Host name check in Custom Trust Manager - ssl-certificate

Question

We have a java client that allows both secure and non-secure connections to LDAP hosts.
It comes as part of a software suite which
has its own server component.
We are good with non-secure connections but need to switch to secure only.
The trusted public certificates are maintained (root+intermediate+host are copy pasted into one PEM file) in a
central location with the server component external to the clients.
The custom trust manager downloads the externally held trusted certificates on demand
and builds the trusted certificate chain. This way, I guess, it avoids pre-saving the trusted certicate chain in each client.
Our LDAP hosts are load balanced and that setup has not gone well with the trust manager. When we investigated, we found two questionable lines
in the code.
An environment variable to by-pass the host name verification.
if ("T".equals(System.getenv("IGNORE_HOSTNAME_CHECK"))) return true;
It seems like doing something similar to below which I have seen elsewhere.
HostnameVerifier allHostsValid = new HostnameVerifier() {
public boolean verify(String hostname, SSLSession session) {
return true;
}
};
HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
Host name check relies on CN value of subject alone.
if (this.tgtHostname.equalsIgnoreCase(leafCn)) return true;
I have skimmed through some RFCs related to TLS and have come across SNI, SAN:DNSName and MITM warnings
but my rudimentary knowledge is not enough to make a case one way or the other.
Any advice on improvements (or against the use of it altogether) around commented out lines labelled H1 and H2 will be greatly valued.
I intend to pass them on to the right entity later.
The cut-down version of checkServerTrusted() of the custom trust manager is pasted below.
public void checkServerTrusted(X509Certificate[] certsRcvdFromTgt, String authType) throws CertificateException
{
// Some stuff
// Verify that the last certificate in the chain corresponds to the tgt server we want to access.
checkLastCertificate(certsRcvdFromTgt[certsRcvdFromTgt.length - 1]);
// Some more stuff
}
private boolean checkLastCertificate(X509Certificate leafCert) throws CertificateException
{
// need some advice here ... (H1)
if ("T".equals(System.getenv("IGNORE_HOSTNAME_CHECK"))) return true;
try
{
String leafCn = null;
X500Principal subject = leafCert.getSubjectX500Principal();
String dn = subject.getName();
LdapName ldapDN = new LdapName(dn);
for (Rdn rdn : ldapDN.getRdns())
{
if (rdn.getType().equalsIgnoreCase("cn"))
{
leafCn = rdn.getValue().toString();
break;
}
}
// need some advice here ... (H2)
if (this.tgtHostname.equalsIgnoreCase(leafCn)) return true;
}
catch (InvalidNameException e){/*error handling*/}
throw new CertificateException("Failed to verify that the last certificate in the chain is for target " + this.tgtHostname);
}