openssl-cmp(1ssl)

NAME#

openssl-cmp - Certificate Management Protocol (CMP, RFCs 9810 and 9811) application

SYNOPSIS#

opensslcmp [-help] [-configfilename] [-sectionnames] [-verbositylevel]

Generic message options:

[-cmdir|cr|kur|p10cr|rr|genm] [-infotypename] [-profilename] [-geninfovalues] [-templatefilename] [-keyspecfilename]

Certificate enrollment options:

[-newkeyfilename|uri] [-newkeypassarg] [-centralkeygen [-newkeyoutfilename] [-subjectname] [-daysnumber] [-reqextsname] [-sansspec] [-san_nodefault] [-policiesname] [-policy_oidsnames] [-policy_oids_critical] [-poponumber] [-csrfilename] [-out_trustedfilenames|uris] [-implicit_confirm] [-disable_confirm] [-certoutfilename] [-chainoutfilename]

Certificate enrollment and revocation options:

[-oldcertfilename|uri] [-issuername] [-serialnumber] [-revreasonnumber]

Message transfer options:

[-server[http[s]://][userinfo@]host[:port][/path][?query][#fragment]] [-proxy[http[s]://][userinfo@]host[:port][/path][?query][#fragment]] [-no_proxyaddresses] [-recipientname] [-pathremote_path] [-keep_alivevalue] [-msg_timeoutseconds] [-total_timeoutseconds]

Server authentication options:

[-trustedfilenames|uris] [-untrustedfilenames|uris] [-srvcertfilename|uri] [-expect_sendername] [-ignore_keyusage] [-unprotected_errors] [-no_cache_extracerts] [-srvcertoutfilename] [-extracertsoutfilename] [-cacertsoutfilename] [-oldwitholdfilename] [-newwithnewfilename] [-newwitholdfilename] [-oldwithnewfilename] [-crlcertfilename] [-oldcrlfilename] [-crloutfilename]

Client authentication and protection options:

[-refvalue] [-secretarg] [-certfilename|uri] [-own_trustedfilenames|uris] [-keyfilename|uri] [-keypassarg] [-digestname] [-macname] [-extracertsfilenames|uris] [-unprotected_requests]

Credentials format options:

[-certformPEM|DER] [-crlformPEM|DER] [-keyformPEM|DER|P12|ENGINE] [-otherpassarg] [-engineid] [-providername] [-provider-pathpath] [-provparam[name:]key=value] [-propquerypropq]

Random state options:

[-randfiles] [-writerandfile]

TLS connection options:

[-tls_used] [-tls_certfilename|uri] [-tls_keyfilename|uri] [-tls_keypassarg] [-tls_extrafilenames|uris] [-tls_trustedfilenames|uris] [-tls_hostname]

Client-side debugging options:

[-batch] [-repeatnumber] [-reqinfilenames] [-reqin_new_tid] [-reqoutfilenames] [-reqout_onlyfilename] [-rspinfilenames] [-rspoutfilenames] [-use_mock_srv]

Mock server options:

[-portnumber] [-max_msgsnumber] [-srv_refvalue] [-srv_secretarg] [-srv_certfilename|uri] [-srv_keyfilename|uri] [-srv_keypassarg] [-srv_trustedfilenames|uris] [-srv_untrustedfilenames|uris] [-ref_certfilename|uri] [-rsp_certfilename|uri] [-rsp_keyfilename|uri] [-rsp_keypassfilename|uri] [-rsp_crlfilename|uri] [-rsp_extracertsfilenames|uris] [-rsp_capubsfilenames|uris] [-rsp_newwithnewfilename|uri] [-rsp_newwitholdfilename|uri] [-rsp_oldwithnewfilename|uri] [-poll_countnumber] [-check_afternumber] [-grant_implicitconf] [-pkistatusnumber] [-failurenumber] [-failurebitsnumber] [-statusstringarg] [-send_error] [-send_unprotected] [-send_unprot_err] [-accept_unprotected] [-accept_unprot_err] [-accept_raverified]

Certificate verification options, for both CMP and TLS:

[-allow_proxy_certs] [-attimetimestamp] [-no_check_time] [-check_ss_sig] [-crl_check] [-crl_check_all] [-explicit_policy] [-extended_crl] [-ignore_critical] [-inhibit_any] [-inhibit_map] [-partial_chain] [-policyarg] [-policy_check] [-policy_print] [-purposepurpose] [-suiteB_128] [-suiteB_128_only] [-suiteB_192] [-trusted_first] [-no_alt_chains] [-use_deltas] [-auth_levelnum] [-verify_depthnum] [-verify_emailemail] [-verify_hostnamehostname] [-verify_ipip] [-verify_namename] [-x509_strict] [-issuer_checks]

DESCRIPTION#

The cmp command is a client implementation for the Certificate Management Protocol (CMP) as defined in RFCs 9810 and its HTTP(S) transfer as defined in RFC 9811. It can be used to request certificates from a CA server, update their certificates, request certificates to be revoked, and perform other types of CMP requests.

