add assembly module that generates new client locally

domain/generator/assemble.go

@@ -0,0 +1,188 @@
+package generator
+
+import (
+	cryptorand "crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"github.com/reddec/tinc-boot/scripts"
+	"io/ioutil"
+	"math/rand"
+	"net"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	defMask     = 16
+	defNetwork  = "dnet"
+	defPlatform = "amd64"
+	defPrefix   = "172.173"
+	defKeyBits  = 4096
+)
+
+const (
+	minimalPort   = 1024
+	filterPattern = `[^a-z0-9]+`
+)
+
+type Config struct {
+	Platform string   `form:"platform"`
+	Network  string   `form:"network"`
+	Name     string   `form:"name"`
+	Config   string   `form:"config"`
+	Prefix   string   `form:"prefix"`
+	Mask     int      `form:"mask"`
+	Port     int      `form:"port"`
+	KeyBits  int      `form:"keybits"`
+	Public   []string `form:"public"`
+}
+
+type Assembly struct {
+	Script    []byte
+	Config    Config
+	PublicKey string
+}
+
+func (cfg *Config) Generate(currentNetDir string) (*Assembly, error) {
+	if cfg.Name == "" {
+		return nil, errors.New("name not defined")
+	}
+	if cfg.Mask == 0 {
+		cfg.Mask = defMask
+	}
+	if cfg.Network == "" {
+		cfg.Network = defNetwork
+	}
+	if cfg.Platform == "" {
+		cfg.Platform = defPlatform
+	}
+	if cfg.Prefix == "" {
+		cfg.Prefix = defPrefix
+	}
+	if cfg.KeyBits == 0 {
+		cfg.KeyBits = defKeyBits
+	}
+	disabledSymbols := regexp.MustCompile(filterPattern)
+
+	cfg.Network = disabledSymbols.ReplaceAllString(strings.ToLower(cfg.Network), "")
+	cfg.Name = disabledSymbols.ReplaceAllString(strings.ToLower(cfg.Name), "")
+	if cfg.Name == "" {
+		return nil, errors.New("name contains only disabled symbols")
+	}
+	ip, err := cfg.generateIP()
+	if err != nil {
+		return nil, err
+	}
+	if cfg.Port == 0 {
+		cfg.Port = minimalPort + rand.Intn(65535-minimalPort)
+	}
+	publicNodes, err := findAllPublicNodes(filepath.Join(currentNetDir, "hosts"))
+	if err != nil {
+		return nil, err
+	}
+	keys, err := GenerateKeys(cfg.KeyBits)
+	if err != nil {
+		return nil, err
+	}
+	script := &scripts.AssemblyParam{
+		Public:      cfg.Public,
+		Name:        cfg.Name,
+		Network:     cfg.Network,
+		Address:     ip.String(),
+		Mask:        cfg.Mask,
+		Port:        cfg.Port,
+		Platform:    cfg.Platform,
+		ConnectTo:   publicNodes,
+		HostPublic:  keys.Public,
+		HostPrivate: keys.Private,
+	}
+
+	scriptData, err := script.Render()
+	if err != nil {
+		return nil, err
+	}
+	return &Assembly{
+		Script:    scriptData,
+		Config:    *cfg,
+		PublicKey: keys.Public,
+	}, nil
+}
+
+func (cfg *Config) generateIP() (net.IP, error) {
+	parts := strings.Split(cfg.Prefix, ".")
+	if len(parts) > 4 {
+		return nil, errors.New("invalid prefix - too long")
+	}
+	if len(parts) == 1 && parts[0] == "" {
+		parts = nil
+	}
+	var ip [net.IPv4len]byte
+	for i, part := range parts {
+		segment, err := strconv.ParseUint(part, 10, 8)
+		if err != nil {
+			return nil, fmt.Errorf("invalid prefix: %v", err)
+		}
+		ip[i] = byte(segment)
+	}
+	rand.Seed(time.Now().UnixNano())
+	for i := len(parts); i < 4; i++ {
+		var segment int
+		if i < 3 {
+			segment = rand.Intn(254)
+		} else {
+			segment = 1 + rand.Intn(253)
+		}
+		ip[i] = byte(segment)
+	}
+	return net.IP(ip[:]), nil
+}
+
+func findAllPublicNodes(rootDir string) (map[string]string, error) {
+	list, err := ioutil.ReadDir(rootDir)
+	if err != nil {
+		return nil, err
+	}
+	public := map[string]string{}
+	for _, item := range list {
+		if item.IsDir() {
+			continue
+		}
+		content, err := ioutil.ReadFile(filepath.Join(rootDir, item.Name()))
+		if err != nil {
+			return nil, err
+		}
+		if strings.Contains(string(content), "Address") {
+			public[item.Name()] = string(content)
+		}
+	}
+	return public, nil
+}
+
+type Keys struct {
+	Private string
+	Public  string
+}
+
+func GenerateKeys(bitSize int) (*Keys, error) {
+	priv, err := rsa.GenerateKey(cryptorand.Reader, bitSize)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Keys{
+		Private: string(pem.EncodeToMemory(&pem.Block{
+			Type:  "RSA PRIVATE KEY",
+			Bytes: x509.MarshalPKCS1PrivateKey(priv),
+		})),
+		Public: string(pem.EncodeToMemory(&pem.Block{
+			Type:  "RSA PUBLIC KEY",
+			Bytes: x509.MarshalPKCS1PublicKey(&priv.PublicKey),
+		})),
+	}, nil
+}

