| // Copyright 2020 Google LLC |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| //////////////////////////////////////////////////////////////////////////////// |
| |
| package prf_test |
| |
| import ( |
| "bytes" |
| "encoding/hex" |
| "fmt" |
| "testing" |
| |
| "github.com/google/go-cmp/cmp" |
| "google.golang.org/protobuf/proto" |
| "github.com/google/tink/go/core/registry" |
| "github.com/google/tink/go/internal/internalregistry" |
| "github.com/google/tink/go/prf" |
| "github.com/google/tink/go/prf/subtle" |
| "github.com/google/tink/go/subtle/random" |
| "github.com/google/tink/go/testutil" |
| commonpb "github.com/google/tink/go/proto/common_go_proto" |
| hmacpb "github.com/google/tink/go/proto/hmac_prf_go_proto" |
| tinkpb "github.com/google/tink/go/proto/tink_go_proto" |
| ) |
| |
| func TestGetPrimitiveHMACBasic(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("HMAC PRF key manager not found: %s", err) |
| } |
| testKeys := genValidHMACPRFKeys() |
| for i := 0; i < len(testKeys); i++ { |
| serializedKey, _ := proto.Marshal(testKeys[i]) |
| p, err := km.Primitive(serializedKey) |
| if err != nil { |
| t.Errorf("unexpected error in test case %d: %s", i, err) |
| } |
| if err := validateHMACPRFPrimitive(p, testKeys[i]); err != nil { |
| t.Errorf("%s", err) |
| } |
| } |
| } |
| |
| func TestGetPrimitiveHMACWithInvalidInput(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("cannot obtain HMAC PRFkey manager: %s", err) |
| } |
| // invalid key |
| testKeys := genInvalidHMACPRFKeys() |
| for i := 0; i < len(testKeys); i++ { |
| serializedKey, _ := proto.Marshal(testKeys[i]) |
| if _, err := km.Primitive(serializedKey); err == nil { |
| t.Errorf("expect an error in test case %d", i) |
| } |
| } |
| if _, err := km.Primitive(nil); err == nil { |
| t.Errorf("expect an error when input is nil") |
| } |
| // empty input |
| if _, err := km.Primitive([]byte{}); err == nil { |
| t.Errorf("expect an error when input is empty") |
| } |
| } |
| |
| func TestNewKeyHMACMultipleTimes(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("cannot obtain HMAC PRF key manager: %s", err) |
| } |
| serializedFormat, _ := proto.Marshal(testutil.NewHMACPRFKeyFormat(commonpb.HashType_SHA256)) |
| keys := make(map[string]bool) |
| nTest := 26 |
| for i := 0; i < nTest; i++ { |
| key, _ := km.NewKey(serializedFormat) |
| serializedKey, _ := proto.Marshal(key) |
| keys[string(serializedKey)] = true |
| |
| keyData, _ := km.NewKeyData(serializedFormat) |
| serializedKey = keyData.Value |
| keys[string(serializedKey)] = true |
| } |
| if len(keys) != nTest*2 { |
| t.Errorf("key is repeated") |
| } |
| } |
| |
| func TestNewKeyHMACBasic(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("cannot obtain HMAC PRF key manager: %s", err) |
| } |
| testFormats := genValidHMACPRFKeyFormats() |
| for i := 0; i < len(testFormats); i++ { |
| serializedFormat, _ := proto.Marshal(testFormats[i]) |
| key, err := km.NewKey(serializedFormat) |
| if err != nil { |
| t.Errorf("unexpected error in test case %d: %s", i, err) |
| } |
| if err := validateHMACPRFKey(testFormats[i], key.(*hmacpb.HmacPrfKey)); err != nil { |
| t.Errorf("%s", err) |
| } |
| } |
| } |
| |
| func TestNewKeyHMACWithInvalidInput(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("cannot obtain HMAC PRF key manager: %s", err) |
| } |
| // invalid key formats |
| testFormats := genInvalidHMACPRFKeyFormats() |
| for i := 0; i < len(testFormats); i++ { |
| serializedFormat, err := proto.Marshal(testFormats[i]) |
| if err != nil { |
| fmt.Println("Error!") |
| } |
| if _, err := km.NewKey(serializedFormat); err == nil { |
| t.Errorf("expect an error in test case %d: %s", i, err) |
| } |
| } |
| if _, err := km.NewKey(nil); err == nil { |
| t.Errorf("expect an error when input is nil") |
