notary/internal/notecheck: check go.sum against notary
This is part of a design sketch for a Go module notary.
Eventually the code will live outside golang.org/x/exp.
Everything here is subject to change! Don't depend on it!
This is a demo of using the notary URL endpoints
to validate go.sum entries. The real implementation
in cmd/go would cache both the tree head and
downloaded tiles.
Change-Id: I6715cbe40e07fbab0c5cb9ab20e366195b66e6da
Reviewed-on: https://go-review.googlesource.com/c/exp/+/162899
Run-TryBot: Russ Cox <rsc@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
diff --git a/notary/internal/notecheck/main.go b/notary/internal/notecheck/main.go
new file mode 100644
index 0000000..1c933aa
--- /dev/null
+++ b/notary/internal/notecheck/main.go
@@ -0,0 +1,260 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Notecheck checks a go.sum file against a notary.
+//
+// WARNING! This program is meant as a proof of concept demo and
+// should not be used in production scripts.
+// It does not set an exit status to report whether the
+// checksums matched, and it does not filter the go.sum
+// according to the $GONOVERIFY environment variable.
+//
+// Usage:
+//
+// notecheck [-v] notary-key go.sum
+//
+// The -v flag enables verbose output.
+//
+package main
+
+import (
+ "bytes"
+ "encoding/hex"
+ "flag"
+ "fmt"
+ "io/ioutil"
+ "log"
+ "net/http"
+ "os"
+ "strconv"
+ "strings"
+ "sync"
+ "time"
+
+ "golang.org/x/exp/notary/internal/note"
+ "golang.org/x/exp/notary/internal/tlog"
+)
+
+func usage() {
+ fmt.Fprintf(os.Stderr, "usage: notecheck [-u url] [-h H] [-v] notary-key go.sum...\n")
+ os.Exit(2)
+}
+
+var height = flag.Int("h", 2, "tile height")
+var vflag = flag.Bool("v", false, "enable verbose output")
+var url = flag.String("u", "", "url to notary (overriding name)")
+
+func main() {
+ log.SetPrefix("notecheck: ")
+ log.SetFlags(0)
+
+ flag.Usage = usage
+ flag.Parse()
+ if flag.NArg() < 2 {
+ usage()
+ }
+
+ vkey := flag.Arg(0)
+ verifier, err := note.NewVerifier(vkey)
+ if err != nil {
+ log.Fatal(err)
+ }
+ if *url == "" {
+ *url = "https://" + verifier.Name()
+ }
+ msg, err := httpGet(*url + "/latest")
+ if err != nil {
+ log.Fatal(err)
+ }
+ treeNote, err := note.Open(msg, note.NotaryList(verifier))
+ if err != nil {
+ log.Fatalf("reading note: %v\nnote:\n%s", err, msg)
+ }
+ tree, err := tlog.ParseTree([]byte(treeNote.Text))
+ if err != nil {
+ log.Fatal(err)
+ }
+
+ if *vflag {
+ log.Printf("validating against %s @%d", verifier.Name(), tree.N)
+ }
+
+ verifierURL := *url
+ tr := &tileReader{url: verifierURL + "/"}
+ thr := tlog.TileHashReader(tree, tr)
+ if _, err := tlog.TreeHash(tree.N, thr); err != nil {
+ log.Fatal(err)
+ }
+
+ for _, arg := range flag.Args()[1:] {
+ data, err := ioutil.ReadFile(arg)
+ if err != nil {
+ log.Fatal(err)
+ }
+ log.SetPrefix("notecheck: " + arg + ": ")
+ checkGoSum(data, verifierURL, thr)
+ log.SetPrefix("notecheck: ")
+ }
+}
+
+func checkGoSum(data []byte, verifierURL string, thr tlog.HashReader) {
+ lines := strings.SplitAfter(string(data), "\n")
+ if lines[len(lines)-1] != "" {
+ log.Printf("error: final line missing newline")
+ return
+ }
+ lines = lines[:len(lines)-1]
+ if len(lines)%2 != 0 {
+ log.Printf("error: odd number of lines")
+ }
+ for i := 0; i+2 <= len(lines); i += 2 {
+ f1 := strings.Fields(lines[i])
+ f2 := strings.Fields(lines[i+1])
+ if len(f1) != 3 || len(f2) != 3 || f1[0] != f2[0] || f1[1]+"/go.mod" != f2[1] {
+ log.Printf("error: bad line pair:\n\t%s\t%s", lines[i], lines[i+1])
+ continue
+ }
+
+ data, err := httpGet(verifierURL + "/lookup/" + f1[0] + "@" + f1[1])
+ if err != nil {
+ log.Printf("%s@%s: %v", f1[0], f1[1], err)
+ continue
+ }
+ j := bytes.IndexByte(data, '\n')
+ if j < 0 {
+ log.Printf("%s@%s: short response from lookup", f1[0], f1[1])
+ continue
+ }
+ id, err := strconv.ParseInt(strings.TrimSpace(string(data[:j])), 10, 64)
+ if err != nil {
+ log.Printf("%s@%s: unexpected response:\n%s", f1[0], f1[1], data)
+ continue
+ }
+ ldata := data[j+1:]
+
+ c := make(chan *tlog.Hash, 1)
+ go func() {
+ hashes, err := thr.ReadHashes([]int64{tlog.StoredHashIndex(0, id)})
+ if err != nil {
+ log.Printf("%s@%s: %v", f1[0], f1[1], err)
+ c <- nil
+ return
+ }
+ c <- &hashes[0]
+ }()
+
+ // The record lookup can be skipped in favor of using the /lookup response
+ // but we fetch record and test that they match, to check the server.
