After Oracle database server upgraded from 11.2.0.4 to 12.2.0.1, client application connections throw the following errors:
at org.apache.commons.dbcp.BasicDataSource.createPoolableConnectionFactory(BasicDataSource.java:1549)
at org.apache.commons.dbcp.BasicDataSource.createDataSource(BasicDataSource.java:1388)
at org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)
at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:83)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:446)
... 27 more
Caused by: java.sql.SQLException: ORA-28040: No matching authentication protocol
SOLUTION
Add the following line into sqlnet.ora file of ORACLE_HOME:
SQLNET.ALLOWED_LOGON_VERSION_SERVER=8
Then client application connects to new database working fine.