1 files changed, 428 insertions, 0 deletions
diff --git a/vendor/github.com/docker/libtrust/ec_key.go b/vendor/github.com/docker/libtrust/ec_key.go
new file mode 100644
index 000000000..00bbe4b3c
--- /dev/null
+++ b/vendor/github.com/docker/libtrust/ec_key.go
@@ -0,0 +1,428 @@
+package libtrust
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/x509"
+	"encoding/json"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"io"
+	"math/big"
+)
+
+/*
+ * EC DSA PUBLIC KEY
+ */
+
+// ecPublicKey implements a libtrust.PublicKey using elliptic curve digital
+// signature algorithms.
+type ecPublicKey struct {
+	*ecdsa.PublicKey
+	curveName          string
+	signatureAlgorithm *signatureAlgorithm
+	extended           map[string]interface{}
+}
+
+func fromECPublicKey(cryptoPublicKey *ecdsa.PublicKey) (*ecPublicKey, error) {
+	curve := cryptoPublicKey.Curve
+
+	switch {
+	case curve == elliptic.P256():
+		return &ecPublicKey{cryptoPublicKey, "P-256", es256, map[string]interface{}{}}, nil
+	case curve == elliptic.P384():
+		return &ecPublicKey{cryptoPublicKey, "P-384", es384, map[string]interface{}{}}, nil
+	case curve == elliptic.P521():
+		return &ecPublicKey{cryptoPublicKey, "P-521", es512, map[string]interface{}{}}, nil
+	default:
+		return nil, errors.New("unsupported elliptic curve")
+	}
+}
+
+// KeyType returns the key type for elliptic curve keys, i.e., "EC".
+func (k *ecPublicKey) KeyType() string {
+	return "EC"
+}
+
+// CurveName returns the elliptic curve identifier.
+// Possible values are "P-256", "P-384", and "P-521".
+func (k *ecPublicKey) CurveName() string {
+	return k.curveName
+}
+
+// KeyID returns a distinct identifier which is unique to this Public Key.
+func (k *ecPublicKey) KeyID() string {
+	return keyIDFromCryptoKey(k)
+}
+
+func (k *ecPublicKey) String() string {
+	return fmt.Sprintf("EC Public Key <%s>", k.KeyID())
+}
+
+// Verify verifyies the signature of the data in the io.Reader using this
+// PublicKey. The alg parameter should identify the digital signature
+// algorithm which was used to produce the signature and should be supported
+// by this public key. Returns a nil error if the signature is valid.
+func (k *ecPublicKey) Verify(data io.Reader, alg string, signature []byte) error {
+	// For EC keys there is only one supported signature algorithm depending
+	// on the curve parameters.
+	if k.signatureAlgorithm.HeaderParam() != alg {
+		return fmt.Errorf("unable to verify signature: EC Public Key with curve %q does not support signature algorithm %q", k.curveName, alg)
+	}
+
+	// signature is the concatenation of (r, s), base64Url encoded.
+	sigLength := len(signature)
+	expectedOctetLength := 2 * ((k.Params().BitSize + 7) >> 3)
+	if sigLength != expectedOctetLength {
+		return fmt.Errorf("signature length is %d octets long, should be %d", sigLength, expectedOctetLength)
+	}
+
+	rBytes, sBytes := signature[:sigLength/2], signature[sigLength/2:]
+	r := new(big.Int).SetBytes(rBytes)
+	s := new(big.Int).SetBytes(sBytes)
+
+	hasher := k.signatureAlgorithm.HashID().New()
+	_, err := io.Copy(hasher, data)
+	if err != nil {
+		return fmt.Errorf("error reading data to sign: %s", err)
+	}
+	hash := hasher.Sum(nil)
+
+	if !ecdsa.Verify(k.PublicKey, hash, r, s) {
+		return errors.New("invalid signature")
+	}
+
+	return nil
+}
+
+// CryptoPublicKey returns the internal object which can be used as a
+// crypto.PublicKey for use with other standard library operations. The type
+// is either *rsa.PublicKey or *ecdsa.PublicKey
+func (k *ecPublicKey) CryptoPublicKey() crypto.PublicKey {
+	return k.PublicKey
+}
+
+func (k *ecPublicKey) toMap() map[string]interface{} {
+	jwk := make(map[string]interface{})
+	for k, v := range k.extended {
+		jwk[k] = v
+	}
+	jwk["kty"] = k.KeyType()
+	jwk["kid"] = k.KeyID()
+	jwk["crv"] = k.CurveName()
+
+	xBytes := k.X.Bytes()
+	yBytes := k.Y.Bytes()
+	octetLength := (k.Params().BitSize + 7) >> 3
+	// MUST include leading zeros in the output so that x, y are each
+	// *octetLength* bytes long.
