4. Contents of a Set of Provisions
This section expands upon the contents of the simple framework of provisions, as introduced in Section 3.7. The topics identified in this section are, consequently, candidate topics for inclusion in a detailed CP or CPS.
While many topics are identified, it is not necessary for a CP or a CPS to include a concrete statement for every such topic. Rather, a particular CP or CPS may state "no stipulation" for a component, subcomponent, or element on which the particular CP or CPS imposes no requirements or makes no disclosure. In this sense, the list of topics can be considered a checklist of topics for consideration by the CP or CPS writer. It is recommended that each and every component and subcomponent be included in a CP or CPS, even if there is "no stipulation"; this will indicate to the reader that a conscious decision was made to include or exclude a provision concerning that topic. This drafting style protects against inadvertent omission of a topic, while facilitating comparison of different certificate policies or CPSs, e.g., when making policy mapping decisions. In a CP, it is possible to leave certain components, subcomponents, and/or elements unspecified, and to stipulate that the required information will be indicated in a policy qualifier, or the document to which a policy qualifier points. Such CPs can be considered parameterized definitions. The set of provisions should reference or define the required policy qualifier types and should specify any applicable default values.4.1. Introductions
This component identifies and introduces the set of provisions, and indicates the types of entities and applications for which the document (either the CP or the CPS being written) is targeted.4.1.1. Overview
This subcomponent provides a general introduction to the document being written. This subcomponent can also be used to provide a synopsis of the PKI to which the CP or CPS applies. For example, it may set out different levels of assurance provided by certificates within the PKI. Depending on the complexity and scope of the particular PKI, a diagrammatic representation of the PKI might be useful here.4.1.2. Document Name and Identification
This subcomponent provides any applicable names or other identifiers, including ASN.1 object identifiers, for the document. An example of such a document name would be the US Federal Government Policy for Secure E-mail.
4.1.3. PKI Participants
This subcomponent describes the identity or types of entities that fill the roles of participants within a PKI, namely: * Certification authorities, i.e., the entities that issue certificates. A CA is the issuing CA with respect to the certificates it issues and is the subject CA with respect to the CA certificate issued to it. CAs may be organized in a hierarchy in which an organization's CA issues certificates to CAs operated by subordinate organizations, such as a branch, division, or department within a larger organization. * Registration authorities, i.e., the entities that establish enrollment procedures for end-user certificate applicants, perform identification and authentication of certificate applicants, initiate or pass along revocation requests for certificates, and approve applications for renewal or re-keying certificates on behalf of a CA. Subordinate organizations within a larger organization can act as RAs for the CA serving the entire organization, but RAs may also be external to the CA. * Subscribers. Examples of subscribers who receive certificates from a CA include employees of an organization with its own CA, banking or brokerage customers, organizations hosting e-commerce sites, organizations participating in a business-to-business exchange, and members of the public receiving certificates from a CA issuing certificates to the public at large. * Relying parties. Examples of relying parties include employees of an organization having its own CA who receive digitally signed e- mails from other employees, persons buying goods and services from e-commerce sites, organizations participating in a business-to- business exchange who receive bids or orders from other participating organizations, and individuals and organizations doing business with subscribers who have received their certificates from a CA issuing certificates to the public. Relying parties may or may not also be subscribers within a given PKI. * Other participants, such as certificate manufacturing authorities, providers of repository services, and other entities providing PKI-related services.
4.1.4. Certificate Usage
This subcomponent contains: * A list or the types of applications for which the issued certificates are suitable, such as electronic mail, retail transactions, contracts, and a travel order, and/or * A list or the types of applications for which use of the issued certificates is prohibited. In the case of a CP or CPS describing different levels of assurance, this subcomponent can describe applications or types of applications that are appropriate or inappropriate for the different levels of assurance.4.1.5. Policy Administration
This subcomponent includes the name and mailing address of the organization that is responsible for the drafting, registering, maintaining, and updating of this CP or CPS. It also includes the name, electronic mail address, telephone number, and fax number of a contact person. As an alternative to naming an actual person, the document may name a title or role, an e-mail alias, and other generalized contact information. In some cases, the organization may state that its contact person, alone or in combination with others, is available to answer questions about the document. Moreover, when a formal or informal policy authority is responsible for determining whether a CA should be allowed to operate within or interoperate with a PKI, it may wish to approve the CPS of the CA as being suitable for the policy authority's CP. If so, this subcomponent can include the name or title, electronic mail address (or alias), telephone number, fax number, and other generalized information of the entity in charge of making such a determination. Finally, in this case, this subcomponent also includes the procedures by which this determination is made.4.1.6. Definitions and Acronyms
This subcomponent contains a list of definitions for defined terms used within the document, as well as a list of acronyms in the document and their meanings.
4.2. Publication and Repository Responsibilities
This component contains any applicable provisions regarding: * An identification of the entity or entities that operate repositories within the PKI, such as a CA, certificate manufacturing authority, or independent repository service provider; * The responsibility of a PKI participant to publish information regarding its practices, certificates, and the current status of such certificates, which may include the responsibilities of making the CP or CPS publicly available using various mechanisms and of identifying components, subcomponents, and elements of such documents that exist but are not made publicly available, for instance, security controls, clearance procedures, or trade secret information due to their sensitivity; * When information must be published and the frequency of publication; and * Access control on published information objects including CPs, CPS, certificates, certificate status, and CRLs.4.3. Identification and Authentication
This component describes the procedures used to authenticate the identity and/or other attributes of an end-user certificate applicant to a CA or RA prior to certificate issuance. In addition, the component sets forth the procedures for authenticating the identity and the criteria for accepting applicants of entities seeking to become CAs, RAs, or other entities operating in or interoperating with a PKI. It also describes how parties requesting re-key or revocation are authenticated. This component also addresses naming practices, including the recognition of trademark rights in certain names.4.3.1. Naming
This subcomponent includes the following elements regarding naming and identification of the subscribers: * Types of names assigned to the subject, such as X.500 distinguished names; RFC-822 names; and X.400 names; * Whether names have to be meaningful or not;(3)
* Whether or not subscribers can be anonymous or pseudonymous, and
if they can, what names are assigned to or can be used by
anonymous subscribers;
* Rules for interpreting various name forms, such as the X.500
standard and RFC-822;
* Whether names have to be unique; and
* Recognition, authentication, and the role of trademarks.
