Siemens Product PKI Certificate Management Service – Certificate Policy for Siemens Product PKI Infrastructure Certificates
Siemens AG · Version V2.1
Document History
| Version | Date | Author | Change Comment |
|---|---|---|---|
| 1.0 | Jan. 26, 2022 | Michael Munzert Antonio Vaira |
First released version |
| 1.1 | Oct. 11, 2022 | Kai Che Michael Munzert |
New responsible for document authorization |
| 1.2 | Mar. 02, 2023 | Kai Che Michael Munzert Antonio Vaira |
Detailed Chapter 6 key generation |
| 2.0 | Oct. 18, 2023 | Kai Che Michael Munzert Antonio Vaira |
Copied parts of the description of the Central CP to Tenant CP (this document). Added explanation of the meaning of OIDs in Chapter 7.1.6. |
| 2.0 | July 10, 2024 | Kai Che | Review performed, no changes. |
| 2.1 | Jan. 30, 2025 | Kai Che | Updated department from T CST to FT RPD CST due to reorganization. |
This document will be reviewed every year or in the event of an important ad-hoc change according to the Information Security update process for documents. Each new version will be approved by the respective management level before being released. This document is published under www.siemens.com/pki
Scope and Applicability
This document constitutes the Certificate Policy (CP) for the PKI service providing infrastructure certificates to Siemens Product PKI Tenant. The Product PKI is responsible for the operation of the Root CAs as well as for the Issuing CAs. Together with the Central CP, this document discloses to interested parties the business policies and practices under which the Product PKI operates. The Central PMA ensures that the certification practices established to meet the applicable requirements specified in the present document are properly implemented in accordance with Siemens' Information Security Policy.
Document Status
This document has been classified as "Unrestricted".
| Name | Department | Date | |
|---|---|---|---|
| Author | Various authors, detailed information see document history. | ||
| Checked by | Stenger, Meiko Kuechler, Markus |
Siemens LC Siemens IT |
May, 2020 Feb., 2022 |
| Authorization | Dr. Kind, Andreas | Head of Siemens FT RPD CST | Jan., 2025 |
Content
- Document History
- Scope and Applicability
- Document Status
- Content
- 1 Introduction
- 1.1 Overview
- 1.1.1 PKI hierarchy
- 1.2 Document Name and Identification
- 1.3 PKI Participants
- 1.3.1 Certification Authorities
- 1.3.2 Registration Authorities
- 1.3.3 Subscribers
- 1.3.4 Relying Parties
- 1.3.5 Other Participants
- 1.4 Certificate Usage
- 1.4.1 Appropriate Certificate Usage
- 1.4.2 Prohibited Certificate Usage
- 1.5 Policy Administration
- 1.5.1 Organization Administering the Document
- 1.5.2 Contact Person
- 1.5.3 Person Determining CP and CPS Suitability for the Policy
- 1.5.4 CPS Approval Procedures
- 1.6 Definitions and Acronyms
- 1.6.1 Definitions
- 1.6.2 Acronyms
- 2 Publication and Repository Responsibilities
- 2.1 Repositories
- 2.2 Publication of Certification Information
- 2.3 Time or Frequency of Publication
- 2.4 Access Controls on Repositories
- 3 Identification and Authentication
- 3.1 Naming
- 3.1.1 Types of Names
- 3.1.2 Need of Names to be Meaningful
- 3.1.3 Anonymity or Pseudonymity of Subscribers
- 3.1.4 Rules for Interpreting Various Name Forms
- 3.1.5 Uniqueness of Names
- 3.1.6 Recognition, Authentication, and Roles of Trademarks
- 3.2 Initial Identity Validation
- 3.2.1 Method to Prove Possession of Private Key
- 3.2.2 Authentication of Organization Identity
- 3.2.3 Authentication of Individual Identity
- 3.2.4 Non-verified Subscriber Information
- 3.2.5 Validation of Authority
- 3.2.6 Criteria for Interoperation
- 3.2.7 Identification and Authentication for Re-key Requests
- 3.2.8 Identification and Authentication for Routine Re-Key
- 3.2.9 Identification and Authentication for Re-Key After Revocation
- 3.3 Identification and Authentication for Revocation Requests
- 4 Certificate Lifecycle Operational Requirements
- 4.1 Certificate Application
- 4.1.1 Who can submit a certificate application?
- 4.1.2 Enrollment Process and Responsibilities
- 4.2 Certificate Application Processing
- 4.2.1 Performing identification and authentication functions
- 4.2.2 Approval or Rejection of Certificate Applications
- 4.2.3 Time to Process Certificate Applications
- 4.3 Certificate Issuance
- 4.3.1 CA Actions during Certificate Issuance
- 4.3.2 Notification to Subscriber by the CA of Issuance of Certificate
- 4.4 Certificate Acceptance
- 4.4.1 Conduct constituting certificate acceptance
- 4.4.2 Publication of the certificate by the CA
- 4.4.3 Notification of Certificate issuance by the CA to other entities
- 4.5 Key Pair and Certificate Usage
- 4.5.1 Subject Private Key and Certificate Usage
- 4.5.2 Relying Party Public Key and Certificate Usage
- 4.6 Certificate Renewal
- 4.6.1 Circumstance for Certificate Renewal
- 4.6.2 Who may request renewal?
- 4.6.3 Processing Certificate Renewal Request
- 4.6.4 Notification of new Certificate Issuance to Subscriber
- 4.6.5 Conduct Constituting Acceptance of a Renewal Certificate
- 4.6.6 Publication of the Renewal Certificate by the CA
- 4.6.7 Notification of Certificate Issuance by the CA to other Entities
- 4.7 Certificate Re-key
- 4.7.1 Circumstances for Certificate Re-key
- 4.7.2 Who may request certification of a new Public Key?
- 4.7.3 Processing Certificate Re-keying Requests
- 4.7.4 Notification of new Certificate Issuance to Subscriber
- 4.7.5 Conduct Constituting Acceptance of a Re-keyed Certificate
- 4.7.6 Publication of the Re-keyed Certificate by the CA
- 4.7.7 Notification of Certificate Issuance by the CA to other Entities
- 4.8 Certificate Modification
- 4.8.1 Circumstance for Certificate Modification
- 4.8.2 Who may request Certificate modification?
- 4.8.3 Processing Certificate Modification Requests
- 4.8.4 Notification of new Certificate Issuance to Subscriber
- 4.8.5 Conduct Constituting Acceptance of Modified Certificate
- 4.8.6 Publication of the Modified Certificate by the CA
- 4.8.7 Notification of Certificate Issuance by the CA to Other Entities
- 4.9 Certificate Revocation and Suspension
- 4.9.1 Circumstances for Revocation
- 4.9.2 Who can request revocation?
- 4.9.3 Procedure for Revocation Request
- 4.9.4 Revocation Request Grace Period
- 4.9.5 Time within which CA must Process the Revocation Request
- 4.9.6 Revocation Checking Requirement for Relying Parties
- 4.9.7 CRL Issuance Frequency
- 4.9.8 Maximum Latency for CRLs
- 4.9.9 On-line Revocation/Status Checking Availability
- 4.9.10 On-line Revocation Checking Requirements
- 4.9.11 Other Forms of Revocation Advertisements Available
- 4.9.12 Special Requirements for Private Key Compromise
- 4.9.13 Circumstances for Suspension
- 4.9.14 Who can request suspension?