+	xBuf := make([]byte, octetLength-len(xBytes), octetLength)
+	yBuf := make([]byte, octetLength-len(yBytes), octetLength)
+	xBuf = append(xBuf, xBytes...)
+	yBuf = append(yBuf, yBytes...)
+
+	jwk["x"] = joseBase64UrlEncode(xBuf)
+	jwk["y"] = joseBase64UrlEncode(yBuf)
+
+	return jwk
+}
+
+// MarshalJSON serializes this Public Key using the JWK JSON serialization format for
+// elliptic curve keys.
+func (k *ecPublicKey) MarshalJSON() (data []byte, err error) {
+	return json.Marshal(k.toMap())
+}
+
+// PEMBlock serializes this Public Key to DER-encoded PKIX format.
+func (k *ecPublicKey) PEMBlock() (*pem.Block, error) {
+	derBytes, err := x509.MarshalPKIXPublicKey(k.PublicKey)
+	if err != nil {
+		return nil, fmt.Errorf("unable to serialize EC PublicKey to DER-encoded PKIX format: %s", err)
+	}
+	k.extended["kid"] = k.KeyID() // For display purposes.
+	return createPemBlock("PUBLIC KEY", derBytes, k.extended)
+}
+
+func (k *ecPublicKey) AddExtendedField(field string, value interface{}) {
+	k.extended[field] = value
+}
+
+func (k *ecPublicKey) GetExtendedField(field string) interface{} {
+	v, ok := k.extended[field]
+	if !ok {
+		return nil
+	}
+	return v
+}
+
+func ecPublicKeyFromMap(jwk map[string]interface{}) (*ecPublicKey, error) {
+	// JWK key type (kty) has already been determined to be "EC".
+	// Need to extract 'crv', 'x', 'y', and 'kid' and check for
+	// consistency.
+
+	// Get the curve identifier value.
+	crv, err := stringFromMap(jwk, "crv")
+	if err != nil {
+		return nil, fmt.Errorf("JWK EC Public Key curve identifier: %s", err)
+	}
+
+	var (
+		curve  elliptic.Curve
+		sigAlg *signatureAlgorithm
+	)
+
+	switch {
+	case crv == "P-256":
+		curve = elliptic.P256()
+		sigAlg = es256
+	case crv == "P-384":
+		curve = elliptic.P384()
+		sigAlg = es384
+	case crv == "P-521":
+		curve = elliptic.P521()
+		sigAlg = es512
+	default:
+		return nil, fmt.Errorf("JWK EC Public Key curve identifier not supported: %q\n", crv)
+	}
+
+	// Get the X and Y coordinates for the public key point.
+	xB64Url, err := stringFromMap(jwk, "x")
+	if err != nil {
+		return nil, fmt.Errorf("JWK EC Public Key x-coordinate: %s", err)
+	}
+	x, err := parseECCoordinate(xB64Url, curve)
+	if err != nil {
+		return nil, fmt.Errorf("JWK EC Public Key x-coordinate: %s", err)
+	}
+
+	yB64Url, err := stringFromMap(jwk, "y")
+	if err != nil {
+		return nil, fmt.Errorf("JWK EC Public Key y-coordinate: %s", err)
+	}
+	y, err := parseECCoordinate(yB64Url, curve)
+	if err != nil {
+		return nil, fmt.Errorf("JWK EC Public Key y-coordinate: %s", err)
+	}
+
+	key := &ecPublicKey{
+		PublicKey: &ecdsa.PublicKey{Curve: curve, X: x, Y: y},
+		curveName: crv, signatureAlgorithm: sigAlg,
+	}
+
+	// Key ID is optional too, but if it exists, it should match the key.
