+++ /dev/null
-// Package ed25519 implements the Ed25519 signature algorithm. See
-// http://ed25519.cr.yp.to/.
-//
-// These functions are also compatible with the “Ed25519” function defined in
-// https://tools.ietf.org/html/draft-irtf-cfrg-eddsa-05.
-package ed25519
-
-// This code is a port of the public domain, “ref10” implementation of ed25519
-// from SUPERCOP.
-
-import (
- cryptorand "crypto/rand"
- "crypto/sha512"
- "crypto/subtle"
- "encoding/hex"
- "io"
- "strconv"
-
- "github.com/bytom/bytom/crypto/ed25519/internal/edwards25519"
-)
-
-const (
- // PublicKeySize is the size, in bytes, of public keys as used in this package.
- PublicKeySize = 32
- // PrivateKeySize is the size, in bytes, of private keys as used in this package.
- PrivateKeySize = 64
- // SignatureSize is the size, in bytes, of signatures generated and verified by this package.
- SignatureSize = 64
- // SeedSize is the size, in bytes, of private key seeds. These are the private key representations used by RFC 8032.
- SeedSize = 32
-)
-
-// PublicKey is the type of Ed25519 public keys.
-type PublicKey []byte
-
-// PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
-type PrivateKey []byte
-
-// Public returns the PublicKey corresponding to priv.
-func (priv PrivateKey) Public() PublicKey {
- publicKey := make([]byte, PublicKeySize)
- copy(publicKey, priv[32:])
- return PublicKey(publicKey)
-}
-
-// Seed returns the private key seed corresponding to priv. It is provided for
-// interoperability with RFC 8032. RFC 8032's private keys correspond to seeds
-// in this package.
-func (priv PrivateKey) Seed() []byte {
- seed := make([]byte, SeedSize)
- copy(seed, priv[:32])
- return seed
-}
-
-func (priv PrivateKey) String() string {
- return hex.EncodeToString(priv)
-}
-
-// GenerateKey generates a public/private key pair using entropy from rand.
-// If rand is nil, crypto/rand.Reader will be used.
-func GenerateKey(rand io.Reader) (publicKey PublicKey, privateKey PrivateKey, err error) {
- if rand == nil {
- rand = cryptorand.Reader
- }
-
- privateKey = make([]byte, PrivateKeySize)
- publicKey = make([]byte, PublicKeySize)
- _, err = io.ReadFull(rand, privateKey[:32])
- if err != nil {
- return nil, nil, err
- }
-
- digest := sha512.Sum512(privateKey[:32])
- digest[0] &= 248
- digest[31] &= 127
- digest[31] |= 64
-
- var A edwards25519.ExtendedGroupElement
- var hBytes [32]byte
- copy(hBytes[:], digest[:])
- edwards25519.GeScalarMultBase(&A, &hBytes)
- var publicKeyBytes [32]byte
- A.ToBytes(&publicKeyBytes)
-
- copy(privateKey[32:], publicKeyBytes[:])
- copy(publicKey, publicKeyBytes[:])
-
- return publicKey, privateKey, nil
-}
-
-// NewKeyFromSeed calculates a private key from a seed. It will panic if
-// len(seed) is not SeedSize. This function is provided for interoperability
-// with RFC 8032. RFC 8032's private keys correspond to seeds in this
-// package.
-func NewKeyFromSeed(seed []byte) PrivateKey {
- if l := len(seed); l != SeedSize {
- panic("ed25519: bad seed length: " + strconv.Itoa(l))
- }
-
- digest := sha512.Sum512(seed)
- digest[0] &= 248
- digest[31] &= 127
- digest[31] |= 64
-
- var A edwards25519.ExtendedGroupElement
- var hBytes [32]byte
- copy(hBytes[:], digest[:])
- edwards25519.GeScalarMultBase(&A, &hBytes)
- var publicKeyBytes [32]byte
- A.ToBytes(&publicKeyBytes)
-
- privateKey := make([]byte, PrivateKeySize)
- copy(privateKey, seed)
- copy(privateKey[32:], publicKeyBytes[:])
-
- return privateKey
-}
-
-// Sign signs the message with privateKey and returns a signature. It will
-// panic if len(privateKey) is not PrivateKeySize.
-func Sign(privateKey PrivateKey, message []byte) []byte {
- if l := len(privateKey); l != PrivateKeySize {
- panic("ed25519: bad private key length: " + strconv.Itoa(l))
- }
-
- h := sha512.New()
- h.Write(privateKey[:32])
-
- var digest1, messageDigest, hramDigest [64]byte
- var expandedSecretKey [32]byte
- h.Sum(digest1[:0])
- copy(expandedSecretKey[:], digest1[:])
- expandedSecretKey[0] &= 248
- expandedSecretKey[31] &= 63
- expandedSecretKey[31] |= 64
-
- h.Reset()
- h.Write(digest1[32:])
- h.Write(message)
- h.Sum(messageDigest[:0])
-
- var messageDigestReduced [32]byte
- edwards25519.ScReduce(&messageDigestReduced, &messageDigest)
- var R edwards25519.ExtendedGroupElement
- edwards25519.GeScalarMultBase(&R, &messageDigestReduced)
-
- var encodedR [32]byte
- R.ToBytes(&encodedR)
-
- h.Reset()
- h.Write(encodedR[:])
- h.Write(privateKey[32:])
- h.Write(message)
- h.Sum(hramDigest[:0])
- var hramDigestReduced [32]byte
- edwards25519.ScReduce(&hramDigestReduced, &hramDigest)
-
- var s [32]byte
- edwards25519.ScMulAdd(&s, &hramDigestReduced, &expandedSecretKey, &messageDigestReduced)
-
- signature := make([]byte, SignatureSize)
- copy(signature[:], encodedR[:])
- copy(signature[32:], s[:])
-
- return signature
-}
-
-// Verify reports whether sig is a valid signature of message by publicKey. It
-// will panic if len(publicKey) is not PublicKeySize.
-func Verify(publicKey PublicKey, message, sig []byte) bool {
- if l := len(publicKey); l != PublicKeySize {
- panic("ed25519: bad public key length: " + strconv.Itoa(l))
- }
-
- if len(sig) != SignatureSize || sig[63]&224 != 0 {
- return false
- }
-
- var A edwards25519.ExtendedGroupElement
- var publicKeyBytes [32]byte
- copy(publicKeyBytes[:], publicKey)
- if !A.FromBytes(&publicKeyBytes) {
- return false
- }
- edwards25519.FeNeg(&A.X, &A.X)
- edwards25519.FeNeg(&A.T, &A.T)
-
- h := sha512.New()
- h.Write(sig[:32])
- h.Write(publicKey[:])
- h.Write(message)
- var digest [64]byte
- h.Sum(digest[:0])
-
- var hReduced [32]byte
- edwards25519.ScReduce(&hReduced, &digest)
-
- var R edwards25519.ProjectiveGroupElement
- var b [32]byte
- copy(b[:], sig[32:])
- edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &b)
-
- var checkR [32]byte
- R.ToBytes(&checkR)
- return subtle.ConstantTimeCompare(sig[:32], checkR[:]) == 1
-}
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