b3270 tls-hello Indication

### TLS Hello Indication

TLS initialization message. Sent only within an initialize element.

Attribute | Always present? | Purpose
--- | --- | ---
supported | yes | true or false
provider | yes | Name of TLS provider library
options | no | List of supported options

Example:

    <tls-hello supported="true" provider="OpenSSL 1.0.1 14 Mar 2012" options="certFileType chainFile keyFile keyFileType keyPasswd acceptHostname verifyHostCert tls">

### TLS Options

The Toggle() action allows the TLS configuration to be changed. The tls-hello indication shows whether TLS is supported, and lists the TLS-related option keywords supported by this implementation (not all implementations support all options). Possible values include:

Option Name | Meaning
--- | ---
acceptHostname | Hostname to check against host certificate name
caDir | Directory holding CA root certificates
caFile | File holding CA root certificates
certFile | File holding client certificate to present
certFileType | Type of certFile (pem or asn1)
clientCert | Name of client certificate to present
chainFile | File holding chain of CA certificates
keyFile | File holding key for certFile
keyFileType | Type of keyFile (pem or asn1)
keyPasswd | Password for client certificate (file:xxx or string:xxx)
tls | true to accept the TELNET STARTTLS option (default), false to reject it
verifyHostCert | true to verify the host certificate (default), false to accept any certificate

b3270: Protocol - Operations - Indications