One-way TLS ODB Client/Server With Self-signed Certificates In OS Truststore

In recent months, I've helped many customers understand there options for centralizing Oracle Database authentication.  One of those options requires Transport Layer Security (TLS) connection between the database client and database server in order to securely pass an access token to the database server.  When customers want to evaluate this solution, one of their challenges is how to setup TLS between the database and server for a proof of concept or internal validation.  There are three approaches that customers can take for setting up TLS between client and server:

1. Self-signed private certs with wallets - For demonstrations and proofs of concept

2. Self-signed private certs with host trust store - Next step toward production

3. Publicly signed certs - For production

The focus of this blog post is on the second of the three.

Here's the streamlined workflow that I use for setting up one-way TLS between Oracle Database client and server where the client wallet is distributed to Oracle Database clients. This comes from the Oracle Database security guide at https://docs.oracle.com/en/database/oracle/oracle-database/23/dbseg/configuring-transport-layer-security-encryption.html#GUID-03F216A2-76E0-47C9-9751-6F2D39BD75A1

As a side note, if you are not familiar with the WALLET_ROOT database parameter, please familiarize yourself with it at https://docs.oracle.com/en/database/oracle/oracle-database/23/refrn/WALLET_ROOT.html because it plays a large role in several security configuration options of the Oracle database including configuring TLS.

When specifying the SSL_CIPHER_SUITES in the database listener.ora and client tnsnames.ora, you will want to select the strongest cipher suites from the desired SSL_Version (1.3 or 1.2) that you want to support that all of the database clients support.  In this example, we will use version 1.2 and cipher suite TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384.

The full list of supported SSL_VERSION and SSL_CIPHER_SUITES values per database version are available here:

19c: https://docs.oracle.com/en/database/oracle/oracle-database/19/netrf/oracle-net-listener-parameters-in-listener-ora.html#GUID-1BCF9D1F-76D5-456A-B3DA-EC77C1C379E2

23ai: https://docs.oracle.com/en/database/oracle/oracle-database/23/netrf/oracle-net-listener-parameters-in-listener-ora.html#GUID-1BCF9D1F-76D5-456A-B3DA-EC77C1C379E2

Step 1: Setup Certificate Authority Server

In order to simplify this setup for a large number of databases, we first setup a private certificate authority (CA) on which we will create and sign individual database certificates.  This setup presumes that the Oracle Database software is installed on the host where orapki will be run.

1.1 Setup the environment variables on the dbca host.

export ORACLE_BASE="/u01/app/oracle/19c"
export ORACLE_HOME="$ORACLE_BASE/dbhome_1"
export WALLET_ROOT="$ORACLE_BASE/wallet_root"
PATH=$ORACLE_HOME/bin:$PATH

1.2 Create the root certificate authority wallet with a arbitrary distinguished name that makes it clear that it is the certificate authority.  For example, DN=root_ca.

mkdir -p $WALLET_ROOT/rootca_wallet/tls
orapki wallet create -wallet $WALLET_ROOT/rootca_wallet/tls -pwd Oracle123 -auto_login
orapki wallet add -wallet $WALLET_ROOT/rootca_wallet/tls -pwd Oracle123 -dn CN=root_ca -keysize 2048 -sign_alg sha256 -self_signed -validity 3500
orapki wallet export -wallet $WALLET_ROOT/rootca_wallet/tls -pwd Oracle123 -dn CN=root_ca -cert $WALLET_ROOT/rootca_wallet/root_wallet.crt

Step 2: Generate and sign DB and client certificates

2.1 Create database server wallet and sign database server (hrdb) certificate.  Note that the distinguished name of the database can be completely arbitrary.  In this example (CN=db_19c_hr), I encapsulated the role (db), version (19c) and application (hr). It could have just as easily been CN=db_hr.

mkdir -p $WALLET_ROOT/hrdb_wallet/tls
orapki wallet create  -wallet $WALLET_ROOT/hrdb_wallet/tls -pwd Oracle123 -auto_login
orapki wallet add -wallet $WALLET_ROOT/hrdb_wallet/tls -pwd Oracle123 -trusted_cert -cert $WALLET_ROOT/rootca_wallet/root_wallet.crt
orapki wallet add -wallet $WALLET_ROOT/hrdb_wallet/tls -pwd Oracle123 -keysize 2048 -dn CN=db_19c_hr
orapki wallet export -wallet $WALLET_ROOT/hrdb_wallet/tls -pwd Oracle123 -dn CN=db_19c_hr -request $WALLET_ROOT/hrdb_wallet/db_19c_hr.csr
orapki cert create -wallet $WALLET_ROOT/rootca_wallet/tls -pwd Oracle123 -request $WALLET_ROOT/hrdb_wallet/db_19c_hr.csr -cert $WALLET_ROOT/hrdb_wallet/db_19c_hr.crt -validity 3500 -sign_alg sha256
orapki wallet add -wallet $WALLET_ROOT/hrdb_wallet/tls -pwd Oracle123 -user_cert -cert $WALLET_ROOT/hrdb_wallet/db_19c_hr.crt