+	_, ok := jwk["kid"]
+	if ok {
+		kid, err := stringFromMap(jwk, "kid")
+		if err != nil {
+			return nil, fmt.Errorf("JWK EC Public Key ID: %s", err)
+		}
+		if kid != key.KeyID() {
+			return nil, fmt.Errorf("JWK EC Public Key ID does not match: %s", kid)
+		}
+	}
+
+	key.extended = jwk
+
+	return key, nil
+}
+
+/*
+ * EC DSA PRIVATE KEY
+ */
+
+// ecPrivateKey implements a JWK Private Key using elliptic curve digital signature
+// algorithms.
+type ecPrivateKey struct {
+	ecPublicKey
+	*ecdsa.PrivateKey
+}
+
+func fromECPrivateKey(cryptoPrivateKey *ecdsa.PrivateKey) (*ecPrivateKey, error) {
+	publicKey, err := fromECPublicKey(&cryptoPrivateKey.PublicKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return &ecPrivateKey{*publicKey, cryptoPrivateKey}, nil
+}
+
+// PublicKey returns the Public Key data associated with this Private Key.
+func (k *ecPrivateKey) PublicKey() PublicKey {
+	return &k.ecPublicKey
+}
+
+func (k *ecPrivateKey) String() string {
+	return fmt.Sprintf("EC Private Key <%s>", k.KeyID())
+}
+
+// Sign signs the data read from the io.Reader using a signature algorithm supported
+// by the elliptic curve private key. If the specified hashing algorithm is
+// supported by this key, that hash function is used to generate the signature
+// otherwise the the default hashing algorithm for this key is used. Returns
+// the signature and the name of the JWK signature algorithm used, e.g.,
+// "ES256", "ES384", "ES512".
+func (k *ecPrivateKey) Sign(data io.Reader, hashID crypto.Hash) (signature []byte, alg string, err error) {
+	// Generate a signature of the data using the internal alg.
+	// The given hashId is only a suggestion, and since EC keys only support
+	// on signature/hash algorithm given the curve name, we disregard it for
+	// the elliptic curve JWK signature implementation.
+	hasher := k.signatureAlgorithm.HashID().New()
+	_, err = io.Copy(hasher, data)
+	if err != nil {
+		return nil, "", fmt.Errorf("error reading data to sign: %s", err)
+	}
+	hash := hasher.Sum(nil)
+
+	r, s, err := ecdsa.Sign(rand.Reader, k.PrivateKey, hash)
+	if err != nil {
+		return nil, "", fmt.Errorf("error producing signature: %s", err)
+	}
+	rBytes, sBytes := r.Bytes(), s.Bytes()
+	octetLength := (k.ecPublicKey.Params().BitSize + 7) >> 3
+	// MUST include leading zeros in the output
+	rBuf := make([]byte, octetLength-len(rBytes), octetLength)
+	sBuf := make([]byte, octetLength-len(sBytes), octetLength)
+
+	rBuf = append(rBuf, rBytes...)
+	sBuf = append(sBuf, sBytes...)
+
+	signature = append(rBuf, sBuf...)
+	alg = k.signatureAlgorithm.HeaderParam()
+
+	return
+}
+
+// CryptoPrivateKey returns the internal object which can be used as a
+// crypto.PublicKey for use with other standard library operations. The type
+// is either *rsa.PublicKey or *ecdsa.PublicKey
+func (k *ecPrivateKey) CryptoPrivateKey() crypto.PrivateKey {
+	return k.PrivateKey
+}
+
+func (k *ecPrivateKey) toMap() map[string]interface{} {
+	jwk := k.ecPublicKey.toMap()
+
+	dBytes := k.D.Bytes()
+	// The length of this octet string MUST be ceiling(log-base-2(n)/8)
+	// octets (where n is the order of the curve). This is because the private
+	// key d must be in the interval [1, n-1] so the bitlength of d should be
+	// no larger than the bitlength of n-1. The easiest way to find the octet
+	// length is to take bitlength(n-1), add 7 to force a carry, and shift this
+	// bit sequence right by 3, which is essentially dividing by 8 and adding
+	// 1 if there is any remainder. Thus, the private key value d should be
+	// output to (bitlength(n-1)+7)>>3 octets.
