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Module: Net::IMAP::SASL::SASLprep

Relationships & Source Files
Defined in: lib/net/imap/sasl/saslprep.rb,
lib/net/imap/sasl/saslprep_tables.rb

Overview

#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”).

Constant Summary

  • ASCII_NO_CTRLS =

    Used to short-circuit strings that don’t need preparation.

    # File 'lib/net/imap/sasl/saslprep.rb', line 17 
    /\A[\x20-\x7e]*\z/u.freeze
  • BIDI_FAILURE =

    Bidirectional Characters [StringPrep, §6]

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 68 
    /(?mx-i: # RandALCat followed by LCat
  (?<r_and_al_cat>[\u{05be 05c0 05c3 061b 061f 06dd 0710 07b1 200f fb1d fb3e}\u{05d0}-\u{05ea}\u{05f0}-\u{05f4}\u{0621}-\u{063a}\u{0640}-\u{064a}\u{066d}-\u{066f}\u{0671}-\u{06d5}\u{06e5}-\u{06e6}\u{06fa}-\u{06fe}\u{0700}-\u{070d}\u{0712}-\u{072c}\u{0780}-\u{07a5}\u{fb1f}-\u{fb28}\u{fb2a}-\u{fb36}\u{fb38}-\u{fb3c}\u{fb40}-\u{fb41}\u{fb43}-\u{fb44}\u{fb46}-\u{fbb1}\u{fbd3}-\u{fd3d}\u{fd50}-\u{fd8f}\u{fd92}-\u{fdc7}\u{fdf0}-\u{fdfc}\u{fe70}-\u{fe74}\u{fe76}-\u{fefc}])
    .*?
    (?<l_cat>[\u{00aa 00b5 00ba 02ee 037a 0386 038c 0589 0903 0950 09b2 09d7 0a5e 0a83 0a8d 0ac9 0ad0 0ae0 0b40 0b57 0b83 0b9c 0bd7 0cbe 0cde 0d57 0dbd 0e84 0e8a 0e8d 0ea5 0ea7 0ebd 0ec6 0f36 0f38 0f7f 0f85 0fcf 102c 1031 1038 10fb 1248 1258 1288 12b0 12c0 1310 17dc 1f59 1f5b 1f5d 1fbe 200e 2071 207f 2102 2107 2115 2124 2126 2128 2395 1d4a2 1d4bb 1d546}\u{0041}-\u{005a}\u{0061}-\u{007a}\u{00c0}-\u{00d6}\u{00d8}-\u{00f6}\u{00f8}-\u{0220}\u{0222}-\u{0233}\u{0250}-\u{02ad}\u{02b0}-\u{02b8}\u{02bb}-\u{02c1}\u{02d0}-\u{02d1}\u{02e0}-\u{02e4}\u{0388}-\u{038a}\u{038e}-\u{03a1}\u{03a3}-\u{03ce}\u{03d0}-\u{03f5}\u{0400}-\u{0482}\u{048a}-\u{04ce}\u{04d0}-\u{04f5}\u{04f8}-\u{04f9}\u{0500}-\u{050f}\u{0531}-\u{0556}\u{0559}-\u{055f}\u{0561}-\u{0587}\u{0905}-\u{0939}\u{093d}-\u{0940}\u{0949}-\u{094c}\u{0958}-\u{0961}\u{0964}-\u{0970}\u{0982}-\u{0983}\u{0985}-\u{098c}\u{098f}-\u{0990}\u{0993}-\u{09a8}\u{09aa}-\u{09b0}\u{09b6}-\u{09b9}\u{09be}-\u{09c0}\u{09c7}-\u{09c8}\u{09cb}-\u{09cc}\u{09dc}-\u{09dd}\u{09df}-\u{09e1}\u{09e6}-\u{09f1}\u{09f4}-\u{09fa}\u{0a05}-\u{0a0a}\u{0a0f}-\u{0a10}\u{0a13}-\u{0a28}\u{0a2a}-\u{0a30}\u{0a32}-\u{0a33}\u{0a35}-\u{0a36}\u{0a38}-\u{0a39}\u{0a3e}-\u{0a40}\u{0a59}-\u{0a5c}\u{0a66}-\u{0a6f}\u{0a72}-\u{0a74}\u{0a85}-\u{0a8b}\u{0a8f}-\u{0a91}\u{0a93}-\u{0aa8}\u{0aaa}-\u{0ab0}\u{0ab2}-\u{0ab3}\u{0ab5}-\u{0ab9}\u{0abd}-\u{0ac0}\u{0acb}-\u{0acc}\u{0ae6}-\u{0aef}\u{0b02}-\u{0b03}\u{0b05}-