add rlp decode subcommand (hyperledger#6895)

* add rlp decode subcommand

Signed-off-by: Brindrajsinh-Chauhan <brindrajsinh@gmail.com>

---------

Signed-off-by: Brindrajsinh-Chauhan <brindrajsinh@gmail.com>
Co-authored-by: Sally MacFarlane <macfarla.github@gmail.com>

CHANGELOG.md

@@ -40,6 +40,7 @@
 - Expose transaction count by type metrics for the layered txpool [#6903](https://github.com/hyperledger/besu/pull/6903)
 - Expose bad block events via the BesuEvents plugin API  [#6848](https://github.com/hyperledger/besu/pull/6848)
 - Add RPC errors metric [#6919](https://github.com/hyperledger/besu/pull/6919/)
+- Add `rlp decode` subcommand to decode IBFT/QBFT extraData to validator list [#6895](https://github.com/hyperledger/besu/pull/6895)
 
 ### Bug fixes
 - Fix txpool dump/restore race condition [#6665](https://github.com/hyperledger/besu/pull/6665)

besu/src/main/java/org/hyperledger/besu/cli/subcommands/rlp/IbftExtraDataCLIAdapter.java

@@ -14,6 +14,7 @@
  */
 package org.hyperledger.besu.cli.subcommands.rlp;
 
+import org.hyperledger.besu.consensus.common.bft.BftExtraData;
 import org.hyperledger.besu.consensus.ibft.IbftExtraDataCodec;
 import org.hyperledger.besu.datatypes.Address;
 
@@ -43,4 +44,13 @@ private Bytes fromJsonAddresses(final String jsonAddresses) throws IOException {
     return IbftExtraDataCodec.encodeFromAddresses(
         validatorAddresses.stream().map(Address::fromHexString).collect(Collectors.toList()));
   }
+
+  @Override
+  public BftExtraData decode(final String rlpInput) throws IOException {
+    return fromRLPInput(rlpInput);
+  }
+
+  private BftExtraData fromRLPInput(final String rlpInput) throws IOException {
+    return new IbftExtraDataCodec().decodeRaw(Bytes.fromHexString(rlpInput));
+  }
 }

besu/src/main/java/org/hyperledger/besu/cli/subcommands/rlp/JSONToRLP.java

@@ -14,6 +14,8 @@
  */
 package org.hyperledger.besu.cli.subcommands.rlp;
 
+import org.hyperledger.besu.consensus.common.bft.BftExtraData;
+
 import java.io.IOException;
 
 import org.apache.tuweni.bytes.Bytes;
@@ -29,4 +31,13 @@ interface JSONToRLP {
    * @throws IOException if an error occurs while reading data
    */
   Bytes encode(String json) throws IOException;
+
+  /**
+   * Decodes the input RLP value into a validators list Object.
+   *
+   * @param inputData the RLP hex string to convert to validators list
+   * @return the decoded BFT ExtraData object.
+   * @throws IOException if an error occurs while reading data
+   */
+  BftExtraData decode(String inputData) throws IOException;
 }

besu/src/main/java/org/hyperledger/besu/cli/subcommands/rlp/QbftExtraDataCLIAdapter.java

@@ -14,6 +14,7 @@
  */
 package org.hyperledger.besu.cli.subcommands.rlp;
 
+import org.hyperledger.besu.consensus.common.bft.BftExtraData;
 import org.hyperledger.besu.consensus.qbft.QbftExtraDataCodec;
 import org.hyperledger.besu.datatypes.Address;
 
@@ -40,4 +41,13 @@ private Bytes fromJsonAddresses(final String jsonAddresses) throws IOException {
     return QbftExtraDataCodec.encodeFromAddresses(
         validatorAddresses.stream().map(Address::fromHexString).collect(Collectors.toList()));
   }
+
+  @Override
+  public BftExtraData decode(final String rlpInput) throws IOException {
+    return fromRLPInput(rlpInput);
+  }
+
+  private BftExtraData fromRLPInput(final String rlpInput) throws IOException {
+    return new QbftExtraDataCodec().decodeRaw(Bytes.fromHexString(rlpInput));
+  }
 }

