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import { isNotNull, isString } from "./util.ts";
/* * JSW §1: Cryptographic algorithms and identifiers for use with this specification * are described in the separate JSON Web Algorithms (JWA) specification: * https://www.rfc-editor.org/rfc/rfc7518 */export type Algorithm =  | "HS256"  | "HS384"  | "HS512"  | "PS256"  | "PS384"  | "PS512"  | "RS256"  | "RS384"  | "RS512"  | "ES256"  | "ES384"  // P-521 is not yet supported.  // https://github.com/denoland/deno/blob/main/ext/crypto/00_crypto.js  | "none";
// Still needs an 'any' type! Does anyone have an idea?// https://github.com/denoland/deno/blob/main/ext/crypto/lib.deno_crypto.d.tsfunction isHashedKeyAlgorithm(  // deno-lint-ignore no-explicit-any  algorithm: Record<string, any>,): algorithm is HmacKeyAlgorithm | RsaHashedKeyAlgorithm {  return isString(algorithm.hash?.name);}
function isEcKeyAlgorithm(  // deno-lint-ignore no-explicit-any  algorithm: Record<string, any>,): algorithm is EcKeyAlgorithm {  return isString(algorithm.namedCurve);}
export function verify(alg: Algorithm, key: CryptoKey | null): boolean {  if (alg === "none") {    if (isNotNull(key)) {      throw new Error(`The alg '${alg}' does not allow a key.`);    } else return true;  } else {    if (!key) throw new Error(`The alg '${alg}' demands a key.`);    const keyAlgorithm = key.algorithm;    const algAlgorithm = getAlgorithm(alg);    if (keyAlgorithm.name === algAlgorithm.name) {      if (isHashedKeyAlgorithm(keyAlgorithm)) {        return keyAlgorithm.hash.name === algAlgorithm.hash.name;      } else if (isEcKeyAlgorithm(keyAlgorithm)) {        return keyAlgorithm.namedCurve === algAlgorithm.namedCurve;      }    }    return false;  }}
export function getAlgorithm(alg: Algorithm) {  switch (alg) {    case "HS256":      return { hash: { name: "SHA-256" }, name: "HMAC" };    case "HS384":      return { hash: { name: "SHA-384" }, name: "HMAC" };    case "HS512":      return { hash: { name: "SHA-512" }, name: "HMAC" };    case "PS256":      return {        hash: { name: "SHA-256" },        name: "RSA-PSS",        saltLength: 256 >> 3,      };    case "PS384":      return {        hash: { name: "SHA-384" },        name: "RSA-PSS",        saltLength: 384 >> 3,      };    case "PS512":      return {        hash: { name: "SHA-512" },        name: "RSA-PSS",        saltLength: 512 >> 3,      };    case "RS256":      return { hash: { name: "SHA-256" }, name: "RSASSA-PKCS1-v1_5" };    case "RS384":      return { hash: { name: "SHA-384" }, name: "RSASSA-PKCS1-v1_5" };    case "RS512":      return { hash: { name: "SHA-512" }, name: "RSASSA-PKCS1-v1_5" };    case "ES256":      return { hash: { name: "SHA-256" }, name: "ECDSA", namedCurve: "P-256" };    case "ES384":      return { hash: { name: "SHA-384" }, name: "ECDSA", namedCurve: "P-384" };    // case "ES512":    // return { hash: { name: "SHA-512" }, name: "ECDSA", namedCurve: "P-521" };    default:      throw new Error(`The jwt's alg '${alg}' is not supported.`);  }}