OSSL_CMP_CTX_NEW(3SSL) OpenSSL OSSL_CMP_CTX_NEW(3SSL)
NAME
OSSL_CMP_CTX_new, OSSL_CMP_CTX_free, OSSL_CMP_CTX_reinit,
OSSL_CMP_CTX_get0_libctx, OSSL_CMP_CTX_get0_propq,
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_server, OSSL_CMP_CTX_set_serverPort,
OSSL_CMP_CTX_set1_proxy, OSSL_CMP_CTX_set1_no_proxy,
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_trusted,
OSSL_CMP_CTX_set0_trustedStore, OSSL_CMP_CTX_get0_trusted,
OSSL_CMP_CTX_get0_trustedStore, OSSL_CMP_CTX_set1_untrusted,
OSSL_CMP_CTX_get0_untrusted, OSSL_CMP_CTX_set1_cert,
OSSL_CMP_CTX_build_cert_chain, 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_reset_geninfo_ITAVs, OSSL_CMP_CTX_get0_geninfo_ITAVs,
OSSL_CMP_CTX_set1_extraCertsOut, OSSL_CMP_CTX_set0_newPkey,
OSSL_CMP_CTX_get0_newPkey, OSSL_CMP_CTX_set1_issuer,
OSSL_CMP_CTX_set1_serialNumber, 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_certConf_cb, 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_validatedSrvCert,
OSSL_CMP_CTX_get0_newCert, OSSL_CMP_CTX_get1_newChain,
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(OSSL_LIB_CTX *libctx, const char *propq);
void OSSL_CMP_CTX_free(OSSL_CMP_CTX *ctx);
int OSSL_CMP_CTX_reinit(OSSL_CMP_CTX *ctx);
OSSL_LIB_CTX *OSSL_CMP_CTX_get0_libctx(const OSSL_CMP_CTX *ctx);
const char *OSSL_CMP_CTX_get0_propq(const 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(const OSSL_CMP_CTX *ctx);
/* message transfer: */
int OSSL_CMP_CTX_set1_serverPath(OSSL_CMP_CTX *ctx, const char *path);
int OSSL_CMP_CTX_set1_server(OSSL_CMP_CTX *ctx, const char *address);
int OSSL_CMP_CTX_set_serverPort(OSSL_CMP_CTX *ctx, int port);
int OSSL_CMP_CTX_set1_proxy(OSSL_CMP_CTX *ctx, const char *name);
int OSSL_CMP_CTX_set1_no_proxy(OSSL_CMP_CTX *ctx, const char *names);
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);
#define OSSL_CMP_CTX_set0_trusted OSSL_CMP_CTX_set0_trustedStore
int OSSL_CMP_CTX_set0_trustedStore(OSSL_CMP_CTX *ctx, X509_STORE *store);
#define OSSL_CMP_CTX_get0_trusted OSSL_CMP_CTX_get0_trustedStore
X509_STORE *OSSL_CMP_CTX_get0_trustedStore(const OSSL_CMP_CTX *ctx);
int OSSL_CMP_CTX_set1_untrusted(OSSL_CMP_CTX *ctx, STACK_OF(X509) *certs);
STACK_OF(X509) *OSSL_CMP_CTX_get0_untrusted(const OSSL_CMP_CTX *ctx);
/* client authentication: */
int OSSL_CMP_CTX_set1_cert(OSSL_CMP_CTX *ctx, X509 *cert);
int OSSL_CMP_CTX_build_cert_chain(OSSL_CMP_CTX *ctx, X509_STORE *own_trusted,
STACK_OF(X509) *candidates);
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, 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_reset_geninfo_ITAVs(OSSL_CMP_CTX *ctx);
STACK_OF(OSSL_CMP_ITAV)
*OSSL_CMP_CTX_get0_geninfo_ITAVs(const OSSL_CMP_CTX *ctx);
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_serialNumber(OSSL_CMP_CTX *ctx, const ASN1_INTEGER *sn);
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_certConf_cb(OSSL_CMP_CTX *ctx, X509 *cert, int fail_info,
const char **text);
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_validatedSrvCert(const OSSL_CMP_CTX *ctx);
X509 *OSSL_CMP_CTX_get0_newCert(const OSSL_CMP_CTX *ctx);
STACK_OF(X509) *OSSL_CMP_CTX_get1_newChain(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 testing and debugging purposes: */
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 an OSSL_CMP_CTX structure associated with
the library context libctx and property query string propq, both of
which may be NULL to select the defaults. It initializes the remaining
fields to their default values - for instance, the logging verbosity is
set to OSSL_CMP_LOG_INFO, the message timeout is set to 120 seconds, and
the proof-of-possession method is set to OSSL_CRMF_POPO_SIGNATURE.