besu/src/main/java/org/hyperledger/besu/cli/subcommands/rlp/RLPSubCommand.java

@@ -19,8 +19,10 @@
 
 import org.hyperledger.besu.cli.BesuCommand;
 import org.hyperledger.besu.cli.DefaultCommandValues;
+import org.hyperledger.besu.cli.subcommands.rlp.RLPSubCommand.DecodeSubCommand;
 import org.hyperledger.besu.cli.subcommands.rlp.RLPSubCommand.EncodeSubCommand;
 import org.hyperledger.besu.cli.util.VersionProvider;
+import org.hyperledger.besu.consensus.common.bft.BftExtraData;
 
 import java.io.BufferedReader;
 import java.io.BufferedWriter;
@@ -30,6 +32,7 @@
 import java.io.PrintWriter;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.NoSuchElementException;
 import java.util.Scanner;
 
 import com.fasterxml.jackson.databind.exc.MismatchedInputException;
@@ -48,7 +51,7 @@
     description = "This command provides RLP data related actions.",
     mixinStandardHelpOptions = true,
     versionProvider = VersionProvider.class,
-    subcommands = {EncodeSubCommand.class})
+    subcommands = {EncodeSubCommand.class, DecodeSubCommand.class})
 public class RLPSubCommand implements Runnable {
 
   /** The constant COMMAND_NAME. */
@@ -207,4 +210,128 @@ private void writeOutput(final Bytes rlpEncodedOutput) {
       }
     }
   }
+
+  /**
+   * RLP decode sub-command
+   *
+   * <p>Decode a RLP hex string into a validator list.
+   */
+  @Command(
+      name = "decode",
+      description = "This command decodes a JSON typed RLP hex string into validator list.",
+      mixinStandardHelpOptions = true,
+      versionProvider = VersionProvider.class)
+  static class DecodeSubCommand implements Runnable {
+
+    @SuppressWarnings("unused")
+    @ParentCommand
+    private RLPSubCommand parentCommand; // Picocli injects reference to parent command
+
+    @SuppressWarnings("unused")
+    @Spec
+    private CommandSpec spec;
+
+    @Option(
+        names = "--type",
+        description =
+            "Type of the RLP data to Decode, possible values are ${COMPLETION-CANDIDATES}. (default: ${DEFAULT-VALUE})",
+        arity = "1..1")
+    private final RLPType type = RLPType.IBFT_EXTRA_DATA;
+
+    @Option(
+        names = "--from",
+        paramLabel = DefaultCommandValues.MANDATORY_FILE_FORMAT_HELP,
+        description = "File containing JSON object to decode",
+        arity = "1..1")
+    private final File jsonSourceFile = null;
+
+    @Option(
+        names = "--to",
+        paramLabel = DefaultCommandValues.MANDATORY_FILE_FORMAT_HELP,
+        description = "File to write decoded RLP string to.",
+        arity = "1..1")
+    private final File rlpTargetFile = null;
+
+    @Override
+    public void run() {
+      checkNotNull(parentCommand);
+      readInput();
+    }
+
+    /**
+     * Reads the stdin or from a file if one is specified by {@link #jsonSourceFile} then goes to
+     * {@link #decode(String)} this data
+     */
+    private void readInput() {
+      // if we have an output file defined, print to it
+      // otherwise print to defined output, usually standard output.
+      final String inputData;
+
+      if (jsonSourceFile != null) {
+        try {
+          BufferedReader reader = Files.newBufferedReader(jsonSourceFile.toPath(), UTF_8);
+
+          // Read only the first line if there are many lines
+          inputData = reader.readLine();
+        } catch (IOException e) {
+          throw new ExecutionException(spec.commandLine(), "Unable to read input file.");
+        }
+      } else {
+        // get data from standard input
+        try (Scanner scanner = new Scanner(parentCommand.in, UTF_8.name())) {
+          inputData = scanner.nextLine();
+        } catch (NoSuchElementException e) {
+          throw new ParameterException(spec.commandLine(), "Unable to read input data." + e);
+        }
+      }
+
+      decode(inputData);
+    }
+
+    /**
+     * Decodes the string input into an validator data based on the {@link #type} then goes to
+     * {@link #writeOutput(BftExtraData)} this data to file or stdout
+     *
+     * @param inputData the string data to decode
+     */
+    private void decode(final String inputData) {
+      if (inputData == null || inputData.isEmpty()) {
+        throw new ParameterException(
+            spec.commandLine(), "An error occurred while trying to read the input data.");
+      } else {
+        try {
+          // decode and write the value
+          writeOutput(type.getAdapter().decode(inputData));
+        } catch (MismatchedInputException e) {
+          throw new ParameterException(
+              spec.commandLine(),
+              "Unable to map the input data with selected type. Please check input format. " + e);
+        } catch (IOException e) {
+          throw new ParameterException(
+              spec.commandLine(), "Unable to load the input data. Please check input format. " + e);
+        }
+      }
+    }
+
+    /**
+     * write the decoded result to stdout or a file if the option is specified
+     *
+     * @param bftExtraDataOutput the BFT extra data output to write to file or stdout
+     */
+    private void writeOutput(final BftExtraData bftExtraDataOutput) {
+      if (rlpTargetFile != null) {
+        final Path targetPath = rlpTargetFile.toPath();
+
+        try (final BufferedWriter fileWriter = Files.newBufferedWriter(targetPath, UTF_8)) {
+          fileWriter.write(bftExtraDataOutput.getValidators().toString());
+        } catch (final IOException e) {
+          throw new ParameterException(
+              spec.commandLine(),
+              "An error occurred while trying to write the validator list. " + e.getMessage());
+        }
+      } else {
+        parentCommand.out.println(bftExtraDataOutput.getValidators().toString());
+      }
+    }
+  }
 }

