Files
proton-bridge/pkg/pmapi/dialer_pinning.go
2021-01-15 13:22:55 +00:00

94 lines
2.6 KiB
Go

// Copyright (c) 2021 Proton Technologies AG
//
// This file is part of ProtonMail 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"
"github.com/sirupsen/logrus"
)
// PinningTLSDialer wraps a TLSDialer to check fingerprints after connecting and
// to report errors if the fingerprint check fails.
type PinningTLSDialer struct {
dialer TLSDialer
// pinChecker is used to check TLS keys of connections.
pinChecker *pinChecker
// tlsIssueNotifier is used to notify something when there is a TLS issue.
tlsIssueNotifier func()
reporter *tlsReporter
// A logger for logging messages.
log logrus.FieldLogger
}
// NewPinningTLSDialer constructs a new dialer which only returns tcp connections to servers
// which present known certificates.
// If enabled, it reports any invalid certificates it finds.
func NewPinningTLSDialer(dialer TLSDialer) *PinningTLSDialer {
return &PinningTLSDialer{
dialer: dialer,
pinChecker: newPinChecker(TrustedAPIPins),
log: logrus.WithField("pkg", "pmapi/tls-pinning"),
}
}
func (p *PinningTLSDialer) SetTLSIssueNotifier(notifier func()) {
p.tlsIssueNotifier = notifier
}
func (p *PinningTLSDialer) EnableRemoteTLSIssueReporting(cm *ClientManager) {
p.reporter = newTLSReporter(p.pinChecker, cm)
}
// DialTLS dials the given network/address, returning an error if the certificates don't match the trusted pins.
func (p *PinningTLSDialer) DialTLS(network, address string) (net.Conn, error) {
conn, err := p.dialer.DialTLS(network, address)
if err != nil {
return nil, err
}
host, port, err := net.SplitHostPort(address)
if err != nil {
return nil, err
}
if err := p.pinChecker.checkCertificate(conn); err != nil {
if p.tlsIssueNotifier != nil {
go p.tlsIssueNotifier()
}
if tlsConn, ok := conn.(*tls.Conn); ok && p.reporter != nil {
p.reporter.reportCertIssue(
TLSReportURI,
host,
port,
tlsConn.ConnectionState(),
)
}
return nil, err
}
return conn, nil
}