EC updates from bc-csharp

peterdettman · peterdettman · commit 2aebe154b24e · 2024-04-26T18:42:21.000+07:00
diff --git a/core/src/main/java/org/bouncycastle/asn1/x9/X9IntegerConverter.java b/core/src/main/java/org/bouncycastle/asn1/x9/X9IntegerConverter.java
@@ -17,10 +17,9 @@ public class X9IntegerConverter
      * @param c the curve of interest.
      * @return the field size in bytes (rounded up).
      */
-    public int getByteLength(
-        ECCurve c)
+    public int getByteLength(ECCurve c)
     {
-        return (c.getFieldSize() + 7) / 8;
+        return c.getFieldElementEncodingLength();
     }
 
     /**
@@ -29,10 +28,9 @@ public int getByteLength(
      * @param fe the field element of interest.
      * @return the field size in bytes (rounded up).
      */
-    public int getByteLength(
-        ECFieldElement fe)
+    public int getByteLength(ECFieldElement fe)
     {
-        return (fe.getFieldSize() + 7) / 8;
+        return fe.getEncodedLength();
     }
 
     /**
diff --git a/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHBasicAgreement.java b/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHBasicAgreement.java
@@ -41,7 +41,7 @@ public void init(
 
     public int getFieldSize()
     {
-        return (key.getParameters().getCurve().getFieldSize() + 7) / 8;
+        return key.getParameters().getCurve().getFieldElementEncodingLength();
     }
 
     public BigInteger calculateAgreement(
diff --git a/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHCBasicAgreement.java b/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHCBasicAgreement.java
@@ -45,7 +45,7 @@ public void init(
 
     public int getFieldSize()
     {
-        return (key.getParameters().getCurve().getFieldSize() + 7) / 8;
+        return key.getParameters().getCurve().getFieldElementEncodingLength();
     }
 
     public BigInteger calculateAgreement(
diff --git a/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHCStagedAgreement.java b/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHCStagedAgreement.java
@@ -27,7 +27,7 @@ public void init(
 
     public int getFieldSize()
     {
-        return (key.getParameters().getCurve().getFieldSize() + 7) / 8;
+        return key.getParameters().getCurve().getFieldElementEncodingLength();
     }
 
     public AsymmetricKeyParameter calculateStage(
diff --git a/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHCUnifiedAgreement.java b/core/src/main/java/org/bouncycastle/crypto/agreement/ECDHCUnifiedAgreement.java
@@ -25,7 +25,7 @@ public void init(
 
     public int getFieldSize()
     {
-        return (privParams.getStaticPrivateKey().getParameters().getCurve().getFieldSize() + 7) / 8;
+        return privParams.getStaticPrivateKey().getParameters().getCurve().getFieldElementEncodingLength();
     }
 
     public byte[] calculateAgreement(CipherParameters pubKey)
diff --git a/core/src/main/java/org/bouncycastle/crypto/agreement/ECMQVBasicAgreement.java b/core/src/main/java/org/bouncycastle/crypto/agreement/ECMQVBasicAgreement.java
@@ -31,7 +31,7 @@ public void init(
 
     public int getFieldSize()
     {
-        return (privParams.getStaticPrivateKey().getParameters().getCurve().getFieldSize() + 7) / 8;
+        return privParams.getStaticPrivateKey().getParameters().getCurve().getFieldElementEncodingLength();
     }
 
     public BigInteger calculateAgreement(CipherParameters pubKey)
diff --git a/core/src/main/java/org/bouncycastle/crypto/agreement/ECVKOAgreement.java b/core/src/main/java/org/bouncycastle/crypto/agreement/ECVKOAgreement.java
@@ -48,7 +48,7 @@ public int getAgreementSize()
      */
     public int getFieldSize()
     {
-        return (key.getParameters().getCurve().getFieldSize() + 7) / 8;
+        return key.getParameters().getCurve().getFieldElementEncodingLength();
     }
 
     public byte[] calculateAgreement(CipherParameters pubKey)
diff --git a/core/src/main/java/org/bouncycastle/crypto/engines/SM2Engine.java b/core/src/main/java/org/bouncycastle/crypto/engines/SM2Engine.java
@@ -95,7 +95,7 @@ public void init(boolean forEncryption, CipherParameters param)
             ecParams = ecKey.getParameters();
         }
 
-        curveLength = (ecParams.getCurve().getFieldSize() + 7) / 8;
+        curveLength = ecParams.getCurve().getFieldElementEncodingLength();
 