OSSL_CMP_CTX_free() deallocates an OSSL_CMP_CTX structure. If the
argument is NULL, nothing is done.
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, newChain, caPubs, and
extraCertsIn) from the last executed transaction. It also clears any
ITAVs that were added by OSSL_CMP_CTX_push0_genm_ITAV(). All other
field values (i.e., CMP options) are retained for potential reuse.
OSSL_CMP_CTX_get0_libctx() returns the libctx argument that was used
when constructing ctx with OSSL_CMP_CTX_new(), which may be NULL.
OSSL_CMP_CTX_get0_propq() returns the propq argument that was used when
constructing ctx with OSSL_CMP_CTX_new(), which may be NULL.
OSSL_CMP_CTX_set_option() sets the given value for the given option
(e.g., OSSL_CMP_OPT_IMPLICIT_CONFIRM) 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 OSSL_CMP_log_open(3).
OSSL_CMP_OPT_KEEP_ALIVE
If the given value is 0 then HTTP connections are not kept open
after receiving a response, which is the default behavior for HTTP
1.0. If the value is 1 or 2 then persistent connections are
requested. If the value is 2 then persistent connections are
required, i.e., in case the server does not grant them an error
occurs. The default value is 1: prefer to keep the connection open.
OSSL_CMP_OPT_MSG_TIMEOUT
Number of seconds a CMP request-response message round trip is
allowed to take before a timeout error is returned. A value <= 0
means no limitation (waiting indefinitely). Default is to use the
OSSL_CMP_OPT_TOTAL_TIMEOUT setting.
OSSL_CMP_OPT_TOTAL_TIMEOUT
Maximum total number of seconds a transaction may take, including
polling etc. A value <= 0 means no limitation (waiting
indefinitely). Default is 0.
OSSL_CMP_OPT_USE_TLS
Use this option to indicate to the HTTP implementation whether TLS
is going to be used for the connection (resulting in HTTPS). The
value 1 indicates that TLS is used for client-side HTTP connections,
which needs to be implemented via a callback function set by
OSSL_CMP_CTX_set_http_cb(). The value 0 indicates that TLS is not
used. Default is -1 for backward compatibility: TLS is used by the
client side if and only if OSSL_CMP_CTX_set_http_cb_arg() sets a
non-NULL arg.
OSSL_CMP_OPT_VALIDITY_DAYS
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_POPO_METHOD
Select the proof of possession method to use. Possible values are:
OSSL_CRMF_POPO_NONE - ProofOfPossession field omitted,
which implies central key generation
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's pkey component of the CMP
context.
OSSL_CMP_OPT_DIGEST_ALGNID
The NID of the digest algorithm to be used in RFC 9810's MSG_SIG_ALG
for signature-based message protection and Proof-of-Possession
(POPO). Default is SHA256.
OSSL_CMP_OPT_OWF_ALGNID The NID of the digest algorithm to be used as
one-way function (OWF) for MAC-based message protection with password-
based MAC (PBM). See RFC 9810 section 5.1.3.1 for details. Default is
SHA256.