- 4.9.15 Procedure for suspension request
- 4.9.16 Limits on suspension period
- 4.10 Certificate Status Services
- 4.10.1 Operational Characteristics
- 4.10.2 Service Availability
- 4.10.3 Optional Features
- 4.11 End of Subscription
- 4.12 Key Escrow and Recovery
- 4.12.1 Key Escrow and Recovery Policy and Practices
- 4.12.2 Session Key Encapsulation and Recovery Policy and Practices
- 5 Management, Operational, and Physical Controls
- 5.1 Physical Security Controls
- 5.1.1 Site Location and Construction
- 5.1.2 Physical Access
- 5.1.3 Power and Air Conditioning
- 5.1.4 Water Exposure
- 5.1.5 Fire Prevention and Protection
- 5.1.6 Media Storage
- 5.1.7 Waste Disposal
- 5.1.8 Off-site Backup
- 5.2 Procedural Controls
- 5.2.1 Trusted Roles
- 5.2.2 Numbers of Persons Required per Task
- 5.2.3 Identification and Authentication for Each Role
- 5.2.4 Roles Requiring Separation of Duties
- 5.3 Personnel Controls
- 5.3.1 Qualifications, Experience and Clearance Requirements
- 5.3.2 Background Check Procedures
- 5.3.3 Training Requirements
- 5.3.4 Retraining Frequency and Requirements
- 5.3.5 Job Rotation Frequency and Sequence
- 5.3.6 Sanctions for Unauthorized Actions
- 5.3.7 Independent Contractor Requirements
- 5.3.8 Documents Supplied to Personnel
- 5.4 Audit Logging Procedures
- 5.4.1 Types of Events Recorded
- 5.4.2 Frequency of Processing Log
- 5.4.3 Retention Period for Audit Log
- 5.4.4 Protection of Audit Log
- 5.4.5 Audit Log Backup Procedures
- 5.4.6 Audit Collection System (Internal vs. External)
- 5.4.7 Notification to Event-Causing Subject
- 5.4.8 Vulnerability Assessments
- 5.5 Records Archival
- 5.5.1 Types of Records Archived
- 5.5.2 Retention Period for Archived Audit Logging Information
- 5.5.3 Protection of Archive
- 5.5.4 Archive Backup Procedures
- 5.5.5 Requirements for Time-Stamping of Record
- 5.5.6 Archive Collection System (internal or external)
- 5.5.7 Procedures to Obtain and Verify Archived Information
- 5.6 Key Changeover
- 5.7 Compromise and Disaster Recovery
- 5.7.1 Incident and Compromise Handling Procedures
- 5.7.2 Corruption of Computing Resources, Software, and/or Data
- 5.7.3 Entity Private Key Compromise Procedures
- 5.7.4 Business Continuity Capabilities After a Disaster
- 5.8 CA or RA Termination
- 6 Technical Security Controls
- 6.1 Key Pair Generation and Installation
- 6.1.1 Key Pair Generation
- 6.1.2 Private Key Delivery to Subscriber
- 6.1.3 Public Key Delivery to Certificate Issuer
- 6.1.4 CA Public Key Delivery to Relying Parties
- 6.1.5 Key Sizes
- 6.1.6 Public Key Parameters Generation and Quality Checking
- 6.1.7 Key Usage Purposes (as per X.509 v3 Key Usage Field)
- 6.2 Private Key Protection and Cryptographic Module Engineering Controls
- 6.2.1 Cryptographic Module Standards and Controls
- 6.2.2 Private Key (n out of m) Multi-person Control
- 6.2.3 Private Key Escrow
- 6.2.4 Private Key Backup
- 6.2.5 Private Key Archival
- 6.2.6 Private Key Transfer into or from a Cryptographic Module
- 6.2.7 Private Key Storage on Cryptographic Module
- 6.2.8 Method of Activating Private Key
- 6.2.9 Method of Deactivating Private Key
- 6.2.10 Method of Destroying Private Key
- 6.2.11 Cryptographic Module Rating
- 6.3 Other Aspects of Key Pair Management
- 6.3.1 Public key archival
- 6.3.2 Certificate operational periods and key pair usage periods
- 6.4 Activation Data
- 6.4.1 Activation Data Generation and Installation
- 6.4.2 Activation Data Protection
- 6.4.3 Other Aspects of Activation Data
- 6.5 Computer Security Controls
- 6.5.1 Specific Computer Security Technical Requirements
- 6.5.2 Computer Security Rating
- 6.6 Life Cycle Security Controls
- 6.6.1 System Development Controls
- 6.6.2 Security Management Controls
- 6.6.3 Life Cycle Security Controls
- 6.7 Network Security Controls
- 6.8 Time Stamp Process
- 7 Certificate, CRL, and OCSP Profiles
- 7.1 Certificate Profile
- 7.1.1 Version Number(s)
- 7.1.2 Certificate Extensions
- 7.1.3 Algorithm Object Identifiers
- 7.1.4 Name Forms
- 7.1.5 Name Constraints
- 7.1.6 Certificate Policy Object Identifier
- 7.1.7 Usage of Policy Constraints Extension
- 7.1.8 Policy Qualifiers Syntax and Semantics
- 7.1.9 Processing Semantics for the Critical Certificate Policies Extension
- 7.2 CRL Profile
- 7.2.1 Version number(s)
- 7.2.2 CRL and CRL entry extensions
- 7.3 OCSP Profile
- 7.3.1 Version Number(s)
- 7.3.2 OCSP Extension
- 8 Compliance Audit and Other Assessment
- 8.1 Frequency or Circumstances of Assessment
- 8.2 Identity / Qualifications of Assessor
- 8.3 Assessor’s Relationship to Assessed Entity
- 8.4 Topics Covered by Assessment
- 8.5 Actions Taken as a Result of Deficiency
- 8.6 Communication of Results
- 9 Other Business and Legal Matters
- 9.1 Fees
- 9.1.1 Certificate Issuance or Renewal fees
- 9.1.2 Certificate Access fees
- 9.1.3 Revocation or Status Information Access fees
- 9.1.4 Fees for other Services
- 9.1.5 Refund Policy
- 9.2 Financial Responsibility
- 9.2.1 Insurance Coverage
- 9.2.2 Other Assets
- 9.2.3 Insurance or Warranty Coverage for End-Entities
- 9.3 Confidentiality of Business Information
- 9.3.1 Scope of Confidential Information
- 9.3.2 Information not within the Scope of Confidential Information
- 9.3.3 Responsibility to Protect Confidential Information
- 9.4 Privacy of Personal Information
- 9.4.1 Privacy plan
- 9.4.2 Information treated as private
- 9.4.3 Information not deemed private
- 9.4.4 Responsibility to protect private information
- 9.4.5 Notice and consent to use private information
- 9.4.6 Disclosure pursuant to judicial or administrative process
- 9.4.7 Other information disclosure circumstances
- 9.5 Intellectual Property Rights
- 9.5.1 Intellectual Property Rights in Certificates and Revocation Information
- 9.5.2 Intellectual Property Rights in CP
- 9.5.3 Intellectual Property Rights in Names
- 9.5.4 Property rights of Certificate Owners
- 9.6 Representations and Warranties
- 9.6.1 CA representations and warranties
- 9.6.2 RA representations and warranties
- 9.6.3 Subscriber representations and warranties
- 9.6.4 Relying party representations and warranties
- 9.6.5 Representations and warranties of other participants
- 9.7 Disclaimers of Warranties
- 9.8 Limitations of Liability
- 9.9 Indemnities
- 9.10 Term and Termination
- 9.10.1 Term
- 9.10.2 Termination
- 9.10.3 Effect of Termination and Survival
- 9.11 Individual Notices and Communication with Participants
- 9.12 Amendments
- 9.12.1 Procedure for Amendment
- 9.12.2 Notification Mechanism and Period
- 9.12.3 Circumstances under which OID must be changed
- 9.13 Dispute Resolution Provisions
- 9.14 Governing Law
- 9.15 Compliance with Applicable Law
- 9.16 Miscellaneous Provisions
- 9.16.1 Entire Agreement
- 9.16.2 Assignment
- 9.16.3 Severability
- 9.16.4 Enforcement (attorneys' fees and waiver of rights)
- 9.16.5 Force Majeure
- 9.17 Other Provisions
- 9.17.1 Order of Precedence of CP
- 10 References
Introduction
This document is structured according to RFC 3647 “Internet X.509 Public Key Infrastructure: Certificate Policy and Certification Practices Framework” [RFC3647]. The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] even in case the keywords are not capitalized.
1.1 Overview
This document describes the Certificate Policy of the Siemens Product PKI Certificate Management Service (in the following called “Product PKI”) of the Tenant providing Infrastructure Certificates for all other Product PKI Tenants. Together with the central CP [CCP] it describes the services provided by the Product PKI as well as binding requirements that must be fulfilled by Product PKI participants. In case there are no additional requirements defined by the tenant (in this document, i.e. Tenant CP), the respective section will refer to the Central CP. In case specific requirements are listed they will apply in addition to the requirements set forth in the Central CP. Under no circumstances, provisions set forth in this document can weaken the requirements set forth in the Central CP. Moreover - together with the CPSs – the CPs also define the certification process as well as the cooperation, duties and rights of the respective Product PKI participants. The Product PKI is a PKI that provides and manages certificates (e.g. “IDevID certificates” or “Manufacturer Device certificates”) that are stored on and used by Siemens products and solutions. The private key might be used in bootstrapping scenarios for authentication purposes. Or the certificate might be used to proof that the device is a genuine Siemens device. Unless otherwise stated, the term “Product PKI” or any of its entities, refer to “Siemens Product PKI Certificate Management Service”, or any of its respective entities, for the rest of this Certificate Policy. Since different stakeholders are involved, also responsibilities are distributed between these stakeholders:
- Product PKI Governance: responsible for the Product PKI service is the organization listed in section 1.5 Policy Administration.
