From db1754452806598545038fb78deae6788cae2af8 Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Sat, 25 Sep 2021 23:49:40 +0300
Subject: [PATCH] BLAKE2b-256-aware -fsck

---
 integrity.go | 80 +++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 58 insertions(+), 22 deletions(-)

diff --git a/integrity.go b/integrity.go
index 1e0dddd..84011fe 100644
--- a/integrity.go
+++ b/integrity.go
@@ -18,25 +18,61 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 package main
 
 import (
+	"bufio"
 	"bytes"
 	"crypto/sha256"
 	"fmt"
+	"hash"
+	"io"
 	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
 	"strings"
+
+	"golang.org/x/crypto/blake2b"
 )
 
+func checkFile(
+	pkgName, fn, fnHash, hasherName string,
+	hasher hash.Hash, digest []byte,
+) bool {
+	expected, err := ioutil.ReadFile(fnHash)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fd, err := os.Open(fn)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return true
+		}
+		log.Fatal(err)
+	}
+	_, err = io.Copy(hasher, bufio.NewReader(fd))
+	fd.Close()
+	if err != nil {
+		log.Fatal(err)
+	}
+	isEqual := bytes.Compare(hasher.Sum(digest[:0]), expected) == 0
+	hasher.Reset()
+	if isEqual {
+		fmt.Println("GOOD", hasherName, pkgName)
+		return true
+	}
+	fmt.Println("BAD", hasherName, pkgName)
+	return false
+}
+
 func goodIntegrity() bool {
 	dirs, err := ioutil.ReadDir(*Root)
 	if err != nil {
 		log.Fatal(err)
 	}
-	hasher := sha256.New()
-	digest := make([]byte, sha256.Size)
+	hasherSHA256 := sha256.New()
+	hasherBLAKE2b256 := blake2b256New()
+	digestSHA256 := make([]byte, sha256.Size)
+	digestBLAKE2b256 := make([]byte, blake2b.Size256)
 	isGood := true
-	var data []byte
 	var pkgName string
 	for _, dir := range dirs {
 		files, err := ioutil.ReadDir(filepath.Join(*Root, dir.Name()))
@@ -44,29 +80,29 @@ func goodIntegrity() bool {
 			log.Fatal(err)
 		}
 		for _, file := range files {
-			if !strings.HasSuffix(file.Name(), "."+HashAlgoSHA256) {
+			if strings.HasSuffix(file.Name(), "."+HashAlgoSHA256) {
+				pkgName = strings.TrimSuffix(file.Name(), "."+HashAlgoSHA256)
+				if !checkFile(
+					pkgName,
+					filepath.Join(*Root, dir.Name(), pkgName),
+					filepath.Join(*Root, dir.Name(), file.Name()),
+					"SHA256", hasherSHA256, digestSHA256,
+				) {
+					isGood = false
+				}
 				continue
 			}
-			pkgName = strings.TrimSuffix(file.Name(), "."+HashAlgoSHA256)
-			data, err = ioutil.ReadFile(filepath.Join(*Root, dir.Name(), pkgName))
-			if err != nil {
-				if os.IsNotExist(err) {
-					continue
+			if strings.HasSuffix(file.Name(), "."+HashAlgoBLAKE2b256) {
+				pkgName = strings.TrimSuffix(file.Name(), "."+HashAlgoBLAKE2b256)
+				if !checkFile(
+					pkgName,
+					filepath.Join(*Root, dir.Name(), pkgName),
+					filepath.Join(*Root, dir.Name(), file.Name()),
+					"BLAKE2b-256", hasherBLAKE2b256, digestBLAKE2b256,
+				) {
+					isGood = false
 				}
-				log.Fatal(err)
-			}
-			hasher.Write(data)
-			data, err = ioutil.ReadFile(filepath.Join(*Root, dir.Name(), file.Name()))
-			if err != nil {
-				log.Fatal(err)
-			}
-			if bytes.Compare(hasher.Sum(digest[:0]), data) == 0 {
-				fmt.Println("GOOD", pkgName)
-			} else {
-				isGood = false
-				fmt.Println("BAD", pkgName)
 			}
-			hasher.Reset()
 		}
 	}
 	return isGood
-- 
2.44.0