5.6. Submitting Certificate requests Using CMC

This section describes the procedure to enroll a certificate using Certificate Management over CMS (CMC).

For general information about configuration and the workflow of enrolling certificates using CMC, see:

The Configuration for CMC section in the Red Hat Certificate System Planning, Installation, and Deployment Guide.
The Enrolling with CMC section in the Red Hat Certificate System Planning, Installation, and Deployment Guide.
CMCRequest(1) man page
CMCResponse(1) man page

CMC enrollment is possible in various ways to meet the requirements for different scenarios. Section 5.6.2, “The CMC Enrollment Process” supplements the Enrolling with CMC section in the Red Hat Certificate System Planning, Installation, and Deployment Guide with more details. Additionally, the Section 5.6.3, “Practical CMC Enrollment Scenarios” section enables administrators to decide which mechanisms should be used in which scenario.

5.6.1. Using CMC Enrollment

CMC enrollment allows an enrollment client to use a CMCAuth plug-in for authentication, by which the certificate request is pre-signed with an agent certificate. The Certificate Manager automatically issues certificates when a valid request signed with the agent certificate is received.

Note

CMC enrollments are enabled by default. It should not be necessary to enable the CMC enrollment authentication plug-ins or profiles unless the configuration has been changed.

The CMCAuth authentication plug-in also provides CMC revocation for the client. CMC revocation allows the client to have the certificate request signed by the agent certificate, and then send such a request to the Certificate Manager. The Certificate Manager automatically revokes certificates when a valid request signed with the agent certificate is received. CMC revocation can be created with the CMCRevoke command line tool. For more information about CMCRevoke, see Section 7.2, “Performing a CMC Revocation”.

A CMC request can be submitted through browser end-entities forms or using a tool such as HttpClient to post the request to the appropriate profile. The CMCRequest tool generates a signed certificate request which can then be submitted using the HttpClient tool or the browser end-entities forms to enroll and receive the certificate automatically and immediately.

The CMCRequest tool has a simple command syntax, with all the configuration given in the .cfg input file:

CMCRequest /path/to/file.cfg

A single CMC enrollment can also be created using the CMCEnroll tool, with the following syntax:

CMCEnroll -d /agent's/certificate/directory -h password -n cert_nickname -r certrequest.file -p certDB_passwd [-c "comment"]

These tools are described in more detail in the CMCEnroll(1) man page.

Note

Surround values that include spaces in quotation marks.

5.6.1.1. Testing CMCEnroll

Create a certificate request using the certutil tool.
Copy the PKCS #10 ASCII output to a text file.
Run the CMCEnroll utility.
For example, if the input file called request34.txt, the agent certificate is stored in the browser databases, the certificate common name of the agent certificate is CertificateManagerAgentsCert, and the password for the certificate database is secret, the command is as follows:
```
CMCEnroll -d ~jsmith/.mozilla/firefox/1234.jsmith -n "CertificateManagerAgentsCert" -r /export/requests/request34.txt -p secret
```
The output of this command is stored in a file with the same filename with .out appended to the filename.
Submit the signed certificate through the end-entities page.
1. Open the end-entities page.
```
https://server.example.com:8443/ca/ee/ca
```
2. Select the CMC enrollment form from the list of certificate profiles.
3. Paste the content of the output file into the Certificate Request text area of this form.
4. Remove -----BEGIN NEW CERTIFICATE REQUEST----- and ----END NEW CERTIFICATE REQUEST----- from the pasted content.
5. Fill in the contact information, and submit the form.
The certificate is immediately processed and returned.
Use the agent page to search for the new certificate.