| } |
| // empty input |
| if _, err := km.NewKey([]byte{}); err == nil { |
| t.Errorf("expect an error when input is empty") |
| } |
| } |
| |
| func TestNewKeyDataHMACBasic(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("cannot obtain HMAC PRF key manager: %s", err) |
| } |
| testFormats := genValidHMACPRFKeyFormats() |
| for i := 0; i < len(testFormats); i++ { |
| serializedFormat, _ := proto.Marshal(testFormats[i]) |
| keyData, err := km.NewKeyData(serializedFormat) |
| if err != nil { |
| t.Errorf("unexpected error in test case %d: %s", i, err) |
| } |
| if keyData.TypeUrl != testutil.HMACPRFTypeURL { |
| t.Errorf("incorrect type url in test case %d", i) |
| } |
| if keyData.KeyMaterialType != tinkpb.KeyData_SYMMETRIC { |
| t.Errorf("incorrect key material type in test case %d", i) |
| } |
| key := new(hmacpb.HmacPrfKey) |
| if err := proto.Unmarshal(keyData.Value, key); err != nil { |
| t.Errorf("invalid key value") |
| } |
| if err := validateHMACPRFKey(testFormats[i], key); err != nil { |
| t.Errorf("invalid key") |
| } |
| } |
| } |
| |
| func TestNewKeyDataHMACWithInvalidInput(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("HMAC PRF key manager not found: %s", err) |
| } |
| // invalid key formats |
| testFormats := genInvalidHMACPRFKeyFormats() |
| for i := 0; i < len(testFormats); i++ { |
| serializedFormat, _ := proto.Marshal(testFormats[i]) |
| if _, err := km.NewKeyData(serializedFormat); err == nil { |
| t.Errorf("expect an error in test case %d", i) |
| } |
| } |
| // nil input |
| if _, err := km.NewKeyData(nil); err == nil { |
| t.Errorf("expect an error when input is nil") |
| } |
| } |
| |
| func TestHMACDoesSupport(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("HMAC PRF key manager not found: %s", err) |
| } |
| if !km.DoesSupport(testutil.HMACPRFTypeURL) { |
| t.Errorf("HMACPRFKeyManager must support %s", testutil.HMACPRFTypeURL) |
| } |
| if km.DoesSupport("some bad type") { |
| t.Errorf("HMACPRFKeyManager must support only %s", testutil.HMACPRFTypeURL) |
| } |
| } |
| |
| func TestHMACTypeURL(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Errorf("HMAC PRF key manager not found: %s", err) |
| } |
| if km.TypeURL() != testutil.HMACPRFTypeURL { |
| t.Errorf("incorrect GetKeyType()") |
| } |
| } |
| |
| func TestHMACKeyMaterialType(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Fatalf("registry.GetKeyManager(%q) err = %v, want nil", testutil.HMACPRFTypeURL, err) |
| } |
| keyManager, ok := km.(internalregistry.DerivableKeyManager) |
| if !ok { |
| t.Fatalf("key manager is not DerivableKeyManager") |
| } |
| if got, want := keyManager.KeyMaterialType(), tinkpb.KeyData_SYMMETRIC; got != want { |
| t.Errorf("KeyMaterialType() = %v, want %v", got, want) |
| } |
| } |
| |
| func TestHMACDeriveKey(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Fatalf("registry.GetKeyManager(%q) err = %v, want nil", testutil.HMACPRFTypeURL, err) |
| } |
| keyManager, ok := km.(internalregistry.DerivableKeyManager) |
| if !ok { |
| t.Fatalf("key manager is not DerivableKeyManager") |
| } |
| keyFormat, err := proto.Marshal(&hmacpb.HmacPrfKeyFormat{ |
| Version: testutil.HMACPRFKeyVersion, |
| KeySize: 16, |
| Params: &hmacpb.HmacPrfParams{Hash: commonpb.HashType_SHA256}, |
| }) |
| if err != nil { |
| t.Fatalf("proto.Marshal() err = %v, want nil", err) |
| } |
| rand := random.GetRandomBytes(16) |
| buf := &bytes.Buffer{} |
| buf.Write(rand) // Never returns a non-nil error. |
| k, err := keyManager.DeriveKey(keyFormat, buf) |
| if err != nil { |
| t.Fatalf("keyManager.DeriveKey() err = %v, want nil", err) |
| } |
| key := k.(*hmacpb.HmacPrfKey) |
| if got, want := len(key.GetKeyValue()), 16; got != want { |
| t.Errorf("key length = %d, want %d", got, want) |
| } |
| if diff := cmp.Diff(key.GetKeyValue(), rand); diff != "" { |
