Upgrade to Bouncy Castle 1.68

2.1.2 Defects Fixed

    Some BigIntegers utility methods would fail for BigInteger.ZERO. This has been fixed.
    PGPUtil.isKeyRing() was not detecting secret sub-keys in its input. This has been fixed.
    The ASN.1 class, ArchiveTimeStamp was insisting on a value for the optional reducedHashTree field. This has been fixed.
    BCJSSE: Lock against multiple writers - a possible synchronization issue has been removed.

2.1.3 Additional Features and Functionality

    BCJSSE: Added support for system property com.sun.net.ssl.requireCloseNotify. Note that we are using a default value of 'true'.
    BCJSSE: 'TLSv1.3' is now a supported protocol for both client and server. For this release it is only enabled by default for the 'TLSv1.3' SSLContext, but can be explicitly enabled using 'setEnabledProtocols' on an SSLSocket or SSLEngine, or via SSLParameters.
    BCJSSE: Session resumption is now also supported for servers in TLS 1.2 and earlier. For this release it is disabled by default, and can be enabled by setting the boolean system property org.bouncycastle.jsse.server.enableSessionResumption to 'true'.
    The provider RSA-PSS signature names that follow the JCA naming convention.
    FIPS mode for the BCJSSE now enforces namedCurves for any presented certificates.
    PGPSignatureSubpacketGenerator now supports editing of a pre-existing sub-packet list.