Add drafty assemble command

1 files changed, 280 insertions, 2 deletions

diff --git a/cmd_assemble.go b/cmd_assemble.go
index 246ba6e..f084193 100644
--- a/cmd_assemble.go
+++ b/cmd_assemble.go
@@ -1,7 +1,285 @@
 package main
 
-import "fmt"
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	logger "log"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+	"time"
+
+	"git.cs.kau.se/rasmoste/ct-sans/internal/sanitize"
+	ct "github.com/google/certificate-transparency-go"
+	"gitlab.torproject.org/rgdd/ct/pkg/metadata"
+)
 
 func assemble(opts options) error {
-	return fmt.Errorf("TODO")
+	now := time.Now()
+	metadataBytes, err := os.ReadFile(fmt.Sprintf("%s/%s", opts.Directory, opts.metadataFile))
+	if err != nil {
+		return err
+	}
+	var md metadata.Metadata
+	if err := json.Unmarshal(metadataBytes, &md); err != nil {
+		return err
+	}
+	var files []string
+	var sths []ct.SignedTreeHead
+	for _, log := range logs(md) {
+		id, _ := log.Key.ID()
+		th, err := readState(opts, id[:])
+		if err != nil {
+			return err
+		}
+		sth, err := readSnapshot(opts, id[:])
+		if err != nil {
+			return err
+		}
+		if uint64(th.TreeSize) != sth.TreeSize {
+			return fmt.Errorf("%s: at tree size %d, want %d", *log.Description, th.TreeSize, sth.TreeSize)
+		}
+		if th.RootHash != sth.SHA256RootHash {
+			return fmt.Errorf("%s: root hash mismatch")
+		}
+
+		files = append(files, fmt.Sprintf("%s/%x/%s", opts.logDirectory, id[:], opts.sansFile))
+		sths = append(sths, sth)
+	}
+
+	logger.Printf("INFO: merging and de-duplicating %d input files with GNU sort", len(files))
+	archiveDir := fmt.Sprintf("%s/%s-ct-sans", opts.archiveDirectory, now.Format("2006-01-02"))
+	if err := os.MkdirAll(archiveDir, os.ModePerm); err != nil {
+		return err
+	}
+	sansFile := fmt.Sprintf("%s/%s", archiveDir, opts.sansFile)
+	if err := dedup(opts, sansFile, files); err != nil {
+		return err
+	}
+	size, err := fileSize(sansFile)
+	if err != nil {
+		return err
+	}
+	logger.Printf("INFO: created %s (%s)", sansFile, size)
+
+	logger.Printf("INFO: sanitizing SANs to visit")
+	visitFile := fmt.Sprintf("%s/%s", archiveDir, opts.visitFile)
+	skip, tweak, err := sanitizeSANs(sansFile, visitFile)
+	if err != nil {
+		return err
+	}
+	logger.Printf("INFO: ruled out %d lines while sanitizing domains", skip)
+	logger.Printf("INFO: tweaked %d domains with \"*.\" prefixes", tweak)
+	logger.Printf("INFO: created %s", visitFile)
+
+	logger.Printf("INFO: de-duplicating %s with GNU sort", visitFile)
+	wipFile := fmt.Sprintf("%s.tmp", visitFile)
+	if err := dedup(opts, wipFile, []string{visitFile}); err != nil {
+		return err
+	}
+	if err := os.Rename(wipFile, visitFile); err != nil {
+		return err
+	}
+	if size, err = fileSize(visitFile); err != nil {
+		return err
+	}
+	logger.Printf("INFO: %s is down to %s", visitFile, size)
+
+	logger.Printf("INFO: adding README")
+	readme, err := makeREADME(opts, sths, skip, tweak, now)
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(fmt.Sprintf("%s/README.md", archiveDir), []byte(readme), 0644); err != nil {
+		return err
+	}
+
+	logger.Printf("INFO: adding signed metadata file")
+	sigBytes, err := os.ReadFile(fmt.Sprintf("%s/%s", opts.Directory, opts.metadataSignatureFile))
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(fmt.Sprintf("%s/%s", archiveDir, opts.metadataFile), metadataBytes, 0644); err != nil {
+		return err
+	}
+	if err := os.WriteFile(fmt.Sprintf("%s/%s", archiveDir, opts.metadataSignatureFile), sigBytes, 0644); err != nil {
+		return err
+	}
+
+	logger.Printf("INFO: adding signed tree heads")
+	sthsBytes, err := json.MarshalIndent(sths, "", "\t")
+	if err != nil {
+		return err
+	}
+	if err := os.WriteFile(fmt.Sprintf("%s/sths.json", archiveDir), sthsBytes, 0644); err != nil {
+		return err
+	}
+
+	logger.Printf("INFO: uncompressed dataset available in %s", archiveDir)
+	return nil
+}
+
+func dedup(opts options, outputFile string, inputFiles []string) error {
+	cmd := exec.Command("sort", append([]string{
+		"-Vuo", outputFile,
+		"--buffer-size", fmt.Sprintf("%dG", opts.BufferSize),
+		"--temporary-directory", fmt.Sprintf("%s", opts.TempDir),
+		"--parallel", fmt.Sprintf("%d", opts.Parallel),
+	}, inputFiles...)...)