besu/src/test/java/org/hyperledger/besu/cli/subcommands/rlp/RLPSubCommandTest.java

@@ -68,6 +68,7 @@ public class RLPSubCommandTest extends CommandTestAbstract {
 
   private static final String RLP_SUBCOMMAND_NAME = "rlp";
   private static final String RLP_ENCODE_SUBCOMMAND_NAME = "encode";
+  private static final String RLP_DECODE_SUBCOMMAND_NAME = "decode";
   private static final String RLP_QBFT_TYPE = "QBFT_EXTRA_DATA";
 
   // RLP sub-command
@@ -259,6 +260,157 @@ public void encodeWithEmptyStdInputMustRaiseAnError() throws Exception {
         .startsWith("An error occurred while trying to read the JSON data.");
   }
 
+  @Test
+  public void decodeWithoutPathMustWriteToStandardOutput() {
+
+    final String inputData =
+        "0xf853a00000000000000000000000000000000000000000000000000000000000000000ea94be068f726a13c8d"
+            + "46c44be6ce9d275600e1735a4945ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193808400000000c0";
+
+    // set stdin
+    final ByteArrayInputStream stdIn = new ByteArrayInputStream(inputData.getBytes(UTF_8));
+
+    parseCommand(stdIn, RLP_SUBCOMMAND_NAME, RLP_DECODE_SUBCOMMAND_NAME);
+
+    final String expectedValidatorString =
+        "[0xbe068f726a13c8d46c44be6ce9d275600e1735a4, 0x5ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193]";
+    assertThat(commandOutput.toString(UTF_8)).contains(expectedValidatorString);
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
+  @Test
+  public void decodeQBFTWithoutPathMustWriteToStandardOutput() {
+
+    final String inputData =
+        "0xf84fa00000000000000000000000000000000000000000000000000000000000000000ea94241f804efb46f71acaa"
+            + "5be94a62f7798e89c3724946cdf72da457453063ea92e7fa5ac30afbcec28cdc080c0";
+
+    // set stdin
+    final ByteArrayInputStream stdIn = new ByteArrayInputStream(inputData.getBytes(UTF_8));
+
+    parseCommand(stdIn, RLP_SUBCOMMAND_NAME, RLP_DECODE_SUBCOMMAND_NAME, "--type", RLP_QBFT_TYPE);
+
+    final String expectedValidatorString =
+        "[0x241f804efb46f71acaa5be94a62f7798e89c3724, 0x6cdf72da457453063ea92e7fa5ac30afbcec28cd]";
+    assertThat(commandOutput.toString(UTF_8)).contains(expectedValidatorString);
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
+  @Test
+  public void decodeWithOutputFileMustWriteInThisFile() throws Exception {
+
+    final File file = File.createTempFile("ibftValidators", "rlp");
+
+    final String inputData =
+        "0xf853a00000000000000000000000000000000000000000000000000000000000000000ea94be068f726a13c8d"
+            + "46c44be6ce9d275600e1735a4945ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193808400000000c0";
+
+    // set stdin
+    final ByteArrayInputStream stdIn = new ByteArrayInputStream(inputData.getBytes(UTF_8));
+
+    parseCommand(stdIn, RLP_SUBCOMMAND_NAME, RLP_DECODE_SUBCOMMAND_NAME, "--to", file.getPath());
+
+    final String expectedValidatorString =
+        "[0xbe068f726a13c8d46c44be6ce9d275600e1735a4, 0x5ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193]";
+
+    assertThat(contentOf(file)).contains(expectedValidatorString);
+
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+  }
+
+  @Test
+  public void decodeWithInputFilePathMustReadFromThisFile(final @TempDir Path dir)
+      throws Exception {
+    final Path tempJsonFile = Files.createTempFile(dir, "input", "json");
+    try (final BufferedWriter fileWriter = Files.newBufferedWriter(tempJsonFile, UTF_8)) {
