different layout
git-svn-id: https://asn1c.svn.sourceforge.net/svnroot/asn1c/trunk@684 59561ff5-6e30-0410-9f3c-9617f08c8826
diff --git a/doc/asn1c-usage.html b/doc/asn1c-usage.html
index 2a9f796..c2e3377 100644
--- a/doc/asn1c-usage.html
+++ b/doc/asn1c-usage.html
@@ -41,110 +41,110 @@
<!--Table of Contents-->
<UL>
+<LI><A NAME="tex2html51"
+ HREF="asn1c-usage.html#SECTION02000000000000000000">Using the ASN.1 Compiler</A>
+<UL>
+<LI><A NAME="tex2html52"
+ HREF="asn1c-usage.html#SECTION02100000000000000000">Introduction to the ASN.1 Compiler</A>
+<UL>
<LI><A NAME="tex2html53"
- HREF="asn1c-usage.html#SECTION02000000000000000000">ASN.1 Basics</A>
-<UL>
+ HREF="asn1c-usage.html#SECTION02110000000000000000">Quick start with asn1c</A>
<LI><A NAME="tex2html54"
- HREF="asn1c-usage.html#SECTION02100000000000000000">Abstract Syntax Notation: ASN.1</A>
-<UL>
+ HREF="asn1c-usage.html#SECTION02120000000000000000">Recognizing compiler output</A>
<LI><A NAME="tex2html55"
- HREF="asn1c-usage.html#SECTION02110000000000000000">Some of the ASN.1 Basic Types</A>
-<UL>
-<LI><A NAME="tex2html56"
- HREF="asn1c-usage.html#SECTION02111000000000000000">The BOOLEAN type</A>
-<LI><A NAME="tex2html57"
- HREF="asn1c-usage.html#SECTION02112000000000000000">The INTEGER type</A>
-<LI><A NAME="tex2html58"
- HREF="asn1c-usage.html#SECTION02113000000000000000">The ENUMERATED type</A>
-<LI><A NAME="tex2html59"
- HREF="asn1c-usage.html#SECTION02114000000000000000">The OCTET STRING type</A>
-<LI><A NAME="tex2html60"
- HREF="asn1c-usage.html#SECTION02115000000000000000">The OBJECT IDENTIFIER type</A>
-<LI><A NAME="tex2html61"
- HREF="asn1c-usage.html#SECTION02116000000000000000">The RELATIVE-OID type</A>
+ HREF="asn1c-usage.html#SECTION02130000000000000000">Command line options</A>
</UL>
-<LI><A NAME="tex2html62"
- HREF="asn1c-usage.html#SECTION02120000000000000000">Some of the ASN.1 String Types</A>
+<LI><A NAME="tex2html56"
+ HREF="asn1c-usage.html#SECTION02200000000000000000">Using the ASN.1 Compiler</A>
<UL>
+<LI><A NAME="tex2html57"
+ HREF="asn1c-usage.html#SECTION02210000000000000000">Invoking the ASN.1 helper code</A>
+<UL>
+<LI><A NAME="tex2html58"
+ HREF="asn1c-usage.html#SECTION02211000000000000000">Decoding BER</A>
+<LI><A NAME="tex2html59"
+ HREF="asn1c-usage.html#SECTION02212000000000000000">Encoding DER</A>
+<LI><A NAME="tex2html60"
+ HREF="asn1c-usage.html#SECTION02213000000000000000">Encoding XER</A>
+<LI><A NAME="tex2html61"
+ HREF="asn1c-usage.html#SECTION02214000000000000000">Decoding XER</A>
+<LI><A NAME="tex2html62"
+ HREF="asn1c-usage.html#SECTION02215000000000000000">Validating the target structure</A>
<LI><A NAME="tex2html63"
- HREF="asn1c-usage.html#SECTION02121000000000000000">The IA5String type</A>
+ HREF="asn1c-usage.html#SECTION02216000000000000000">Printing the target structure</A>
<LI><A NAME="tex2html64"
- HREF="asn1c-usage.html#SECTION02122000000000000000">The UTF8String type</A>
+ HREF="asn1c-usage.html#SECTION02217000000000000000">Freeing the target structure</A>
+</UL>
+</UL>
<LI><A NAME="tex2html65"
- HREF="asn1c-usage.html#SECTION02123000000000000000">The NumericString type</A>
+ HREF="asn1c-usage.html#SECTION02300000000000000000">Step by step examples</A>
+<UL>
<LI><A NAME="tex2html66"
- HREF="asn1c-usage.html#SECTION02124000000000000000">The PrintableString type</A>
+ HREF="asn1c-usage.html#SECTION02310000000000000000">A ''Rectangle'' Encoder</A>
<LI><A NAME="tex2html67"
- HREF="asn1c-usage.html#SECTION02125000000000000000">The VisibleString type</A>
+ HREF="asn1c-usage.html#SECTION02320000000000000000">A ''Rectangle'' Decoder</A>
</UL>
<LI><A NAME="tex2html68"
- HREF="asn1c-usage.html#SECTION02130000000000000000">ASN.1 Constructed Types</A>
+ HREF="asn1c-usage.html#SECTION02400000000000000000">Constraint validation examples</A>
<UL>
<LI><A NAME="tex2html69"
- HREF="asn1c-usage.html#SECTION02131000000000000000">The SEQUENCE type</A>
+ HREF="asn1c-usage.html#SECTION02410000000000000000">Adding constraints into ''Rectangle'' type</A>
+</UL>
+</UL><BR>
<LI><A NAME="tex2html70"
- HREF="asn1c-usage.html#SECTION02132000000000000000">The SET type</A>
+ HREF="asn1c-usage.html#SECTION03000000000000000000">ASN.1 Basics</A>
+<UL>
<LI><A NAME="tex2html71"
- HREF="asn1c-usage.html#SECTION02133000000000000000">The CHOICE type</A>
+ HREF="asn1c-usage.html#SECTION03100000000000000000">Abstract Syntax Notation: ASN.1</A>
+<UL>
<LI><A NAME="tex2html72"
- HREF="asn1c-usage.html#SECTION02134000000000000000">The SEQUENCE OF type</A>
+ HREF="asn1c-usage.html#SECTION03110000000000000000">Some of the ASN.1 Basic Types</A>
+<UL>
<LI><A NAME="tex2html73"
- HREF="asn1c-usage.html#SECTION02135000000000000000">The SET OF type</A>
-</UL>
-</UL>
-</UL><BR>
+ HREF="asn1c-usage.html#SECTION03111000000000000000">The BOOLEAN type</A>
<LI><A NAME="tex2html74"
- HREF="asn1c-usage.html#SECTION03000000000000000000">Using the ASN.1 Compiler</A>
-<UL>
+ HREF="asn1c-usage.html#SECTION03112000000000000000">The INTEGER type</A>
<LI><A NAME="tex2html75"
- HREF="asn1c-usage.html#SECTION03100000000000000000">Introduction to the ASN.1 Compiler</A>
+ HREF="asn1c-usage.html#SECTION03113000000000000000">The ENUMERATED type</A>
<LI><A NAME="tex2html76"
- HREF="asn1c-usage.html#SECTION03200000000000000000">Quick start</A>
+ HREF="asn1c-usage.html#SECTION03114000000000000000">The OCTET STRING type</A>
<LI><A NAME="tex2html77"
- HREF="asn1c-usage.html#SECTION03300000000000000000">Using the ASN.1 Compiler</A>
-<UL>
+ HREF="asn1c-usage.html#SECTION03115000000000000000">The OBJECT IDENTIFIER type</A>
<LI><A NAME="tex2html78"
- HREF="asn1c-usage.html#SECTION03310000000000000000">Command-line options</A>
+ HREF="asn1c-usage.html#SECTION03116000000000000000">The RELATIVE-OID type</A>
+</UL>
<LI><A NAME="tex2html79"
- HREF="asn1c-usage.html#SECTION03320000000000000000">Recognizing compiler output</A>
+ HREF="asn1c-usage.html#SECTION03120000000000000000">Some of the ASN.1 String Types</A>
+<UL>
<LI><A NAME="tex2html80"
- HREF="asn1c-usage.html#SECTION03330000000000000000">Invoking the ASN.1 helper code from an application</A>
-<UL>
+ HREF="asn1c-usage.html#SECTION03121000000000000000">The IA5String type</A>
<LI><A NAME="tex2html81"
- HREF="asn1c-usage.html#SECTION03331000000000000000">Decoding BER</A>
+ HREF="asn1c-usage.html#SECTION03122000000000000000">The UTF8String type</A>
<LI><A NAME="tex2html82"
- HREF="asn1c-usage.html#SECTION03332000000000000000">Encoding DER</A>
+ HREF="asn1c-usage.html#SECTION03123000000000000000">The NumericString type</A>
<LI><A NAME="tex2html83"
- HREF="asn1c-usage.html#SECTION03333000000000000000">Encoding XER</A>
+ HREF="asn1c-usage.html#SECTION03124000000000000000">The PrintableString type</A>
<LI><A NAME="tex2html84"
- HREF="asn1c-usage.html#SECTION03334000000000000000">Validating the target structure</A>
+ HREF="asn1c-usage.html#SECTION03125000000000000000">The VisibleString type</A>
+</UL>
<LI><A NAME="tex2html85"
- HREF="asn1c-usage.html#SECTION03335000000000000000">Printing the target structure</A>