-
IT Services: The central Product PKI service is hosted in the Siemens Trust Center that is operated and managed by Siemens IT department.
-
Tenant: Tenant can be every Siemens AG organizational unit or any other legal entity that has a contract in place that covers Product PKI services. The Tenants typically operate and maintain the registrations authorities (e.g. within their production facilities or data center). Therefore, the Tenants are responsible for RA operation and End-Entity authentication.
| Trust Center Responsibility: PPKI governance |
⇔ | Tenant: e.g. Production Site Responsibility: Tenant |
|---|---|---|
| PPKI Services | ⇐⇒ | RA → End Entity (e.g. device) |
Figure 1: Stakeholders and typical responsibility split In accordance with this responsibility split, there are two Certificate Policies, one for the central part of the Product PKI (Central CP) and additional ones for the Tenant specific aspects (this document). The same holds for the corresponding Certification Practice Statements (CPSs). The Tenant specific CP is always the master document. It defines all requirements for which the Tenant is responsible for. In particular, it comprises the management and operation of the RAs and/or LRAs, of publicly accessible repositories. Where appropriate, the Tenant specific CP will also refer to requirements valid for the operation of the central service. In that case the phrase “See also Central CP for central service aspects”. In those sections that are not relevant for the Tenant, it is referred to the central CP by using the phrase “See central CP”. The Tenant specific CP is supplemented with the Central CP. In particular, the Central CP comprises all requirements for the management and operation of the Central PKI System including Root CA and Issuing CAs. The Tenant CPS describes how the requirements defined in the Tenant CP are implemented. In addition, the Central CPS supplements how the requirements defined in the Central CP are implemented. The different documents and their interrelation are depicted in the following figure:
| Scope | Certificate Policy (defines what) | Certification Practice Statement (defines how) | |
|---|---|---|---|
| Central (Trust Center / Root & Issuing CAs) | Central CP (this document) |
⟶ implemented by ⟶ | Central CPS |
| ⇧ supplements | ⇧ supplements | ||
| Tenant (RA / LRA / End Entities) | Tenant CP (master document) |
⟶ implemented by ⟶ | Tenant CPS |
Figure 2: Document structure (CP and CPS). The Tenant CP is the master document; the Central CP supplements it. Each CP is implemented by its corresponding CPS.
In addition to the requirements defined in this CP and the corresponding CPSs, Siemens IT systems are operated according to the Siemens internal information security rules and respective execution guidelines, which define how IT systems must be operated securely. The corresponding documents can be retrieved on request. These rules are part of a Siemens ISMS [ISMS], which is defined and implemented according to ISO 27001.
1.1.1 PKI hierarchy
The specific PKI hierarchy is shown in Figure 3.
| Tier | CA |
|---|---|
| Root (offline, self-signed) | PPKI Infrastructure Root CA Vx.x |
| ⬇ signs | |
| Issuing | PPKI Infrastructure Issuing CA Vx.x |
Figure 3: PPKI hierarchy for Infrastructure Certificates
The Issuing CA for Siemens Product PKI Infrastructure Certificates issues certificates that are used (together with the corresponding private keys) to identify and authenticate the different Tenants to provide the right, Tenant specific services (e.g. issuing CAs). These certificates are typically deployed on Local RAs, managed by the Tenants, but also on PPKI core components to correctly identify them and guarantee authenticated and integrity protected connections between the Tenants and the PPKI component, e.g. CMP gateway, or any generic PPKI servers.
1.2 Document Name and Identification
This CP is referred to as Certificate Policy for the ‘Siemens Product PKI Infrastructure Certificates’.
- Title: Product PKI Certificate Management Service – Certificate Policy for Siemens Product PKI Infrastructure Certificates
- OID: 1.3.6.1.4.1.4329.99.1.2.1000.2
- Expiration: This version of the document is the most current one until a subsequent release. The set of all documents describing the Siemens Product PKI is referred to under the OID 1.3.6.1.4.1.4329.99.1.2. For details about the OIDs, see Chapter 7.1.6.
1.3 PKI Participants
See Central CP.
1.3.1 Certification Authorities
A graphical overview of the CA hierarchy is depicted in Figure 3: PPKI hierarchy for Infrastructure Certificates.
1.3.1.1 Root CA
See Central CP.
1.3.1.2 Intermediate CA
See Central CP.
1.3.1.3 Issuing CAs
See Central CP.
1.3.2 Registration Authorities
See Central CP.
1.3.3 Subscribers
See Central CP.
1.3.4 Relying Parties
See Central CP.
1.3.5 Other Participants
1.3.5.1 Subject (End-Entity)
See Central CP.
1.4 Certificate Usage
1.4.1 Appropriate Certificate Usage
See Central CP.
1.4.2 Prohibited Certificate Usage
See Central CP.
1.5 Policy Administration
1.5.1 Organization Administering the Document
The organization responsible for drafting, maintaining, and updating this CP is:
Siemens Aktiengesellschaft (“Siemens AG”) Foundational Technology (“FT”) Research & Predevelopment (“RPD”) Cyber Security Technology (“CST”) Otto-Hahn-Ring 6, 81739 Munich, GERMANY E-mail: contact.pki (at) siemens.com Website: https://www.siemens.com/pki
1.5.2 Contact Person
Questions about this CP may be sent to:
Siemens AG FT RPD CST Attn: Product PKI Otto-Hahn-Ring 6, 81739 Munich, GERMANY E-mail: contact.pki (at) siemens.com Certificate Problem Reports shall be sent to: contact.pki (at) siemens.com
1.5.3 Person Determining CP and CPS Suitability for the Policy
The Policy Management Authority (Tenant PMA) in section 1.5.1 determines suitability of this document and the respective CPS.
1.5.4 CPS Approval Procedures
An annual risk assessment is carried out to evaluate business requirements and determine the security requirements to be included in the certificate policy for the stated community and applicability. In addition, the CP as well as the CPS will be reviewed every year regarding consistency with the actual PKI processes and services (see also section 8). This document is accepted and approved by the Central PMA. Acceptance of the Siemens ACP process (which is part of the Siemens ISMS) constitutes acceptance of this document which therefore will not be explicitly signed. However, in case minor changes of this document will be necessary (see also 9.12.3), a new version will be published after release and official approval will be part of the next Siemens ACP process review.
