siv_aead: Overhead is always 16

Add a test for that.

Also test operations using a 64-byte key.
This commit is contained in:
Jakob Unterwurzacher 2016-10-03 23:58:19 +02:00
parent b7be386e46
commit 46018785b4
2 changed files with 84 additions and 6 deletions

View File

@ -8,7 +8,31 @@ import (
"github.com/jacobsa/crypto/siv"
)
func TestAll(t *testing.T) {
// Test all supported key lengths
func TestKeyLens(t *testing.T) {
keyLens := []int{32, 48, 64}
nonce := make([]byte, 16)
plaintext := []byte("foobar")
for _, keyLen := range keyLens {
key := make([]byte, keyLen)
a := New(key)
ciphertext2 := a.Seal(nil, nonce, plaintext, nil)
ciphertext, err := siv.Encrypt(nil, key, plaintext, [][]byte{nil, nonce})
if err != nil {
t.Error(err)
} else if o := len(ciphertext) - len(plaintext); o != a.Overhead() {
t.Errorf("keyLen=%d, actual overhead: %d\n", keyLen, o)
}
if !bytes.Equal(ciphertext, ciphertext2) {
t.Errorf("siv and siv_aead produce different results")
}
}
}
// Test using a 32-byte key
func TestK32(t *testing.T) {
key := bytes.Repeat([]byte{1}, 32)
nonce := bytes.Repeat([]byte{2}, 16)
plaintext := []byte{1, 2, 3, 4, 5, 6, 7, 8, 9}
@ -64,3 +88,61 @@ func TestAll(t *testing.T) {
t.Error("should have failed")
}
}
// Test using a 64-byte key
func TestK64(t *testing.T) {
key := bytes.Repeat([]byte{1}, 64)
nonce := bytes.Repeat([]byte{2}, 16)
plaintext := []byte{1, 2, 3, 4, 5, 6, 7, 8, 9}
aData := make([]byte, 24)
// Compare siv and siv_aead results
sResult, err := siv.Encrypt(nonce, key, plaintext, [][]byte{aData, nonce})
if err != nil {
t.Fatal(err)
}
a := New(key)
aResult := a.Seal(nonce, nonce, plaintext, aData)
if !bytes.Equal(sResult, aResult) {
t.Errorf("siv and siv_aead produce different results")
}
expectedResult, _ := hex.DecodeString(
"02020202020202020202020202020202317b316f67c3ad336c01c9a01b4c5e552ba89e966bc4c1ade1")
if !bytes.Equal(aResult, expectedResult) {
t.Errorf(hex.EncodeToString(aResult))
}
// Verify overhead
overhead := len(aResult) - len(plaintext) - len(nonce)
if overhead != a.Overhead() {
t.Errorf("Overhead() returns a wrong value")
}
// Decrypt
p1, err := a.Open(nil, aResult[:16], aResult[16:], aData)
if err != nil {
t.Error(err)
}
if !bytes.Equal(plaintext, p1) {
t.Errorf("wrong plaintext")
}
// Decrypt and append
dst := []byte{0xaa, 0xbb, 0xcc}
p2, err := a.Open(dst, aResult[:16], aResult[16:], aData)
if err != nil {
t.Error(err)
}
p2e := append(dst, plaintext...)
if !bytes.Equal(p2e, p2) {
t.Errorf("wrong plaintext: %s", hex.EncodeToString(p2))
}
// Decrypt corrupt
aResult[17] = 0
_, err = a.Open(nil, aResult[:16], aResult[16:], aData)
if err == nil {
t.Error("should have failed")
}
// Decrypt and append corrupt
aResult[17] = 0
_, err = a.Open(dst, aResult[:16], aResult[16:], aData)
if err == nil {
t.Error("should have failed")
}
}

View File

@ -22,11 +22,7 @@ func (s *sivAead) NonceSize() int {
}
func (s *sivAead) Overhead() int {
// RFC5297:
// [...] the key length used by AES in CTR and S2V is len(K)/2 and will
// each be either 128 bits, 192 bits, or 256 bits.
return len(s.key) / 2
return 16
}
// Seal - encrypt "in" using "nonce" and "authData" and append the result to "dst"