gentoo-overlay/app-crypt/tpm-tools/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <herd>crypto</herd>
  <use>
    <flag name="pkcs11">
      Build Token data management utilities based on OpenCryptoki's
      (<pkg>dev-libs/opencryptoki</pkg>) PKCS#11 implementation.
    </flag>
  </use>
  <upstream>
    <remote-id type="sourceforge">trousers</remote-id>
  </upstream>
</pkgmetadata>