tls: docs error regarding `dhparam`

[silverwind]

The docs say:

dhparam: DH parameter file to use for DHE key agreement. Use openssl dhparam command to create it. If the file is invalid to load, it is silently discarded.

The fact that this seems to take a file instead of a buffer or string strikes me odd, as all other TLS options take these types. I've searched a bit and it seems there are no fs calls to read such a file. I see this in lib/_tls_common.js:

 if (options.dhparam) c.context.setDHParam(options.dhparam);

Could it be that the docs are just plainly wrong about this option?

[silverwind]

cc: @shigeki @indutny
original pr: nodejs/node-v0.x-archive#8272

[silverwind]

Reading through test/simple/test-tls-dhe.js makes it pretty obvious that the fs call happens in module-space. Can anyone confirm that crypto handles both string and buffer? I'll submit a PR.

[indutny]

Yeah, I'm +1 for buffer, though we may need to try to load file anyway, since we are doing it now. Mind helping with this?

[silverwind]

If buffer isn't supported yet, I can add it. Should be easy enough as cert, ca and key support it already, so I can lend code from these parts.

[shigeki]

@silverwind Good catch. Yes, it is not a file but string or Buffer that are the same as other pem parameters. Could you submit a PR to fix this? Thanks.

[silverwind]

Sure, will do a PR tomorrow if that's timely enough. You mean that string and buffer are already supported?

[shigeki]

Yes, both is supported. I've just tested it with using fs.readFileSync(path + '/dh' + n + '.pem').toString() .