+ data, err = httpGet(verifierURL + "/record/" + fmt.Sprint(id))
+ if err != nil {
+ log.Printf("%s@%s: %v", f1[0], f1[1], err)
+ continue
+ }
+ if !bytes.Equal(data, ldata) {
+ log.Printf("%s@%s: different data from lookup and record:\n%s\n%s", hex.Dump(ldata), hex.Dump(data))
+ continue
+ }
+
+ hash := tlog.RecordHash(data)
+ hash1 := <-c
+ if hash1 == nil {
+ continue
+ }
+ if *hash1 != hash {
+ log.Printf("%s@%s: inconsistent records on notary!", f1[0], f1[1])
+ continue
+ }
+ if string(data) != lines[i]+lines[i+1] {
+ log.Printf("%s@%s: invalid go.sum entries:\nhave:\n\t%s\t%swant:\n\t%s", f1[0], f1[1], lines[i], lines[i+1], strings.Replace(string(data), "\n", "\n\t", -1))
+ }
+ }
+}
+
+func init() {
+ http.DefaultClient.Timeout = 10 * time.Second
+}
+
+func httpGet(url string) ([]byte, error) {
+ start := time.Now()
+ resp, err := http.Get(url)
+ if err != nil {
+ return nil, err
+ }
+ defer resp.Body.Close()
+ if resp.StatusCode != 200 {
+ return nil, fmt.Errorf("GET %v: %v", url, resp.Status)
+ }
+ data, err := ioutil.ReadAll(resp.Body)
+ if err != nil {
+ return nil, err
+ }
+ if *vflag {
+ fmt.Fprintf(os.Stderr, "%.3fs %s\n", time.Since(start).Seconds(), url)
+ }
+ return data, nil
+}
+
+type tileReader struct {
+ url string
+ cache map[tlog.Tile][]byte
+ cacheMu sync.Mutex
+}
+
+func (r *tileReader) Height() int {
+ return *height
+}
+
+func (r *tileReader) Reject(tile tlog.Tile) {
+ log.Printf("tile rejected: %v", tile.Path())
+}
+
+// TODO(rsc): Move some variant of this to package tlog
+// once we are more sure of the API.
+
+func (r *tileReader) ReadTiles(tiles []tlog.Tile) ([][]byte, error) {
+ var wg sync.WaitGroup
+ out := make([][]byte, len(tiles))
+ errs := make([]error, len(tiles))
+ r.cacheMu.Lock()
+ if r.cache == nil {
+ r.cache = make(map[tlog.Tile][]byte)
+ }
+ for i, tile := range tiles {
+ if data := r.cache[tile]; data != nil {
+ out[i] = data
+ continue
+ }
+ wg.Add(1)
+ go func(i int, tile tlog.Tile) {
+ defer wg.Done()
+ data, err := httpGet(r.url + tile.Path())
+ if err != nil && tile.W != 1<<uint(tile.H) {
+ fullTile := tile
+ fullTile.W = 1 << uint(tile.H)
+ if fullData, err1 := httpGet(r.url + fullTile.Path()); err1 == nil {
+ data = fullData[:tile.W*tlog.HashSize]
+ err = nil
+ }
+ }
+ if err != nil {
+ errs[i] = err
+ return
+ }
+ r.cacheMu.Lock()
+ r.cache[tile] = data
+ r.cacheMu.Unlock()
+ out[i] = data
+ }(i, tile)
+ }
+ r.cacheMu.Unlock()
+ wg.Wait()
+
+ for _, err := range errs {
+ if err != nil {
+ return nil, err
+ }
+ }
+
+ return out, nil
+}
diff --git a/notary/internal/notecheck/test.bash b/notary/internal/notecheck/test.bash
new file mode 100755
index 0000000..d1944a7
--- /dev/null
+++ b/notary/internal/notecheck/test.bash
@@ -0,0 +1,6 @@
+#!/bin/bash
+
+set -e
+go build -o notecheck.exe
+./notecheck.exe "$@" -v rsc-goog.appspot.com+eecb1dec+AbTy1QXWdqYd1TTpuaUqsk6u7p+n4AqLiLB8SBwoB831 test.sum
+rm -f ./notecheck.exe
diff --git a/notary/internal/notecheck/test.sum b/notary/internal/notecheck/test.sum
new file mode 100644
index 0000000..4a8bcd7
--- /dev/null
+++ b/notary/internal/notecheck/test.sum
@@ -0,0 +1,6 @@
+golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c h1:qgOY6WgZOaTkIIMiVjBQcw93ERBE4m30iBm00nkL0i8=
+golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+rsc.io/quote v1.5.2 h1:w5fcysjrx7yqtD/aO+QwRjYZOKnaM9Uh2b40tElTs3Y=
+rsc.io/quote v1.5.2/go.mod h1:LzX7hefJvL54yjefDEDHNONDjII0t9xZLPXsUe+TKr0=
+rsc.io/sampler v1.3.0 h1:7uVkIFmeBqHfdjD+gZwtXXI+RODJ2Wc4O7MPEh/QiW4=
+rsc.io/sampler v1.3.0/go.mod h1:T1hPZKmBbMNahiBKFy5HrXp6adAjACjK9JXDnKaTXpA=