         CryptoServicesRegistrar.checkConstraints(new DefaultServiceProperties("SM2", ConstraintUtils.bitsOfSecurityFor(ecParams.getCurve()), ecKey, Utils.getPurpose(forEncryption)));
     }
diff --git a/core/src/main/java/org/bouncycastle/crypto/kems/ECIESKEMExtractor.java b/core/src/main/java/org/bouncycastle/crypto/kems/ECIESKEMExtractor.java
@@ -119,6 +119,6 @@ public byte[] extractSecret(byte[] encapsulation)
 
     public int getEncapsulationLength()
     {
-        return (decKey.getParameters().getCurve().getFieldSize() / 8) * 2 + 1;
+        return decKey.getParameters().getCurve().getAffinePointEncodingLength(false);
     }
 }
diff --git a/core/src/main/java/org/bouncycastle/crypto/parsers/ECIESPublicKeyParser.java b/core/src/main/java/org/bouncycastle/crypto/parsers/ECIESPublicKeyParser.java
@@ -1,12 +1,14 @@
 package org.bouncycastle.crypto.parsers;
 
+import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 
 import org.bouncycastle.crypto.KeyParser;
 import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
 import org.bouncycastle.crypto.params.ECDomainParameters;
 import org.bouncycastle.crypto.params.ECPublicKeyParameters;
+import org.bouncycastle.math.ec.ECCurve;
 import org.bouncycastle.util.io.Streams;
 
 public class ECIESPublicKeyParser
@@ -22,33 +24,45 @@ public ECIESPublicKeyParser(ECDomainParameters ecParams)
     public AsymmetricKeyParameter readKey(InputStream stream)
         throws IOException
     {
-        byte[] V;
-        int    first = stream.read();
+        int first = stream.read();
+        if (first < 0)
+        {
+            throw new EOFException();
+        }
 
         // Decode the public ephemeral key
+        boolean compressed;
         switch (first)
         {
         case 0x00: // infinity
             throw new IOException("Sender's public key invalid.");
 
         case 0x02: // compressed
         case 0x03: // Byte length calculated as in ECPoint.getEncoded();
-            V = new byte[1 + (ecParams.getCurve().getFieldSize()+7)/8];
+            compressed = true;
             break;
 
         case 0x04: // uncompressed or
         case 0x06: // hybrid
         case 0x07: // Byte length calculated as in ECPoint.getEncoded();
-            V = new byte[1 + 2*((ecParams.getCurve().getFieldSize()+7)/8)];
+            compressed = false;
             break;
 
         default:
             throw new IOException("Sender's public key has invalid point encoding 0x" + Integer.toString(first, 16));
         }
 
+        ECCurve curve = ecParams.getCurve();
+        int encodingLength = curve.getAffinePointEncodingLength(compressed);
+        byte[] V = new byte[encodingLength];
         V[0] = (byte)first;
-        Streams.readFully(stream, V, 1, V.length - 1);
 
-        return new ECPublicKeyParameters(ecParams.getCurve().decodePoint(V), ecParams);
+        int readLength = encodingLength - 1;
+        if (Streams.readFully(stream, V, 1, readLength) != readLength)
+        {
+            throw new EOFException();
+        }
+
+        return new ECPublicKeyParameters(curve.decodePoint(V), ecParams);
     }
 }
diff --git a/core/src/main/java/org/bouncycastle/math/ec/ECCurve.java b/core/src/main/java/org/bouncycastle/math/ec/ECCurve.java
@@ -123,6 +123,19 @@ public synchronized Config configure()
         return new Config(this.coord, this.endomorphism, this.multiplier);
     }
 
+    public int getFieldElementEncodingLength()
+    {
+        return (getFieldSize() + 7) / 8;
+    }
+
+    public int getAffinePointEncodingLength(boolean compressed)
+    {
+        int fieldLength = getFieldElementEncodingLength();
+        return compressed
+            ?  1 + fieldLength
+            :  1 + fieldLength * 2;
+    }
+
     public ECPoint validatePoint(BigInteger x, BigInteger y)
     {
         ECPoint p = createPoint(x, y);
@@ -379,7 +392,7 @@ public ECMultiplier getMultiplier()
     public ECPoint decodePoint(byte[] encoded)
     {
         ECPoint p = null;
-        int expectedLength = (getFieldSize() + 7) / 8;
+        int expectedLength = getFieldElementEncodingLength();
 
