is-tls-client-hello

Determine if a buffer contains a valid TLS ClientHello.

Why

You need to make a routing decision based on whether a connection wants to use TLS or not.

How

• returns 1 if the buffer contains a valid TLS ClientHello
• returns -1 if the buffer is not long enough to determine the record length
• returns -2 if TLS ContentType !== 22
• returns -3 if TLS ProtocolVersion is < 3.1 or > 3.3
• returns -4 if TLS HandshakeType !== 1
• returns the total number of bytes required to parse the record if the buffer is not long enough

Test

Verifies that requests from node's HTTP and HTTPS modules can be distiguished over a plain TCP socket.

$ npm test

Releases

• 2.0.0
  • It can be useful to know why a buffer does not contain a hello, in particular when the buffer is simply not long enough.

License

Public domain