1.6 Definitions and Acronyms
1.6.1 Definitions
| Term | Definition |
|---|---|
| Authority Revocation List | Certificate Revocation List containing CA certificates. |
| CA certificate | Certificate for a Certification Authority's public key. |
| Central PMA | PMA that is responsible for the management and operation of the Central Product PKI Certificate Management service. |
| Central Product PKI System | Technical components of the Product PKI Certificate Management System that are managed and operated in the Siemens Trust Center facility. |
| Certificate Policy (CP) | Compare section 1.1. |
| Certification Authority (CA) | Authority, that is entitled to certify public keys; compare section 1.3.1. |
| Distinguished Name | Sequence of data-fields uniquely identifying e.g. the issuer and the Subject within a certificate or a CRL. The format of a Distinguished Name is defined in the [X.520] standard. |
| EE certificate | See "End-Entity certificate". |
| End-Entity | Equivalent to Subject; the identity of the End-Entity is connected to the certificate and the related key-pair. See also section 1.3.3. |
| End-Entity certificate | A digital certificate is used to prove ownership of a public key and the corresponding private key. It must not be used for certifying and issuing CRLs or other certificates. |
| End-User certificate | See "End-Entity certificate". |
| HSM | Hardware Security Modul that can be used for random number generation and generation and storage of secret keys. The HSM can use the keys for digital signatures and for other PKI-applications. |
| Intermediate CA | Entity that issues and manages certificates of further Intermediate CAs or Issuing CAs and has a certificate signed by either a Root CA or by an Intermediate CA. |
| Issuing CA | Entity that issues and manages certificates of End Entities and has a certificate signed by either a Root CA or by an Intermediate CA. |
| Issuing CA System | Technical components (hardware and software) hosting Issuing and Intermediate CAs. |
| Multi-person Control | Sensitive activities typically are carried out by more than one person holding a trusted role. This is called Multi-person control. |
| Policy Management Authority | A body (of Siemens) that is responsible for setting, implementing and administering policy decisions regarding this CP and related documents and agreements in the Product PKI. |
| Product PKI | Term used in this document for the Siemens Product PKI Certificate Management Service (due to ease of readability). |
| Product PKI System | Technical components (central and local) that are necessary to manage and operate the Product PKI Certificate Management System. |
| Qualified Auditor | Auditor who has appropriate knowledge in order to evaluate and assess and confirm the requirements and corresponding implementation of measures defined in the Certificate Policy documents and the Certification Practice Statements, respectively. |
| Registration Authority (RA) | PKI-incorporated facility for participant-authentication. See also section 1.3.2. |
| Relying Party | Individual or legal entity that uses certificates; see also section 1.3.5. |
| Root CA | Entity that issues and manages certificates of Intermediate or Issuing CAs (in case there do not exist Intermediate CAs). The certificate of the Root CA is self-signed. |
| Root CA System | Technical components (hardware and software) hosting Root and (optionally) Intermediate CAs. |
| Secure Device | A component (such as a Smart Card or HSM) that substantiated to protect the private key stored in that device. All cryptographic operations using the private key are performed inside this Secure Device. |
| Siemens Product PKI Certificate Management Service | Siemens internal organization that issues and manages certificates. This organization operates the Root CA System as well as the Issuing CA systems. |
| Smart Card | Integrated circuit card including a micro-processor that can be used for random number generation and generation and storage of secret keys. A Smart Card can use the keys for the generation of digital signatures and for other PKI-applications. |
| Subject | End-Entity that uses the private End-Entity key (EE key). The End-Entity may differ from the Subscriber. |
| Subscriber | Subscriber for all certificates issued by the Product PKI is the respective Tenant as legal entity. See also section 1.3.3. |
| Tenant | Tenant can be every Siemens AG organizational unit or any other legal entity that has a contract in place that covers Product PKI services. The Tenants typically operate and maintain the Registration Authorities (e.g. within their production facilities or data center). In such a case the Tenants are responsible for RA operation and End-Entity authentication. |
| Tenant PMA | PMA that is responsible for the management and operation of the local Product PKI Certificate Management components such as RA and/or LRA as well as for identification of End-Entities. |
| Token | Transport-medium for certificates and keys. |
| Trust Center | The term "Trust Center" refers to assets and components that are centrally operated and maintained at the Trust Center location as well to the respective processes. |
| Trusted Operator | Product PKI has the overall responsibility of issuing certificates to Subjects and managing and revoking certificates. Tenants may delegate parts or these functions to the Central Product PKI Certificate Management Service or to other internal Service Providers of Siemens, which are called Trusted Operators. |
1.6.2 Acronyms
| Acronym | Meaning |
|---|---|
| ARL | Authority Revocation List |
| CA | Certification Authority |
| CISO | Chief Information Security Officer |
| CMP | Certificate Management Protocol (RFC 4210) |
| CN | Common Name |
| CP | Certificate Policy |
| CPS | Certification Practice Statement |
| CRL | Certificate Revocation List |
| DN | Distinguished Name |
| EE | End-Entity |
| FIPS | Federal Information Processing Standard |
| FQDN | Fully qualified domain name |
| HSM | Hardware Security Module |
| IEEE | Institute of Electrical and Electronics Engineers |
| IETF | Internet Engineering Task Force |
| IDevID | Initial Device Identifier (IEEE 802.1AR) |
| ISO | International Organization for Standardization |
| ISMS | Information Security Management System |
| LDevID | Locally significant Device Identifier (IEEE 802.1AR) |
| OCSP | Online Certificate Status Protocol |
| OID | Object Identifier |
| PIN | Personal Identification Number |
| PKI | Public Key Infrastructure |
| PPKI | Product PKI |
| PMA | Policy Management Authority |
| RA | Registration Authority |
| RFC | Request for Comment |
| SLA | Service Level Agreement |
| URL | Uniform Resource Locator |
| UTF8 | Unicode Transformation Format-8 |
2 Publication and Repository Responsibilities
2.1 Repositories
Tenant specific Product PKI Repositories are operated by trusted service provider(s). The repository responsibilities include:
- accurately publishing information;
- archiving certificates;
- publishing the status of certificates;
- promptness or frequency of publication; and
- security of the repository and controlling access to information published on the repository to prevent unauthorized access and tampering.
Subjects and Relying Parties have access to:
- Certificate Revocation List (CRL)
- and OCSP responder via: ppki-va.siemens.com.
2.2 Publication of Certification Information
The Tenant publishes certificate status information at ppki-va.siemens.com. The CP is published on the website specified in section 1.5.1 Organization Administering the Document.
2.3 Time or Frequency of Publication
Updates to this CP and the Central CP are published in accordance with the definitions in section 9.12 of this document.
2.4 Access Controls on Repositories
Information published in the repository can be accessed with read-only access. Administration of the published information shall be carried out only by trusted roles with adequate access control restrictions.
3 Identification and Authentication
3.1 Naming
3.1.1 Types of Names
The complete policy of specifying names and CA certificate profiles is documented for each certificate type in the respective Certificate Profile Documentation [PROF], which can be retrieved on request.
3.1.2 Need of Names to be Meaningful
3.1.2.1 CA Names
The CN must be stated as the full name of the CA.
3.1.2.2 End-Entity Names
For details see Certificate Profile Documentation [PROF].
3.1.3 Anonymity or Pseudonymity of Subscribers
3.1.3.1 CA Names
The use of pseudonyms for CA names is not permitted.
3.1.3.2 End-Entity Names
The use of pseudonyms for End Entity names is not permitted unless otherwise stated in the Tenant CP.
3.1.4 Rules for Interpreting Various Name Forms
See Central CP.
3.1.5 Uniqueness of Names
3.1.5.1 CA Names
See Central CP.
3.1.5.2 End-Entity Names
The Issuing CAs ensure during the enrollment process that uniqueness of certificates is guaranteed within the scope of the respective CA signing the certificate.
3.1.6 Recognition, Authentication, and Roles of Trademarks
See Central CP.
3.2 Initial Identity Validation
Applicants for certificates are End Entities. The applicant always acts on behalf of the Subscriber (Tenant). A certificate shall be issued to a Subject only when
- the Subject has submitted a certificate request and
- the Subject or the RA confirm private key possession.
3.2.1 Method to Prove Possession of Private Key
The key pairs are either generated by the corresponding issuing CA or by the End-Entity in case of automatic certificate update. In the latter case proof of private key possession is realized via state-of-the-art certificate management protocol, e.g. CMP.
3.2.2 Authentication of Organization Identity
The identity of the requesting organization is checked as part of the onboarding process.
3.2.3 Authentication of Individual Identity
The individual identity of the corresponding (L)RA, or End-Entity, is determined within the onboarding process.
3.2.4 Non-verified Subscriber Information
Only verified Information is included into the certificate.
3.2.5 Validation of Authority
The authority of the requester is checked as part of the onboarding process.
3.2.6 Criteria for Interoperation
No interoperation with other communities of trust is foreseen, unless otherwise stated in the Tenant CP.
3.2.7 Identification and Authentication for Re-key Requests
Not supported.
3.2.8 Identification and Authentication for Routine Re-Key
Not supported.
3.2.9 Identification and Authentication for Re-Key After Revocation
Not supported.
3.3 Identification and Authentication for Revocation Requests
The validity of revocation request shall be checked before forwarding a revocation request to the Product PKI service. Revocation of Intermediate CA and Issuing CA certificates must be authorized by the Tenant PMA. Revocation of Intermediate CA and Issuing CA certificates shall only be performed manually by Product PKI trusted employees under dual control. Revocation request of End-Entity certificates can be performed by Product PKI trusted employees (manually) and the corresponding authorized RA (automatically).
4 Certificate Lifecycle Operational Requirements
4.1 Certificate Application
4.1.1 Who can submit a certificate application?
4.1.1.1 Root and Intermediate CA
See Central CP.
4.1.1.2 Issuing CAs
See Central CP.
4.1.1.3 End-Entity Certificates
EE certificates (for examples, certificates used by RAs or by PPKI service internal components to authenticate against the central services) are generated as part of the onboarding process.
4.1.2 Enrollment Process and Responsibilities
4.1.2.1 CA Certificates
For CA certificates to be generated, following information shall be documented:
- A name for the CA in accordance with regulations in section 3.1, “Naming”, of this CP
- Date of the request
- Duration of the CA certificate, which cannot exceed the duration of the Root CA’s certificate
- Certificate profile of the new CA and
- Profiles of the End Entity certificates to be signed by that new CA, in case of an Issuing CA
4.1.2.2 End-Entity Certificate
End-Entity certificate applicants shall undergo an enrollment process consisting of:
- generating, or arranging to have generated, a key pair
- completing a certificate application and providing the required information
- either demonstrating to the respective RA or CA that the certificate applicant has possession of the private key corresponding to the public key included in the certificate application or guaranteeing by comparable measure that the certification request is originating from a legitimate End-Entity and that the End-Entity controls the private key. Certificate applications are submitted for processing, either approval or rejection, to the respective RA.
