RFCRFC5280とは（X.509 PKI 証明書と CRL プロファイル）
What is RFC5280 ? (X.509 PKI Certificates and CRL Profiles)
RFC
RFCRFCRFC2119とは【MUST, SHALL, SHOULD, MAYの違い】
What is RFC2119 [Difference between MUST, SHALL, SHOULD, and MAY]?
RFCRFC3647とは(CP/CPS関連)
RFC3647（Internet X.509 PKI Certificate Policy and Certification Practices Framework）.CP/CPS.
RFC電子証明書の有効期間計算（Validity）【RFC5280】
Calculation of the validity period of digital certificates.