2.5.3.4 Converting an X.500 Distinguish Name to a String

The Subject name field of an X.509 certificate ([RFC3280] section 4.1.2.6) is converted to a string according to [RFC1779] but with the following deviations:

1. <spaced-separator> is defined as a comma, followed by a space character:

   <spaced-separator> ::= "," " " 

2. No optional space characters are added when converting attributes:

   <attribute> ::= <string> | <key> "=" <string>

3. If the attribute type is listed in the following table, the corresponding keyword is used.

   Object Identifier	Keyword
   2.5.4.3	CN
   2.5.4.7	L
   2.5.4.10	O
   2.5.4.11	OU
   1.2.840.113549.1.9.1	E
   2.5.4.6	C
   2.5.4.8	S
   2.5.4.9	STREET
   2.5.4.12	T
   2.5.4.42	G
   2.5.4.43	I
   2.5.4.4	SN
   2.5.4.5	SERIALNUMBER
   0.9.2342.19200300.100.1.25	DC
   2.5.4.13	Description
   2.5.4.17	PostalCode
   2.5.4.18	POBox
   2.5.4.20	Phone

4. If the attribute type is not listed, the attribute is represented by the prefix "OID.", followed by the dotted-decimal representation of the OBJECT IDENTIFIER. For example,

   CN=John Doe, OID.1.3.6.1.4.1.311.1.1=Sample Text

5. Double quotation characters (") are added around a converted attribute value if:

   • a leading or trailing space character is present

   • one or more of the following characters are present:

     • Comma (,)

     • Plus sign (+)

     • Equal sign (=)

     • ASCII line feed character (decimal 10)

     • Less than sign (<)

     • Greater than sign (>)

     • Number sign (#)

     • Semicolon (;)

     • Single quotation (')

6. Single quotation characters (') are added around a converted attribute value if the double quotation character (") is present.

7. Strings that contain consecutive spaces are not enclosed within quotation marks.

8. Empty strings are enclosed within double quotation marks.