- if fingerprint.is_some() {
- // FIXME actually verify fingerprint via callback!
- ssl_connector_builder.set_verify(openssl::ssl::SslVerifyMode::NONE);
+ if let Some(expected) = fingerprint {
+ ssl_connector_builder.set_verify_callback(
+ openssl::ssl::SslVerifyMode::PEER,
+ move |_valid, ctx| {
+ let cert = match ctx.current_cert() {
+ Some(cert) => cert,
+ None => {
+ // should not happen
+ eprintln!("SSL context lacks current certificate.");
+ return false;
+ }
+ };
+
+ // skip CA certificates, we only care about the peer cert
+ let depth = ctx.error_depth();
+ if depth != 0 {
+ return true;
+ }
+
+ let fp = match cert.digest(openssl::hash::MessageDigest::sha256()) {
+ Ok(fp) => fp,
+ Err(err) => {
+ // should not happen
+ eprintln!("failed to calculate certificate FP - {}", err);
+ return false;
+ }
+ };
+ let fp_string = hex::encode(&fp);
+ let fp_string = fp_string
+ .as_bytes()
+ .chunks(2)
+ .map(|v| std::str::from_utf8(v).unwrap())
+ .collect::<Vec<&str>>()
+ .join(":");
+
+ let expected = expected.to_lowercase();
+ if expected == fp_string {
+ true
+ } else {
+ eprintln!("certificate fingerprint does not match expected fingerprint!");
+ eprintln!("expected: {}", expected);
+ eprintln!("encountered: {}", fp_string);
+ false
+ }
+ },
+ );