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import { isCloudflareWorkers, isNodeJs } from './env.ts'import { JOSENotSupported } from '../util/errors.ts'
export default function subtleDsa(alg: string, namedCurve?: string) {  const length = parseInt(alg.substr(-3), 10)  switch (alg) {    case 'HS256':    case 'HS384':    case 'HS512':      return { hash: `SHA-${length}`, name: 'HMAC' }    case 'PS256':    case 'PS384':    case 'PS512':      return { hash: `SHA-${length}`, name: 'RSA-PSS', saltLength: length >> 3 }    case 'RS256':    case 'RS384':    case 'RS512':      return { hash: `SHA-${length}`, name: 'RSASSA-PKCS1-v1_5' }    case 'ES256':    case 'ES384':    case 'ES512':      return { hash: `SHA-${length}`, name: 'ECDSA', namedCurve }    case (isCloudflareWorkers() || isNodeJs()) && 'EdDSA':      return <EcKeyAlgorithm>{ name: namedCurve, namedCurve }    default:      throw new JOSENotSupported(        `alg ${alg} is not supported either by JOSE or your javascript runtime`,      )  }}