certificate.ts

import * as asn1 from 'asn1js'
import { Certificate } from 'pkijs'

export function getSignatureAlgorithmDetails(oid: string): { signatureAlgorithm: string; hashFunction: string } {
  const details = {
    '1.2.840.113549.1.1.5': { signatureAlgorithm: 'rsa', hashFunction: 'sha1' },
    '1.2.840.113549.1.1.11': { signatureAlgorithm: 'rsa', hashFunction: 'sha256' },
    '1.2.840.113549.1.1.12': { signatureAlgorithm: 'rsa', hashFunction: 'sha384' },
    '1.2.840.113549.1.1.13': { signatureAlgorithm: 'rsa', hashFunction: 'sha512' },
    // rsapss
    '1.2.840.113549.1.1.10': { signatureAlgorithm: 'rsapss', hashFunction: 'sha256' }, // TODO: detect which hash function is used (not always sha256)
    // ecdsa
    '1.2.840.10045.4.1': { signatureAlgorithm: 'ecdsa', hashFunction: 'sha1' },
    '1.2.840.10045.4.3.1': { signatureAlgorithm: 'ecdsa', hashFunction: 'sha224' },
    '1.2.840.10045.4.3.2': { signatureAlgorithm: 'ecdsa', hashFunction: 'sha256' },
    '1.2.840.10045.4.3.3': { signatureAlgorithm: 'ecdsa', hashFunction: 'sha384' },
    '1.2.840.10045.4.3.4': { signatureAlgorithm: 'ecdsa', hashFunction: 'sha512' },
  }
  return details[oid] || { signatureAlgorithm: `Unknown (${oid})`, hashFunction: 'Unknown' }
}

export function getSignatureAlgorithm(pemContent: string) {
  const certBuffer = Buffer.from(pemContent.replace(/(-----(BEGIN|END) CERTIFICATE-----|\n)/g, ''), 'base64')
  const asn1Data = asn1.fromBER(certBuffer)
  const cert = new Certificate({ schema: asn1Data.result })
  const signatureAlgorithmOid = cert.signatureAlgorithm.algorithmId
  const { signatureAlgorithm, hashFunction } = getSignatureAlgorithmDetails(signatureAlgorithmOid)
  return { signatureAlgorithm, hashFunction }
}

export const getCircuitName = (circuitType: string, signatureAlgorithm: string, hashFunction: string) => {
  if (signatureAlgorithm === 'ecdsa')
    return circuitType + '_' + signatureAlgorithm + '_' + hashFunction
  else
    return circuitType + '_' + signatureAlgorithm + '_65537_' + hashFunction
}