OPTIONS#

-help

Display a summary of all options

-configfilename

Configuration file to use. An empty string "" means none. Default filename is from the environment variable "OPENSSL_CONF".

-sectionnames

Multiple section names may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Contents of sections named later may override contents of sections named before. In any case, as usual, the "[default]" section and finally the unnamed section (as far as present) can provide per-option fallback values.

-verbositylevel

Level of verbosity for logging, error output, etc. 0 = EMERG, 1 = ALERT, 2 = CRIT, 3 = ERR, 4 = WARN, 5 = NOTE, 6 = INFO, 7 = DEBUG, 8 = TRACE. Defaults to 6 = INFO.

Generic message options#

-cmdir|cr|kur|p10cr|rr|genm

CMP command to execute. Currently implemented commands are:

ir   - Initialization Request

cr   - Certificate Request

p10cr - PKCS#10 Certification Request (for legacy support)

kur   - Key Update Request

rr   - Revocation Request

genm - General Message

ir requests initialization of an end entity into a PKI hierarchy by issuing a first certificate.

cr requests issuing an additional certificate for an end entity already initialized to the PKI hierarchy.

p10cr requests issuing an additional certificate similarly to cr but using legacy PKCS#10 CSR format.

kur requests a (key) update for an existing certificate.

rr requests revocation of an existing certificate.

genm requests information using a General Message, where optionally included InfoTypeAndValues may be used to state which info is of interest. Upon receipt of the General Response, information about all received ITAV infoTypes is printed to stdout.

-infotypename

Set InfoType name to use for requesting specific info in genm, e.g., "signKeyPairTypes". There is specific support for "caCerts", "rootCaCert", "certReqTemplate", and "crlStatusList" (CRL update retrieval).

-profilename

Name of a certificate profile to place in the PKIHeader generalInfo field of request messages.

-geninfovalues

A comma-separated list of InfoTypeAndValue to place in the generalInfo field of the PKIHeader of requests messages. Each InfoTypeAndValue gives an OID and an integer or string value of the form OID:int:number or OID:str:text, e.g., '1.2.3.4:int:56789, id-kp:str:name'.

-templatefilename

The file to save any CRMF certTemplate in DER format received in a genp message with id-it-certReqTemplate.

-keyspecfilename

Note: any keySpec field contents received are logged as INFO.

Certificate enrollment options#

-newkeyfilename|uri

The public portion of the key is placed in the certification request.

Unless -cmdp10cr, -popo-1, or -popo0 is given, the private key will be needed as well to provide the proof of possession (POPO), where the -key option may provide a fallback.

-newkeypassarg

For more information about the format of arg see openssl-passphrase-options(1).

-centralkeygen

Request central key generation for certificate enrollment. This applies to -cmdir|cr|kur|p10cr.

-newkeyoutfilename

File to save centrally generated private key, in PEM format.

-subjectname

If provided and neither of -cert, -oldcert, or -csr is given, the subject DN is used as fallback sender of outgoing CMP messages.

The argument must be formatted as /type0=value0/type1=value1/type2=.... Special characters may be escaped by "\" (backslash); whitespace is retained. Empty values are permitted, but the corresponding type will not be included. Giving a single "/" will lead to an empty sequence of RDNs (a NULL-DN). Multi-valued RDNs can be formed by placing a "+" character instead of a "/" between the AttributeValueAssertions (AVAs) that specify the members of the set. Example:

"/DC=org/DC=OpenSSL/DC=users/UID=123456+CN=John Doe"

-daysnumber

Number of days the new certificate is requested to be valid for, counting from the current time of the host. Also triggers the explicit request that the validity period starts from the current time (as seen by the host).

-reqextsname

Name of section in OpenSSL config file defining certificate request extensions. If the -csr option is present, these extensions augment the extensions contained the given PKCS#10 CSR, overriding any extensions with same OIDs.

-sansspec

One or more IP addresses, email addresses, DNS names, or URIs separated by commas or whitespace (where in the latter case the whole argument must be enclosed in "...") to add as Subject Alternative Name(s) (SAN) certificate request extension. If the special element "critical" is given the SANs are flagged as critical. Cannot be used if any Subject Alternative Name extension is set via -reqexts.

