package main

import (
	"crypto"
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"crypto/ed25519"

	"git.sigsum.org/sigsum-go/pkg/hex"
)

func readStdin() ([]byte, error) {
	b, err := ioutil.ReadAll(os.Stdin)
	if err != nil {
		return nil, fmt.Errorf("stdin: %v", err)
	}
	return b, nil
}

func decodeHexFromStdin() ([]byte, error) {
	b, err := readStdin()
	if err != nil {
		return nil, fmt.Errorf("failed reading stdin: %v", err)
	}
	b, err = hex.Deserialize(string(bytes.TrimSpace(b)))
	if err != nil {
		return nil, fmt.Errorf("invalid private key: %v", err)
	}
	return b, nil
}

func privFromHex(s string) (crypto.Signer, error) {
	b, err := hex.Deserialize(optPriv)
	if err != nil {
		return nil, fmt.Errorf("invalid private key: %v", err)
	}
	if len(b) != ed25519.PrivateKeySize {
		return nil, fmt.Errorf("invalid private key: size")
	}
	return ed25519.PrivateKey(b), nil
}