+ HREF="asn1c-usage.html#SECTION03130000000000000000">ASN.1 Constructed Types</A>
+<UL>
<LI><A NAME="tex2html86"
- HREF="asn1c-usage.html#SECTION03336000000000000000">Freeing the target structure</A>
-</UL>
-</UL>
-</UL><BR>
+ HREF="asn1c-usage.html#SECTION03131000000000000000">The SEQUENCE type</A>
<LI><A NAME="tex2html87"
- HREF="asn1c-usage.html#SECTION04000000000000000000">Examples</A>
-<UL>
+ HREF="asn1c-usage.html#SECTION03132000000000000000">The SET type</A>
<LI><A NAME="tex2html88"
- HREF="asn1c-usage.html#SECTION04100000000000000000">Step by step examples</A>
-<UL>
+ HREF="asn1c-usage.html#SECTION03133000000000000000">The CHOICE type</A>
<LI><A NAME="tex2html89"
- HREF="asn1c-usage.html#SECTION04110000000000000000">A ''Rectangle'' Encoder</A>
+ HREF="asn1c-usage.html#SECTION03134000000000000000">The SEQUENCE OF type</A>
<LI><A NAME="tex2html90"
- HREF="asn1c-usage.html#SECTION04120000000000000000">A ''Rectangle'' Decoder</A>
+ HREF="asn1c-usage.html#SECTION03135000000000000000">The SET OF type</A>
</UL>
-<LI><A NAME="tex2html91"
- HREF="asn1c-usage.html#SECTION04200000000000000000">Constraint validation examples</A>
-<UL>
-<LI><A NAME="tex2html92"
- HREF="asn1c-usage.html#SECTION04210000000000000000">Adding constraints into ''Rectangle'' type</A>
</UL>
</UL><BR>
-<LI><A NAME="tex2html93"
- HREF="asn1c-usage.html#SECTION05000000000000000000">Bibliography</A>
+<LI><A NAME="tex2html91"
+ HREF="asn1c-usage.html#SECTION04000000000000000000">Bibliography</A>
</UL>
<!--End of Table of Contents-->
@@ -153,82 +153,38 @@
<P>
<H1><A NAME="SECTION02000000000000000000">
-ASN.1 Basics</A>
+Using the ASN.1 Compiler</A>
</H1>
<P>
<H1><A NAME="SECTION02100000000000000000">
-Abstract Syntax Notation: ASN.1</A>
+Introduction to the ASN.1 Compiler</A>
</H1>
<P>
-<I>This chapter defines some basic ASN.1 concepts and describes
-several most widely used types. It is by no means an authoritative
-or complete reference. For more complete ASN.1 description, please
-refer to Olivier Dubuisson's book [<A
- HREF="asn1c-usage.html#Dub00">Dub00</A>] or the ASN.1 body
-of standards itself [<A
- HREF="asn1c-usage.html#ITU-T_ASN.1">ITU-T/ASN.1</A>].</I>
+The purpose of the ASN.1 compiler, of which this document is part,
+is to convert the specifications in ASN.1 notation into some other
+language. At this moment, only C and C++ target languages are supported,
+the latter is in upward compatibility mode.
<P>
-The Abstract Syntax Notation One is used to formally describe the
-semantics of data transmitted across the network. Two communicating
-parties may have different formats of their native data types (i.e.
-number of bits in the integer type), thus it is important to have
-a way to describe the data in a manner which is independent from the
-particular machine's representation. The ASN.1 specifications are
-used to achieve the following:
+The compiler reads the specification and emits a series of target
+language structures (C's structs, unions, enums) describing the corresponding
+ASN.1 types. The compiler also creates the code which allows automatic
+serialization and deserialization of these structures using several
+standardized encoding rules (BER, DER, XER).
<P>
-
-<UL>
-<LI>The specification expressed in the ASN.1 notation is a formal and
-precise way to communicate the data semantics to human readers;
-</LI>
-<LI>The ASN.1 specifications may be used as input for automatic compilers
-which produce the code for some target language (C, C++, Java, etc)
-to encode and decode the data according to some encoding rules (which
-are also defined by the ASN.1 standard).
-</LI>
-</UL>
-Consider the following example:
+For example, suppose the following ASN.1 module is given<A NAME="tex2html1"
+ HREF="#foot818"><SUP>1.1</SUP></A>:
<P>
<BLOCKQUOTE><PRE>
-Rectangle ::= SEQUENCE {
- height INTEGER,
- width INTEGER
-}
-</PRE>
-</BLOCKQUOTE>
-This ASN.1 specification describes a constructed type, <I>Rectangle</I>,
-containing two integer fields. This specification may tell the reader
-that there exists this kind of data structure and that some entity
-may be prepared to send or receive it. The question on <I>how</I>
-that entity is going to send or receive the <I>encoded data</I> is
-outside the scope of ASN.1. For example, this data structure may be
-encoded according to some encoding rules and sent to the destination
-using the TCP protocol. The ASN.1 specifies several ways of encoding
-(or ''serializing'', or ''marshaling'') the data: BER, CER, DER
-and XER, some of them which will be outlined later.
-
-<P>
-The complete specification must be wrapped in a module, which looks
-like this:
-
-<P>
-
-<BLOCKQUOTE><PRE>
-RectangleModule1
- { iso org(3) dod(6) internet(1) private(4)
- enterprise(1) spelio(9363) software(1)
- asn1c(5) docs(2) rectangle(1) 1 }
- DEFINITIONS AUTOMATIC TAGS ::=
+RectangleTest DEFINITIONS ::=
BEGIN
--- This is a comment which describes nothing.
Rectangle ::= SEQUENCE {
height INTEGER, -- Height of the rectangle
width INTEGER -- Width of the rectangle
@@ -237,356 +193,9 @@
END
</PRE>
</BLOCKQUOTE>
-The module header consists of module name (RectangleModule1), the
-module object identifier ({...}), a keyword ''DEFINITIONS'', a
-set of module flags (AUTOMATIC TAGS) and ''::= BEGIN''. The module
-ends with an ''END'' statement.
-
-<P>
-
-<H1><A NAME="SECTION02110000000000000000">
-Some of the ASN.1 Basic Types</A>
-</H1>
-
-<P>
-
-<H2><A NAME="SECTION02111000000000000000">
-The BOOLEAN type</A>
-</H2>
-
-<P>
-The BOOLEAN type models the simple binary TRUE/FALSE, YES/NO, ON/OFF
-or a similar kind of two-way choice.
-
-<P>
-
-<H2><A NAME="SECTION02112000000000000000">
-The INTEGER type</A>
-</H2>
-
-<P>
-The INTEGER type is a signed natural number type without any restrictions
-on its size. If the automatic checking on INTEGER value bounds are
-necessary, the subtype constraints must be used.
-
-<P>
-
-<BLOCKQUOTE><PRE>
-SimpleInteger ::= INTEGER
-
--- An integer with a very limited range
-SmallPositiveInt ::= INTEGER (0..127)
-
--- Integer, negative
-NegativeInt ::= INTEGER (MIN..0)
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H2><A NAME="SECTION02113000000000000000">
-The ENUMERATED type</A>
-</H2>
-
-<P>
-The ENUMERATED type is semantically equivalent to the INTEGER type
-with some integer values explicitly named.
-
-<P>
-
-<BLOCKQUOTE><PRE>
-FruitId ::= ENUMERATED { apple(1), orange(2) }
-
--- The numbers in braces are optional,
--- the enumeration can be performed
--- automatically by the compiler
-ComputerOSType ::= ENUMERATED {
- FreeBSD, -- acquires value 0
- Windows, -- acquires value 1
- Solaris(5), -- remains 5
- Linux, -- becomes 6
- MacOS -- becomes 7
-}
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H2><A NAME="SECTION02114000000000000000">
-The OCTET STRING type</A>
-</H2>
-
-<P>
-This type models the sequence of 8-bit bytes. This may be used to
-transmit some opaque data or data serialized by other types of encoders
-(i.e. video file, photo picture, etc).