-san_nodefault

When Subject Alternative Names are not given via -sans nor defined via -reqexts, they are copied by default from the reference certificate (see -oldcert). This can be disabled by giving the -san_nodefault option.

-policiesname

Name of section in OpenSSL config file defining policies to be set as certificate request extension. This option cannot be used together with -policy_oids.

-policy_oidsnames

One or more OID(s), separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "...") to add as certificate policies request extension. This option cannot be used together with -policies.

-policy_oids_critical

Flag the policies given with -policy_oids as critical.

-poponumber

Note that a signature-based POPO can only be produced if a private key is provided via the -newkey or -key options.

-csrfilename

When used with -cmdir, cr, or kur, it is transformed into the respective regular CMP request. In this case, a private key must be provided (with -newkey or -key) for the proof of possession (unless -popo-1 or -popo0 is used) and the respective public key is placed in the certification request (rather than taking over the public key contained in the PKCS#10 CSR).

PKCS#10 CSR input may also be used with -cmdrr to specify the certificate to be revoked via the included subject name and public key. Its subject is used as fallback sender in CMP message headers if -cert and -oldcert are not given.

-out_trustedfilenames|uris

Multiple sources may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Each source may contain multiple certificates.

The certificate verification options -verify_hostname, -verify_ip, and -verify_email only affect the certificate verification enabled via this option.

-implicit_confirm

Request implicit confirmation of newly enrolled certificates.

-disable_confirm

Do not send certificate confirmation message for newly enrolled certificate without requesting implicit confirmation to cope with broken servers not supporting implicit confirmation correctly. WARNING: This leads to behavior violating RFC 9810.

-certoutfilename

The file where any newly enrolled certificate should be saved.

-chainoutfilename

If the -certout option is given, too, with equal filename argument, then the file produced contains both outputs concatenated: the newly enrolled certificate followed by its chain.

Certificate enrollment and revocation options#

-oldcertfilename|uri

The reference certificate, if any, is also used for deriving default subject DN and Subject Alternative Names and the default issuer entry in the requested certificate template of an IR/CR/KUR. Its public key is used as a fallback in the template of certification requests. Its subject is used as sender of outgoing messages if -cert is not given. Its issuer is used as default recipient in CMP message headers if neither -recipient, -srvcert, nor -issuer is given.

-issuername

If provided and neither -recipient nor -srvcert is given, the issuer DN is used as fallback recipient of outgoing CMP messages.

The argument must be formatted as /type0=value0/type1=value1/type2=.... For details see the description of the -subject option.

-serialnumber

Specify the Serial number of certificate to be revoked in revocation request. The serial number can be decimal or hex (if preceded by "0x")

-revreasonnumber

Reason numbers defined in RFC 5280 are:

bash

   CRLReason ::= ENUMERATED {
        unspecified             (0),
        keyCompromise           (1),
        cACompromise            (2),
        affiliationChanged      (3),
        superseded              (4),
        cessationOfOperation    (5),
        certificateHold         (6),
        -- value 7 is not used
        removeFromCRL           (8),
        privilegeWithdrawn      (9),
        aACompromise           (10)
    }

Message transfer options#

-server[http[s]://][userinfo@]host[:port][/path][?query][#fragment]

This option excludes -port and -use_mock_srv. It is ignored if -rspin is given with enough filename arguments.

If the scheme "https" is given, the -tls_used option is implied. When TLS is used, the default port is 443, otherwise 80. The optional userinfo and fragment components are ignored. Any given query component is handled as part of the path component. If a path is included it provides the default value for the -path option.

-proxy[http[s]://][userinfo@]host[:port][/path][?query][#fragment]

The HTTP(S) proxy server to use for reaching the CMP server unless -no_proxy applies, see below. If the host string is an IPv6 address, it must be enclosed in "[" and "]". The proxy port defaults to 80 or 443 if the scheme is "https"; apart from that the optional "http://" or "https://" prefix is ignored (note that using TLS may be required by -tls_used or -server with the prefix "https"), as well as any path, userinfo, and query, and fragment components. Defaults to the environment variable "http_proxy" if set, else "HTTP_PROXY" in case no TLS is used, otherwise "https_proxy" if set, else "HTTPS_PROXY". This option is ignored if -server is not given.

-no_proxyaddresses

List of IP addresses and/or DNS names of servers not to use an HTTP(S) proxy for, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Default is from the environment variable "no_proxy" if set, else "NO_PROXY". This option is ignored if -server is not given.

-recipientname

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 given with the -srvcert option, the -issuer option, the issuer of the certificate given with the -oldcert option, the issuer of the CMP client certificate (-cert option), as far as any of those is present, else the NULL-DN as last resort.

