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NAME
itu - standard telecom module
STANDARD TELECOM MODULE
The Standard Telecommodule is an original implementation of various standards managed by the
International Telecommunictaion Union (ITU). At the heart of this module is the Abstract Syntax
Notation(ASN.1) which is widely used to model data records and store certificates.
Abstract syntax notation
The abstract syntax notation (ASN.1) is standardized by the ITU to express a normal form of
communication. The ASN.1 is in fact the de-facto standard for representing X509 certificate and is the
only justification to provide the support for such complex representation.
Encoding rules
This implementation supports all encoding forms as defined by the ITU, namely the Basic Encoding
Rule(BER), the Canonical Encoding Rule(CER) and the Distinguished Encoding Rule(DER). The DER form is by
far the most widely used.
ASN objects
All objects as defined by the ITU are supported in this implementation, including the ability to create
custom OID.
Object Description
AsnBoolean Boolean primitive
AsnInteger Integer primitive
AsnBits Bit string
AsnOctets Octet string
AsnBmp Bmp string
AsnIas IA5 string
AsnNums Numeric string
AsnPrts Printable string
AsnUtfs Unicode string
AsnUnvs Universal string
AsneNull Null primitive
AsneEoc End-of-Content primitive
AsnGtm Generalized time primitive
AsnUtc Utc time primitive
AsnSequence Asn node Sequence
AsnSet Asn node Set
AsnOid Asn object identifier Set
AsnRoid Asn object relative identifier Set
Using ASN.1 objects
Using ASN.1 object is particularly straightfoward. One can directly creates a particular object by
invoking the appropriate constructor.
# create an asn boolean node
trans abn (afnix:itu:AsnBoolean true)
# check the node type
assert true (afnix:itu:asn-node-p abn)
assert true (afnix:itu:asn-boolean-p abn)
Writing the object can be done into a buffer or an output stream. Note that the default encoding is the
DER encoding.
# write into a buffer
trans buf (Buffer)
abn:write buf
# check the buffer content
assert "0101FF" (buf:format)
Building an ASN.1 representation can be achieved by parsing a buffer or an input stream. This is done by
filling a buffer and requesting a buffer node mapping.
# parse the buffer and check
const anb (afnix:itu:AsnBuffer buf)
# map the node to a boolean
trans abn (anb:node-map)
# check the node
assert true (afnix:itu:asn-node-p abn)
assert true (afnix:itu:asn-boolean-p abn)
With more complex structure, it is likely that a sequence object will be returned by the buffer node
mapper. Once the sequence object is created, each node can be accessed by index like any other container.
STANDARD TELECOM REFERENCE
AsnNode
The AsnNodeclass is the base class used to represent the asn tree. The structure of the node is defined
in ITU-T X.690 recommendation. This implementation supports 64 bits tag number with natural machine
length encoding. The Canonical Encoding Rule (CER) and Distinguished Encoding Rule (DER) are defined by
the class. Since ASN.1 provides several encoding schemes, the class is designed to be as generic as
possible but does not provides the mechanism for changing from one representation to another although it
is perfectly valid to read a DER representation and write it in the CER form.
Predicate
asn-node-p
Inheritance
Object
Constants
BER
The BERconstant defines the Basic Encoding Rulenode encoding.
CER
The CERconstant defines the Canonical Encoding Rulenode encoding.
DER
The DERconstant defines the Distinguished Encoding Rulenode encoding.
UNIVERSAL
The UNIVERSALconstant defines the node universal class.
APPLICATION
The APPLICATIONconstant defines the node application class.
CONTEXT-SPECIFIC
The CONTEXT-SPECIFICconstant defines the node context specific class.
PRIVATE
The PRIVATEconstant defines the node private class.
Methods
reset -> none (none)
The resetmethod reset a node to its default value.
length -> Integer (none)
The lengthmethod returns the total node length in bytes.
get-class -> UNIVERSAL|APPLICATION|CONTEXT-SPECIFIC|PRIVATE (none)
The get-classmethod returns the node class.
primitive-p -> Boolean (none)
The primitive-preturns true if the node is a primitive.
constructed-p -> Boolean (none)
The constructed-preturns true if the node is a constructed node.
get-tag-number -> Integer (none)
The get-tag-number-preturns node tag number.
get-content-length -> Integer (none)
The get-content-length-preturns node content length.
write -> none (none|OutputStream|Buffer)
The writemethod write the asn node contents as well as the child nodes to an output stream
argument or a buffer. Without argument, the node is written to the interpreter output stream. With
one argument, the node is written to the specified stream or buffer.
AsnOctets
The AsnOctetsclass is the asn object class that encodes the octet string type. This type can be encoded
either as a primitive or as constructed at sender's option. In CER form, the primitive form is used when
the content length is less than 1000 octets, and the constructed form is used otherwise. The DER form
will always use the primitive form.
Predicate
asn-octets-p
Inheritance
AsnNode
Constructors
AsnOctets (none)
The AsnOctetsconstructor creates a default asn octets string node.
AsnOctets (String|Buffer)
The AsnOctetsconstructor creates an asn octets string node by string of buffer object.
Methods
to-buffer -> Buffer (none)
The to-buffermethod returns a Bufferobject as an octet string representation.
AsnBuffer
The AsnBufferclass is the asn object class that provides a generic implementation of an asn structure.
The class acts as a simple encoder and decoder with special facilities to retarget the buffer content.
Predicate
asn-buffer-p
Inheritance
AsnNode
Constructors
AsnBuffer (none)
The AsnBufferconstructor creates a default asn buffer node.
AsnBuffer (InputStream|Buffer|Bitset)
The AsnBufferconstructor creates an asn buffer node from an input stream, a buffer or a bitset.
Methods
reset -> none (none)
The resetmethod reset the buffer.
parse -> Boolean (InputStream|Buffer|Bitset)
The parsemethod parse a node represented by an input stream, a buffer or a bitset.
node-map -> AsnNode (none)
The node-mapmethod returns a node mapping of this buffer.
get-content-buffer -> Buffer (none)
The get-content-buffermethod returns the asn buffer content as a buffer object.
AsnNull
The AsnNullclass is the asn object class that encodes the null primitive. This primitive has a unique
encoding. The length is always 0 and there is no content octet.
Predicate
asn-null-p
Inheritance
AsnNode
Constructors
AsnNull (none)
The AsnNullconstructor creates a default asn null node.
AsnEoc
The AsnEocclass is the asn object class that encodes the eoc or end-of-content primitive. This primitive
is almost never used but its encoding is used with the indefinite length encoding.
Predicate
asn-eoc-p
Inheritance
AsnNode
Constructors
AsnEoc (none)
The AsnEocconstructor creates a default asn eoc node.
AsnBoolean
The AsnBooleanclass is the asn object class that encodes the boolean primitive. This primitive has a
unique encoding with the CER or DER rule, but the BER rule can support any byte value for the true value.
Predicate
asn-boolean-p
Inheritance
AsnNode
Constructors
AsnBoolean (none)
The AsnBooleanconstructor creates a default asn boolean node.
AsnBoolean (Boolean)
The AsnBooleanconstructor creates an asn boolean node from a boolean object.
Methods
to-boolean -> Boolean (none)
The to-booleanmethod returns a Booleanobject as the asn node representation.
AsnInteger
The AsnIntegerclass is the asn object class that encodes the integer primitive. This primitive has a
unique encoding with the CER or DER rule. All encoding use a signed 2-complement form.
Predicate
asn-integer-p
Inheritance
AsnNode
Constructors
AsnInteger (none)
The AsnIntegerconstructor creates a default asn integer node.
AsnInteger (Integer|Relatif)
The AsnIntegerconstructor creates an asn integer node from an integer or relatif object.
Methods
to-relatif -> Relatif (none)
The to-relatifmethod returns a Relatifobject as the asn node representation.
AsnBits
The AsnBitsclass is the asn object class that encodes the bit string type. This type can be encoded
either as a primitive or as constructed at sender's option. In CER form, the primitive form is used when
the content length is less than 1000 octets, and the constructed form is used otherwise. The DER form
will always use the primitive form.
Predicate
asn-bits-p
Inheritance
AsnNode
Constructors
AsnBits (none)
The AsnBitsconstructor creates a default asn bits node.
AsnBits (String|Bitset)
The AsnBitsconstructor creates an asn bits node from a string or a bitset.
Methods
to-bits -> Bitset (none)
The to-bitsmethod returns a Bitsetobject as a bit string representation.
AsnBmps
The AsnBmpsclass is the asn object class that encodes the asn bmp string primitive also known as the
UCS-2 type string. This string is implemented, after conversion as an octet string. Consequently the
rules for encoding in CER and DER modes are applied.
Predicate
asn-bmps-p
Inheritance
AsnOctets
Constructors
AsnBmps (none)
The AsnBmpsconstructor creates a default asn string (BMP) node.
AsnBmps (String)
The AsnBmpsconstructor creates an asn string (BMP) node from a string.
Methods
to-string -> String (none)
The to-stringmethod returns a Stringobject as a node representation.
AsnIas
The AsnIasclass is the asn object class that encodes the IA5 string primitive. This string is
implemented, after conversion as an octet string. Consequently the rules for encoding in CER and DER
modes are applied.
Predicate
asn-ias-p
Inheritance
AsnOctets
Constructors
AsnIas (none)
The AsnIasconstructor creates a default asn string (IA5) node.
AsnIas (String)
The AsnIasconstructor creates an asn string (IA5) node from a string.
Methods
to-string -> String (none)
The to-stringmethod returns a Stringobject as a node representation.
AsnNums
The AsnNumsclass is the asn object class that encodes the asn numeric string primitive. This string is
implemented, after conversion as an octet string. Consequently the rules for encoding in CER and DER
modes are applied.
Predicate
asn-nums-p
Inheritance
AsnOctets
Constructors
AsnNums (none)
The AsnNumsconstructor creates a default asn string (NUMERIC) node.
AsnNums (String)
The AsnNumsconstructor creates an asn string (NUMERIC) node from a string.
Methods
to-string -> String (none)
The to-stringmethod returns a Stringobject as a node representation.
AsnPrts
The AsnPrtsclass is the asn object class that encodes the asn printable string primitive. This string is
implemented, after conversion as an octet string. Consequently the rules for encoding in CER and DER
modes are applied.
Predicate
asn-prts-p
Inheritance
AsnOctets
Constructors
AsnPrts (none)
The AsnPrtsconstructor creates a default asn string (PRINTABLE) node.
AsnPrts (String)
The AsnPrtsconstructor creates an asn string (PRINTABLE) node from a string.
Methods
to-string -> String (none)
The to-stringmethod returns a Stringobject as a node representation.
AsnUtfs
The AsnUtfsclass is the asn object class that encodes the asn utf string primitive. This string is
implemented as an octet string. Consequently the rules for encoding in CER and DER modes are applied.
Predicate
asn-utfs-p
Inheritance
AsnOctets
Constructors
AsnUtfs (none)
The AsnUtfsconstructor creates a default asn string (UNICODE) node.
AsnUtfs (String)
The AsnUtfsconstructor creates an asn string (UNICODE) node from a string.
Methods
to-string -> String (none)
The to-stringmethod returns a Stringobject as a node representation.
AsnUnvs
The AsnUnvsclass is the asn object class that encodes the universal string primitive also known as the
UCS-4 type string. This string is implemented, after conversion as an octet string. Consequently the
rules for encoding in CER and DER modes are applied.
Predicate
asn-unvs-p
Inheritance
AsnOctets
Constructors
AsnUnvs (none)
The AsnUnvsconstructor creates a default asn string (UNIVERSAL) node.
AsnUnvs (String)
The AsnUnvsconstructor creates an asn string (UNIVERSAL) node from a string.
Methods
to-string -> String (none)
The to-stringmethod returns a Stringobject as a node representation.
AsnGtm
The AsnGtmclass is the asn object class that encodes the generalized time primitive. This primitive is
encoded from its equivalent string representation. Although, the constructed mode is authorized, it does
not make that much sense to use it.
Predicate
asn-gtm-p
Inheritance
AsnNode
Constructors
AsnGtm (none)
The AsnGtmconstructor creates a default asn gtm node.
AsnGtm (String)
The AsnGtmconstructor creates an asn gtm node from a string.
Methods
utc-p -> Boolean (none)
The utc-ppredicate returns true if the time is expressed in UTC mode.
to-time -> Integer (none)
The to-timemethod returns a time representation of this asn node.
to-string -> String (none)
The to-stringmethod returns a string representation of this asn node.
AsnUtc
The AsnUtcclass is the asn object class that encodes the utc time primitive. This primitive is encoding
from its equivalent string representation. Although, the constructed mode is authorized, it does not make
that much sense to use it.