-
-<P>
-
-<H2><A NAME="SECTION02115000000000000000">
-The OBJECT IDENTIFIER type</A>
-</H2>
-
-<P>
-The OBJECT IDENTIFIER is used to represent the unique identifier of
-any object, starting from the very root of the registration tree.
-If your organization needs to uniquely identify something (a router,
-a room, a person, a standard, or whatever), you are encouraged to
-get your own identification subtree at <A HREF=http://www.iana.org/protocols/forms.htm>http://www.iana.org/protocols/forms.htm</A>.
-
-<P>
-For example, the very first ASN.1 module in this document has the
-following OBJECT IDENTIFIER: 1 3 6 1 4 1 9363 1 5 2 1 1.
-
-<P>
-
-<BLOCKQUOTE><PRE>
-ExampleOID ::= OBJECT IDENTIFIER
-
-rectangleModule1-oid ExampleOID
- ::= { 1 3 6 1 4 1 9363 1 5 2 1 1 }
-
--- An identifier of the Internet.
-internet-id OBJECT IDENTIFIER
- ::= { iso(1) identified-organization(3)
- dod(6) internet(1) }
-</PRE>
-</BLOCKQUOTE>
-As you see, names are optional.
-
-<P>
-
-<H2><A NAME="SECTION02116000000000000000">
-The RELATIVE-OID type</A>
-</H2>
-
-<P>
-The RELATIVE-OID type has the semantics of a subtree of an OBJECT
-IDENTIFIER. There may be no need to repeat the whole sequence of numbers
-from the root of the registration tree where the only thing of interest
-is some of the tree's subsequence.
-
-<P>
-
-<BLOCKQUOTE><PRE>
-this-document RELATIVE-OID ::= { docs(2) usage(1) }
-
-this-example RELATIVE-OID ::= {
- this-document assorted-examples(0) this-example(1) }
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H1><A NAME="SECTION02120000000000000000">
-Some of the ASN.1 String Types</A>
-</H1>
-
-<P>
-
-<H2><A NAME="SECTION02121000000000000000">
-The IA5String type</A>
-</H2>
-
-<P>
-This is essentially the ASCII, with 128 character codes available
-(7 lower bits of an 8-bit byte).
-
-<P>
-
-<H2><A NAME="SECTION02122000000000000000">
-The UTF8String type</A>
-</H2>
-
-<P>
-This is the character string which encodes the full Unicode range
-(4 bytes) using multibyte character sequences.
-
-<P>
-
-<H2><A NAME="SECTION02123000000000000000">
-The NumericString type</A>
-</H2>
-
-<P>
-This type represents the character string with the alphabet consisting
-of numbers (''0'' to ''9'') and a space.
-
-<P>
-
-<H2><A NAME="SECTION02124000000000000000">
-The PrintableString type</A>
-</H2>
-
-<P>
-The character string with the following alphabet: space, ''<B>'</B>''
-(single quote), ''<B>(</B>'', ''<B>)</B>'', ''<B>+</B>'',
-''<B>,</B>'' (comma), ''<B>-</B>'', ''<B>.</B>'', ''<B>/</B>'',
-digits (''0'' to ''9''), ''<B>:</B>'', ''<B>=</B>'', ''<B>?</B>'',
-upper-case and lower-case letters (''A'' to ''Z'' and ''a''
-to ''z'').
-
-<P>
-
-<H2><A NAME="SECTION02125000000000000000">
-The VisibleString type</A>
-</H2>
-
-<P>
-The character string with the alphabet which is more or less a subset
-of ASCII between the space and the ''<B>~</B>''
-symbol (tilde).
-
-<P>
-Alternatively, the alphabet may be described as the PrintableString
-alphabet presented earlier, plus the following characters: ''<B>!</B>'',
-''<B>''</B>'', ''<B>#</B>'', ''<B>$</B>'', ''<B>%</B>'',
-''<B>&</B>'', ''<B>*</B>'', ''<B>;</B>'', ''<B><</B>'',
-''<B>></B>'', ''<B>[</B>'', ''<B>\</B>'',
-''<B>]</B>'', ''<B>^</B>'', ''<B>_</B>'',
-''<B>`</B>'' (single left quote), ''<B>{</B>'', ''<B>|</B>'',
-''<B>}</B>'', ''<B>~</B>''.
-
-<P>
-
-<H1><A NAME="SECTION02130000000000000000">
-ASN.1 Constructed Types</A>
-</H1>
-
-<P>
-
-<H2><A NAME="SECTION02131000000000000000">
-The SEQUENCE type</A>
-</H2>
-
-<P>
-This is an ordered collection of other simple or constructed types.
-The SEQUENCE constructed type resembles the C ''struct'' statement.
-
-<P>
-
-<BLOCKQUOTE><PRE>
-Address ::= SEQUENCE {
- -- The apartment number may be omitted
- apartmentNumber NumericString OPTIONAL,
- streetName PrintableString,
- cityName PrintableString,
- stateName PrintableString,
- -- This one may be omitted too
- zipNo NumericString OPTIONAL
-}
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H2><A NAME="SECTION02132000000000000000">
-The SET type</A>
-</H2>
-
-<P>
-This is a collection of other simple or constructed types. Ordering
-is not important. The data may arrive in the order which is different
-from the order of specification. Data is encoded in the order not
-necessarily corresponding to the order of specification.
-
-<P>
-
-<H2><A NAME="SECTION02133000000000000000">
-The CHOICE type</A>
-</H2>
-
-<P>
-This type is just a choice between the subtypes specified in it. The
-CHOICE type contains at most one of the subtypes specified, and it
-is always implicitly known which choice is being decoded or encoded.
-This one resembles the C ''union'' statement.
-
-<P>
-The following type defines a response code, which may be either an
-integer code or a boolean ''true''/''false'' code.
-
-<P>
-
-<BLOCKQUOTE><PRE>
-ResponseCode ::= CHOICE {
- intCode INTEGER,
- boolCode BOOLEAN
-}
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H2><A NAME="SECTION02134000000000000000">
-The SEQUENCE OF type</A>
-</H2>
-
-<P>
-This one is the list (array) of simple or constructed types:
-
-<P>
-
-<BLOCKQUOTE><PRE>
--- Example 1
-ManyIntegers ::= SEQUENCE OF INTEGER
-
--- Example 2
-ManyRectangles ::= SEQUENCE OF Rectangle
-
--- More complex example:
--- an array of structures defined in place.
-ManyCircles ::= SEQUENCE OF SEQUENCE {
- radius INTEGER
- }
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H2><A NAME="SECTION02135000000000000000">
-The SET OF type</A>
-</H2>
-
-<P>
-The SET OF type models the bag of structures. It resembles the SEQUENCE
-OF type, but the order is not important: i.e. the elements may arrive
-in the order which is not necessarily the same as the in-memory order
-on the remote machines.
-
-<P>
-
-<BLOCKQUOTE><PRE>
--- A set of structures defined elsewhere
-SetOfApples :: SET OF Apple
-
--- Set of integers encoding the kind of a fruit
-FruitBag ::= SET OF ENUMERATED { apple, orange }
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H1><A NAME="SECTION03000000000000000000">
-Using the ASN.1 Compiler</A>
-</H1>
-
-<P>
-
-<H1><A NAME="SECTION03100000000000000000">
-Introduction to the ASN.1 Compiler</A>
-</H1>
-
-<P>
-The purpose of the ASN.1 compiler, of which this document is part,
-is to convert the ASN.1 specifications to some other target language
-(currently, only C is supported<A NAME="tex2html1"
- HREF="#foot159"><SUP>2.1</SUP></A>). The compiler reads the specification and emits a series of target
-language structures and surrounding maintenance code. For example,
-the C structure which may be created by compiler to represent the
-simple <I>Rectangle</I> specification defined earlier in this document,
-may look like this<A NAME="tex2html2"
- HREF="#foot803"><SUP>2.2</SUP></A>:
+The compiler would read this ASN.1 definition and produce the following
+C type<A NAME="tex2html2"
+ HREF="#foot819"><SUP>1.2</SUP></A>:
<P>
@@ -597,37 +206,35 @@
} Rectangle_t;
</PRE>
</BLOCKQUOTE>
-This would not be of much value for such a simple specification, so
-the compiler goes further and actually produces the code which fills
-in this structure by parsing the opaque binary<A NAME="tex2html3"
- HREF="#foot166"><SUP>2.3</SUP></A> data provided in some buffer. It also produces the code that takes
-this structure as an argument and performs structure serialization
-by emitting a series of bytes.
+It would also create the code for converting this structure into platform-independent
+wire representation (a serializer API) and the decoder of such wire
+representation back into local, machine-specific type (a deserializer
+API).