\u{0b0c}\u{0b0f}-\u{0b10}\u{0b13}-\u{0b28}\u{0b2a}-\u{0b30}\u{0b32}-\u{0b33}\u{0b36}-\u{0b39}\u{0b3d}-\u{0b3e}\u{0b47}-\u{0b48}\u{0b4b}-\u{0b4c}\u{0b5c}-\u{0b5d}\u{0b5f}-\u{0b61}\u{0b66}-\u{0b70}\u{0b85}-\u{0b8a}\u{0b8e}-\u{0b90}\u{0b92}-\u{0b95}\u{0b99}-\u{0b9a}\u{0b9e}-\u{0b9f}\u{0ba3}-\u{0ba4}\u{0ba8}-\u{0baa}\u{0bae}-\u{0bb5}\u{0bb7}-\u{0bb9}\u{0bbe}-\u{0bbf}\u{0bc1}-\u{0bc2}\u{0bc6}-\u{0bc8}\u{0bca}-\u{0bcc}\u{0be7}-\u{0bf2}\u{0c01}-\u{0c03}\u{0c05}-\u{0c0c}\u{0c0e}-\u{0c10}\u{0c12}-\u{0c28}\u{0c2a}-\u{0c33}\u{0c35}-\u{0c39}\u{0c41}-\u{0c44}\u{0c60}-\u{0c61}\u{0c66}-\u{0c6f}\u{0c82}-\u{0c83}\u{0c85}-\u{0c8c}\u{0c8e}-\u{0c90}\u{0c92}-\u{0ca8}\u{0caa}-\u{0cb3}\u{0cb5}-\u{0cb9}\u{0cc0}-\u{0cc4}\u{0cc7}-\u{0cc8}\u{0cca}-\u{0ccb}\u{0cd5}-\u{0cd6}\u{0ce0}-\u{0ce1}\u{0ce6}-\u{0cef}\u{0d02}-\u{0d03}\u{0d05}-\u{0d0c}\u{0d0e}-\u{0d10}\u{0d12}-\u{0d28}\u{0d2a}-\u{0d39}\u{0d3e}-\u{0d40}\u{0d46}-\u{0d48}\u{0d4a}-\u{0d4c}\u{0d60}-\u{0d61}\u{0d66}-\u{0d6f}\u{0d82}-\u{0d83}\u{0d85}-\u{0d96}\u{0d9a}-\u{0db1}\u{0db3}-\u{0dbb}\u{0dc0}-\u{0dc6}\u{0dcf}-\u{0dd1}\u{0dd8}-\u{0ddf}\u{0df2}-\u{0df4}\u{0e01}-\u{0e30}\u{0e32}-\u{0e33}\u{0e40}-\u{0e46}\u{0e4f}-\u{0e5b}\u{0e81}-\u{0e82}\u{0e87}-\u{0e88}\u{0e94}-\u{0e97}\u{0e99}-\u{0e9f}\u{0ea1}-\u{0ea3}\u{0eaa}-\u{0eab}\u{0ead}-\u{0eb0}\u{0eb2}-\u{0eb3}\u{0ec0}-\u{0ec4}\u{0ed0}-\u{0ed9}\u{0edc}-\u{0edd}\u{0f00}-\u{0f17}\u{0f1a}-\u{0f34}\u{0f3e}-\u{0f47}\u{0f49}-\u{0f6a}\u{0f88}-\u{0f8b}\u{0fbe}-\u{0fc5}\u{0fc7}-\u{0fcc}\u{1000}-\u{1021}\u{1023}-\u{1027}\u{1029}-\u{102a}\u{1040}-\u{1057}\u{10a0}-\u{10c5}\u{10d0}-\u{10f8}\u{1100}-\u{1159}\u{115f}-\u{11a2}\u{11a8}-\u{11f9}\u{1200}-\u{1206}\u{1208}-\u{1246}\u{124a}-\u{124d}\u{1250}-\u{1256}\u{125a}-\u{125d}\u{1260}-\u{1286}\u{128a}-\u{128d}\u{1290}-\u{12ae}\u{12b2}-\u{12b5}\u{12b8}-\u{12be}\u{12c2}-\u{12c5}\u{12c8}-\u{12ce}\u{12d0}-\u{12d6}\u{12d8}-\u{12ee}\u{12f0}-\u{130e}\u{1312}-\u{1315}\u{1318}-\u{131e}\u{1320}-\u{1346}\u{1348}-\u{135a}\u{1361}-\u{137c}\u{13a0}-\u{13f4}\u{1401}-\u{1676}\u{1681}-\u{169a}\u{16a0}-\u{16f0}\u{1700}-\u{170c}\u{170e}-\u{1711}\u{1720}-\u{1731}\u{1735}-\u{1736}\u{1740}-\u{1751}\u{1760}-\u{176c}\u{176e}-\u{1770}\u{1780}-\u{17b6}\u{17be}-\u{17c5}\u{17c7}-\u{17c8}\u{17d4}-\u{17da}\u{17e0}-\u{17e9}\u{1810}-\u{1819}\u{1820}-\u{1877}\u{1880}-\u{18a8}\u{1e00}-\u{1e9b}\u{1ea0}-\u{1ef9}\u{1f00}-\u{1f15}\u{1f18}-\u{1f1d}\u{1f20}-\u{1f45}\u{1f48}-\u{1f4d}\u{1f50}-\u{1f57}\u{1f5f}-\u{1f7d}\u{1f80}-\u{1fb4}\u{1fb6}-\u{1fbc}\u{1fc2}-\u{1fc4}\u{1fc6}-\u{1fcc}\u{1fd0}-\u{1fd3}\u{1fd6}-\u{1