ed25519-java/ed25519-java-CVE-2020-36843.patch

40 lines
1.6 KiB
Diff

--- ed25519-java-0.3.0/src/net/i2p/crypto/eddsa/EdDSAEngine.java 2025-03-14 14:47:43.404137953 +0100
+++ ed25519-java-0.3.0/src/net/i2p/crypto/eddsa/EdDSAEngine.java 2025-03-14 14:50:31.859888550 +0100
@@ -12,6 +12,7 @@
package net.i2p.crypto.eddsa;
import java.io.ByteArrayOutputStream;
+import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
@@ -29,6 +30,7 @@
import net.i2p.crypto.eddsa.math.Curve;
import net.i2p.crypto.eddsa.math.GroupElement;
import net.i2p.crypto.eddsa.math.ScalarOps;
+import net.i2p.crypto.eddsa.math.bigint.BigIntegerLittleEndianEncoding;
/**
* Signing and verification for EdDSA.
@@ -69,6 +71,8 @@
public final class EdDSAEngine extends Signature {
public static final String SIGNATURE_ALGORITHM = "NONEwithEdDSA";
+ private static final BigInteger ORDER = new BigInteger("2").pow(252).add(new BigInteger("27742317777372353535851937790883648493"));
+
private MessageDigest digest;
private ByteArrayOutputStream baos;
private EdDSAKey key;
@@ -306,6 +310,11 @@
h = key.getParams().getScalarOps().reduce(h);
byte[] Sbyte = Arrays.copyOfRange(sigBytes, b/8, b/4);
+ // RFC 8032
+ BigInteger Sbigint = (new BigIntegerLittleEndianEncoding()).toBigInteger(Sbyte);
+ if (Sbigint.compareTo(ORDER) >= 0)
+ return false;
+
// R = SB - H(Rbar,Abar,M)A
GroupElement R = key.getParams().getB().doubleScalarMultiplyVariableTime(
((EdDSAPublicKey) key).getNegativeA(), h, Sbyte);