4.3.2. Initial Identity Validation
This subcomponent contains the following elements for the
identification and authentication procedures for the initial
registration for each subject type (CA, RA, subscriber, or other
participant):
* If and how the subject must prove possession of the companion
private key for the public key being registered, for example, a
digital signature in the certificate request message;(4)
* Identification and authentication requirements for organizational
identity of subscriber or participant (CA; RA; subscriber (in the
case of certificates issued to organizations or devices controlled
by an organization), or other participant), for example,
consulting the database of a service that identifies organizations
or inspecting an organization's articles of incorporation;
* Identification and authentication requirements for an individual
subscriber or a person acting on behalf of an organizational
subscriber or participant (CA, RA, in the case of certificates
issued to organizations or devices controlled by an organization,
the subscriber, or other participant),(5) including:
* Type of documentation and/or number of identification
credentials required;
* How a CA or RA authenticates the identity of the organization
or individual based on the documentation or credentials
provided;
* If the individual must personally present to the authenticating
CA or RA;
* How an individual as an organizational person is authenticated,
such as by reference to duly signed authorization documents or
a corporate identification badge.
* List of subscriber information that is not verified (called "non-
verified subscriber information") during the initial registration;
* Validation of authority involves a determination of whether a
person has specific rights, entitlements, or permissions,
including the permission to act on behalf of an organization to
obtain a certificate; and
* In the case of applications by a CA wishing to operate within, or
interoperate with, a PKI, this subcomponent contains the criteria
by which a PKI, CA, or policy authority determines whether or not
the CA is suitable for such operations or interoperation. Such
interoperation may include cross-certification, unilateral
certification, or other forms of interoperation.
4.3.3. Identification and Authentication for Re-key Requests
This subcomponent addresses the following elements for the
identification and authentication procedures for re-key for each
subject type (CA, RA, subscriber, and other participants):
* Identification and authentication requirements for routine re-key,
such as a re-key request that contains the new key and is signed
using the current valid key; and
* Identification and authentication requirements for re-key after
certificate revocation. One example is the use of the same
process as the initial identity validation.
4.3.4. Identification and Authentication for Revocation Requests
This subcomponent describes the identification and authentication
procedures for a revocation request by each subject type (CA, RA,
subscriber, and other participant). Examples include a revocation
request digitally signed with the private key whose companion public
key needs to be revoked, and a digitally signed request by the RA.
4.4. Certificate Life-Cycle Operational Requirements
This component is used to specify requirements imposed upon issuing
CA, subject CAs, RAs, subscribers, or other participants with respect
to the life-cycle of a certificate.
Within each subcomponent, separate consideration may need to be given
to subject CAs, RAs, subscribers, and other participants.
4.4.1. Certificate Application
This subcomponent is used to address the following requirements regarding subject certificate application: * Who can submit a certificate application, such as a certificate subject or the RA; and * Enrollment process used by subjects to submit certificate applications and responsibilities in connection with this process. An example of this process is where the subject generates the key pair and sends a certificate request to the RA. The RA validates and signs the request and sends it to the CA. A CA or RA may have the responsibility of establishing an enrollment process in order to receive certificate applications. Likewise, certificate applicants may have the responsibility of providing accurate information on their certificate applications.4.4.2. Certificate Application Processing
This subcomponent is used to describe the procedure for processing certificate applications. For example, the issuing CA and RA may perform identification and authentication procedures to validate the certificate application. Following such steps, the CA or RA will either approve or reject the certificate application, perhaps upon the application of certain criteria. Finally, this subcomponent sets a time limit during which a CA and/or RA must act on and process a certificate application.4.4.3. Certificate Issuance
This subcomponent is used to describe the following certificate issuance related elements: * Actions performed by the CA during the issuance of the certificate, for example a procedure whereby the CA validates the RA signature and RA authority and generates a certificate; and * Notification mechanisms, if any, used by the CA to notify the subscriber of the issuance of the certificate; an example is a procedure under which the CA e-mails the certificate to the subscriber or the RA or e-mails information permitting the subscriber to download the certificate from a web site.
4.4.4. Certificate Acceptance
This subcomponent addresses the following: * The conduct of an applicant that will be deemed to constitute acceptance of the certificate. Such conduct may include affirmative steps to indicate acceptance, actions implying acceptance, or a failure to object to the certificate or its content. For instance, acceptance may be deemed to occur if the CA does not receive any notice from the subscriber within a certain time period; a subscriber may send a signed message accepting the certificate; or a subscriber may send a signed message rejecting the certificate where the message includes the reason for rejection and identifies the fields in the certificate that are incorrect or incomplete. * Publication of the certificate by the CA. For example, the CA may post the certificate to an X.500 or LDAP repository. * Notification of certificate issuance by the CA to other entities. As an example, the CA may send the certificate to the RA.4.4.5. Key Pair and Certificate Usage
This subcomponent is used to describe the responsibilities relating to the use of keys and certificates, including: * Subscriber responsibilities relating to use of the subscriber's private key and certificate. For example, the subscriber may be required to use a private key and certificate only for appropriate applications as set forth in the CP and in consistency with applicable certificate content (e.g., key usage field). Use of a private key and certificate are subject to the terms of the subscriber agreement, the use of a private key is permitted only after the subscriber has accepted the corresponding certificate, or the subscriber must discontinue use of the private key following the expiration or revocation of the certificate. * Relying party responsibilities relating to the use of a subscriber's public key and certificate. For instance, a relying party may be obligated to rely on certificates only for appropriate applications as set forth in the CP and in consistency with applicable certificate content (e.g., key usage field), successfully perform public key operations as a condition of relying on a certificate, assume responsibility to check the status of a certificate using one of the required or permitted
mechanisms set forth in the CP/CPS (see Section 4.4.9 below), and
assent to the terms of the applicable relying party agreement as a
condition of relying on the certificate.