5.6.2. The CMC Enrollment Process

Use the following general procedure to request and issue a certificate using CMC:

Create a Certificate Signing Request (CSR) in one of the following formats:
- PKCS #10 format
- Certificate Request Message Format (CRMF) format
For details about creating CSRs in these formats, see Section 5.2, “Creating Certificate Signing Requests”.
Import the admin certificate into the client NSS database. For example:
- Execute the command below to extract the admin client certificate from the .p12 file:
```
$ openssl pkcs12 -in /root/.dogtag/instance/ca_admin_cert.p12 -clcerts -nodes -nokeys -out /root/.dogtag/instance/ca_admin_cert.crt
```
- Validate and import the admin client certificate according to guidance in Managing Certificate/Key Crypto Token section in the Red Hat Certificate System Planning, Installation, and Deployment Guide:
```
$ PKICertImport -d . -n "CA Admin - Client Certificate" -t ",," -a -i /root/.dogtag/instance/ca_admin_cert.crt -u C
```
  Important
  Make sure all intermediate certificates and the root CA certificate have been imported before importing the CA Admin client certificate.
- Import the private keys associated with the certificates.
```
$ pki -c password pkcs12-import --pkcs12-file /root/.dogtag/instance/ca_admin_cert.p12 --pkcs12-password-file /root/.dogtag/instance/ca/pkcs12_password.conf
```

Create a configuration file for a CMC request, such as /home/user_name/cmc-request.cfg, with the following content:

# NSS database directory where CA agent certificate is stored
dbdir=/home/user_name/.dogtag/nssdb/

# NSS database password
password=password

# Token name (default is internal)
tokenname=internal

# Nickname for signing certificate
nickname=subsystem_admin

# Request format: pkcs10 or crmf
format=pkcs10

# Total number of PKCS10/CRMF requests
numRequests=1

# Path to the PKCS10/CRMF request
# The content must be in Base-64 encoded format.
# Multiple files are supported. They must be separated by space.
input=/home/user_name/file.csr

# Path for the CMC request
output=/home/user_name/cmc-request.bin

For further details, see the CMCRequest(1) man page.

Create the CMC request:
```
$ CMCRequest /home/user_name/cmc-request.cfg
```
If the command succeeds, the CMCRequest utility stored the CMC request in the file specified in the output parameter in the request configuration file.

Create a configuration file for HttpClient, such as /home/user_name/cmc-submit.cfg, which you use in a later step to submit the CMC request to the CA. Add the following content to the created file:

# PKI server host name
host=server.example.com

# PKI server port number
port=8443

# Use secure connection
secure=true

# Use client authentication
clientmode=true

# NSS database directory where the CA agent certificate is stored.
dbdir=/home/user_name/.dogtag/nssdb/

# NSS database password
password=password

# Token name (default: internal)
tokenname=internal

# Nickname of signing certificate
nickname=subsystem_admin

# Path for the CMC request
input=/home/user_name/cmc-request.bin

# Path for the CMC response
output=/home/user_name/cmc-response.bin

Important

The nickname of the certificate specified in the nickname parameter must match the one previously used for the CMC request.

Depending on what type of certificate you request, add the following parameter to the configuration file created in the previous step:
```
servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=profile_name
```
For example, for a CA signing certificate:
```
servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCcaCert
```
Important
When an agent submits the CMC request in the next step, the profile specified in this parameter must use the CMCAuth authentication plug-in. Whereas in user-initiated enrollments, the profile must use the CMCUserSignedAuth plug-in. For further details, see the Section 9.3, “CMC Authentication Plug-ins”.

Submit the CMC request to the CA:

$ HttpClient /home/user_name/cmc-submit.cfg

To convert the CMC response to a PKCS #7 certificate chain, pass the CMC response file to the -i parameter of the CMCResponse utility. For example:
```
$ CMCResponse -i /home/user_name/cmc-response.bin -o /home/user_name/cert_chain.crt
```

5.6.3. Practical CMC Enrollment Scenarios

This section describes frequent practical usage scenarios and their workflows to enable CA administrators to decide which CMC method to use in which situation.

For a general process of enrolling a certificate using CMC, see Section 5.6.2, “The CMC Enrollment Process”.

5.6.3.1. Obtaining System and Server Certificates

If a service, such as LDAP or a web server, requires a TLS server certificate, the administrator of this server creates a CSR based on the documentation of the service and sends it to the CA's agent for approval. Use the procedure described in Section 5.6.2, “The CMC Enrollment Process” for this process. Additionally, consider the following requirements:

Enrollment Profiles

The agent must either use one of the existing CMC profiles listed in Section 9.3, “CMC Authentication Plug-ins”, or, alternatively, create a custom profile that uses the CMCAuth authentication mechanism.