2.2 Create client wallet and load with certificate authority root certificate.  The purpose of the client wallet is to create a wallet that has the signing certificate authority's certificate (or certificate chain).

mkdir -p $WALLET_ROOT/client_wallet/tls
orapki wallet create -wallet $WALLET_ROOT/client_wallet/tls -pwd Oracle123 -auto_login
orapki wallet add -wallet $WALLET_ROOT/client_wallet/tls -pwd Oracle123 -trusted_cert -cert $WALLET_ROOT/rootca_wallet/root_wallet.crt

Step 3: Copy wallets to respective destinations

3.1 Copy hrdb_wallet to host of hrdb database server

export ORACLE_BASE="/u01/app/oracle/19c"
export WALLET_ROOT="$ORACLE_BASE/wallet_root"
rsync -Have ssh $WALLET_ROOT/hrdb_wallet/tls/. opc@hrdb:$WALLET_ROOT/tls

3.2  Lookup PDB GUIDs and copy hrdb wallet to each PDB GUID

ssh opc@hrdb
export ORACLE_BASE="/u01/app/oracle/19c"
export ORACLE_HOME="$ORACLE_BASE/dbhome_1"
export WALLET_ROOT="$ORACLE_BASE/wallet_root"
export TNS_ADMIN="$ORACLE_HOME/network/admin"
export ORACLE_SID="hrdb"
PATH=$ORACLE_HOME/bin:$PATH
$ORACLE_HOME/bin/sqlplus / as sysdba
SQL> select name,guid from v$containers;
SQL> quit;

for pdbguid in 262D482FB47D7B8BE0638400000A1737
do
  mkdir -p $WALLET_ROOT/$pdbguid/tls
  cp $WALLET_ROOT/tls/ewallet.p12 $WALLET_ROOT/$pdbguid/tls
  cp $WALLET_ROOT/tls/cwallet.sso $WALLET_ROOT/$pdbguid/tls
done

3.3 Copy client_wallet.crt certificate to host of each database thick client

rsync -Have ssh $WALLET_ROOT/rootca_wallet/root_wallet.crt opc@clientdb:/u01/app/oracle/root_wallet.crt 

Step 4: Configure 19c database server

4.1 Setup the database server environment variables on the hrdb host.

export ORACLE_BASE="/u01/app/oracle/19c"
export ORACLE_HOME="$ORACLE_BASE/dbhome_1"
export ORACLE_SID="hrdb"
export TNS_ADMIN="$ORACLE_HOME/network/admin"
PATH=$ORACLE_HOME/bin:$PATH

4.2 Configure sqlnet.ora

cat $ORACLE_HOME/network/admin/sqlnet.ora
SQLNET.AUTHENTICATION_SERVICES = (TCPS,NTS,BEQ)
SSL_CLIENT_AUTHENTICATION = FALSE
SSL_VERSION = 1.2
SSL_CIPHER_SUITES = (TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384)

4.3 Configure listener 

cat $ORACLE_HOME/network/admin/listener.ora
SSL_CLIENT_AUTHENTICATION = FALSE

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = hrdb.example.com)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
      (ADDRESS = (PROTOCOL = TCPS)(HOST = hrdb.example.com)(PORT = 2484))
      (SECURITY=(WALLET_LOCATION=/u01/app/oracle/19c/wallet_root/tls))
    )
  )

ADR_BASE_LISTENER = /u01/app/oracle/19c

4.4 Set the wallet_root parameter and restart the database and listener

sqlplus / as sysdba
SQL> alter system set wallet_root='/u01/app/oracle/19c/wallet_root' scope=spfile;
SQL> shutdown immediate;
SQL> quit;
lsnrctl stop
lsnrctl stop
sqlplus / as sysdba
SQL> startup;
SQL> alter pluggable database all open;
SQL> alter system register;
SQL> quit;

4.5 Configure host firewall of database server to allow inboud (a.k.a. ingress) connections to non-secure port (1521) and secure port (2848)

sudo firewall-cmd --permanent --zone=public --add-port=1521/tcp
sudo firewall-cmd --permanent --zone=public --add-port=2484/tcp
sudo firewall-cmd --reload
sudo firewall-cmd --list-all

Step 5: Configure 19c database client

Instructions for downloading 19c database client at https://www.braddiggs.com/2024/11/setup-production-oracle-19c-database.html

5.1 Setup the database client environment variables

export ORACLE_BASE="/u01/app/oracle/23ai"
export ORACLE_HOME="$ORACLE_BASE/client"
PATH=$ORACLE_HOME/bin:$PATH

5.2 Extract the 19c database client

mkdir -p $ORACLE_HOME
cd $ORACLE_HOME
unzip -qo /u01/bits/V982065-01.zip

5.3 Add database configurations to tnsnames.ora setting the WALLET_LOCATION to SYSTEM

cat $ORACLE_HOME/network/admin/tnsnames.ora
HRDB =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = hrdb.example.com)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = hrdb)
    )
  )

