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RLP Refactor
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- decode - index check
- decodeInt improvement
- removing unnecessary methods
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@asoto-iov @Vovchyk
asoto-iov authored and Vovchyk committed Jul 3, 2024
1 parent 5535aa5 commit 8d8719e
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Showing 2 changed files with 58 additions and 131 deletions.
92 changes: 33 additions & 59 deletions rskj-core/src/main/java/org/ethereum/util/RLP.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -155,24 +155,33 @@ private static byte decodeOneByteItem(byte[] data, int index) {
}

public static int decodeInt(byte[] data, int index) {
int value = 0;
// NOTE: there are two ways zero can be encoded - 0x00 and OFFSET_SHORT_ITEM

if ((data[index] & 0xFF) < OFFSET_SHORT_ITEM) {
if (index < 0 || index >= data.length) {
throw new RLPException("Index out of bounds");
}

int firstByte = data[index] & 0xFF;

if (firstByte < OFFSET_SHORT_ITEM) {
return data[index];
} else if ((data[index] & 0xFF) >= OFFSET_SHORT_ITEM
&& (data[index] & 0xFF) < OFFSET_LONG_ITEM) {
}

if (firstByte < OFFSET_LONG_ITEM) {
int value = 0;

byte length = (byte) (data[index] - OFFSET_SHORT_ITEM);
if(length >= (data.length - index)) {
throw new RLPException("RLP wrong encoding");
}
byte pow = (byte) (length - 1);
for (int i = 1; i <= length; ++i) {
value += (data[index + i] & 0xFF) << (8 * pow);
pow--;
}
} else {
throw new RuntimeException("wrong decode attempt");
return value;
}
return value;
throw new RLPException("wrong decode attempt");
}

public static BigInteger decodeBigInteger(byte[] data, int index) {
Expand All @@ -191,46 +200,6 @@ public static BigInteger decodeBigInteger(byte[] data, int index) {
return BigIntegers.fromUnsignedByteArray(bytes);
}

public static byte[] decodeIP4Bytes(byte[] data, int index) {

int offset = 1;

final byte[] result = new byte[4];
for (int i = 0; i < 4; i++) {
result[i] = decodeOneByteItem(data, index + offset);
if ((data[index + offset] & 0xFF) > OFFSET_SHORT_ITEM) {
offset += 2;
} else {
offset += 1;
}
}

// return IP address
return result;
}

public static int getFirstListElement(byte[] payload, int pos) {

if (pos >= payload.length) {
return -1;
}

if ((payload[pos] & 0xFF) >= OFFSET_LONG_LIST) {
byte lengthOfLength = (byte) (payload[pos] - OFFSET_LONG_LIST);
return pos + lengthOfLength + 1;
}
if ((payload[pos] & 0xFF) >= OFFSET_SHORT_LIST
&& (payload[pos] & 0xFF) < OFFSET_LONG_LIST) {
return pos + 1;
}
if ((payload[pos] & 0xFF) >= OFFSET_LONG_ITEM
&& (payload[pos] & 0xFF) < OFFSET_SHORT_LIST) {
byte lengthOfLength = (byte) (payload[pos] - OFFSET_LONG_ITEM);
return pos + lengthOfLength + 1;
}
return -1;
}

public static int getNextElementIndex(byte[] payload, int pos) {

if (pos >= payload.length) {
Expand Down Expand Up @@ -426,25 +395,22 @@ private static Pair<RLPElement, Integer> decodeElement(byte[] msgData, int posit
if (b0 <= 192 + TINY_SIZE) {
length = b0 - 192 + 1;
offset = 1;
}
else {
} else {
int nbytes = b0 - 247;
length = 1 + nbytes + bytesToLength(msgData, position + 1, nbytes);
offset = 1 + nbytes;
length = safeAdd(offset, bytesToLength(msgData, position + 1, nbytes));
}