domain/generator/assemble_test.go

@@ -0,0 +1,15 @@
+package generator
+
+import "testing"
+
+func TestConfig_Generate(t *testing.T) {
+	cfg := Config{
+		Name: "xyz",
+	}
+	script, err := cfg.Generate("/etc/tinc/dnet")
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	t.Log(string(script.Script))
+}

scripts/assembly.go

@@ -0,0 +1,81 @@
+package scripts
+
+import (
+	"bytes"
+	"text/template"
+)
+
+var Assembly = template.Must(template.New("").Parse(`#!/usr/bin/env bash
+set -e -o pipefail -x
+
+BIN_URL="${BIN_URL:-https://github.com/reddec/tinc-boot/releases/latest/download/tinc-boot_linux_{{.Platform}}.tar.gz}"
+BIN_DIR="${BIN_DIR:-/usr/local/bin}"
+BIN="$BIN_DIR/tinc-boot"
+NETWORK="${NETWORK:-{{.Network}}}"
+PORT="${PORT:-{{.Port}}}"
+MASK="${MASK:-{{.Mask}}}"
+ADDRESS="${ADDRESS:-{{.Address}}}"
+NAME="${NAME:-{{.Name}}}"
+ROOT="/etc/tinc/$NETWORK"
+
+if ! (( ${EUID:-0} || $(id -u) )); then
+	echo "the script should be run under root/sudo"
+	exit 1
+fi
+
+if ! command -v "$BIN"; then
+    echo "Installing tinc-boot to $BIN_DIR"
+    curl -L "$BIN_URL" | tar -xz -C "$BIN_DIR" tinc-boot
+    chmod +x "$BIN"
+fi
+
+"$BIN" gen\
+  --name "$NAME" \
+  --network "$NETWORK" --bin "$BIN" \
+  --no-gen-key\ # we will use key bellow
+  --no-bin-copy\ # already downloaded above
+  --bin "$BIN"\ # path to binary that we just obtained
+  --port "$PORT"\
+  --mask "$MASK"\
+  --standalone \
+  {{range $name, $file := .ConnectTo}}--connect-to "{{$name}}" {{end}}{{with .ConnectTo}}\{{end}}
+  --prefix "$ADDRESS"{{with .Public}}\{{end}}
+  {{range .Public}}--public "{{.}}" {{end}}
+
+cat - >> "$ROOT/hosts/${NAME}" <<EOF
+{{.HostPublic}}
+EOF
+
+cat - > "$ROOT/rsa_key.priv" <<EOF
+{{.HostPrivate}}
+EOF
+
+chmod u=rw "$ROOT/rsa_key.priv"
+{{range $name, $file := .ConnectTo}}
+cat - >> "$ROOT/hosts/{{$name}}" <<EOF
+{{$file}}
+EOF
+{{end}}
+
+systemctl enable tinc@${NETWORK}
+systemctl start tinc@${NETWORK}
+`))
+
+type AssemblyParam struct {
+	Public      []string
+	Platform    string
+	Name        string
+	Network     string
+	Address     string
+	Mask        int
+	Port        int
+	ConnectTo   map[string]string
+	HostPublic  string
+	HostPrivate string
+}
+
+func (cfg *AssemblyParam) Render() ([]byte, error) {
+	buf := &bytes.Buffer{}
+	err := Assembly.Execute(buf, *cfg)
+	return buf.Bytes(), err
+}