fdb}\u{1fe0}-\u{1fec}\u{1ff2}-\u{1ff4}\u{1ff6}-\u{1ffc}\u{210a}-\u{2113}\u{2119}-\u{211d}\u{212a}-\u{212d}\u{212f}-\u{2131}\u{2133}-\u{2139}\u{213d}-\u{213f}\u{2145}-\u{2149}\u{2160}-\u{2183}\u{2336}-\u{237a}\u{249c}-\u{24e9}\u{3005}-\u{3007}\u{3021}-\u{3029}\u{3031}-\u{3035}\u{3038}-\u{303c}\u{3041}-\u{3096}\u{309d}-\u{309f}\u{30a1}-\u{30fa}\u{30fc}-\u{30ff}\u{3105}-\u{312c}\u{3131}-\u{318e}\u{3190}-\u{31b7}\u{31f0}-\u{321c}\u{3220}-\u{3243}\u{3260}-\u{327b}\u{327f}-\u{32b0}\u{32c0}-\u{32cb}\u{32d0}-\u{32fe}\u{3300}-\u{3376}\u{337b}-\u{33dd}\u{33e0}-\u{33fe}\u{3400}-\u{4db5}\u{4e00}-\u{9fa5}\u{a000}-\u{a48c}\u{ac00}-\u{d7a3}\u{e000}-\u{fa2d}\u{fa30}-\u{fa6a}\u{fb00}-\u{fb06}\u{fb13}-\u{fb17}\u{ff21}-\u{ff3a}\u{ff41}-\u{ff5a}\u{ff66}-\u{ffbe}\u{ffc2}-\u{ffc7}\u{ffca}-\u{ffcf}\u{ffd2}-\u{ffd7}\u{ffda}-\u{ffdc}\u{10300}-\u{1031e}\u{10320}-\u{10323}\u{10330}-\u{1034a}\u{10400}-\u{10425}\u{10428}-\u{1044d}\u{1d000}-\u{1d0f5}\u{1d100}-\u{1d126}\u{1d12a}-\u{1d166}\u{1d16a}-\u{1d172}\u{1d183}-\u{1d184}\u{1d18c}-\u{1d1a9}\u{1d1ae}-\u{1d1dd}\u{1d400}-\u{1d454}\u{1d456}-\u{1d49c}\u{1d49e}-\u{1d49f}\u{1d4a5}-\u{1d4a6}\u{1d4a9}-\u{1d4ac}\u{1d4ae}-\u{1d4b9}\u{1d4bd}-\u{1d4c0}\u{1d4c2}-\u{1d4c3}\u{1d4c5}-\u{1d505}\u{1d507}-\u{1d50a}\u{1d50d}-\u{1d514}\u{1d516}-\u{1d51c}\u{1d51e}-\u{1d539}\u{1d53b}-\u{1d53e}\u{1d540}-\u{1d544}\u{1d54a}-\u{1d550}\u{1d552}-\u{1d6a3}\u{1d6a8}-\u{1d7c9}\u{20000}-\u{2a6d6}\u{2f800}-\u{2fa1d}\u{f0000}-\u{ffffd}\u{100000}-\u{10fffd}\p{Cs}])
  | # RandALCat preceded by LCat
    \g<l_cat> .*? \g<r_and_al_cat>
) | (?mx-i: # contains RandALCat but doesn't start with RandALCat
  \A(?<not_r_nor_al>(?-mix:[^\u{05be 05c0 05c3 061b 061f 06dd 0710 07b1 200f fb1d fb3e}\u{05d0}-\u{05ea}\u{05f0}-\u{05f4}\u{0621}-\u{063a}\u{0640}-\u{064a}\u{066d}-\u{066f}\u{0671}-\u{06d5}\u{06e5}-\u{06e6}\u{06fa}-\u{06fe}\u{0700}-\u{070d}\u{0712}-\u{072c}\u{0780}-\u{07a5}\u{fb1f}-\u{fb28}\u{fb2a}-\u{fb36}\u{fb38}-\u{fb3c}\u{fb40}-\u{fb41}\u{fb43}-\u{fb44}\u{fb46}-\u{fbb1}\u{fbd3}-\u{fd3d}\u{fd50}-\u{fd8f}\u{fd92}-\u{fdc7}\u{fdf0}-\u{fdfc}\u{fe70}-\u{fe74}\u{fe76}-\u{fefc}]))
    .*?
    g<r_and_al_cat>
  | # contains RandALCat but doesn't end with RandALCat
    \g<r_and_al_cat> .*? \g<not_r_nor_al>\z
)/mx.freeze
  • 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. Redefined here to avoid loading the StringPrep module.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 25 
    /[\u{00ad 034f 1806 2060 feff}\u{180b}-\u{180d}\u{200b}-\u{200d}\u{fe00}-\u{fe0f}]/.freeze
  • MAP_TO_SPACE =

