php-rlp

A high-performance PHP extension for RLP (Recursive Length Prefix) encoding and decoding, compatible with Ethereum’s transaction and contract formats. Built natively in C for maximum speed, fully interoperable with KornRunner’s RLP implementation and EVM tooling.

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Functions

Function	Purpose
rlp_encode()	Encode a string, integer, or array to RLP
rlp_decode()	Decode an RLP string into PHP types

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EVM Compatibility

This extension matches Ethereum’s canonical RLP format used for:

• Transactions (nonce, gasPrice, to, value, data, v, r, s)
• Smart contract deployments and calls
• EIP-155 chain-ID encoding
• Event logs and receipts

The encoder supports:

• Raw binary and text strings
• Hex strings prefixed with 0x (converted to binary before encoding)
• Integers (int, long)
• Arrays (any nested structure)

The decoder returns:

• PHP string for raw values
• PHP array for RLP lists

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Installation

Prerequisites

sudo apt install php-dev autoconf make gcc

Build & Install

git clone https://github.com/RandomCoderTinker/php-rlp.git
cd php-rlp
phpize
./configure
make
sudo make install

Enable in php.ini:

extension=php_rlp.so

Restart PHP-FPM or your web server.

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Usage

<?php

// RLP encode/decode strings
echo bin2hex(rlp_encode("Dog"));   // 83446f67
echo rlp_decode(hex2bin("83446f67")); // Dog

// RLP encode an Ethereum transaction
$tx = [
    'nonce'    => '0x00',
    'gasPrice' => '0x09184e72a000',
    'gasLimit' => '0x2710',
    'to'       => '0x0000000000000000000000000000000000000000',
    'value'    => '0x00',
    'data'     => '',
    'v'        => '0x1b',
    'r'        => '0x00',
    's'        => '0x00'
];

$encoded = rlp_encode($tx);
echo bin2hex($encoded);

// Decode
$decoded = rlp_decode($encoded);
print_r($decoded);

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Output Format

Type	PHP Input	RLP Output (hex)
String	"Dog"	83446f67
Hex	"0xdeadbeef"	84deadbeef
Int	15	0f
Array	["cat", "dog"]	c88363617483646f67
Tx	Ethereum Tx array	Matches EVM / web3 compatible form

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Performance Benchmarks

Operation	C Extension	KornRunner (PHP)	Speedup
Encode	6.667 ms	88.314 ms	~13.2×
Decode	2.874 ms	73.849 ms	~25.7×

Benchmarked over 10,000 iterations on identical hardware.

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Real-world Use Cases

This extension is ideal for:

• Ethereum & L2 Transaction Builders
• EVM-compatible VM integration
• Smart contract encode/decode
• Custom chains and wallets
• High-performance RPC & Bridge Layers

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License

MIT © RandomCoderTinker

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Built with ❤️ using PHP 8.1+