add more algo

commands/sha3/sha3.go

@@ -0,0 +1,84 @@
+package sha3
+
+import (
+	"context"
+	"crypto/sha3"
+	"flag"
+	"fmt"
+	"hash_utils/tools"
+	"os"
+	"strings"
+
+	"github.com/google/subcommands"
+)
+
+type (
+	SHA3Cmd struct {
+		file   string
+		length int
+	}
+)
+
+func (*SHA3Cmd) Name() string     { return "sha3" }
+func (*SHA3Cmd) Synopsis() string { return "" }
+func (*SHA3Cmd) Usage() string {
+	return `Usage: hash_utils sha2
+
+Options:
+`
+}
+
+func (p *SHA3Cmd) SetFlags(f *flag.FlagSet) {
+	f.StringVar(&p.file, "file", "", "get the checksum of a file")
+	f.IntVar(&p.length, "length", 256, "change the length, supported length is 224, 256, 384 and 512")
+}
+
+func (p *SHA3Cmd) Execute(_ context.Context, f *flag.FlagSet, _ ...interface{}) subcommands.ExitStatus {
+	h, err := parseBitLength(p.length)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, "error:", err)
+		return subcommands.ExitUsageError
+	}
+	if len(p.file) > 0 {
+		file, err := os.OpenFile(p.file, os.O_RDONLY, 0)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "error: failed to open the file:", err)
+			return subcommands.ExitFailure
+		}
+		defer file.Close()
+
+		h, err := tools.Hash(h, file)
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "error:", err)
+			return subcommands.ExitFailure
+		}
+		fmt.Printf("%s: %s\n", f.Name(), h)
+
+		return subcommands.ExitSuccess
+	}
+
+	for _, arg := range f.Args() {
+		h, err := tools.Hash(h, strings.NewReader(arg))
+		if err != nil {
+			fmt.Fprintln(os.Stderr, "error:", err)
+			return subcommands.ExitFailure
+		}
+		fmt.Printf("%s: %s\n", arg, h)
+	}
+
+	return subcommands.ExitSuccess
+}
+
+func parseBitLength(length int) (*sha3.SHA3, error) {
+	switch length {
+	case 224:
+		return sha3.New224(), nil
+	case 256:
+		return sha3.New256(), nil
+	case 384:
+		return sha3.New384(), nil
+	case 512:
+		return sha3.New512(), nil
+	}
+	return nil, fmt.Errorf("invalid length: supported length is 224, 256, 384 and 512")
+}