RLP encode subcommand (PegaSysEng#944)

Add RLP encoding subcommand for at least ibftExtraData to be inserted in genesis file.

There's only one encodable type for the moment, however the `--type` option is already there with a default value on this type. We'll add more possible types later if needed and the current type will remain the default one.

The file output is optional and it writes to standard output by default, same for
standard input or a file.

Tests and doc change.

docs/Reference/Pantheon-CLI-Syntax.md

@@ -1033,4 +1033,76 @@ $ pantheon password hash --password=<my-password>
 
 ```bash tab="Example"
 $ pantheon password hash --password=myPassword123
-```
+```
+
+### rlp
+
+This command provides RLP related actions.
+
+#### encode
+
+This command encodes a typed JSON value from a file or from the standard input into an RLP hexadecimal string.
+
+```bash tab="Syntax"
+$ pantheon rlp encode [--from=<FILE>] [--to=<FILE>] [--type=<type>]
+```
+
+```bash tab="Example using files"
+$ pantheon rlp encode --from=ibft_extra_data.json --to=extra_data_for_ibft_genesis.txt --type=IBFT_EXTRA_DATA
+```
+
+```bash tab="Example using standard input/output and default type"
+$ cat extra_data.json | pantheon rlp encode > rlp.txt
+```
+
+##### Available types for encoding
+
+For the moment, only IBFT extra data type of RLP data is supported.
+This data is used to build the IBFT 2.0 genesis file.
+
+???+ summary "IBFT_EXTRA_DATA"
+    To generate the IBFT_EXTRA_DATA typed RLP string you need a JSON input containing an array with 
+    all the validator addresses strings that you want to insert in your genesis.
+
+    The JSON content is an object with a validator property that's an array of validator addresse strings.
+
+    ??? tip "JSON Schema for IBFT_EXTRA_DATA"
+        The following JSON Schema can be used to validate that your JSON data is well formed.
+        
+        Among many tools you can use some online validator tool like https://www.jsonschemavalidator.net/
+        to validate your JSON content.
+        
+        ```json
+        {
+          "$schema": "http://json-schema.org/draft-07/schema#",
+          "$id": "http://tech.pegasys.pantheon/cli_rlp_ibft_extra_data.json",
+          "type": "array",
+          "definitions": {},
+          "title": "IBFT extra data",
+          "description":"JSON format used as input to generate an IBFT extra data RLP string",
+          "items": {
+            "$id": "#/address",
+            "type": "string",
+            "title": "Validator address",
+            "description":"The validator node address",
+            "default": "",
+            "examples": [
+              "be068f726a13c8d46c44be6ce9d275600e1735a4",
+              "5ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193"
+            ],
+            "pattern":"^([0-9a-f]{40})$"
+          }
+        }
+        ``` 
+        
+    !!!example "Example IBFT_EXTRA_DATA encoding"
+        ```json tab="JSON input"
+        [
+          "be068f726a13c8d46c44be6ce9d275600e1735a4",
+          "5ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193"
+        ]
+        ```
+        
+        ``` tab="RLP output"
+        0xf853a00000000000000000000000000000000000000000000000000000000000000000ea94be068f726a13c8d46c44be6ce9d275600e1735a4945ff6f4b66a46a2b2310a6f3a93aaddc0d9a1c193808400000000c0
+        ```

pantheon/src/main/java/tech/pegasys/pantheon/Pantheon.java

@@ -39,6 +39,7 @@ public static void main(final String... args) {
     pantheonCommand.parse(
         new RunLast().andExit(SUCCESS_EXIT_CODE),
         defaultExceptionHandler().andExit(ERROR_EXIT_CODE),
+        System.in,
         args);
   }
 }

pantheon/src/main/java/tech/pegasys/pantheon/cli/DefaultCommandValues.java

@@ -26,7 +26,7 @@
 
 import picocli.CommandLine;
 
-interface DefaultCommandValues {
+public interface DefaultCommandValues {
   String CONFIG_FILE_OPTION_NAME = "--config-file";
 
   String MANDATORY_PATH_FORMAT_HELP = "<PATH>";

pantheon/src/main/java/tech/pegasys/pantheon/cli/PantheonCommand.java

@@ -31,6 +31,7 @@
 import tech.pegasys.pantheon.cli.custom.EnodeToURIPropertyConverter;
 import tech.pegasys.pantheon.cli.custom.JsonRPCWhitelistHostsProperty;
 import tech.pegasys.pantheon.cli.custom.RpcAuthFileValidator;
+import tech.pegasys.pantheon.cli.rlp.RLPSubCommand;
 import tech.pegasys.pantheon.config.GenesisConfigFile;
 import tech.pegasys.pantheon.consensus.clique.jsonrpc.CliqueRpcApis;
 import tech.pegasys.pantheon.consensus.ibft.jsonrpc.IbftRpcApis;
@@ -58,6 +59,7 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
 import java.net.InetAddress;
 import java.net.URI;
 import java.nio.file.Path;
@@ -474,6 +476,7 @@ public PantheonCommand(
   public void parse(
       final AbstractParseResultHandler<List<Object>> resultHandler,
       final DefaultExceptionHandler<List<Object>> exceptionHandler,
+      final InputStream in,
       final String... args) {
 
     commandLine = new CommandLine(this);
@@ -492,6 +495,8 @@ public void parse(
         PublicKeySubCommand.COMMAND_NAME, new PublicKeySubCommand(resultHandler.out()));
     commandLine.addSubcommand(
         PasswordSubCommand.COMMAND_NAME, new PasswordSubCommand(resultHandler.out()));
+    commandLine.addSubcommand(
+        RLPSubCommand.COMMAND_NAME, new RLPSubCommand(resultHandler.out(), in));
 
     commandLine.registerConverter(Address.class, Address::fromHexString);
     commandLine.registerConverter(BytesValue.class, BytesValue::fromHexString);

pantheon/src/main/java/tech/pegasys/pantheon/cli/rlp/IbftExtraDataCLIAdapter.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.cli.rlp;
+
+import tech.pegasys.pantheon.consensus.ibft.IbftExtraData;
+import tech.pegasys.pantheon.ethereum.core.Address;
+import tech.pegasys.pantheon.util.bytes.BytesValue;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * Adapter to convert a typed JSON to an IbftExtraData object This adapter handles the JSON to RLP
+ * encoding
+ */
+public class IbftExtraDataCLIAdapter implements JSONToRLP {
+
+  @Override
+  public BytesValue encode(final String json) throws IOException {
+    ObjectMapper mapper = new ObjectMapper();
+    TypeReference<Collection<String>> typeRef = new TypeReference<Collection<String>>() {};
+    Collection<String> validatorAddresse = mapper.readValue(json, typeRef);
+
+    Collection<Address> addresses =
+        validatorAddresse.stream().map(Address::fromHexString).collect(Collectors.toList());
+
+    return new IbftExtraData(
+            BytesValue.wrap(new byte[32]), Collections.emptyList(), Optional.empty(), 0, addresses)
+        .encode();
+  }
+}

pantheon/src/main/java/tech/pegasys/pantheon/cli/rlp/JSONToRLP.java

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2019 ConsenSys AG.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+package tech.pegasys.pantheon.cli.rlp;
+
+import tech.pegasys.pantheon.util.bytes.BytesValue;
+
+import java.io.IOException;
+
+/** Behaviour of objects that can be encoded from JSON to RLP */
+interface JSONToRLP {
+
+  /**
+   * Encodes the object into an RLP value.
+   *
+   * @return the RLP encoded object.
+   */
+  BytesValue encode(String json) throws IOException;
+}