| // Copyright 2022 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" |
| "math/rand" |
| "testing" |
| |
| "github.com/google/tink/go/subtle/random" |
| "github.com/google/tink/go/subtle" |
| pb "github.com/google/tink/go/proto/hpke_go_proto" |
| ) |
| |
| func TestNewEncryptDecryptUnknownKEM(t *testing.T) { |
| params := validParams(t) |
| params.Kem = pb.HpkeKem_KEM_UNKNOWN |
| pubKey, privKey := pubPrivKeys(t, params) |
| |
| if _, err := NewEncrypt(pubKey); err == nil { |
| t.Error("NewEncrypt(unknown KEM): got success, want err") |
| } |
| if _, err := NewDecrypt(privKey); err == nil { |
| t.Error("NewDecrypt(unknown KEM): got success, want err") |
| } |
| } |
| |
| func TestNewEncryptDecryptUnknownKDF(t *testing.T) { |
| params := validParams(t) |
| params.Kdf = pb.HpkeKdf_KDF_UNKNOWN |
| pubKey, privKey := pubPrivKeys(t, params) |
| |
| if _, err := NewEncrypt(pubKey); err == nil { |
| t.Error("NewEncrypt(unknown KDF): got success, want err") |
| } |
| if _, err := NewDecrypt(privKey); err == nil { |
| t.Error("NewDecrypt(unknown KDF): got success, want err") |
| } |
| } |
| |
| func TestNewEncryptDecryptUnknownAEAD(t *testing.T) { |
| params := validParams(t) |
| params.Aead = pb.HpkeAead_AEAD_UNKNOWN |
| pubKey, privKey := pubPrivKeys(t, params) |
| |
| if _, err := NewEncrypt(pubKey); err == nil { |
| t.Error("NewEncrypt(unknown AEAD): got success, want err") |
| } |
| if _, err := NewDecrypt(privKey); err == nil { |
| t.Error("NewDecrypt(unknown AEAD): got success, want err") |
| } |
| } |
| |
| func TestNewEncryptDecryptMissingParams(t *testing.T) { |
| pubKey, privKey := pubPrivKeys(t, nil) |
| |
| if _, err := NewEncrypt(pubKey); err == nil { |
| t.Error("NewEncrypt(missing params): got success, want err") |
| } |
| if _, err := NewDecrypt(privKey); err == nil { |
| t.Error("NewDecrypt(missing params): got success, want err") |
| } |
| } |
| |
| func TestNewEncryptMissingPubKeyBytes(t *testing.T) { |
| pubKey, _ := pubPrivKeys(t, validParams(t)) |
| pubKey.PublicKey = nil |
| if _, err := NewEncrypt(pubKey); err == nil { |
| t.Error("NewEncrypt(nil pub key): got success, want err") |
| } |
| pubKey.PublicKey = []byte{} |
| if _, err := NewEncrypt(pubKey); err == nil { |
| t.Error("NewEncrypt(zero-length pub key): got success, want err") |
| } |
| } |
| |
| func TestNewDecryptMissingPrivKeyBytes(t *testing.T) { |
| _, privKey := pubPrivKeys(t, validParams(t)) |
| privKey.PrivateKey = nil |
| if _, err := NewDecrypt(privKey); err == nil { |
| t.Error("NewDecrypt(nil priv key): got success, want err") |
| } |
| privKey.PrivateKey = []byte{} |
| if _, err := NewDecrypt(privKey); err == nil { |
| t.Error("NewDecrypt(zero-length priv key): got success, want err") |
| } |
| } |
| |
| func TestEncryptDecrypt(t *testing.T) { |
| aeadIDs := []pb.HpkeAead{pb.HpkeAead_AES_128_GCM, pb.HpkeAead_AES_256_GCM, pb.HpkeAead_CHACHA20_POLY1305} |
| for _, aeadID := range aeadIDs { |
| params := &pb.HpkeParams{ |
| Kem: pb.HpkeKem_DHKEM_X25519_HKDF_SHA256, |
| Kdf: pb.HpkeKdf_HKDF_SHA256, |
| Aead: aeadID, |
| } |
| pubKey, privKey := pubPrivKeys(t, params) |
| |
| enc, err := NewEncrypt(pubKey) |
| if err != nil { |
| t.Fatalf("NewEncrypt: err %q", err) |
| } |
| dec, err := NewDecrypt(privKey) |
| if err != nil { |
| t.Fatalf("NewDecrypt: err %q", err) |
| } |
| |
| wantPT := random.GetRandomBytes(200) |
| ctxInfo := random.GetRandomBytes(100) |
| ct, err := enc.Encrypt(wantPT, ctxInfo) |
| if err != nil { |
| t.Fatalf("Encrypt: err %q", err) |
| } |
| gotPT, err := dec.Decrypt(ct, ctxInfo) |
| if err != nil { |
| t.Fatalf("Decrypt: err %q", err) |
| } |
| if !bytes.Equal(gotPT, wantPT) { |
| t.Errorf("Decrypt: got %q, want %q", gotPT, wantPT) |
| } |
| } |
| } |
| |
| func TestDecryptModifiedCiphertextOrContextInfo(t *testing.T) { |
| pubKey, privKey := pubPrivKeys(t, validParams(t)) |
| enc, err := NewEncrypt(pubKey) |
| if err != nil { |
| t.Fatalf("NewEncrypt: err %q", err) |
| } |
| dec, err := NewDecrypt(privKey) |
| if err != nil { |
| t.Fatalf("NewDecrypt: err %q", err) |