OSSL_CMP_OPT_MAC_ALGNID The NID of the MAC algorithm to be used for
message protection with PBM. Default is HMAC-SHA1, for backward
compatibility with 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_IMPLICIT_CONFIRM
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_DISABLE_CONFIRM
Do not confirm enrolled certificates, to cope with broken servers
not supporting implicit confirmation correctly. WARNING: This
setting leads to unspecified behavior and it is meant exclusively to
allow interoperability with server implementations violating RFC
9810.
OSSL_CMP_OPT_UNPROTECTED_SEND
Send request or response 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. WARNING: This setting
leads to unspecified behavior and it is meant exclusively to allow
interoperability with server implementations violating RFC 9810.
OSSL_CMP_OPT_IGNORE_KEYUSAGE
Ignore key usage restrictions in the signer's 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. This is a quirk
option added to support 3GPP TS 33.310.
Note that using this option is dangerous as the certificate obtained
this way has not been authenticated (at least not at CMP level).
Taking it over as a trust anchor implements trust-on-first-use
(TOFU).
OSSL_CMP_OPT_NO_CACHE_EXTRACERTS
Do not cache certificates received in the extraCerts CMP message
field. Otherwise they are stored to potentially help validate
further messages.
In any case, after successfully validating an incoming message, its
protection certificate (if any) is cached for reuse with validation
of subsequent messages. This is done not only for efficiency but
also to eliminate the need for the sender to include its certificate
and related chain in the extraCerts field of subsequent messages of
the same transaction.
OSSL_CMP_CTX_get_option() reads the current value of the given option
(e.g., OSSL_CMP_OPT_IMPLICIT_CONFIRM) 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(3) 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, also known as "CMP alias". The default is "/".
OSSL_CMP_CTX_set1_server() sets the given server address (which may be a
hostname or IP address or NULL) in the given ctx. If
OSSL_CMP_CTX_get_transfer_cb_arg() sets a non-NULL argument, this server
address information is used for diagnostic output only.
OSSL_CMP_CTX_set_serverPort() sets the port of the CMP server to connect
to. If not used or the port argument is 0 the default port applies,
which is 80 for HTTP and 443 for HTTPS. If
OSSL_CMP_CTX_get_transfer_cb_arg() sets a non-NULL argument, this server
port information is used for diagnostic output only.
OSSL_CMP_CTX_set1_proxy() sets the HTTP proxy to be used for connecting
to the given CMP server unless overruled by any "no_proxy" settings (see
below). If TLS is not used this defaults to the value of the
environment variable "http_proxy" if set, else "HTTP_PROXY". Otherwise
defaults to the value of "https_proxy" if set, else "HTTPS_PROXY". An
empty proxy string specifies not to use a proxy. Otherwise the format
is "[http[s]://][userinfo@]host[:port][/path][?query][#fragment]", where
any given userinfo, path, query, and fragment is ignored. If the host
string is an IPv6 address, it must be enclosed in "[" and "]". The
default port number is 80, or 443 in case "https:" is given.
OSSL_CMP_CTX_set1_no_proxy() sets the list of server hostnames not to
use an HTTP proxy for. The names may be separated by commas and/or
whitespace. Defaults to the environment variable "no_proxy" if set,
else "NO_PROXY".
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 *arg, int connect, int detail);
The callback may modify the bio provided by OSSL_CMP_MSG_http_perform(3)
as described for the bio_update_fn parameter of OSSL_HTTP_open(3). The
callback may make use of a custom defined argument arg, as described for
the arg parameter of OSSL_HTTP_open(3). The argument is stored in the
OSSL_CMP_CTX using OSSL_CMP_CTX_set_http_cb_arg(). See also the
OSSL_CMP_OPT_USE_TLS option described above.
OSSL_CMP_CTX_set_http_cb_arg() sets the argument, respectively a pointer
to a structure containing arguments such as an SSL_CTX structure,
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. If a non-NULL
argument is set, it is an error to use OSSL_CMP_CTX_set1_proxy() or
OSSL_CMP_CTX_set1_no_proxy() for setting non-NULL strings.
