all repos — flounder @ e6d27a6a56bc9bd140c233643855288ca1aa6f42

A small site builder for the Gemini protocol

gemini.go (view raw)

  1package main
  2
  3import (
  4	"bytes"
  5	"crypto/tls"
  6	"crypto/x509" // todo move into cert file
  7	"encoding/pem"
  8	"strings"
  9	// "fmt"
 10	"git.sr.ht/~adnano/gmi"
 11	"io/ioutil"
 12	"log"
 13	"os"
 14	"path"
 15	"text/template"
 16	"time"
 17)
 18
 19func gmiIndex(w *gmi.ResponseWriter, r *gmi.Request) {
 20	t, err := template.ParseFiles("templates/index.gmi")
 21	if err != nil {
 22		log.Fatal(err)
 23	}
 24	files, _ := getIndexFiles()
 25	users, _ := getUsers()
 26	data := struct {
 27		Domain string
 28		Files  []*File
 29		Users  []string
 30	}{
 31		Domain: "flounder.online",
 32		Files:  files,
 33		Users:  users,
 34	}
 35	t.Execute(w, data)
 36}
 37
 38func gmiPage(w *gmi.ResponseWriter, r *gmi.Request) {
 39	userName := strings.Split(r.URL.Host, ".")[0]
 40	fileName := path.Join(c.FilesDirectory, userName, r.URL.Path)
 41	data, err := ioutil.ReadFile(fileName)
 42	if err != nil {
 43		// TODO return 404 equivalent
 44		log.Fatal(err)
 45	}
 46	_, err = w.Write(data)
 47	if err != nil {
 48		// return internal server error
 49		log.Fatal(err)
 50	}
 51}
 52
 53func runGeminiServer() {
 54	log.Println("Starting gemini server")
 55	var server gmi.Server
 56
 57	if err := server.CertificateStore.Load("./tmpcerts"); err != nil {
 58		log.Fatal(err)
 59	}
 60	server.GetCertificate = func(hostname string, store *gmi.CertificateStore) *tls.Certificate {
 61		cert, err := store.Lookup(hostname)
 62		if err != nil {
 63			switch err {
 64			case gmi.ErrCertificateExpired:
 65				// Generate a new certificate if the current one is expired.
 66				log.Print("Old certificate expired, creating new one")
 67				fallthrough
 68			case gmi.ErrCertificateUnknown:
 69				// Generate a certificate if one does not exist.
 70				cert, err := gmi.NewCertificate(hostname, time.Minute)
 71				if err != nil {
 72					// Failed to generate new certificate, abort
 73					return nil
 74				}
 75				// Store and return the new certificate
 76				err = writeCertificate("./tmpcerts/"+hostname, cert)
 77				if err != nil {
 78					return nil
 79				}
 80				store.Add(hostname, cert)
 81				return &cert
 82			}
 83		}
 84		return cert
 85	}
 86
 87	// replace with wildcard cert
 88	server.HandleFunc(c.RootDomain, gmiIndex)
 89	server.HandleFunc("*."+c.RootDomain, gmiPage)
 90
 91	server.ListenAndServe()
 92}
 93
 94// writeCertificate writes the provided certificate and private key
 95// to path.crt and path.key respectively.
 96func writeCertificate(path string, cert tls.Certificate) error {
 97	crt, err := marshalX509Certificate(cert.Leaf.Raw)
 98	if err != nil {
 99		return err
100	}
101	key, err := marshalPrivateKey(cert.PrivateKey)
102	if err != nil {
103		return err
104	}
105
106	// Write the certificate
107	crtPath := path + ".crt"
108	crtOut, err := os.OpenFile(crtPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
109	if err != nil {
110		return err
111	}
112	if _, err := crtOut.Write(crt); err != nil {
113		return err
114	}
115
116	// Write the private key
117	keyPath := path + ".key"
118	keyOut, err := os.OpenFile(keyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
119	if err != nil {
120		return err
121	}
122	if _, err := keyOut.Write(key); err != nil {
123		return err
124	}
125	return nil
126}
127
128// marshalX509Certificate returns a PEM-encoded version of the given raw certificate.
129func marshalX509Certificate(cert []byte) ([]byte, error) {
130	var b bytes.Buffer
131	if err := pem.Encode(&b, &pem.Block{Type: "CERTIFICATE", Bytes: cert}); err != nil {
132		return nil, err
133	}
134	return b.Bytes(), nil
135}
136
137// marshalPrivateKey returns PEM encoded versions of the given certificate and private key.
138func marshalPrivateKey(priv interface{}) ([]byte, error) {
139	var b bytes.Buffer
140	privBytes, err := x509.MarshalPKCS8PrivateKey(priv)
141	if err != nil {
142		return nil, err
143	}
144	if err := pem.Encode(&b, &pem.Block{Type: "PRIVATE KEY", Bytes: privBytes}); err != nil {
145		return nil, err
146	}
147	return b.Bytes(), nil
148}