ethers.js/docs/v5/api/utils/hashing/README.md
2020-11-22 23:07:13 -05:00

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-----
Documentation: [html](https://docs.ethers.io/)
-----
Hashing Algorithms
==================
Cryptographic Hash Functions
----------------------------
#### *ethers* . *utils* . **id**( text ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
The Ethereum Identity function computes the [KECCAK256](https://en.wikipedia.org/wiki/SHA-3) hash of the *text* bytes.
#### *ethers* . *utils* . **keccak256**( aBytesLike ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Returns the [KECCAK256](https://en.wikipedia.org/wiki/SHA-3) digest *aBytesLike*.
#### *ethers* . *utils* . **ripemd160**( aBytesLike ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 20 > >*
Returns the [RIPEMD-160](https://en.m.wikipedia.org/wiki/RIPEMD) digest of *aBytesLike*.
#### *ethers* . *utils* . **sha256**( aBytesLike ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Returns the [SHA2-256](https://en.wikipedia.org/wiki/SHA-2) digest of *aBytesLike*.
#### *ethers* . *utils* . **sha512**( aBytesLike ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 64 > >*
Returns the [SHA2-512](https://en.wikipedia.org/wiki/SHA-2) digest of *aBytesLike*.
```javascript
utils.keccak256([ 0x12, 0x34 ])
// '0x56570de287d73cd1cb6092bb8fdee6173974955fdef345ae579ee9f475ea7432'
utils.keccak256("0x")
// '0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470'
utils.keccak256("0x1234")
// '0x56570de287d73cd1cb6092bb8fdee6173974955fdef345ae579ee9f475ea7432'
// The value MUST be data, such as:
// - an Array of numbers
// - a data hex string (e.g. "0x1234")
// - a Uint8Array
// Do NOT use UTF-8 strings that are not a DataHexstring
utils.keccak256("hello world")
// Error: invalid arrayify value (argument="value", value="hello world", code=INVALID_ARGUMENT, version=bytes/5.0.6)
// If needed, convert strings to bytes first:
utils.keccak256(utils.toUtf8Bytes("hello world"))
// '0x47173285a8d7341e5e972fc677286384f802f8ef42a5ec5f03bbfa254cb01fad'
// Or equivalently use the identity function:
utils.id("hello world")
// '0x47173285a8d7341e5e972fc677286384f802f8ef42a5ec5f03bbfa254cb01fad'
// Keep in mind that the string "0x1234" represents TWO
// bytes (i.e. [ 0x12, 0x34 ]. If you wish to compute the
// hash of the 6 characters "0x1234", convert it to UTF-8
// bytes first using utils.toUtf8Bytes.
// Consider the following examples:
// Hash of TWO (2) bytes:
utils.keccak256("0x1234")
// '0x56570de287d73cd1cb6092bb8fdee6173974955fdef345ae579ee9f475ea7432'
// Hash of TWO (2) bytes: (same result)
utils.keccak256([ 0x12, 0x34 ])
// '0x56570de287d73cd1cb6092bb8fdee6173974955fdef345ae579ee9f475ea7432'
const bytes = utils.toUtf8Bytes("0x1234")
// Uint8Array [ 48, 120, 49, 50, 51, 52 ]
// Hash of SIX (6) characters (different than above)
utils.keccak256(bytes)
// '0x1ac7d1b81b7ba1025b36ccb86723da6ee5a87259f1c2fd5abe69d3200b512ec8'
// Hash of SIX (6) characters (same result)
utils.id("0x1234")
// '0x1ac7d1b81b7ba1025b36ccb86723da6ee5a87259f1c2fd5abe69d3200b512ec8'
```
```javascript
utils.ripemd160("0x")
// '0x9c1185a5c5e9fc54612808977ee8f548b2258d31'
utils.ripemd160("0x1234")
// '0xc39867e393cb061b837240862d9ad318c176a96d'
```
```javascript
utils.sha256("0x")
// '0xe3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855'
utils.sha256("0x1234")
// '0x3a103a4e5729ad68c02a678ae39accfbc0ae208096437401b7ceab63cca0622f'
utils.sha512("0x")
// '0xcf83e1357eefb8bdf1542850d66d8007d620e4050b5715dc83f4a921d36ce9ce47d0d13c5d85f2b0ff8318d2877eec2f63b931bd47417a81a538327af927da3e'
utils.sha512("0x1234")
// '0x4c54886c9821195522d88ff4705c3e0c686b921054421e6ea598739c29c26e1ee75419aaceec94dd2e3c0dbb82ecf895c9f61215f375de6d800d9b99d3d4b816'
```
HMAC
----
#### *ethers* . *utils* . **computeHmac**( algorithm , key , data ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString) >*
Returns the [HMAC](https://en.wikipedia.org/wiki/HMAC) of *data* with *key* using the [Algorithm](/v5/api/utils/hashing/#utils--hmac-supported-algorithm) *algorithm*.
