TLSContext (FB)

FUNCTION_BLOCK PUBLIC FINAL TLSContext IMPLEMENTS ITLSContext, ITLSContext_Internal

Encapsulates all the data neccecray to handle encrypted tcp connections

Static initialization, as shown in the following code snippet.

VAR
    commonName : STRING := 'MyRrasPi';
    ciCertInfo : NBS.CERT_INFO := (psInfo:=ADR(commonName), udiSize:=LEN(commonName));
    myTLSContext : NBS.TLSContext := (
        ePurpose:=NBS.PURPOSE.CLIENT_SIDE,
        sUseCaseName:='NBSTest',
        sTLSVersion:='1.3',
        ciCertInfo:=ciCertInfo,
        udiVerificationMode:=2
    );
END_VAR
InOut:

Scope

Name

Type

Initial

Comment

Input Const

sUseCaseName

STRING

A name to identify this context in the security manager

ePurpose

PURPOSE

This context can be used on the server side or on the client side.

sTLSVersion

TLS_VERSION

‘1.2’

A string to select the correct protocol version

sCipherList

CIPHER_LIST

STRUCT(psList := ADR(‘HIGH’), udiSize := 5)
A string to select the correct encryption cipher suites.
See for example: https://www.openssl.org/docs/man1.1.1/man1/ciphers.html#CIPHER-LIST-FORMAT

sHostname

HOSTNAME

A hostname to select the correct certificate on the server side.

udiVerificationMode

UDINT

1
1 => No peer verification
2 => Active Peer verification
(4) => 2+4 = 6 => Force termination, if no client certificate
(8) => 2+8=10 or 2+4+8 = 14 => Request client certificate only whithin initial handshake

ciCertInfo

REFERENCE TO CERT_INFO

A string to select the correct certificate in local certificate store

itfCertVerifer

ICertificateVerifier

A callback for application specific cerificate verification

Methods:

SetInitialValue

Structure: