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Diffstat (limited to 'vendor/gems/net-ldap-0.2.2/lib/net/ber.rb')
| -rw-r--r-- | vendor/gems/net-ldap-0.2.2/lib/net/ber.rb | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/vendor/gems/net-ldap-0.2.2/lib/net/ber.rb b/vendor/gems/net-ldap-0.2.2/lib/net/ber.rb new file mode 100644 index 000000000..d65a354e9 --- /dev/null +++ b/vendor/gems/net-ldap-0.2.2/lib/net/ber.rb @@ -0,0 +1,316 @@ +# -*- ruby encoding: utf-8 -*- +module Net # :nodoc: + ## + # == Basic Encoding Rules (BER) Support Module + # + # Much of the text below is cribbed from Wikipedia: + # http://en.wikipedia.org/wiki/Basic_Encoding_Rules + # + # The ITU Specification is also worthwhile reading: + # http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf + # + # The Basic Encoding Rules were the original rules laid out by the ASN.1 + # standard for encoding abstract information into a concrete data stream. + # The rules, collectively referred to as a transfer syntax in ASN.1 + # parlance, specify the exact octet sequences which are used to encode a + # given data item. The syntax defines such elements as: the + # representations for basic data types, the structure of length + # information, and the means for defining complex or compound types based + # on more primitive types. The BER syntax, along with two subsets of BER + # (the Canonical Encoding Rules and the Distinguished Encoding Rules), are + # defined by the ITU-T's X.690 standards document, which is part of the + # ASN.1 document series. + # + # == Encoding + # The BER format specifies a self-describing and self-delimiting format + # for encoding ASN.1 data structures. Each data element is encoded as a + # type identifier, a length description, the actual data elements, and + # where necessary, an end-of-content marker. This format allows a receiver + # to decode the ASN.1 information from an incomplete stream, without + # requiring any pre-knowledge of the size, content, or semantic meaning of + # the data. + # + # <Type | Length | Value [| End-of-Content]> + # + # == Protocol Data Units (PDU) + # Protocols are defined with schema represented in BER, such that a PDU + # consists of cascaded type-length-value encodings. + # + # === Type Tags + # BER type tags are represented as single octets (bytes). The lower five + # bits of the octet are tag identifier numbers and the upper three bits of + # the octet are used to distinguish the type as native to ASN.1, + # application-specific, context-specific, or private. See + # Net::BER::TAG_CLASS and Net::BER::ENCODING_TYPE for more information. + # + # If Class is set to Universal (0b00______), the value is of a type native + # to ASN.1 (e.g. INTEGER). The Application class (0b01______) is only + # valid for one specific application. Context_specific (0b10______) + # depends on the context and private (0b11_______) can be defined in + # private specifications + # + # If the primitive/constructed bit is zero (0b__0_____), it specifies that + # the value is primitive like an INTEGER. If it is one (0b__1_____), the + # value is a constructed value that contains type-length-value encoded + # types like a SET or a SEQUENCE. + # + # === Defined Universal (ASN.1 Native) Types + # There are a number of pre-defined universal (native) types. + # + # <table> + # <tr><th>Name</th><th>Primitive<br />Constructed</th><th>Number</th></tr> + # <tr><th>EOC (End-of-Content)</th><th>P</th><td>0: 0 (0x0, 0b00000000)</td></tr> + # <tr><th>BOOLEAN</th><th>P</th><td>1: 1 (0x01, 0b00000001)</td></tr> + # <tr><th>INTEGER</th><th>P</th><td>2: 2 (0x02, 0b00000010)</td></tr> + # <tr><th>BIT STRING</th><th>P</th><td>3: 3 (0x03, 0b00000011)</td></tr> + # <tr><th>BIT STRING</th><th>C</th><td>3: 35 (0x23, 0b00100011)</td></tr> + # <tr><th>OCTET STRING</th><th>P</th><td>4: 4 (0x04, 0b00000100)</td></tr> + # <tr><th>OCTET STRING</th><th>C</th><td>4: 36 (0x24, 0b00100100)</td></tr> + # <tr><th>NULL</th><th>P</th><td>5: 5 (0x05, 0b00000101)</td></tr> + # <tr><th>OBJECT