The argument must be formatted as /type0=value0/type1=value1/type2=.... For details see the description of the -subject option.

-pathremote_path

HTTP path at the CMP server (aka CMP alias) to use for POST requests. Defaults to any path given with -server, else "/".

-keep_alivevalue

If the given value is 0 then HTTP connections are closed after each response (which would be the default behavior of HTTP 1.0) even if a CMP transaction needs more than one round trip. If the value is 1 or 2 then for each transaction a persistent connection is requested. If the value is 2 then a persistent connection is required, i.e., an error occurs if the server does not grant it. The default value is 1, which means preferring to keep the connection open.

-msg_timeoutseconds

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 -total_timeout setting.

-total_timeoutseconds

Maximum total number of seconds a transaction may take, including polling etc. A value <= 0 means no limitation (waiting indefinitely). Default is 0.

Server authentication options#

-trustedfilenames|uris

If none of -trusted, -srvcert, and -secret is given, message validation errors will be thrown unless -unprotected_errors permits an exception.

Multiple sources may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Each source may contain multiple certificates.

The certificate verification options -verify_hostname, -verify_ip, and -verify_email have no effect on the certificate verification enabled via this option.

-untrustedfilenames|uris

Multiple sources may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Each source may contain multiple certificates.

-srvcertfilename|uri

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.

-expect_sendername

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 a CMP server. Note that this option gives slightly more freedom than setting the -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.

The argument must be formatted as /type0=value0/type1=value1/type2=.... For details see the description of the -subject option.

-ignore_keyusage

Ignore key usage restrictions in CMP signer certificates when validating signature-based protection of incoming CMP messages. By default, "digitalSignature" must be allowed by CMP signer certificates. This option applies to both CMP clients and the mock server.

-unprotected_errors

Accept missing or invalid protection of negative responses from the server. This applies to the following message types and contents:

• error messages

• negative certificate responses (IP/CP/KUP)

• negative revocation responses (RP)

• negative PKIConf messages

WARNING: This setting leads to unspecified behavior and it is meant exclusively to allow interoperability with server implementations violating RFC 9810, e.g.:

• section 5.1.3.1 allows exceptions from protecting only for special cases: "There MAY be cases in which the PKIProtection BIT STRING is deliberately not used to protect a message [...] because other protection, external to PKIX, will be applied instead."

• section 5.3.21 is clear on ErrMsgContent: "The CA MUST always sign it with a signature key."

• appendix D.4 shows PKIConf message having protection

-no_cache_extracerts

Do not cache certificates in the extraCerts field of CMP messages received. By default, they are kept as they may be helful for validating further messages. This option applies to both CMP clients and the mock server.

-srvcertoutfilename

The file where to save the successfully validated certificate, if any, that the CMP server used for signature-based response message protection. If there is no such certificate, typically because the protection was MAC-based, this is indicated by deleting the file (if it existed).

-extracertsoutfilename

The file where to save the list of certificates contained in the extraCerts field of the last received response message that is not a pollRep nor PKIConf.

-cacertsoutfilename

The file where to save the list of CA certificates contained in the caPubs field if a positive certificate response (i.e., IP, CP, or KUP) message was received or contained in a general response (genp) message with infoType "caCerts".

-oldwitholdfilename

The root CA certificate to include in a genm request of infoType "rootCaCert". If present and the optional oldWithNew certificate is received, it is verified using the newWithNew certificate as the (only) trust anchor.

-newwithnewfilename

Any received newWithNew certificate is verified using any received newWithOld certificate as untrusted intermediate certificate and the certificate provided with -oldwithold as the (only) trust anchor, or if not provided, using the certificates given with the -trusted option.

WARNING: The newWithNew certificate is meant to be a certificate that will be trusted. The trust placed in it cannot be stronger than the trust placed in the -oldwithold certificate if present, otherwise it cannot be stronger than the weakest trust placed in any of the -trusted certificates.

-newwitholdfilename

The file to save any newWithOld certificate received in a genp message of infoType "rootCaKeyUpdate". If on success no such cert was received, this is indicated by deleting the file.

-oldwithnewfilename

The file to save any oldWithNew certificate received in a genp message of infoType "rootCaKeyUpdate". If on success no such cert was received, this is indicated by deleting the file.

-crlcertfilename

Certificate to derive CRL issuer data for the source field when obtaining a CRL in a genm request with infoType "crlStatusList". Any available distribution point name is preferred over issuer names.