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);
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, else it must return NULL.
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() sets the expected server cert in ctx and
trusts it directly (even if it is expired) when verifying signed
response messages. This pins the accepted CMP server and results in
ignoring whatever may be set using OSSL_CMP_CTX_set0_trusted(). Any
previously set value is freed. The cert argument may be NULL to clear
the entry. If set, the subject of the certificate is also used as
default value for the recipient of CMP requests and as default value for
the expected sender of CMP responses.
OSSL_CMP_CTX_set1_expected_sender() sets the Distinguished Name (DN)
expected in the sender field of incoming CMP messages. Defaults to the
subject of the pinned server certificate, if any. This can be used to
make sure that only a particular entity is accepted as CMP message
signer, and attackers are not able to use arbitrary certificates of a
trusted PKI hierarchy to fraudulently pose as CMP server. Note that
this gives slightly more freedom than OSSL_CMP_CTX_set1_srvCert(), which
pins the server to the holder of a particular certificate, while the
expected sender name will continue to match after updates of the server
cert.
OSSL_CMP_CTX_set0_trusted() is an alias of the original
OSSL_CMP_CTX_set0_trustedStore(). It sets in the CMP context ctx the
certificate store of type X509_STORE containing trusted certificates,
typically of root CAs. This is ignored when a certificate is pinned
using OSSL_CMP_CTX_set1_srvCert(). The store may also hold CRLs and a
certificate verification callback function used for signature-based peer
authentication. Any store entry already set before is freed. When
given a NULL parameter the entry is cleared.
OSSL_CMP_CTX_get0_trusted() is an alias of the original
OSSL_CMP_CTX_get0_trustedStore(). It extracts from the CMP context ctx
the pointer to the currently set certificate store containing trust
anchors etc., or an empty store if unset.
OSSL_CMP_CTX_set1_untrusted() sets up a list of non-trusted certificates
of intermediate CAs that may be useful for path construction for the own
CMP signer certificate, for the own TLS certificate (if any), when
verifying peer CMP protection certificates, and when verifying newly
enrolled certificates. The reference counts of those certificates
handled successfully are increased. This list of untrusted certificates
in ctx will get augmented by extraCerts in received CMP messages unless
OSSL_CMP_OPT_NO_CACHE_EXTRACERTS is set.
OSSL_CMP_CTX_get0_untrusted() returns a pointer to the list of untrusted
certs in ctx, which may be empty if unset.
OSSL_CMP_CTX_set1_cert() sets the CMP signer certificate, also called
protection certificate, related to the private key used for signature-
based CMP message protection. Therefore the public key of this cert
must correspond to the private key set before or thereafter via
OSSL_CMP_CTX_set1_pkey(). When using signature-based protection of CMP
request messages this CMP signer certificate will be included first in
the extraCerts field. It serves as fallback reference certificate, see
OSSL_CMP_CTX_set1_oldCert(). The subject of this cert will be used as
the sender field of outgoing messages, while the subject of any cert set
via OSSL_CMP_CTX_set1_oldCert(), the subject of any PKCS#10 CSR set via
OSSL_CMP_CTX_set1_p10CSR(), and any value set via
OSSL_CMP_CTX_set1_subjectName() are used as fallback.
The cert argument may be NULL to clear the entry.
OSSL_CMP_CTX_build_cert_chain() builds a certificate chain for the CMP
signer certificate previously set in the ctx. It adds the optional
candidates, a list of intermediate CA certs that may already constitute
the targeted chain, to the untrusted certs that may already exist in the
ctx. Then the function uses this augmented set of certs for chain
construction. If own_trusted is NULL it builds the chain as far down as
possible and ignores any verification errors. Else the CMP signer
certificate must be verifiable where the chain reaches a trust anchor
contained in own_trusted. On success the function stores the resulting
chain in ctx for inclusion in the extraCerts field of signature-
protected messages. Calling this function is optional; by default a
chain construction is performed on demand that is equivalent to calling
this function with the candidates and own_trusted arguments being NULL.
