module Net::IMAP::StringPrep
Regexps and utility methods for implementing stringprep profiles. The StringPrep algorithm is defined by RFC-3454. Each codepoint table defined in the RFC-3454 appendices is matched by a Regexp defined in this module.
Public Class Methods
Returns a Regexp matching the given table
name.
# File net-imap-0.4.9.1/lib/net/imap/stringprep.rb, line 49 def self.[](table) Tables::REGEXPS.fetch(table) end
Public Instance Methods
Checks that string
obeys all of the “Bidirectional Characters” requirements in RFC-3454, §6:
-
The characters in StringPrep["C.8"] MUST be prohibited
-
If a string contains any RandALCat character, the string MUST NOT contain any LCat character.
-
If a string contains any RandALCat character, a RandALCat character MUST be the first character of the string, and a RandALCat character MUST be the last character of the string.
This is usually combined with check_prohibited!
, so table “C.8” is only checked when c_8: true
.
Raises either ProhibitedCodepoint
or BidiStringError
unless all requirements are met. profile
is an optional string which will be added to any exception that is raised (it does not affect behavior).
# File net-imap-0.4.9.1/lib/net/imap/stringprep.rb, line 144 def check_bidi!(string, c_8: false, profile: nil) check_prohibited!(string, "C.8", profile: profile) if c_8 if Tables::BIDI_FAILS_REQ2.match?(string) raise BidiStringError.new( Tables::BIDI_DESC_REQ2, string: string, profile: profile, ) elsif Tables::BIDI_FAILS_REQ3.match?(string) raise BidiStringError.new( Tables::BIDI_DESC_REQ3, string: string, profile: profile, ) end end
Checks string
for any codepoint in tables
. Raises a ProhibitedCodepoint
describing the first matching table.
Also checks bidirectional characters, when bidi: true
, which may raise a BidiStringError
.
profile
is an optional string which will be added to any exception that is raised (it does not affect behavior).
# File net-imap-0.4.9.1/lib/net/imap/stringprep.rb, line 104 def check_prohibited!(string, *tables, bidi: false, unassigned: "A.1", stored: false, profile: nil) tables = Tables::TITLES.keys.grep(/^C/) if tables.empty? tables |= [unassigned] if stored tables |= %w[C.8] if bidi table = tables.find {|t| case t when String then Tables::REGEXPS.fetch(t).match?(string) when Regexp then t.match?(string) else raise ArgumentError, "only table names and regexps can be checked" end } if table raise ProhibitedCodepoint.new( table, string: string, profile: profile ) end check_bidi!(string, profile: profile) if bidi end
# File net-imap-0.4.9.1/lib/net/imap/stringprep.rb, line 88 def map_tables!(string, *tables) tables.each do |table| regexp, replacements = Tables::MAPPINGS.fetch(table) string.gsub!(regexp, replacements) end string end
Map – For each character in the input, check if it has a mapping and, if so, replace it with its mapping. This is described in section 3.
Normalize – Possibly normalize the result of step 1 using Unicode normalization. This is described in section 4.
Prohibit – Check for any characters that are not allowed in the output. If any are found, return an error. This is described in section 5.
Check bidi – Possibly check for right-to-left characters, and if any are found, make sure that the whole string satisfies the requirements for bidirectional strings. If the string does not satisfy the requirements for bidirectional strings, return an error. This is described in section 6.
The above steps MUST be performed in the order given to comply with this specification.
# File net-imap-0.4.9.1/lib/net/imap/stringprep.rb, line 76 def stringprep(string, maps:, normalization:, prohibited:, **opts) string = string.encode("UTF-8") # also dups (and raises invalid encoding) map_tables!(string, *maps) if maps string.unicode_normalize!(normalization) if normalization check_prohibited!(string, *prohibited, **opts) if prohibited string end