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add support for AES-128-GCM and ChaCha20Poly1305 with 128 bit keys #58

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Merged
aead merged 1 commit into from
Apr 29, 2026
Merged

add support for AES-128-GCM and ChaCha20Poly1305 with 128 bit keys #58

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10 changes: 5 additions & 5 deletions cmd/ncrypt/main.go
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Original file line number Diff line number Diff line change
Expand Up @@ -152,7 +152,7 @@ func cipherSuites() []byte {
case "":
return []byte{} // use platform specific cipher
case "AES256":
return []byte{sio.AES_256_GCM}
return []byte{sio.AES_GCM}
case "C20P1305":
return []byte{sio.CHACHA20_POLY1305}
}
Expand Down Expand Up @@ -196,21 +196,21 @@ func parseIOArgs() (*os.File, *os.File) {
}

func readPassword(src *os.File) []byte {
state, err := term.GetState(int(src.Fd()))
state, err := term.GetState(int(src.Fd())) // #nosec G115
if err != nil {
fmt.Fprintln(os.Stderr, "Failed to read password:", err)
exit(codeError)
}
cleanFn = append(cleanFn, func(code int) {
stat, _ := term.GetState(int(src.Fd()))
stat, _ := term.GetState(int(src.Fd())) // #nosec G115
if code == codeCancel && stat != nil && *stat != *state {
_, _ = fmt.Fprintln(src, "\nFailed to read password: Interrupted")
}
_ = term.Restore(int(src.Fd()), state)
_ = term.Restore(int(src.Fd()), state) // #nosec G115
})

_, _ = fmt.Fprint(src, "Enter password:")
password, err := term.ReadPassword(int(src.Fd()))
password, err := term.ReadPassword(int(src.Fd())) // #nosec G115
if err != nil {
fmt.Fprintln(os.Stderr, "Failed to read password:", err)
exit(codeError)
Expand Down
44 changes: 41 additions & 3 deletions dare_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,44 @@ func isZero(p []byte) bool {
return true
}

func TestSealOpen(t *testing.T) {
key128, _ := hex.DecodeString("000102030405060708090a0b0c0d0e0f")
key256, _ := hex.DecodeString("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f")
randValue, _ := hex.DecodeString("0001020304050607")

for _, maxVersion := range []byte{Version10, Version20} {
for _, key := range [][]byte{key128, key256} {
config := Config{
MinVersion: Version10,
MaxVersion: maxVersion,
CipherSuites: []byte{AES_GCM, CHACHA20_POLY1305},
Key: key,
Rand: bytes.NewReader(randValue),
PayloadSize: maxPayloadSize,
}
plaintext := make([]byte, maxPayloadSize-1)
ciphertext := make([]byte, maxPayloadSize-1+32)

enc, err := newAuthEncV10(&config)
if err != nil {
t.Errorf("Failed to create authenticated encryption scheme: %v", err)
}
enc.Seal(ciphertext, plaintext)

dec, err := newAuthDecV10(&config)
if err != nil {
t.Errorf("Failed to create authenticated decryption scheme: %v", err)
}
if err = dec.Open(plaintext, ciphertext); err != nil {
t.Errorf("Failed to open ciphertext: %v", err)
}
if !isZero(plaintext) {
t.Errorf("Decryption failed")
}
}
}
}

func TestSealV10(t *testing.T) {
key, _ := hex.DecodeString("000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f")
randValue, _ := hex.DecodeString("0001020304050607")
Expand Down Expand Up @@ -69,7 +107,7 @@ func TestOpenV10(t *testing.T) {
config := Config{
MinVersion: Version10,
MaxVersion: Version10,
CipherSuites: []byte{AES_256_GCM, CHACHA20_POLY1305},
CipherSuites: []byte{AES_GCM, CHACHA20_POLY1305},
Key: key,
SequenceNumber: uint32(i), //nolint:gosec // Test loop counter
Rand: rand.Reader,
Expand Down Expand Up @@ -160,7 +198,7 @@ func TestOpenV20(t *testing.T) {
config := Config{
MinVersion: Version20,
MaxVersion: Version20,
CipherSuites: []byte{AES_256_GCM, CHACHA20_POLY1305},
CipherSuites: []byte{AES_GCM, CHACHA20_POLY1305},
Key: key,
SequenceNumber: uint32(i), //nolint:gosec // Test loop counter
Rand: rand.Reader,
Expand Down Expand Up @@ -188,7 +226,7 @@ func TestOpenV20(t *testing.T) {
config := Config{
MinVersion: Version20,
MaxVersion: Version20,
CipherSuites: []byte{AES_256_GCM, CHACHA20_POLY1305},
CipherSuites: []byte{AES_GCM, CHACHA20_POLY1305},
Key: key,
SequenceNumber: uint32(i), //nolint:gosec // Test loop counter
Rand: rand.Reader,
Expand Down
2 changes: 1 addition & 1 deletion fuzz_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -39,7 +39,7 @@ func FuzzEncryptDecrypt(f *testing.F) {
}