CMC Signing Certificate

For system certificates, the CA agent must generate and sign the CMC request. For this, set the nickname parameter in the CMCRequest configuration file to the nickname of the CA agent.

Note

The CA agent must have access to its own private key.

HttpClient TLS Client Nickname

Use the same certificate for signing in the CMCRequest utility's configuration file as for TLS client authentication in the configuration file for HttpClient.

HttpClient servlet Parameter

The servlet in the configuration file passed to the HttpClient utility refers to the CMC servlet and the enrollment profile which handles the request.

Depending on what type of certificate you request, add one of the following entries to the configuration file created in the previous step:

For a CA signing certificate:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCcaCert

For a KRA transport certificate:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCkraTransportCert

For a OCSP signing certificate:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCocspCert

For a audit signing certificate:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCauditSigningCert

For a subsystem certificate:

For RSA certificates:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCsubsystemCert

For ECC certificates:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCECCsubsystemCert

For a TLS server certificate:

For RSA certificates:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCserverCert

For ECC certificates:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caCMCECCserverCert

For an admin certificate:

servlet=/ca/ee/ca/profileSubmitCMCFull?profileId=caFullCMCUserCert

Further details:

When an agent pre-signs a CSR, the Proof of Identification is considered established because the agent examines the CSR for identification. No additional CMC-specific identification proof is required.
PKCS #10 files already provide Proof of Possession information and no additional Proof of Possession (POP) is required.
In agent pre-approved requests, the PopLinkWittnessV2 feature must be disabled because the identification is checked by the agent.

5.6.3.2. Obtaining the First Signing Certificate for a User

There are two ways to approve a user's first signing certificate:

An agent signs the CMC request. See Section 5.6.3.2.1, “Signing a CMC Request with an Agent Certificate”.
Certificate enrollment is authenticated by using a Shared Secret. See Section 5.6.3.2.2, “Authenticating for Certificate Enrollment Using a Shared Secret”.

5.6.3.2.1. Signing a CMC Request with an Agent Certificate

The process for signing a CMC request with an agent certificate is the same as for system and server certificates described in Section 5.6.3.1, “Obtaining System and Server Certificates”. The only difference is that the user creates the CSR and sends it to a CA agent for approval.

5.6.3.2.2. Authenticating for Certificate Enrollment Using a Shared Secret

When a user wants to obtain the first signing certificate and the agent cannot approve the request as described in Section 5.6.3.2.1, “Signing a CMC Request with an Agent Certificate”, you can use a Shared Token. With this token, the user can obtain the first signing certificate. This certificate can then be used to sign other certificates of the user.

In this scenario, use the Shared Secret mechanism to obtain the first signing certificate of the user. Use the following information together with Section 5.6.2, “The CMC Enrollment Process”:

Create a Shared Token either as the user or CA administrator. For details, see Section 9.4.1, “Creating a Shared Secret Token”.
Note that:
- If the user created the token, the user must send the token to the CA administrator.
- If the CA administrator created the token, the administrator must share the password used to generate the token with the user. Use a secure way to transmit the password.
As the CA administrator, add the Shared Token to the user entry in LDAP. For details, see Section 9.4.2.1, “Adding a CMC Shared Secret to a User Entry for Certificate Enrollment” and the Enabling the CMC Shared Secret Feature section in the Red Hat Certificate System Planning, Installation, and Deployment Guide.
Use the following parameters in the configuration file passed to the CMCRequest utility:
- identification.enable
- witness.sharedSecret
- identityProofV2.enable
- identityProofV2.hashAlg
- identityProofV2.macAlg
- request.useSharedSecret
- request.privKeyId
If required by the CA, additionally use the following parameters in the configuration file passed to the CMCRequest utility:
- popLinkWitnessV2.enable
- popLinkWitnessV2.keyGenAlg
- popLinkWitnessV2.macAlg

5.6.3.3. Obtaining an Encryption-only Certificate for a User

This section describes the workflow for obtaining an encryption-only certificate which is signed with an existing user signing certificate:

Note

If a user owns multiple certificates for different usages, where one is signing, the user must obtain the signing certificate first. Once the user owns a signing certificate, it can be used for Proof Of Origin without requiring to set up and rely on the CMC Shared Secret mechanism.

