lesspass/mobile/ios/LessPassModule.swift

import Foundation

enum HMACAlgorithm {
    case MD5, SHA1, SHA224, SHA256, SHA384, SHA512

    func toCCHmacAlgorithm() -> CCHmacAlgorithm {
        var result: Int = 0
        switch self {
        case .MD5:
            result = kCCHmacAlgMD5
        case .SHA1:
            result = kCCHmacAlgSHA1
        case .SHA224:
            result = kCCHmacAlgSHA224
        case .SHA256:
            result = kCCHmacAlgSHA256
        case .SHA384:
            result = kCCHmacAlgSHA384
        case .SHA512:
            result = kCCHmacAlgSHA512
        }
        return CCHmacAlgorithm(result)
    }

    func digestLength() -> Int {
        var result: CInt = 0
        switch self {
        case .MD5:
            result = CC_MD5_DIGEST_LENGTH
        case .SHA1:
            result = CC_SHA1_DIGEST_LENGTH
        case .SHA224:
            result = CC_SHA224_DIGEST_LENGTH
        case .SHA256:
            result = CC_SHA256_DIGEST_LENGTH
        case .SHA384:
            result = CC_SHA384_DIGEST_LENGTH
        case .SHA512:
            result = CC_SHA512_DIGEST_LENGTH
        }
        return Int(result)
    }
}

extension String {
    func hmac(algorithm: HMACAlgorithm, key: String) -> String {
      let cKey = key.cString(using: String.Encoding.utf8)
      let cData = self.cString(using: String.Encoding.utf8)
      var result = [CUnsignedChar](repeating: 0, count: Int(algorithm.digestLength()))
      CCHmac(algorithm.toCCHmacAlgorithm(), cKey!, Int(strlen(cKey!)), cData!, Int(strlen(cData!)), &result)
      let hmacData:NSData = NSData(bytes: result, length: (Int(algorithm.digestLength())))
      var bytes = [UInt8](repeating:0, count: hmacData.length)
      hmacData.getBytes(&bytes, length: hmacData.length)
      var hexString = ""
      for byte in bytes {
          hexString += String(format:"%02hhx", UInt8(byte))
      }
      return hexString
    }
}

@objc(LessPassModule)
class LessPassModule: NSObject {
  @objc(createFingerprint:resolver:rejecter:)
  func createFingerprint(_ masterPassword: String,
                         resolver resolve: RCTPromiseResolveBlock,
                         rejecter reject:RCTPromiseRejectBlock) -> Void {
    resolve("".hmac(algorithm: HMACAlgorithm.SHA256, key: masterPassword))
  }
  
  @objc
  static func requiresMainQueueSetup() -> Bool {
    return false
  }
}