.gitignore

@@ -1,5 +1,3 @@
-cmd/hashcash/hashcash
-
 # ---> Go
 # Binaries for programs and plugins
 *.exe

README.md

@@ -4,39 +4,4 @@ HTTP Hashcash implemented in Go.
 
 Explanation at https://therootcompany.com/blog/http-hashcash/
 
-Go API docs at https://pkg.go.dev/git.rootprojects.org/root/hashcash?tab=doc
+Go docs at https://godoc.org/git.rootprojects.org/root/hashcash
-
-# CLI Usage
-
-Install:
-
-```bash
-go get git.rootprojects.org/root/hashcash/cmd/hashcash
-```
-
-Usage:
-
-```txt
-Usage:
-	hashcash new [subject *] [expires in 5m] [difficulty 10]
-	hashcash parse <hashcash>
-	hashcash solve <hashcash>
-	hashcash hash <hashcash>
-	hashcash verify <hashcash> [subject *]
-```
-
-Example:
-
-```bash
-my_hc=$(hashcash new)
-echo New: $my_hc
-hashcash parse "$my_hc"
-echo ""
-
-my_hc=$(hashcash solve "$my_hc")
-echo Solved: $my_hc
-hashcash parse "$my_hc"
-echo ""
-
-hashcash verify "$my_hc"
-```

cmd/hashcash/hashcash.go

@@ -1,162 +0,0 @@
-package main
-
-import (
-	"crypto/sha256"
-	"encoding/hex"
-	"encoding/json"
-	"fmt"
-	"os"
-	"strconv"
-	"time"
-
-	"git.rootprojects.org/root/hashcash"
-)
-
-func help() {
-	fmt.Println("Usage:")
-	fmt.Println("\thashcash new [subject *] [difficulty 10] [expires in 5m]")
-	fmt.Println("\thashcash parse <hashcash>")
-	fmt.Println("\thashcash solve <hashcash>")
-	fmt.Println("\thashcash hash <hashcash>")
-	fmt.Println("\thashcash verify <hashcash> [subject *]")
-}
-
-func main() {
-	args := os.Args[:]
-	nargs := len(args)
-
-	if nargs < 2 {
-		help()
-		os.Exit(1)
-		return
-	}
-
-	switch args[1] {
-	case "new":
-		var subject string
-		if nargs >= 3 {
-			subject = args[2]
-		}
-
-		var difficulty int
-		if nargs >= 4 {
-			var err error
-			difficulty, err = strconv.Atoi(args[3])
-			if nil != err {
-				help()
-				os.Exit(1)
-				return
-			}
-		}
-
-		var expIn time.Duration
-		if nargs >= 5 {
-			var err error
-			expIn, err = time.ParseDuration(args[4])
-			if nil != err {
-				fmt.Println(err)
-				help()
-				os.Exit(1)
-				return
-			}
-		} else {
-			expIn = 5 * time.Minute
-		}
-
-		h := hashcash.New(hashcash.Hashcash{
-			Subject:    subject,
-			Difficulty: difficulty,
-			ExpiresAt:  time.Now().Add(expIn),
-		})
-
-		fmt.Println(h.String())
-		return
-	case "parse":
-		var token string
-		if 3 != nargs {
-			help()
-			os.Exit(1)
-			return
-		}
-		token = args[2]
-		h, err := hashcash.Parse(token)
-		if nil != err {
-			fmt.Fprintf(os.Stderr, "%s\n", err)
-			return
-		}
-		b, _ := json.MarshalIndent(h, "", "  ")
-		fmt.Println(string(b))
-		return
-	case "solve":
-		var token string
-		if 3 != nargs {
-			help()
-			os.Exit(1)
-			return
-		}
-		token = args[2]
-		h, err := hashcash.Parse(token)
-		if nil != err {
-			fmt.Fprintf(os.Stderr, "%s\n", err)
-			os.Exit(1)
-			return
-		}
-		err = h.Solve(22)
-		if nil != err {
-			fmt.Fprintf(os.Stderr, "%s\n", err)
-			os.Exit(1)
-			return
-		}
-
-		fmt.Println(h.String())
-		return
-	case "hash":
-		var token string
-		if 3 != nargs {
-			help()
-			os.Exit(1)
-			return
-		}
-		token = args[2]
-		hash := sha256.Sum256([]byte(token))
-		fmt.Println(hex.EncodeToString(hash[:]))
-		return
-	case "verify":
-		var token string
-		if nargs < 3 {
-			help()
-			os.Exit(1)
-			return
-		}
-		token = args[2]
-		h, err := hashcash.Parse(token)
-		if nil != err {
-			fmt.Fprintf(os.Stderr, "%s\n", err)
-			return
-		}
-
-		subject := "*"
-		if nargs >= 4 {
-			subject = args[3]
-		}
-
-		err = h.Verify(subject)
-		if nil != err {
-			fmt.Fprintf(os.Stderr, "%s\n", err)
-			return
-		}
-
-		var duration string
-		dur := h.ExpiresAt.Sub(time.Now())
-		if dur > 365*24*time.Hour {
-			duration = "...a long, long time"
-		} else {
-			duration = dur.Truncate(time.Second).String()
-		}
-		fmt.Println("valid for", duration)
-		return
-	default:
-		help()
-		os.Exit(1)
-	}
-}

hashcash.go

@@ -216,10 +216,6 @@ func (h *Hashcash) Verify(subject string) error {
 }
 
 func verifyBits(hash []byte, bits, n int) bool {
-	if 0 == bits {
-		return true
-	}
-
 	for i := 0; i < n; i++ {
 		if bits > 8 {
 			bits -= 8
@@ -231,12 +227,15 @@ func verifyBits(hash []byte, bits, n int) bool {
 
 		// (bits % 8) == bits
 		pad := 8 - bits
-		if 0 == hash[i]>>pad {
+		if 0 != hash[i]>>pad {
-			return true
+			return false
-		}
 		}
 
-	return false
+		return true
+	}
+
+	// 0 == bits
+	return true
 }
 
 // Solve will search for a solution, returning an error if the difficulty is