if (Long.compareUnsigned(length, Integer.MAX_VALUE) > 0) {
throw new RLPException("The current implementation doesn't support lengths longer than Integer.MAX_VALUE because that is the largest number of elements an array can have");
}
int endingIndex = safeAdd(length, position);

if (position + length > msgData.length) {
if (endingIndex > msgData.length) {
throw new RLPException("The RLP byte array doesn't have enough space to hold an element with the specified length");
}

byte[] bytes = Arrays.copyOfRange(msgData, position, position + length);
byte[] bytes = Arrays.copyOfRange(msgData, position, endingIndex);
RLPList list = new RLPList(bytes, offset);

return Pair.of(list, position + length);
return Pair.of(list, endingIndex);
}

if (b0 == EMPTY_MARK) {
Expand All @@ -463,8 +429,7 @@ private static Pair<RLPElement, Integer> decodeElement(byte[] msgData, int posit
if (b0 > (EMPTY_MARK + TINY_SIZE)) {
offset = b0 - (EMPTY_MARK + TINY_SIZE) + 1;
length = bytesToLength(msgData, position + 1, offset - 1);
}
else {
} else {
length = b0 & 0x7f;
offset = 1;
}
Expand All @@ -473,7 +438,8 @@ private static Pair<RLPElement, Integer> decodeElement(byte[] msgData, int posit
throw new RLPException("The current implementation doesn't support lengths longer than Integer.MAX_VALUE because that is the largest number of elements an array can have");
}

if (position + offset + length < 0 || position + offset + length > msgData.length) {
int endingIndex = position + offset + length;
if ( endingIndex < 0 || endingIndex > msgData.length) {
throw new RLPException("The RLP byte array doesn't have enough space to hold an element with the specified length");
}

Expand All @@ -484,6 +450,14 @@ private static Pair<RLPElement, Integer> decodeElement(byte[] msgData, int posit
return Pair.of(new RLPItem(decoded), position + offset + length);
}

private static int safeAdd(int a, int b) {
try{
return Math.addExact(a, b);
}catch (ArithmeticException ex){
throw new RLPException("The current implementation doesn't support lengths longer than Integer.MAX_VALUE because that is the largest number of elements an array can have");
}
}

private static int bytesToLength(byte[] bytes, int position, int size) {
if (position + size > bytes.length) {
throw new RLPException("The length of the RLP item length can't possibly fit the data byte array");
Expand Down
97 changes: 25 additions & 72 deletions rskj-core/src/test/java/org/ethereum/util/RLPTest.java
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,8 @@

package org.ethereum.util;

import co.rsk.util.RLPException;
import org.apache.commons.codec.binary.Base64;
import org.bouncycastle.util.BigIntegers;
import org.bouncycastle.util.encoders.Hex;
import org.ethereum.crypto.HashUtil;
Expand All @@ -34,7 +36,6 @@
import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.math.BigInteger;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.*;

Expand All @@ -47,23 +48,6 @@
@SuppressWarnings("squid:S2699")
class RLPTest {

@Test
void test1() throws UnknownHostException {

String peersPacket = "F8 4E 11 F8 4B C5 36 81 " +
"CC 0A 29 82 76 5F B8 40 D8 D6 0C 25 80 FA 79 5C " +
"FC 03 13 EF DE BA 86 9D 21 94 E7 9E 7C B2 B5 22 " +
"F7 82 FF A0 39 2C BB AB 8D 1B AC 30 12 08 B1 37 " +
"E0 DE 49 98 33 4F 3B CF 73 FA 11 7E F2 13 F8 74 " +
"17 08 9F EA F8 4C 21 B0";

byte[] payload = Hex.decode(peersPacket);

byte[] ip = decodeIP4Bytes(payload, 5);

assertEquals(InetAddress.getByAddress(ip).toString(), ("/54.204.10.41"));
}

@Test
void test2() throws UnknownHostException {

Expand All @@ -80,60 +64,6 @@ void test2() throws UnknownHostException {
assertEquals(30303, oneInt);
}

@Test
void test3() throws UnknownHostException {

String peersPacket = "F8 9A 11 F8 4B C5 36 81 " +
"CC 0A 29 82 76 5F B8 40 D8 D6 0C 25 80 FA 79 5C " +
"FC 03 13 EF DE BA 86 9D 21 94 E7 9E 7C B2 B5 22 " +
"F7 82 FF A0 39 2C BB AB 8D 1B AC 30 12 08 B1 37 " +
"E0 DE 49 98 33 4F 3B CF 73 FA 11 7E F2 13 F8 74 " +
"17 08 9F EA F8 4C 21 B0 F8 4A C4 36 02 0A 29 " +
"82 76 5F B8 40 D8 D6 0C 25 80 FA 79 5C FC 03 13 " +
"EF DE BA 86 9D 21 94 E7 9E 7C B2 B5 22 F7 82 FF " +
"A0 39 2C BB AB 8D 1B AC 30 12 08 B1 37 E0 DE 49 " +
"98 33 4F 3B CF 73 FA 11 7E F2 13 F8 74 17 08 9F " +
"EA F8 4C 21 B0 ";

byte[] payload = Hex.decode(peersPacket);

int nextIndex = 5;
byte[] ip = decodeIP4Bytes(payload, nextIndex);
assertEquals("/54.204.10.41", InetAddress.getByAddress(ip).toString());

nextIndex = getNextElementIndex(payload, nextIndex);
int port = decodeInt(payload, nextIndex);
assertEquals(30303, port);

nextIndex = getNextElementIndex(payload, nextIndex);
BigInteger peerId = decodeBigInteger(payload, nextIndex);

BigInteger expectedPeerId =
new BigInteger("11356629247358725515654715129711890958861491612873043044752814241820167155109073064559464053586837011802513611263556758124445676272172838679152022396871088");
assertEquals(expectedPeerId, peerId);

nextIndex = getNextElementIndex(payload, nextIndex);
nextIndex = getFirstListElement(payload, nextIndex);
ip = decodeIP4Bytes(payload, nextIndex);
assertEquals("/54.2.10.41", InetAddress.getByAddress(ip).toString());

nextIndex = getNextElementIndex(payload, nextIndex);
port = decodeInt(payload, nextIndex);
assertEquals(30303, port);

nextIndex = getNextElementIndex(payload, nextIndex);
peerId = decodeBigInteger(payload, nextIndex);

expectedPeerId =
new BigInteger("11356629247358725515654715129711890958861491612873043044752814241820167155109073064559464053586837011802513611263556758124445676272172838679152022396871088");

assertEquals(expectedPeerId, peerId);

nextIndex = getNextElementIndex(payload, nextIndex);
nextIndex = getFirstListElement(payload, nextIndex);
assertEquals(-1, nextIndex);
}

@Test
/** encode byte */
void test4() {
Expand Down Expand Up @@ -1118,4 +1048,27 @@ void shortStringRightBoundTest() {
String res = new String(decode2(rlpEncoded).get(0).getRLPData());
assertEquals(testString, res);
}

@Test
void testDecode2_outOfMem() {
byte[] payload = Base64.decodeBase64("BQACAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA/QH4f///9wAAAAAAAAAABSQGYA==");
assertThrows(RLPException.class, () -> RLP.decode2(payload));
}

@Test
void testDecode2() {
byte[] payload = Base64.decodeBase64("ADU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTU1NTX//8DLAH///8s=");
assertThrows(RLPException.class, () -> RLP.decode2(payload));
}
@Test
void testDecodeInt() {
byte[] payload = Base64.decodeBase64("kQo=");
assertThrows(RLPException.class, () -> RLP.decodeInt(payload, 0));
}

@Test
void testIncorrectDecodeInt(){
byte[] payload = {(byte) 0x84, (byte) 0x00, (byte) 0x00, (byte) 0x84, (byte) 0x00, (byte) 0x0f, (byte) 0xab};
assertThrows(RLPException.class, () -> RLP.decodeInt(payload, 3));
}
}

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