@trust/keyto
Version:
A utility for translating cryptographic keys between representations
114 lines (90 loc) • 2.38 kB
JavaScript
/**
* Dependencies
* @ignore
*/
const asn = require('asn1.js')
const base64url = require('base64url')
/**
* Converter
*
* @class Converter
*
* @description
* Utility class to convert between different data representations
*/
class Converter {
/**
* convert
*
* @description
* Convert between data types. Available data types: raw, uint8_array, hex, base64, base64url and (bn | bignum)
*
* @throws
* If fromType is not one of: raw, uint8_array, hex, base64, base64url or (bn | bignum)
*
* @throws
* If toType is not one of: raw, uint8_array, hex, base64, base64url or (bn | bignum)
*
* @param {(String|Array|Buffer|BigNumber)} data
* @param {String} fromType
* @param {String} toType
* @return {String|BigNumber}
*/
static convert(data, fromType, toType) {
if (!data) {
return undefined
}
if (fromType === toType) {
return data
}
let buffer
if (fromType === 'raw' || data instanceof Buffer) {
buffer = data
} else if (fromType === 'uint8_array' || Array.isArray(data)) {
buffer = Buffer.from(data)
} else if (fromType === 'hex') {
buffer = Buffer.from(data, 'hex')
} else if (fromType === 'base64') {
buffer = Buffer.from(data, 'base64')
} else if (fromType === 'base64url') {
buffer = base64url.toBuffer(data)
} else if (fromType === 'bn' || fromType === 'bignum') {
buffer = Buffer.from(this.pad(data.toString(16)), 'hex')
} else {
throw new Error('Invalid fromType')
}
if (toType === 'raw') {
return buffer
} else if (toType === 'uint8_array') {
return Array.from(buffer)
} else if (toType === 'hex') {
return buffer.toString('hex')
} else if (toType === 'base64') {
return buffer.toString('base64')
} else if (toType === 'base64url') {
return base64url.fromBase64(buffer.toString('base64'))
} else if (toType === 'bn' || toType === 'bignum') {
return new asn.bignum(buffer)
} else {
throw new Error('Invalid toType')
}
}
/**
* pad
*
* @description
* Pad a hex string for octet parsing
*
* @param {String} hex
* @return {String}
*/
static pad (hex) {
return hex.length % 2 === 1 ? `0${hex}` : hex
}
}
/**
* Export
* @ignore
*/
module.exports = Converter