123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136
import { unwrap as aesKw } from '../runtime/aeskw.ts'import * as ECDH from '../runtime/ecdhes.ts'import { decrypt as pbes2Kw } from '../runtime/pbes2kw.ts'import { decrypt as rsaEs } from '../runtime/rsaes.ts'import { decode as base64url } from '../runtime/base64url.ts'
import type { JWEHeaderParameters, KeyLike, JWK } from '../types.d.ts'import { JOSENotSupported, JWEInvalid } from '../util/errors.ts'import { bitLength as cekLength } from '../lib/cek.ts'import { importJWK } from '../key/import.ts'import checkKeyType from './check_key_type.ts'import isObject from './is_object.ts'import { unwrap as aesGcmKw } from './aesgcmkw.ts'
async function decryptKeyManagement(  alg: string,  key: KeyLike | Uint8Array,  encryptedKey: Uint8Array | undefined,  joseHeader: JWEHeaderParameters,): Promise<KeyLike | Uint8Array> {  checkKeyType(alg, key, 'decrypt')
  switch (alg) {    case 'dir': {      // Direct Encryption      if (encryptedKey !== undefined)        throw new JWEInvalid('Encountered unexpected JWE Encrypted Key')
      return key    }    case 'ECDH-ES':      // Direct Key Agreement      if (encryptedKey !== undefined)        throw new JWEInvalid('Encountered unexpected JWE Encrypted Key')
    case 'ECDH-ES+A128KW':    case 'ECDH-ES+A192KW':    case 'ECDH-ES+A256KW': {      // Direct Key Agreement      if (!isObject<JWK>(joseHeader.epk))        throw new JWEInvalid(`JOSE Header "epk" (Ephemeral Public Key) missing or invalid`)
      if (!ECDH.ecdhAllowed(key))        throw new JOSENotSupported(          'ECDH with the provided key is not allowed or not supported by your javascript runtime',        )
      const epk = await importJWK(joseHeader.epk, alg)      let partyUInfo!: Uint8Array      let partyVInfo!: Uint8Array
      if (joseHeader.apu !== undefined) {        if (typeof joseHeader.apu !== 'string')          throw new JWEInvalid(`JOSE Header "apu" (Agreement PartyUInfo) invalid`)        partyUInfo = base64url(joseHeader.apu)      }
      if (joseHeader.apv !== undefined) {        if (typeof joseHeader.apv !== 'string')          throw new JWEInvalid(`JOSE Header "apv" (Agreement PartyVInfo) invalid`)        partyVInfo = base64url(joseHeader.apv)      }
      const sharedSecret = await ECDH.deriveKey(        epk,        key,        alg === 'ECDH-ES' ? joseHeader.enc! : alg,        alg === 'ECDH-ES' ? cekLength(joseHeader.enc!) : parseInt(alg.slice(-5, -2), 10),        partyUInfo,        partyVInfo,      )
      if (alg === 'ECDH-ES') return sharedSecret
      // Key Agreement with Key Wrapping      if (encryptedKey === undefined) throw new JWEInvalid('JWE Encrypted Key missing')
      return aesKw(alg.slice(-6), sharedSecret, encryptedKey)    }    case 'RSA1_5':    case 'RSA-OAEP':    case 'RSA-OAEP-256':    case 'RSA-OAEP-384':    case 'RSA-OAEP-512': {      // Key Encryption (RSA)      if (encryptedKey === undefined) throw new JWEInvalid('JWE Encrypted Key missing')
      return rsaEs(alg, key, encryptedKey)    }    case 'PBES2-HS256+A128KW':    case 'PBES2-HS384+A192KW':    case 'PBES2-HS512+A256KW': {      // Key Encryption (PBES2)      if (encryptedKey === undefined) throw new JWEInvalid('JWE Encrypted Key missing')
      if (typeof joseHeader.p2c !== 'number')        throw new JWEInvalid(`JOSE Header "p2c" (PBES2 Count) missing or invalid`)
      if (typeof joseHeader.p2s !== 'string')        throw new JWEInvalid(`JOSE Header "p2s" (PBES2 Salt) missing or invalid`)
      return pbes2Kw(alg, key, encryptedKey, joseHeader.p2c, base64url(joseHeader.p2s))    }    case 'A128KW':    case 'A192KW':    case 'A256KW': {      // Key Wrapping (AES KW)      if (encryptedKey === undefined) throw new JWEInvalid('JWE Encrypted Key missing')
      return aesKw(alg, key, encryptedKey)    }    case 'A128GCMKW':    case 'A192GCMKW':    case 'A256GCMKW': {      // Key Wrapping (AES GCM KW)      if (encryptedKey === undefined) throw new JWEInvalid('JWE Encrypted Key missing')
      if (typeof joseHeader.iv !== 'string')        throw new JWEInvalid(`JOSE Header "iv" (Initialization Vector) missing or invalid`)
      if (typeof joseHeader.tag !== 'string')        throw new JWEInvalid(`JOSE Header "tag" (Authentication Tag) missing or invalid`)
      const iv = base64url(joseHeader.iv)      const tag = base64url(joseHeader.tag)
      return aesGcmKw(alg, key, encryptedKey, iv, tag)    }    default: {      throw new JOSENotSupported('Invalid or unsupported "alg" (JWE Algorithm) header value')    }  }}
export default decryptKeyManagement