4.2 Certificate Application Processing
4.2.1 Performing identification and authentication functions
The tenant shall ensure that certificate applicants (= “Subjects”) are properly identified and authenticated.
4.2.2 Approval or Rejection of Certificate Applications
After a certificate applicant submits a certificate application, the Tenant shall approve or reject it. For EE certificates these tasks can be delegated to respective RAs. See also Central CP and section 4.2.1.
4.2.3 Time to Process Certificate Applications
See Central CP.
4.3 Certificate Issuance
4.3.1 CA Actions during Certificate Issuance
A Certificate is created and issued using secure means after the approval of a certificate application. Product PKI shall:
- check authorization of the respective RA by validating the signature of the certification request,
- generate for the Subject a Certificate based on the information in the certificate application after its validation, and
- deliver the Certificate through the respective RA.
4.3.2 Notification to Subscriber by the CA of Issuance of Certificate
The CA informs the RA whether an EE Certificate has been generated or that the certification request could not be successfully executed. The End-Entity (e.g., the operator of a RA), for which the subscriber has requested a certificate, shall be notified w.r.t. the status of certificate issuance.
4.4 Certificate Acceptance
4.4.1 Conduct constituting certificate acceptance
The Subjects shall securely obtain the Certificate through the respective RA.
4.4.2 Publication of the certificate by the CA
No stipulation.
4.4.3 Notification of Certificate issuance by the CA to other entities
No stipulation.
4.5 Key Pair and Certificate Usage
The Issuing CA private key is only used for:
- Issuance of certificates to End-Entities
- Issuance of Issuing CA’s CRLs
- Issuance of CRL signer certificates and OCSP signer certificates
- Signing of CMP messages sent to the RA
See also Central CP
4.5.1 Subject Private Key and Certificate Usage
See Central CP.
4.5.2 Relying Party Public Key and Certificate Usage
See Central CP.
4.6 Certificate Renewal
Certificate renewal is the issuance of a new certificate to an entity without changing the public key or any other information in the certificate. Not supported.
4.6.1 Circumstance for Certificate Renewal
No stipulation.
4.6.2 Who may request renewal?
No stipulation.
4.6.3 Processing Certificate Renewal Request
No stipulation.
4.6.4 Notification of new Certificate Issuance to Subscriber
No stipulation.
4.6.5 Conduct Constituting Acceptance of a Renewal Certificate
No stipulation.
4.6.6 Publication of the Renewal Certificate by the CA
No stipulation.
4.6.7 Notification of Certificate Issuance by the CA to other Entities
No stipulation.
4.7 Certificate Re-key
“Re-key” addresses the generating of a new Key Pair and applying for the issuance of a new certificate and replacing the existing Key Pair.
4.7.1 Circumstances for Certificate Re-key
See Central CP.
4.7.2 Who may request certification of a new Public Key?
4.7.2.1 Re-keying of an Issuing CA certificate
See Central CP.
4.7.2.2 Re-keying of End-Entity certificates
For re-keying of EE certificates, the same requirements apply as for certificate Issuance (see section 4.3). No previously validated information shall be reused.
4.7.3 Processing Certificate Re-keying Requests
See section 4.3.1
4.7.4 Notification of new Certificate Issuance to Subscriber
See section 4.3.2
4.7.5 Conduct Constituting Acceptance of a Re-keyed Certificate
See section 4.4.1
4.7.6 Publication of the Re-keyed Certificate by the CA
See section 4.4.2
4.7.7 Notification of Certificate Issuance by the CA to other Entities
See section 4.4.3.
4.8 Certificate Modification
Certificate modification means that the keys of a certificate remain unchanged, but more certificate information than for a certificate renewal is changed. Not supported.
4.8.1 Circumstance for Certificate Modification
No stipulation.
4.8.2 Who may request Certificate modification?
No stipulation.
4.8.3 Processing Certificate Modification Requests
No stipulation.
4.8.4 Notification of new Certificate Issuance to Subscriber
No stipulation.
4.8.5 Conduct Constituting Acceptance of Modified Certificate
No stipulation.
4.8.6 Publication of the Modified Certificate by the CA
No stipulation.
4.8.7 Notification of Certificate Issuance by the CA to Other Entities
No stipulation.
4.9 Certificate Revocation and Suspension
4.9.1 Circumstances for Revocation
See Central CP.
4.9.2 Who can request revocation?
RA owners can request revocation of the EE certificates that have been issued for their RA.
4.9.3 Procedure for Revocation Request
See also central CP. See also section 3.4.
4.9.4 Revocation Request Grace Period
See Central CP.
4.9.5 Time within which CA must Process the Revocation Request
See Central CP.
4.9.6 Revocation Checking Requirement for Relying Parties
Relying Parties shall check the status of certificates on which they wish to rely by consulting the most recent CRL or using another applicable method.
4.9.7 CRL Issuance Frequency
ARLs are regularly issued every 6 month or in exceptional cases when a specific CA certificate needs to be revoked. CRLs are regularly issued once per day or in exceptional cases when a specific EE certificate needs to be revoked.
4.9.8 Maximum Latency for CRLs
CRLs shall be posted to the repository within a reasonable time after generation.
4.9.9 On-line Revocation/Status Checking Availability
Not supported.
4.9.10 On-line Revocation Checking Requirements
No stipulation.
4.9.11 Other Forms of Revocation Advertisements Available
No stipulation.
4.9.12 Special Requirements for Private Key Compromise
In case of a CA certificate compromise the RA owners shall be informed. If the RA operator has a reason to believe that there has been a compromise of an EE private key, then it shall notify the respective Issuing CA to take appropriate action, including request for revocation. See also central CP for central service aspects.
4.9.13 Circumstances for Suspension
Not supported.
4.9.14 Who can request suspension?
No stipulation.
4.9.15 Procedure for suspension request
No stipulation.
4.9.16 Limits on suspension period
No stipulation.
4.10 Certificate Status Services
4.10.1 Operational Characteristics
See section 4.9.
4.10.2 Service Availability
The service to retrieve CRLs shall be available twenty-four (24) hours a day, seven (7) days a week, except in case of Force Majeure Events (CP section 9.16.5).
4.10.3 Optional Features
No stipulation.
4.11 End of Subscription
See Central CP.
4.12 Key Escrow and Recovery
Not supported.
4.12.1 Key Escrow and Recovery Policy and Practices
No stipulation.
4.12.2 Session Key Encapsulation and Recovery Policy and Practices
No stipulation.
5 Management, Operational, and Physical Controls
As this tenant for providing key material and certificates to securely connect RAs with the Central Product PKI service is operated as part of the Central PPKI service, all relevant requirements are set forth in the Central CP [CP].
5.1 Physical Security Controls
5.1.1 Site Location and Construction
See central CP.
5.1.2 Physical Access
See central CP.
5.1.3 Power and Air Conditioning
See central CP.
5.1.4 Water Exposure
See central CP.
5.1.5 Fire Prevention and Protection
See central CP.
5.1.6 Media Storage
See central CP.
5.1.7 Waste Disposal
See central CP.
5.1.8 Off-site Backup
See central CP.
5.2 Procedural Controls
5.2.1 Trusted Roles
See central CP.
5.2.2 Numbers of Persons Required per Task
See central CP.
5.2.3 Identification and Authentication for Each Role
See central CP.
5.2.4 Roles Requiring Separation of Duties
See central CP.
5.3 Personnel Controls
5.3.1 Qualifications, Experience and Clearance Requirements
See central CP.
5.3.2 Background Check Procedures
See central CP.
5.3.3 Training Requirements
See central CP.
5.3.4 Retraining Frequency and Requirements
See central CP.
5.3.5 Job Rotation Frequency and Sequence
See central CP.
5.3.6 Sanctions for Unauthorized Actions
See Central CP.
5.3.7 Independent Contractor Requirements
See Central CP.
5.3.8 Documents Supplied to Personnel
See Central CP.
5.4 Audit Logging Procedures
5.4.1 Types of Events Recorded
See central CP.
5.4.2 Frequency of Processing Log
See Central CP.
5.4.3 Retention Period for Audit Log
See central CP.
5.4.4 Protection of Audit Log
See central CP.
5.4.5 Audit Log Backup Procedures
See central CP.