4.4.6. Certificate Renewal
This subcomponent is used to describe the following elements related
to certificate renewal. Certificate renewal means the issuance of a
new certificate to the subscriber without changing the subscriber or
other participant's public key or any other information in the
certificate:
* Circumstances under which certificate renewal takes place, such as
where the certificate life has expired, but the policy permits the
same key pair to be reused;
* Who may request certificate renewal, for instance, the subscriber,
RA, or the CA may automatically renew an end-user subscriber
certificate;
* A CA or RA's procedures to process renewal requests to issue the
new certificate, for example, the use of a token, such as a
password, to re-authenticate the subscriber, or procedures that
are the same as the initial certificate issuance;
* Notification of the new certificate to the subscriber;
* Conduct constituting acceptance of the certificate;
* Publication of the certificate by the CA; and
* Notification of certificate issuance by the CA to other entities.
4.4.7. Certificate Re-key
This subcomponent is used to describe the following elements related
to a subscriber or other participant generating a new key pair and
applying for the issuance of a new certificate that certifies the new
public key:
* Circumstances under which certificate re-key can or must take
place, such as after a certificate is revoked for reasons of key
compromise or after a certificate has expired and the usage period
of the key pair has also expired;
* Who may request certificate re-key, for example, the subscriber;
* A CA or RA's procedures to process re-keying requests to issue the
new certificate, such as procedures that are the same as the
initial certificate issuance;
* Notification of the new certificate to the subscriber;
* Conduct constituting acceptance of the certificate;
* Publication of the certificate by the CA; and
* Notification of certificate issuance by the CA to other entities.
4.4.8. Certificate Modification
This subcomponent is used to describe the following elements related
to the issuance of a new certificate (6) due to changes in the
information in the certificate other than the subscriber public key:
* Circumstances under which certificate modification can take place,
such as name change, role change, reorganization resulting in a
change in the DN;
* Who may request certificate modification, for instance,
subscribers, human resources personnel, or the RA;
* A CA or RA's procedures to process modification requests to issue
the new certificate, such as procedures that are the same as the
initial certificate issuance;
* Notification of the new certificate to the subscriber;
* Conduct constituting acceptance of the certificate;
* Publication of the certificate by the CA; and
* Notification of certificate issuance by the CA to other entities.
4.4.9. Certificate Revocation and Suspension
This subcomponent addresses the following:
* Circumstances under which a certificate may be suspended and
circumstances under which it must be revoked, for instance, in
cases of subscriber employment termination, loss of cryptographic
token, or suspected compromise of the private key;
* Who can request the revocation of the participant's certificate,
for example, the subscriber, RA, or CA in the case of an end-user
subscriber certificate.
* Procedures used for certificate revocation request, such as a
digitally signed message from the RA, a digitally signed message
from the subscriber, or a phone call from the RA;
* The grace period available to the subscriber, within which the
subscriber must make a revocation request;
* The time within which CA must process the revocation request;
* The mechanisms, if any, that a relying party may use or must use
in order to check the status of certificates on which they wish to
rely;
* If a CRL mechanism is used, the issuance frequency;
* If a CRL mechanism is used, maximum latency between the generation
of CRLs and posting of the CRLs to the repository (in other words,
the maximum amount of processing- and communication-related delays
in posting CRLs to the repository after the CRLs are generated);
* On-line revocation/status checking availability, for instance,
OCSP and a web site to which status inquiries can be submitted;
* Requirements on relying parties to perform on-line
revocation/status checks;
* Other forms of revocation advertisements available;
* Any variations of the above stipulations for which suspension or
revocation is the result of private key compromise (as opposed to
other reasons for suspension or revocation).
* Circumstances under which a certificate may be suspended;
* Who can request the suspension of a certificate, for example, the
subscriber, human resources personnel, a supervisor of the
subscriber, or the RA in the case of an end-user subscriber
certificate;
* Procedures to request certificate suspension, such as a digitally
signed message from the subscriber or RA, or a phone call from the
RA; and
* How long the suspension may last.
4.4.10. Certificate Status Services
This subcomponent addresses the certificate status checking services available to the relying parties, including: * The operational characteristics of certificate status checking services; * The availability of such services, and any applicable policies on unavailability; and * Any optional features of such services.4.4.11. End of Subscription
This subcomponent addresses procedures used by the subscriber to end subscription to the CA services, including: * The revocation of certificates at the end of subscription (which may differ, depending on whether the end of subscription was due to the expiration of the certificate or termination of the service).4.4.12. Key Escrow and Recovery
This subcomponent contains the following elements to identify the policies and practices relating to the escrowing, and/or recovery of private keys where private key escrow services are available (through the CA or other trusted third parties): * Identification of the document containing private key escrow and recovery policies and practices or a listing of such policies and practices; and * Identification of the document containing session key encapsulation and recovery policies and practices or a listing of such policies and practices.4.5. Management, Operational, and Physical Controls
This component describes non-technical security controls (that is, physical, procedural, and personnel controls) used by the issuing CA to securely perform the functions of key generation, subject authentication, certificate issuance, certificate revocation, auditing, and archiving.
