anonymous cypher suites for SSL (and a 12c pitfall)

If you configure your listener for encryption only, you do not really need authentication.

It works pretty fine until 11.2.0.2, I wrote multiple posts on ssl.

You add SSL_CLIENT_AUTHENTICATION=FALSE to your server sqlnet.ora and listener.ora and specify an “anon” cipher suite in your client. You do not need to validate the certificate, so a default wallet will do.


orapki wallet create -wallet . -auto_login_only

sqlnet.ora

WALLET_LOCATION=(SOURCE=(METHOD=FILE)(METHOD_DATA=(DIRECTORY=.)))
ssl_cipher_suites=(SSL_DH_anon_WITH_3DES_EDE_CBC_SHA)
NAMES.DIRECTORY_PATH=(TNSNAMES)

tnsnames.ora

DB01=(DESCRIPTION=(ADDRESS=(PROTOCOL=TCPS)(HOST=srv01.example.com)(PORT=1521))(CONNECT_DATA=(SID=DB01)))

or if you use java, the default truststore -usually located in $JAVA_HOME/jre/lib/security/cacerts, will also do.


    System.setProperty("oracle.net.ssl_cipher_suites", "SSL_DH_anon_WITH_DES_CBC_SHA");

On some plateform however you may get something like : IBM’s Client TrustManager does not allow anonymous cipher suites.

So far so good, but if you upgrade your listener to 11.2.0.3/4 or 12c, the anonymous suites won’t be accepted if not explicitely set up in sqlnet.ora. This is documented in Note 1434966.1

You will get something like “ORA-28860: Fatal SSL error”, “TNS-12560: TNS:protocol adapter error” in Oracle or “SSLHandshakeException: Received fatal alert: handshake_failure”, “SQLRecoverableException: I/O-Error: Received fatal alert: handshake_failure” in java.

There are two -obvious- ways to fix this. The preferred approach is to not use anonymous suite (they seem to have disappeared from the supported cypher suites in the doc).

For this task, you use another cipher suite. The easiest way is to not specify any or just use one like TLS_RSA_WITH_AES_128_CBC_SHA (java) / SSL_RSA_WITH_AES_128_CBC_SHA (sqlnet). Even if you do not use client authentication, you will then have to authenticate the server, and import the root ca in the wallet or the keystore.
sqlnet.ora


# comment out ssl_cipher_suites=(SSL_DH_anon_WITH_3DES_EDE_CBC_SHA)

java

// comment out : System.setProperty("oracle.net.ssl_cipher_suites", "SSL_DH_anon_WITH_DES_CBC_SHA");
System.setProperty("javax.net.ssl.trustStore","keystore.jks");
System.setProperty("javax.net.ssl.trustStoreType","JKS");
System.setProperty("javax.net.ssl.trustStorePassword","***");

Or, as documented in metalink, define the suite in sqlnet.ora and listener.ora if you use 11.2.0.3 or 11.2.0.4.

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