Added ctx parameter to Sign and Verify interfaces to allow context pa…

…ssing in the case of remote calls to sign/verify an envelope (i.e. a KMS call)

dsse/sign.go

@@ -5,6 +5,7 @@ https://github.com/secure-systems-lab/dsse
 package dsse
 
 import (
+	"context"
 	"encoding/base64"
 	"errors"
 	"fmt"
@@ -77,7 +78,7 @@ using the current algorithm, and the key used (if applicable).
 For an example see EcdsaSigner in sign_test.go.
 */
 type Signer interface {
-	Sign(data []byte) ([]byte, error)
+	Sign(ctx context.Context, data []byte) ([]byte, error)
 	KeyID() (string, error)
 }
 
@@ -143,7 +144,7 @@ Returned is an envelope as defined here:
 https://github.com/secure-systems-lab/dsse/blob/master/envelope.md
 One signature will be added for each Signer in the EnvelopeSigner.
 */
-func (es *EnvelopeSigner) SignPayload(payloadType string, body []byte) (*Envelope, error) {
+func (es *EnvelopeSigner) SignPayload(ctx context.Context, payloadType string, body []byte) (*Envelope, error) {
 	var e = Envelope{
 		Payload:     base64.StdEncoding.EncodeToString(body),
 		PayloadType: payloadType,
@@ -152,7 +153,7 @@ func (es *EnvelopeSigner) SignPayload(payloadType string, body []byte) (*Envelop
 	paeEnc := PAE(payloadType, body)
 
 	for _, signer := range es.providers {
-		sig, err := signer.Sign(paeEnc)
+		sig, err := signer.Sign(ctx, paeEnc)
 		if err != nil {
 			return nil, err
 		}
@@ -176,8 +177,8 @@ Any domain specific validation such as parsing the decoded body and
 validating the payload type is left out to the caller.
 Verify returns a list of accepted keys each including a keyid, public and signiture of the accepted provider keys.
 */
-func (es *EnvelopeSigner) Verify(e *Envelope) ([]AcceptedKey, error) {
-	return es.ev.Verify(e)
+func (es *EnvelopeSigner) Verify(ctx context.Context, e *Envelope) ([]AcceptedKey, error) {
+	return es.ev.Verify(ctx, e)
 }
 
 /*

dsse/sign_test.go

@@ -1,6 +1,7 @@
 package dsse
 
 import (
+	"context"
 	"crypto"
 	"crypto/ecdsa"
 	"crypto/elliptic"
@@ -40,11 +41,11 @@ func TestPAE(t *testing.T) {
 
 type nilsigner int
 
-func (n nilsigner) Sign(data []byte) ([]byte, error) {
+func (n nilsigner) Sign(ctx context.Context, data []byte) ([]byte, error) {
 	return data, nil
 }
 
-func (n nilsigner) Verify(data, sig []byte) error {
+func (n nilsigner) Verify(ctx context.Context, data, sig []byte) error {
 	if len(data) != len(sig) {
 		return errLength
 	}
@@ -68,11 +69,11 @@ func (n nilsigner) Public() crypto.PublicKey {
 
 type nullsigner int
 
-func (n nullsigner) Sign(data []byte) ([]byte, error) {
+func (n nullsigner) Sign(ctx context.Context, data []byte) ([]byte, error) {
 	return data, nil
 }
 
-func (n nullsigner) Verify(data, sig []byte) error {
+func (n nullsigner) Verify(ctx context.Context, data, sig []byte) error {
 	if len(data) != len(sig) {
 		return errLength
 	}
@@ -96,11 +97,11 @@ func (n nullsigner) Public() crypto.PublicKey {
 
 type errsigner int
 
-func (n errsigner) Sign(data []byte) ([]byte, error) {
+func (n errsigner) Sign(ctx context.Context, data []byte) ([]byte, error) {
 	return nil, fmt.Errorf("signing error")
 }
 
-func (n errsigner) Verify(data, sig []byte) error {
+func (n errsigner) Verify(ctx context.Context, data, sig []byte) error {
 	return errVerify
 }
 
@@ -117,11 +118,11 @@ type errverifier int
 var errVerify = fmt.Errorf("accepted signatures do not match threshold, Found: 0, Expected 1")
 var errThreshold = fmt.Errorf("invalid threshold")
 
-func (n errverifier) Sign(data []byte) ([]byte, error) {
+func (n errverifier) Sign(ctx context.Context, data []byte) ([]byte, error) {
 	return data, nil
 }
 
-func (n errverifier) Verify(data, sig []byte) error {
+func (n errverifier) Verify(ctx context.Context, data, sig []byte) error {
 	return errVerify
 }
 
