Resolve several TODO's (#103)

Remove RequestMatcher TODO
Resolve cassette.Decrypt TODO
Resolve Response TODO: Close, Uncompressed
Resolve nonceGen validation TODO

cassette/cassette.go

@@ -332,7 +332,6 @@ func getEncryptionMarker(data []byte) string {
 
 // Decrypt is a utility function that decrypts the cassette raw data
 // with the use of the supplied crypter.
-// TODO: move this method to the encryption package??
 func Decrypt(data []byte, crypter Crypter) ([]byte, error) {
 	encMarker := getEncryptionMarker(data)
 	markerLen := len(encMarker)

cassette/track/http.go

@@ -184,6 +184,8 @@ type Response struct {
 	Body             []byte
 	ContentLength    int64
 	TransferEncoding []string
+	Close            bool
+	Uncompressed     bool
 	Trailer          http.Header
 	TLS              *tls.ConnectionState
 
@@ -219,6 +221,8 @@ func ToResponse(httpResponse *http.Response) *Response {
 		Body:             bodyClone,
 		ContentLength:    httpResponse.ContentLength,
 		TransferEncoding: tsfEncodingClone,
+		Close:            httpResponse.Close,
+		Uncompressed:     httpResponse.Uncompressed,
 		Trailer:          trailerClone,
 		TLS:              tlsClone,
 	}

cassette/track/track.go

@@ -137,7 +137,8 @@ func (trk Track) ToHTTPResponse() *http.Response {
 	httpResponse.Body = bodyReadCloser
 	httpResponse.ContentLength = trk.Response.ContentLength
 	httpResponse.TransferEncoding = trk.Response.TransferEncoding
-	// TODO: Close, Uncompressed ?
+	httpResponse.Close = trk.Response.Close
+	httpResponse.Uncompressed = trk.Response.Uncompressed
 	httpResponse.Trailer = trk.Response.Trailer
 	httpResponse.TLS = trk.Response.TLS
 

cassette/track/track_test.go

@@ -77,6 +77,8 @@ func TestTrack_ToHTTPResponse(t *testing.T) {
 			Body:             []byte("resp body"),
 			ContentLength:    826,
 			TransferEncoding: []string{"resp tsf_encoding"},
+			Close:            true,
+			Uncompressed:     true,
 			Trailer: map[string][]string{
 				"resptr1": {"resptrva11", "resptrva22"},
 			},
@@ -104,8 +106,8 @@ func TestTrack_ToHTTPResponse(t *testing.T) {
 		Body:             nil, // we assert Body separately because it's an io.Reader
 		ContentLength:    826,
 		TransferEncoding: []string{"resp tsf_encoding"},
-		Close:            false,
-		Uncompressed:     false,
+		Close:            true,
+		Uncompressed:     true,
 		Trailer: map[string][]string{
 			"resptr1": {"resptrva11", "resptrva22"},
 		},

encryption/aesgcm.go

@@ -4,6 +4,8 @@ import (
 	"crypto/aes"
 	"crypto/cipher"
 
+	"github.com/pkg/errors"
+
 	cryptoerr "github.com/seborama/govcr/v12/encryption/errors"
 )
 
@@ -21,8 +23,6 @@ func NewAESGCMWithRandomNonceGenerator(key []byte) (*Crypter, error) {
 //
 // If you want to convert a passphrase to a key, use a suitable
 // package like bcrypt or scrypt.
-//
-// TODO: add a nonceGenerator validator i.e. call it 1000 times, ensures no dupes.
 func NewAESGCM(key []byte, nonceGenerator NonceGenerator) (*Crypter, error) {
 	if len(key) != 16 && len(key) != 32 {
 		return nil, cryptoerr.NewErrCrypto("key size is not 16 or 32 bytes")
@@ -42,5 +42,9 @@ func NewAESGCM(key []byte, nonceGenerator NonceGenerator) (*Crypter, error) {
 		nonceGenerator = NewRandomNonceGenerator(aesgcm.NonceSize())
 	}
 