-oldcrlfilename

The CRL to obtain an update for in a genm request with infoType "crlStatusList". Unless the -crlcert option is provided as well, the given CRL is used for deriving CRL issuer data for the source field. Any available distribution point name is preferred over issuer names. If the CRL contains a thisUpdate field, its value is copied to the request.

-crloutfilename

The file to save any CRL received in a genp message of infoType "crls". If on success no such CRL was received, this is indicated by deleting the file.

Client authentication options#

-refvalue

Reference number/string/value to use as fallback senderKID; this is required if no sender name can be determined from the -cert or <-subject> options and is typically used when authenticating with pre-shared key (password-based MAC).

-secretarg

For more information about the format of arg see openssl-passphrase-options(1).

-certfilename|uri

The subject and the public key contained in this certificate serve as fallback values in the certificate template of IR/CR/KUR messages.

The subject of this certificate will be used as sender of outgoing CMP messages, while the subject of -oldcert or -subjectName may provide fallback values.

The issuer of this certificate is used as one of the recipient fallback values and as fallback issuer entry in the certificate template of IR/CR/KUR messages.

When performing signature-based message protection, this "protection certificate", also called "signer certificate", will be included first in the extraCerts field of outgoing messages and the signature is done with the corresponding key. In Initialization Request (IR) messages this can be used for authenticating using an external entity certificate as defined in appendix D.7 of RFC 9810.

For Key Update Request (KUR) messages this is also used as the certificate to be updated if the -oldcert option is not given.

If the file includes further certs, they are appended to the untrusted certs because they typically constitute the chain of the client certificate, which is included in the extraCerts field in signature-protected request messages.

-own_trustedfilenames|uris

Multiple sources may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Each source may contain multiple certificates.

The certificate verification options -verify_hostname, -verify_ip, and -verify_email have no effect on the certificate verification enabled via this option.

-keyfilename|uri

It is also used as a fallback for the -newkey option with IR/CR/KUR messages.

-keypassarg

For more information about the format of arg see openssl-passphrase-options(1).

-digestname

Specifies name of supported digest to use in RFC 9810's MSG_SIG_ALG and as the one-way function (OWF) in "MSG_MAC_ALG". If applicable, this is used for message protection and proof-of-possession (POPO) signatures. To see the list of supported digests, use "openssl list -digest-commands". Defaults to "sha256".

-macname

Specifies the name of the MAC algorithm in "MSG_MAC_ALG". To get the names of supported MAC algorithms use "openssl list -mac-algorithms" and possibly combine such a name with the name of a supported digest algorithm, e.g., hmacWithSHA256. Defaults to "hmac-sha1", for backward compatibility with RFC 4210.

-extracertsfilenames|uris

Multiple sources may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Each source may contain multiple certificates.

-unprotected_requests

Send request messages without CMP-level protection.

Credentials format options#

-certformPEM|DER

File format to use when saving a certificate to a file. Default value is PEM.

-crlformPEM|DER

File format to use when saving a CRL to a file. Default value is DER. DER format is preferred because it enables more efficient storage of large CRLs.

-keyformPEM|DER|P12|ENGINE

The format of the key input; unspecified by default. See "Format Options" in openssl(1) for details.

-otherpassarg

For more information about the format of arg see openssl-passphrase-options(1).

-engineid

As an alternative to using this combination:

bash

    -engine {engineid} -key {keyid} -keyform ENGINE

... it's also possible to just give the key ID in URI form to -key, like this:

bash

    -key org.openssl.engine:{engineid}:{keyid}

This applies to all options specifying keys: -key, -newkey, and -tls_key.

Provider options#

-providername

-provider-pathpath

-provparam[name:]key=value

-propquerypropq

See "Provider Options" in openssl(1), provider(7), and property(7).

Random state options#

-randfiles, -writerandfile

See "Random State Options" in openssl(1) for details.

TLS connection options#

-tls_used

The following TLS-related options are ignored if TLS is not used.

-tls_certfilename|uri

Client's TLS certificate to use for authenticating to the TLS server. If the source includes further certs they are used (along with -untrusted certs) for constructing the client cert chain provided to the TLS server.

-tls_keyfilename|uri

Private key for the client's TLS certificate.

-tls_keypassarg

For more information about the format of arg see openssl-passphrase-options(1).

-tls_extrafilenames|uris

Extra certificates to provide to the TLS server during handshake.

-tls_trustedfilenames|uris

Multiple sources may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "..."). Each source may contain multiple certificates.

The certificate verification options -verify_hostname, -verify_ip, and -verify_email have no effect on the certificate verification enabled via this option.

-tls_hostname

Address to be checked during hostname validation. This may be a DNS name or an IP address. If not given it defaults to the -server address.