5.4.6 Audit Collection System (Internal vs. External)
See central CP.
5.4.7 Notification to Event-Causing Subject
See Central CP.
5.4.8 Vulnerability Assessments
See central CP.
5.5 Records Archival
5.5.1 Types of Records Archived
See central CP.
5.5.2 Retention Period for Archived Audit Logging Information
See central CP.
5.5.3 Protection of Archive
See central CP.
5.5.4 Archive Backup Procedures
See central CP.
5.5.5 Requirements for Time-Stamping of Record
See Central CP.
5.5.6 Archive Collection System (internal or external)
See central CP.
5.5.7 Procedures to Obtain and Verify Archived Information
See Central CP.
5.6 Key Changeover
In the event of a CA key changeover, the new CA public key shall be published with a suitable interval between certificate expiry date and the last certificate signed to prevent service interruption.
5.7 Compromise and Disaster Recovery
5.7.1 Incident and Compromise Handling Procedures
See Central CP.
5.7.2 Corruption of Computing Resources, Software, and/or Data
See Central CP.
5.7.3 Entity Private Key Compromise Procedures
See Central CP.
5.7.4 Business Continuity Capabilities After a Disaster
See Central CP.
5.8 CA or RA Termination
See central CP.
6 Technical Security Controls
6.1 Key Pair Generation and Installation
6.1.1 Key Pair Generation
For generation of Root CA keys and Issuing CA keys see Central CP [CCP]. EE keys (for TLS and CMP communication) can either be generated centrally by the PKI software or by the respective subject (RA or LRA).
6.1.2 Private Key Delivery to Subscriber
In case a RA requests a Key Pair as subscriber from the central service, the corresponding private key shall be delivered securely using technical and/or organizational means. See also Central CP [CCP] for central service aspects.
6.1.3 Public Key Delivery to Certificate Issuer
In case of centrally generated key pairs no public key needs to be delivered to the CA. In case of automated rekeying the public key and the certification request shall be transmitted securely to the CA.
6.1.4 CA Public Key Delivery to Relying Parties
Relying party is only the central PPKI service. The delivery of CA public keys is performed as part of the initial key event (set-up of issuing CA). See also Central CP [CCP].
6.1.5 Key Sizes
Minimum requirements for key sizes and algorithms are defined in accordance with [BSI], [ECRYPT], and [NIST].
6.1.6 Public Key Parameters Generation and Quality Checking
CAs and subscribers shall generate Key Pairs using secure algorithms and parameters based on state-of-the-art cryptography and industry standards. These Key Pairs shall be generated in Hardware Security Modules certified according to FIPS 140-2 level 3, hence guaranteeing sufficient quality of the parameters used and the overall Key Pair generation procedure.
6.1.7 Key Usage Purposes (as per X.509 v3 Key Usage Field)
See Central CP.
6.2 Private Key Protection and Cryptographic Module Engineering Controls
6.2.1 Cryptographic Module Standards and Controls
It is strongly recommended that end-entities securely store the private key (e.g. within a TPM if possible). See also central CP for central service aspects.
6.2.2 Private Key (n out of m) Multi-person Control
4 eyes principle is applied for private keys of end entities (see 6.1.2 Private Key Delivery to Subscriber). See also central CP for central service aspects.
6.2.3 Private Key Escrow
Not supported.
6.2.4 Private Key Backup
See Central CP.
6.2.5 Private Key Archival
No stipulation.
6.2.6 Private Key Transfer into or from a Cryptographic Module
Not supported for End-Entity keys. See also central CP for central service aspects.
6.2.7 Private Key Storage on Cryptographic Module
End-Entity keys shall be stored in a security module if technically feasible. See also central CP for central service aspects.
6.2.8 Method of Activating Private Key
End-Entity private keys are automatically active after generation. See also central CP for central service aspects.
6.2.9 Method of Deactivating Private Key
Deactivating Private Keys is not supported.
6.2.10 Method of Destroying Private Key
End-Entity private keys shall be deleted in case of resetting the RA. See also central CP for central service aspects.
6.2.11 Cryptographic Module Rating
See section 6.2.1.
6.3 Other Aspects of Key Pair Management
6.3.1 Public key archival
Public key and related certificate shall be archived in accordance with Section 5.5.
6.3.2 Certificate operational periods and key pair usage periods
The respective maximum validity periods for keys are:
| Certified Entity | Validity Period |
|---|---|
| PPKI Infrastructure Root CA | Up to two years |
| PPKI Infrastructure Issuing CA | Up to two years |
| CMP certificate | Up to one year |
| TLS certificate | Up to one year |
Table 1: Maximum validity periods
See also central CP.
6.4 Activation Data
6.4.1 Activation Data Generation and Installation
Passphrase for PKCS#12 container is defined during the onboarding and securely delivered to the Tenant. See also central CP for central service aspects.
6.4.2 Activation Data Protection
See Central CP.
6.4.3 Other Aspects of Activation Data
See Central CP.
6.5 Computer Security Controls
6.5.1 Specific Computer Security Technical Requirements
Specific computer security requirements for RAs are defined in [ISMS]. See also central CP for central service aspects.
6.5.2 Computer Security Rating
No stipulation.
6.6 Life Cycle Security Controls
6.6.1 System Development Controls
See Central CP.
6.6.2 Security Management Controls
RA security management controls shall follow regulations equivalent to Siemens ISMS [ISMS]. See also central CP for central service aspects.
6.6.3 Life Cycle Security Controls
See Central CP.
6.7 Network Security Controls
The (L)RA network security controls shall follow regulations equivalent to Siemens ISMS [ISMS]. See also central CP for central service aspects.
6.8 Time Stamp Process
See Central CP.
7 Certificate, CRL, and OCSP Profiles
7.1 Certificate Profile
Details of the tenant specific certificate profile can be found in [PROF]. See also central CP.
7.1.1 Version Number(s)
See Central CP.
7.1.2 Certificate Extensions
See Central CP.
7.1.3 Algorithm Object Identifiers
Product PKI shall issue Subject certificates using only algorithms that are compatible with section 6.1.5.
7.1.4 Name Forms
Product PKI shall only issue Subject certificates whose Issuer and Subject information is consistent with the Tenant CP.
7.1.5 Name Constraints
No stipulation.
7.1.6 Certificate Policy Object Identifier
If OIDs are present the following applies. Digital certificates use Object Identifiers (OIDs) to uniquely identify objects like data structures, algorithm definitions, or key usages. OIDs are structured in a hierarchical manner. They are not only used by digital certificates but in a variety of protocols.
7.1.6.1 Definition of OIDs
Object Identifiers are strings of numbers with dots as separators. They are allocated in a hierarchical manner, so that, each number represents an authority. For instance, the authority for "1.2.3" is the only one that can say what "1.2.3.4" means. They are used in a variety of frameworks and protocols. The formal definition of OIDs comes from ITU-T X.680 (ASN.1). Each position in an OID sequence identifies a node in a tree structure. The ASN.1 standard assigns each node a name and meaning. E.g., the positions in the OID 1.2.840.10045.4.3.4 represent the following tree nodes:
iso(1).member-body(2).us(840).ansi-x962(10045).signatures(4).ecdsa-with-SHA2(3).ecdsa-with-SHA512(4)
This OID string as defined by ANSI is the identifier for the Elliptic Curve Digital Signature Algorithm (ECDSA) coupled with the hash algorithm SHA-512.
7.1.6.2 Enterprise numbers
The Internet Assigned Numbers Authority (IANA) is a department of the Internet Corporation for Assigned Names and Numbers (ICANN) responsible for coordinating some of the key elements that keep the Internet running smoothly. Whilst the Internet is renowned for being a worldwide network free from central coordination, there is a technical need for some key parts of the Internet to be globally coordinated and this coordination role is undertaken by IANA. Specifically, IANA allocates and maintains unique codes and numbering systems that are used in the technical standards (frameworks and protocols) that drive the Internet. Private enterprise numbers (PENs) are a subset of Object Identifiers, starting with the prefix 1.3.6.1.4.1 and representing the following path in the ASN.1 tree:
iso(1).org(3).dod(6).internet(1).private(4).enterprise(1).
A company or organization may apply for a private enterprise number to use these numbering systems without conflicting with other companies and users. This number is assigned by the IANA and is appended to the OID string above.
7.1.6.3 Siemens OIDs
The Enterprise Number of Siemens AG is 4329. So, all OIDs starting with 1.3.6.1.4.1.4329 are Siemens specific. The position behind the 4329 identifies Siemens organizations, services, and applications. The top-level OIDs below 4329 are centrally managed, currently by T TIM RSQ TMR, Ms. Uschi Obermeier, GID:Z0004FTO.
