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What's New in the OSS ASN.1 Tools for C

Applies to: ASN.1/C 10.7

What's New in ASN.1/C 10.7

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.7.

New Features

Support for X.680 Amendment 1

The ASN.1 compiler now supports X.680 Amendment 1. The IMPORTS clause allows symbols to be imported from the latest module version, as indicated by the object identifier, and it can now include WITH SUCCESSORS and WITH DESCENDANTS as SelectionOption.

A special type of absolute reference notation

A special type of absolute reference notation that allows you to access ASN.1 types located within WITH COMPONENTS and WITH COMPONENT (inner subtype) clauses and consists of two dollar signs ($$) followed by an index number indicating a particular WITH COMPONENTS or WITH COMPONENT is now supported. You can now assign user-defined names within CONSTRAINED BY clauses that are present within an inner subtype or a compiler-generated structure.

An alternative form of encoding values

The JSON encoders now support an alternative form of encoding values of BIT STRING or OCTET STRING types with contents constraints if an ENCODED BY is absent. When you select this form, the values are encoded as text (the JSON value represents the contained value) rather than hex string.

New compiler directives

The OSS.JEREncodeFunction directive allows you to customize a JSON encoding of an ASN.1 type using a user-provided function that will generate the custom encoding. Note that the OSS.JEREncodeFunction directive is available only when the -soed or -toed compiler option is specified.

The OSS.NOENCODE and OSS.NODECODE compiler directives reduce the generated TOED code by excluding the encoding or decoding routines for the directive's operand. Under certain conditions, the generated code can be reduced even further using the new -compactNoDecode compiler option.

New compiler options

The -compactNoDecode compiler option instructs the compiler to generate a compact version of the Time-Optimized Decoder code for fields marked with the OSS.NODECODE directive.

The -jer command-line option is now an alias for the -json command-line option.

New samples
  • A sample for the DIN EN 15722 Intelligent transport systems - ESafety - ECall minimum set of data standard. The sample demonstrates how the ECallMessage message can be created and serialized to binary (UPER) and XML formats.
  • A sample for the eUICC Profile Package standard. The sample demonstrates how the eUICC Profile Package can be constructed and saved to the disk file in binary (DER) and text (JSON) formats.
  • A sample for the GSMA Remote SIM Provisioning standard. The sample demonstrates the RSP communication using the GetBoundProfilePackageRequest request to the SM-DP+ as an example.

New samples have been created for release 15 of the LTE and 5G protocols and the existing samples for releases 13 and 14 have been updated to the most recent versions of the ASN.1 schemas available. The samples for release 12 of the LTE protocols have been removed.

  • 5g_e1ap_r15 TS 38.463 V15.1.0 (2018-09)
  • 5g_e1ap_r15 TS 38.463 V15.3.0 (2018-09)
  • 5g_f1ap_r15 TS 38.473 V15.3.0 (2018-09)
  • 5g_ngap_r15 TS 38.413 V15.1.0 (2018-09)
  • 5g_xnap_r15 TS 38.423 V15.1.0 (2018-09)
  • lte_lcsap_r13 TS 29.171 V13.3.0 (2017-06)
  • lte_lcsap_r14 TS 29.171 V14.2.0 (2017-12)
  • lte_lcsap_r15 TS 29.171 V15.1.0 (2018-09)
  • lte_lppa_r13 TS 36.455 V13.1.0 (2016-03)
  • lte_lppa_r14 TS 36.455 V14.5.0 (2018-09)
  • lte_lppa_r15 TS 36.455 V15.1.0 (2018-09)
  • lte_m2ap_r13 TS 36.443 V13.3.0 (2016-03)
  • lte_m2ap_r14 TS 36.443 V14.1.0 (2018-09)
  • lte_m2ap_r15 TS 36.443 V15.0.0 (2018-09)
  • lte_m3ap_r13 TS 36.444 V13.2.0 (2016-03)
  • lte_m3ap_r14 TS 36.444 V14.1.0 (2017-06)
  • lte_m3ap_r15 TS 36.444 V15.0.0 (2018-09)
  • lte_rrc_cv2x_r14 TS 36.331 V14.8.0 (2018-09)
  • lte_rrc_nb_iot_r13 TS 36.331 V13.10.0 (2018-07)
  • lte_rrc_nb_iot_r14 TS 36.331 V14.8.0 (2018-09)
  • lte_rrc_r13 TS 36.331 V13.11.0 (2018-09)
  • lte_rrc_r14 TS 36.331 V14.8.0 (2018-09)
  • lte_rrc_r15 TS 36.331 V15.3.0 (2018-09)
  • lte_s1ap_nb_iot_r13 TS 36.413 V13.7.0 (2018-06)
  • lte_s1ap_nb_iot_r14 TS 36.413 V14.7.0 (2018-09)
  • lte_s1ap_r13 TS 36.413 V13.7.0 (2018-06)
  • lte_s1ap_r14 TS 36.413 V14.7.0 (2018-09)
  • lte_s1ap_r15 TS 36.413 V15.3.0 (2018-09)
  • lte_sbcap_r13 TS 29.168 V13.3.0 (2017-09)
  • lte_sbcap_r14 TS 29.168 V14.2.0 (2017-12)
  • lte_sbcap_r15 TS 29.168 V15.1.0 (2018-09)
  • lte_slmap_r15 TS 36.459 V15.0.0 (2018-01)
  • lte_x2ap_nb_iot_r13 TS 36.423 V13.7.0 (2017-06)
  • lte_x2ap_nb_iot_r14 TS 36.423 V14.6.0 (2018-06)
  • lte_x2ap_r13 TS 36.423 V13.7.0 (2017-06)
  • lte_x2ap_r14 TS 36.423 V14.6.0 (2018-06)
  • lte_x2ap_r15 TS 36.423 V15.3.0 (2018-09)
  • lte_xwap_r13 TS 36.463 V13.1.0 (2016-07)
  • lte_xwap_r14 TS 36.463 V14.2.0 (2017-06)
  • lte_xwap_r15 TS 36.463 V15.0.0 (2018-06)