OSSL_CMP_CTX_set1_pkey() sets the client's private key corresponding to
the CMP signer certificate set via OSSL_CMP_CTX_set1_cert(). This key
is used create signature-based protection (protectionAlg = MSG_SIG_ALG)
of outgoing messages unless a symmetric secret has been set via
OSSL_CMP_CTX_set1_secretValue(). The pkey argument may be NULL to clear
the entry.
OSSL_CMP_CTX_set1_secretValue() sets in ctx the byte string sec of
length len to use as pre-shared secret, or clears it if the sec argument
is NULL. If present, this secret is used to create MAC-based
authentication and integrity protection (rather than applying signature-
based protection) of outgoing messages and to verify authenticity and
integrity of incoming messages that have MAC-based protection
(protectionAlg = "MSG_MAC_ALG").
OSSL_CMP_CTX_set1_referenceValue() sets the given referenceValue ref
with length len in the given ctx or clears it if the ref argument is
NULL. According to RFC 9810 section 5.1.1, if no value for the sender
field in CMP message headers can be determined (i.e., no CMP signer
certificate and no subject DN is set via OSSL_CMP_CTX_set1_subjectName()
then the sender field will contain the NULL-DN and the senderKID field
of the CMP message header must be set. When signature-based protection
is used the senderKID will be set to the subjectKeyIdentifier of the CMP
signer certificate as far as present. If not present or when MAC-based
protection is used the ref value is taken as the fallback value for the
senderKID.
OSSL_CMP_CTX_set1_recipient() sets the recipient name that will be used
in the PKIHeader of CMP request messages, i.e. the X509 name of the (CA)
server.
The recipient field in the header of a CMP message is mandatory. If not
given explicitly the recipient is determined in the following order: the
subject of the CMP server certificate set using
OSSL_CMP_CTX_set1_srvCert(), the value set using
OSSL_CMP_CTX_set1_issuer(), the issuer of the certificate set using
OSSL_CMP_CTX_set1_oldCert(), the issuer of the CMP signer certificate,
as far as any of those is present, else the NULL-DN as last resort.
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.
OSSL_CMP_CTX_reset_geninfo_ITAVs() clears any ITAVs that were added by
OSSL_CMP_CTX_push0_geninfo_ITAV().
OSSL_CMP_CTX_get0_geninfo_ITAVs() returns the list of ITAVs set in ctx
for inclusion in the generalInfo field of the CMP PKIMessage header of
requests or NULL if not set.
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's 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_serialNumber() sets the serial number optionally used
to select the certificate to be revoked in Revocation Requests (RR).
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. The subjectName is also used as fallback for the sender
field of outgoing CMP messages if no reference certificate is available.
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. 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).
For RR, this is ignored if an issuer name and a serial number are
provided using OSSL_CMP_CTX_set1_issuer() and
OSSL_CMP_CTX_set1_serialNumber(), respectively. For IR/CR/KUR this sets
the reference certificate, which otherwise defaults to the CMP signer
certificate. The reference certificate determined this way, if any, is
used for providing default public key, subject DN, Subject Alternative
Names, and issuer DN entries in the requested certificate template of
IR/CR/KUR messages.
The subject of the reference certificate is used as the sender field
value in CMP message headers. Its issuer is used as default recipient
in CMP message headers.
OSSL_CMP_CTX_set1_p10CSR() sets the PKCS#10 CSR to use in P10CR
messages. If such a CSR is provided, its subject and public key fields
are also used as fallback values for the certificate template of
IR/CR/KUR/RR messages, and any extensions included are added to the
template of IR/CR/KUR messages.
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.