+
+      fileWriter.write(
+          "0xf853a00000000000000000000000000000000000000000000000000000000000000000ea94be068f726a13c8d46c44be6ce9d275600e1735a4945ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193808400000000c0");
+
+      fileWriter.flush();
+
+      parseCommand(
+          RLP_SUBCOMMAND_NAME,
+          RLP_DECODE_SUBCOMMAND_NAME,
+          "--from",
+          tempJsonFile.toFile().getAbsolutePath());
+
+      final String expectedValidatorString =
+          "[0xbe068f726a13c8d46c44be6ce9d275600e1735a4, 0x5ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193]";
+
+      assertThat(commandOutput.toString(UTF_8)).contains(expectedValidatorString);
+      assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+    }
+  }
+
+  @Test
+  public void decodeWithInputFilePathToOutputFile(final @TempDir Path dir) throws Exception {
+    final Path tempInputFile = Files.createTempFile(dir, "input", "json");
+    final File tempOutputFile = File.createTempFile("ibftValidators", "rlp");
+    try (final BufferedWriter fileWriter = Files.newBufferedWriter(tempInputFile, UTF_8)) {
+
+      fileWriter.write(
+          "0xf853a00000000000000000000000000000000000000000000000000000000000000000ea94be068f726a13c8d46c44be6ce9d275600e1735a4945ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193808400000000c0");
+
+      fileWriter.flush();
+
+      parseCommand(
+          RLP_SUBCOMMAND_NAME,
+          RLP_DECODE_SUBCOMMAND_NAME,
+          "--from",
+          tempInputFile.toFile().getAbsolutePath(),
+          "--to",
+          tempOutputFile.getPath());
+
+      final String expectedValidatorString =
+          "[0xbe068f726a13c8d46c44be6ce9d275600e1735a4, 0x5ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193]";
+
+      assertThat(contentOf(tempOutputFile)).contains(expectedValidatorString);
+      assertThat(commandOutput.toString(UTF_8)).isEmpty();
+      assertThat(commandErrorOutput.toString(UTF_8)).isEmpty();
+    }
+  }
+
+  @Test
+  public void decodeWithEmptyStdInputMustRaiseAnError() throws Exception {
+
+    // set empty stdin
+    final String jsonInput = "";
+    final ByteArrayInputStream stdIn = new ByteArrayInputStream(jsonInput.getBytes(UTF_8));
+
+    parseCommand(stdIn, RLP_SUBCOMMAND_NAME, RLP_DECODE_SUBCOMMAND_NAME);
+
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).startsWith("Unable to read input data.");
+  }
+
+  @Test
+  public void decodeWithInputFilePathMustThrowErrorFileNotExist(final @TempDir Path dir)
+      throws Exception {
+
+    final String nonExistingFileName = "/incorrectPath/wrongFile.json";
+
+    parseCommand(RLP_SUBCOMMAND_NAME, RLP_DECODE_SUBCOMMAND_NAME, "--from", nonExistingFileName);
+
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8)).contains("Unable to read input file");
+  }
+
+  @Test
+  public void decodeWithEmptyInputMustRaiseAnError(final @TempDir Path dir) throws Exception {
+    final Path emptyFile = Files.createTempFile(dir, "empty", "json");
+    parseCommand(
+        RLP_SUBCOMMAND_NAME,
+        RLP_DECODE_SUBCOMMAND_NAME,
+        "--from",
+        emptyFile.toFile().getAbsolutePath());
+
+    assertThat(commandOutput.toString(UTF_8)).isEmpty();
+    assertThat(commandErrorOutput.toString(UTF_8))
+        .startsWith("An error occurred while trying to read the input data.");
+  }
+
   @AfterEach
   public void restoreStdin() {
     System.setIn(System.in);