         byte type = encoded[0];
         switch (type)
@@ -463,25 +476,15 @@ public ECPoint decodePoint(byte[] encoded)
      */
     public ECLookupTable createCacheSafeLookupTable(final ECPoint[] points, int off, final int len)
     {
-        final int FE_BYTES = (getFieldSize() + 7) >>> 3;
-
+        final int FE_BYTES = getFieldElementEncodingLength();
         final byte[] table = new byte[len * FE_BYTES * 2];
+        int pos = 0;
+        for (int i = 0; i < len; ++i)
         {
-            int pos = 0;
-            for (int i = 0; i < len; ++i)
-            {
-                ECPoint p = points[off + i];
-                byte[] px = p.getRawXCoord().toBigInteger().toByteArray();
-                byte[] py = p.getRawYCoord().toBigInteger().toByteArray();
-
-                int pxStart = px.length > FE_BYTES ? 1 : 0, pxLen = px.length - pxStart;
-                int pyStart = py.length > FE_BYTES ? 1 : 0, pyLen = py.length - pyStart;
-
-                System.arraycopy(px, pxStart, table, pos + FE_BYTES - pxLen, pxLen); pos += FE_BYTES;
-                System.arraycopy(py, pyStart, table, pos + FE_BYTES - pyLen, pyLen); pos += FE_BYTES;
-            }
+            ECPoint p = points[off + i];
+            p.getRawXCoord().encodeTo(table, pos);      pos += FE_BYTES;
+            p.getRawYCoord().encodeTo(table, pos);      pos += FE_BYTES;
         }
-
         return new AbstractECLookupTable()
         {
             public int getSize()
diff --git a/core/src/main/java/org/bouncycastle/math/ec/ECFieldElement.java b/core/src/main/java/org/bouncycastle/math/ec/ECFieldElement.java
@@ -85,7 +85,17 @@ public String toString()
 
     public byte[] getEncoded()
     {
-        return BigIntegers.asUnsignedByteArray((getFieldSize() + 7) / 8, toBigInteger());
+        return BigIntegers.asUnsignedByteArray(getEncodedLength(), toBigInteger());
+    }
+
+    public int getEncodedLength()
+    {
+        return (getFieldSize() + 7) / 8;
+    }
+
+    public void encodeTo(byte[] buf, int off)
+    {
+        BigIntegers.asUnsignedByteArray(toBigInteger(), buf, off, getEncodedLength());
     }
 
     public static abstract class AbstractFp extends ECFieldElement
diff --git a/core/src/main/java/org/bouncycastle/math/ec/ECPoint.java b/core/src/main/java/org/bouncycastle/math/ec/ECPoint.java
@@ -501,11 +501,51 @@ public byte[] getEncoded(boolean compressed)
 
         byte[] Y = normed.getYCoord().getEncoded();
 
-        byte[] PO = new byte[X.length + Y.length + 1];
-        PO[0] = 0x04;
-        System.arraycopy(X, 0, PO, 1, X.length);
-        System.arraycopy(Y, 0, PO, X.length + 1, Y.length);
-        return PO;
+        {
+            byte[] PO = new byte[X.length + Y.length + 1];
+            PO[0] = 0x04;
+            System.arraycopy(X, 0, PO, 1, X.length);
+            System.arraycopy(Y, 0, PO, X.length + 1, Y.length);
+            return PO;
+        }
+    }
+
+    public int getEncodedLength(boolean compressed)
+    {
+        if (isInfinity())
+        {
+            return 1;
+        }
+
+        if (compressed)
+        {
+            return 1 + getXCoord().getEncodedLength();
+        }
+
+        return 1 + getXCoord().getEncodedLength() + getYCoord().getEncodedLength();
+    }
+
+    public void encodeTo(boolean compressed, byte[] buf, int off)
+    {
+        if (isInfinity())
+        {
+            buf[off] = 0x00;
+            return;
+        }
+
+        ECPoint normed = normalize();
+        ECFieldElement X = normed.getXCoord(), Y = normed.getYCoord();
+
+        if (compressed)
+        {
+            buf[off] = (byte)(normed.getCompressionYTilde() ? 0x03 : 0x02);
+            X.encodeTo(buf, off + 1);
+            return;
+        }
+
+        buf[off] = 0x04;
+        X.encodeTo(buf, off + 1);
+        Y.encodeTo(buf, off + 1 + X.getEncodedLength());
     }
 
     protected abstract boolean getCompressionYTilde();

