package backend import ( "crypto/tls" "crypto/x509" "encoding/pem" "io/ioutil" "net" "net/http" "strings" "time" "github.com/restic/restic/internal/debug" "github.com/restic/restic/internal/errors" ) // TransportOptions collects various options which can be set for an HTTP based // transport. type TransportOptions struct { // contains filenames of PEM encoded root certificates to trust RootCertFilenames []string // contains the name of a file containing the TLS client certificate and private key in PEM format TLSClientCertKeyFilename string } // readPEMCertKey reads a file and returns the PEM encoded certificate and key // blocks. func readPEMCertKey(filename string) (certs []byte, key []byte, err error) { data, err := ioutil.ReadFile(filename) if err != nil { return nil, nil, errors.Wrap(err, "ReadFile") } var block *pem.Block for { if len(data) == 0 { break } block, data = pem.Decode(data) if block == nil { break } switch { case strings.HasSuffix(block.Type, "CERTIFICATE"): certs = append(certs, pem.EncodeToMemory(block)...) case strings.HasSuffix(block.Type, "PRIVATE KEY"): if key != nil { return nil, nil, errors.Errorf("error loading TLS cert and key from %v: more than one private key found", filename) } key = pem.EncodeToMemory(block) default: return nil, nil, errors.Errorf("error loading TLS cert and key from %v: unknown block type %v found", filename, block.Type) } } return certs, key, nil } // Transport returns a new http.RoundTripper with default settings applied. If // a custom rootCertFilename is non-empty, it must point to a valid PEM file, // otherwise the function will return an error. func Transport(opts TransportOptions) (http.RoundTripper, error) { // copied from net/http tr := &http.Transport{ Proxy: http.ProxyFromEnvironment, DialContext: (&net.Dialer{ Timeout: 30 * time.Second, KeepAlive: 30 * time.Second, DualStack: true, }).DialContext, ForceAttemptHTTP2: true, MaxIdleConns: 100, MaxIdleConnsPerHost: 100, IdleConnTimeout: 90 * time.Second, TLSHandshakeTimeout: 10 * time.Second, ExpectContinueTimeout: 1 * time.Second, TLSClientConfig: &tls.Config{}, } if opts.TLSClientCertKeyFilename != "" { certs, key, err := readPEMCertKey(opts.TLSClientCertKeyFilename) if err != nil { return nil, err } crt, err := tls.X509KeyPair(certs, key) if err != nil { return nil, errors.Errorf("parse TLS client cert or key: %v", err) } tr.TLSClientConfig.Certificates = []tls.Certificate{crt} } if opts.RootCertFilenames != nil { pool := x509.NewCertPool() for _, filename := range opts.RootCertFilenames { if filename == "" { return nil, errors.Errorf("empty filename for root certificate supplied") } b, err := ioutil.ReadFile(filename) if err != nil { return nil, errors.Errorf("unable to read root certificate: %v", err) } if ok := pool.AppendCertsFromPEM(b); !ok { return nil, errors.Errorf("cannot parse root certificate from %q", filename) } } tr.TLSClientConfig.RootCAs = pool } // wrap in the debug round tripper (if active) return debug.RoundTripper(tr), nil }