From 146785207baa7f9029e91439ec41e176ccd0ef78 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Wed, 29 Sep 2021 22:46:58 +0300
Subject: [PATCH] Initial commit

---
 cmd/meta4-create/main.go | 141 +++++++++++++++++++++++++++++++++++++++
 go.mod                   |   3 +
 2 files changed, 144 insertions(+)
 create mode 100644 cmd/meta4-create/main.go
 create mode 100644 go.mod

diff --git a/cmd/meta4-create/main.go b/cmd/meta4-create/main.go
new file mode 100644
index 0000000..2289e8a
--- /dev/null
+++ b/cmd/meta4-create/main.go
@@ -0,0 +1,141 @@
+/*
+meta4a -- Metalink 4.0 utility
+Copyright (C) 2021 Sergey Matveev <stargrave@stargrave.org>
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, version 3 of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+// Metalink 4.0 utility
+package main
+
+import (
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/hex"
+	"encoding/xml"
+	"flag"
+	"io"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"time"
+)
+
+const (
+	Generator       = "meta4ra/0.1.0"
+	GPGSigMediaType = "application/pgp-signature"
+)
+
+type Metalink struct {
+	XMLName   xml.Name  `xml:"urn:ietf:params:xml:ns:metalink metalink"`
+	Files     []File    `xml:"file"`
+	Generator string    `xml:"generator,,omitempty"`
+	Published time.Time `xml:"published,,omitempty"`
+}
+
+type File struct {
+	XMLName     xml.Name   `xml:"file"`
+	Name        string     `xml:"name,attr"`
+	Description string     `xml:"description,,omitempty"`
+	Hashes      []Hash     `xml:"hash,,omitempty"`
+	MetaURLs    []MetaURL  `xml:"metaurl,,omitempty"`
+	Signature   *Signature `xml:"signature"`
+	Size        uint64     `xml:"size,,omitempty"`
+	URLs        []URL      `xml:"url,,omitempty"`
+}
+
+type URL struct {
+	XMLName xml.Name `xml:"url"`
+	URL     string   `xml:",chardata"`
+}
+
+type Signature struct {
+	XMLName   xml.Name `xml:"signature"`
+	MediaType string   `xml:"mediatype,attr"`
+	Signature string   `xml:",cdata"`
+}
+
+type Hash struct {
+	XMLName xml.Name `xml:"hash"`
+	Type    string   `xml:"type,attr"`
+	Hash    string   `xml:",chardata"`
+}
+
+type MetaURL struct {
+	XMLName   xml.Name `xml:"metaurl"`
+	MediaType string   `xml:"mediatype,attr"`
+	URL       string   `xml:",chardata"`
+}
+
+func main() {
+	file := flag.String("file", "", "Path to file")
+	desc := flag.String("desc", "", "Description")
+	sig := flag.String("sig", "", "Path to signature file")
+	torrent := flag.String("torrent", "", "Torrent URL")
+	log.SetFlags(log.Lshortfile)
+	flag.Parse()
+	urls := make([]URL, 0, len(flag.Args()))
+	for _, u := range flag.Args() {
+		urls = append(urls, URL{URL: u})
+	}
+	fd, err := os.Open(*file)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	fi, err := fd.Stat()
+	if err != nil {
+		log.Fatalln(err)
+	}
+	sha256Hasher := sha256.New()
+	sha512Hasher := sha512.New()
+	_, err = io.Copy(io.MultiWriter(sha256Hasher, sha512Hasher), fd)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	f := File{
+		Name:        filepath.Base(*file),
+		Description: *desc,
+		Size:        uint64(fi.Size()),
+		URLs:        urls,
+		Hashes: []Hash{
+			{Type: "sha-256", Hash: hex.EncodeToString(sha256Hasher.Sum(nil))},
+			{Type: "sha-512", Hash: hex.EncodeToString(sha512Hasher.Sum(nil))},
+		},
+	}
+	if *sig != "" {
+		sigData, err := ioutil.ReadFile(*sig)
+		if err != nil {
+			log.Fatalln(err)
+		}
+		f.Signature = &Signature{
+			MediaType: GPGSigMediaType,
+			Signature: "\n" + string(sigData),
+		}
+	}
+	if *torrent != "" {
+		f.MetaURLs = []MetaURL{{MediaType: "torrent", URL: *torrent}}
+	}
+	m := Metalink{
+		Files:     []File{f},
+		Generator: Generator,
+		Published: time.Now().UTC().Truncate(time.Second),
+	}
+	out, err := xml.MarshalIndent(&m, "", "  ")
+	if err != nil {
+		log.Fatalln(err)
+	}
+	os.Stdout.Write([]byte(xml.Header))
+	os.Stdout.Write(out)
+	os.Stdout.Write([]byte("\n"))
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..1191e6f
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module go.stargrave.org/meta4ra
+
+go 1.17
-- 
2.44.0