AIA (Authority Information Access) Transport Go

AIA-Transport-Go provides an http.Transport which uses the AIA (Authority Information Access) X.509 extension to resolve incomplete certificate chains during the tls handshake. See rfc3280 for more details.

Installation

go get github.com/fcjr/aia-transport-go

Usage

tr, err := aia.NewTransport()
if err != nil {
    log.Fatal(err)
}
client := http.Client{
    Transport: tr,
}
res, err := client.Get("https://incomplete-chain.badssl.com/")
if err != nil {
    log.Fatal(err)
}
fmt.Println(res.Status)

Todos

• Follow single incomplete AIA chain
• Tests
• CI & Code Coverage
• Documentation
• Chain Caching
• Certificate Caching
• Follow all possible issuing urls
• Benchmarks

Caveats

This library relies on x509.SystemCertPool() to gather the initial system root certificates to validate against. This function is not implemented on windows, however windows will resolve incomplete certificate chains via AIA automatically so this library simply returns a default http.Transport on windows which should be sufficient.¹

Footnotes

1. https://github.com/golang/go/issues/31773#issuecomment-582176197 ↩