Simplify the wrapper around the c-kzg library (#6530)

gradle/versions.gradle

@@ -41,6 +41,7 @@ dependencyManagement {
 
     dependency 'io.libp2p:jvm-libp2p-minimal:0.10.0-RELEASE'
     dependency 'tech.pegasys:jblst:0.3.8'
+    dependency 'tech.pegasys:jc-kzg-4844:develop'
 
     dependency 'org.hdrhistogram:HdrHistogram:2.1.12'
 

infrastructure/kzg/build.gradle

@@ -1,12 +1,8 @@
-repositories {
-  maven { url "https://artifacts.consensys.net/public/maven/maven/" }
-}
-
 dependencies {
+  implementation project(':infrastructure:io')
+
   implementation 'org.apache.tuweni:tuweni-bytes'
   implementation 'org.apache.tuweni:tuweni-ssz'
-  implementation("tech.pegasys:jc-kzg-4844:develop")
+  implementation 'tech.pegasys:jc-kzg-4844'
   implementation 'commons-io:commons-io'
-
-  implementation project(":infrastructure:io")
 }

infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZG.java

@@ -13,119 +13,66 @@
 
 package tech.pegasys.teku.kzg;
 
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.net.URISyntaxException;
 import java.net.URL;
-import java.nio.file.Paths;
 import java.util.List;
-import org.apache.logging.log4j.LogManager;
-import org.apache.logging.log4j.Logger;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
-import tech.pegasys.teku.infrastructure.io.resource.ResourceLoader;
-import tech.pegasys.teku.kzg.impl.KZG4844;
-import tech.pegasys.teku.kzg.impl.KzgException;
-import tech.pegasys.teku.kzg.impl.ckzg.CkzgLoader;
 
 /**
- * Implements the standard KZG functions needed for the EIP-4844 specification.
- *
- * <p>This package strives to implement the KZG standard as used in the Eth2 specification and is
- * the entry-point for all KZG operations in Teku. Do not rely on any of the classes used by this
- * one conforming to the specification or standard.
+ * This interface specifies all the KZG functions needed for the EIP-4844 specification and is the
+ * entry-point for all KZG operations in Teku.
  */
-public final class KZG {
-  private static final Logger LOG = LogManager.getLogger();
-  private static final String FILE_SCHEME = "file";
-
-  private static KZG4844 kzgImpl;
-
-  static {
-    resetKzgImplementation();
-  }
-
-  public static void setKzgImplementation(final KZG4844 kzgImpl) {
-    KZG.kzgImpl = kzgImpl;
-  }
-
-  public static void resetKzgImplementation() {
-    if (CkzgLoader.INSTANCE.isPresent()) {
-      kzgImpl = CkzgLoader.INSTANCE.get();
-      LOG.info("KZG: loaded CKZG library");
-    } else {
-      throw new KzgException("Failed to load CKZG library.");
-    }
-  }
-
-  public static KZG4844 getKzgImpl() {
-    return kzgImpl;
-  }
-
-  public static void resetTrustedSetup() {
-    try {
-      kzgImpl.resetTrustedSetup();
-    } catch (final KzgException ex) {
-      LOG.trace("Trying to reset KZG trusted setup which is not loaded");
-    }
-  }
-
-  public static void loadTrustedSetup(final URL url) {
-    final String filePath;
-    try {
-      filePath = copyResourceToTempFileIfNeeded(url);
-    } catch (final IOException ex) {
-      throw new KzgException(
-          String.format("Failed to copy trusted setup '%s' to temporary file", url), ex);
-    }
-    kzgImpl.loadTrustedSetup(filePath);
-  }
-
-  public static KZGProof computeAggregateKzgProof(final List<Bytes> blobs) {
-    return kzgImpl.computeAggregateKzgProof(blobs);
-  }
-
-  public static boolean verifyAggregateKzgProof(
-      final List<Bytes> blobs, final List<KZGCommitment> kzgCommitments, final KZGProof kzgProof) {
-    return kzgImpl.verifyAggregateKzgProof(blobs, kzgCommitments, kzgProof);
-  }
-
-  public static KZGCommitment blobToKzgCommitment(final Bytes blob) {
-    return kzgImpl.blobToKzgCommitment(blob);
-  }
-
-  public static boolean verifyKzgProof(
-      final KZGCommitment kzgCommitment,
-      final Bytes32 z,
-      final Bytes32 y,
-      final KZGProof kzgProof) {
-    return kzgImpl.verifyKzgProof(kzgCommitment, z, y, kzgProof);
-  }
-
-  private static String copyResourceToTempFileIfNeeded(final URL url) throws IOException {
-    try {
-      if (url.toURI().getScheme().equals(FILE_SCHEME)) {
-        // Platform-agnostic safe way to get path
-        return Paths.get(url.toURI()).toFile().getPath();
-      }
-    } catch (final URISyntaxException ex) {
-      throw new KzgException(String.format("%s is incorrect file path", url), ex);
-    }
-
-    final Bytes resource =
-        ResourceLoader.urlOrFile("application/octet-stream")
-            .loadBytes(url.toExternalForm())
-            .orElseThrow(() -> new FileNotFoundException("Not found"));
-
-    File temp = File.createTempFile("resource", ".tmp");
-    temp.deleteOnExit();
-
-    try (final FileOutputStream out = new FileOutputStream(temp)) {
-      out.write(resource.toArray());
-    }
-
-    return temp.getAbsolutePath();
-  }
+public interface KZG {
+
+  KZG NOOP =
+      new KZG() {
+        @Override
+        public void loadTrustedSetup(final URL trustedSetup) throws KZGException {}
+
+        @Override
+        public void freeTrustedSetup() throws KZGException {}
+
+        @Override
+        public KZGProof computeAggregateKzgProof(final List<Bytes> blobs) throws KZGException {
+          return KZGProof.infinity();
+        }
+
+        @Override
+        public boolean verifyAggregateKzgProof(
+            final List<Bytes> blobs,
+            final List<KZGCommitment> kzgCommitments,
+            final KZGProof kzgProof)
+            throws KZGException {
+          return true;
+        }
+
+        @Override
+        public KZGCommitment blobToKzgCommitment(final Bytes blob) throws KZGException {
+          return KZGCommitment.infinity();
+        }
+
+        @Override
+        public boolean verifyKzgProof(
+            final KZGCommitment kzgCommitment,
+            final Bytes32 z,
+            final Bytes32 y,
+            final KZGProof kzgProof)
+            throws KZGException {
+          return true;
+        }
+      };
+
+  void loadTrustedSetup(URL trustedSetup) throws KZGException;
+
+  void freeTrustedSetup() throws KZGException;
+
+  KZGProof computeAggregateKzgProof(List<Bytes> blobs) throws KZGException;
+
+  boolean verifyAggregateKzgProof(
+      List<Bytes> blobs, List<KZGCommitment> kzgCommitments, KZGProof kzgProof) throws KZGException;
+
+  KZGCommitment blobToKzgCommitment(Bytes blob) throws KZGException;
+
+  boolean verifyKzgProof(KZGCommitment kzgCommitment, Bytes32 z, Bytes32 y, KZGProof kzgProof)
+      throws KZGException;
 }

infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGCommitment.java

@@ -47,11 +47,14 @@ public static KZGCommitment fromSSZBytes(final Bytes bytes) {
         reader -> new KZGCommitment(Bytes48.wrap(reader.readFixedBytes(KZG_COMMITMENT_SIZE))));
   }
 
-  public static KZGCommitment fromBytesCompressed(final Bytes48 bytes)
-      throws IllegalArgumentException {
+  public static KZGCommitment fromBytesCompressed(final Bytes48 bytes) {
     return new KZGCommitment(bytes);
   }
 
+  public static KZGCommitment fromArray(final byte[] bytes) {
+    return fromBytesCompressed(Bytes48.wrap(bytes));
+  }
+
   private final Bytes48 bytesCompressed;
 
   public KZGCommitment(final Bytes48 bytesCompressed) {
@@ -71,6 +74,10 @@ public Bytes48 getBytesCompressed() {
     return bytesCompressed;
   }
 
+  public byte[] toArray() {
+    return bytesCompressed.toArray();
+  }
+
   public String toAbbreviatedString() {
     return getBytesCompressed().toUnprefixedHexString().substring(0, 7);
   }
@@ -98,7 +105,7 @@ public boolean equals(final Object obj) {
       return false;
     }
 
-    KZGCommitment other = (KZGCommitment) obj;
+    final KZGCommitment other = (KZGCommitment) obj;
     return Objects.equals(this.getBytesCompressed(), other.getBytesCompressed());
   }
 

infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/impl/KzgException.java → infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGException.java

@@ -11,15 +11,15 @@
  * specific language governing permissions and limitations under the License.
  */
 
-package tech.pegasys.teku.kzg.impl;
+package tech.pegasys.teku.kzg;
 
-public class KzgException extends IllegalArgumentException {
+public class KZGException extends RuntimeException {
 
-  public KzgException(String message) {
+  public KZGException(final String message) {
     super(message);
   }
 
-  public KzgException(String message, Throwable cause) {
+  public KZGException(final String message, final Throwable cause) {
     super(message, cause);
   }
 }

infrastructure/kzg/src/main/java/tech/pegasys/teku/kzg/KZGProof.java

@@ -50,16 +50,20 @@ public static KZGProof fromBytesCompressed(final Bytes48 bytes) throws IllegalAr
     return new KZGProof(bytes);
   }
 
+  public static KZGProof fromArray(final byte[] bytes) {
+    return fromBytesCompressed(Bytes48.wrap(bytes));
+  }
+
   private final Bytes48 bytesCompressed;
 
   public KZGProof(final Bytes48 bytesCompressed) {
     this.bytesCompressed = bytesCompressed;
   }
 
   /**
-   * Returns the SSZ serialization of the <em>compressed</em> form of the commitment
+   * Returns the SSZ serialization of the <em>compressed</em> form of the proof
    *
-   * @return the serialization of the compressed form of the commitment.
+   * @return the serialization of the compressed form of the proof.
    */
   public Bytes toSSZBytes() {
     return SSZ.encode(writer -> writer.writeFixedBytes(getBytesCompressed()));
@@ -69,6 +73,10 @@ public Bytes48 getBytesCompressed() {
     return bytesCompressed;
   }
 
+  public byte[] toArray() {
+    return bytesCompressed.toArray();
+  }
+
   public String toAbbreviatedString() {
     return getBytesCompressed().toUnprefixedHexString().substring(0, 7);
   }
@@ -96,7 +104,7 @@ public boolean equals(final Object obj) {
       return false;
     }
 
-    KZGProof other = (KZGProof) obj;
+    final KZGProof other = (KZGProof) obj;
     return Objects.equals(this.getBytesCompressed(), other.getBytesCompressed());
   }