This component can also be used to define non-technical security controls on repositories, subject CAs, RAs, subscribers, and other participants. The non-technical security controls for the subject CAs, RAs, subscribers, and other participants could be the same, similar, or very different. These non-technical security controls are critical to trusting the certificates since lack of security may compromise CA operations resulting for example, in the creation of certificates or CRLs with erroneous information or compromising the CA private key. Within each subcomponent, separate consideration will, in general, need to be given to each entity type, that is, the issuing CA, repository, subject CAs, RAs, subscribers, and other participants.4.5.1. Physical Security Controls
In this subcomponent, the physical controls on the facility housing the entity systems are described. Topics addressed may include: * Site location and construction, such as the construction requirements for high-security zones and the use of locked rooms, cages, safes, and cabinets; * Physical access, i.e., mechanisms to control access from one area of the facility to another or access into high-security zones, such as locating CA operations in a secure computer room monitored by guards or security alarms and requiring movement from zone to zone to be accomplished using a token, biometric readers, and/or access control lists; * Power and air conditioning; * Water exposures; * Fire prevention and protection; * Media storage, for example, requiring the storage of backup media in a separate location that is physically secure and protected from fire and water damage; * Waste disposal; and * Off-site backup.
4.5.2. Procedural Controls
In this subcomponent, requirements for recognizing trusted roles are described, together with the responsibilities for each role. Examples of trusted roles include system administrators, security officers, and system auditors. For each task identified, the number of individuals required to perform the task (n out m rule) should be stated for each role. Identification and authentication requirements for each role may also be defined. This component also includes the separation of duties in terms of the roles that cannot be performed by the same individuals.4.5.3. Personnel Security Controls
This subcomponent addresses the following: * Qualifications, experience, and clearances that personnel must have as a condition of filling trusted roles or other important roles. Examples include credentials, job experiences, and official government clearances that candidates for these positions must have before being hired; * Background checks and clearance procedures that are required in connection with the hiring of personnel filling trusted roles or perhaps other important roles; such roles may require a check of their criminal records, references, and additional clearances that a participant undertakes after a decision has been made to hire a particular person; * Training requirements and training procedures for each role following the hiring of personnel; * Any retraining period and retraining procedures for each role after completion of initial training; * Frequency and sequence for job rotation among various roles; * Sanctions against personnel for unauthorized actions, unauthorized use of authority, and unauthorized use of entity systems for the purpose of imposing accountability on a participant's personnel; * Controls on personnel that are independent contractors rather than employees of the entity; examples include: - Bonding requirements on contract personnel;
- Contractual requirements including indemnification for damages
due to the actions of the contractor personnel;
- Auditing and monitoring of contractor personnel; and
- Other controls on contracting personnel.
* Documentation to be supplied to personnel during initial training,
retraining, or otherwise.
4.5.4. Audit Logging Procedures
This subcomponent is used to describe event logging and audit
systems, implemented for the purpose of maintaining a secure
environment. Elements include the following:
* Types of events recorded, such as certificate lifecycle
operations, attempts to access the system, and requests made to
the system;
* Frequency with which audit logs are processed or archived, for
example, weekly, following an alarm or anomalous event, or when
ever the audit log is n% full;
* Period for which audit logs are kept;
* Protection of audit logs:
- Who can view audit logs, for example only the audit
administrator;
- Protection against modification of audit logs, for instance a
requirement that no one may modify or delete the audit records
or that only an audit administrator may delete an audit file as
part of rotating the audit file; and
- Protection against deletion of audit logs.
* Audit log back up procedures;
* Whether the audit log accumulation system is internal or external
to the entity;
* Whether the subject who caused an audit event to occur is notified
of the audit action; and
* Vulnerability assessments, for example, where audit data is run
through a tool that identifies potential attempts to breach the
security of the system.
4.5.5. Records Archival
This subcomponent is used to describe general records archival (or
records retention) policies, including the following:
* Types of records that are archived, for example, all audit data,
certificate application information, and documentation supporting
certificate applications;
* Retention period for an archive;
* Protection of an archive:
- Who can view the archive, for example, a requirement that only
the audit administrator may view the archive;
- Protection against modification of the archive, such as
securely storing the data on a write once medium;
- Protection against deletion of the archive;
- Protection against the deterioration of the media on which the
archive is stored, such as a requirement for data to be
migrated periodically to fresh media; and
- Protection against obsolescence of hardware, operating systems,
and other software, by, for example, retaining as part of the
archive the hardware, operating systems, and/or other software
in order to permit access to and use of archived records over
time.
* Archive backup procedures;
* Requirements for time-stamping of records;
* Whether the archive collection system is internal or external; and
* Procedures to obtain and verify archive information, such as a
requirement that two separate copies of the archive data be kept
under the control of two persons, and that the two copies be
compared in order to ensure that the archive information is
accurate.
4.5.6. Key Changeover
This subcomponent describes the procedures to provide a new public key to a CA's users following a re-key by the CA. These procedures may be the same as the procedure for providing the current key. Also, the new key may be certified in a certificate signed using the old key.4.5.7. Compromise and Disaster Recovery
This subcomponent describes requirements relating to notification and recovery procedures in the event of compromise or disaster. Each of the following may need to be addressed separately: * Identification or listing of the applicable incident and compromise reporting and handling procedures. * The recovery procedures used if computing resources, software, and/or data are corrupted or suspected to be corrupted. These procedures describe how a secure environment is re-established, which certificates are revoked, whether the entity key is revoked, how the new entity public key is provided to the users, and how the subjects are re-certified. * The recovery procedures used if the entity key is compromised. These procedures describe how a secure environment is re- established, how the new entity public key is provided to the users, and how the subjects are re-certified. * The entity's capabilities to ensure business continuity following a natural or other disaster. Such capabilities may include the availability of a remote hot-site at which operations may be recovered. They may also include procedures for securing its facility during the period of time following a natural or other disaster and before a secure environment is re-established, either at the original site or at a remote site. For example, procedures to protect against theft of sensitive materials from an earthquake-damaged site.4.5.8. CA or RA Termination
This subcomponent describes requirements relating to procedures for termination and termination notification of a CA or RA, including the identity of the custodian of CA and RA archival records.