<P>
-<H1><A NAME="SECTION03200000000000000000">
-Quick start</A>
+<H1><A NAME="SECTION02110000000000000000">
+Quick start with asn1c</A>
</H1>
<P>
-After building and installing the compiler, the <I>asn1c</I><A NAME="tex2html4"
- HREF="#foot804"><SUP>3.1</SUP></A> command may be used to compile the ASN.1 specification<A NAME="tex2html5"
- HREF="#foot805"><SUP>3.2</SUP></A>:
+After building and installing the compiler, the <I>asn1c</I><A NAME="tex2html3"
+ HREF="#foot820"><SUP>1.3</SUP></A> command may be used to compile the ASN.1 module<A NAME="tex2html4"
+ HREF="#foot821"><SUP>1.4</SUP></A>:
<P>
<BLOCKQUOTE><PRE>
-asn1c <I><spec.asn1></I>
+asn1c <I><module.asn1></I>
</PRE>
</BLOCKQUOTE>
-If several specifications contain interdependencies, all of the files
+If several ASN.1 modules contain interdependencies, all of the files
must be specified altogether:
<P>
<BLOCKQUOTE><PRE>
-asn1c <I><spec1.asn1> <spec2.asn1> ...</I>
+asn1c <I><module1.asn1> <module2.asn1> ...</I>
</PRE>
</BLOCKQUOTE>
The compiler <B>-E</B> and <B>-EF</B> options are used for testing
@@ -640,7 +247,7 @@
<P>
<BLOCKQUOTE><PRE>
-asn1c <B>-EF</B> <I><spec-to-test.asn1></I>
+asn1c <B>-EF</B> <I><module-to-test.asn1></I>
</PRE>
</BLOCKQUOTE>
The <B>-P</B> option is used to dump the compiled output on the
@@ -657,20 +264,62 @@
<P>
<BLOCKQUOTE><PRE>
-asn1c <B>-P</B> <I><spec-to-compile-and-print.asn1></I>
+asn1c <B>-P</B> <I><module-to-compile-and-print.asn1></I>
</PRE>
</BLOCKQUOTE>
<P>
-<H1><A NAME="SECTION03300000000000000000">
-Using the ASN.1 Compiler</A>
+<H1><A NAME="SECTION02120000000000000000">
+Recognizing compiler output</A>
</H1>
<P>
+After compiling, the following entities will be created in your current
+directory:
-<H1><A NAME="SECTION03310000000000000000">
-Command-line options</A>
+<P>
+
+<UL>
+<LI>A set of .c and .h files, generally a single pair for each type defined
+in the ASN.1 specifications. These files will be named similarly to
+the ASN.1 types (<I>Rectangle.c</I> and <I>Rectangle.h</I> for the
+RectangleTest ASN.1 module defined in the beginning of this document).
+</LI>
+<LI>A set of helper .c and .h files which contain generic encoders, decoders
+and other useful routines. There will be quite a few of them, some
+of them even are not always necessary, but the overall amount of code
+after compilation will be rather small anyway.
+</LI>
+<LI>A <I>Makefile.am.sample</I> file mentioning all the files created
+at the earlier steps. This file is suitable for either automake suite
+or the plain `make` utility.
+</LI>
+</UL>
+It is your responsibility to create .c file with the <I>int main()</I>
+routine.
+
+<P>
+In other words, after compiling the Rectangle module, you have the
+following set of files: { Makefile.am.sample, Rectangle.c, Rectangle.h,
+<B>...</B> }, where <B>''...''</B> stands for the
+set of additional ''helper'' files created by the compiler. If you
+add a simple file with the <I>int main()</I> routine, it would even
+be possible to compile everything with the single instruction:
+
+<P>
+
+<BLOCKQUOTE><PRE>
+cc -I. -o rectangle.exe *.c # It could be <I>that</I> simple
+</PRE>
+</BLOCKQUOTE>
+Refer to the Chapter cha:Step-by-step-examples for a sample
+<I>int main()</I> routine.
+
+<P>
+
+<H1><A NAME="SECTION02130000000000000000">
+Command line options</A>
</H1>
<P>
@@ -679,7 +328,7 @@
<P>
<BR><P></P>
-<DIV ALIGN="CENTER"><A NAME="808"></A>
+<DIV ALIGN="CENTER"><A NAME="826"></A>
<TABLE>
<CAPTION><STRONG><A NAME=Table1>Table 1:</A></STRONG>
The list of asn1c command line options</CAPTION>
@@ -784,59 +433,21 @@
<P>
-<H1><A NAME="SECTION03320000000000000000">
-Recognizing compiler output</A>
+<H1><A NAME="SECTION02200000000000000000">
+Using the ASN.1 Compiler</A>
</H1>
<P>
-After compiling, the following entities will be created in your current
-directory:
-<P>
-
-<UL>
-<LI>A set of .c and .h files, generally a single pair for each type defined
-in the ASN.1 specifications. These files will be named similarly to
-the ASN.1 types (<I>Rectangle.c</I> and <I>Rectangle.h</I> for the
-specification defined in the beginning of this document).
-</LI>
-<LI>A set of helper .c and .h files which contain generic encoders, decoders
-and other useful routines. There will be quite a few of them, some
-of them even are not always necessary, but the overall amount of code
-after compiling will be rather small anyway.
-</LI>
-</UL>
-It is your responsibility to create .c file with the <I>int main()</I>
-routine and the Makefile (if needed). Compiler helps you with the
-latter by creating the Makefile.am.sample, containing the skeleton
-definition for the automake, should you want to use autotools.
-
-<P>
-In other words, after compiling the Rectangle module, you have the
-following set of files: { Makefile.am.sample, Rectangle.c, Rectangle.h,
-<B>...</B> }, where <B>''...''</B> stands for the
-set of additional ''helper'' files created by the compiler. If you
-add the simple file with the <I>int main()</I> routine, it would even
-be possible to compile everything with the single instruction:
-
-<P>
-
-<BLOCKQUOTE><PRE>
-cc -o rectangle *.c # It could be <I>that</I> simple<A NAME="tex2html7"
- HREF="#foot811"><SUP>4.1</SUP></A>
-</PRE>
-</BLOCKQUOTE>
-
-<P>
-
-<H1><A NAME="SECTION03330000000000000000">
-Invoking the ASN.1 helper code from an application</A>
+<H1><A NAME="SECTION02210000000000000000">
+Invoking the ASN.1 helper code</A>
</H1>
<P>
-First of all, you should to include one or more header files into
-your application. For our Rectangle module, including the Rectangle.h
-file is enough:
+First of all, you should include one or more header files into your
+application. Typically, it is enough to include the header file of
+the main PDU type. For our Rectangle module, including the Rectangle.h
+file is sufficient:
<P>
@@ -861,30 +472,38 @@
</BLOCKQUOTE>
This code defines a <I>rect</I> pointer which points to the Rectangle_t
structure which needs to be freed. The second line invokes the generic
-free_struct routine created specifically for this Rectangle_t structure.
-The <I>asn_DEF_Rectangle</I> is the type descriptor, which holds
-a collection of generic routines to deal with the Rectangle_t structure.
+<I>free_struct()</I> routine created specifically for this Rectangle_t
+structure. The <I>asn_DEF_Rectangle</I> is the type descriptor,
+which holds a collection of routines to deal with the Rectangle_t
+structure.
<P>
-There are several generic functions available:
+The following member functions of the asn_DEF_Rectangle type descriptor
+are of interest:
<P>
<DL>
<DT><STRONG>ber_decoder</STRONG></DT>
-<DD>This is the generic <I>restartable</I><A NAME="tex2html8"
- HREF="#foot253"><SUP>4.2</SUP></A> BER decoder (Basic Encoding Rules). This decoder would create
+<DD>This is the generic <I>restartable</I><A NAME="tex2html6"
+ HREF="#foot156"><SUP>2.1</SUP></A> BER decoder (Basic Encoding Rules). This decoder would create
and/or fill the target structure for you. Please refer to Section
-[<A HREF="#sub:Decoding-BER">Decoding BER</A>].
+sub:Decoding-BER.
</DD>
<DT><STRONG>der_encoder</STRONG></DT>
<DD>This is the generic DER encoder (Distinguished Encoding
Rules). This encoder will take the target structure and encode it
-into a series of bytes. Please refer to Section [<A HREF="#sub:Encoding-DER">Encoding DER</A>].
+into a series of bytes. Please refer to Section <A HREF="#sub:Encoding-DER">Encoding DER</A>.
</DD>
<DT><STRONG>xer_encoder</STRONG></DT>
-<DD>This is the generic XER encoder (XML Encoding Rules).
-This encoder will take the target structure and represent it as an
-XML (text) document. Please refer to Section [<A HREF="#sub:Encoding-XER">Encoding XER</A>].
+<DD>This is the XER encoder (XML Encoding Rules). This
+encoder will take the target structure and represent it as an XML
+(text) document using either BASIC-XER or CANONICAL-XER encoding rules.
+Please refer to Section <A HREF="#sub:Encoding-XER">Encoding XER</A>.
+</DD>
+<DT><STRONG>xer_decoder</STRONG></DT>
+<DD>This is the generic XER decoder. It takes both BASIC-XER
+or CANONICAL-XER encodings and deserializes the data into a local,
+machine-dependent representation. Please refer to Section <A HREF="#sub:Decoding-XER">Decoding XER</A>.
</DD>
<DT><STRONG>check_constraints</STRONG></DT>
<DD>Check that the contents of the target structure
@@ -895,25 +514,64 @@
<DD>This function convert the contents of the passed target
structure into human readable form. This form is not formal and cannot
be converted back into the structure, but it may turn out to be useful
-for debugging or quick-n-dirty printing. Please refer to Section [<A HREF="#sub:Printing-the-target">Printing the target</A>].
+for debugging or quick-n-dirty printing. Please refer to Section <A HREF="#sub:Printing-the-target">Printing the target</A>.
</DD>
<DT><STRONG>free_struct</STRONG></DT>
<DD>This is a generic disposal which frees the target structure.
-Please refer to Section [<A HREF="#sub:Freeing-the-target">Freeing the target</A>].
+Please refer to Section <A HREF="#sub:Freeing-the-target">Freeing the target</A>.
</DD>
</DL>
-check_constraints Check that the contents of the target structure
-are semantically valid and constrained to appropriate implicit or
-explicit subtype constraints. Please refer to Section <A HREF="#sub:Validating-the-target">Validating the target</A>.
-
-<P>
Each of the above function takes the type descriptor (<I>asn_DEF_...</I>)
-and the target structure (<I>rect</I>, in the above example). The
-target structure is typically created by the generic BER decoder or
-by the application itself.
+and the target structure (<I>rect</I>, in the above example).
<P>
-Here is how the buffer can be deserialized into the structure:
+
+<H2><A NAME="SECTION02211000000000000000"></A><A NAME="sub:Decoding-BER"></A><BR>
+Decoding BER
+</H2>
+
+<P>
+The Basic Encoding Rules describe the most widely used (by the ASN.1
+community) way to encode and decode a given structure in a machine-independent
+way. Several other encoding rules (CER, DER) define a more restrictive
+versions of BER, so the generic BER parser is also capable of decoding
+the data encoded by CER and DER encoders. The opposite is not true.
+
+<P>
+<I>The ASN.1 compiler provides the generic BER decoder which is
+implicitly capable of decoding BER, CER and DER encoded data.</I>
+
+<P>
+The decoder is restartable (stream-oriented), which means that in
+case the buffer has less data than it is expected, the decoder will
+process whatever there is available and ask for more data to be provided.
+Please note that the decoder may actually process less data than it
+was given in the buffer, which means that you must be able to make
+the next buffer contain the unprocessed part of the previous buffer.
+
+<P>
+Suppose, you have two buffers of encoded data: 100 bytes and 200 bytes.
+
+<P>
+
+<UL>
+<LI>You may concatenate these buffers and feed the BER decoder with 300
+bytes of data, or
+</LI>
+<LI>You may feed it the first buffer of 100 bytes of data, realize that
+the ber_decoder consumed only 95 bytes from it and later feed the
+decoder with 205 bytes buffer which consists of 5 unprocessed bytes
+from the first buffer and the additional 200 bytes from the second
+buffer.
+</LI>
+</UL>
+This is not as convenient as it could be (like, the BER encoder could
+consume the whole 100 bytes and keep these 5 bytes in some temporary
+storage), but in case of existing stream based processing it might
+actually fit well into existing algorithm. Suggestions are welcome.
+
+<P>
+Here is the simplest example of BER decoding.
<P>
@@ -923,7 +581,7 @@
Rectangle_t *rect = 0; /* Note this 0! */
asn_dec_rval_t rval;
- rval = asn_DEF_Rectangle->ber_decoder(0,
+ rval = <B>asn_DEF_Rectangle->ber_decoder</B>(0,
&asn_DEF_Rectangle,
(void **)&rect,
buffer, buf_size,
@@ -941,76 +599,22 @@
</PRE>
</BLOCKQUOTE>
The code above defines a function, <I>simple_deserializer</I>, which
-takes a buffer and its length and expected to return a pointer to
-the Rectangle_t structure. Inside, it tries to convert the bytes
-passed into the target structure (rect) using the generic BER decoder
-and returns the rect pointer afterwards. If the structure cannot be
-deserialized, it frees the memory which might be left allocated by
-the unfinished <I>ber_decoder</I> routine and returns NULL. <B>This
-freeing is necessary</B> because the ber_decoder is a restartable procedure,
+takes a buffer and its length and is expected to return a pointer
+to the Rectangle_t structure. Inside, it tries to convert the bytes
+passed into the target structure (rect) using the BER decoder and
+returns the rect pointer afterwards. If the structure cannot be deserialized,
+it frees the memory which might be left allocated by the unfinished
+<I>ber_decoder</I> routine and returns 0 (no data). (This <B>freeing
+is necessary</B> because the ber_decoder is a restartable procedure,
and may fail just because there is more data needs to be provided
-before decoding could be finalized. The code above obviously does
-not take into account the way the <I>ber_decoder</I> failed, so the
-freeing is necessary because the part of the buffer may already be
-decoded into the structure by the time something goes wrong.
+before decoding could be finalized). The code above obviously does
+not take into account the way the <I>ber_decoder()</I> failed, so
+the freeing is necessary because the part of the buffer may already
+be decoded into the structure by the time something goes wrong.
<P>
-Restartable decoding is a little bit trickier: you need to provide
-the old target structure pointer (which might be already half-decoded)
-and react on RC_WMORE return code. This will be explained later in
-Section <A HREF="#sub:Decoding-BER">Decoding BER</A>
-
-<P>
-
-<H2><A NAME="SECTION03331000000000000000"></A><A NAME="sub:Decoding-BER"></A><BR>
-Decoding BER
-</H2>
-
-<P>
-The Basic Encoding Rules describe the basic way how the structure
-can be encoded and decoded. Several other encoding rules (CER, DER)
-define a more restrictive versions of BER, so the generic BER parser
-is also capable of decoding the data encoded by CER and DER encoders.
-The opposite is not true.
-
-<P>
-The ASN.1 compiler provides the generic BER decoder which is implicitly
-capable of decoding BER, CER and DER encoded data.
-
-<P>
-The decoder is restartable (stream-oriented), which means that in
-case the buffer has less data than it is expected, the decoder will
-process whatever it is available and ask for more data to be provided.
-Please note that the decoder may actually process less data than it
-is given in the buffer, which means that you should be able to make
-the next buffer contain the unprocessed part of the previous buffer.
-
-<P>
-Suppose, you have two buffers of encoded data: 100 bytes and 200 bytes.
-
-<P>
-
-<UL>
-<LI>You may concatenate these buffers and feed the BER decoder with 300
-bytes of data, or
-</LI>
-<LI>You may feed it the first buffer of 100 bytes of data, realize that
-the ber_decoder consumed only 95 bytes from it and later feed the
-decoder with 205 bytes buffer which consists of 5 unprocessed bytes
-from the first buffer and the latter 200 bytes from the second buffer.
-</LI>
-</UL>
-This is not as convenient as it could be (like, the BER encoder would
-consume the whole 100 bytes and keep these 5 bytes in some temporary
-storage), but in case of stream-based processing it might actually
-be OK. Suggestions are welcome.
-
-<P>
-There are two ways to invoke a BER decoder. The first one is a direct
-reference of the type-specific decoder. This way was shown in the
-previous example of <I>simple_deserializer</I> function. The second
-way is to invoke a <I>ber_decode</I> function, which is just a simple
-wrapper of the former approach into a less wordy notation:
+A little less wordy would be to invoke a globally available <I>ber_decode()</I>
+function instead of dereferencing the asn_DEF_Rectangle type descriptor:
<P>
@@ -1023,7 +627,7 @@
is gone, and also the last argument (0) is no longer necessary.
<P>
-These two ways of invocations are fully equivalent.
+These two ways of BER decoder invocations are fully equivalent.
<P>
The BER de<I>coder</I> may fail because of (<I>the following RC_...
