Where is the cargo certificate bundle

Anyone know where cargo on Windows (or curl specifically, cargo uses curl right?) looks for the ssl certificate bundle? I'm having trouble related to Respect git conventions when validating certs by alexcrichton · Pull Request #2408 · rust-lang/cargo · GitHub (behind a proxy that decrypts ssl connections.) However, I do have admin access to my machine, and did install the appropriate certificates. I still get this error though:

> cargo build --verbose
 Downloading xml-rs v0.3.0
unable to get packages from source

Caused by:
  failed to download package `xml-rs v0.3.0` from https://crates.io/api/v1/crates/xml-rs/0.3.0/download

Caused by:
  SSL connect error