Postgres 14

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CREATE EXTENSION

with invar as (
  select '-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----' as cert
)
select regexp_replace(  --deal with '+', replace them with '-'
        rtrim(          -- deal with trailing = signs
         encode(                -- base64 of sha256 hash
           digest(              -- create sha256 hash
             decode(            -- get cert bytes from base64
               regexp_replace(  -- remove BEGIN and END lines
                 cert, '(-.*?-)', '', 'g'
               ),
               'base64'
             ),
             'sha256'
           ),
           'base64'
         ),
         '='
       ),'\+','-','g')
       
  from invar;

regexp_replace
oMML7wEuEIZw2PNY6yRxe--liaOVUKizkxPRHOouiHs

SELECT 1