4.6. Technical Security Controls
This component is used to define the security measures taken by the issuing CA to protect its cryptographic keys and activation data (e.g., PINs, passwords, or manually-held key shares). This component may also be used to impose constraints on repositories, subject CAs, subscribers, and other participants to protect their private keys, activation data for their private keys, and critical security parameters. Secure key management is critical to ensure that all secret and private keys and activation data are protected and used only by authorized personnel. This component also describes other technical security controls used by the issuing CA to perform securely the functions of key generation, user authentication, certificate registration, certificate revocation, auditing, and archiving. Technical controls include life-cycle security controls (including software development environment security, trusted software development methodology) and operational security controls. This component can also be used to define other technical security controls on repositories, subject CAs, RAs, subscribers, and other participants.4.6.1. Key Pair Generation and Installation
Key pair generation and installation need to be considered for the issuing CA, repositories, subject CAs, RAs, and subscribers. For each of these types of entities, the following questions potentially need to be answered: 1. Who generates the entity public, private key pair? Possibilities include the subscriber, RA, or CA. Also, how is the key generation performed? Is the key generation performed by hardware or software? 2. How is the private key provided securely to the entity? Possibilities include a situation where the entity has generated it and therefore already has it, handing the entity the private key physically, mailing a token containing the private key securely, or delivering it in an SSL session. 3. How is the entity's public key provided securely to the certification authority? Some possibilities are in an online SSL session or in a message signed by the RA.
4. In the case of issuing CAs, how is the CA's public key provided
securely to potential relying parties? Possibilities include
handing the public key to the relying party securely in person,
physically mailing a copy securely to the relying party, or
delivering it in a SSL session.
5. What are the key sizes? Examples include a 1,024 bit RSA modulus
and a 1,024 bit DSA large prime.
6. Who generates the public key parameters, and is the quality of the
parameters checked during key generation?
7. For what purposes may the key be used, or for what purposes should
usage of the key be restricted? For X.509 certificates, these
purposes should map to the key usage flags in X.509 Version 3
certificates.
4.6.2. Private Key Protection and Cryptographic Module Engineering
Controls
Requirements for private key protection and cryptographic modules
need to be considered for the issuing CA, repositories, subject CAs,
RAs, and subscribers. For each of these types of entities, the
following questions potentially need to be answered:
1. What standards, if any, are required for the cryptographic module
used to generate the keys? A cryptographic module can be
composed of hardware, software, firmware, or any combination of
them. For example, are the keys certified by the infrastructure
required to be generated using modules compliant with the US FIPS
140-1? If so, what is the required FIPS 140-1 level of the
module? Are there any other engineering or other controls
relating to a cryptographic module, such as the identification of
the cryptographic module boundary, input/output, roles and
services, finite state machine, physical security, software
security, operating system security, algorithm compliance,
electromagnetic compatibility, and self tests.
2. Is the private key under n out of m multi-person control?(7) If
yes, provide n and m (two person control is a special case of n
out of m, where n = m = 2)?
3. Is the private key escrowed?(8) If so, who is the escrow agent,
what form is the key escrowed in (examples include plaintext,
encrypted, split key), and what are the security controls on the
escrow system?
4. Is the private key backed up? If so, who is the backup agent,
what form is the key backed up in (examples include plaintext,
encrypted, split key), and what are the security controls on the
backup system?
5. Is the private key archived? If so, who is the archival agent,
what form is the key archived in (examples include plaintext,
encrypted, split key), and what are the security controls on the
archival system?
6. Under what circumstances, if any, can a private key be
transferred into or from a cryptographic module? Who is
permitted to perform such a transfer operation? In what form is
the private key during the transfer (i.e., plaintext, encrypted,
or split key)?
7. How is the private key stored in the module (i.e., plaintext,
encrypted, or split key)?
8. Who can activate (use) the private key? What actions must be
performed to activate the private key (e.g., login, power on,
supply PIN, insert token/key, automatic, etc.)? Once the key is
activated, is the key active for an indefinite period, active for
one time, or active for a defined time period?
9. Who can deactivate the private key and how? Examples of methods
of deactivating private keys include logging out, turning the
power off, removing the token/key, automatic deactivation, and
time expiration.
10. Who can destroy the private key and how? Examples of methods of
destroying private keys include token surrender, token
destruction, and overwriting the key.
11. Provide the capabilities of the cryptographic module in the
following areas: identification of the cryptographic module
boundary, input/output, roles and services, finite state machine,
physical security, software security, operating system security,
algorithm compliance, electromagnetic compatibility, and self
tests. Capability may be expressed through reference to
compliance with a standard such as U.S. FIPS 140-1, associated
level, and rating.