@@ -1054,7 +658,7 @@
<P>
-<H2><A NAME="SECTION03332000000000000000"></A><A NAME="sub:Encoding-DER"></A><BR>
+<H2><A NAME="SECTION02212000000000000000"></A><A NAME="sub:Encoding-DER"></A><BR>
Encoding DER
</H2>
@@ -1064,8 +668,8 @@
where all the lengths are known beforehand. This is probably exactly
how you want to encode: either after a BER decoding or after a manual
fill-up, the target structure contains the data which size is implicitly
-known before encoding. The DER encoding is used, for example, to encode
-X.509 certificates.
+known before encoding. Among other uses, the DER encoding is used
+to encode X.509 certificates.
<P>
As with BER decoder, the DER encoder may be invoked either directly
@@ -1114,8 +718,8 @@
DER encoder will essentially do the same thing (i.e., encode the data)
but no callbacks will be invoked (so the data goes nowhere). It may
prove useful to determine the size of the structure's encoding before
-actually doing the encoding<A NAME="tex2html9"
- HREF="#foot322"><SUP>4.3</SUP></A>.
+actually doing the encoding<A NAME="tex2html7"
+ HREF="#foot225"><SUP>2.2</SUP></A>.
<P>
Please look into der_encoder.h for the precise definition of der_encode()
@@ -1123,7 +727,7 @@
<P>
-<H2><A NAME="SECTION03333000000000000000"></A><A NAME="sub:Encoding-XER"></A><BR>
+<H2><A NAME="SECTION02213000000000000000"></A><A NAME="sub:Encoding-XER"></A><BR>
Encoding XER
</H2>
@@ -1150,7 +754,7 @@
print_as_XML(FILE *ostream, Rectangle_t *rect) {
asn_enc_rval_t er; /* Encoder return value */
- er = xer_encode(&asn_DEF_Rect, rect,
+ er = xer_encode(&asn_DEF_Rectangle, rect,
XER_F_BASIC, /* BASIC-XER or CANONICAL-XER */
write_stream, ostream);
@@ -1167,7 +771,48 @@
<P>
-<H2><A NAME="SECTION03334000000000000000"></A><A NAME="sub:Validating-the-target"></A><BR>
+<H2><A NAME="SECTION02214000000000000000"></A><A NAME="sub:Decoding-XER"></A><BR>
+Decoding XER
+</H2>
+
+<P>
+The data encoded using the XER rules can be subsequently decoded using
+the xer_decode() API call:
+
+<P>
+
+<BLOCKQUOTE><PRE>
+Rectangle_t *
+XML_to_Rectangle(const void *buffer, size_t buf_size) {
+ Rectangle_t *rect = 0; /* Note this 0! */
+ asn_dec_rval_t rval;
+
+ rval = xer_decode(0, &asn_DEF_Rectangle, (void **)&rect,
+ buffer, buf_size);
+ if(rval<B>.code</B> == RC_OK) {
+ return rect; /* Decoding succeeded */
+ } else {
+ /* Free partially decoded rect */
+ asn_DEF_Rectangle->free_struct(
+ &asn_DEF_Rectangle, rect, 0);
+ return 0;
+ }
+}
+</PRE>
+</BLOCKQUOTE>
+The decoder takes both BASIC-XER and CANONICAL-XER encodings.
+
+<P>
+The decoder shares its data consumption properties with BER decoder;
+please read the Section <A HREF="#sub:Decoding-BER">Decoding BER</A> to know more.
+
+<P>
+Please look into xer_decoder.h for the precise definition of xer_decode()
+and related types.
+
+<P>
+
+<H2><A NAME="SECTION02215000000000000000"></A><A NAME="sub:Validating-the-target"></A><BR>
Validating the target structure
</H2>
@@ -1195,7 +840,7 @@
<P>
-<H2><A NAME="SECTION03335000000000000000"></A><A NAME="sub:Printing-the-target"></A><BR>
+<H2><A NAME="SECTION02216000000000000000"></A><A NAME="sub:Printing-the-target"></A><BR>
Printing the target structure
</H2>
@@ -1230,7 +875,7 @@
<P>
-<H2><A NAME="SECTION03336000000000000000"></A><A NAME="sub:Freeing-the-target"></A><BR>
+<H2><A NAME="SECTION02217000000000000000"></A><A NAME="sub:Freeing-the-target"></A><BR>
Freeing the target structure
</H2>
@@ -1257,13 +902,13 @@
to the Rectangle_t, but an in-place inclusion of the Rectangle_t
structure. If the freeing is necessary, the usual procedure of freeing
everything must not be applied to the &rect pointer itself, because
-it does not point to the memory block directly allocated by memory
-allocation routine, but instead lies within such a block allocated
-for my_figure structure.
+it does not point to the memory block directly allocated by the memory
+allocation routine, but instead lies within a block allocated for
+the my_figure structure.
<P>
To solve this problem, the free_struct routine has the additional
-argument (besides the intuitive type descriptor and target structure
+argument (besides the obvious type descriptor and target structure
pointers), which is the flag specifying whether the outer pointer
itself must be freed (0, default) or it should be left intact (non-zero
value).
@@ -1271,23 +916,26 @@
<P>
<BLOCKQUOTE><PRE>
-/* Rectangle_t is defined within my_figure */
-struct my_figure *mf = <B>...</B>;
+<B>/* 1. Rectangle_t is defined within my_figure */</B>
+struct my_figure {
+ Rectangle_t rect;
+} *mf = <B>...</B>;
/*
- * Freeing the Rectangle_td
- * without freeing the mf->rect pointer
+ * Freeing the Rectangle_t
+ * without freeing the mf->rect area
*/
asn_DEF_Rectangle->free_struct(
- &asn_DEF_Rectangle, &mf->rect, <I>1</I> /* !free */);
-
-/* Rectangle_t is a stand-alone pointer */
+ &asn_DEF_Rectangle, &mf->rect, <B>1</B> <B>/* !free */</B>);
+
+
+<B>/* 2. Rectangle_t is a stand-alone pointer */</B>
Rectangle_t *rect = <B>...</B>;
/*
* Freeing the Rectangle_t
* and freeing the rect pointer
*/
asn_DEF_Rectangle->free_struct(
- &asn_DEF_Rectangle, rect, <I>0</I> /* free the pointer too */);
+ &asn_DEF_Rectangle, rect, <B>0</B> <B>/* free the pointer too */</B>);
</PRE>
</BLOCKQUOTE>
It is safe to invoke the <I>free_struct</I> function with the target
@@ -1295,19 +943,13 @@
<P>
-<H1><A NAME="SECTION04000000000000000000">
-Examples</A>
-</H1>
-
-<P>
-
-<H1><A NAME="SECTION04100000000000000000"></A><A NAME="cha:Step-by-step-examples"></A><BR>
+<H1><A NAME="SECTION02300000000000000000"></A><A NAME="cha:Step-by-step-examples"></A><BR>
Step by step examples
</H1>
<P>
-<H1><A NAME="SECTION04110000000000000000">
+<H1><A NAME="SECTION02310000000000000000">
A ''Rectangle'' Encoder</A>
</H1>
@@ -1449,7 +1091,7 @@
<P>
-<H1><A NAME="SECTION04120000000000000000"></A><A NAME="sec:A-Rectangle-Decoder"></A><BR>
+<H1><A NAME="SECTION02320000000000000000"></A><A NAME="sec:A-Rectangle-Decoder"></A><BR>
A ''Rectangle'' Decoder
</H1>
@@ -1575,7 +1217,7 @@
<P>
-<H1><A NAME="SECTION04200000000000000000">
+<H1><A NAME="SECTION02400000000000000000">
Constraint validation examples</A>
</H1>
@@ -1585,7 +1227,7 @@
<P>
-<H1><A NAME="SECTION04210000000000000000">
+<H1><A NAME="SECTION02410000000000000000">
Adding constraints into ''Rectangle'' type</A>
</H1>
@@ -1619,8 +1261,8 @@
<LI>Modify the Rectangle type processing routine (you can start with the
main() routine shown in the Section <A HREF="#sec:A-Rectangle-Decoder">A Rectangle Decoder</A>)
by placing the following snippet of code <I>before</I> encoding and/or
-<I>after</I> decoding the Rectangle type<A NAME="tex2html10"
- HREF="#foot876"><SUP>6.1</SUP></A>:
+<I>after</I> decoding the Rectangle type<A NAME="tex2html8"
+ HREF="#foot898"><SUP>4.1</SUP></A>:
<P>
@@ -1656,8 +1298,424 @@
</LI>
<LI>Done.
