use rfc2047decode in fixMangledMediaType for #134

[requaos]

No description provided.

[coveralls]

Coverage increased (+0.4%) to 88.189% when pulling d9268eb on requaos:requaos/consolidaterfc2047decoder into d24345a on jhillyerd:develop.

[requaos]

@jhillyerd Nevermind, I was able to reproduce with GOROOT v1.13.1

[requaos]

golang/go#34540
net/http (through net/textproto) used to accept and normalize invalid HTTP/1.1 headers with a space before the colon, in violation of RFC 7230. If a Go server is used behind a reverse proxy that accepts and forwards but doesn't normalize such invalid headers, the reverse proxy and the server can interpret the headers differently. This can lead to filter bypasses or request smuggling, the latter if requests from separate clients are multiplexed onto the same connection by the proxy. Such invalid headers are now rejected by Go servers, and passed without normalization to Go client applications.

This issue is CVE-2019-16276 and is fixed in Go 1.13.1 and Go 1.12.10.

[requaos]

@jhillyerd Considering that the above CVE applies to HTTP/1.1 headers, and is specifically for scenarios like:
HeaderKey : HeaderValue/r/n
I propose adding to the input filter to correct cases specific to this.

[jhillyerd]

This all looks good to me.

[dcormier]

Might want to check if \t is handled or not. I thought when I glanced at the golang change that that case is also different now.