The International Association of Oil & Gas Producers (IOGP) EPSG Geodetic Parameter Dataset is available for download through their web site ~ http://www.epsg.org/.
However, if you have proj4 the EPSG codes should be available in your installation in a epsg
file at a location:
\bin\proj\SHARE\epsg
If you have proj6 the EPSG codes are contained in a sqlite3 database file proj.db
in a location like:
\bin\proj6\share\proj.db