For details about obtaining a user's first signing certificate, see Section 5.6.3.2, “Obtaining the First Signing Certificate for a User”.

As a user:

Use the cryptographic token stored in a Network Security Services (NSS) database or on a smart card that contains the user's signing certificate and keys.
Generate the CSR in PKCS #10 or the CRMF format.
Note
Use the CRMF format, if key archival is required.
Generate the CMC request.
Since this is an encryption-only certificate, the private key is not able to sign. Therefore, Proof Of Possession (POP) is not included. For this reason, the enrollment requires two steps: If the initial request is successful, results in a CMC status with the EncryptedPOP control. The user then uses the response and generates a CMC request that contains the DecryptedPOP control and submits it in the second step.
1. For the first step, in addition to the default parameters, the user must set the following parameters in the configuration file passed to the CMCRequest utility:
  - identification.enable
  - witness.sharedSecret
  - identityProofV2.enable
  - identityProofV2.hashAlg
  - identityProofV2.macAlg
  - popLinkWitnessV2.enable if required by the CA
  - popLinkWitnessV2.keyGenAlg if required by the CA
  - popLinkWitnessV2.macAlg if required by the CA
  - request.privKeyId
  For details, see the CMCRequest(1) man page.
  The response contains:
  - A CMC encrypted POP control
  - The CMCStatusInfoV2 control with the POP required error
  - The request ID
2. For the second step, in addition to the default parameters, the user must set the following parameters in the configuration file passed to the CMCRequest utility:
  - decryptedPop.enable
  - encryptedPopResponseFile
  - decryptedPopRequestFile
  - request.privKeyId
  For details, see the CMCRequest(1) man page.

5.6.3.3.1. Example on Obtaining an Encryption-only certificate with Key Archival

To perform an enrollment with key archival, generate a CMC request that contains the user's encrypted private key in the CRMF request. The following procedure assumes that the user already owns a signing certificate. The nickname of this signing certificate is set in the configuration files in the procedure.

Note

The following procedure describes the two-trip issuance used with encryption-only keys, which cannot be used for signing. If you use a key which can sign certificates, pass the -q POP_SUCCESS option instead of -q POP_NONE to the CRMFPopClient utility for a single-trip issuance.

For instructions about using CRMFPoPClient with POP_SUCCESS, see Section 5.2.1.3.1, “Using CRMFPopClient to Create a CSR with Key Archival” and Section 5.2.1.3.2, “Using CRMFPopClient to Create a CSR for SharedSecret-based CMC”.

Search for the KRA transport certificate. For example:

$ pki cert-find --name KRA_transport_certificate_subject_CN

Use the serial number of the KRA transport certificate, which you retrieved in the previous step, to store the certificate in a file. For example, to store the certificate with the 12345 serial number in the /home/user_name/kra.cert file:
```
$ pki cert-show 12345 --output /home/user_name/kra.cert
```
Use the CRMFPopClient utility to:
- Create a CSR with key archival:
  1. Change to the certificate database directory of the user or entity for which the certificate is being requested, for example:
    $ cd /home/user_name/
  2. Use the CRMFPopClient utility to create a CRMF request, where the RSA private key is wrapped by the KRA transport certificate. For example, to store the request in the /home/user_name/crmf.req file:
    $ CRMFPopClient -d . -p token_password -n subject_DN -q POP_NONE \ -b /home/user_name/kra.cert -w "AES/CBC/PKCS5Padding" \ -v -o /home/user_name/crmf.req
    Note the ID of the private key displayed by the command. The ID is required in a later step as value in the request.privKeyId parameter in the configuration file for the second trip.