// Test both cipher suites
for _, cipher := range []byte{AES_256_GCM, CHACHA20_POLY1305} {
for _, cipher := range []byte{AES_GCM, CHACHA20_POLY1305} {
config := Config{
Key: key[:],
CipherSuites: []byte{cipher},
Expand Down
37 changes: 25 additions & 12 deletions sio.go
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Original file line number Diff line number Diff line change
Expand Up @@ -38,8 +38,8 @@ const (
)

const (
// AES_256_GCM specifies the cipher suite AES-GCM with 256 bit keys.
AES_256_GCM byte = iota
// AES_GCM specifies the cipher suite AES-GCM with 128 or 256 bit keys.
AES_GCM byte = iota
// CHACHA20_POLY1305 specifies the cipher suite ChaCha20Poly1305 with 256 bit keys.
CHACHA20_POLY1305
)
Expand All @@ -66,8 +66,6 @@ func detectAESSupport() bool {
}

const (
keySize = 32

headerSize = 16
maxPayloadSize = 1 << 16
tagSize = 16
Expand All @@ -77,17 +75,32 @@ const (
maxEncryptedSize = maxDecryptedSize + ((headerSize + tagSize) * 1 << 32)
)

var newAesGcm = func(key []byte) (cipher.AEAD, error) {
aes256, err := aes.NewCipher(key)
var newAES = func(key []byte) (cipher.AEAD, error) {
block, err := aes.NewCipher(key)
if err != nil {
return nil, err
}
return cipher.NewGCM(aes256)
return cipher.NewGCM(block)
}

var newChaCha20 = func(key []byte) (cipher.AEAD, error) {
// ChaCha20 requires 256 bit keys. When a 128 bit key K128 is
// provided, we expand it to a 256 bit key K256 = K128 | K128.
// This is acceptable for ChaCha20 since it has no other requirements
// on its key apart from being 256 bit long and unknown to resp.
// unpredictable for an adversary.
if len(key) == 128/8 {
k := make([]byte, 0, 256/8)
k = append(k, key...)
k = append(k, key...)
key = k
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}
return chacha20poly1305.New(key)
}

var supportedCiphers = [...]func([]byte) (cipher.AEAD, error){
AES_256_GCM: newAesGcm,
CHACHA20_POLY1305: chacha20poly1305.New,
AES_GCM: newAES,
CHACHA20_POLY1305: newChaCha20,
}

var (
Expand Down Expand Up @@ -336,9 +349,9 @@ func DecryptWriter(dst io.Writer, config Config) (io.WriteCloser, error) {

func defaultCipherSuites() []byte {
if supportsAES {
return []byte{AES_256_GCM, CHACHA20_POLY1305}
return []byte{AES_GCM, CHACHA20_POLY1305}
}
return []byte{CHACHA20_POLY1305, AES_256_GCM}
return []byte{CHACHA20_POLY1305, AES_GCM}
}

func setConfigDefaults(config *Config) error {
Expand All @@ -348,7 +361,7 @@ func setConfigDefaults(config *Config) error {
if config.MaxVersion > Version20 {
return errors.New("sio: unknown maximum version")
}
if len(config.Key) != keySize {
if len(config.Key) != 128/8 && len(config.Key) != 256/8 {
return errors.New("sio: invalid key size")
}
if len(config.CipherSuites) > 2 {
Expand Down
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