From f86c5d41f6822b158b3929599c867158c6b388f0 Mon Sep 17 00:00:00 2001
From: Pedro Albanese <68971450+pedroalbanese@users.noreply.github.com>
Date: Thu, 4 Nov 2021 08:05:23 -0300
Subject: [PATCH] SHA3 Recursive Hasher

---
 cmd/sha3sum/main.go | 191 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 191 insertions(+)
 create mode 100644 cmd/sha3sum/main.go

diff --git a/cmd/sha3sum/main.go b/cmd/sha3sum/main.go
new file mode 100644
index 0000000..5d952bd
--- /dev/null
+++ b/cmd/sha3sum/main.go
@@ -0,0 +1,191 @@
+package main
+
+import (
+	"bufio"
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"hash"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"golang.org/x/crypto/sha3"
+)
+
+var (
+	bits      = flag.Int("b", 256, "Bits: 224, 256, 384 and 512.")
+	check     = flag.String("c", "", "Check hashsum file.")
+	recursive = flag.Bool("r", false, "Process directories recursively.")
+	target    = flag.String("t", "", "Target file/wildcard to generate hashsum list.")
+	verbose   = flag.Bool("v", false, "Verbose mode. (The exit code is always 0 in this mode)")
+)
+
+func main() {
+	flag.Parse()
+
+	if (len(os.Args) < 2) || (*bits != 224 && *bits != 256 && *bits != 384 && *bits != 512) {
+		fmt.Println("SHA3 Hashsum Tool - ALBANESE Lab (c) 2020-2021\n")
+		fmt.Println("Usage of", os.Args[0]+":")
+		fmt.Printf("%s [-v] [-b N] [-c <hash.ext>] [-r] -t <file.ext>\n\n", os.Args[0])
+		flag.PrintDefaults()
+		os.Exit(1)
+	}
+
+	if *target == "-" {
+		var h hash.Hash
+		if *bits == 224 {
+			h = sha3.New224()
+		} else if *bits == 256 {
+			h = sha3.New256()
+		} else if *bits == 384 {
+			h = sha3.New384()
+		} else if *bits == 512 {
+			h = sha3.New512()
+		}
+		io.Copy(h, os.Stdin)
+		fmt.Println(hex.EncodeToString(h.Sum(nil)) + " (stdin)")
+		os.Exit(0)
+	}
+
+	if *target != "" && *recursive == false {
+		files, err := filepath.Glob(*target)
+		if err != nil {
+			log.Fatal(err)
+		}
+		for _, match := range files {
+			var h hash.Hash
+			if *bits == 224 {
+				h = sha3.New224()
+			} else if *bits == 256 {
+				h = sha3.New256()
+			} else if *bits == 384 {
+				h = sha3.New384()
+			} else if *bits == 512 {
+				h = sha3.New512()
+			}
+			f, err := os.Open(match)
+			if err != nil {
+				log.Fatal(err)
+			}
+			file, err := os.Stat(match)
+			if file.IsDir() {
+			} else {
+				if _, err := io.Copy(h, f); err != nil {
+					log.Fatal(err)
+				}
+				fmt.Println(hex.EncodeToString(h.Sum(nil)), "*"+f.Name())
+			}
+			f.Close()
+		}
+	}
+
+	if *target != "" && *recursive == true && *bits == 224 {
+		err := filepath.Walk(filepath.Dir(*target),
+			func(path string, info os.FileInfo, err error) error {
+				if err != nil {
+					return err
+				}
+				file, err := os.Stat(path)
+				if file.IsDir() {
+				} else {
+					filename := filepath.Base(path)
+					pattern := filepath.Base(*target)
+					matched, err := filepath.Match(pattern, filename)
+					if err != nil {
+						fmt.Println(err)
+					}
+					if matched {
+						var h hash.Hash
+						if *bits == 224 {
+							h = sha3.New224()
+						} else if *bits == 256 {
+							h = sha3.New256()
+						} else if *bits == 384 {
+							h = sha3.New384()
+						} else if *bits == 512 {
+							h = sha3.New512()
+						}
+						f, err := os.Open(path)
+						if err != nil {
+							log.Fatal(err)
+						}
+						if _, err := io.Copy(h, f); err != nil {
+							log.Fatal(err)
+						}
+						f.Close()
+						fmt.Println(hex.EncodeToString(h.Sum(nil)), "*"+f.Name())
+					}
+				}
+				return nil
+			})
+		if err != nil {
+			log.Println(err)
+		}
+	}
+
+	if *check != "" {
+		var file io.Reader
+		var err error
+		if *check == "-" {
+			file = os.Stdin
+		} else {
+			file, err = os.Open(*check)
+			if err != nil {
+				log.Fatalf("failed opening file: %s", err)
+			}
+		}
+		scanner := bufio.NewScanner(file)
+		scanner.Split(bufio.ScanLines)
+		var txtlines []string
+
+		for scanner.Scan() {
+			txtlines = append(txtlines, scanner.Text())
+		}
+		for _, eachline := range txtlines {
+			lines := strings.Split(string(eachline), " *")
+			if strings.Contains(string(eachline), " *") {
+				var h hash.Hash
+				if *bits == 224 {
+					h = sha3.New224()
+				} else if *bits == 256 {
+					h = sha3.New256()
+				} else if *bits == 384 {
+					h = sha3.New384()
+				} else if *bits == 512 {
+					h = sha3.New512()
+				}
+				_, err := os.Stat(lines[1])
+				if err == nil {
+					f, err := os.Open(lines[1])
+					if err != nil {
+						log.Fatal(err)
+					}
+					io.Copy(h, f)
+					f.Close()
+
+					if *verbose {
+						if hex.EncodeToString(h.Sum(nil)) == lines[0] {
+							fmt.Println(lines[1]+"\t", "OK")
+						} else {
+							fmt.Println(lines[1]+"\t", "FAILED")
+						}
+					} else {
+						if hex.EncodeToString(h.Sum(nil)) == lines[0] {
+						} else {
+							os.Exit(1)
+						}
+					}
+				} else {
+					if *verbose {
+						fmt.Println(lines[1]+"\t", "Not found!")
+					} else {
+						os.Exit(1)
+					}
+				}
+			}
+		}
+	}
+}