CMCRequest - Man Page

Used to generate a CMC certificate issuance or revocation request.


CMCRequest config-file


The Certificate Management over Cryptographic Message Syntax (CMC) Request Generation utility, CMCRequest, provides a command-line utility used to generate a CMC certificate issuance or revocation request. For issuance request, it requires either a PKCS#10 or CRMF request as input. The resulting CMC request can be sent to the CA via tool such as HttpClient.

CMCRequest takes a configuration file where various configuration parameters are supported.

Configuration Parameters

The following are supported configuration parameters for the configuration file. Each parameter is in the format of <name>=<value> (e.g. format=pkcs10).


Total number of PKCS10 or CRMF requests. (note: lately the CA has only been tested to work with one)


Full path for PKCS #10 or CRMF certificate request in PEM.

For example if PKCS10Client or CRMFPopClient are used to generate the PKCS#10 or CRMF requests respectively, this value should be the value of the -o option of those command line tools.


Request format. Either pkcs10 or crmf.


Full path for the resulting CMC request in ASN.1 DER encoded format.

Note that this would be the input in the HttpClient configuration file if it is used to submit the CMC request.


Directory for NSS database.


Name of crypto token where user signing certificate key can be found (default is internal).


The nickname of the user certificate that corresponds to the private key that is used to sign the request.

This parameter is ignored if useSharedSecret or identityProofV2.enable is true.


Password to the crypto token where the signing user's certificate and keys are stored.


RFC 5272 allows the CA to require inclusion of the identification control to accompany the identityProofV2 control in a CMC request.

In PKI, CA employs the identification control to assist in locating the shared secret required for verification of the shared secret computed in the identityProofV2.

In addition, the identification control is also required for popLinkWitnessV2 for locating the shared secret.

When identification.enable is true, identification should contain a user id known by the CA.


The witness.sharedSecret should contain a passphrase that is known by the CA. One usually obtains it from the CA administrator.

This parameter is required by the following options: identityProofV2, and popLinkWitnessV2.

See CMCSharedToken(1) for information on usage.

identityProofV2.[enable, hashAlg, macAlg]

Identity Proof V2 allows one to provide proof of identity without a signing certificate. It does so by embedding a "witness" value that's calculated from a shared secret (see witness.sharedSecret) known by the CA.

The identityProofV2 parameter set allows a user to specify the hashing algorithm as well as MAC (Message Authentication Code) algorithm used to compute the value of the witness value.

Supported identityProofV2.hashAlg are: SHA-256, SHA-384, and SHA-512.

Supported identityProofV2.macAlg are: SHA-256-HMAC, SHA-384-HMAC, and SHA-512-HMAC.

When identityProofV2.enable is true, these parameters must be accompanied by the identification as well as the witness.sharedSecret parameters.

These parameters could be accompanied by the popLinkWitnessV2 parameter set if required by the CA.

popLinkWitnessV2.[enable, keyGenAlg, macAlg]

The POPLinkWitnessV2 control is a mechanim that links the POP (Proof of Possession) to the identity, which adds more credibility to the otherwise distinct POP and Proof of Identity mechanisms. It does so by employing calculation of a random value with a shared secret (see witness.sharedSecret) known by the CA.

The POP Link Witness V2 value must be baked into the PKCS#10 or CRMF requests. It is therefore crutial that the caller that employs this option has access to the private key of the certificate request.

If popLinkWitnessV2 is used, then identification and witness.sharedSecret must be supplied, and the identityProofV2 parameter set is in general used.

Supported keyGenAlg are: SHA-256, SHA-384, and SHA-512.

Supported macAlg are: SHA-256-HMAC, SHA-384-HMAC, and SHA-512-HMAC.


true or false. If useSharedSecret is true, the CMC request will be "signed" with the pairing private key of the enrollment request; and in which case the nickname parameter will be ignored.

request.useSharedSecret is only used if a signing certificate (of the agent or user herself) is not available to sign. Because the request itself is not signed with a certificate (a proven identity), the proof of origin (proof of identification) must be provided by some other means.