Client-side options for debugging and offline scenarios#

-batch

Do not interactively prompt for input, for instance when a password is needed. This can be useful for batch processing and testing.

-repeatnumber

Invoke the command the given positive number of times with the same parameters. Default is one invocation.

-reqinfilenames

This option is useful for supporting offline scenarios where the certificate request (or any other CMP request) is produced beforehand and sent out later.

This option is ignored if the -rspin option is given because in the latter case no requests are actually sent.

Note that in any case the client produces internally its sequence of CMP request messages. Thus, all options required for doing this (such as -cmd and all options providing the required parameters) need to be given also when the -reqin option is present.

If the -reqin option is given for a certificate request and no -newkey, -key, -oldcert, or -csr option is given, a fallback public key is taken from the request message file (if it is included in the certificate template).

Hint: In case the -reqin option is given for a certificate request, there are situations where the client has access to the public key to be certified but not to the private key that by default will be needed for proof of possession. In this case the POPO is not actually needed (because the internally produced certificate request message will not be sent), and its generation can be disabled using the options -popo-1 or -popo0.

Multiple filenames may be given, separated by commas and/or whitespace (where in the latter case the whole argument must be enclosed in "...").

The files are read as far as needed to complete the transaction and filenames have been provided. If more requests are needed, the remaining ones are taken from the items at the respective position in the sequence of requests produced internally.

The client needs to update the recipNonce field in the given requests (except for the first one) in order to satisfy the checks to be performed by the server. This causes re-protection (if protecting requests is required).

-reqin_new_tid

Use a fresh transactionID for CMP request messages read using -reqin, which causes their reprotection (if protecting requests is required). This may be needed in case the sequence of requests is reused and the CMP server complains that the transaction ID has already been used.

-reqoutfilenames

Multiple filenames may be given, separated by commas and/or whitespace.

Files are written as far as needed to save the transaction and filenames have been provided. If the transaction contains more requests, the remaining ones are not saved.

-reqout_onlyfilename

This option is useful for supporting offline scenarios where the certificate request (or any other CMP request) is produced beforehand and sent out later.

-rspinfilenames

Multiple filenames may be given, separated by commas and/or whitespace.

Any server specified via the -server or -use_mock_srv options is contacted only if more responses are needed to complete the transaction. In this case the transaction will fail unless the server has been prepared to continue the already started transaction.

-rspoutfilenames

Multiple filenames may be given, separated by commas and/or whitespace.

Files are written as far as needed to save the responses contained in the transaction and filenames have been provided. If the transaction contains more responses, the remaining ones are not saved.

-use_mock_srv

Test the client using the internal CMP server mock-up at API level, bypassing socket-based transfer via HTTP. This excludes the -server and -port options.

Mock server options#

-portnumber

Act as HTTP-based CMP server mock-up listening on the given local port. The client may address the server via, e.g., 127.0.0.1 or "[::1]". This option excludes the -server and -use_mock_srv options. The -rspin, -rspout, -reqin, and -reqout options so far are not supported in this mode.

-max_msgsnumber

Maximum number of CMP (request) messages the CMP HTTP server mock-up should handle, which must be nonnegative. The default value is 0, which means that no limit is imposed. In any case the server terminates on internal errors, but not when it detects a CMP-level error that it can successfully answer with an error message.

-srv_refvalue

Reference value to use as senderKID of server in case no -srv_cert is given.

-srv_secretarg

Password source for server authentication with a pre-shared key (secret).

-srv_certfilename|uri

Certificate of the server.

-srv_keyfilename|uri

Private key used by the server for signing messages.

-srv_keypassarg

Server private key (and cert) file pass phrase source.

-srv_trustedfilenames|uris

The certificate verification options -verify_hostname, -verify_ip, and -verify_email have no effect on the certificate verification enabled via this option.

-srv_untrustedfilenames|uris

Intermediate CA certs that may be useful when validating client certificates.

-ref_certfilename|uri

Certificate to be expected for RR messages and any oldCertID in KUR messages.

-rsp_certfilename|uri

Certificate to be returned as mock enrollment result.

-rsp_keyfilename|uri

Private key to be returned as central key generation result.

-rsp_keypassarg

Pass phrase source for rsp_cert and rsp_key.

-rsp_crlfilename|uri

CRL to be returned in genp of type "crls".

-rsp_extracertsfilenames|uris

Extra certificates to be included in mock certification responses.

-rsp_capubsfilenames|uris

CA certificates to be included in mock Initialization Response (IP) message.

-rsp_newwithnewfilename|uri

Certificate to be returned in newWithNew field of genp of type rootCaKeyUpdate.

