SignCertificate

CertificateManagement CS->CSMS OCPP 2.0.1

Sent by the Charging Station to request the CSMS to sign a certificate signing request (CSR) for the station's TLS certificate or V2G certificate.

Quick Reference

Required Fields

csr string(5500)

The PEM-encoded Certificate Signing Request

certificateType CertificateSigningUseEnumType

Type of certificate: ChargingStationCertificate or V2GCertificate

Example Payload

{
  "csr": "-----BEGIN CERTIFICATE REQUEST-----\nMIIBmTCCAQICAQAwWTELMAkGA1UEBhMCREUx...\n-----END CERTIFICATE REQUEST-----",
  "certificateType": "ChargingStationCertificate"
}

Example Full Frame

[
  2,
  "msg-001",
  "SignCertificate",
  {
    "csr": "-----BEGIN CERTIFICATE REQUEST-----\nMIIBmTCCAQICAQAwWTELMAkGA1UEBhMCREUx...\n-----END CERTIFICATE REQUEST-----",
    "certificateType": "ChargingStationCertificate"
  }
]

Format: [MessageType, MessageId, Action, Payload]

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Overview

SignCertificate is part of OCPP 2.0.1’s built-in security. The Charging Station generates a CSR and sends it to the CSMS, which forwards it to a CA (Certificate Authority). The signed certificate is returned via CertificateSigned.

When to Send

During initial provisioning to get the station’s TLS certificate
When the TLS certificate is about to expire
To obtain a V2G certificate for ISO 15118 Plug & Charge

Expected Response

status: Accepted or Rejected

The actual signed certificate arrives via CertificateSigned.

Usage Notes

ChargingStationCertificate: Used for the OCPP WebSocket TLS connection
V2GCertificate: Used for ISO 15118 Vehicle-to-Grid communication
The CSMS may forward the CSR to an external CA — delivery of the signed certificate may be delayed

Testing Tips

Generate a real CSR with OpenSSL and test the full signing flow
Verify the signed certificate arrives via CertificateSigned with the correct type

Common Errors

`PropertyConstraintViolation`

Cause: csr exceeds 5500 characters

Solution: Keep the PEM-encoded CSR under 5500 characters

`TypeConstraintViolation`

Cause: certificateType uses an unsupported value

Solution: Use ChargingStationCertificate or V2GCertificate