    RFC4013 §2.1 Mapping - mapped to space

    • non-ASCII space characters (StringPrep) that can be mapped to SPACE (U+0020), and

    Equal to StringPrep. Redefined here to avoid loading the StringPrep module.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 17 
    /[\u200b\p{Zs}&&[^ ]]/.freeze
  • PROHIBITED =

    Matches strings prohibited by RFC4013 §2.3 and §2.4.

    This checks prohibited output and bidirectional characters.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 85 
    Regexp.union(
  PROHIBITED_OUTPUT, BIDI_FAILURE,
)
  • PROHIBITED_OUTPUT =

    Matches codepoints prohibited by RFC4013 §2.3.

    See TABLES_PROHIBITED.

    Equal to Regexp.union of the TABLES_PROHIBITED tables. Redefined here to avoid loading the StringPrep module unless necessary.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 53 
    /[\u{06dd 070f 1680 180e 3000 feff e0001}\u{0000}-\u{001f}\u{007f}-\u{00a0}\u{0340}-\u{0341}\u{2000}-\u{200f}\u{2028}-\u{202f}\u{205f}-\u{2063}\u{206a}-\u{206f}\u{2ff0}-\u{2ffb}\u{e000}-\u{f8ff}\u{fdd0}-\u{fdef}\u{fff9}-\u{ffff}\u{1d173}-\u{1d17a}\u{1fffe}-\u{1ffff}\u{2fffe}-\u{2ffff}\u{3fffe}-\u{3ffff}\u{4fffe}-\u{4ffff}\u{5fffe}-\u{5ffff}\u{6fffe}-\u{6ffff}\u{7fffe}-\u{7ffff}\u{8fffe}-\u{8ffff}\u{9fffe}-\u{9ffff}\u{afffe}-\u{affff}\u{bfffe}-\u{bffff}\u{cfffe}-\u{cffff}\u{dfffe}-\u{dffff}\u{e0020}-\u{e007f}\u{efffe}-\u{10ffff}\p{Cs}]/.freeze
  • PROHIBITED_OUTPUT_STORED =

    Matches codepoints prohibited by RFC4013 §2.3 and §2.5.

    See TABLES_PROHIBITED_STORED.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 63 
    Regexp.union(
  UNASSIGNED, PROHIBITED_OUTPUT
).freeze
  • PROHIBITED_STORED =

    Matches strings prohibited by RFC4013 §2.3, §2.4, and §2.5.

    This checks prohibited output, bidirectional characters, and unassigned codepoints.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 93 
    Regexp.union(
  PROHIBITED_OUTPUT_STORED, BIDI_FAILURE,
)
  • TABLES_PROHIBITED =
    RFC4013 §2.3 Prohibited Output
    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 38 
    ["C.1.2", "C.2.1", "C.2.2", "C.3", "C.4", "C.5", "C.6", "C.7", "C.8", "C.9"].freeze
  • TABLES_PROHIBITED_STORED =

    Adds unassigned (by Unicode 3.2) codepoints to TABLES_PROHIBITED.

    RFC4013 §2.5 Unassigned Code Points

    This profile specifies the StringPrep table as its list of unassigned code points.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 45 
    ["A.1", *TABLES_PROHIBITED].freeze
  • UNASSIGNED =
    RFC4013 §2.5 Unassigned Code Points

    This profile specifies the StringPrep table as its list of unassigned code points.

    # File 'lib/net/imap/sasl/saslprep_tables.rb', line 58 
    /\p{^AGE=3.2}/.freeze

Class Method Summary

Class Method Details

.saslprep(str, stored: false, exception: false) (mod_func)

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.

[ GitHub ] 

  


# File 'lib/net/imap/sasl/saslprep.rb', line 31



def saslprep(str, stored: false, exception: false)
  return str if ASCII_NO_CTRLS.match?(str) # raises on incompatible encoding
  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 StringPrep::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