**Env**: Ubuntu x64 **Go version**: 1.13, 1.15 **Reproduce**: `./zcertificate seed-4s18-12s35-17s32-22s35-112s19-752s30-822s27.pem` **Expected result**: ``` X509v3 Policy Mappings: 2.5.29.32.1:1.3.5.8 ``` **Actual result**: ``` "unknown_extensions": [ ... { "id": "2.5.29.33", "critical": false, "value": "MA0wCwYEVR0gAQYDKwUI" } ``` **Attachment** [seed-4s18-12s35-17s32-22s35-112s19-752s30-822s27.zip](https://github.com/zmap/zcrypto/files/5867241/seed-4s18-12s35-17s32-22s35-112s19-752s30-822s27.zip)