4.6.3. Other Aspects of Key Pair Management
Other aspects of key management need to be considered for the issuing CA, repositories, subject CAs, RAs, subscribers, and other participants. For each of these types of entities, the following questions potentially need to be answered: 1. Is the public key archived? If so, who is the archival agent and what are the security controls on the archival system? Also, what software and hardware need to be preserved as part of the archive to permit use of the public key over time? Note: this subcomponent is not limited to requiring or describing the use of digital signatures with archival data, but rather can address integrity controls other than digital signatures when an archive requires tamper protection. Digital signatures do not provide tamper protection or protect the integrity of data; they merely verify data integrity. Moreover, the archival period may be greater than the cryptanalysis period for the public key needed to verify any digital signature applied to archival data. 2. What is the operational period of the certificates issued to the subscriber. What are the usage periods, or active lifetimes, for the subscriber's key pair?4.6.4. Activation Data
Activation data refers to data values other than whole private keys that are required to operate private keys or cryptographic modules containing private keys, such as a PIN, passphrase, or portions of a private key used in a key-splitting scheme. Protection of activation data prevents unauthorized use of the private key, and potentially needs to be considered for the issuing CA, subject CAs, RAs, and subscribers. Such consideration potentially needs to address the entire life-cycle of the activation data from generation through archival and destruction. For each of the entity types (issuing CA, repository, subject CA, RA, subscriber, and other participants), all of the questions listed in 4.6.1 through 4.6.3 potentially need to be answered with respect to activation data rather than with respect to keys.4.6.5. Computer Security Controls
This subcomponent is used to describe computer security controls such as: use of the trusted computing base concept, discretionary access control, labels, mandatory access controls, object re-use, audit, identification and authentication, trusted path, security testing, and penetration testing. Product assurance may also be addressed.
A computer security rating for computer systems may be required. The rating could be based, for example, on the Trusted System Evaluation Criteria (TCSEC), Canadian Trusted Products Evaluation Criteria, European Information Technology Security Evaluation Criteria (ITSEC), or the Common Criteria for Information Technology Security Evaluation, ISO/IEC 15408:1999. This subcomponent can also address requirements for product evaluation analysis, testing, profiling, product certification, and/or product accreditation related activity undertaken.4.6.6. Life Cycle Security Controls
This subcomponent addresses system development controls and security management controls. System development controls include development environment security, development personnel security, configuration management security during product maintenance, software engineering practices, software development methodology, modularity, layering, use of failsafe design and implementation techniques (e.g., defensive programming) and development facility security. Security management controls include execution of tools and procedures to ensure that the operational systems and networks adhere to configured security. These tools and procedures include checking the integrity of the security software, firmware, and hardware to ensure their correct operation. This subcomponent can also address life-cycle security ratings based, for example, on the Trusted Software Development Methodology (TSDM) level IV and V, independent life-cycle security controls audit, and the Software Engineering Institute's Capability Maturity Model (SEI- CMM).4.6.7. Network Security Controls
This subcomponent addresses network security related controls, including firewalls.4.6.8. Time-stamping
This subcomponent addresses requirements or practices relating to the use of timestamps on various data. It may also discuss whether or not the time-stamping application must use a trusted time source.
4.7. Certificate and CRL Profiles
This component is used to specify the certificate format and, if CRLs and/or OCSP are used, the CRL and/or OCSP format. This includes information on profiles, versions, and extensions used.4.7.1. Certificate Profile
This subcomponent addresses such topics as the following (potentially by reference to a separate profile definition, such as the one defined in IETF PKIX RFC 3280): * Version number(s) supported; * Certificate extensions populated and their criticality; * Cryptographic algorithm object identifiers; * Name forms used for the CA, RA, and subscriber names; * Name constraints used and the name forms used in the name constraints; * Applicable CP OID(s); * Usage of the policy constraints extension; * Policy qualifiers syntax and semantics; and * Processing semantics for the critical CP extension.4.7.2. CRL Profile
This subcomponent addresses such topics as the following (potentially by reference to a separate profile definition, such as the one defined in IETF PKIX RFC 3280): * Version numbers supported for CRLs; and * CRL and CRL entry extensions populated and their criticality.4.7.3. OCSP Profile
This subcomponent addresses such topics as the following (potentially by reference to a separate profile definition, such as the IETF RFC 2560 profile):
* Version of OCSP that is being used as the basis for establishing
an OCSP system; and
* OCSP extensions populated and their criticality.
4.8. Compliance Audit and Other Assessment
This component addresses the following:
* The list of topics covered by the assessment and/or the assessment
methodology used to perform the assessment; examples include
WebTrust for CAs (9) and SAS 70 (10).
* Frequency of compliance audit or other assessment for each entity
that must be assessed pursuant to a CP or CPS, or the
circumstances that will trigger an assessment; possibilities
include an annual audit, pre-operational assessment as a condition
of allowing an entity to be operational, or investigation
following a possible or actual compromise of security.
* The identity and/or qualifications of the personnel performing the
audit or other assessment.
* The relationship between the assessor and the entity being
assessed, including the degree of independence of the assessor.
* Actions taken as a result of deficiencies found during the
assessment; examples include a temporary suspension of operations
until deficiencies are corrected, revocation of certificates
issued to the assessed entity, changes in personnel, triggering
special investigations or more frequent subsequent compliance
assessments, and claims for damages against the assessed entity.
* Who is entitled to see results of an assessment (e.g., assessed
entity, other participants, the general public), who provides them
(e.g., the assessor or the assessed entity), and how they are
communicated.
4.9. Other Business and Legal Matters
This component covers general business and legal matters. Sections
9.1 and 9.2 of the framework discuss the business issues of fees to
be charged for various services and the financial responsibility of
participants to maintain resources for ongoing operations and for
paying judgments or settlements in response to claims asserted
against them. The remaining sections are generally concerned with
legal topics.