OSSL_CMP_certConf_cb() is the default certificate confirmation callback
function. If the callback argument is not NULL it must point to a trust
store. In this case the function checks that the newly enrolled
certificate can be verified using this trust store and untrusted
certificates from the ctx, which have been augmented by the list of
extraCerts received. During this verification, any certificate status
checking is disabled. If the callback argument is NULL the function
tries building an approximate chain as far as possible using the same
untrusted certificates from the ctx, and if this fails it takes the
received extraCerts as fallback. The resulting cert chain can be
retrieved using OSSL_CMP_CTX_get1_newChain(). This chain excludes the
leaf certificate, i.e., the newly enrolled certificate. Also the trust
anchor (the root certificate) is not included.
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 for client contexts the PKIstatus from
the last received CertRepMessage or Revocation Response or error
message: =item OSSL_CMP_PKISTATUS_accepted on successful receipt of a
GENP message:
OSSL_CMP_PKISTATUS_request
if an IR/CR/KUR/RR/GENM request message could not be produced,
OSSL_CMP_PKISTATUS_trans
on a transmission error or transaction error for this type of
request, and
OSSL_CMP_PKISTATUS_unspecified
if no such request was attempted or OSSL_CMP_CTX_reinit() has been
called.
For server contexts it returns OSSL_CMP_PKISTATUS_trans if a transaction
is open, otherwise OSSL_CMP_PKISTATUS_unspecified.
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, or -1 if no such response was received or
OSSL_CMP_CTX_reinit() has been called. 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_validatedSrvCert() returns the successfully validated
certificate, if any, that the CMP server used in the current transaction
for signature-based response message protection, or NULL if the server
used MAC-based protection. The value is relevant only at the end of a
successful transaction. It may be used to check the authorization of
the server based on its cert.
OSSL_CMP_CTX_get0_newCert() returns the pointer to the newly obtained
certificate in case it is available, else NULL.
OSSL_CMP_CTX_get1_newChain() returns a pointer to a duplicate of the
stack of X.509 certificates computed by OSSL_CMP_certConf_cb() (if this
function has been called) on the last received certificate response
message IP/CP/KUP.
OSSL_CMP_CTX_get1_caPubs() returns a pointer to a duplicate of the list
of X.509 certificates in the caPubs field of the last received
certificate response message (of type IP, CP, or KUP), or an empty stack
if no caPubs have been received in the current transaction.
OSSL_CMP_CTX_get1_extraCertsIn() returns a pointer to a duplicate of the
list of X.509 certificates contained in the extraCerts field of the last
received response message (except for pollRep and PKIConf), or 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 9810 (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_get0_libctx(),
OSSL_CMP_CTX_get0_propq(), OSSL_CMP_CTX_get_http_cb_arg(),
OSSL_CMP_CTX_get_transfer_cb_arg(), OSSL_CMP_CTX_get0_trusted(),
OSSL_CMP_CTX_get0_untrusted(), OSSL_CMP_CTX_get0_geninfo_ITAVs(),
OSSL_CMP_CTX_get0_newPkey(), OSSL_CMP_CTX_get_certConf_cb_arg(),
OSSL_CMP_CTX_get0_statusString(), OSSL_CMP_CTX_get0_validatedSrvCert(),
OSSL_CMP_CTX_get0_newCert(), OSSL_CMP_CTX_get0_newChain(),
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.
OSSL_CMP_certConf_cb() returns fail_info if it is not equal to 0, else 0
on successful validation, or else a bit field with the
OSSL_CMP_PKIFAILUREINFO_incorrectData bit set.
All other functions, including OSSL_CMP_CTX_reinit() and
OSSL_CMP_CTX_reset_geninfo_ITAVs(), return 1 on success, 0 on error.
EXAMPLES
The following code omits error handling.