+	n := k.ecPublicKey.Params().N
+	octetLength := (new(big.Int).Sub(n, big.NewInt(1)).BitLen() + 7) >> 3
+	// Create a buffer with the necessary zero-padding.
+	dBuf := make([]byte, octetLength-len(dBytes), octetLength)
+	dBuf = append(dBuf, dBytes...)
+
+	jwk["d"] = joseBase64UrlEncode(dBuf)
+
+	return jwk
+}
+
+// MarshalJSON serializes this Private Key using the JWK JSON serialization format for
+// elliptic curve keys.
+func (k *ecPrivateKey) MarshalJSON() (data []byte, err error) {
+	return json.Marshal(k.toMap())
+}
+
+// PEMBlock serializes this Private Key to DER-encoded PKIX format.
+func (k *ecPrivateKey) PEMBlock() (*pem.Block, error) {
+	derBytes, err := x509.MarshalECPrivateKey(k.PrivateKey)
+	if err != nil {
+		return nil, fmt.Errorf("unable to serialize EC PrivateKey to DER-encoded PKIX format: %s", err)
+	}
+	k.extended["keyID"] = k.KeyID() // For display purposes.
+	return createPemBlock("EC PRIVATE KEY", derBytes, k.extended)
+}
+
+func ecPrivateKeyFromMap(jwk map[string]interface{}) (*ecPrivateKey, error) {
+	dB64Url, err := stringFromMap(jwk, "d")
+	if err != nil {
+		return nil, fmt.Errorf("JWK EC Private Key: %s", err)
+	}
+
+	// JWK key type (kty) has already been determined to be "EC".
+	// Need to extract the public key information, then extract the private
+	// key value 'd'.
+	publicKey, err := ecPublicKeyFromMap(jwk)
+	if err != nil {
+		return nil, err
+	}
+
+	d, err := parseECPrivateParam(dB64Url, publicKey.Curve)
+	if err != nil {
+		return nil, fmt.Errorf("JWK EC Private Key d-param: %s", err)
+	}
+
+	key := &ecPrivateKey{
+		ecPublicKey: *publicKey,
+		PrivateKey: &ecdsa.PrivateKey{
+			PublicKey: *publicKey.PublicKey,
+			D:         d,
+		},
+	}
+
+	return key, nil
+}
+
+/*
+ *	Key Generation Functions.
+ */
+
+func generateECPrivateKey(curve elliptic.Curve) (k *ecPrivateKey, err error) {
+	k = new(ecPrivateKey)
+	k.PrivateKey, err = ecdsa.GenerateKey(curve, rand.Reader)
+	if err != nil {
+		return nil, err
+	}
+
+	k.ecPublicKey.PublicKey = &k.PrivateKey.PublicKey
+	k.extended = make(map[string]interface{})
+
+	return
+}
+
+// GenerateECP256PrivateKey generates a key pair using elliptic curve P-256.
+func GenerateECP256PrivateKey() (PrivateKey, error) {
+	k, err := generateECPrivateKey(elliptic.P256())
+	if err != nil {
+		return nil, fmt.Errorf("error generating EC P-256 key: %s", err)
+	}
+
+	k.curveName = "P-256"
+	k.signatureAlgorithm = es256
+
+	return k, nil
+}
+
+// GenerateECP384PrivateKey generates a key pair using elliptic curve P-384.
+func GenerateECP384PrivateKey() (PrivateKey, error) {
+	k, err := generateECPrivateKey(elliptic.P384())
+	if err != nil {
+		return nil, fmt.Errorf("error generating EC P-384 key: %s", err)
+	}
+
+	k.curveName = "P-384"
+	k.signatureAlgorithm = es384
+
+	return k, nil
+}
+
+// GenerateECP521PrivateKey generates aß key pair using elliptic curve P-521.
+func GenerateECP521PrivateKey() (PrivateKey, error) {
+	k, err := generateECPrivateKey(elliptic.P521())
+	if err != nil {
+		return nil, fmt.Errorf("error generating EC P-521 key: %s", err)
+	}
+
+	k.curveName = "P-521"
+	k.signatureAlgorithm = es512
+
+	return k, nil
+}