Merge pull request #35 from c3systems/forPR

Added ECDSA; Added RSA tests; Fixed linting errors; Handling all un-handled errors

.gitignore

@@ -0,0 +1,7 @@
+.DS_Store
+
+# vim
+.swp
+*~
+*.swp
+*.swo

ecdsa.go

@@ -0,0 +1,186 @@
+package crypto
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/asn1"
+	"errors"
+	"io"
+	"math/big"
+
+	pb "github.com/libp2p/go-libp2p-crypto/pb"
+
+	sha256 "github.com/minio/sha256-simd"
+)
+
+// ECDSAPrivateKey is an implementation of an ECDSA private key
+type ECDSAPrivateKey struct {
+	priv *ecdsa.PrivateKey
+}
+
+// ECDSAPublicKey is an implementation of an ECDSA public key
+type ECDSAPublicKey struct {
+	pub *ecdsa.PublicKey
+}
+
+// ECDSASig holds the r and s values of an ECDSA signature
+type ECDSASig struct {
+	R, S *big.Int
+}
+
+var (
+	// ErrNotECDSAPubKey is returned when the public key passed is not an ecdsa public key
+	ErrNotECDSAPubKey = errors.New("not an ecdsa public key")
+	// ErrNilSig is returned when the signature is nil
+	ErrNilSig = errors.New("sig is nil")
+	// ErrNilPrivateKey is returned when a nil private key is provided
+	ErrNilPrivateKey = errors.New("private key is nil")
+	// ECDSACurve is the default ecdsa curve used
+	ECDSACurve = elliptic.P256()
+)
+
+// GenerateECDSAKeyPair generates a new ecdsa private and public key
+func GenerateECDSAKeyPair(src io.Reader) (PrivKey, PubKey, error) {
+	return GenerateECDSAKeyPairWithCurve(ECDSACurve, src)
+}
+
+// GenerateECDSAKeyPairWithCurve generates a new ecdsa private and public key with a speicified curve
+func GenerateECDSAKeyPairWithCurve(curve elliptic.Curve, src io.Reader) (PrivKey, PubKey, error) {
+	priv, err := ecdsa.GenerateKey(curve, src)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	return &ECDSAPrivateKey{priv}, &ECDSAPublicKey{&priv.PublicKey}, nil
+}
+
+// ECDSAKeyPairFromKey generates a new ecdsa private and public key from an input private key
+func ECDSAKeyPairFromKey(priv *ecdsa.PrivateKey) (PrivKey, PubKey, error) {
+	if priv == nil {
+		return nil, nil, ErrNilPrivateKey
+	}
+
+	return &ECDSAPrivateKey{priv}, &ECDSAPublicKey{&priv.PublicKey}, nil
+}
+
+// MarshalECDSAPrivateKey returns x509 bytes from a private key
+func MarshalECDSAPrivateKey(ePriv ECDSAPrivateKey) ([]byte, error) {
+	return x509.MarshalECPrivateKey(ePriv.priv)
+}
+
+// MarshalECDSAPublicKey returns x509 bytes from a public key
+func MarshalECDSAPublicKey(ePub ECDSAPublicKey) ([]byte, error) {
+	return x509.MarshalPKIXPublicKey(ePub.pub)
+}
+
+// UnmarshalECDSAPrivateKey returns a private key from x509 bytes
+func UnmarshalECDSAPrivateKey(data []byte) (PrivKey, error) {
+	priv, err := x509.ParseECPrivateKey(data)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ECDSAPrivateKey{priv}, nil
+}
+
+// UnmarshalECDSAPublicKey returns the public key from x509 bytes
+func UnmarshalECDSAPublicKey(data []byte) (PubKey, error) {
+	pubIfc, err := x509.ParsePKIXPublicKey(data)
+	if err != nil {
+		return nil, err
+	}
+
+	pub, ok := pubIfc.(*ecdsa.PublicKey)
+	if !ok {
+		return nil, ErrNotECDSAPubKey
+	}
+
+	return &ECDSAPublicKey{pub}, nil
+}
+
+// Bytes returns the private key as protobuf bytes
+func (ePriv *ECDSAPrivateKey) Bytes() ([]byte, error) {
+	return MarshalPrivateKey(ePriv)
+}
+
+// Type returns the key type
+func (ePriv *ECDSAPrivateKey) Type() pb.KeyType {
+	return pb.KeyType_ECDSA
+}
+
+// Raw returns x509 bytes from a private key
+func (ePriv *ECDSAPrivateKey) Raw() ([]byte, error) {
+	return x509.MarshalECPrivateKey(ePriv.priv)
+}
+
+// Equals compares to private keys
+func (ePriv *ECDSAPrivateKey) Equals(o Key) bool {
+	oPriv, ok := o.(*ECDSAPrivateKey)
+	if !ok {
+		return false
+	}
+
+	return ePriv.priv.D.Cmp(oPriv.priv.D) == 0
+}
+
+// Sign returns the signature of the input data
+func (ePriv *ECDSAPrivateKey) Sign(data []byte) ([]byte, error) {
+	hash := sha256.Sum256(data)
+	r, s, err := ecdsa.Sign(rand.Reader, ePriv.priv, hash[:])
+	if err != nil {
+		return nil, err
+	}
+
+	return asn1.Marshal(ECDSASig{
+		R: r,
+		S: s,
+	})
+}
+
+// GetPublic returns a public key
+func (ePriv *ECDSAPrivateKey) GetPublic() PubKey {
+	return &ECDSAPublicKey{&ePriv.priv.PublicKey}
+}
+
+// Bytes returns the public key as protobuf bytes
+func (ePub *ECDSAPublicKey) Bytes() ([]byte, error) {
+	return MarshalPublicKey(ePub)
+}
+
+// Type returns the key type
+func (ePub *ECDSAPublicKey) Type() pb.KeyType {
+	return pb.KeyType_ECDSA
+}
+
+// Raw returns x509 bytes from a public key
+func (ePub ECDSAPublicKey) Raw() ([]byte, error) {
+	return x509.MarshalPKIXPublicKey(ePub.pub)
+}
+
+// Equals compares to public keys
+func (ePub *ECDSAPublicKey) Equals(o Key) bool {
+	oPub, ok := o.(*ECDSAPublicKey)
+	if !ok {
+		return false
+	}
+
+	return ePub.pub.X != nil && ePub.pub.Y != nil && oPub.pub.X != nil && oPub.pub.Y != nil &&
+		0 == ePub.pub.X.Cmp(oPub.pub.X) && 0 == ePub.pub.Y.Cmp(oPub.pub.Y)
+}
+
+// Verify compares data to a signature
+func (ePub *ECDSAPublicKey) Verify(data, sigBytes []byte) (bool, error) {
+	sig := new(ECDSASig)
+	if _, err := asn1.Unmarshal(sigBytes, sig); err != nil {
+		return false, err
+	}
+	if sig == nil {
+		return false, ErrNilSig
+	}
+
+	hash := sha256.Sum256(data)
+
+	return ecdsa.Verify(ePub.pub, hash[:], sig.R, sig.S), nil
+}