-rsp_newwitholdfilename|uri

Certificate to be returned in newWithOld field of genp of type rootCaKeyUpdate.

-rsp_oldwithnewfilename|uri

Certificate to be returned in oldWithNew field of genp of type rootCaKeyUpdate.

-poll_countnumber

Number of times the client must poll before receiving a certificate.

-check_afternumber

The checkAfter value (number of seconds to wait) to include in poll response.

-grant_implicitconf

Grant implicit confirmation of newly enrolled certificate.

-pkistatusnumber

PKIStatus to be included in server response. Valid range is 0 (accepted) .. 6 (keyUpdateWarning).

-failurenumber

A single failure info bit number to be included in server response. Valid range is 0 (badAlg) .. 26 (duplicateCertReq).

-failurebitsnumber Number representing failure bits to be included in server response. Valid range is 0 .. 2^27 - 1.

-statusstringarg

Text to be included as status string in server response.

-send_error

Force server to reply with error message.

-send_unprotected

Send response messages without CMP-level protection.

-send_unprot_err

In case of negative responses, server shall send unprotected error messages, certificate responses (IP/CP/KUP), and revocation responses (RP). WARNING: This setting leads to behavior violating RFC 9810.

-accept_unprotected

Accept missing or invalid protection of requests.

-accept_unprot_err

Accept unprotected error messages from client. So far this has no effect because the server does not accept any error messages.

-accept_raverified

Accept RAVERIFIED as proof of possession (POPO).

Certificate verification options, for both CMP and TLS#

-allow_proxy_certs, -attime, -no_check_time, -check_ss_sig, -crl_check, -crl_check_all, -explicit_policy, -extended_crl, -ignore_critical, -inhibit_any, -inhibit_map, -no_alt_chains, -partial_chain, -policy, -policy_check, -policy_print, -purpose, -suiteB_128, -suiteB_128_only, -suiteB_192, -trusted_first, -use_deltas, -auth_level, -verify_depth, -verify_email, -verify_hostname, -verify_ip, -verify_name, -x509_strict-issuer_checks

The certificate verification options -verify_hostname, -verify_ip, and -verify_email only affect the certificate verification enabled via the -out_trusted option.

NOTES#

When a client obtains, from a CMP server, CA certificates that it is going to trust, for instance via the "caPubs" field of a certificate response or using general messages with infoType "caCerts" or "rootCaCert", authentication of the CMP server is particularly critical. So special care must be taken setting up server authentication using -trusted and related options for certificate-based authentication or -secret for MAC-based protection. If authentication is certificate-based, the -srvcertout option should be used to obtain the validated server certificate and perform an authorization check based on it.

When setting up CMP configurations and experimenting with enrollment options typically various errors occur until the configuration is correct and complete. When the CMP server reports an error the client will by default check the protection of the CMP response message. Yet some CMP services tend not to protect negative responses. In this case the client will reject them, and thus their contents are not shown although they usually contain hints that would be helpful for diagnostics. For assisting in such cases the CMP client offers a workaround via the -unprotected_errors option, which allows accepting such negative messages.

If OpenSSL was built with trace support enabled (e.g., "./config enable-trace") and the environment variable OPENSSL_TRACE includes HTTP, the requests and the response headers transferred via HTTP are printed.

EXAMPLES#

Simple examples using the default OpenSSL configuration file#

This CMP client implementation comes with demonstrative CMP sections in the example configuration file openssl/apps/openssl.cnf, which can be used to interact conveniently with the Insta Demo CA.

In order to enroll an initial certificate from that CA it is sufficient to issue the following shell commands.

  export OPENSSL_CONF=/path/to/openssl/apps/openssl.cnf

  openssl genrsa -out insta.priv.pem
  openssl cmp -section insta

This should produce the file insta.cert.pem containing a new certificate for the private key held in insta.priv.pem. It can be viewed using, e.g.,

  openssl x509 -noout -text -in insta.cert.pem

In case the network setup requires using an HTTP proxy it may be given as usual via the environment variable http_proxy or via the -proxy option in the configuration file or the CMP command-line argument -proxy, for example

  -proxy http://192.168.1.1:8080

In the Insta Demo CA scenario both clients and the server may use the pre-shared secret insta and the reference value 3078 to authenticate to each other.

Alternatively, CMP messages may be protected in signature-based manner, where the trust anchor in this case is insta.ca.crt and the client may use any certificate already obtained from that CA, as specified in the [signature] section of the example configuration. This can be used in combination with the [insta] section simply by

  openssl cmp -section insta,signature

By default the CMP IR message type is used, yet CR works equally here. This may be specified directly at the command line:

  openssl cmp -section insta -cmd cr

or by referencing in addition the [cr] section of the example configuration:

  openssl cmp -section insta,cr

In order to update the enrolled certificate one may call

  openssl cmp -section insta,kur,signature

using signature-based protection with the certificate that is to be updated. For certificate updates, MAC-based protection should generally not be used.