+	if errors.Is(cmd.Err, exec.ErrDot) {
+		cmd.Err = nil
+	}
+	stderr := bytes.NewBuffer(nil)
+	cmd.Stderr = stderr
+	if _, err := cmd.Output(); err != nil {
+		return fmt.Errorf("%s", string(stderr.Bytes()))
+	}
+	return nil
+}
+
+func sanitizeSANs(sansFile, visitFile string) (int, int, error) {
+	fpSANs, err := os.OpenFile(sansFile, os.O_RDONLY, 0644)
+	if err != nil {
+		return 0, 0, err
+	}
+	defer fpSANs.Close()
+	scanner := bufio.NewScanner(fpSANs)
+	max := 128 * 1024 * 1024
+	buf := make([]byte, 0, max)
+	scanner.Buffer(buf, max)
+
+	fpVisit, err := os.OpenFile(visitFile, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0644)
+	if err != nil {
+		return 0, 0, err
+	}
+	defer fpVisit.Close()
+
+	skip := 0
+	tweak := 0
+	for scanner.Scan() {
+		domain, err := sanitize.SanitizeDNSName(scanner.Text())
+		if err != nil {
+			skip += 1
+		}
+		if strings.HasPrefix(domain, "*.") {
+			tweak += 1
+			domain = domain[2:]
+		}
+		if _, err := fpVisit.WriteString(domain + "\n"); err != nil {
+			return 0, 0, err
+		}
+	}
+	if err := fpVisit.Sync(); err != nil {
+		return 0, 0, err
+	}
+	return skip, tweak, nil
+}
+
+func makeREADME(opts options, sths []ct.SignedTreeHead, skip, tweak int, now time.Time) (string, error) {
+	snapshotTime, err := readSnapshotTime(opts)
+	if err != nil {
+		return "", err
+	}
+
+	noticeFile := opts.Directory + "/" + opts.noticeFile
+	notice, err := noticeReport(noticeFile)
+	if err != nil {
+		// TODO: start writing notice prints to a separate file in data/
+		// by default, then make this a hard error.  This needs to be
+		// done manually now by grepping for NOTICE in collect.stdout.
+		logger.Printf("WARNING: could not find notice file, skipping")
+		notice = "UNKNOWN"
+	} else {
+		// TODO: save notice file
+	}
+
+	return fmt.Sprintf(`# ct-sans dataset
+
+Dataset assembled at %s.  Contents:
+
+  - README.md
+  - metadata.json
+  - metadata.sig
+  - sths.json
+  - sans.lst (see below)
+  - visit.lst (see below)
+  - notice.txt (see below)
+
+The signed [metadata file][] and tree heads were downloaded at %s.
+
+[metadata file]: https://groups.google.com/a/chromium.org/g/ct-policy/c/IdbrdAcDQto
+
+## sans.lst
+
+The result of downloading %d certificates from %d CT logs.
+One SAN per line.  These lines are sorted and de-duplicated.
+
+While downloading, %s certificates contained SANs that could not be parsed.
+See %s for the exact details.
+
+## visit.lst
+
+A rewrite of the sans.lst dataset to be more suitable for visits:
+
+  - Leading and trailing white space is removed
+  - Trailing dots are removed
+  - The prefixes "http://" and "https://" are removed
+  - Lines that contain non-printable ASCII characters are dropped.  The
+    definition of a printable ascii character is '\t' and numerical values
+    32-126.  In total, %d lines were dropped.
+  - Make wildcard domains into normal domains by removing the first two bytes.
+    In total, %d lines were rewritten like this.
+
+`, now.Format(time.UnixDate), snapshotTime.Format(time.UnixDate), numCertificates(sths), len(sths), notice, noticeFile, skip, tweak), nil
+}
+
+func fileSize(name string) (string, error) {
+	fi, err := os.Stat(name)
+	if err != nil {
+		return "", err
+	}
+	size := fmt.Sprintf("%.1f GiB", float64(fi.Size())/float64((1024*1024*1024)))
+	if fi.Size() < 1024*1024*1024 {
+		size = fmt.Sprintf("%.1f MiB", float64(fi.Size())/float64((1024*1024)))
+	}
+	return size, nil
+}
+
+func noticeReport(path string) (string, error) {
+	fp, err := os.OpenFile(path, os.O_RDONLY, 0644)
+	if err != nil {
+		return "", err
+	}
+	defer fp.Close()
+
+	scanner := bufio.NewScanner(fp)
+	num := 0
+	for scanner.Scan() {
+		_ = scanner.Text()
+		num += 1
+	}
+	return fmt.Sprintf("%d", num), nil
+}
+
+func numCertificates(sths []ct.SignedTreeHead) (sum uint64) {
+	for _, sth := range sths {
+		sum += sth.TreeSize
+	}
+	return
+}
+
+func readSnapshotTime(opts options) (time.Time, error) {
+	b, err := os.ReadFile(fmt.Sprintf("%s/%s", opts.Directory, opts.metadataTimestampFile))
+	if err != nil {
+		return time.Time{}, err
+	}
+	num, err := strconv.ParseInt(string(b), 10, 64)
+	if err != nil {
+		return time.Time{}, err
+	}
+	return time.Unix(num, 0), nil
 }