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https://hanzama.x0.to/2020/07/03/google-and-mozilla-also-shorten-the-tls-server-certificate-to-13-months-and-follow-apples-itmedia-server/
TLSサーバ証明書の最大有効期間、13カ月に短縮 GoogleやMozillaもAppleに追随(ITmedia)