In a similar way any previously enrolled certificate may be revoked by

  openssl cmp -section insta,rr -trusted insta.ca.crt

or

  openssl cmp -section insta,rr,signature

Many more options can be given in the configuration file and/or on the command line. For instance, the -reqexts CLI option may refer to a section in the configuration file defining X.509 extensions to use in certificate requests, such as "v3_req" in openssl/apps/openssl.cnf:

  openssl cmp -section insta,cr -reqexts v3_req

Certificate enrollment#

The following examples do not make use of a configuration file at first. They assume that a CMP server can be contacted on the local TCP port 80 and accepts requests under the alias /pkix/.

For enrolling its very first certificate the client generates a client key and sends an initial request message to the local CMP server using a pre-shared secret key for mutual authentication. In this example the client does not have the CA certificate yet, so we specify the name of the CA with the -recipient option and save any CA certificates that we may receive in the "capubs.pem" file.

In below command line usage examples the "\" at line ends is used just for formatting; each of the command invocations should be on a single line.

  openssl genrsa -out cl_key.pem
  openssl cmp -cmd ir -server 127.0.0.1:80/pkix/ -recipient "/CN=CMPserver" \
    -ref 1234 -secret pass:1234-5678 \
    -newkey cl_key.pem -subject "/CN=MyName" \
    -cacertsout capubs.pem -certout cl_cert.pem

Certificate update#

Then, when the client certificate and its related key pair needs to be updated, the client can send a key update request taking the certs in "capubs.pem" as trusted for authenticating the server and using the previous cert and key for its own authentication. Then it can start using the new cert and key.

  openssl genrsa -out cl_key_new.pem
  openssl cmp -cmd kur -server 127.0.0.1:80/pkix/ \
    -trusted capubs.pem \
    -cert cl_cert.pem -key cl_key.pem \
    -newkey cl_key_new.pem -certout cl_cert.pem
  cp cl_key_new.pem cl_key.pem

This command sequence can be repeated as often as needed.

Requesting information from CMP server#

Requesting "all relevant information" with an empty General Message. This prints information about all received ITAV infoTypes to stdout.

  openssl cmp -cmd genm -server 127.0.0.1/pkix/ -recipient "/CN=CMPserver" \
    -ref 1234 -secret pass:1234-5678

Using a custom configuration file#

For CMP client invocations, in particular for certificate enrollment, usually many parameters need to be set, which is tedious and error-prone to do on the command line. Therefore, the client offers the possibility to read options from sections of the OpenSSL config file, usually called openssl.cnf. The values found there can still be extended and even overridden by any subsequently loaded sections and on the command line.

After including in the configuration file the following sections:

  [cmp]
  server = 127.0.0.1
  path = pkix/
  trusted = capubs.pem
  cert = cl_cert.pem
  key = cl_key.pem
  newkey = cl_key.pem
  certout = cl_cert.pem
  [init]
  recipient = "/CN=CMPserver"
  trusted =
  cert =
  key =
  ref = 1234
  secret = pass:1234-5678-1234-567
  subject = "/CN=MyName"
  cacertsout = capubs.pem

the above enrollment transactions reduce to

  openssl cmp -section cmp,init
  openssl cmp -cmd kur -newkey cl_key_new.pem

and the above transaction using a general message reduces to

  openssl cmp -section cmp,init -cmd genm

SEE ALSO#

openssl-genrsa(1), openssl-ecparam(1), openssl-list(1), openssl-req(1), openssl-x509(1), x509v3_config(5)

HISTORY#

The cmp application was added in OpenSSL 3.0.

The -engine option was deprecated in OpenSSL 3.0.

The -oldwithold, -newwithnew, -newwithold, -oldwithnew, The -srvcertout, and -serial option were added in OpenSSL 3.2, as well as an extension of -cacertsout to use when getting CA certificates. Since then, the -issuer may be used also for certificates to be revoked.

The -profile and -no_cache_extracerts options were added in OpenSSL 3.3, as well as support for delayed delivery of all types of response messages.

The -template, -crlcert, -oldcrl, -crlout, -crlform and -rsp_crl options were added in OpenSSL 3.4.

-centralkeygen, b<-newkeyout>, -rsp_key and -rsp_keypass were added in OpenSSL 3.5.

COPYRIGHT#

Copyright 2007-2025 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>.