Add golang.org/x/crypto/ed25519

vendor/manifest

@@ -56,6 +56,13 @@
 			"branch": "master",
 			"path": "/curve25519"
 		},
+		{
+			"importpath": "golang.org/x/crypto/ed25519",
+			"repository": "https://go.googlesource.com/crypto",
+			"revision": "81372b2fc2f10bef2a7f338da115c315a56b2726",
+			"branch": "master",
+			"path": "/ed25519"
+		},
 		{
 			"importpath": "golang.org/x/crypto/pbkdf2",
 			"repository": "https://go.googlesource.com/crypto",

vendor/src/golang.org/x/crypto/ed25519/ed25519.go

@@ -0,0 +1,181 @@
+// Copyright 2016 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.
+
+// 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 (
+	"crypto"
+	cryptorand "crypto/rand"
+	"crypto/sha512"
+	"crypto/subtle"
+	"errors"
+	"io"
+	"strconv"
+
+	"golang.org/x/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
+)
+
+// 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() crypto.PublicKey {
+	publicKey := make([]byte, PublicKeySize)
+	copy(publicKey, priv[32:])
+	return PublicKey(publicKey)
+}
+
+// Sign signs the given message with priv.
+// Ed25519 performs two passes over messages to be signed and therefore cannot
+// handle pre-hashed messages. Thus opts.HashFunc() must return zero to
+// indicate the message hasn't been hashed. This can be achieved by passing
+// crypto.Hash(0) as the value for opts.
+func (priv PrivateKey) Sign(rand io.Reader, message []byte, opts crypto.SignerOpts) (signature []byte, err error) {
+	if opts.HashFunc() != crypto.Hash(0) {
+		return nil, errors.New("ed25519: cannot sign hashed message")
+	}
+
+	return Sign(priv, message), nil
+}
+
+// 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
+}
+
+// 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
+}

vendor/src/golang.org/x/crypto/ed25519/ed25519_test.go

@@ -0,0 +1,183 @@
+// Copyright 2016 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.
+
+package ed25519
+
+import (
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"crypto"
+	"crypto/rand"
+	"encoding/hex"
+	"os"
+	"strings"
+	"testing"
+
+	"golang.org/x/crypto/ed25519/internal/edwards25519"
+)
+
+type zeroReader struct{}
+
+func (zeroReader) Read(buf []byte) (int, error) {
+	for i := range buf {
+		buf[i] = 0
+	}
+	return len(buf), nil
+}
+
+func TestUnmarshalMarshal(t *testing.T) {
+	pub, _, _ := GenerateKey(rand.Reader)
+
+	var A edwards25519.ExtendedGroupElement
+	var pubBytes [32]byte
+	copy(pubBytes[:], pub)
+	if !A.FromBytes(&pubBytes) {
+		t.Fatalf("ExtendedGroupElement.FromBytes failed")
+	}
+
+	var pub2 [32]byte
+	A.ToBytes(&pub2)
+
+	if pubBytes != pub2 {
+		t.Errorf("FromBytes(%v)->ToBytes does not round-trip, got %x\n", pubBytes, pub2)
+	}
+}
+
+func TestSignVerify(t *testing.T) {
+	var zero zeroReader
+	public, private, _ := GenerateKey(zero)
+
+	message := []byte("test message")
+	sig := Sign(private, message)
+	if !Verify(public, message, sig) {
+		t.Errorf("valid signature rejected")
+	}
+
+	wrongMessage := []byte("wrong message")
+	if Verify(public, wrongMessage, sig) {
+		t.Errorf("signature of different message accepted")
+	}
+}
+
+func TestCryptoSigner(t *testing.T) {
+	var zero zeroReader
+	public, private, _ := GenerateKey(zero)
+
+	signer := crypto.Signer(private)
+
+	publicInterface := signer.Public()
+	public2, ok := publicInterface.(PublicKey)
+	if !ok {
+		t.Fatalf("expected PublicKey from Public() but got %T", publicInterface)
+	}
+
+	if !bytes.Equal(public, public2) {
+		t.Errorf("public keys do not match: original:%x vs Public():%x", public, public2)
+	}
+
+	message := []byte("message")
+	var noHash crypto.Hash
+	signature, err := signer.Sign(zero, message, noHash)
+	if err != nil {
+		t.Fatalf("error from Sign(): %s", err)
+	}
+
+	if !Verify(public, message, signature) {
+		t.Errorf("Verify failed on signature from Sign()")
+	}
+}
+
+func TestGolden(t *testing.T) {
+	// sign.input.gz is a selection of test cases from
+	// http://ed25519.cr.yp.to/python/sign.input
+	testDataZ, err := os.Open("testdata/sign.input.gz")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer testDataZ.Close()
+	testData, err := gzip.NewReader(testDataZ)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer testData.Close()
+
+	scanner := bufio.NewScanner(testData)
+	lineNo := 0
+
+	for scanner.Scan() {
+		lineNo++
+
+		line := scanner.Text()
+		parts := strings.Split(line, ":")
+		if len(parts) != 5 {
+			t.Fatalf("bad number of parts on line %d", lineNo)
+		}
+
+		privBytes, _ := hex.DecodeString(parts[0])
+		pubKey, _ := hex.DecodeString(parts[1])
+		msg, _ := hex.DecodeString(parts[2])
+		sig, _ := hex.DecodeString(parts[3])
+		// The signatures in the test vectors also include the message
+		// at the end, but we just want R and S.
+		sig = sig[:SignatureSize]
+
+		if l := len(pubKey); l != PublicKeySize {
+			t.Fatalf("bad public key length on line %d: got %d bytes", lineNo, l)
+		}
+
+		var priv [PrivateKeySize]byte
+		copy(priv[:], privBytes)
+		copy(priv[32:], pubKey)
+
+		sig2 := Sign(priv[:], msg)
+		if !bytes.Equal(sig, sig2[:]) {
+			t.Errorf("different signature result on line %d: %x vs %x", lineNo, sig, sig2)
+		}
+
+		if !Verify(pubKey, msg, sig2) {
+			t.Errorf("signature failed to verify on line %d", lineNo)
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		t.Fatalf("error reading test data: %s", err)
+	}
+}
+
+func BenchmarkKeyGeneration(b *testing.B) {
+	var zero zeroReader
+	for i := 0; i < b.N; i++ {
+		if _, _, err := GenerateKey(zero); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkSigning(b *testing.B) {
+	var zero zeroReader
+	_, priv, err := GenerateKey(zero)
+	if err != nil {
+		b.Fatal(err)
+	}
+	message := []byte("Hello, world!")
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Sign(priv, message)
+	}
+}
+
+func BenchmarkVerification(b *testing.B) {
+	var zero zeroReader
+	pub, priv, err := GenerateKey(zero)
+	if err != nil {
+		b.Fatal(err)
+	}
+	message := []byte("Hello, world!")
+	signature := Sign(priv, message)
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Verify(pub, message, signature)
+	}
+}