How To Fix TRUST203 - Certificate for this key pair is missing

SAP Error Message - Details

• Message type: E = Error

• Message class: TRUST - Certificate Management

• Message number: 203

• Message text: Certificate for this key pair is missing

What causes this issue?

You attempted to import a private key into a PSE. You still need to
import one or more public key certificates.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

If the traffic light is red, you need to select and import one or more
additional public key certificates, until the certificate chain is
completed with a self-signed certificate.
To select the certificate, choose the <ZK>Import Certificate</> button.
Select the appropriate file and import it. You can perform the import
repeatedly, until the certificate chain is complete.
&NOTE&
A PSE always contains only one private key, whereas, for example, a
filein PKCS#12 format (*.p12) can have multiple private keys. If the
PKCS#12file contains multiple private keys, you need to select a key. To
do this, open the selection list in the <ZK>Private Key</> field, and
checkwhether additional private keys exist. Select the desired key in
the selection list, and import it.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message TRUST203 - Certificate for this key pair is missing ?

  The SAP error message TRUST203 indicates that a certificate for a specific key pair is missing in the system's trust store. This error typically arises in scenarios involving secure communications, such as when using SSL/TLS for secure connections or when dealing with digital signatures.
  Cause:
  The error occurs when:
  
  A key pair (public/private key) has been generated, but the corresponding certificate has not been created or imported into the system.
  The certificate might have expired or been deleted.
  The system is unable to find the certificate associated with the key pair in the trust store.
  
  Solution:
  To resolve the TRUST203 error, you can follow these steps:
  
  
  Check Key Pair:
  
  Go to transaction code STRUST in the SAP GUI.
  Navigate to the appropriate key storage (e.g., "SSL Client (Standard)" or "SSL Server (Standard)").
  Verify if the key pair exists and check its details.
  
  
  
  Create/Import Certificate:
  
  If the certificate is missing, you can create a new one or import an existing certificate.
  To create a new certificate:
  
  In the STRUST transaction, select the key pair and choose the option to create a certificate request.
  Submit the request to a Certificate Authority (CA) to obtain a signed certificate.
  
  
  To import a certificate:
  
  Obtain the certificate from the CA and use the import function in STRUST to add it to the key pair.
  
  
  
  
  
  Check Certificate Validity:
  
  Ensure that the certificate is valid and not expired. If it is expired, you will need to renew it.
  
  
  
  Assign Certificate to Key Pair:
  
  After importing or creating the certificate, ensure it is correctly assigned to the corresponding key pair.
  
  
  
  Transport Changes:
  
  If you are working in a development environment, ensure that any changes made (like importing a new certificate) are transported to the production environment.
  
  
  
  Restart Services:
  
  After making changes, it may be necessary to restart the relevant SAP services or the entire SAP system to ensure that the changes take effect.
  
  
  
  Related Information:
  
  
  Transaction Codes:
  
  STRUST: Manage SSL certificates and key pairs.
  STRUSTSSO2: Manage Single Sign-On (SSO) certificates.
  
  
  
  Documentation:
  
  Refer to SAP Help documentation for detailed steps on managing SSL certificates and key pairs.
  
  
  
  Security Considerations:
  
  Always ensure that you are following best practices for security when handling certificates and private keys, including using strong passwords and secure storage.
  
  
  
  By following these steps, you should be able to resolve the TRUST203 error and ensure that your SAP system can establish secure connections as needed.