Create a configuration file for the CRMRequest utility, such as /home/user_name/cmc.cfg with the following content:

#numRequests: Total number of PKCS10 requests or CRMF requests.
numRequests=1

#input: full path for the PKCS10 request or CRMF request,
#the content must be in Base-64 encoded format
input=/home/user_name/crmf.req

#output: full path for the CMC request in binary format
output=/home/user_name/cmc.req

#tokenname: name of token where agent signing cert can be found
#(default is internal)
tokenname=internal

#nickname: nickname for user certificate which will be used
#to sign the CMC full request.
nickname=signing_certificate

#dbdir: directory for cert8.db, key3.db and secmod.db
dbdir=/home/user_name/.dogtag/nssdb/

#password: password for cert8.db which stores the agent certificate
password=password

#format: request format, either pkcs10 or crmf
format=crmf

Create the CMC request:
```
$ CMCRequest /home/user_name/cmc.cfg
```
If the command succeeds, the CMCRequest utility stored the CMC request in the file specified in the output parameter in the request configuration file.

#host: host name for the http server
host=server.example.com

#port: port number
port=8443

#secure: true for secure connection, false for nonsecure connection
secure=true

#input: full path for the enrollment request, the content must be in
#binary format
input=/home/user_name/cmc.req

#output: full path for the response in binary format
output=/home/user_name/cmc-response_round_1.bin

#tokenname: name of token where TLS client authentication cert can be found
#(default is internal)
#This parameter will be ignored if secure=false
tokenname=internal

#dbdir: directory for cert8.db, key3.db and secmod.db
#This parameter will be ignored if secure=false
dbdir=/home/user_name/.dogtag/nssdb/

#clientmode: true for client authentication, false for no client authentication
#This parameter will be ignored if secure=false
clientmode=true

#password: password for cert8.db
#This parameter will be ignored if secure=false and clientauth=false
password=password

#nickname: nickname for client certificate
#This parameter will be ignored if clientmode=false
nickname=signing_certificate

#servlet: servlet name
servlet=/ca/ee/ca/profileSubmitUserSignedCMCFull?profileId=caFullCMCUserSignedCert

Submit the CMC request to the CA:
```
$ HttpClient /home/user_name/cmc-submit.cfg
```
If the command succeeds, the HTTPClient utility stored the CMC response in the file specified in the output parameter in the configuration file.

Verify the response by passing the response file to the CMCResponse utility. For example:

$ CMCResponse -d /home/user_name/.dogtag/nssdb/ -i /home/user_name/cmc-response_round_1.bin

If the first trip was successful, CMCResponse displays output similar to the following:

Certificates:
		Certificate:
				Data:
						Version:  v3
						Serial Number: 0x1
						Signature Algorithm: SHA256withRSA - 1.2.840.113549.1.1.11
						Issuer: CN=CA Signing Certificate,OU=pki-tomcat,O=unknown00262DFC6A5E Security Domain
						Validity:
								Not Before: Wednesday, May 17, 2017 6:06:50 PM PDT America/Los_Angeles
								Not  After: Sunday, May 17, 2037 6:06:50 PM PDT America/Los_Angeles
						Subject: CN=CA Signing Certificate,OU=pki-tomcat,O=unknown00262DFC6A5E Security Domain
...
Number of controls is 3
Control #0: CMC encrypted POP
	 OID: {1 3 6 1 5 5 7 7 9}
		 encryptedPOP decoded
Control #1: CMCStatusInfoV2
	 OID: {1 3 6 1 5 5 7 7 25}
	 BodyList: 1
	 OtherInfo type: FAIL
		 failInfo=POP required
Control #2: CMC ResponseInfo
	 requestID: 15

For the second trip, create a configuration file for DecryptedPOP, such as /home/user_name/cmc_DecryptedPOP.cfg, which you use in a later step. Add the following content to the created file:

#numRequests: Total number of PKCS10 requests or CRMF requests.
numRequests=1

#input: full path for the PKCS10 request or CRMF request,
#the content must be in Base-64 encoded format
#this field is actually unused in 2nd trip
input=/home/user_name/crmf.req

#output: full path for the CMC request in binary format
#this field is actually unused in 2nd trip
output=/home/user_name/cmc2.req

#tokenname: name of token where agent signing cert can be found
#(default is internal)
tokenname=internal

#nickname: nickname for agent certificate which will be used
#to sign the CMC full request.
nickname=signing_certificate

#dbdir: directory for cert8.db, key3.db and secmod.db
dbdir=/home/user_name/.dogtag/nssdb/