| t.Errorf("incorrect derived key: diff = %v", diff) |
| } |
| } |
| |
| func TestHMACDeriveKeyFailsWithInvalidKeyFormats(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Fatalf("registry.GetKeyManager(%q) err = %v, want nil", testutil.HMACPRFTypeURL, err) |
| } |
| keyManager, ok := km.(internalregistry.DerivableKeyManager) |
| if !ok { |
| t.Fatalf("key manager is not DerivableKeyManager") |
| } |
| |
| validKeyFormat := &hmacpb.HmacPrfKeyFormat{ |
| Version: testutil.HMACPRFKeyVersion, |
| KeySize: 16, |
| Params: &hmacpb.HmacPrfParams{Hash: commonpb.HashType_SHA256}, |
| } |
| serializedValidKeyFormat, err := proto.Marshal(validKeyFormat) |
| if err != nil { |
| t.Fatalf("proto.Marshal(%v) err = %v, want nil", validKeyFormat, err) |
| } |
| buf := bytes.NewBuffer(random.GetRandomBytes(validKeyFormat.KeySize)) |
| if _, err := keyManager.DeriveKey(serializedValidKeyFormat, buf); err != nil { |
| t.Fatalf("keyManager.DeriveKey() err = %v, want nil", err) |
| } |
| |
| for _, test := range []struct { |
| name string |
| version uint32 |
| keySize uint32 |
| hash commonpb.HashType |
| }{ |
| { |
| name: "invalid version", |
| version: 10, |
| keySize: validKeyFormat.KeySize, |
| hash: validKeyFormat.Params.Hash, |
| }, |
| { |
| name: "invalid key size", |
| version: validKeyFormat.Version, |
| keySize: 10, |
| hash: validKeyFormat.Params.Hash, |
| }, |
| { |
| name: "invalid hash", |
| version: validKeyFormat.Version, |
| keySize: validKeyFormat.KeySize, |
| hash: commonpb.HashType_UNKNOWN_HASH, |
| }, |
| } { |
| t.Run(test.name, func(t *testing.T) { |
| keyFormat, err := proto.Marshal(&hmacpb.HmacPrfKeyFormat{ |
| Version: test.version, |
| KeySize: test.keySize, |
| Params: &hmacpb.HmacPrfParams{Hash: test.hash}, |
| }) |
| if err != nil { |
| t.Fatalf("proto.Marshal() err = %v, want nil", err) |
| } |
| buf := bytes.NewBuffer(random.GetRandomBytes(test.keySize)) |
| if _, err := keyManager.DeriveKey(keyFormat, buf); err == nil { |
| t.Errorf("keyManager.DeriveKey() err = nil, want non-nil") |
| } |
| }) |
| } |
| } |
| |
| func TestHMACDeriveKeyFailsWithMalformedKeyFormats(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Fatalf("registry.GetKeyManager(%q) err = %v, want nil", testutil.HMACPRFTypeURL, err) |
| } |
| keyManager, ok := km.(internalregistry.DerivableKeyManager) |
| if !ok { |
| t.Fatalf("key manager is not DerivableKeyManager") |
| } |
| // Proto messages start with a VarInt, which always ends with a byte with the |
| // MSB unset, so 0x80 is invalid. |
| invalidSerialization, err := hex.DecodeString("80") |
| if err != nil { |
| t.Errorf("hex.DecodeString() err = %v, want nil", err) |
| } |
| for _, test := range []struct { |
| name string |
| keyFormat []byte |
| }{ |
| { |
| name: "nil", |
| keyFormat: nil, |
| }, |
| { |
| name: "empty", |
| keyFormat: []byte{}, |
| }, |
| { |
| name: "invalid serialization", |
| keyFormat: invalidSerialization, |
| }, |
| } { |
| t.Run(test.name, func(t *testing.T) { |
| buf := bytes.NewBuffer(random.GetRandomBytes(16)) |
| if _, err := keyManager.DeriveKey(test.keyFormat, buf); err == nil { |
| t.Errorf("keyManager.DeriveKey() err = nil, want non-nil") |
| } |
| }) |
| } |
| } |
| |
| func TestHMACDeriveKeyFailsWithInsufficientRandomness(t *testing.T) { |
| km, err := registry.GetKeyManager(testutil.HMACPRFTypeURL) |
| if err != nil { |
| t.Fatalf("registry.GetKeyManager(%q) err = %v, want nil", testutil.HMACPRFTypeURL, err) |
| } |
| keyManager, ok := km.(internalregistry.DerivableKeyManager) |
| if !ok { |
| t.Fatalf("key manager is not DerivableKeyManager") |
| } |
| keyFormat, err := proto.Marshal(&hmacpb.HmacPrfKeyFormat{ |
| Version: testutil.HMACPRFKeyVersion, |
| KeySize: 16, |
| Params: &hmacpb.HmacPrfParams{Hash: commonpb.HashType_SHA256}, |
