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8375275: Error handling to raise illegal_parameter or internal_error alert in hybrid key exchange #665

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8375275: Error handling to raise illegal_parameter or internal_error alert in hybrid key exchange #665

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37 changes: 35 additions & 2 deletions src/java.base/share/classes/sun/security/ssl/DHasKEM.java
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2025, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2025, 2026, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand Down Expand Up @@ -101,7 +101,18 @@ public KEM.Encapsulated engineEncapsulate(int from, int to,
return new KEM.Encapsulated(
sub(dh, from, to),
pkEm, null);

} catch (IllegalArgumentException e) {
// ECDH validation failure
// all-zero shared secret
throw e;
} catch (InvalidKeyException e) {
// Invalid peer public key
// Convert InvalidKeyException to an unchecked exception
throw new IllegalArgumentException("Invalid peer public key",
e);
} catch (Exception e) {
// Unexpected internal failure
throw new ProviderException("internal error", e);
}
}
Expand All @@ -126,6 +137,11 @@ public SecretKey engineDecapsulate(byte[] encapsulation, int from,
PublicKey pkE = params.DeserializePublicKey(encapsulation);
SecretKey dh = params.DH(algorithm, skR, pkE);
return sub(dh, from, to);

} catch (IllegalArgumentException e) {
// ECDH validation failure
// all-zero shared secret
throw e;
} catch (IOException | InvalidKeyException e) {
throw new DecapsulateException("Cannot decapsulate", e);
} catch (Exception e) {
Expand Down Expand Up @@ -248,7 +264,24 @@ private SecretKey DH(String alg, PrivateKey skE, PublicKey pkR)
KeyAgreement ka = KeyAgreement.getInstance(kaAlgorithm);
ka.init(skE);
ka.doPhase(pkR, true);
return ka.generateSecret(alg);
SecretKey secret = ka.generateSecret(alg);

// RFC 8446 section 7.4.2: checks for all-zero
// X25519/X448 shared secret.
if (kaAlgorithm.equals("X25519") ||
kaAlgorithm.equals("X448")) {
byte[] s = secret.getEncoded();
for (byte b : s) {
if (b != 0) {
return secret;
}
}
// Trigger ILLEGAL_PARAMETER alert
throw new IllegalArgumentException(
"All-zero shared secret");
}

return secret;
}
}
}
53 changes: 43 additions & 10 deletions src/java.base/share/classes/sun/security/ssl/KAKeyDerivation.java
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Original file line number Diff line number Diff line change
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2019, 2025, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2019, 2026, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
Expand All @@ -26,6 +26,7 @@

import sun.security.util.RawKeySpec;

import javax.crypto.DecapsulateException;
import javax.crypto.KDF;
import javax.crypto.KEM;
import javax.crypto.KeyAgreement;
Expand All @@ -35,6 +36,7 @@

import java.io.IOException;
import java.security.GeneralSecurityException;
import java.security.InvalidKeyException;
import java.security.KeyFactory;
import java.security.PrivateKey;
import java.security.Provider;
Expand Down Expand Up @@ -173,6 +175,9 @@ KEM.Encapsulated encapsulate(String algorithm, SecureRandom random)
"encapsulation");
}

// All exceptions thrown during KEM encapsulation are mapped
// to TLS fatal alerts:
// illegal_parameter alert or internal_error alert.
try {
KeyFactory kf = (provider != null) ?
KeyFactory.getInstance(algorithmName, provider) :
Expand All @@ -189,8 +194,18 @@ KEM.Encapsulated encapsulate(String algorithm, SecureRandom random)
SecretKey derived = deriveHandshakeSecret(algorithm, sharedSecret);

return new KEM.Encapsulated(derived, enc.encapsulation(), null);
} catch (GeneralSecurityException gse) {
throw new SSLHandshakeException("Could not generate secret", gse);
} catch (IllegalArgumentException | InvalidKeyException e) {
// Peer validation failure
// ECDH all-zero shared secret (RFC 8446 section 7.4.2),
// ML-KEM encapsulation key check failure (FIPS-203 section 7.2)
throw context.conContext.fatal(Alert.ILLEGAL_PARAMETER, e);
} catch (GeneralSecurityException e) {
// Cryptographic failure,
// deriveHandshakeSecret failure.
throw context.conContext.fatal(Alert.INTERNAL_ERROR, e);
} catch (RuntimeException e) {
// unexpected provider/runtime failure
throw context.conContext.fatal(Alert.INTERNAL_ERROR, e);
} finally {
KeyUtil.destroySecretKeys(sharedSecret);
}
Expand All @@ -208,13 +223,30 @@ private SecretKey t13DeriveKey(String type)
// Using KEM: called by the client after receiving the KEM
// ciphertext (keyshare) from the server in ServerHello.
// The client decapsulates it using its private key.
KEM kem = (provider != null)
? KEM.getInstance(algorithmName, provider)
: KEM.getInstance(algorithmName);
var decapsulator = kem.newDecapsulator(localPrivateKey);
sharedSecret = decapsulator.decapsulate(
keyshare, 0, decapsulator.secretSize(),
"TlsPremasterSecret");

// All exceptions thrown during KEM decapsulation are mapped
// to TLS fatal alerts:
// illegal_parameter alert or internal_error alert.
try {
KEM kem = (provider != null)
? KEM.getInstance(algorithmName, provider)
: KEM.getInstance(algorithmName);
var decapsulator = kem.newDecapsulator(localPrivateKey);
sharedSecret = decapsulator.decapsulate(
keyshare, 0, decapsulator.secretSize(),
"TlsPremasterSecret");
} catch (IllegalArgumentException | InvalidKeyException |
DecapsulateException e) {
// Peer validation failure
// ECDH all-zero shared secret (RFC 8446 section 7.4.2)
throw context.conContext.fatal(Alert.ILLEGAL_PARAMETER, e);
} catch (GeneralSecurityException e) {
// cryptographic failure
throw context.conContext.fatal(Alert.INTERNAL_ERROR, e);
} catch (RuntimeException e) {
// unexpected provider/runtime failure
throw context.conContext.fatal(Alert.INTERNAL_ERROR, e);
}
} else {
// Using traditional DH-style Key Agreement
KeyAgreement ka = KeyAgreement.getInstance(algorithmName);
Expand All @@ -225,6 +257,7 @@ private SecretKey t13DeriveKey(String type)

return deriveHandshakeSecret(type, sharedSecret);
} catch (GeneralSecurityException gse) {
// deriveHandshakeSecret() failure
throw new SSLHandshakeException("Could not generate secret", gse);
} finally {
KeyUtil.destroySecretKeys(sharedSecret);
Expand Down