GODT-35: Finish all details and make tests pass

pkg/pmapi/dialer_basic.go

@@ -0,0 +1,76 @@
+// Copyright (c) 2021 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package pmapi
+
+import (
+	"crypto/tls"
+	"net"
+	"net/http"
+	"time"
+)
+
+type TLSDialer interface {
+	DialTLS(network, address string) (conn net.Conn, err error)
+}
+
+// CreateTransportWithDialer creates an http.Transport that uses the given dialer to make TLS connections.
+func CreateTransportWithDialer(dialer TLSDialer) *http.Transport {
+	return &http.Transport{
+		DialTLS: dialer.DialTLS,
+
+		Proxy:                 http.ProxyFromEnvironment,
+		MaxIdleConns:          100,
+		IdleConnTimeout:       5 * time.Minute,
+		ExpectContinueTimeout: 500 * time.Millisecond,
+
+		// GODT-126: this was initially 10s but logs from users showed a significant number
+		// were hitting this timeout, possibly due to flaky wifi taking >10s to reconnect.
+		// Bumping to 30s for now to avoid this problem.
+		ResponseHeaderTimeout: 30 * time.Second,
+
+		// If we allow up to 30 seconds for response headers, it is reasonable to allow up
+		// to 30 seconds for the TLS handshake to take place.
+		TLSHandshakeTimeout: 30 * time.Second,
+	}
+}
+
+// BasicTLSDialer implements TLSDialer.
+type BasicTLSDialer struct {
+	cfg Config
+}
+
+// NewBasicTLSDialer returns a new BasicTLSDialer.
+func NewBasicTLSDialer(cfg Config) *BasicTLSDialer {
+	return &BasicTLSDialer{
+		cfg: cfg,
+	}
+}
+
+// DialTLS returns a connection to the given address using the given network.
+func (d *BasicTLSDialer) DialTLS(network, address string) (conn net.Conn, err error) {
+	dialer := &net.Dialer{Timeout: 30 * time.Second} // Alternative Routes spec says this should be a 30s timeout.
+
+	var tlsConfig *tls.Config
+
+	// If we are not dialing the standard API then we should skip cert verification checks.
+	if address != d.cfg.HostURL {
+		tlsConfig = &tls.Config{InsecureSkipVerify: true} // nolint[gosec]
+	}
+
+	return tls.DialWithDialer(dialer, network, address, tlsConfig)
+}