Improvements

Improved handling of types within inner subtype constraints with nested CONSTRAINED BY or contents constraints:

  1. The ASN.1 compiler now generates user-defined functions for fields to which a CONSTRAINED BY included within a WITH COMPONENTS syntax is applied. The new compat flag, noConstrainedByFunctionsFromInnerSubtype, can be used to generate a user-defined function for the parent type.
  2. When contents constraints are applied within an inner subtype constraint, the generated representations of the base type and the constrained type are now different. The ASN.1 compiler no longer uses the same name for both representations when the TYPENAME directive is applied to the base type. The new compat flag, oldTypesFromInnerSubtypeWithContentConstraints, can be used to restore the previous behavior.
  3. The ASN.1 compiler no longer generates structures with additional pointers for circularly defined types with contents constraints applied within inner subtypes in helper mode. The new compat flag, v10.6PointeredTypesFromInnerWithContentConstraints, can be used to restore the previous behavior.
  4. The ASN.1/C compiler now preserves the same global define names and values that are generated for similar fields within artificial types created after applying a contents constraint within an inner subtype constraint. To generate mangled names, use the v10.6DefineNamesForTypesFromInnerWithContentConstraints compat flag.
  5. The ASN.1/C compiler now generates correct header files when the -splitHeader option is specified with the -c++ or -dualHeaders option and the input ASN.1 syntax includes an inner subtype and a contents constraint or a CONSTRAINED BY constraint. The oldLocationOfTypesFromInnerWithContentConstraints compat flag can be used to restore the previous behavior.

What's New in ASN.1/C 10.6

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.6.

New Features

Support for CPER

Support for the Canonical Packed Encoding Rules (ALIGNED and UNALIGNED) as specified by ITU-T Recommendation X.691 (08/2015) | ISO/IEC 8825-2:2015 has been added.

For better security, the CPER decoder operates in a strict mode: every deviation from the X.691 standard requirements is reported.

The JSON encoders encode a non-special REAL value as a JSON number. Previously, it could be encoded as a JSON object. For example, value 3.14 of an unconstrained REAL type was encoded as {base10value: 3.14}. The JSON decoders now accept both encoding forms: JSON number and JSON objects.

New compiler options

To enable support for CPER, use the new compiler options: -cper and -cuper.

New samples

A new sample that demonstrates processing of CDR files described by 3GPP TS 32.297 has been added. 3GPP CDR files contain a non-ASN.1 file header and non-ASN.1 record headers while record bodies are encoded by one of the ASN.1 encoding rules (BER, PER unaligned, PER aligned, or XER).

