用戶憑證（Subscriber Certificate）之通用名稱（Common Name）屬性

Subscriber Certificate Common Name Attribute

If present, this attribute MUST contain exactly one entry that is one of the values contained in the Certificate’s subjectAltName extension (see Section 7.1.2.7.12). The value of the field MUST be encoded as follows:

• If the value is an IPv4 address, then the value MUST be encoded as an IPv4Address as specified in RFC 3986, Section 3.2.2.
• If the value is an IPv6 address, then the value MUST be encoded in the text representation specified in RFC 5952, Section 4.
• If the value is a Fully-Qualified Domain Name or Wildcard Domain Name, then the value MUST be encoded as a character-for-character copy of the dNSName entry value from the subjectAltName extension. Specifically, all Domain Labels of the Fully-Qualified Domain Name or FQDN portion of the Wildcard Domain Name must be encoded as LDH Labels, and P-Labels MUST NOT be converted to their Unicode representation.

若此屬性存在，應（MUST）包含僅有一個項目，且該項目為憑證 subjectAltName 擴充欄位中所含值之一（參見第 7.1.2.7.12 節）。該欄位值應（MUST）依下列方式編碼：

• 若值為 IPv4 位址，則該值應（MUST）依 RFC 3986 第 3.2.2 節 之規定，以 IPv4Address 格式編碼。
• 若值為 IPv6 位址，則該值應（MUST）依 RFC 5952 第 4 節 所規定之文字表示方式編碼。
• 若值為完全吻合網域名稱（FQDN）或萬用網域名稱（Wildcard Domain Name），則該值應（MUST）逐字元複製 subjectAltName 擴充欄位中 dNSName 項目的值。具體而言，完全吻合網域名稱的所有網域標籤（Domain Labels），或萬用網域名稱 FQDN 部分的所有網域標籤，均須以 LDH 標籤（LDH Labels）格式編碼，且 P-Labels 不得（MUST NOT）轉換為 Unicode 表示形式。