In PKI, if request.useSharedSecret is true, it must be used in conjunction with the identityProofV2 and identification parameters. And in that case the Proof Of Origin is accomplished by the Shared Secret (witness.sharedSecret) mechanism.

The request.useSharedSecret option is normally used to enroll for a user's first signing certificate while auto-approval (without agent's pre-approval) is preferred. In general, once a user has obtained the first signing certificate, such signing certificate can be used to sign (thus proving origin) and obtain other certificate such as encryption-only ceritifcate, or when doing a renewal or revocation.

By default, if unspecified, request.useSharedSecret is false.

Note: to employ the request.useSharedSecret option, the PKCS#10 or CRMF requests must have the SubjectKeyIdentifier extension. (hint: CRMFPopClient and PKCS10Client should be called with the "-y" option)

If request.useSharedSecret is true, request.privKeyId must be specified. It is crucial that the caller that employs this option has access to the private key of the certificate request.


The request.privKeyId parameter is required in the following cases: request.useSharedSecret, popLinkWitnessV2, and decryptedPop

decryptedPop.enable, encryptedPopResponseFile, decryptedPopRequestFile

In case when the enrolling key is an encryption-only key, the traditional POP (Proof of Possession) that employs signing of the request is not possible, CMC provides the EncryptedPOP/DecryptedPOP  mechanism to allow the CA to challenge the client. This mechanism requires two trips. First trip (a CMC request without POP) would trigger the CA to generate a challenge and encrypt the challenge with the request public key in the certificate response (one should find the EncryptedPOP control as well as status with "failedInfo=POP required" in the CMCResponse); while second trip from the client would contain proof that the client has decrypted the challenge and thereby proving ownership of the private key to the enrollment request. When preparing for the second trip, the following parameters must be present:

decryptedPop.enable - set to true; default is false;

encryptedPopResponseFile - The input file that contains the CMCResponse from first trip; It should contains the CMC EncryptedPop control.

decryptedPopRequestFile - The output file for the CMC request which should contain the CMC DecryptedPOP control.

request.privKeyId - see descripton for request.privKeyId; It is used to decrypt the EncryptedPop, thereby proving the possession of the private key.

Please note that the PopLinkWitnessV2 control as well as the request.useSharedSecret directive do not apply to EncryptedPOP/DecryptedPOP for the simple fact that the enrollment private key is not capable of signing.

revRequest.[enable, serial, reason, comment, issuer, sharedSecret]

Revocation can be done either by signing with user's own valid signing certificate, or by authenticating with user's shared secret (see witness.sharedSecret) known by the CA.

For revocation request signed with user's own valid signing certificate, the nickname parameter should be a valid user signing certificate that belongs to the same user subject as that of the certificate to be revoked (but not necessarily the same certificate); Also, revRequest.issuer and revRequest.sharedSecret are ignored, while revRequest.serial and revRequest.reason must contain valid values.

For revocation by authenticating with user's shared secret, the following parameters are required: revRequest.serial, revRequest.reason, revRequest.issuer, revRequest.sharedSecret, while nickname will be ignored.

revRequest.reason  can have one of the following values: unspecified, keyCompromise, caCompromise, affiliationChanged, superseded, cessationOfOperation, certificateHold, removeFromCRL.

revRequest.serial is in Decimal.

revRequest.issuer is issuer subject DN.

revRequest.invalidityDatePresent is optional. true or false. When true, the invalidityDate of the RevokeRequest will be set to the current time when this tool is being run.

revRequest.comment is optional.


CMC requests must be submitted to the CA to be processed. Tool supported by PKI for submitting these requests is HttpClient.

Note: For examples on how to use this tool, please see Practical Usage Scenarios ⟨⟩#Practical_Usage_Scenarios), and their examples.

See Also

CMCResponse(1), CMCSharedToken(1), CMCRevoke(1), pki(1)


Christina Fu <>.

Referenced By

CMCEnroll(1), CMCResponse(1), CMCSharedToken(1).

March 14, 2018 PKI CMC Request Generation Tool