Can't compile initial project for iOS

Description

When I create a new project via npx react-native init bestproject and trying to compile it on macOS I receive the following errors:

/Users/user/projects/bestproject/ios/Pods/OpenSSL-Universal/Frameworks/OpenSSL.xcframework/ios-arm64_arm64e_armv7_armv7s/openssl.framework/Headers/bn.h:186:39:
 Unknown type name 'BN_ULONG'
Flipper-Folly
/Users/user/projects/bestproject/ios/Pods/OpenSSL-Universal/Frameworks/OpenSSL.xcframework/ios-arm64_arm64e_armv7_armv7s/openssl.framework/Headers/bio.h:687:1:
 Expected function body after function declarator

React Native version:

System:
    OS: macOS 10.15.7
    CPU: (6) x64 Intel(R) Core(TM) i5-8500B CPU @ 3.00GHz
    Memory: 433.12 MB / 8.00 GB
    Shell: 3.2.57 - /bin/bash
  Binaries:
    Node: 14.10.1 - /usr/local/bin/node
    Yarn: 1.22.5 - /usr/local/bin/yarn
    npm: 6.14.10 - /usr/local/bin/npm
    Watchman: 4.9.0 - /usr/local/bin/watchman
  Managers:
    CocoaPods: 1.9.1 - /usr/local/bin/pod
  SDKs:
    iOS SDK:
      Platforms: iOS 14.3, DriverKit 20.2, macOS 11.1, tvOS 14.3, watchOS 7.2
    Android SDK: Not Found
  IDEs:
    Android Studio: 4.0 AI-193.6911.18.40.6626763
    Xcode: 12.3/12C33 - /usr/bin/xcodebuild
  Languages:
    Java: Not Found
    Python: 2.7.16 - /usr/bin/python
  npmPackages:
    @react-native-community/cli: Not Found
    react: 16.13.1 => 16.13.1 
    react-native: 0.63.4 => 0.63.4 
    react-native-macos: Not Found
  npmGlobalPackages:
    *react-native*: Not Found

Steps To Reproduce

1. npx react-native init bestproject
2. cd bestproject
3. pod install
4. Run project in xcode
5. Receive the errors

[EricWiener]

Building existing iOS projects also start failing with the same error(s) if OpenSSL-Universal gets updated to 1.1.180 via pod update. Rolling back to OpenSSL-Universal 1.0.2.20 (Flipper-Folly 2.3.0 and Flipper-RSocket 1.1.0) seems to get the iOS build working again.

In case anyone else is wondering how to do this, you need to add pod 'OpenSSL-Universal', '~>1.0.2.20' to your Podfile

[apperside]

@lauritaipale’s solution worked for me, adding this to my pod file fixed the problem:

pod ‘OpenSSL-Universal’, ‘~>1.0.2.20’

NOTE: after adding this, just running pod install will fire an error due to versions mismatch, in that case remove Podfile.lock and pod install again