+	if err = validateNonceGenerator(nonceGenerator); err != nil {
+		return nil, errors.Wrap(err, "nonce generator is not valid")
+	}
+
 	return NewCrypter(aesgcm, "aesgcm", nonceGenerator), nil
 }

encryption/chacha20poly1305.go

@@ -1,6 +1,7 @@
 package encryption
 
 import (
+	"github.com/pkg/errors"
 	"golang.org/x/crypto/chacha20poly1305"
 )
 
@@ -17,8 +18,6 @@ func NewChaCha20Poly1305WithRandomNonceGenerator(key []byte) (*Crypter, error) {
 // The key should be 32 bytes long.
 //
 // If you want to convert a passphrase to a key, you can use a function such as Argon2.
-//
-// TODO: add a nonceGenerator validator i.e. call it 1000 times, ensures no dupes.
 func NewChaCha20Poly1305(key []byte, nonceGenerator NonceGenerator) (*Crypter, error) {
 	cc20px, err := chacha20poly1305.NewX(key)
 	if err != nil {
@@ -29,5 +28,9 @@ func NewChaCha20Poly1305(key []byte, nonceGenerator NonceGenerator) (*Crypter, e
 		nonceGenerator = NewRandomNonceGenerator(cc20px.NonceSize())
 	}
 
+	if err = validateNonceGenerator(nonceGenerator); err != nil {
+		return nil, errors.Wrap(err, "nonce generator is not valid")
+	}
+
 	return NewCrypter(cc20px, "chacha20poly1305", nonceGenerator), nil
 }

encryption/nonce.go

@@ -2,7 +2,10 @@ package encryption
 
 import (
 	"crypto/rand"
+	"fmt"
 	"io"
+
+	"github.com/pkg/errors"
 )
 
 // RandomNonceGenerator is a random generator of nonce of the specified size.
@@ -28,3 +31,23 @@ func (ng RandomNonceGenerator) Generate() ([]byte, error) {
 
 	return nonce, nil
 }
+
+func validateNonceGenerator(nonceGenerator NonceGenerator) error {
+	nonces := make(map[string]struct{})
+
+	for i := 1; i <= 1000; i++ {
+		n, err := nonceGenerator.Generate()
+		if err != nil {
+			return errors.Wrap(err, "nonceGenerator failure")
+		}
+
+		nStr := fmt.Sprintf("%x", n)
+		if _, ok := nonces[nStr]; ok {
+			return errors.New("nonceGenerator produces frequent duplicates")
+		}
+
+		nonces[nStr] = struct{}{}
+	}
+
+	return nil
+}

encryption/nonce_wb_test.go

@@ -0,0 +1,37 @@
+package encryption
+
+import (
+	"testing"
+
+	"github.com/pkg/errors"
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_validateNonceGenerator_Passes(t *testing.T) {
+	err := validateNonceGenerator(NewRandomNonceGenerator(32))
+	assert.NoError(t, err)
+}
+
+func Test_validateNonceGenerator_Fails_NonceGenErr(t *testing.T) {
+	err := validateNonceGenerator(brokenNonceGenerator{})
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "nonceGenerator failure: broken nonce")
+}
+
+func Test_validateNonceGenerator_Fails_WeakNonceGen(t *testing.T) {
+	err := validateNonceGenerator(weakNonceGenerator{})
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "nonceGenerator produces frequent duplicates")
+}
+
+type brokenNonceGenerator struct{}
+
+func (ng brokenNonceGenerator) Generate() ([]byte, error) {
+	return nil, errors.New("broken nonce")
+}
+
+type weakNonceGenerator struct{}
+
+func (ng weakNonceGenerator) Generate() ([]byte, error) {
+	return []byte("static nonce"), nil
+}

pcb.go

@@ -155,10 +155,6 @@ func (pcb *PrintedCircuitBoard) ClearReplayingMutators() {
 
 // RequestMatcher is an interface that exposes the method to perform request comparison.
 // request comparison involves the HTTP request and the track request recorded on cassette.
-//
-// TODO:
-// there could be a case to have RequestMatchers (plural) that would work akin to track.Mutators.
-// I.e. they could be chained and conditional.
 type RequestMatcher interface {
 	Match(httpRequest, trackRequest *track.Request) bool
 }