</LI>
-</OL>
-<H2><A NAME="SECTION05000000000000000000">
+</OL>
+
+<P>
+
+<H1><A NAME="SECTION03000000000000000000"></A><A NAME="par:ASN.1-Basics"></A><BR>
+ASN.1 Basics
+</H1>
+
+<P>
+
+<H1><A NAME="SECTION03100000000000000000"></A><A NAME="cha:Abstract-Syntax-Notation:"></A><BR>
+Abstract Syntax Notation: ASN.1
+</H1>
+
+<P>
+<I>This chapter defines some basic ASN.1 concepts and describes
+several most widely used types. It is by no means an authoritative
+or complete reference. For more complete ASN.1 description, please
+refer to Olivier Dubuisson's book [<A
+ HREF="asn1c-usage.html#Dub00">Dub00</A>] or the ASN.1 body
+of standards itself [<A
+ HREF="asn1c-usage.html#ITU-T_ASN.1">ITU-T/ASN.1</A>].</I>
+
+<P>
+The Abstract Syntax Notation One is used to formally describe the
+semantics of data transmitted across the network. Two communicating
+parties may have different formats of their native data types (i.e.
+number of bits in the integer type), thus it is important to have
+a way to describe the data in a manner which is independent from the
+particular machine's representation. The ASN.1 specifications are
+used to achieve the following:
+
+<P>
+
+<UL>
+<LI>The specification expressed in the ASN.1 notation is a formal and
+precise way to communicate the data semantics to human readers;
+</LI>
+<LI>The ASN.1 specifications may be used as input for automatic compilers
+which produce the code for some target language (C, C++, Java, etc)
+to encode and decode the data according to some encoding rules (which
+are also defined by the ASN.1 standard).
+</LI>
+</UL>
+Consider the following example:
+
+<P>
+
+<BLOCKQUOTE><PRE>
+Rectangle ::= SEQUENCE {
+ height INTEGER,
+ width INTEGER
+}
+</PRE>
+</BLOCKQUOTE>
+This ASN.1 specification describes a constructed type, <I>Rectangle</I>,
+containing two integer fields. This specification may tell the reader
+that there exists this kind of data structure and that some entity
+may be prepared to send or receive it. The question on <I>how</I>
+that entity is going to send or receive the <I>encoded data</I> is
+outside the scope of ASN.1. For example, this data structure may be
+encoded according to some encoding rules and sent to the destination
+using the TCP protocol. The ASN.1 specifies several ways of encoding
+(or ''serializing'', or ''marshaling'') the data: BER, PER, XER
+and others, including CER and DER derivatives from BER.
+
+<P>
+The complete specification must be wrapped in a module, which looks
+like this:
+
+<P>
+
+<BLOCKQUOTE><PRE>
+RectangleModule1
+ { iso org(3) dod(6) internet(1) private(4)
+ enterprise(1) spelio(9363) software(1)
+ asn1c(5) docs(2) rectangle(1) 1 }
+ DEFINITIONS AUTOMATIC TAGS ::=
+BEGIN
+
+-- This is a comment which describes nothing.
+Rectangle ::= SEQUENCE {
+ height INTEGER, -- Height of the rectangle
+ width INTEGER -- Width of the rectangle
+}
+
+END
+</PRE>
+</BLOCKQUOTE>
+The module header consists of module name (RectangleModule1), the
+module object identifier ({...}), a keyword ''DEFINITIONS'', a
+set of module flags (AUTOMATIC TAGS) and ''::= BEGIN''. The module
+ends with an ''END'' statement.
+
+<P>
+
+<H1><A NAME="SECTION03110000000000000000">
+Some of the ASN.1 Basic Types</A>
+</H1>
+
+<P>
+
+<H2><A NAME="SECTION03111000000000000000">
+The BOOLEAN type</A>
+</H2>
+
+<P>
+The BOOLEAN type models the simple binary TRUE/FALSE, YES/NO, ON/OFF
+or a similar kind of two-way choice.
+
+<P>
+
+<H2><A NAME="SECTION03112000000000000000">
+The INTEGER type</A>
+</H2>
+
+<P>
+The INTEGER type is a signed natural number type without any restrictions
+on its size. If the automatic checking on INTEGER value bounds are
+necessary, the subtype constraints must be used.
+
+<P>
+
+<BLOCKQUOTE><PRE>
+SimpleInteger ::= INTEGER
+
+-- An integer with a very limited range
+SmallPositiveInt ::= INTEGER (0..127)
+
+-- Integer, negative
+NegativeInt ::= INTEGER (MIN..0)
+</PRE>
+</BLOCKQUOTE>
+
+<P>
+
+<H2><A NAME="SECTION03113000000000000000">
+The ENUMERATED type</A>
+</H2>
+
+<P>
+The ENUMERATED type is semantically equivalent to the INTEGER type
+with some integer values explicitly named.
+
+<P>
+
+<BLOCKQUOTE><PRE>
+FruitId ::= ENUMERATED { apple(1), orange(2) }
+
+-- The numbers in braces are optional,
+-- the enumeration can be performed
+-- automatically by the compiler
+ComputerOSType ::= ENUMERATED {
+ FreeBSD, -- acquires value 0
+ Windows, -- acquires value 1
+ Solaris(5), -- remains 5
+ Linux, -- becomes 6
+ MacOS -- becomes 7
+}
+</PRE>
+</BLOCKQUOTE>
+
+<P>
+
+<H2><A NAME="SECTION03114000000000000000">
+The OCTET STRING type</A>
+</H2>
+
+<P>
+This type models the sequence of 8-bit bytes. This may be used to
+transmit some opaque data or data serialized by other types of encoders
+(i.e. video file, photo picture, etc).
+
+<P>
+
+<H2><A NAME="SECTION03115000000000000000">
+The OBJECT IDENTIFIER type</A>
+</H2>
+
+<P>
+The OBJECT IDENTIFIER is used to represent the unique identifier of
+any object, starting from the very root of the registration tree.
+If your organization needs to uniquely identify something (a router,
+a room, a person, a standard, or whatever), you are encouraged to
+get your own identification subtree at <A HREF=http://www.iana.org/protocols/forms.htm>http://www.iana.org/protocols/forms.htm</A>.
+
+<P>
+For example, the very first ASN.1 module in this Chapter (RectangleModule1)
+has the following OBJECT IDENTIFIER: 1 3 6 1 4 1 9363 1 5 2 1 1.
+
+<P>
+
+<BLOCKQUOTE><PRE>
+ExampleOID ::= OBJECT IDENTIFIER
+
+rectangleModule1-oid ExampleOID
+ ::= { 1 3 6 1 4 1 9363 1 5 2 1 1 }
+
+-- An identifier of the Internet.
+internet-id OBJECT IDENTIFIER
+ ::= { iso(1) identified-organization(3)
+ dod(6) internet(1) }
+</PRE>
+</BLOCKQUOTE>
+As you see, names are optional.
+
+<P>
+
+<H2><A NAME="SECTION03116000000000000000">
+The RELATIVE-OID type</A>
+</H2>
+
+<P>
+The RELATIVE-OID type has the semantics of a subtree of an OBJECT
+IDENTIFIER. There may be no need to repeat the whole sequence of numbers
+from the root of the registration tree where the only thing of interest
+is some of the tree's subsequence.
+
+<P>
+
+<BLOCKQUOTE><PRE>
+this-document RELATIVE-OID ::= { docs(2) usage(1) }
+
+this-example RELATIVE-OID ::= {
+ this-document assorted-examples(0) this-example(1) }
+</PRE>
+</BLOCKQUOTE>
+
+<P>
+
+<H1><A NAME="SECTION03120000000000000000">
+Some of the ASN.1 String Types</A>
+</H1>
+
+<P>
+
+<H2><A NAME="SECTION03121000000000000000">
+The IA5String type</A>
+</H2>
+
+<P>
+This is essentially the ASCII, with 128 character codes available
+(7 lower bits of an 8-bit byte).
+
+<P>
+
+<H2><A NAME="SECTION03122000000000000000">
+The UTF8String type</A>
+</H2>
+
+<P>
+This is the character string which encodes the full Unicode range
+(4 bytes) using multibyte character sequences.
+
+<P>
+
+<H2><A NAME="SECTION03123000000000000000">
+The NumericString type</A>
+</H2>
+
+<P>
+This type represents the character string with the alphabet consisting
+of numbers (''0'' to ''9'') and a space.
+
+<P>
+
+<H2><A NAME="SECTION03124000000000000000">
+The PrintableString type</A>
+</H2>
+
+<P>
+The character string with the following alphabet: space, ''<B>'</B>''
+(single quote), ''<B>(</B>'', ''<B>)</B>'', ''<B>+</B>'',
+''<B>,</B>'' (comma), ''<B>-</B>'', ''<B>.</B>'', ''<B>/</B>'',
+digits (''0'' to ''9''), ''<B>:</B>'', ''<B>=</B>'', ''<B>?</B>'',
+upper-case and lower-case letters (''A'' to ''Z'' and ''a''
+to ''z'').