Original file line number	Diff line number	Diff line change
`@@ -17,10 +17,9 @@ public class X9IntegerConverter`
`17`	`17`	`* @param c the curve of interest.`
`18`	`18`	`* @return the field size in bytes (rounded up).`
`19`	`19`	`*/`
`20`		`- public int getByteLength(`
`21`		`- ECCurve c)`
	`20`	`+ public int getByteLength(ECCurve c)`
`22`	`21`	`{`
`23`		`- return (c.getFieldSize() + 7) / 8;`
	`22`	`+ return c.getFieldElementEncodingLength();`
`24`	`23`	`}`
`25`	`24`
`26`	`25`	`/**`
`@@ -29,10 +28,9 @@ public int getByteLength(`
`29`	`28`	`* @param fe the field element of interest.`
`30`	`29`	`* @return the field size in bytes (rounded up).`
`31`	`30`	`*/`
`32`		`- public int getByteLength(`
`33`		`- ECFieldElement fe)`
	`31`	`+ public int getByteLength(ECFieldElement fe)`
`34`	`32`	`{`
`35`		`- return (fe.getFieldSize() + 7) / 8;`
	`33`	`+ return fe.getEncodedLength();`
`36`	`34`	`}`
`37`	`35`
`38`	`36`	`/**`
Original file line number	Diff line number	Diff line change
`@@ -41,7 +41,7 @@ public void init(`
`41`	`41`
`42`	`42`	`public int getFieldSize()`
`43`	`43`	`{`
`44`		`- return (key.getParameters().getCurve().getFieldSize() + 7) / 8;`
	`44`	`+ return key.getParameters().getCurve().getFieldElementEncodingLength();`
`45`	`45`	`}`
`46`	`46`
`47`	`47`	`public BigInteger calculateAgreement(`
Original file line number	Diff line number	Diff line change
`@@ -45,7 +45,7 @@ public void init(`
`45`	`45`
`46`	`46`	`public int getFieldSize()`
`47`	`47`	`{`
`48`		`- return (key.getParameters().getCurve().getFieldSize() + 7) / 8;`
	`48`	`+ return key.getParameters().getCurve().getFieldElementEncodingLength();`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`public BigInteger calculateAgreement(`
Original file line number	Diff line number	Diff line change
`@@ -27,7 +27,7 @@ public void init(`
`27`	`27`
`28`	`28`	`public int getFieldSize()`
`29`	`29`	`{`
`30`		`- return (key.getParameters().getCurve().getFieldSize() + 7) / 8;`
	`30`	`+ return key.getParameters().getCurve().getFieldElementEncodingLength();`
`31`	`31`	`}`
`32`	`32`
`33`	`33`	`public AsymmetricKeyParameter calculateStage(`
Original file line number	Diff line number	Diff line change
`@@ -25,7 +25,7 @@ public void init(`
`25`	`25`
`26`	`26`	`public int getFieldSize()`
`27`	`27`	`{`
`28`		`- return (privParams.getStaticPrivateKey().getParameters().getCurve().getFieldSize() + 7) / 8;`
	`28`	`+ return privParams.getStaticPrivateKey().getParameters().getCurve().getFieldElementEncodingLength();`
`29`	`29`	`}`
`30`	`30`
`31`	`31`	`public byte[] calculateAgreement(CipherParameters pubKey)`
Original file line number	Diff line number	Diff line change
`@@ -31,7 +31,7 @@ public void init(`
`31`	`31`
`32`	`32`	`public int getFieldSize()`
`33`	`33`	`{`
`34`		`- return (privParams.getStaticPrivateKey().getParameters().getCurve().getFieldSize() + 7) / 8;`
	`34`	`+ return privParams.getStaticPrivateKey().getParameters().getCurve().getFieldElementEncodingLength();`
`35`	`35`	`}`
`36`	`36`
`37`	`37`	`public BigInteger calculateAgreement(CipherParameters pubKey)`
Original file line number	Diff line number	Diff line change
`@@ -48,7 +48,7 @@ public int getAgreementSize()`
`48`	`48`	`*/`
`49`	`49`	`public int getFieldSize()`
`50`	`50`	`{`
`51`		`- return (key.getParameters().getCurve().getFieldSize() + 7) / 8;`
	`51`	`+ return key.getParameters().getCurve().getFieldElementEncodingLength();`
`52`	`52`	`}`
`53`	`53`
`54`	`54`	`public byte[] calculateAgreement(CipherParameters pubKey)`
Original file line number	Diff line number	Diff line change
`@@ -95,7 +95,7 @@ public void init(boolean forEncryption, CipherParameters param)`
`95`	`95`	`ecParams = ecKey.getParameters();`
`96`	`96`	`}`
`97`	`97`
`98`		`- curveLength = (ecParams.getCurve().getFieldSize() + 7) / 8;`
	`98`	`+ curveLength = ecParams.getCurve().getFieldElementEncodingLength();`
`99`	`99`
`100`	`100`	`CryptoServicesRegistrar.checkConstraints(new DefaultServiceProperties("SM2", ConstraintUtils.bitsOfSecurityFor(ecParams.getCurve()), ecKey, Utils.getPurpose(forEncryption)));`
`101`	`101`	`}`
Original file line number	Diff line number	Diff line change
`@@ -119,6 +119,6 @@ public byte[] extractSecret(byte[] encapsulation)`
`119`	`119`
`120`	`120`	`public int getEncapsulationLength()`
`121`	`121`	`{`
`122`		`- return (decKey.getParameters().getCurve().getFieldSize() / 8) * 2 + 1;`
	`122`	`+ return decKey.getParameters().getCurve().getAffinePointEncodingLength(false);`
`123`	`123`	`}`
`124`	`124`	`}`