IDENTIFIER</th><th>P</th><td>6: 6 (0x06, 0b00000110)</td></tr> + # <tr><th>Object Descriptor</th><th>P</th><td>7: 7 (0x07, 0b00000111)</td></tr> + # <tr><th>EXTERNAL</th><th>C</th><td>8: 40 (0x28, 0b00101000)</td></tr> + # <tr><th>REAL (float)</th><th>P</th><td>9: 9 (0x09, 0b00001001)</td></tr> + # <tr><th>ENUMERATED</th><th>P</th><td>10: 10 (0x0a, 0b00001010)</td></tr> + # <tr><th>EMBEDDED PDV</th><th>C</th><td>11: 43 (0x2b, 0b00101011)</td></tr> + # <tr><th>UTF8String</th><th>P</th><td>12: 12 (0x0c, 0b00001100)</td></tr> + # <tr><th>UTF8String</th><th>C</th><td>12: 44 (0x2c, 0b00101100)</td></tr> + # <tr><th>RELATIVE-OID</th><th>P</th><td>13: 13 (0x0d, 0b00001101)</td></tr> + # <tr><th>SEQUENCE and SEQUENCE OF</th><th>C</th><td>16: 48 (0x30, 0b00110000)</td></tr> + # <tr><th>SET and SET OF</th><th>C</th><td>17: 49 (0x31, 0b00110001)</td></tr> + # <tr><th>NumericString</th><th>P</th><td>18: 18 (0x12, 0b00010010)</td></tr> + # <tr><th>NumericString</th><th>C</th><td>18: 50 (0x32, 0b00110010)</td></tr> + # <tr><th>PrintableString</th><th>P</th><td>19: 19 (0x13, 0b00010011)</td></tr> + # <tr><th>PrintableString</th><th>C</th><td>19: 51 (0x33, 0b00110011)</td></tr> + # <tr><th>T61String</th><th>P</th><td>20: 20 (0x14, 0b00010100)</td></tr> + # <tr><th>T61String</th><th>C</th><td>20: 52 (0x34, 0b00110100)</td></tr> + # <tr><th>VideotexString</th><th>P</th><td>21: 21 (0x15, 0b00010101)</td></tr> + # <tr><th>VideotexString</th><th>C</th><td>21: 53 (0x35, 0b00110101)</td></tr> + # <tr><th>IA5String</th><th>P</th><td>22: 22 (0x16, 0b00010110)</td></tr> + # <tr><th>IA5String</th><th>C</th><td>22: 54 (0x36, 0b00110110)</td></tr> + # <tr><th>UTCTime</th><th>P</th><td>23: 23 (0x17, 0b00010111)</td></tr> + # <tr><th>UTCTime</th><th>C</th><td>23: 55 (0x37, 0b00110111)</td></tr> + # <tr><th>GeneralizedTime</th><th>P</th><td>24: 24 (0x18, 0b00011000)</td></tr> + # <tr><th>GeneralizedTime</th><th>C</th><td>24: 56 (0x38, 0b00111000)</td></tr> + # <tr><th>GraphicString</th><th>P</th><td>25: 25 (0x19, 0b00011001)</td></tr> + # <tr><th>GraphicString</th><th>C</th><td>25: 57 (0x39, 0b00111001)</td></tr> + # <tr><th>VisibleString</th><th>P</th><td>26: 26 (0x1a, 0b00011010)</td></tr> + # <tr><th>VisibleString</th><th>C</th><td>26: 58 (0x3a, 0b00111010)</td></tr> + # <tr><th>GeneralString</th><th>P</th><td>27: 27 (0x1b, 0b00011011)</td></tr> + # <tr><th>GeneralString</th><th>C</th><td>27: 59 (0x3b, 0b00111011)</td></tr> + # <tr><th>UniversalString</th><th>P</th><td>28: 28 (0x1c, 0b00011100)</td></tr> + # <tr><th>UniversalString</th><th>C</th><td>28: 60 (0x3c, 0b00111100)</td></tr> + # <tr><th>CHARACTER STRING</th><th>P</th><td>29: 29 (0x1d, 0b00011101)</td></tr> + # <tr><th>CHARACTER STRING</th><th>C</th><td>29: 61 (0x3d, 0b00111101)</td></tr> + # <tr><th>BMPString</th><th>P</th><td>30: 30 (0x1e, 0b00011110)</td></tr> + # <tr><th>BMPString</th><th>C</th><td>30: 62 (0x3e, 0b00111110)</td></tr> + # </table> + module BER + VERSION = '0.2.2' + + ## + # Used for BER-encoding the length and content bytes of a Fixnum integer + # values. + MAX_FIXNUM_SIZE = 0.size + + ## + # BER tag classes are kept in bits seven and eight of the tag type + # octet. + # + # <table> + # <tr><th>Bitmask</th><th>Definition</th></tr> + # <tr><th><tt>0b00______</tt></th><td>Universal (ASN.1 Native) Types</td></tr> + # <tr><th><tt>0b01______</tt></th><td>Application Types</td></tr> + # <tr><th><tt>0b10______</tt></th><td>Context-Specific Types</td></tr> + # <tr><th><tt>0b11______</tt></th><td>Private Types</td></tr> + # </table> + TAG_CLASS = { + :universal => 0b00000000, # 0 + :application => 0b01000000, # 64 + :context_specific => 0b10000000, # 128 + :private => 0b11000000, # 192 + } + + ## + # BER encoding type is kept in bit 6 of the tag type octet. + # + # <table> + # <tr><th>Bitmask</th><th>Definition</th></tr> + # <tr><th><tt>0b__0_____</tt></th><td>Primitive</td></tr> + # <tr><th><tt>0b__1_____</tt></th><td>Constructed</td></tr> + # </table> + ENCODING_TYPE = { + :primitive => 0b00000000, # 