| }) |
| if err != nil { |
| t.Fatalf("proto.Marshal(%v) err = %v, want nil", keyFormat, err) |
| } |
| { |
| buf := bytes.NewBuffer(random.GetRandomBytes(16)) |
| if _, err := keyManager.DeriveKey(keyFormat, buf); err != nil { |
| t.Errorf("keyManager.DeriveKey() err = %v, want nil", err) |
| } |
| } |
| { |
| insufficientBuf := bytes.NewBuffer(random.GetRandomBytes(15)) |
| if _, err := keyManager.DeriveKey(keyFormat, insufficientBuf); err == nil { |
| t.Errorf("keyManager.DeriveKey() err = nil, want non-nil") |
| } |
| } |
| } |
| |
| func genInvalidHMACPRFKeys() []proto.Message { |
| badVersionKey := testutil.NewHMACPRFKey(commonpb.HashType_SHA256) |
| badVersionKey.Version++ |
| shortKey := testutil.NewHMACPRFKey(commonpb.HashType_SHA256) |
| shortKey.KeyValue = []byte{1, 1} |
| return []proto.Message{ |
| // not a HMACPRFKey |
| testutil.NewHMACParams(commonpb.HashType_SHA256, 32), |
| // bad version |
| badVersionKey, |
| // key too short |
| shortKey, |
| // unknown hash type |
| testutil.NewHMACPRFKey(commonpb.HashType_UNKNOWN_HASH), |
| } |
| } |
| |
| func genInvalidHMACPRFKeyFormats() []proto.Message { |
| shortKeyFormat := testutil.NewHMACPRFKeyFormat(commonpb.HashType_SHA256) |
| shortKeyFormat.KeySize = 1 |
| return []proto.Message{ |
| // not a HMACPRFKeyFormat |
| testutil.NewHMACParams(commonpb.HashType_SHA256, 32), |
| // key too short |
| shortKeyFormat, |
| // unknown hash type |
| testutil.NewHMACPRFKeyFormat(commonpb.HashType_UNKNOWN_HASH), |
| } |
| } |
| |
| func genValidHMACPRFKeyFormats() []*hmacpb.HmacPrfKeyFormat { |
| return []*hmacpb.HmacPrfKeyFormat{ |
| testutil.NewHMACPRFKeyFormat(commonpb.HashType_SHA1), |
| testutil.NewHMACPRFKeyFormat(commonpb.HashType_SHA256), |
| testutil.NewHMACPRFKeyFormat(commonpb.HashType_SHA512), |
| } |
| } |
| |
| func genValidHMACPRFKeys() []*hmacpb.HmacPrfKey { |
| return []*hmacpb.HmacPrfKey{ |
| testutil.NewHMACPRFKey(commonpb.HashType_SHA1), |
| testutil.NewHMACPRFKey(commonpb.HashType_SHA256), |
| testutil.NewHMACPRFKey(commonpb.HashType_SHA512), |
| } |
| } |
| |
| // Checks whether the given HMACPRFKey matches the given key HMACPRFKeyFormat |
| func validateHMACPRFKey(format *hmacpb.HmacPrfKeyFormat, key *hmacpb.HmacPrfKey) error { |
| if format.KeySize != uint32(len(key.KeyValue)) || |
| key.Params.Hash != format.Params.Hash { |
| return fmt.Errorf("key format and generated key do not match") |
| } |
| p, err := subtle.NewHMACPRF(commonpb.HashType_name[int32(key.Params.Hash)], key.KeyValue) |
| if err != nil { |
| return fmt.Errorf("cannot create primitive from key: %s", err) |
| } |
| return validateHMACPRFPrimitive(p, key) |
| } |
| |
| // validateHMACPRFPrimitive checks whether the given primitive can compute a PRF of length 16 |
| func validateHMACPRFPrimitive(p interface{}, key *hmacpb.HmacPrfKey) error { |
| hmac := p.(prf.PRF) |
| prfPrimitive, err := subtle.NewHMACPRF(commonpb.HashType_name[int32(key.Params.Hash)], key.KeyValue) |
| if err != nil { |
| return fmt.Errorf("Could not create HMAC PRF with key material %q: %s", hex.EncodeToString(key.KeyValue), err) |
| } |
| data := random.GetRandomBytes(20) |
| res, err := hmac.ComputePRF(data, 16) |
| if err != nil { |
| return fmt.Errorf("prf computation failed: %s", err) |
| } |
| if len(res) != 16 { |
| return fmt.Errorf("prf computation did not produce 16 byte output") |
| } |
| res2, err := prfPrimitive.ComputePRF(data, 16) |
| if err != nil { |
| return fmt.Errorf("prf computation failed: %s", err) |
| } |
| if len(res2) != 16 { |
| return fmt.Errorf("prf computation did not produce 16 byte output") |
| } |
| if hex.EncodeToString(res) != hex.EncodeToString(res2) { |
| return fmt.Errorf("prf computation did not produce the same output for the same key and input") |
| } |
| return nil |
| } |
