Initial commit

.gitignore

@@ -0,0 +1 @@
+konbata

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 blank X
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

go.mod

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+module konbata
+
+go 1.16
+
+require git.sr.ht/~adnano/go-gemini v0.2.2 // indirect

go.sum

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+git.sr.ht/~adnano/go-gemini v0.2.2 h1:p2owKzrQ1wTgvPS5CZCPYArQyNUL8ZgYOHHrTjH9sdI=
+git.sr.ht/~adnano/go-gemini v0.2.2/go.mod h1:hQ75Y0i5jSFL+FQ7AzWVAYr5LQsaFC7v3ZviNyj46dY=
+golang.org/x/net v0.0.0-20210119194325-5f4716e94777 h1:003p0dJM77cxMSyCPFphvZf/Y5/NXf5fzg6ufd1/Oew=
+golang.org/x/net v0.0.0-20210119194325-5f4716e94777/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.3 h1:cokOdA+Jmi5PJGXLlLllQSgYigAEfHXJAERHVMaCc2k=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

main.go

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+package main
+
+import (
+	"os"
+	"fmt"
+	"log"
+	"sort"
+	"time"
+	"errors"
+	"context"
+	"strings"
+	"net/url"
+	"crypto/x509"
+	"encoding/xml"
+	"path/filepath"
+
+	"git.sr.ht/~adnano/go-gemini"
+	"git.sr.ht/~adnano/go-gemini/tofu"
+)
+
+var (
+	hosts     tofu.KnownHosts
+	hostsfile *tofu.HostWriter
+)
+
+func xdgDataHome() string {
+	if s, ok := os.LookupEnv("XDG_DATA_HOME"); ok {
+		return s
+	}
+	return filepath.Join(os.Getenv("HOME"), ".local", "share")
+}
+
+func init() {
+	path := filepath.Join(xdgDataHome(), "konbata", "known_hosts")
+	err := hosts.Load(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	hostsfile, err = tofu.OpenHostsFile(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+func trustCertificate(hostname string, cert *x509.Certificate) error {
+	host := tofu.NewHost(hostname, cert.Raw)
+	knownHost, ok := hosts.Lookup(hostname)
+	if ok {
+		// Check fingerprint
+		if knownHost.Fingerprint != host.Fingerprint {
+			return errors.New("fingerprint does not match!")
+		}
+		return nil
+	}
+
+	hosts.Add(host)
+	hostsfile.WriteHost(host)
+	return nil
+}
+
+func do(req *gemini.Request, via []*gemini.Request) (*gemini.Response, *gemini.Request, error) {
+	client := gemini.Client{
+		TrustCertificate: trustCertificate,
+	}
+	ctx := context.Background()
+	resp, err := client.Do(ctx, req)
+	if err != nil {
+		return resp, req, err
+	}
+
+	if resp.Status.Class() == gemini.StatusRedirect {
+		via = append(via, req)
+		if len(via) > 5 {
+			return resp, req, errors.New("too many redirects")
+		}
+
+		target, err := url.Parse(resp.Meta)
+		if err != nil {
+			return resp, req, err
+		}
+		if target.Scheme != "gemini" && target.Scheme != "" {
+			return resp, req, errors.New(fmt.Sprintf("tried to redirect to scheme %s", target.Scheme))
+		}
+		target = req.URL.ResolveReference(target)
+		redirect := *req
+		redirect.URL = target
+		return do(&redirect, via)
+	}
+
+	return resp, req, err
+}
+
+func main() {
+	if len(os.Args) == 0 {
+		fmt.Fprintf(os.Stderr, "Usage: konbata <url>\n")
+		os.Exit(1)
+	}
+	if len(os.Args) != 2 {
+		fmt.Fprintf(os.Stderr, "Usage: %s <url>\n", os.Args[0])
+		os.Exit(1)
+	}
+
+	req, err := gemini.NewRequest(os.Args[1])
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	resp, req, err := do(req, nil)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer resp.Body.Close()
+
+	if resp.Status.Class() != gemini.StatusSuccess {
+		log.Fatalf("%d %s", resp.Status, resp.Meta)
+	}
+	aw := AtomWriter{
+		Title: "",
+		Items: nil,
+	}
+	gemini.ParseLines(resp.Body, aw.Handle)
+	sort.Sort(ByTime(aw.Items))
+	feed := &Feed{
+		XMLNS: "http://www.w3.org/2005/Atom",
+		Link: &FeedLink{
+			Href: req.URL.String(),
+		},
+		Id: req.URL.String(),
+		Entries: nil,
+	}
+	if aw.Title == "" {
+		feed.Title = req.URL.String()
+	} else {
+		feed.Title = aw.Title
+	}
+	if len(aw.Items) == 0 {
+		feed.Updated = time.Now().Format(time.RFC3339)
+	} else {
+		feed.Updated = aw.Items[0].Date.Format(time.RFC3339)
+	}
+	for i := len(aw.Items); i != 0; i-- {
+		item := aw.Items[i - 1]
+		link, err := req.URL.Parse(item.Link)
+		if err != nil {
+			log.Fatal(err)
+		}
+		feed.Entries = append(feed.Entries, &FeedEntry{
+			Title: item.Title,
+			Link: &EntryLink{
+				Href: link.String(),
+				Rel: "alternate",
+			},
+			Id: link.String(),
+			Updated: item.Date.Format(time.RFC3339),
+		})
+	}
+	out, _ := xml.MarshalIndent(feed, "", "    ")
+	fmt.Println(string(out))
+}
+
+type Feed struct {
+	XMLName xml.Name `xml:"feed"`
+	XMLNS   string `xml:"xmlns,attr"`
+	Title   string `xml:"title"`
+	Link    *FeedLink `xml:"link"`
+	Updated string `xml:"updated"`
+	Id      string `xml:"id"`
+	Entries []*FeedEntry `xml:"entry"`
+}
+type FeedLink struct {
+	XMLName xml.Name `xml:"link"`
+	Href    string `xml:"href,attr"`
+}
+type FeedEntry struct {
+	XMLName xml.Name `xml:"entry"`
+	Title   string `xml:"title"`
+	Link    *EntryLink `xml:"link"`
+	Id      string `xml:"id"`
+	Updated string `xml:"updated"`
+}
+type EntryLink struct {
+	XMLName xml.Name `xml:"link"`
+	Href    string `xml:"href,attr"`
+	Rel    string `xml:"rel,attr"`
+}
+
+type FeedItem struct {
+	Date  time.Time
+	Title string
+	Link  string
+}
+
+type ByTime []FeedItem
+func (a ByTime) Len() int {
+	return len(a)
+}
+func (a ByTime) Less(i, j int) bool {
+	return a[i].Date.Before(a[j].Date)
+}
+func (a ByTime) Swap(i, j int) {
+	a[i], a[j] = a[j], a[i]
+}
+
+type AtomWriter struct {
+	Title string
+	Items []FeedItem
+}
+
+func (a *AtomWriter) Handle(line gemini.Line) {
+	switch line := line.(type) {
+	case gemini.LineLink:
+		runes := []rune(line.Name)
+		t, err := time.Parse("2006-01-02", string(runes[:10]))
+		if err == nil {
+			a.Items = append(a.Items, FeedItem{
+				Date: t,
+				Title: strings.TrimSpace(strings.TrimLeft(strings.TrimSpace(string(runes[10:])), ":-")),
+				Link: string(line.URL),
+			})
+		}
+	case gemini.LineHeading1:
+		if a.Title == "" {
+			a.Title = string(line)
+		}
+	}
+}