0 + :constructed => 0b00100000, # 32 + } + + ## + # Accepts a hash of hashes describing a BER syntax and converts it into + # a byte-keyed object for fast BER conversion lookup. The resulting + # "compiled" syntax is used by Net::BER::BERParser. + # + # This method should be called only by client classes of Net::BER (e.g., + # Net::LDAP and Net::SNMP) and not by clients of those classes. + # + # The hash-based syntax uses TAG_CLASS keys that contain hashes of + # ENCODING_TYPE keys that contain tag numbers with object type markers. + # + # :<TAG_CLASS> => { + # :<ENCODING_TYPE> => { + # <number> => <object-type> + # }, + # }, + # + # === Permitted Object Types + # <tt>:string</tt>:: A string value, represented as BerIdentifiedString. + # <tt>:integer</tt>:: An integer value, represented with Fixnum. + # <tt>:oid</tt>:: An Object Identifier value; see X.690 section + # 8.19. Currently represented with a standard array, + # but may be better represented as a + # BerIdentifiedOID object. + # <tt>:array</tt>:: A sequence, represented as BerIdentifiedArray. + # <tt>:boolean</tt>:: A boolean value, represented as +true+ or +false+. + # <tt>:null</tt>:: A null value, represented as BerIdentifiedNull. + # + # === Example + # Net::LDAP defines its ASN.1 BER syntax something like this: + # + # class Net::LDAP + # AsnSyntax = Net::BER.compile_syntax({ + # :application => { + # :primitive => { + # 2 => :null, + # }, + # :constructed => { + # 0 => :array, + # # ... + # }, + # }, + # :context_specific => { + # :primitive => { + # 0 => :string, + # # ... + # }, + # :constructed => { + # 0 => :array, + # # ... + # }, + # } + # }) + # end + # + # NOTE:: For readability and formatting purposes, Net::LDAP and its + # siblings actually construct their syntaxes more deliberately, + # as shown below. Since a hash is passed in the end in any case, + # the format does not matter. + # + # primitive = { 2 => :null } + # constructed = { + # 0 => :array, + # # ... + # } + # application = { + # :primitive => primitive, + # :constructed => constructed + # } + # + # primitive = { + # 0 => :string, + # # ... + # } + # constructed = { + # 0 => :array, + # # ... + # } + # context_specific = { + # :primitive => primitive, + # :constructed => constructed + # } + # AsnSyntax = Net::BER.compile_syntax(:application => application, + # :context_specific => context_specific) + def self.compile_syntax(syntax) + # TODO 20100327 AZ: Should we be allocating an array of 256 values + # that will either be +nil+ or an object type symbol, or should we + # allocate an empty Hash since unknown values return +nil+ anyway? + out = [ nil ] * 256 + syntax.each do |tag_class_id, encodings| + tag_class = TAG_CLASS[tag_class_id] + encodings.each do |encoding_id, classes| + encoding = ENCODING_TYPE[encoding_id] + object_class = tag_class + encoding + classes.each do |number, object_type| + out[object_class + number] = object_type + end + end + end + out + end + end +end + +class Net::BER::BerError < RuntimeError; end + +## +# An Array object with a BER identifier attached. +class Net::BER::BerIdentifiedArray < Array + attr_accessor :ber_identifier + + def initialize(*args) + super + end +end + +## +# A BER object identifier. +class Net::BER::BerIdentifiedOid + attr_accessor :ber_identifier + + def initialize(oid) + if oid.is_a?(String) + oid = oid.split(/\./).map {|s| s.to_i } + end + @value = oid + end + + def to_ber + to_ber_oid + end + + def to_ber_oid + @value.to_ber_oid + end + + def to_s + @value.join(".") + end + + def to_arr + @value.dup + end +end + +## +# A String object with a BER identifier attached. +class Net::BER::BerIdentifiedString < String + attr_accessor :ber_identifier + def initialize args + super args + end +end + +module Net::BER + ## + # A BER null object. + class BerIdentifiedNull + attr_accessor :ber_identifier + def to_ber + "\005\000" + end + end + + ## + # The default BerIdentifiedNull object. + Null = Net::BER::BerIdentifiedNull.new +end + +require 'net/ber/core_ext' |