ecdsa_test.go

@@ -0,0 +1,96 @@
+package crypto
+
+import (
+	"crypto/rand"
+	"testing"
+)
+
+func TestECDSABasicSignAndVerify(t *testing.T) {
+	priv, pub, err := GenerateECDSAKeyPair(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	data := []byte("hello! and welcome to some awesome crypto primitives")
+
+	sig, err := priv.Sign(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ok, err := pub.Verify(data, sig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !ok {
+		t.Fatal("signature didnt match")
+	}
+
+	// change data
+	data[0] = ^data[0]
+	ok, err = pub.Verify(data, sig)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if ok {
+		t.Fatal("signature matched and shouldn't")
+	}
+}
+
+func TestECDSASignZero(t *testing.T) {
+	priv, pub, err := GenerateECDSAKeyPair(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	data := make([]byte, 0)
+	sig, err := priv.Sign(data)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ok, err := pub.Verify(data, sig)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !ok {
+		t.Fatal("signature didn't match")
+	}
+}
+
+func TestECDSAMarshalLoop(t *testing.T) {
+	priv, pub, err := GenerateECDSAKeyPair(rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	privB, err := priv.Bytes()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	privNew, err := UnmarshalPrivateKey(privB)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !priv.Equals(privNew) || !privNew.Equals(priv) {
+		t.Fatal("keys are not equal")
+	}
+
+	pubB, err := pub.Bytes()
+	if err != nil {
+		t.Fatal(err)
+	}
+	pubNew, err := UnmarshalPublicKey(pubB)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !pub.Equals(pubNew) || !pubNew.Equals(pub) {
+		t.Fatal("keys are not equal")
+	}
+
+}

