_ctx, cl_cert);
            OSSL_CMP_CTX_set1_caCert(cmp_ctx, ca_cert);

            updatedClCert = OSSL_CMP_exec_KUR_ses(cmp_ctx);

The following code (which omits error handling) sends a General Message including, as an example, the id-it-signKeyPairTypes OID and prints info on the General Response contents.

        cmp_ctx = OSSL_CMP_CTX_new();
        OSSL_CMP_CTX_set1_serverName(cmp_ctx, sname);
        OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, ref, ref_len);
        OSSL_CMP_CTX_set1_secretValue(cmp_ctx, sec, sec_len);

        ASN1_OBJECT *type = OBJ_txt2obj("1.3.6.1.5.5.7.4.2", 1);
        OSSL_CMP_ITAV *itav = OSSL_CMP_ITAV_new(type, NULL);
        OSSL_CMP_CTX_push0_genm_ITAV(cmp_ctx, itav);

        STACK_OF(OSSL_CMP_ITAV) *itavs;
        itavs = OSSL_CMP_exec_GENM_ses(cmp_ctx);
        print_itavs(itavs);
        sk_OSSL_CMP_ITAV_pop_free(itavs, OSSL_CMP_ITAV_free);

# SEE ALSO

OSSL_CMP_exec_IR_ses(3), OSSL_CMP_exec_KUR_ses(3), OSSL_CMP_exec_GENM_ses(3)

# HISTORY

The OpenSSL CMP support was added in OpenSSL 3.0.

# COPYRIGHT

Copyright 2007-2019 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at https://www.openssl.org/source/license.html.