@@ -135,11 +136,11 @@ func (n errverifier) Public() crypto.PublicKey {
 
 type badverifier int
 
-func (n badverifier) Sign(data []byte) ([]byte, error) {
+func (n badverifier) Sign(ctx context.Context, data []byte) ([]byte, error) {
 	return append(data, byte(0)), nil
 }
 
-func (n badverifier) Verify(data, sig []byte) error {
+func (n badverifier) Verify(ctx context.Context, data, sig []byte) error {
 
 	if len(data) != len(sig) {
 		return errLength
@@ -199,7 +200,7 @@ func TestNilSign(t *testing.T) {
 	signer, err := NewEnvelopeSigner(ns)
 	assert.Nil(t, err, "unexpected error")
 
-	got, err := signer.SignPayload(payloadType, []byte(payload))
+	got, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 	assert.Equal(t, &want, got, "bad signature")
 }
@@ -209,7 +210,7 @@ func TestSignError(t *testing.T) {
 	signer, err := NewEnvelopeSigner(es)
 	assert.Nil(t, err, "unexpected error")
 
-	got, err := signer.SignPayload("t", []byte("d"))
+	got, err := signer.SignPayload(context.TODO(), "t", []byte("d"))
 	assert.Nil(t, got, "expected nil")
 	assert.NotNil(t, err, "error expected")
 	assert.Equal(t, "signing error", err.Error(), "wrong error")
@@ -252,7 +253,7 @@ type EcdsaSigner struct {
 	verified bool
 }
 
-func (es *EcdsaSigner) Sign(data []byte) ([]byte, error) {
+func (es *EcdsaSigner) Sign(ctx context.Context, data []byte) ([]byte, error) {
 	// Data is complete message, hash it and sign the digest
 	digest := sha256.Sum256(data)
 	r, s, err := rfc6979.SignECDSA(es.key, digest[:], sha256.New)
@@ -268,7 +269,7 @@ func (es *EcdsaSigner) Sign(data []byte) ([]byte, error) {
 	return rawSig, nil
 }
 
-func (es *EcdsaSigner) Verify(data, sig []byte) error {
+func (es *EcdsaSigner) Verify(ctx context.Context, data, sig []byte) error {
 	var r big.Int
 	var s big.Int
 	digest := sha256.Sum256(data)
@@ -319,12 +320,12 @@ func TestEcdsaSign(t *testing.T) {
 	signer, err := NewEnvelopeSigner(ecdsa)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "unexpected error")
 	assert.Equal(t, &want, env, "Wrong envelope generated")
 
 	// Now verify
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "unexpected error")
 	assert.True(t, ecdsa.verified, "verify was not called")
 	assert.Len(t, acceptedKeys, 1, "unexpected keys")
@@ -384,10 +385,10 @@ func TestVerifyOneProvider(t *testing.T) {
 	signer, err := NewEnvelopeSigner(ns)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "unexpected error")
 	assert.Len(t, acceptedKeys, 1, "unexpected keys")
 	assert.Equal(t, acceptedKeys[0].KeyID, "nil", "unexpected keyid")
@@ -402,10 +403,10 @@ func TestVerifyMultipleProvider(t *testing.T) {
 	signer, err := NewEnvelopeSigner(ns, null)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "unexpected error")
 	assert.Len(t, acceptedKeys, 2, "unexpected keys")
 }
@@ -418,10 +419,10 @@ func TestVerifyMultipleProviderThreshold(t *testing.T) {
 	var null nullsigner
 	signer, err := NewMultiEnvelopeSigner(2, ns, null)
 	assert.Nil(t, err)
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "unexpected error")
 	assert.Len(t, acceptedKeys, 2, "unexpected keys")
 }
@@ -443,10 +444,10 @@ func TestVerifyErr(t *testing.T) {
 	signer, err := NewEnvelopeSigner(errv)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	_, err = signer.Verify(env)
+	_, err = signer.Verify(context.TODO(), env)
 	assert.Equal(t, errVerify, err, "wrong error")
 }
 
@@ -458,10 +459,10 @@ func TestBadVerifier(t *testing.T) {
 	signer, err := NewEnvelopeSigner(badv)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	_, err = signer.Verify(env)
+	_, err = signer.Verify(context.TODO(), env)
 	assert.NotNil(t, err, "expected error")
 }
 
@@ -472,7 +473,7 @@ func TestVerifyNoSig(t *testing.T) {
 
 	env := &Envelope{}
 
-	_, err = signer.Verify(env)
+	_, err = signer.Verify(context.TODO(), env)
 	assert.Equal(t, ErrNoSignature, err, "wrong error")
 }
 
