| // Copyright 2021 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 hpke |
| |
| import ( |
| "bytes" |
| "errors" |
| "fmt" |
| "testing" |
| |
| "github.com/google/tink/go/subtle" |
| ) |
| |
| // TODO(b/201070904): Write tests using internetDraftVector. |
| func TestX25519KEMEncapsulateBoringSSLVectors(t *testing.T) { |
| i := 0 |
| vecs := baseModeX25519HKDFSHA256Vectors(t) |
| for key, vec := range vecs { |
| if key.mode != baseMode || |
| key.kemID != x25519HKDFSHA256 || |
| key.kdfID != hkdfSHA256 || |
| (key.aeadID != aes128GCM && key.aeadID != aes256GCM && key.aeadID != chaCha20Poly1305) { |
| continue |
| } |
| |
| i++ |
| t.Run(fmt.Sprintf("%d", key.id), func(t *testing.T) { |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| x25519KEMGeneratePrivateKey = func() ([]byte, error) { |
| return vec.senderPrivKey, nil |
| } |
| |
| secret, enc, err := kem.encapsulate(vec.recipientPubKey) |
| if err != nil { |
| t.Errorf("encapsulate for vector %v: got err %q, want success", key, err) |
| } |
| if !bytes.Equal(secret, vec.sharedSecret) { |
| t.Errorf("encapsulate for vector %v: got shared secret %v, want %v", key, secret, vec.sharedSecret) |
| } |
| if !bytes.Equal(enc, vec.encapsulatedKey) { |
| t.Errorf("encapsulate for vector %v: got encapsulated key %v, want %v", key, enc, vec.encapsulatedKey) |
| } |
| }) |
| } |
| x25519KEMGeneratePrivateKey = subtle.GeneratePrivateKeyX25519 |
| if i < 2 { |
| t.Errorf("number of vectors tested = %d, want > %d", i, 2) |
| } |
| } |
| |
| func TestX25519KEMEncapsulateBadRecipientPubKey(t *testing.T) { |
| _, v := internetDraftVector(t) |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| badRecipientPubKey := append(v.recipientPubKey, []byte("hello")...) |
| if _, _, err := kem.encapsulate(badRecipientPubKey); err == nil { |
| t.Error("encapsulate: got success, want err") |
| } |
| } |
| |
| func TestX25519KEMEncapsulateBadSenderPrivKey(t *testing.T) { |
| _, v := internetDraftVector(t) |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| |
| x25519KEMPublicFromPrivate = func(privKey []byte) ([]byte, error) { |
| return nil, errors.New("failed to compute public key") |
| } |
| if _, _, err := kem.encapsulate(v.recipientPubKey); err == nil { |
| t.Error("encapsulate: got success, want err") |
| } |
| x25519KEMPublicFromPrivate = subtle.PublicFromPrivateX25519 |
| } |
| |
| func TestX25519KEMDecapsulateBoringSSLVectors(t *testing.T) { |
| i := 0 |
| vecs := baseModeX25519HKDFSHA256Vectors(t) |
| for key, vec := range vecs { |
| if key.mode != baseMode || |
| key.kemID != x25519HKDFSHA256 || |
| key.kdfID != hkdfSHA256 || |
| (key.aeadID != aes128GCM && key.aeadID != aes256GCM && key.aeadID != chaCha20Poly1305) { |
| continue |
| } |
| |
| i++ |
| t.Run(fmt.Sprintf("%d", key.id), func(t *testing.T) { |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| secret, err := kem.decapsulate(vec.encapsulatedKey, vec.recipientPrivKey) |
| if err != nil { |
| t.Errorf("decapsulate for vector %v: got err %q, want success", key, err) |
| } |
| if !bytes.Equal(secret, vec.sharedSecret) { |
| t.Errorf("decapsulate for vector %v: got shared secret %v, want %v", key, secret, vec.sharedSecret) |
| } |
| }) |
| } |
| if i < 2 { |
| t.Errorf("number of vectors tested = %d, want > %d", i, 2) |
| } |
| } |
| |
| // TestX25519KEMDecapsulateEncapsulatedKeyPrefixesLargerSlice checks--if the |
| // encapsulated key is part of a larger slice, as in HPKE Encrypt |
| // https://github.com/google/tink/blob/619b6c1bb1f8573ca56de50cfc6ba23d355670db/go/hybrid/hpke/encrypt.go#L61 |
| // --that decapsulate does not modify the larger slice. |
| func TestX25519KEMDecapsulateEncapsulatedKeyPrefixesLargerSlice(t *testing.T) { |
| _, v := internetDraftVector(t) |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| |
| largerSlice := make([]byte, 3*len(v.encapsulatedKey)) |
| suffix := largerSlice[len(v.encapsulatedKey):] |
| zeroedSlice := make([]byte, len(suffix)) |
| if !bytes.Equal(suffix, zeroedSlice) { |
| t.Errorf("suffix: got %x, want %x", suffix, zeroedSlice) |
| } |
| |
| copy(largerSlice, v.encapsulatedKey) |
| if !bytes.Equal(suffix, zeroedSlice) { |
| t.Errorf("suffix: got %x, want %x", suffix, zeroedSlice) |
| } |
| |
| encapsulatedKey := largerSlice[:len(v.encapsulatedKey)] |
| if _, err := kem.decapsulate(encapsulatedKey, v.recipientPrivKey); err != nil { |
| t.Errorf("decapsulate: got err %q, want success", err) |
| } |
| if !bytes.Equal(suffix, zeroedSlice) { |
| t.Errorf("suffix: got %x, want %x", suffix, zeroedSlice) |
| } |
| } |
| |
| func TestX25519KEMDecapsulateBadEncapsulatedKey(t *testing.T) { |
| _, v := internetDraftVector(t) |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| badEncapsulatedKey := append(v.encapsulatedKey, []byte("hello")...) |
| if _, err := kem.decapsulate(badEncapsulatedKey, v.recipientPrivKey); err == nil { |
| t.Error("decapsulate: got success, want err") |
| } |
| } |
| |
| func TestX25519KEMDecapsulateBadRecipientPrivKey(t *testing.T) { |
| _, v := internetDraftVector(t) |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| badRecipientPrivKey := append(v.recipientPrivKey, []byte("hello")...) |
| if _, err := kem.decapsulate(v.encapsulatedKey, badRecipientPrivKey); err == nil { |
| t.Error("decapsulate: got success, want err") |
| } |
| } |
| |
| func TestX25519KEMEncapsulatedKeyLength(t *testing.T) { |
| kem, err := newKEM(x25519HKDFSHA256) |
| if err != nil { |
| t.Fatal(err) |
| } |
| if kem.encapsulatedKeyLength() != 32 { |
| t.Errorf("encapsulatedKeyLength: got %d, want 32", kem.encapsulatedKeyLength()) |
| } |
| } |