Initial commit

README.md

@@ -0,0 +1,14 @@
+# MastoGem : a Mastodon proxy for Gemini
+
+## Build
+
+```
+$ go build
+```
+
+## Generate key and certificate
+
+```
+$ openssl genrsa -out key.rsa 4096
+$ openssl req -x509 -key key.rsa -out cert.pem -days 365 -subj "/CN=localhost"
+```

server.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"crypto/tls"
+	"log"
+	"net"
+	"net/http"
+	"fmt"
+	"mime"
+	"encoding/json"
+	"io/ioutil"
+	"strings"
+	"html"
+	"regexp"
+)
+
+type Blog struct {
+	Id      string `json:"id"`
+	Content string `json:"content"`
+	Date    string `json:"created_at"`
+}
+
+func main() {
+	err := mime.AddExtensionType(".gmi", "text/gemini")
+	if err != nil {
+		log.Fatalln("mime: %s", err)
+	}
+
+	listener := listen("0.0.0.0:1965", "cert.pem", "key.rsa")
+	log.Println("Server successfully started")
+	log.Println("Server is listening at 0.0.0.0:1956")
+
+	serve(listener)
+}
+
+func listen(address, certFile, keyFile string) net.Listener {
+	cert, err := tls.LoadX509KeyPair(certFile, keyFile)
+	if err != nil {
+		log.Fatalln("loadkeys: %s", err)
+	}
+	config := &tls.Config{
+		ClientAuth:   tls.RequestClientCert,
+		Certificates: []tls.Certificate{cert},
+		MinVersion:   tls.VersionTLS12,
+		InsecureSkipVerify: true,
+	}
+
+	listener, err := tls.Listen("tcp", address, config)
+	if err != nil {
+		log.Fatalln("failed to listen on 0.0.0.0:1965: %s", err)
+	}
+
+	return listener
+}
+
+func serve(listener net.Listener) {
+	for {
+		conn, err := listener.Accept()
+		if err != nil {
+			log.Println(err)
+		}
+
+		go handleConn(conn.(*tls.Conn))
+	}
+}
+
+func handleConn(conn *tls.Conn) {
+	defer conn.Close()
+
+	blogs := getBlog("https://mamot.fr", "138624")
+
+	_, err := fmt.Fprintf(conn, "20 text/gemini\r\n# Picasoft account toots\n")
+	if err != nil {
+		log.Println("handleConn: %s", err)
+		return
+	}
+
+	for _, blog := range blogs {
+		date := "```\n* Posted at " + blog.Date + "\n```\n"
+
+		text := blog.Content + "\n"
+		text = strings.ReplaceAll(text, "<p>", "")
+		text = strings.ReplaceAll(text, "</p>", "\n\n")
+		text = strings.ReplaceAll(text, "<br />", "\n")
+		text = strings.ReplaceAll(text, "</a>", "")
+		text = strings.ReplaceAll(text, "</span>", "")
+		regexString := "<a( [^>]*)?>"
+		regex, err := regexp.Compile(regexString)
+		if err != nil {
+			log.Println("regex: %s", err)
+			return
+		}
+		text = regex.ReplaceAllLiteralString(text, "")
+		regexString = "<span( [^>]*)?>"
+		regex, err = regexp.Compile(regexString)
+		if err != nil {
+			log.Println("regex: %s", err)
+			return
+		}
+		text = regex.ReplaceAllLiteralString(text, "")
+		text = html.UnescapeString(text)
+
+		_, err = fmt.Fprintf(conn, date + text)
+		if err != nil {
+			log.Println("read blogs: %s", err)
+			return
+		}
+	}
+}
+
+func getBlog(baseURL, account string) []Blog {
+	if baseURL == "" || account == "" {
+		log.Println("baseURL or account is empty")
+		return nil
+	}
+
+	resp, err := http.Get(baseURL + "/api/v1/accounts/" + account + "/statuses?exclude_reblogs=true")
+	if err != nil {
+		log.Println("Mastodon API request: %s", err)
+		return nil
+	}
+	if resp.StatusCode != 200 {
+		log.Println("Mastodon API response: %s", resp.Status)
+		return nil
+	}
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		log.Println("Mastodon response body: %s", err)
+	}
+
+	var blogs []Blog
+	json.Unmarshal(body, &blogs)
+
+	return blogs
+}