Starting with Section 9.3 of the framework, the ordering of topics is the same as or similar to the ordering of topics in a typical software licensing agreement or other technology agreement. Consequently, this framework may not only be used for CPs and CPSs, but also associated PKI-related agreements, especially subscriber agreements, and relying party agreements. This ordering is intended help lawyers review CPs, CPSs, and other documents adhering to this framework. With respect to many of the legal subcomponents within this component, a CP or CPS drafter may choose to include in the document terms and conditions that apply directly to subscribers or relying parties. For instance, a CP or CPS may set forth limitations of liability that apply to subscribers and relying parties. The inclusion of terms and conditions is likely to be appropriate where the CP or CPS is itself a contract or part of a contract. In other cases, however, the CP or CPS is not a contract or part of a contract; instead, it is configured so that its terms and conditions are applied to the parties by separate documents, which may include associated agreements, such as subscriber or relying party agreements. In that event, a CP drafter may write a CP so as to require that certain legal terms and conditions appear (or not appear) in such associated agreements. For example, a CP might include a subcomponent stating that a certain limitation of liability term must appear in a CA's subscriber and relying party agreements. Another example is a CP that contains a subcomponent prohibiting the use of a subscriber or relying party agreement containing a limitation upon CA liability inconsistent with the provisions of the CP. A CPS drafter may use legal subcomponents to disclose that certain terms and conditions appear in associated subscriber, relying party, or other agreements in use by the CA. A CPS might explain, for instance, that the CA writing it uses an associated subscriber or relying party agreement that applies a particular provision for limiting liability.4.9.1. Fees
This subcomponent contains any applicable provisions regarding fees charged by CAs, repositories, or RAs, such as: * Certificate issuance or renewal fees; * Certificate access fees; * Revocation or status information access fees;
* Fees for other services such as providing access to the relevant
CP or CPS; and
* Refund policy.
4.9.2. Financial Responsibility
This subcomponent contains requirements or disclosures relating to
the resources available to CAs, RAs, and other participants providing
certification services to support performance of their operational
PKI responsibilities, and to remain solvent and pay damages in the
event they are liable to pay a judgment or settlement in connection
with a claim arising out of such operations. Such provisions
include:
* A statement that the participant maintains a certain amount of
insurance coverage for its liabilities to other participants;
* A statement that a participant has access to other resources to
support operations and pay damages for potential liability, which
may be couched in terms of a minimum level of assets necessary to
operate and cover contingencies that might occur within a PKI,
where examples include assets on the balance sheet of an
organization, a surety bond, a letter of credit, and a right under
an agreement to an indemnity under certain circumstances; and
* A statement that a participant has a program that offers first-
party insurance or warranty protection to other participants in
connection with their use of the PKI.
4.9.3. Confidentiality of Business Information
This subcomponent contains provisions relating to the treatment of
confidential business information that participants may communicate
to each other, such as business plans, sales information, trade
secrets, and information received from a third party under a
nondisclosure agreement. Specifically, this subcomponent addresses:
* The scope of what is considered confidential information,
* The types of information that are considered to be outside the
scope of confidential information, and
* The responsibilities of participants that receive confidential
information to secure it from compromise, and refrain from using
it or disclosing it to third parties.
4.9.4. Privacy of Personal Information
This subcomponent relates to the protection that participants, particularly CAs, RAs, and repositories, may be required to afford to personally identifiable private information of certificate applicants, subscribers, and other participants. Specifically, this subcomponent addresses the following, to the extent pertinent under applicable law: * The designation and disclosure of the applicable privacy plan that applies to a participant's activities, if required by applicable law or policy; * Information that is or is not considered private within the PKI; * Any responsibility of participants that receive private information to secure it, and refrain from using it and from disclosing it to third parties; * Any requirements as to notices to, or consent from individuals regarding use or disclosure of private information; and * Any circumstances under which a participant is entitled or required to disclose private information pursuant to judicial, administrative process in a private or governmental proceeding, or in any legal proceeding.4.9.5. Intellectual Property Rights
This subcomponent addresses the intellectual property rights, such as copyright, patent, trademarks, or trade secrets, that certain participants may have or claim in a CP, CPS, certificates, names, and keys, or are the subject of a license to or from participants.4.9.6. Representations and Warranties
This subcomponent can include representations and warranties of various entities that are being made pursuant to the CP or CPS. For example, a CPS that serves as a contract might contain a CA's warranty that information contained in the certificate is accurate. Alternatively, a CPS might contain a less extensive warranty to the effect that the information in the certificate is true to the best of the CA's knowledge after performing certain identity authentication procedures with due diligence. This subcomponent can also include requirements that representations and warranties appear in certain agreements, such as subscriber or relying party agreements. For instance, a CP may contain a requirement that all CAs utilize a subscriber agreement, and that a subscriber agreement must contain a
warranty by the CA that information in the certificate is accurate. Participants that may make representations and warranties include CAs, RAs, subscribers, relying parties, and other participants.4.9.7. Disclaimers of Warranties
This subcomponent can include disclaimers of express warranties that may otherwise be deemed to exist in an agreement, and disclaimers of implied warranties that may otherwise be imposed by applicable law, such as warranties of merchantability or fitness for a particular purpose. The CP or CPS may directly impose such disclaimers, or the CP or CPS may contain a requirement that disclaimers appear in associated agreements, such as subscriber or relying party agreements.4.9.8. Limitations of Liability
This subcomponent can include limitations of liability in a CP or CPS or limitations that appear or must appear in an agreement associated with the CP or CPS, such as a subscriber or relying party agreement. These limitations may fall into one of two categories: limitations on the elements of damages recoverable and limitations on the amount of damages recoverable, also known as liability caps. Often, contracts contain clauses preventing the recovery of elements of damages such as incidental and consequential damages, and sometimes punitive damages. Frequently, contracts contain clauses that limit the possible recovery of one party or the other to an amount certain or to an amount corresponding to a benchmark, such as the amount a vendor was paid under the contract.4.9.9. Indemnities
This subcomponent includes provisions by which one party makes a second party whole for losses or damage incurred by the second party, typically arising out of the first party's conduct. They may appear in a CP, CPS, or agreement. For example, a CP may require that subscriber agreements contain a term under which a subscriber is responsible for indemnifying a CA for losses the CA sustains arising out of a subscriber's fraudulent misrepresentations on the certificate application under which the CA issued the subscriber an inaccurate certificate. Similarly, a CPS may say that a CA uses a relying party agreement, under which relying parties are responsible for indemnifying a CA for losses the CA sustains arising out of use of a certificate without properly checking revocation information or use of a certificate for purposes beyond what the CA permits.