#password: password for cert8.db which stores the agent
#certificate
password=password

#format: request format, either pkcs10 or crmf
format=crmf

decryptedPop.enable=true
encryptedPopResponseFile=/home/user_name/cmc-response_round_1.bin
request.privKeyId=-25aa0a8aad395ebac7e6a19c364f0dcb5350cfef
decryptedPopRequestFile=/home/user_name/cmc.DecryptedPOP.req

Create the DecryptPOP CMC request:
```
$ CMCRequest /home/user_name/cmc.DecryptedPOP.cfg
```
If the command succeeds, the CMCRequest utility stored the CMC request in the file specified in the decryptedPopRequestFile parameter in the request configuration file.

Create a configuration file for HttpClient, such as /home/user_name/decrypted_POP_cmc-submit.cfg, which you use in a later step to submit the DecryptedPOP CMC request to the CA. Add the following content to the created file:

#host: host name for the http server
host=server.example.com

#port: port number
port=8443

#secure: true for secure connection, false for nonsecure connection
secure=true

#input: full path for the enrollment request, the content must be in binary format
input=/home/user_name/cmc.DecryptedPOP.req

#output: full path for the response in binary format
output=/home/user_name/cmc-response_round_2.bin

#tokenname: name of token where TLS client authentication cert can be found (default is internal)
#This parameter will be ignored if secure=false
tokenname=internal

#dbdir: directory for cert8.db, key3.db and secmod.db
#This parameter will be ignored if secure=false
dbdir=/home/user_name/.dogtag/nssdb/

#clientmode: true for client authentication, false for no client authentication
#This parameter will be ignored if secure=false
clientmode=true

#password: password for cert8.db
#This parameter will be ignored if secure=false and clientauth=false
password=password

#nickname: nickname for client certificate
#This parameter will be ignored if clientmode=false
nickname=singing_certificate

#servlet: servlet name
servlet=/ca/ee/ca/profileSubmitUserSignedCMCFull?profileId=caFullCMCUserCert

Submit the DecryptedPOP CMC request to the CA:
```
$ HttpClient /home/user_name/decrypted_POP_cmc-submit.cfg
```
If the command succeeds, the HTTPClient utility stored the CMC response in the file specified in the output parameter in the configuration file.

To convert the CMC response to a PKCS #7 certificate chain, pass the CMC response file to the -i parameter of the CMCResponse utility. For example:

$ CMCResponse -i /home/user_name/cmc-response_round_2.bin -o /home/user_name/certs.p7

Alternatively, to display the individual certificates in PEM format, pass the -v to the utility.

If the second trip was successful, CMCResponse displays output similar to the following:

Certificates:
		Certificate:
				Data:
						Version:  v3
						Serial Number: 0x2D
						Signature Algorithm: SHA256withRSA - 1.2.840.113549.1.1.11
						Issuer: CN=CA Signing Certificate,OU=pki-tomcat,O=unknown00262DFC6A5E Security Domain
						Validity:
								Not Before: Thursday, June 15, 2017 3:43:45 PM PDT America/Los_Angeles
								Not  After: Tuesday, December 12, 2017 3:43:45 PM PST America/Los_Angeles
						Subject: CN=user_name,UID=example,OU=keyArchivalExample
...
Number of controls is 1
Control #0: CMCStatusInfo
	 OID: {1 3 6 1 5 5 7 7 1}
	 BodyList: 1
	 Status: SUCCESS

5.6. Submitting Certificate requests Using CMC

5.6.1. Using CMC Enrollment

5.6.1.1. Testing CMCEnroll

5.6.2. The CMC Enrollment Process

5.6.3. Practical CMC Enrollment Scenarios

5.6.3.1. Obtaining System and Server Certificates

5.6.3.2. Obtaining the First Signing Certificate for a User

5.6.3.2.1. Signing a CMC Request with an Agent Certificate

5.6.3.2.2. Authenticating for Certificate Enrollment Using a Shared Secret

5.6.3.3. Obtaining an Encryption-only Certificate for a User

5.6.3.3.1. Example on Obtaining an Encryption-only certificate with Key Archival

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