text: // Copyright 2019 The Go Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style
  // license that can be found in the LICENSE file.
  
  // +build go1.13
  
  // Package ed25519 implements the Ed25519 signature algorithm. See
  // https://ed25519.cr.yp.to/.
  //
  // These functions are also compatible with the “Ed25519” function defined in
  // RFC 8032. However, unlike RFC 8032's formulation, this package's private key
  // representation includes a public key suffix to make multiple signing
  // operations with the same key more efficient. This package refers to the RFC
  // 8032 private key as the “seed”.
  //
  // Beginning with Go 1.13, the functionality of this package was moved to the
  // standard library as crypto/ed25519. This package only acts as a compatibility
  // wrapper.
  package ed25519
  
  import (
  	"crypto/ed25519"
  	"io"
  )
  
  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.
  //
  // This type is an alias for crypto/ed25519's PublicKey type.
  // See the crypto/ed25519 package for the methods on this type.
  type PublicKey = ed25519.PublicKey
  
  // PrivateKey is the type of Ed25519 private keys. It implements crypto.Signer.
  //
  // This type is an alias for crypto/ed25519's PrivateKey type.
  // See the crypto/ed25519 package for the methods on this type.
  type PrivateKey = ed25519.PrivateKey
  
  // 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, PrivateKey, error) {
  	return ed25519.GenerateKey(rand)
  }
  
  // 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 {
  	return ed25519.NewKeyFromSeed(seed)
  }
  
  // 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 {
  	return ed25519.Sign(privateKey, message)
  }
  
  // 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 {
  	return ed25519.Verify(publicKey, message, sig)
  }
  