@@ -489,7 +490,7 @@ func TestVerifyBadBase64(t *testing.T) {
 			},
 		}
 
-		_, err := signer.Verify(env)
+		_, err := signer.Verify(context.TODO(), env)
 		assert.IsType(t, base64.CorruptInputError(0), err, "wrong error")
 	})
 
@@ -503,7 +504,7 @@ func TestVerifyBadBase64(t *testing.T) {
 			},
 		}
 
-		_, err := signer.Verify(env)
+		_, err := signer.Verify(context.TODO(), env)
 		assert.IsType(t, base64.CorruptInputError(0), err, "wrong error")
 	})
 }
@@ -527,7 +528,7 @@ func TestVerifyNoMatch(t *testing.T) {
 		},
 	}
 
-	_, err = signer.Verify(env)
+	_, err = signer.Verify(context.TODO(), env)
 	assert.NotNil(t, err, "expected error")
 }
 
@@ -537,11 +538,11 @@ type interceptSigner struct {
 	verifyCalled bool
 }
 
-func (i *interceptSigner) Sign(data []byte) ([]byte, error) {
+func (i *interceptSigner) Sign(ctx context.Context, data []byte) ([]byte, error) {
 	return data, nil
 }
 
-func (i *interceptSigner) Verify(data, sig []byte) error {
+func (i *interceptSigner) Verify(ctx context.Context, data, sig []byte) error {
 	i.verifyCalled = true
 
 	if i.verifyRes {
@@ -573,10 +574,10 @@ func TestVerifyOneFail(t *testing.T) {
 	signer, err := NewEnvelopeSigner(s1, s2)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "expected error")
 	assert.True(t, s1.verifyCalled, "verify not called")
 	assert.True(t, s2.verifyCalled, "verify not called")
@@ -599,10 +600,10 @@ func TestVerifySameKeyID(t *testing.T) {
 	signer, err := NewEnvelopeSigner(s1, s2)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "expected error")
 	assert.True(t, s1.verifyCalled, "verify not called")
 	assert.True(t, s2.verifyCalled, "verify not called")
@@ -627,10 +628,10 @@ func TestVerifyEmptyKeyID(t *testing.T) {
 	signer, err := NewEnvelopeSigner(s1, s2)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "expected error")
 	// assert.True(t, s1.verifyCalled, "verify not called")
 	// assert.True(t, s2.verifyCalled, "verify not called")
@@ -658,10 +659,10 @@ func TestVerifyPublicKeyID(t *testing.T) {
 	signer, err := NewEnvelopeSigner(s1, s2)
 	assert.Nil(t, err, "unexpected error")
 
-	env, err := signer.SignPayload(payloadType, []byte(payload))
+	env, err := signer.SignPayload(context.TODO(), payloadType, []byte(payload))
 	assert.Nil(t, err, "sign failed")
 
-	acceptedKeys, err := signer.Verify(env)
+	acceptedKeys, err := signer.Verify(context.TODO(), env)
 	assert.Nil(t, err, "expected error")
 	assert.Len(t, acceptedKeys, 1, "unexpected keys")
 	assert.Equal(t, acceptedKeys[0].KeyID, keyID, "unexpected keyid")

dsse/verify.go

@@ -1,6 +1,7 @@
 package dsse
 
 import (
+	"context"
 	"crypto"
 	"errors"
 	"fmt"
@@ -15,7 +16,7 @@ must perform the same steps.
 If KeyID returns successfully, only signature matching the key ID will be verified.
 */
 type Verifier interface {
-	Verify(data, sig []byte) error
+	Verify(ctx context.Context, data, sig []byte) error
 	KeyID() (string, error)
 	Public() crypto.PublicKey
 }
@@ -31,7 +32,7 @@ type AcceptedKey struct {
 	Sig    Signature
 }
 
-func (ev *EnvelopeVerifier) Verify(e *Envelope) ([]AcceptedKey, error) {
+func (ev *EnvelopeVerifier) Verify(ctx context.Context, e *Envelope) ([]AcceptedKey, error) {
 	if e == nil {
 		return nil, errors.New("cannot verify a nil envelope")
 	}
@@ -78,7 +79,7 @@ func (ev *EnvelopeVerifier) Verify(e *Envelope) ([]AcceptedKey, error) {
 				continue
 			}
 
-			err = v.Verify(paeEnc, sig)
+			err = v.Verify(ctx, paeEnc, sig)
 			if err != nil {
 				continue
 			}