7.1.6.4 Product PKI CP/CPS Document OIDs
The OID 1.3.6.1.4.1.4329.99.1.2 is reserved in the Siemens MIB for the documents related to Siemens Certificate Policies of Siemens Product PKI. Hierarchically subordinated under this OID the Siemens PKI services manage an OID sub-tree to identify objects relevant for its operation like organizational units and document versions. Currently this sub-tree consists of the nodes x indicating the Product PKI tenant, y indicating the major version of the document (1.3.6.1.4.1.4329.99.1.2.x.y).
7.1.6.4.1 Tenant
The first position in the Siemens Product PKI OID sub-tree identifies the tenant of the Siemens Product PKI service. A tenant is a part of the Siemens Product PKI system which is provided to one organization (usually a Siemens BU or factory) acting as customer of the Siemens Product PKI service. The Siemens Product PKI service hosts a dedicated set of Root and/or Issuing CAs for each tenant. The OID 1.3.6.1.4.1.4329.99.1.2.1 identifies the first tenant of the Siemens Product PKI service. This number is incremented for each new tenant. All objects related to this tenant start with this sequence. The number 1000 identifies a special tenant – the Siemens Product PKI service itself. All objects not related to a dedicated tenant but to the central Siemens Product PKI service are identified by OIDs starting with 1.3.6.1.4.1.4329.38.1000.
7.1.6.4.2 Document version number
The version number of the Certificate Policy (CP) is identified by the next position. Changes, which will materially change the acceptability of certificates for specific purposes, will lead to a corresponding change in the CP OID. Changes, which will not materially reduce the assurance that the CP or its implementation provides and will be judged by the Policy Management Authority to have an insignificant effect on the acceptability of certificates, do not require a change in the CP OID.
7.1.6.5 Product PKI certificate type and key store OIDs
The OID 1.3.6.1.4.1.4329.38 is reserved in the Siemens MIB for the Product PKI services. Hierarchically subordinated under this OID the Product PKI services manage an OID sub-tree to identify objects relevant for its operation like documents, organizational units, services, and certificate types. Currently this sub-tree consists of the nodes x indicating the Product PKI tenant, y indicating the certificate type, and z indicating the type of key storage (1.3.6.1.4.1.4329.38.x.y.z).
7.1.6.5.1 Tenant
The first position in the Siemens Product PKI OID sub-tree identifies the tenant of the Siemens Product PKI service. A tenant is a part of the Siemens Product PKI system which is provided to one organization (usually a Siemens BU or factory) acting as customer of the Siemens Product PKI service. The Siemens Product PKI service hosts a dedicated set of Root and/or Issuing CAs for each tenant. The OID 1.3.6.1.4.1.4329.38.1 identifies the first tenant of the Siemens Product PKI service. This number is incremented for each new tenant. All objects related to this tenant start with this sequence. The number 1000 identifies a special tenant – the Siemens Product PKI service itself. All objects not related to a dedicated tenant but to the central Siemens Product PKI service are identified by OIDs starting with 1.3.6.1.4.1.4329.38.1000.
7.1.6.5.2 Certificate Type
The type of certificate is identified by the next position. The following certificate categories are defined:
- Manufacturer Certificates (OID 1.3.6.1.4.1.4329.38.x.1)
These certificates identify Siemens hardware devices during their whole existence. Usually, the certificates’ validity conforms to the expected lifetime of the devices. Renewal of these certificates is foreseeable only in exceptional cases, but revocation and the publication of appropriate status information is required by the manufacturer.
- Operational Certificates (OID 1.3.6.1.4.1.4329.38.x.2)
This category includes all certificates issued by a tenant for usage by devices, applications, or persons (e.g. service technicians) during regular operation at the end customer site. The applications may be running directly on the devices or on arbitrary hardware (e.g., PCs or virtual machines). Examples are certificates for TLS session establishment (TLS client and/or server certificates), VPN, or for signing of log data. Operational certificates have a limited lifetime and need to be managed after issuance. Also, revocation and the publication of appropriate status information may be required for these certificates.
- Infrastructure Certificates (OID 1.3.6.1.4.1.4329.38.x.3)
These are the certificates used by the Siemens Product PKI service to secure its own operational processes. Infrastructure Certificates are used, e.g., for TLS based client-server-authentication between the single components of the Siemens Product PKI service (like LRA and CMP Gateway) or for the signing of CMP messages by these components. Infrastructure Certificates have to be renewed regularly and may be revoked on demand. Certificate status information must be available via OCSP and CRLs.
- Signature Certificates for Manufacturer Data (OID 1.3.6.1.4.1.4329.38.x.4)
These certificates identify Siemens code, licenses, device specific configurations, product information, etc. by digitally signing such data. The validity of these certificates conforms to the expected lifetime of devices, similar to the Manufacturer Certificates. The actual usage time may be much shorter so frequent certificate updates may be required. Furthermore, revocation and publication of appropriate status information by the manufacturer are required.
- Signature Certificates for Third Party Usage (OID 1.3.6.1.4.1.4329.38.x.5)
These certificates are similar to Signature Certificates used by the manufacturer, but given to Siemens’ partners (e.g., system integrators, value-add partners, OEM manufacturers) to identify their data (code, device specific configurations, etc.) by digitally signing. The validity of these certificates may also conform to the expected lifetime of related devices. The actual usage time may be much shorter so frequent certificate updates may be required. Furthermore, revocation and publication of appropriate status information by the manufacturer (who gives the certificates to partners) are required.
7.1.6.5.3 Key Store
The final position in the OID string denotes the type of key store:
- Secure Device - internal generation (OID 1.3.6.1.4.1.4329.38.x.y.1)
This OID indicates that the private key corresponding to the public key in the certificate is created and stored inside a secure element that applies hardware-based security mechanisms to prevent reading/extraction or misusing the private key. The private key only exists inside the secure element. Examples for such secure elements are embedded security controllers, smart cards or hardware security modules.
- Software Key Store (OID 1.3.6.1.4.1.4329.38.x.y.2)
The corresponding private key is stored in a software based Personal Security Environment. This is usually an encrypted file (e.g., according to the PKCS#12 standard).
- Secure Device - external generation (OID 1.3.6.1.4.1.4329.38.x.y.3)
This OID indicates that the private key is created outside but imported into and stored inside a secure element that applies hardware-based security mechanisms to prevent reading/extraction or misusing the private key. The private key may exist also outside the secure element. The information on the key store is important for certificate users to determine the trust level of the certificate. Secure Device based key stores should offer a much higher level of security compared to software-based key stores. Subject certificates issued under this CP shall assert one or more of the Certificate Policy OIDs listed in section 1.2 of Certificate Policy. Issuing CA certificate shall either contain the policy OIDs of all policies under which it issues certificates or the anyPolicy OID (2.5.29.32.0).
7.1.7 Usage of Policy Constraints Extension
No stipulation.
7.1.8 Policy Qualifiers Syntax and Semantics
No stipulation.
7.1.9 Processing Semantics for the Critical Certificate Policies Extension
Critical Certificate Policy extension shall conform to IETF RFC 5280 [RFC5280].
7.2 CRL Profile
7.2.1 Version number(s)
See Central CP.
7.2.2 CRL and CRL entry extensions
See Central CP.
7.3 OCSP Profile
7.3.1 Version Number(s)
See Central CP.
7.3.2 OCSP Extension
See Central CP.
8 Compliance Audit and Other Assessment
8.1 Frequency or Circumstances of Assessment
Compliance to this CP and the relevant CPSs shall be checked on a yearly basis. In addition, a bi-annual asset classification of the PKI components takes place. The asset classification is performed in accordance with the Siemens Enterprise Risk Management Process [ERM]. A possible outcome of either the audit or the asset classification is the adaption of the implemented security mechanisms and controls, which may result in changes in CP and CPSs.
8.2 Identity / Qualifications of Assessor
Compliance audits shall be performed by a qualified auditor. See also central CP for central service aspects.
8.3 Assessor’s Relationship to Assessed Entity
The assessor shall be organizationally independent from the assessed entity’s operational authority. See also central CP for central service aspects.
8.4 Topics Covered by Assessment
See Central CP.
