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|
package hpke
import (
"bytes"
"crypto/rand"
"fmt"
"testing"
"github.com/cloudflare/circl/internal/test"
)
func TestAeadExporter(t *testing.T) {
suite := Suite{kdfID: KDF_HKDF_SHA256, aeadID: AEAD_AES128GCM}
exporter := &encdecContext{suite: suite}
maxLength := uint(255 * suite.kdfID.ExtractSize())
err := test.CheckPanic(func() {
exporter.Export([]byte("exporter"), maxLength+1)
})
test.CheckNoErr(t, err, "exporter max size")
}
func setupAeadTest() (*sealContext, *openContext, error) {
suite := Suite{aeadID: AEAD_AES128GCM}
key := make([]byte, suite.aeadID.KeySize())
if n, err := rand.Read(key); err != nil {
return nil, nil, err
} else if n != len(key) {
return nil, nil, fmt.Errorf("unexpected key size: got %d; want %d", n, len(key))
}
aead, err := suite.aeadID.New(key)
if err != nil {
return nil, nil, err
}
Nn := suite.aeadID.NonceSize()
baseNonce := make([]byte, Nn)
if n, err := rand.Read(baseNonce); err != nil {
return nil, nil, err
} else if n != len(baseNonce) {
return nil, nil, fmt.Errorf("unexpected base nonce size: got %d; want %d", n, len(baseNonce))
}
sealer := &sealContext{
&encdecContext{
suite, nil, nil, nil, nil, nil, baseNonce, make([]byte, Nn), aead, make([]byte, Nn),
},
}
opener := &openContext{
&encdecContext{
suite, nil, nil, nil, nil, nil, baseNonce, make([]byte, Nn), aead, make([]byte, Nn),
},
}
return sealer, opener, nil
}
func TestAeadNonceUpdate(t *testing.T) {
sealer, opener, err := setupAeadTest()
test.CheckNoErr(t, err, "setup failed")
pt := []byte("plaintext")
aad := []byte("aad")
numAttempts := 2
var prevCt []byte
for i := 0; i < numAttempts; i++ {
ct, err := sealer.Seal(pt, aad)
if err != nil {
t.Fatalf("encryption failed: %s", err)
}
if prevCt != nil && bytes.Equal(ct, prevCt) {
t.Error("ciphertext matches the previous (nonce not updated)")
}
_, err = opener.Open(ct, aad)
if err != nil {
t.Errorf("decryption failed: %s", err)
}
prevCt = ct
}
}
func TestOpenPhaseMismatch(t *testing.T) {
sealer, opener, err := setupAeadTest()
test.CheckNoErr(t, err, "setup failed")
pt := []byte("plaintext")
aad := []byte("aad")
ct, err := sealer.Seal(pt, aad)
if err != nil {
t.Fatalf("encryption failed: %s", err)
}
recovered, err := opener.Open(ct, aad)
if err != nil {
t.Fatalf("decryption failed: %s", err)
}
if !bytes.Equal(pt, recovered) {
t.Fatal("Plaintext mismatch")
}
_, err = opener.Open(ct, aad)
if err == nil {
t.Fatal("decryption succeeded when it should have failed")
}
}
func TestSealPhaseMismatch(t *testing.T) {
sealer, opener, err := setupAeadTest()
test.CheckNoErr(t, err, "setup failed")
pt := []byte("plaintext")
aad := []byte("aad")
_, err = sealer.Seal(pt, aad)
if err != nil {
t.Fatalf("encryption failed: %s", err)
}
ct, err := sealer.Seal(pt, aad)
if err != nil {
t.Fatalf("encryption failed: %s", err)
}
_, err = opener.Open(ct, aad)
if err == nil {
t.Fatal("decryption succeeded when it should have failed")
}
}
func TestAeadSeqOverflow(t *testing.T) {
sealer, opener, err := setupAeadTest()
test.CheckNoErr(t, err, "setup failed")
Nn := len(sealer.baseNonce)
pt := []byte("plaintext")
aad := []byte("aad")
// Sets sequence number to 256 before its max value = 0xFF...FF.
for i := 0; i < Nn; i++ {
sealer.sequenceNumber[i] = 0xFF
opener.sequenceNumber[i] = 0xFF
}
sealer.sequenceNumber[Nn-1] = 0x00
opener.sequenceNumber[Nn-1] = 0x00
numAttempts := 260
wantCorrect := 2 * 255
wantIncorrect := 2*numAttempts - wantCorrect
gotCorrect := 0
gotIncorrect := 0
for i := 0; i < numAttempts; i++ {
ct, err := sealer.Seal(pt, aad)
switch {
case ct != nil && err == nil:
gotCorrect++
case ct == nil && err != nil:
gotIncorrect++
default:
t.FailNow()
}
pt2, err := opener.Open(ct, aad)
switch {
case pt2 != nil && err == nil:
gotCorrect++
case pt2 == nil && err != nil:
gotIncorrect++
default:
t.FailNow()
}
}
if gotCorrect != wantCorrect {
test.ReportError(t, gotCorrect, wantCorrect)
}
if gotIncorrect != wantIncorrect {
test.ReportError(t, gotIncorrect, wantIncorrect)
}
}
|
