Expand httputil

This expands the functionality in httputil.

It adds simple handlers for BasicAuth and redirecting to https

This adds several autocert related mechanisms to `httputil`

Author: directionless

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/stretchr/testify v1.2.1
 	go.opencensus.io v0.18.0
+	golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4
 	golang.org/x/sync v0.0.0-20181108010431-42b317875d0f // indirect
 	google.golang.org/appengine v1.3.0 // indirect
 	google.golang.org/grpc v1.14.0

go.sum

@@ -48,14 +48,22 @@ github.com/stretchr/testify v1.2.1 h1:52QO5WkIUcHGIR7EnGagH88x1bUzqGXTC5/1bDTUQ7
 github.com/stretchr/testify v1.2.1/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 go.opencensus.io v0.18.0 h1:Mk5rgZcggtbvtAun5aJzAtjKKN/t0R3jJPlWILlv938=
 go.opencensus.io v0.18.0/go.mod h1:vKdFvxhtzZ9onBp9VKHK8z/sRpBMnKAsufL7wlDrCOA=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4 h1:HuIa8hRrWRSrqYzx1qI49NNxhdi2PrY7gxVSq1JjLDc=
+golang.org/x/crypto v0.0.0-20190701094942-4def268fd1a4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd h1:nTDtHvHSdCn1m6ITfMRqtOd/9+7a3s8RBNOZ3eYZzJA=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f h1:Bl/8QSvNqXvPGPGXa2z5xUTmV7VDcZyvRZ+QQXkXTZQ=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e h1:o3PsSEY8E4eXWkXrIP9YJALUkVZqzHJT5DOasTyn8Vs=
 golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0 h1:g61tztE5qeGQ89tm6NTjjM9VPIm088od1l6aSorWRWg=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 google.golang.org/api v0.0.0-20180910000450-7ca32eb868bf/go.mod h1:4mhQ8q/RsB7i+udVvVy5NUi08OU8ZlA0gRVgrF7VFY0=

httputil/autocert.go

@@ -0,0 +1,57 @@
+package httputil
+
+import (
+	"net/http"
+	"time"
+
+	"github.com/pkg/errors"
+	"golang.org/x/crypto/acme"
+	"golang.org/x/crypto/acme/autocert"
+)
+
+type AcmOpt func(*autocert.Manager) error
+
+func WithLetsEncryptStaging() AcmOpt {
+	return func(m *autocert.Manager) error {
+		m.Client.DirectoryURL = "https://acme-staging.api.letsencrypt.org/directory"
+		return nil
+	}
+}
+
+func WithEmail(e string) AcmOpt {
+	return func(m *autocert.Manager) error {
+		m.Email = e
+		return nil
+	}
+}
+
+func WithRenewBefore(t time.Duration) AcmOpt {
+	return func(m *autocert.Manager) error {
+		m.RenewBefore = t
+		return nil
+	}
+}
+
+func WithHttpClient(c *http.Client) AcmOpt {
+	return func(m *autocert.Manager) error {
+		m.Client.HTTPClient = c
+		return nil
+	}
+}
+
+func NewAutocertManager(cache autocert.Cache, allowedHosts []string, opts ...AcmOpt) (*autocert.Manager, error) {
+	m := &autocert.Manager{
+		Prompt:     autocert.AcceptTOS,
+		HostPolicy: autocert.HostWhitelist(allowedHosts...),
+		Cache:      cache,
+		Client:     &acme.Client{},
+	}
+
+	for _, opt := range opts {
+		if err := opt(m); err != nil {
+			return nil, errors.Wrap(err, "applying option to autocert manager")
+		}
+	}
+
+	return m, nil
+}

httputil/handlers.go

@@ -0,0 +1,39 @@
+package httputil
+
+import (
+	"crypto/subtle"
+	"net/http"
+)
+
+// BasicAuthMiddleware is http middleware to authenticate based on a
+// predefined map of usernames and passwords.
+func BasicAuthMiddleware(basicauthPairs map[string][]byte, next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		username, password, ok := r.BasicAuth()
+		if !ok || username == "" {
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			return
+		}
+
+		// username and password must match
+		expectedPassword, ok := basicauthPairs[username]
+		if !ok || subtle.ConstantTimeCompare([]byte(password), expectedPassword) != 1 {
+			http.Error(w, "Unauthorized", http.StatusUnauthorized)
+			return
+		}
+
+		// handoff to the next handler
+		next.ServeHTTP(w, r)
+	})
+}
+
+// RedirectToSecureHandler is a simple handler to redirect to the secure URL.
+func RedirectToSecureHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Connection", "close")
+		url := r.URL
+		url.Scheme = "https"
+		url.Host = r.Host
+		http.Redirect(w, r, url.String(), http.StatusMovedPermanently)
+	})
+}

httputil/httputil.go

@@ -19,6 +19,18 @@ func WithTLSConfig(cfg *tls.Config) Option {
 	}
 }
 
+func WithReadTimeout(t time.Duration) Option {
+	return func(s *http.Server) {
+		s.ReadTimeout = t
+	}
+}
+
+func WithWriteTimeout(t time.Duration) Option {
+	return func(s *http.Server) {
+		s.WriteTimeout = t
+	}
+}
+
 // NewServer creates an HTTP Server with pre-configured timeouts and a secure TLS Config.
 func NewServer(addr string, h http.Handler, opts ...Option) *http.Server {
 	srv := http.Server{

tlsutil/tlsutil.go

@@ -61,6 +61,15 @@ func WithCertificates(certs []tls.Certificate) Option {
 	}
 }
 
+// WithGetCertificate sets the GetCertificate hook on
+// tls.Config.GetCertificate. It's the usual integration point for
+// autocert.
+func WithGetCertificate(getCertFunc func(*tls.ClientHelloInfo) (*tls.Certificate, error)) Option {
+	return func(config *tls.Config) {
+		config.GetCertificate = getCertFunc
+	}
+}
+
 // NewConfig returns a configured *tls.Config. By default, the TLS Config is set to
 // MinVersion of TLS 1.2 and a Modern Profile.
 //