+
+<P>
+
+<H2><A NAME="SECTION03125000000000000000">
+The VisibleString type</A>
+</H2>
+
+<P>
+The character string with the alphabet which is more or less a subset
+of ASCII between the space and the ''<B>~</B>''
+symbol (tilde).
+
+<P>
+Alternatively, the alphabet may be described as the PrintableString
+alphabet presented earlier, plus the following characters: ''<B>!</B>'',
+''<B>''</B>'', ''<B>#</B>'', ''<B>$</B>'', ''<B>%</B>'',
+''<B>&</B>'', ''<B>*</B>'', ''<B>;</B>'', ''<B><</B>'',
+''<B>></B>'', ''<B>[</B>'', ''<B>\</B>'',
+''<B>]</B>'', ''<B>^</B>'', ''<B>_</B>'',
+''<B>`</B>'' (single left quote), ''<B>{</B>'', ''<B>|</B>'',
+''<B>}</B>'', ''<B>~</B>''.
+
+<P>
+
+<H1><A NAME="SECTION03130000000000000000">
+ASN.1 Constructed Types</A>
+</H1>
+
+<P>
+
+<H2><A NAME="SECTION03131000000000000000">
+The SEQUENCE type</A>
+</H2>
+
+<P>
+This is an ordered collection of other simple or constructed types.
+The SEQUENCE constructed type resembles the C ''struct'' statement.
+
+<P>
+
+<BLOCKQUOTE><PRE>
+Address ::= SEQUENCE {
+ -- The apartment number may be omitted
+ apartmentNumber NumericString OPTIONAL,
+ streetName PrintableString,
+ cityName PrintableString,
+ stateName PrintableString,
+ -- This one may be omitted too
+ zipNo NumericString OPTIONAL
+}
+</PRE>
+</BLOCKQUOTE>
+
+<P>
+
+<H2><A NAME="SECTION03132000000000000000">
+The SET type</A>
+</H2>
+
+<P>
+This is a collection of other simple or constructed types. Ordering
+is not important. The data may arrive in the order which is different
+from the order of specification. Data is encoded in the order not
+necessarily corresponding to the order of specification.
+
+<P>
+
+<H2><A NAME="SECTION03133000000000000000">
+The CHOICE type</A>
+</H2>
+
+<P>
+This type is just a choice between the subtypes specified in it. The
+CHOICE type contains at most one of the subtypes specified, and it
+is always implicitly known which choice is being decoded or encoded.
+This one resembles the C ''union'' statement.
+
+<P>
+The following type defines a response code, which may be either an
+integer code or a boolean ''true''/''false'' code.
+
+<P>
+
+<BLOCKQUOTE><PRE>
+ResponseCode ::= CHOICE {
+ intCode INTEGER,
+ boolCode BOOLEAN
+}
+</PRE>
+</BLOCKQUOTE>
+
+<P>
+
+<H2><A NAME="SECTION03134000000000000000">
+The SEQUENCE OF type</A>
+</H2>
+
+<P>
+This one is the list (array) of simple or constructed types:
+
+<P>
+
+<BLOCKQUOTE><PRE>
+-- Example 1
+ManyIntegers ::= SEQUENCE OF INTEGER
+
+-- Example 2
+ManyRectangles ::= SEQUENCE OF Rectangle
+
+-- More complex example:
+-- an array of structures defined in place.
+ManyCircles ::= SEQUENCE OF SEQUENCE {
+ radius INTEGER
+ }
+</PRE>
+</BLOCKQUOTE>
+
+<P>
+
+<H2><A NAME="SECTION03135000000000000000">
+The SET OF type</A>
+</H2>
+
+<P>
+The SET OF type models the bag of structures. It resembles the SEQUENCE
+OF type, but the order is not important: i.e. the elements may arrive
+in the order which is not necessarily the same as the in-memory order
+on the remote machines.
+
+<P>
+
+<BLOCKQUOTE><PRE>
+-- A set of structures defined elsewhere
+SetOfApples :: SET OF Apple
+
+-- Set of integers encoding the kind of a fruit
+FruitBag ::= SET OF ENUMERATED { apple, orange }
+</PRE>
+</BLOCKQUOTE>
+
+<H2><A NAME="SECTION04000000000000000000">
Bibliography</A>
</H2><DL COMPACT><DD><P></P><DT><A NAME="ASN1C">ASN1C</A>
<DD>The Open Source ASN.1 Compiler. <A HREF=http://lionet.info/asn1c>http://lionet.info/asn1c</A>
@@ -1674,57 +1732,45 @@
<P>
<BR><HR><H4>Footnotes</H4>
<DL>
-<DT><A NAME="foot159">... supported</A><A
- HREF="asn1c-usage.html#tex2html1"><SUP>2.1</SUP></A></DT>
-<DD>C++ is ''supported'' too, as long as an class-based approach is
-not a definitive factor.
+<DT><A NAME="foot818">... given</A><A
+ HREF="asn1c-usage.html#tex2html1"><SUP>1.1</SUP></A></DT>
+<DD>Please look into Part par:ASN.1-Basics for a quick reference
+on how to understand the ASN.1 notation.
</DD>
-<DT><A NAME="foot803">... this</A><A
- HREF="asn1c-usage.html#tex2html2"><SUP>2.2</SUP></A></DT>
+<DT><A NAME="foot819">... type</A><A
+ HREF="asn1c-usage.html#tex2html2"><SUP>1.2</SUP></A></DT>
<DD><I>-fnative-types</I> compiler option is used to produce basic C <I>int</I>
types instead of infinite width INTEGER_t structures. See <A HREF=#Table1>Table 1</A>.
</DD>
-<DT><A NAME="foot166">... binary</A><A
- HREF="asn1c-usage.html#tex2html3"><SUP>2.3</SUP></A></DT>
-<DD>BER, CER and DER encodings are binary. However, the XER encoding is
-text (XML) based.
-
-</DD>
-<DT><A NAME="foot804">...asn1c</A><A
- HREF="asn1c-usage.html#tex2html4"><SUP>3.1</SUP></A></DT>
+<DT><A NAME="foot820">...asn1c</A><A
+ HREF="asn1c-usage.html#tex2html3"><SUP>1.3</SUP></A></DT>
<DD>The 1 symbol in asn<B>1</B>c is a digit, not an ''ell'' letter.
</DD>
-<DT><A NAME="foot805">... specification</A><A
- HREF="asn1c-usage.html#tex2html5"><SUP>3.2</SUP></A></DT>
+<DT><A NAME="foot821">... module</A><A
+ HREF="asn1c-usage.html#tex2html4"><SUP>1.4</SUP></A></DT>
<DD>This is probably <B>not</B> what you want to try out right now -
-read through the rest of this chapter to find out about <B>-P</B>
-and <B>-R</B> options.
+read through the rest of this chapter and check the <A HREF=#Table1>Table 1</A>
+to find out about <B>-P</B> and <B>-R</B> options.
</DD>
-<DT><A NAME="foot811">...that simple</A><A
- HREF="asn1c-usage.html#tex2html7"><SUP>4.1</SUP></A></DT>
-<DD>Provided that you've also created a .c file with the <I>int main()</I>
-routine.
-
-</DD>
-<DT><A NAME="foot253">...restartable</A><A
- HREF="asn1c-usage.html#tex2html8"><SUP>4.2</SUP></A></DT>
+<DT><A NAME="foot156">...restartable</A><A
+ HREF="asn1c-usage.html#tex2html6"><SUP>2.1</SUP></A></DT>
<DD>Restartable means that if the decoder encounters the end of the buffer,
it will fail, but may later be invoked again with the rest of the
buffer to continue decoding.
</DD>
-<DT><A NAME="foot322">... encoding</A><A
- HREF="asn1c-usage.html#tex2html9"><SUP>4.3</SUP></A></DT>
+<DT><A NAME="foot225">... encoding</A><A
+ HREF="asn1c-usage.html#tex2html7"><SUP>2.2</SUP></A></DT>
<DD>It is actually faster too: the encoder might skip over some computations
which aren't important for the size determination.
</DD>
-<DT><A NAME="foot876">... type</A><A
- HREF="asn1c-usage.html#tex2html10"><SUP>6.1</SUP></A></DT>
+<DT><A NAME="foot898">... type</A><A
+ HREF="asn1c-usage.html#tex2html8"><SUP>4.1</SUP></A></DT>
<DD>Placing the constraint checking code <I>before</I> encoding helps
to make sure you know the data is correct and within constraints before
sharing the data with anyone else.
@@ -1738,7 +1784,7 @@
</DL><BR><HR>
<ADDRESS>
Lev Walkin
-2005-02-02
+2005-02-21
</ADDRESS>
</BODY>
</HTML>