Set up a CMP client context for sending requests and verifying
responses:
cmp_ctx = OSSL_CMP_CTX_new();
OSSL_CMP_CTX_set1_server(cmp_ctx, name_or_address);
OSSL_CMP_CTX_set1_serverPort(cmp_ctx, port_string);
OSSL_CMP_CTX_set1_serverPath(cmp_ctx, path_or_alias);
OSSL_CMP_CTX_set0_trusted(cmp_ctx, ts);
Set up symmetric credentials for MAC-based message protection such as
PBM:
OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, ref, ref_len);
OSSL_CMP_CTX_set1_secretValue(cmp_ctx, sec, sec_len);
Set up the details for certificate requests:
OSSL_CMP_CTX_set1_subjectName(cmp_ctx, name);
OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, initialKey);
Perform an Initialization Request transaction:
initialCert = OSSL_CMP_exec_IR_ses(cmp_ctx);
Reset the transaction state of the CMP context and the credentials:
OSSL_CMP_CTX_reinit(cmp_ctx);
OSSL_CMP_CTX_set1_referenceValue(cmp_ctx, NULL, 0);
OSSL_CMP_CTX_set1_secretValue(cmp_ctx, NULL, 0);
Perform a Certification Request transaction, making use of the new
credentials:
OSSL_CMP_CTX_set1_cert(cmp_ctx, initialCert);
OSSL_CMP_CTX_set1_pkey(cmp_ctx, initialKey);
OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, curentKey);
currentCert = OSSL_CMP_exec_CR_ses(cmp_ctx);
Perform a Key Update Request, signed using the cert (and key) to be
updated:
OSSL_CMP_CTX_reinit(cmp_ctx);
OSSL_CMP_CTX_set1_cert(cmp_ctx, currentCert);
OSSL_CMP_CTX_set1_pkey(cmp_ctx, currentKey);
OSSL_CMP_CTX_set0_newPkey(cmp_ctx, 1, updatedKey);
currentCert = OSSL_CMP_exec_KUR_ses(cmp_ctx);
currentKey = updatedKey;
Perform a General Message transaction including, as an example, the id-
it-signKeyPairTypes OID and prints info on the General Response
contents:
OSSL_CMP_CTX_reinit(cmp_ctx);
ASN1_OBJECT *type = OBJ_txt2obj("1.3.6.1.5.5.7.4.2", 1);
OSSL_CMP_ITAV *itav = OSSL_CMP_ITAV_create(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_CR_ses(3),
OSSL_CMP_exec_KUR_ses(3), OSSL_CMP_exec_GENM_ses(3),
OSSL_CMP_exec_certreq(3), OSSL_CMP_MSG_http_perform(3),
ERR_print_errors_cb(3), OSSL_HTTP_open(3)
HISTORY
The OpenSSL CMP support was added in OpenSSL 3.0.
OSSL_CMP_CTX_get0_trustedStore() was renamed to
OSSL_CMP_CTX_get0_trusted() and OSSL_CMP_CTX_set0_trustedStore() was
renamed to OSSL_CMP_CTX_set0_trusted(), using macros, while keeping the
old names for backward compatibility, in OpenSSL 3.2.
OSSL_CMP_CTX_reset_geninfo_ITAVs() was added in OpenSSL 3.0.8.
OSSL_CMP_CTX_set1_serialNumber(), OSSL_CMP_CTX_get0_libctx(),
OSSL_CMP_CTX_get0_propq(), and OSSL_CMP_CTX_get0_validatedSrvCert() were
added in OpenSSL 3.2.
OSSL_CMP_CTX_get0_geninfo_ITAVs() and the
OSSL_CMP_OPT_NO_CACHE_EXTRACERTS option were added in OpenSSL 3.3.
Support for central key generation, requested via OSSL_CRMF_POPO_NONE,
was added in OpenSSL 3.5.
COPYRIGHT
Copyright 2007-2026 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>.
3.5.7 2026-06-09 OSSL_CMP_CTX_NEW(3SSL)
Generated by dwww version 1.16 on Fri Oct 2 04:31:28 CEST 2026.