New samples have been created for 3GPP Release 14 of the LTE protocols and the existing Release 12 and 13 samples have been updated to the most recent versions of the ASN.1 schema:

  • lte_lcsap_r13 TS 29.171 V13.3.0 (2017-06)
  • lte_lcsap_r14 TS 29.171 V14.1.0 (2017-06)
  • lte_lppa_r13 TS 36.455 V13.1.0 (2016-03)
  • lte_lppa_r14 TS 36.455 V14.3.0 (2017-09)
  • lte_m2ap_r12 TS 36.443 V12.2.0 (2015-03)
  • lte_m2ap_r13 TS 36.443 V13.3.0 (2016-03)
  • lte_m2ap_r14 TS 36.443 V14.0.1 (2017-09)
  • lte_m3ap_r12 TS 36.444 V12.2.0 (2015-03)
  • lte_m3ap_r13 TS 36.444 V13.2.0 (2016-03)
  • lte_m3ap_r14 TS 36.444 V14.1.0 (2017-06)
  • lte_rrc_cv2x_r14 TS 36.331 V14.4.0 (2017-09)
  • lte_rrc_nb_iot_r13 TS 36.331 V13.7.1 (2017-09)
  • lte_rrc_nb_iot_r14 TS 36.331 V14.4.0 (2017-09)
  • lte_rrc_r12 TS 36.331 V12.15.1 (2017-09)
  • lte_rrc_r13 TS 36.331 V13.7.1 (2017-09)
  • lte_rrc_r14 TS 36.331 V14.4.0 (2017-09)
  • lte_s1ap_nb_iot_r13 TS 36.413 V13.6.0 (2017-06)
  • lte_s1ap_nb_iot_r14 TS 36.413 V14.4.0 (2017-10)
  • lte_s1ap_r12 TS 36.413 V12.7.0 (2016-03)
  • lte_s1ap_r13 TS 36.413 V13.6.0 (2017-06)
  • lte_s1ap_r14 TS 36.413 V14.4.0 (2017-10)
  • lte_sbcap_r12 TS 29.168 V12.10.0 (2017-09)
  • lte_sbcap_r13 TS 29.168 V13.3.0 (2017-09)
  • lte_sbcap_r14 TS 29.168 V14.1.0 (2017-09)
  • lte_x2ap_nb_iot_r13 TS 36.423 V13.7.0 (2017-06)
  • lte_x2ap_nb_iot_r14 TS 36.423 V14.4.0 (2017-09)
  • lte_x2ap_r12 TS 36.423 V12.9.0 (2016-07)
  • lte_x2ap_r13 TS 36.423 V13.7.0 (2017-06)
  • lte_x2ap_r14 TS 36.423 V14.4.0 (2017-09)
  • lte_xwap_r13 TS 36.463 V13.1.0 (2016-07)
  • lte_xwap_r14 TS 36.463 V14.2.0 (2017-06)

Improvements

The ASN.1 compiler supports the UPPERCAMELCASED and LOWERCAMELCASED keywords in the NAME and TEXT JER encoding instructions. You can now describe a wider range of JSON data in an ASN.1 schema.

The DER/CER/CXER/COER encoders now automatically convert any valid value of GeneralizedTime and UTCTime types to the canonical form specified by X.690 Clause 11.7 and 11.8. Previously it was assumed that the value to be encoded already satisfied the restrictions imposed on its encoding by these clauses. For example, the UTCTime value "171231235900Z" was accepted but "17122359Z" was rejected because the seconds component was absent.


What's New in ASN.1/C 10.5

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.5.

New Features

Conformance to Draft ITU-T Recommendation X.jsoner

The ASN.1/C compiler and the SOED, TOED, and LED runtime libraries support the JSON Encoding Rules. The existing -json command-line option instructs the compiler to enable support for X.jsoner at runtime.

The JSON codec supports the following encoding instructions:

  • JER:ARRAY
  • JER:BASE64
  • JER:NAME
  • JER:OBJECT
  • JER:TEXT
  • JER:UNWRAPPED
Smaller TOED footprint

By defining OSS_REDUCED_ERROR_MSGS when compiling the generated .c, error messages will contain just the 5 character message prefix, instead of the full message. Alternatively, if OSSDEBUG=0 is defined, the error message strings will be removed completely, leaving only the return code to determine which error occurred. On Linux x86, you can reduce the footprint of your application by approximately 20 kilobytes. This number may vary depending on the processor, operating system, and C compiler.

New samples

The following samples have been added for the LTE protocols:


What's New in ASN.1/C 10.4

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.4.

New Features

64-bit precision in TIME type fractions

The ASN.1/C Compiler and Runtime now support 64-bit precision (19-20 decimal digits) in TIME type fractions.

New samples

The its_sae_j2735_2016 sample for the 2016-03 version of the J2735 protocol has been created. The sample does not include the J2735:2016 ASN.1 specification due to licensing reasons. Users should obtain it directly from the ITS SAE site.

A sample for the 3GPP XwAP (TS 36.463) protocol has been created.

