client certificate to upstream via nginx

[Vishwas Bm]

Hi

We have a client certificate in pem format and it is having below content
and all these certificates are present in a single file.
serverCertificate -> intermediate CA -> rootCA

Now in the nginx.conf have below directives set:

`
server {
 ...
 ssl_client_certificate ca-pg-ca.pem;
* ssl_verify_client optional_no_ca; *
 ssl_verify_depth 4;

 location ~* "^/" {
  ...
  proxy_set_header Host $best_http_host;

  # Pass the extracted client certificate to the backend
*  proxy_set_header ssl-client-cert $ssl_client_escaped_cert; *
  proxy_set_header ssl-client-verify $ssl_client_verify;
  proxy_set_header ssl-client-subject-dn $ssl_client_s_dn;
  proxy_set_header ssl-client-issuer-dn $ssl_client_i_dn;

  }

}`

Now in the nginx logs we see below traces:

`
{"message":"83#83: *874 http script var: '10.15.176.110:10443'"}
{"message":"83#83: *874 http script copy: 'ssl-client-cert'"}
{"message":"83#83: *874 http script var:
'-----BEGIN%20CERTIFICATE-----<ONLY_CLIENT_CERTIFICATE_IS_PRESENT_WITHOUT_INTERMEDIATE>-----END%20CERTIFICATE-----%0A'"}}

{"message":"83#83: *874 http script copy: 'ssl-client-verify'"}}
{"message":"83#83: *874 http script var: 'SUCCESS'"}}
{"message":"83#83: *874 http script copy: 'ssl-client-subject-dn'"}}
{"message":"83#83: *874 http script var:
'CN=clientcert.com,O=ABCD,L=Ba,ST=Ka,C=US'"}}

{"message":"83#83: *874 http script copy: 'ssl-client-issuer-dn'"}}
{"message":"83#83: *874 http script var:
'CN=intermediateca.com,O=Nk,ST=Ka,C=US'"}}

`

So based on above only the client certificate is sent to the upstream
server but our expectation was that the complete pem contents including all
the 3 certs (client, intermediate and root) will be sent to the backend.

Is our expectation correct or wrong ?
Any change has to be done to handle this ?

Nginx version used: 1.22.1



*Thanks & Regards,*

*Vishwas *
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