### HMAC Supported Algorithms
#### *ethers* . *utils* . *SupportedAlgorithm* . **sha256** => *string*
Use the [SHA2-256](https://en.wikipedia.org/wiki/SHA-2) hash algorithm.
#### *ethers* . *utils* . *SupportedAlgorithm* . **sha512** => *string*
Use the [SHA2-512](https://en.wikipedia.org/wiki/SHA-2) hash algorithm.
```javascript
const key = "0x0102"
const data = "0x1234"
utils.computeHmac("sha256", key, data)
// '0x7553df81c628815cf569696cad13a37c606c5058df13d9dff4fee2cf5e9b5779'
```
Hashing Helpers
---------------
#### *ethers* . *utils* . **hashMessage**( message ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Computes the [EIP-191](https://eips.ethereum.org/EIPS/eip-191) personal message digest of *message*. Personal messages are converted to UTF-8 bytes and prefixed with `\x19Ethereum Signed Message:` and the length of *message*.
```javascript
// Hashing a string message
utils.hashMessage("Hello World")
// '0xa1de988600a42c4b4ab089b619297c17d53cffae5d5120d82d8a92d0bb3b78f2'
// Hashing binary data (also "Hello World", but as bytes)
utils.hashMessage( [ 72, 101, 108, 108, 111, 32, 87, 111, 114, 108, 100 ])
// '0xa1de988600a42c4b4ab089b619297c17d53cffae5d5120d82d8a92d0bb3b78f2'
// NOTE: It is important to understand how strings and binary
// data is handled differently. A string is ALWAYS processed
// as the bytes of the string, so a hexstring MUST be
// converted to an ArrayLike object first.
// Hashing a hex string is the same as hashing a STRING
// Note: this is the hash of the 4 characters [ '0', 'x', '4', '2' ]
utils.hashMessage("0x42")
// '0xf0d544d6e4a96e1c08adc3efabe2fcb9ec5e28db1ad6c33ace880ba354ab0fce'
// Hashing the binary data
// Note: this is the hash of the 1 byte [ 0x42 ]
utils.hashMessage([ 0x42 ])
// '0xd18c12b87124f9ceb7e1d3a5d06a5ac92ecab15931417e8d1558d9a263f99d63'
// Hashing the binary data
// Note: similarly, this is the hash of the 1 byte [ 0x42 ]
utils.hashMessage(utils.arrayify("0x42"))
// '0xd18c12b87124f9ceb7e1d3a5d06a5ac92ecab15931417e8d1558d9a263f99d63'
```
#### *ethers* . *utils* . **namehash**( name ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Returns the [ENS Namehash](https://docs.ens.domains/contract-api-reference/name-processing#hashing-names) of *name*.
```javascript
utils.namehash("")
// '0x0000000000000000000000000000000000000000000000000000000000000000'
utils.namehash("eth")
// '0x93cdeb708b7545dc668eb9280176169d1c33cfd8ed6f04690a0bcc88a93fc4ae'
utils.namehash("ricmoo.firefly.eth")
// '0x0bcad17ecf260d6506c6b97768bdc2acfb6694445d27ffd3f9c1cfbee4a9bd6d'
utils.namehash("ricmoo.xyz")
// '0x7d56aa46358ba2f8b77d8e05bcabdd2358370dcf34e87810f8cea77ecb3fc57d'
```
### Typed Data Encoder
#### Experimental Feature (this exported class name will change)
This is still an experimental feature. If using it, please specify the **exact** version of ethers you are using (e.g. spcify `"5.0.18"`, **not** `"^5.0.18"`) as the exported class name will be renamed from `_TypedDataEncoder` to `TypedDataEncoder` once it has been used in the field a bit.
#### *ethers* . *utils* . *_TypedDataEncoder* . **from**( types ) => *[TypedDataEncoder]*
Creates a new **TypedDataEncoder** for *types*. This object is a fairly low-level object that most developers should not require using instances directly.
Most developers will find the static class methods below the most useful.
#### *TypedDataEncoder* . **encode**( domain , types , values ) => *string*
Encodes the Returns the hashed [EIP-712](https://eips.ethereum.org/EIPS/eip-712) domain.
#### *TypedDataEncoder* . **getPayload**( domain , types , value ) => *any*
Returns the standard payload used by various JSON-RPC `eth_signTypedData*` calls.
All domain values and entries in value are normalized and the types are verified.
#### *TypedDataEncoder* . **getPrimaryType**( types ) => *string*
Constructs a directed acyclic graph of the types and returns the root type, which can be used as the **primaryType** for [EIP-712](https://eips.ethereum.org/EIPS/eip-712) payloads.
#### *TypedDataEncoder* . **hash**( domain , types , values ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Returns the computed [EIP-712](https://eips.ethereum.org/EIPS/eip-712) hash.
