3538749 - [Cloud Integration] Unauthorized error, as Subject and issuer of the provided certificate "is not contained in the accepted subjectAndIssuers list of the integration flow"

While calling Cloud Integration endpoint with Client Certificate Authentication, HTTP 403 Unauthorized error might occur.
In Monitor -> System Log Files -> trace (or ljs trace), below error could be identified:

Unauthorized. Subject and issuer (subject: cn=<Subject CN name>,...; issuer: cn=<Issuer CN Name>,...) of the provided certificate is not contained in the accepted subjectAndIssuers list of the integration flow.

N.B., There are multiple potential causes for inbound HTTP 403 error.
This article aims only at the situation / error mentioned above.

• SAP Business Technology Platform
• SAP Integration Suite
• Cloud Integration

Client Certificate Authentication, 403, Certificate, User Role, Role Based, Cloud Integration, SAP Integration Suite, SAP Cloud Platform Integration, Cloud Platform Integration, SAP CPI, CPI, SCPI, HANA Cloud Integration, HCI, SAP HCI, tenant, iFlow, Integration Flow , KBA , LOD-HCI-PI-RT , Integration Runtime , Problem