8.5 Actions Taken as a Result of Deficiency
If a compliance audit or other assessments show deficiencies of the assessed entity, a determination of actions to be taken shall be made. This determination is made by Tenant PMA with input from the auditor/assessor. Tenant PMA is responsible for developing and implementing a corrective action plan. If Tenant PMA determines that such deficiencies pose an immediate threat to the security or integrity of the Product PKI or the respective Tenant, a corrective action plan shall be developed in accordance with the incident response procedures described in section 5.7.1 within thirty (30) days and implemented within a commercially reasonable period of time, and a re-assessment is to be performed within thirty (30) days after completion of the corrective action. For less serious deficiencies, Tenant PMA shall evaluate the significance of such issues and determine the appropriate response. Possible actions taken include but are not limited to:
- 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
8.6 Communication of Results
An Audit Compliance Report, including identification of corrective measures taken or being taken by the component, shall be provided to the Tenant PMA.
9 Other Business and Legal Matters
All business and legal matters will be regulated within specific contracts if necessary.
9.1 Fees
9.1.1 Certificate Issuance or Renewal fees
No stipulation.
9.1.2 Certificate Access fees
No stipulation.
9.1.3 Revocation or Status Information Access fees
No stipulation.
9.1.4 Fees for other Services
No stipulation.
9.1.5 Refund Policy
No stipulation.
9.2 Financial Responsibility
No stipulation.
9.2.1 Insurance Coverage
No stipulation.
9.2.2 Other Assets
No stipulation.
9.2.3 Insurance or Warranty Coverage for End-Entities
No stipulation.
9.3 Confidentiality of Business Information
9.3.1 Scope of Confidential Information
No stipulation.
9.3.2 Information not within the Scope of Confidential Information
No stipulation.
9.3.3 Responsibility to Protect Confidential Information
No stipulation.
9.4 Privacy of Personal Information
9.4.1 Privacy plan
No stipulation.
9.4.2 Information treated as private
No stipulation.
9.4.3 Information not deemed private
No stipulation.
9.4.4 Responsibility to protect private information
No stipulation.
9.4.5 Notice and consent to use private information
No stipulation.
9.4.6 Disclosure pursuant to judicial or administrative process
No stipulation.
9.4.7 Other information disclosure circumstances
No stipulation.
9.5 Intellectual Property Rights
No stipulation.
9.5.1 Intellectual Property Rights in Certificates and Revocation Information
No stipulation.
9.5.2 Intellectual Property Rights in CP
No stipulation.
9.5.3 Intellectual Property Rights in Names
No stipulation.
9.5.4 Property rights of Certificate Owners
No stipulation.
9.6 Representations and Warranties
9.6.1 CA representations and warranties
No stipulation.
9.6.2 RA representations and warranties
No stipulation.
9.6.3 Subscriber representations and warranties
No stipulation.
9.6.4 Relying party representations and warranties
No stipulation.
9.6.5 Representations and warranties of other participants
No stipulation.
9.7 Disclaimers of Warranties
No stipulation.
9.8 Limitations of Liability
No stipulation.
9.9 Indemnities
No stipulation.
9.10 Term and Termination
9.10.1 Term
No stipulation.
9.10.2 Termination
See Central CP.
9.10.3 Effect of Termination and Survival
No stipulation.
9.11 Individual Notices and Communication with Participants
No stipulation.
9.12 Amendments
9.12.1 Procedure for Amendment
In the case of CP amendments, change procedures may include:
- a notification mechanism to provide notice of proposed amendments to affected Product PKI Participants
- 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
9.12.2 Notification Mechanism and Period
A modification or amendment of the CP/CPS leads to a new version of the CP/CPS. The new version of the CP/CPS will be published after its release on the website stated in section 1.5.1.
9.12.3 Circumstances under which OID must be changed
Changes, which will not materially reduce the assurance that the CP or its implementation provides and will be judged by the Policy Management Authority (CP section 1.5) to have an insignificant effect on the acceptability of certificates, do not require a change in the CP OID. Changes, which will materially change the acceptability of certificates for specific purposes, may require corresponding changes to the CP OID.
9.13 Dispute Resolution Provisions
No stipulation.
9.14 Governing Law
No stipulation.
9.15 Compliance with Applicable Law
No stipulation.
9.16 Miscellaneous Provisions
No stipulation.
9.16.1 Entire Agreement
No stipulation.
9.16.2 Assignment
No stipulation.
9.16.3 Severability
No stipulation.
9.16.4 Enforcement (attorneys' fees and waiver of rights)
No stipulation.
9.16.5 Force Majeure
Siemens shall be not held liable for violations of this CP due to causes that are reasonably beyond its control, including but not limited to, an event of Force Majeure, act of the authority, failure of equipment, failure of telecommunications lines, failure of internet access or any unforeseeable events.
9.17 Other Provisions
9.17.1 Order of Precedence of CP
This CP provides baseline requirements that are applicable to all CAs operated in the name of the Tenant. In the event of a conflict between this CP and any other documents, the following documents shall be given precedence with the same order of the list:
For the scope of applicability for the Product PKI as defined in section 1.1:
- Product PKI Central CP
- Tenant CP that is applicable to a Tenant operated by the Product PKI [this document]
- Documentation executed or expressly authorized by respective PMA
For the scope of applicability for the Tenant specific parts (in particular (L)RA operation and End-Entity authentication) as defined in section 1.1:
- Tenant CP that is applicable to a Tenant operated by the Product PKI [this document]
- Product PKI Central CP
- Documentation executed or expressly authorized by respective PMA
10 References
In case of legitimate interest, Siemens internal regulations and guidelines as well as other internal documents can be retrieved on request.
[ACP] Asset Classification & Protection; https://intranet.siemens.com/acp
[CCP] Siemens Product PKI Certificate Management Service – Central Certificate Policy; Jan. 14, 2022 , Version 1.8 , www.siemens.com/pki
[CCPS] Siemens Product PKI Certificate Management Service – Central Certification Practice Statement; Jan. 14, 2022, Version 1.2 , www.siemens.com/pki
[ECRYPT] ECRYPT-CSA; Algorithms, Key Size and Protocols Report; February 2018; https://www.ecrypt.eu.org/csa/documents/D5.4-FinalAlgKeySizeProt.pdf
[ERM] Siemens Enterprise Risk Management; “Enterprise Risk Management – Integrated Framework”; https://intranet.for.siemens.com/cms/054/en/about/org/Pages/cf-a-erm-org.aspx and https://intranet.for.siemens.com/cms/080/de/processes/office/Pages/ric-ch-erm.aspx
[ETSI 401] ETSI EN 319 401; Electronic Signatures and Infrastructures (ESI); General Policy Requirements for Trust Service Providers; August 2017
[ETSI 411] ETSI EN 319 411-1; Electronic Signatures and Infrastructures (ESI); Policy and security requirements for Trust Service Providers issuing certificates; Part 1: General requirements; August 2017
[FIPS] National Institute of Standards and Technology; SECURITY REQUIREMENTS FOR CRYPTOGRAPHIC MODULES; May 2001; https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf
[IEEE802.1AR] IEEE 802.1AR; IEEE Standard for Local and Metropolitan Area Networks - Secure Device Identity; June 2018; https://standards.ieee.org/standard/802_1AR-2018.html
[IHP] The Siemens Incident Handling process as part of the ISMS; https://www.cert.siemens.com/incident-response/process/
[ISMS] SFeRA - Security Framework and Regulations Application; https://webapps.siemens.com/sfera
[ISO27001] ISO/IEC 27001; Information technology — Security techniques — Information security management systems — Requirements; October 2013
[NIST] Recommendation for Key Management, Special Publication 800-57 Part 1 Rev. 5 (Draft), NIST, 10/2019; https://www.nist.gov/news-events/news/2019/10/recommendation-key-management-part-1-general-draft-nist-sp-800-57-part-1
[PROF] Certificate Profile Naming Convention for Infrastructure Certificates, https://wiki.ct.siemens.de/display/ProductPKI/PPKI+Naming+Conventions
[RFC2119] IETF; RFC 2119; Key words for use in RFCs to Indicate Requirement Levels; March 1997.
[RFC3647] IETF; RFC 3647; Internet X.509 Public Key Infrastructure - Certificate Policy and Certification Practices Framework; November 2003.
[RFC5280] IETF; RFC 5280; Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile; May 2008; https://tools.ietf.org/html/rfc5280
[TÜV] TÜV IT; Sichere Infrastrukturen für IT-Systeme – Trusted Site Infrastructure; Version 4.0; https://www.tuvit.de/fileadmin/user_upload/TUEViT_TSI_V4_0.pdf
[X.520] ITU-T; X520 Information technology – Open Systems Interconnection – The Directory: Selected attribute types; 2012; https://www.itu.int/rec/T-REC-X.520/en