ed25519.go

@@ -6,17 +6,21 @@ import (
 	"io"
 
 	pb "github.com/libp2p/go-libp2p-crypto/pb"
+
 	"golang.org/x/crypto/ed25519"
 )
 
+// Ed25519PrivateKey is an ed25519 private key
 type Ed25519PrivateKey struct {
 	k ed25519.PrivateKey
 }
 
+// Ed25519PublicKey is an ed25519 public key
 type Ed25519PublicKey struct {
 	k ed25519.PublicKey
 }
 
+// GenerateEd25519Key generate a new ed25519 private and public key pair
 func GenerateEd25519Key(src io.Reader) (PrivKey, PubKey, error) {
 	pub, priv, err := ed25519.GenerateKey(src)
 	if err != nil {
@@ -36,6 +40,7 @@ func (k *Ed25519PrivateKey) Type() pb.KeyType {
 	return pb.KeyType_Ed25519
 }
 
+// Bytes marshals an ed25519 private key to protobuf bytes
 func (k *Ed25519PrivateKey) Bytes() ([]byte, error) {
 	return MarshalPrivateKey(k)
 }
@@ -55,6 +60,7 @@ func (k *Ed25519PrivateKey) pubKeyBytes() []byte {
 	return k.k[ed25519.PrivateKeySize-ed25519.PublicKeySize:]
 }
 
+// Equals compares two ed25519 private keys
 func (k *Ed25519PrivateKey) Equals(o Key) bool {
 	edk, ok := o.(*Ed25519PrivateKey)
 	if !ok {
@@ -64,10 +70,12 @@ func (k *Ed25519PrivateKey) Equals(o Key) bool {
 	return bytes.Equal(k.k, edk.k)
 }
 
+// GetPublic returns an ed25519 public key from a private key
 func (k *Ed25519PrivateKey) GetPublic() PubKey {
 	return &Ed25519PublicKey{k: k.pubKeyBytes()}
 }
 
+// Sign returns a signature from an input message
 func (k *Ed25519PrivateKey) Sign(msg []byte) ([]byte, error) {
 	return ed25519.Sign(k.k, msg), nil
 }
@@ -76,6 +84,7 @@ func (k *Ed25519PublicKey) Type() pb.KeyType {
 	return pb.KeyType_Ed25519
 }
 
+// Bytes returns a ed25519 public key as protobuf bytes
 func (k *Ed25519PublicKey) Bytes() ([]byte, error) {
 	return MarshalPublicKey(k)
 }
@@ -84,6 +93,7 @@ func (k *Ed25519PublicKey) Raw() ([]byte, error) {
 	return k.k, nil
 }
 
+// Equals compares two ed25519 public keys
 func (k *Ed25519PublicKey) Equals(o Key) bool {
 	edk, ok := o.(*Ed25519PublicKey)
 	if !ok {
@@ -93,6 +103,7 @@ func (k *Ed25519PublicKey) Equals(o Key) bool {
 	return bytes.Equal(k.k, edk.k)
 }
 
+// Verify checks a signature agains the input data
 func (k *Ed25519PublicKey) Verify(data []byte, sig []byte) (bool, error) {
 	return ed25519.Verify(k.k, data, sig), nil
 }
@@ -106,6 +117,7 @@ func UnmarshalEd25519PublicKey(data []byte) (PubKey, error) {
 	}, nil
 }
 
+// UnmarshalEd25519PrivateKey returns a private key from input bytes
 func UnmarshalEd25519PrivateKey(data []byte) (PrivKey, error) {
 	switch len(data) {
 	case ed25519.PrivateKeySize + ed25519.PublicKeySize: