What is content-hash?
The content-hash npm package is used to generate content hashes for various types of content. This can be useful for caching, versioning, and ensuring data integrity.
What are content-hash's main functionalities?
Generate Hash for a String
This feature allows you to generate a hash for a given string. The hash can be used to uniquely identify the content of the string.
const contentHash = require('content-hash');
const hash = contentHash('Hello, World!');
console.log(hash);
Generate Hash for a Buffer
This feature allows you to generate a hash for a Buffer object. This is useful for binary data or files.
const contentHash = require('content-hash');
const buffer = Buffer.from('Hello, World!');
const hash = contentHash(buffer);
console.log(hash);
Generate Hash for a File
This feature allows you to generate a hash for a file by reading its contents into a Buffer and then hashing it. This is useful for ensuring file integrity.
const fs = require('fs');
const contentHash = require('content-hash');
const filePath = 'path/to/your/file.txt';
const fileBuffer = fs.readFileSync(filePath);
const hash = contentHash(fileBuffer);
console.log(hash);
Other packages similar to content-hash
hasha
The hasha package is a versatile hashing library that supports multiple algorithms like MD5, SHA-1, and SHA-256. It is similar to content-hash but offers more flexibility in terms of hashing algorithms.
crypto
The crypto package is a built-in Node.js module that provides cryptographic functionality, including hashing. It is more low-level compared to content-hash but offers extensive features for cryptographic operations.
object-hash
The object-hash package is designed to hash JavaScript objects. It is similar to content-hash but specifically optimized for object hashing, making it useful for generating unique identifiers for complex data structures.
content-hash
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This is a simple package made for encoding and decoding content hashes as specified in the EIP 1577.
This package will be useful for every Ethereum developer wanting to interact with EIP 1577 compliant ENS resolvers.
Here you can find a live demo of this package.
🔠 Supported Codec
swarm-ns
ipfs-ns
ipns-ns
- Every other codec supported by multicodec will be encoded by default in
utf-8
.
You can see the full list of codec supported here
📥 Install
For browser only usage, installation is not required.
🛠 Usage
Import the module in order to use it :
- NodeJS :
const contentHash = require('content-hash')
- Browser :
<script type="text/javascript" src="https://unpkg.com/content-hash/dist/index.js"></script>
<script type="text/javascript" src="path/to/dist/index.js"></script>
To rebuild the browser version of the package run npm run build
into the root folder. Don't forget to also run npm run lint
and npm test
before building !
📕 API
All hex string inputs can be prefixed with 0x
, but it's not mandatory.
⚠️ All outputs are NOT prefixed with 0x
contentHash.decode( contentHash ) -> string
This function takes a content hash as a hex string and returns the decoded content as a string.
const encoded = 'e3010170122029f2d17be6139079dc48696d1f582a8530eb9805b561eda517e22a892c7e3f1f'
const content = contentHash.decode(encoded)
contentHash.fromIpfs( ipfsHash ) -> string
This function takes an IPFS address as a base58 encoded string and returns the encoded content hash as a hex string.
this function just call contentHash.encode()
under the hood
const ipfsHash = 'QmRAQB6YaCyidP37UdDnjFY5vQuiBrcqdyoW1CuDgwxkD4'
const contentH = contentHash.fromIpfs(ipfsHash)
contentHash.fromSwarm( swarmHash ) -> string
This function takes a Swarm address as a hex string and returns the encoded content hash as a hex string.
this function just call contentHash.encode()
under the hood
const swarmHash = 'd1de9994b4d039f6548d191eb26786769f580809256b4685ef316805265ea162'
const contentH = contentHash.fromSwarm(swarmHash)
contentHash.encode( codec, value) -> string
This function takes a supported codec as a string and a value as a string and returns coresponding content hash as a hex string.
const onion = 'zqktlwi4fecvo6ri'
contentHash.encode('onion', onion);
contentHash.getCodec( contentHash ) -> string
This function takes a content hash as a hex string and returns the codec as a hex string.
const encoded = 'e40101701b20d1de9994b4d039f6548d191eb26786769f580809256b4685ef316805265ea162'
const codec = contentHash.getCodec(encoded)
codec === 'ipfs-ns'
contentHash.helpers
This object contain the following helpers functions :
👨💻 Maintainer
🙌 Contributing
For any questions, discussions, bug report, or whatever I will be happy to answer through the issues or on my twitter 😁. PR (with tests) are also welcome !
📝 License
This project is licensed under the ISC License, you can find it here.
Note that the dependencies may have a different License