[FIG(quote)[ [FIGCAPTION[ [1] [CITE@en[RFC 5280 - Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile]] ([TIME[2015-02-22 15:44:10 +09:00]] 版) ]FIGCAPTION] > Legacy implementations exist where an electronic mail address is > embedded in the subject distinguished name as an emailAddress > attribute '''['''RFC2985''']'''. The attribute value for emailAddress is of type > IA5String to permit inclusion of the character '@', which is not part > of the PrintableString character set. emailAddress attribute values > are not case-sensitive (e.g., "subscriber@example.com" is the same as > "SUBSCRIBER@EXAMPLE.COM"). > Conforming implementations generating new certificates with > electronic mail addresses MUST use the rfc822Name in the subject > alternative name extension (Section 4.2.1.6) to describe such > identities. Simultaneous inclusion of the emailAddress attribute in > the subject distinguished name to support legacy implementations is > deprecated but permitted. ]FIG] [FIG(quote)[ [FIGCAPTION[ [2] [CITE@en[RFC 5280 - Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile]] ([TIME[2015-02-22 15:44:10 +09:00]] 版) ]FIGCAPTION] > Legacy implementations exist where an electronic mail address is > embedded in the subject distinguished name in an attribute of type > emailAddress (Section 4.1.2.6). When constraints are imposed on the > Cooper, et al. Standards Track '''['''Page 41''']''' > page-42 > RFC 5280 PKIX Certificate and CRL Profile May 2008 > rfc822Name name form, but the certificate does not include a subject > alternative name, the rfc822Name constraint MUST be applied to the > attribute of type emailAddress in the subject distinguished name. ]FIG] [3] [CITE@en[RFC 2985 - PKCS #9: Selected Object Classes and Attribute Types Version 2.0]] ([TIME[2014-12-28 18:45:38 +09:00]] 版)