#### *TypedDataEncoder* . **hashDomain**( domain ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Returns the hashed [EIP-712](https://eips.ethereum.org/EIPS/eip-712) domain.
#### *TypedDataEncoder* . **resolveNames**( domain , types , value , resolveName ) => *Promise< any >*
Returns a copy of value, where any leaf value with a type of `address` will have been recursively replacedwith the value of calling *resolveName* with that value.
```javascript
const domain = {
name: 'Ether Mail',
version: '1',
chainId: 1,
verifyingContract: '0xCcCCccccCCCCcCCCCCCcCcCccCcCCCcCcccccccC'
}
// The named list of all type definitions
const types = {
Person: [
{ name: 'name', type: 'string' },
{ name: 'wallet', type: 'address' }
],
Mail: [
{ name: 'from', type: 'Person' },
{ name: 'to', type: 'Person' },
{ name: 'contents', type: 'string' }
]
}
// The data to sign
const value = {
from: {
name: 'Cow',
wallet: '0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826'
},
to: {
name: 'Bob',
wallet: '0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB'
},
contents: 'Hello, Bob!'
}
TypedDataEncoder.encode(domain, types, value)
// '0x1901f2cee375fa42b42143804025fc449deafd50cc031ca257e0b194a650a912090fc52c0ee5d84264471806290a3f2c4cecfc5490626bf912d01f240d7a274b371e'
TypedDataEncoder.getPayload(domain, types, value)
// {
// domain: {
// chainId: '1',
// name: 'Ether Mail',
// verifyingContract: '0xcccccccccccccccccccccccccccccccccccccccc',
// version: '1'
// },
// message: {
// contents: 'Hello, Bob!',
// from: {
// name: 'Cow',
// wallet: '0xcd2a3d9f938e13cd947ec05abc7fe734df8dd826'
// },
// to: {
// name: 'Bob',
// wallet: '0xbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'
// }
// },
// primaryType: 'Mail',
// types: {
// Mail: [
// {
// name: 'from',
// type: 'Person'
// },
// {
// name: 'to',
// type: 'Person'
// },
// {
// name: 'contents',
// type: 'string'
// }
// ],
// Person: [
// {
// name: 'name',
// type: 'string'
// },
// {
// name: 'wallet',
// type: 'address'
// }
// ]
// }
// }
TypedDataEncoder.getPrimaryType(types)
// 'Mail'
TypedDataEncoder.hash(domain, types, value)
// '0xbe609aee343fb3c4b28e1df9e632fca64fcfaede20f02e86244efddf30957bd2'
TypedDataEncoder.hashDomain(domain)
// '0xf2cee375fa42b42143804025fc449deafd50cc031ca257e0b194a650a912090f'
```
Solidity Hashing Algorithms
---------------------------
#### *ethers* . *utils* . **solidityPack**( types , values ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString) >*
Returns the non-standard encoded *values* packed according to their respective type in *types*.
#### *ethers* . *utils* . **solidityKeccak256**( types , values ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Returns the [KECCAK256](https://en.wikipedia.org/wiki/SHA-3) of the non-standard encoded *values* packed according to their respective type in *types*.
#### *ethers* . *utils* . **soliditySha256**( types , values ) => *string< [DataHexString](/v5/api/utils/bytes/#DataHexString)< 32 > >*
Returns the [SHA2-256](https://en.wikipedia.org/wiki/SHA-2) of the non-standard encoded *values* packed according to their respective type in *types*.
```javascript
utils.solidityPack([ "int16", "uint48" ], [ -1, 12 ])
// '0xffff00000000000c'
utils.solidityPack([ "string", "uint8" ], [ "Hello", 3 ])
// '0x48656c6c6f03'
utils.solidityKeccak256([ "int16", "uint48" ], [ -1, 12 ])
// '0x81da7abb5c9c7515f57dab2fc946f01217ab52f3bd8958bc36bd55894451a93c'
utils.soliditySha256([ "int16", "uint48" ], [ -1, 12 ])
// '0xa5580fb602f6e2ba9c588011dc4e6c2335e0f5d970dc45869db8f217efc6911a'
// As a short example of the non-distinguished nature of
// Solidity tight-packing (which is why it is inappropriate
// for many things from a security point of view), consider
// the following examples are all equal, despite representing
// very different values and layouts.
utils.solidityPack([ "string", "string" ], [ "hello", "world01" ])
// '0x68656c6c6f776f726c643031'
utils.solidityPack([ "string", "string" ], [ "helloworld", "01" ])
// '0x68656c6c6f776f726c643031'
utils.solidityPack([ "string", "string", "uint16" ], [ "hell", "oworld", 0x3031 ])
// '0x68656c6c6f776f726c643031'
utils.solidityPack([ "uint96" ], [ "32309054545061485574011236401" ])
// '0x68656c6c6f776f726c643031'
```