How to connect to postgresql using TLS certificate from java application?

Question

PostgreSQL

Hello, there is a java spring boot application that should connect via a private network using a tls certificate to a postgresql database on another server.
Certificates are all self-signed which are made by these commands:

how to generate certificates

openssl req -sha256 -new -x509 -days 5475 -nodes -out server-ca.crt -keyout server-ca.key
openssl req -sha256 -new -nodes -subj "/CN=10.0.0.3" -out server.csr -keyout server.key
openssl x509 -req -sha256 -days 5475 -in server.csr -CA server-ca.crt -CAkey server-ca.key -CAcreateserial -out server.crt

openssl req -sha256 -new -x509 -days 5475 -nodes -out client-ca.crt -keyout client-ca.key
openssl req -sha256 -new -nodes -subj "/CN=application" -out client.csr -keyout client.key
openssl x509 -req -sha256 -days 5475 -in client.csr -CA client-ca.crt -CAkey client-ca.key -CAcreateserial -out client.crt

Then from the root certificate of the client and the certificate signed by him, I created a new one:

how to collect the client certificate

cat client-ca.key client.crt > client.full.crt

And add certificates to trustStore:

how to add certificates to trustStore

keytool -keystore cacerts -alias client-full-crt -import -file client.full.crt
keytool -keystore cacerts -alias postgresql-server-crt -import -file server-ca.crt

I convert client.key to client.pk8 based on the documentation:

how to create a key in pk8 format

openssl pkcs8 -topk8 -inform PEM -in client.key -outform DER -out client.pk8 -v1 PBE-MD5-DES

In application.properties I write the config:

app config

spring.datasource.url=jdbc:postgresql://10.0.0.3:5432/application?ssl=true&sslfactory=org.postgresql.ssl.DefaultJavaSSLFactory&sslmode=verify-full&sslcert=/etc/ssl/postgres-client/client.crt&sslkey=/etc/ssl/postgres-client/client.pk8&sslrootcert=/etc/ssl/postgres-client/server-ca.crt

spring.datasource.username=application

And I run:

start app

java -Djavax.net.ssl.trustStore=cacerts -Djavax.net.ssl.trustStorePassword=changeit -jar backend.jar --spring.config.location=application.properties

And when starting the error:


And from the Postgres side:

2022-01-22 19:25:34.344 UTC [324199] [unknown]@[unknown] LOG:  could not accept SSL connection: sslv3 alert certificate unknown

Although when I try to connect via psql everything connects fine:

test via psql

psql "host=10.0.0.3 \
      user=application \
      dbname=application \
      sslmode=verify-full \
      sslrootcert=/etc/ssl/postgres-client/server-ca.crt \
      sslcert=/etc/ssl/postgres-client/client.crt \
      sslkey=/etc/ssl/postgres-client/client.key"

Also, when I connect without using a certificate, it also works fine.

And after a lot of hours of work and studying a couple of dozen articles, I could not solve this problem.
Tell me what's wrong, what's the problem?