Predicate
asn-utc-p
Inheritance
AsnNode
Constructors
AsnUtc (none)
The AsnUtcconstructor creates a default asn utc node.
AsnUtc (String)
The AsnUtcconstructor creates an asn utc node from a string.
Methods
utc-p -> Boolean (none)
The utc-ppredicate returns true if the time is expressed in UTC mode.
to-time -> Integer (none)
The to-timemethod returns a time representation of this asn node.
to-string -> String (none)
The to-stringmethod returns a string representation of this asn node.
AsnSequence
The AsnSequenceclass is the asn object class that encodes the sequence constructed type. The order of
elements is preserved in the encoding of the sequence.
Predicate
asn-sequence-p
Inheritance
AsnNode
Constructors
AsnSequence (none)
The AsnSequenceconstructor creates an empty asn sequence node.
Methods
node-length -> Integer (none)
The node-lengthmethod returns the number of nodes in the sequence.
node-add -> none (AsnNode)
The node-addmethod adds a node to the sequence.
node-get -> AsnNode (Integer)
The node-getmethod returns an asn node by index.
AsnSet
The AsnSetclass is the asn object class that encodes the set constructed type. The order of elements is
not important in a set.
Predicate
asn-set-p
Inheritance
AsnNode
Constructors
AsnSet (none)
The AsnSetconstructor creates an empty asn set node.
Methods
node-length -> Integer (none)
The node-lengthmethod returns the number of nodes in the set.
node-add -> none (AsnNode)
The node-addmethod adds a node to the set.
node-get -> AsnNode (Integer)
The node-getmethod returns an asn node by index.
Oid
The Oidclass is a base class that represents the X500 object identifier which is used in the ASN.1
encoding and in the X509 standard. An oid is simply represented by a vector of subidentifiers.
Predicate
oid-p
Inheritance
Object
Constructors
Oid (Integer|...)
The Oidconstructor creates an oid from a sequence of integers.
Methods
reset -> none (none)
The resetmethod resets the oid object to its null empty state.
length -> Integer (none)
The lengthmethod returns the length of the oid.
add -> none (Integer|...)
The addmethod adds one or more sub-indentifiers to the oid.
get -> Integer (Integer)
The getmethod returns an oid sub-identifier by index.
format -> String (none)
The formatmethod returns a string representation of the oid.
AsnOid
The AsnOidclass is the asn object class that encodes the object identifier primitive. This primitive has
a unique encoding with the CER or DER rule. The oid is built as a vector of subidentifiers (sid). Each
sid is represented as an octa (64 bits) value.
Predicate
asn-oid-p
Inheritance
AsnNode
Constructors
AsnOid (Integer|...)
The AsnOidconstructor creates an asn oid from a sequence of sid.
Methods
sid-length -> Integer (none)
The lengthmethod returns the length of the oid.
sid-add -> none (Integer)
The sid-addmethod adds a sid the oid object.
sid-get -> Integer (Integer)
The sid-getmethod returns a sid by oid index.
get-oid -> Oid (none)
The get-oidmethod returns an oid object as the asn oid representation.
AsnRoid
The AsnRoidclass is the asn object class that encodes the object relative identifier primitive. This
primitive has a unique encoding with the CER or DER rule. The oid is built as a vector of subidentifiers
(sid). Each sid is represented as an octa (64 bits) value. The difference with the oid object is to be
found in the encoding of the first 2 sid.
Predicate
asn-roid-p
Inheritance
AsnNode
Constructors
AsnRoid (Integer|...)
The AsnRoidconstructor creates an asn roid from a sequence of sid.
Methods
sid-length -> Integer (none)
The lengthmethod returns the length of the oid.
sid-add -> none (Integer)
The sid-addmethod adds a sid the oid object.
sid-get -> Integer (Integer)
The sid-getmethod returns a sid by oid index.
get-oid -> Oid (none)
The get-oidmethod returns an oid object as the asn oid representation.
Functions
asn-random-bits -> none (Integer)
The exitfunction creates a random asn bit string. The argument is the number of bits in the random
string.
asn-random-octets -> none (Integer)
The exitfunction creates a random asn octet string. The integer argument is the number of octets
in the string.
AFNIX 2017-11-22 itu(3)