HRDB_SSL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCPS)(HOST = hrdb.example.com)(PORT = 2484))
    (SECURITY=(WALLET_LOCATION=SYSTEM))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = hrdb)
    )
  )

pdb1 =
  (DESCRIPTION=
    (ADDRESS=(PROTOCOL=TCP)(HOST=hrdb.example.com)(PORT=1521))
    (CONNECT_DATA=
      (SERVER = DEDICATED)
      (SERVICE_NAME=pdb1)
    )
  )

pdb1_ssl =
  (DESCRIPTION=
    (ADDRESS=(PROTOCOL=TCPS)(HOST=hrdb.example.com)(PORT=2484))
    (SECURITY=(WALLET_LOCATION=SYSTEM))
    (CONNECT_DATA=
      (SERVER=dedicated)
      (SERVICE_NAME=pdb1)
    )
  )

5.4 Configure sqlnet.ora

cat $ORACLE_HOME/network/admin/sqlnet.ora
WALLET_LOCATION=
  (SOURCE=  
    (METHOD=file)    
    (METHOD_DATA=    
      (DIRECTORY=/u01/app/oracle/tls)
    )
  )

SQLNET.AUTHENTICATION_SERVICES = (TCPS,NTS,BEQ)
SSL_CLIENT_AUTHENTICATION = FALSE
SSL_VERSION = 1.2
SSL_CIPHER_SUITES=(TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384)

5.5 Append the root_wallet.crt certificate to the host wallet

cat /u01/app/oracle/root_wallet.crt | sudo tee -a /etc/pki/tls/cert.pem
rm /u01/app/oracle/root_wallet.crt

Step 6: Test 19c client connections to the database

6.1 Setup the database client environment variables

export ORACLE_BASE="/u01/app/oracle/19c"
export ORACLE_HOME="$ORACLE_BASE/dbhome_1"
export LD_LIBRARY_PATH="$ORACLE_HOME/lib"
PATH=$ORACLE_HOME/bin:$PATH

6.2 Test to the container database (CDB) hrdb_ssl

sqlplus system/Oracle123@hrdb_ssl

6.3 Test to the pluggable database (PDB) pdb1_ssl

sqlplus system/Oracle123@pdb1_ssl

Step 7: Configure 23ai database client

Instructions for downloading 23ai database client at https://www.braddiggs.com/2024/11/setup-production-oracle-23ai-database.html

7.1 Setup the database client environment variables

export ORACLE_BASE="/u01/app/oracle/23ai"
export ORACLE_HOME="$ORACLE_BASE/client"
PATH=$ORACLE_HOME/bin:$PATH

7.2 Extract the 23ai database client

mkdir -p $ORACLE_HOME
cd $ORACLE_HOME
unzip -qo /u01/bits/V1044258-01.zip

7.3 Add database configurations to tnsnames.ora setting the WALLET_LOCATION to SYSTEM

cat $ORACLE_HOME/network/admin/tnsnames.ora
HRDB =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = hrdb.example.com)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = hrdb)
    )
  )

HRDB_SSL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCPS)(HOST = hrdb.example.com)(PORT = 2484))
    (SECURITY=(WALLET_LOCATION=SYSTEM))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = hrdb)
    )
  )

pdb1 =
  (DESCRIPTION=
    (ADDRESS=(PROTOCOL=TCP)(HOST=hrdb.example.com)(PORT=1521))
    (CONNECT_DATA=
      (SERVER = DEDICATED)
      (SERVICE_NAME=pdb1)
    )
  )

pdb1_ssl =
  (DESCRIPTION=
    (ADDRESS=(PROTOCOL=TCPS)(HOST=hrdb.example.com)(PORT=2484))
    (SECURITY=(WALLET_LOCATION=SYSTEM))
    (CONNECT_DATA=
      (SERVER=dedicated)
      (SERVICE_NAME=pdb1)
    )
  )

7.4 Configure sqlnet.ora

cat $ORACLE_HOME/network/admin/sqlnet.ora
SQLNET.AUTHENTICATION_SERVICES = (TCPS,NTS,BEQ)
SSL_CLIENT_AUTHENTICATION = FALSE
SSL_VERSION = 1.2
SSL_CIPHER_SUITES = (TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384)

7.5 Append the root_wallet.crt certificate to the host wallet

cat /u01/app/oracle/root_wallet.crt | sudo tee -a /etc/pki/tls/cert.pem
rm /u01/app/oracle/root_wallet.crt

Step 8: Test 23ai client connections to the database

Instructions for downloading 23ai database client at https://www.braddiggs.com/2024/11/setup-production-oracle-23ai-database.html

8.1 Setup the database client environment variables

export ORACLE_BASE="/u01/app/oracle/23ai"
export ORACLE_HOME="$ORACLE_BASE/dbhome_1"
export LD_LIBRARY_PATH="$ORACLE_HOME/lib"
PATH=$ORACLE_HOME/bin:$PATH

8.2 Test to the container database (CDB) hrdb_ssl

sqlplus system/Oracle123@hrdb_ssl

8.3 Test to the pluggable database (PDB) pdb1_ssl

sqlplus system/Oracle123@pdb1_ssl

For troubleshooting, see my blog post on Troubleshooting Oracle One-way TLS Connection Errors.