test partial read

common/crypto/auth_test.go

@@ -63,6 +63,62 @@ func TestAuthenticationReaderWriter(t *testing.T) {
 	assert.Error(err).Equals(io.EOF)
 }
 
+func TestAuthenticationReaderWriterPartial(t *testing.T) {
+	assert := assert.On(t)
+
+	key := make([]byte, 16)
+	rand.Read(key)
+	block, err := aes.NewCipher(key)
+	assert.Error(err).IsNil()
+
+	aead, err := cipher.NewGCM(block)
+	assert.Error(err).IsNil()
+
+	payload := make([]byte, 8*1024)
+	rand.Read(payload)
+
+	cache := buf.NewLocal(16 * 1024)
+	iv := make([]byte, 12)
+	rand.Read(iv)
+
+	writer := NewAuthenticationWriter(&AEADAuthenticator{
+		AEAD: aead,
+		NonceGenerator: &StaticBytesGenerator{
+			Content: iv,
+		},
+		AdditionalDataGenerator: &NoOpBytesGenerator{},
+	}, cache)
+
+	nBytes, err := writer.Write(payload)
+	assert.Error(err).IsNil()
+	assert.Int(nBytes).Equals(len(payload))
+	assert.Int(cache.Len()).GreaterThan(0)
+	_, err = writer.Write([]byte{})
+	assert.Error(err).IsNil()
+
+	reader := NewAuthenticationReader(&AEADAuthenticator{
+		AEAD: aead,
+		NonceGenerator: &StaticBytesGenerator{
+			Content: iv,
+		},
+		AdditionalDataGenerator: &NoOpBytesGenerator{},
+	}, cache, false)
+
+	actualPayload := make([]byte, 7*1024)
+	nBytes, err = reader.Read(actualPayload)
+	assert.Error(err).IsNil()
+	assert.Int(nBytes).Equals(len(actualPayload))
+	assert.Bytes(actualPayload[:nBytes]).Equals(payload[:nBytes])
+
+	nBytes, err = reader.Read(actualPayload)
+	assert.Error(err).IsNil()
+	assert.Int(nBytes).Equals(len(payload) - len(actualPayload))
+	assert.Bytes(actualPayload[:nBytes]).Equals(payload[7*1024:])
+
+	_, err = reader.Read(actualPayload)
+	assert.Error(err).Equals(io.EOF)
+}
+
 func TestAuthenticationReaderWriterAggressive(t *testing.T) {
 	assert := assert.On(t)