4.9.10. Term and Termination
This subcomponent can include the time period in which a CP or a CPS remains in force and the circumstances under which the document, portions of the document, or its applicability to a particular participant can be terminated. In addition or alternatively, the CP or CPS may include requirements that certain term and termination clauses appear in agreements, such as subscriber or relying party agreements. In particular, such terms can include: * The term of a document or agreement, that is, when the document becomes effective and when it expires if it is not terminated earlier. * Termination provisions stating circumstances under which the document, certain portions of it, or its application to a particular participant ceases to remain in effect. * Any consequences of termination of the document. For example, certain provisions of an agreement may survive its termination and remain in force. Examples include acknowledgements of intellectual property rights and confidentiality provisions. Also, termination may trigger a responsibility of parties to return confidential information to the party that disclosed it.4.9.11. Individual notices and communications with participants
This subcomponent discusses the way in which one participant can or must communicate with another participant on a one-to-one basis in order for such communications to be legally effective. For example, an RA may wish to inform the CA that it wishes to terminate its agreement with the CA. This subcomponent is different from publication and repository functions, because unlike individual communications described in this subcomponent, publication and posting to a repository are for the purpose of communicating to a wide audience of recipients, such as all relying parties. This subcomponent may establish mechanisms for communication and indicate the contact information to be used to route such communications, such as digitally signed e-mail notices to a specified address, followed by a signed e-mail acknowledgement of receipt.4.9.12. Amendments
It will occasionally be necessary to amend a CP or CPS. Some of these changes will not materially reduce the assurance that a CP or its implementation provides, and will be judged by the policy administrator to have an insignificant effect on the acceptability of certificates. Such changes to a CP or CPS need not require a change
in the CP OID or the CPS pointer (URL). On the other hand, some
changes to a specification will materially change the acceptability
of certificates for specific purposes, and these changes may require
corresponding changes to the CP OID or CPS pointer qualifier (URL).
This subcomponent may also contain the following information:
* The procedures by which the CP or CPS and/or other documents must,
may be, or are amended. In the case of CP or CPS amendments,
change procedures may include a notification mechanism to provide
notice of proposed amendments to affected parties, such as
subscribers and relying parties, a comment period, a mechanism by
which comments are received, reviewed and incorporated into the
document, and a mechanism by which amendments become final and
effective.
* The circumstances under which amendments to the CP or CPS would
require a change in CP OID or CPS pointer (URL).
4.9.13. Dispute Resolution Procedures
This subcomponent discusses procedures utilized to resolve disputes
arising out of the CP, CPS, and/or agreements. Examples of such
procedures include requirements that disputes be resolved in a
certain forum or by alternative dispute resolution mechanisms.
4.9.14. Governing Law
This subcomponent sets forth a statement that the law of a certain
jurisdiction governs the interpretation and enforcement of the
subject CP or CPS or agreements.
4.9.15. Compliance with Applicable Law
This subcomponent relates to stated requirements that participants
comply with applicable law, for example, laws relating to
cryptographic hardware and software that may be subject to the export
control laws of a given jurisdiction. The CP or CPS could purport to
impose such requirements or may require that such provisions appear
in other agreements.
4.9.16. Miscellaneous Provisions
This subcomponent contains miscellaneous provisions, sometimes called
"boilerplate provisions," in contracts. The clauses covered in this
subcomponent may appear in a CP, CPS, or agreements and include:
* An entire agreement clause, which typically identifies the
document or documents comprising the entire agreement between the
parties and states that such agreements supersede all prior and
contemporaneous written or oral understandings relating to the
same subject matter;
* An assignment clause, which may act to limit the ability of a
party in an agreement, assigning its rights under the agreement to
another party (such as the right to receive a stream of payments
in the future) or limiting the ability of a party to delegate its
obligations under the agreement;
* A severability clause, which sets forth the intentions of the
parties in the event that a court or other tribunal determines
that a clause within an agreement is, for some reason, invalid or
unenforceable, and whose purpose is frequently to prevent the
unenforceability of one clause from causing the whole agreement to
be unenforceable; and
* An enforcement clause, which may state that a party prevailing in
any dispute arising out of an agreement is entitled to attorneys'
fees as part of its recovery, or may state that a party's waiver
of one breach of contract does not constitute a continuing waiver
or a future waiver of other breaches of contract.
* A force majeure clause, commonly used to excuse the performance of
one or more parties to an agreement due to an event outside the
reasonable control of the affected party or parties. Typically,
the duration of the excused performance is commensurate with the
duration of the delay caused by the event. The clause may also
provide for the termination of the agreement under specified
circumstances and conditions. Events considered to constitute a
"force majeure" may include so-called "Acts of God," wars,
terrorism, strikes, natural disasters, failures of suppliers or
vendors to perform, or failures of the Internet or other
infrastructure. Force majeure clauses should be drafted so as to
be consistent with other portions of the framework and applicable
service level agreements. For instance, responsibilities and
capabilities for business continuity and disaster recovery may
place some events within the reasonable control of the parties,
such as an obligation to maintain backup electrical power in the
face of power outages.
4.9.17. Other Provisions
This subcomponent is a "catchall" location where additional responsibilities and terms can be imposed on PKI participants that do not neatly fit within one of the other components or subcomponents of the framework. CP and CPS writers can place any provision within this subcomponent that is not covered by another subcomponent.