module Net::IMAP::StringPrep::SASLprep
SASLprep#saslprep
can be used to prepare a string according to [RFC4013].
SASLprep maps characters three ways: to nothing, to space, and Unicode normalization form KC. SASLprep prohibits codepoints from nearly all standard StringPrep
tables (RFC3454, Appendix “C”), and uses StringPrep’s standard bidirectional characters requirements (Appendix “D”). SASLprep also uses StringPrep’s definition of “Unassigned” codepoints (Appendix “A”).
Constants
- ASCII_NO_CTRLS
Used to short-circuit strings that don’t need preparation.
- BIDI_FAILURE
Bidirectional Characters [StringPrep, §6]
A Regexp for strings that don’t satisfy StringPrep’s Bidirectional Characters rules.
Equal to StringPrep::Tables::BIDI_FAILURE. Redefined here to avoid loading
StringPrep::Tables
unless necessary.- MAP_TO_NOTHING
RFC4013 §2.1 Mapping - mapped to nothing
the “commonly mapped to nothing” characters (StringPrep["B.1"]) that can be mapped to nothing.
Equal to StringPrep["B.1"]. Redefined here to avoid loading
StringPrep::Tables
unless necessary.- MAP_TO_SPACE
RFC4013 §2.1 Mapping - mapped to space
non-ASCII space characters (StringPrep["C.1.2"]) that can be mapped to SPACE (U+0020)
Equal to StringPrep["C.1.2"]. Redefined here to avoid loading
StringPrep::Tables
unless necessary.- PROHIBITED
A Regexp matching strings prohibited by RFC4013 §2.3 and §2.4.
This combines
PROHIBITED_OUTPUT
andBIDI_FAILURE
.- PROHIBITED_OUTPUT
A Regexp matching codepoints prohibited by RFC4013 §2.3.
This combines all of the
TABLES_PROHIBITED
tables.- PROHIBITED_OUTPUT_STORED
A Regexp matching codepoints prohibited by RFC4013 §2.3 and §2.5.
This combines
PROHIBITED_OUTPUT
andUNASSIGNED
.- PROHIBITED_STORED
A Regexp matching strings prohibited by RFC4013 §2.3, §2.4, and §2.5.
This combines
PROHIBITED_OUTPUT_STORED
andBIDI_FAILURE
.- TABLES_PROHIBITED
RFC4013 §2.3 Prohibited Output
-
Non-ASCII space characters — StringPrep["C.1.2"]
-
ASCII control characters — StringPrep["C.2.1"]
-
Non-ASCII control characters — StringPrep["C.2.2"]
-
Private Use characters — StringPrep["C.3"]
-
Non-character code points — StringPrep["C.4"]
-
Surrogate code points — StringPrep["C.5"]
-
Inappropriate for plain text characters — StringPrep["C.6"]
-
Inappropriate for canonical representation characters — StringPrep["C.7"]
-
Change display properties or deprecated characters — StringPrep["C.8"]
-
Tagging characters — StringPrep["C.9"]
-
- TABLES_PROHIBITED_STORED
Adds unassigned (by Unicode 3.2) codepoints to
TABLES_PROHIBITED
.RFC4013 §2.5 Unassigned Code Points
This profile specifies the StringPrep["A.1"] table as its list of unassigned code points.
- UNASSIGNED
RFC4013 §2.5 Unassigned Code Points
This profile specifies the StringPrep["A.1"] table as its list of unassigned code points.
Equal to StringPrep["A.1"]. Redefined here to avoid loading
StringPrep::Tables
unless necessary.
Public Instance Methods
Prepares a UTF-8 string
for comparison, using the SASLprep profile RFC4013 of the StringPrep
algorithm RFC3454.
By default, prohibited strings will return nil
. When exception
is true
, a StringPrepError
describing the violation will be raised.
When stored
is true
, “unassigned” codepoints will be prohibited. For StringPrep and the SASLprep profile, “unassigned” refers to Unicode 3.2, and not later versions. See RFC3454 §7 for more information.
# File net-imap-0.4.9.1/lib/net/imap/stringprep/saslprep.rb, line 42 def saslprep(str, stored: false, exception: false) return str if ASCII_NO_CTRLS.match?(str) # incompatible encoding raises str = str.encode("UTF-8") # also dups (and raises for invalid encoding) str.gsub!(MAP_TO_SPACE, " ") str.gsub!(MAP_TO_NOTHING, "") str.unicode_normalize!(:nfkc) # These regexps combine the prohibited and bidirectional checks return str unless str.match?(stored ? PROHIBITED_STORED : PROHIBITED) return nil unless exception # raise helpful errors to indicate *why* it failed: tables = stored ? TABLES_PROHIBITED_STORED : TABLES_PROHIBITED StringPrep.check_prohibited! str, *tables, bidi: true, profile: "SASLprep" raise InvalidStringError.new( "unknown error", string: string, profile: "SASLprep" ) rescue ArgumentError, Encoding::CompatibilityError => ex if /invalid byte sequence|incompatible encoding/.match? ex.message return nil unless exception raise StringPrepError.new(ex.message, string: str, profile: "saslprep") end raise ex end