dhc-common

Contains code that is common across digital health cards (vc and eu dgc)

Card Verifications

Verification covers:

1. Identity level
   1. For v1, SafetyPASS just show the person's picture does NOT name check
2. Vaccination Credential Level
   1. Cards signature verifications
      1. Get issuers public key - passed/failed
      2. Verify card signature with issuers public key - passed/failed/not-checked
   2. Card expired
      1. Verify card not expired using exp - passed/failed/one
   3. The issuer verifications
      1. The issuer is on the CommonTrust or EP3 networks whitelist - passed/failed
   4. The immunization requirements
      1. Is a trusted vaccine - may vary by country - passed/failed
      2. Vaccine specific
         1. The required number of shots have been had
         2. The time between doses was not exceeded, for example 17-92 days
         3. At least some number of days (typically 14) has elapsed since last dose
         4. future - Booster shots TDB how to handle

The card states are as follows, the order is ranked so check in that order

1. UnKnown no verifications have been performed
2. Valid (Green)
   1. The card structure verifications have passed
   2. The card has not expired
   3. The issuer is trusted
   4. The immunization requirements have been met
3. Corrupted Card (Red)
   1. Fetched issuer key and the signature is bad no other checks made
      1. Note invalid cards cannot be loaded, but maybe something happened since loaded, or issuer key changed
4. UnVerified (Orange) if cannot check signature then all else is untrusted
   • get key failed so cannot check signature
5. Safety Criteria Not Met (Orange) if safety criteria are not met does not matter if issuer is unknown or expired
   • vaccine on whitelist: passed/failed
   • required number shots have been met: passed/failed
   • The time between doses was not exceeded, for example 17-92 days: passed/failed
   • At least some number of days (typically 14) has elapsed since last dose: passed/failed
6. Issuer Unknown -(Orange) if issuer unknown then cannot trust
   • issuer trusted - failed
7. Expired - (Orange) if expired but trusted issuer and safety checks made it may be ok
   • card expired