| } |
| |
| wantPT := random.GetRandomBytes(200) |
| ctxInfo := random.GetRandomBytes(100) |
| ct, err := enc.Encrypt(wantPT, ctxInfo) |
| if err != nil { |
| t.Fatalf("Encrypt: err %q", err) |
| } |
| gotPT, err := dec.Decrypt(ct, ctxInfo) |
| if err != nil { |
| t.Fatalf("Decrypt: err %q", err) |
| } |
| if !bytes.Equal(gotPT, wantPT) { |
| t.Errorf("Decrypt: got %q, want %q", gotPT, wantPT) |
| } |
| |
| tests := []struct { |
| name string |
| ct []byte |
| ctxInfo []byte |
| }{ |
| {"extended ct", append(ct, []byte("hi there")...), ctxInfo}, |
| {"flip byte ct", flipRandByte(t, ct), ctxInfo}, |
| {"short ct", ct[:len(ct)-5], ctxInfo}, |
| {"empty ct", []byte{}, ctxInfo}, |
| {"extended ctxInfo", ct, append(ctxInfo, []byte("hi there")...)}, |
| {"flip byte ctxInfo", ct, flipRandByte(t, ctxInfo)}, |
| {"short ctxInfo", ct, ctxInfo[:len(ctxInfo)-5]}, |
| {"empty ctxInfo", ct, []byte{}}, |
| } |
| |
| for _, test := range tests { |
| t.Run(test.name, func(t *testing.T) { |
| if _, err := dec.Decrypt(test.ct, test.ctxInfo); err == nil { |
| t.Error("Decrypt: got success, want err") |
| } |
| }) |
| } |
| } |
| |
| func TestEncryptDecryptEmptyContextInfo(t *testing.T) { |
| pubKey, privKey := pubPrivKeys(t, validParams(t)) |
| enc, err := NewEncrypt(pubKey) |
| if err != nil { |
| t.Fatalf("NewEncrypt: err %q", err) |
| } |
| dec, err := NewDecrypt(privKey) |
| if err != nil { |
| t.Fatalf("NewDecrypt: err %q", err) |
| } |
| |
| wantPT := random.GetRandomBytes(200) |
| ctxInfo := []byte{} |
| ct, err := enc.Encrypt(wantPT, ctxInfo) |
| if err != nil { |
| t.Fatalf("Encrypt: err %q", err) |
| } |
| gotPT, err := dec.Decrypt(ct, ctxInfo) |
| if err != nil { |
| t.Fatalf("Decrypt: err %q", err) |
| } |
| if !bytes.Equal(gotPT, wantPT) { |
| t.Errorf("Decrypt: got %q, want %q", gotPT, wantPT) |
| } |
| } |
| |
| // TestDecryptEncapsulatedKeyWithFlippedMSB checks that ciphertexts with its |
| // encapsulated key MSB flipped fails to decrypt. See details at b/213886185. |
| func TestDecryptEncapsulatedKeyWithFlippedMSB(t *testing.T) { |
| pubKey, privKey := pubPrivKeys(t, validParams(t)) |
| enc, err := NewEncrypt(pubKey) |
| if err != nil { |
| t.Fatalf("NewEncrypt: err %q", err) |
| } |
| dec, err := NewDecrypt(privKey) |
| if err != nil { |
| t.Fatalf("NewDecrypt: err %q", err) |
| } |
| |
| wantPT := random.GetRandomBytes(200) |
| ctxInfo := random.GetRandomBytes(100) |
| ct, err := enc.Encrypt(wantPT, ctxInfo) |
| if err != nil { |
| t.Fatalf("Encrypt: err %q", err) |
| } |
| gotPT, err := dec.Decrypt(ct, ctxInfo) |
| if err != nil { |
| t.Fatalf("Decrypt: err %q", err) |
| } |
| if !bytes.Equal(gotPT, wantPT) { |
| t.Errorf("Decrypt: got %q, want %q", gotPT, wantPT) |
| } |
| |
| // Flip the MSB of the encapsulated key, which is the first 32 bytes of ct. |
| ct[31] = ct[31] ^ 128 |
| if _, err := dec.Decrypt(ct, ctxInfo); err == nil { |
| t.Error("Decrypt with encapsulated key MSB flipped: got success, want err") |
| } |
| } |
| |
| func validParams(t *testing.T) *pb.HpkeParams { |
| t.Helper() |
| return &pb.HpkeParams{ |
| Kem: pb.HpkeKem_DHKEM_X25519_HKDF_SHA256, |
| Kdf: pb.HpkeKdf_HKDF_SHA256, |
| Aead: pb.HpkeAead_AES_256_GCM, |
| } |
| } |
| |
| func pubPrivKeys(t *testing.T, params *pb.HpkeParams) (*pb.HpkePublicKey, *pb.HpkePrivateKey) { |
| t.Helper() |
| |
| priv, err := subtle.GeneratePrivateKeyX25519() |
| if err != nil { |
| t.Fatalf("GeneratePrivateKeyX25519: err %q", err) |
| } |
| pub, err := subtle.PublicFromPrivateX25519(priv) |
| if err != nil { |
| t.Fatalf("PublicFromPrivateX25519: err %q", err) |
| } |
| |
| pubKey := &pb.HpkePublicKey{ |
| Version: 0, |
| Params: params, |
| PublicKey: pub, |
| } |
| privKey := &pb.HpkePrivateKey{ |
| Version: 0, |
| PublicKey: pubKey, |
| PrivateKey: priv, |
| } |
| return pubKey, privKey |
| } |
| |
| func flipRandByte(t *testing.T, b []byte) []byte { |
| t.Helper() |
| ret := make([]byte, len(b)) |
| copy(ret, b) |
| randByte := rand.Intn(len(b)) |
| ret[randByte] = ret[randByte] ^ 255 |
| return ret |
| } |