Improvements

For ISO 8601 TIME type values with a property settings constraint that specifies "Basic=Date" and "Date=Y", "Date=YM", or "Date=YMD", with no Year settings:

  • The ASN.1/C Compiler now correctly generates an SOED control table and TOED functions.
  • The SOED/LEAN Octet Encoding Rules (OER) encoder/decoder now correctly encodes/decodes such values.

Previously, the OER encoder produced a verbose encoding instead of an optimized binary encoding.

The name of the OSS_ALLOW_ABSENT_OR_BAD_SECONDS_OR_ABSENT_Z runtime compatibility flag has been changed to OSS_ALLOW_ABSENT_OR_BAD_SECONDS; the original name was deemed somewhat misleading. For backward compatibility, the previous name is still available.

The ASN.1/C SOED/LEAN/TOED PER encoder-decoder implementation now conforms to the recent X.691 corrigendum (2015): an encoding contained in a BIT STRING should be at least one octet for PER ALIGNED and 1 bit for PER UNALIGNED.

OER encoding of untagged CHOICE values is now aligned with the X.696 standard. Previously, such CHOICE values were encoded BER-style: the outermost tag of the chosen alternative was encoded only once.

The ASN.1/C runtime implementations are now aligned to conform to ITU-T X.680 Clause 46.3c. This clause states that the minutes component of a GeneralizedTime type value can be omitted when the difference between local time and UTC is an integral number of hours. Previously, a false error could be issued when the minutes component was absent.


What's New in ASN.1/C 10.3

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.3.

New Features

The following new features have been added:

Support for the JSON Encoding Rules

Support for the JSON Encoding Rules is available in all three runtime libraries of the OSS ASN.1/C Tools: Space-Optimized Encoder/Decoder (SOED), Time-Optimized Encoder/Decoder (TOED), and Lean Encoder/Decoder (LED). With JSON, you can preserve the power of text (JSON) encodings, yet take advantage of the conversion to or from binary (ASN.1) encodings for fast transmission or compact storage.

New command-line option

The -json command-line option enables generation of code for JSON.

New API functions

The ossBinary2JSON() and ossJSON2Binary() API functions have been added to convert data encoded in ASN.1 binary form (e.g., BER, PER, DER, OER, etc.) to JSON text encoding form (JSON) and vice versa.

The ossPrintJSON() API function is now supported. This function allows you to print the contents of a JSON encoding in a well-formatted manner.

Also, the following API functions have been added:

New IAAPI functions

The ossDetectCDRHeaders() IAAPI function accepts the input buffer with BER-based encoded messages and returns information stored in CDR headers when a supported format is detected.

The following IAAPI functions for converting to and from CSV have been added:

  • ossClearCsvSettings()
  • ossGetCsvSetting()
  • ossSetCsvSetting()
  • ossSetDefaultCsvSettings()
  • ossConvertCsvToPduValue()
  • ossConvertCsvToTypeValue()
  • ossConvertPduValueToCsv()
  • ossConvertTypeValueToCsv()
  • ossGetNumberOfExtraCsvs()
New IAAPI flag

The TLV_NOCDRHEADERS IAAPI flag suppresses automatic detection of CDR headers.

Improvements

IAAPI improvements

IAAPI functions that print BER-encoded messages in TLV format now automatically detect and skip CDR headers.

The following CDR formats are supported:

  • CDR files consisting of a CDR file header and CDR records with a CDR record header before each BER-based message.
  • CDR files consisting of CDR record headers that hold the record identifier in the first two octets and the record length in the next two octets.
Samples improvements

The samples for Releases 10, 11, and 12 have been updated to the latest versions of the standards. New samples for 3GPP LTE Release 13 have been added.


What's New in ASN.1/C 10.2

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.2.

New Features

The following new features have been added:

Partial Decoding

The partial decoding feature enables you to:

  • Decode preselected fields from incoming messages at a high speed.
  • Directly access the decoded field in the callback function without traversing from the top of the PDU.
  • Get the offset and length of the field encoding in a binary BER/DER/OER/COER message. It allows you to replace the value of the field directly in the binary message, if the encoding of the new value is of the same length as of the previous one.

The partial decoding feature requires TOED runtime version 10.2 or later and it is available upon request. For information about purchasing the license, contact Sales <info@oss.com>.

For more information, see the Partial Decoding section.

New command-line options

The -enablePartialDecode and -partialDecodeOnly options instruct the compiler to generate code that enables the ossPartialDecode() TOED runtime API function. The options are available if the -toed option is specified or implied by default.

New compiler directives

The OSS.DataCallback and OSS.InfoCallback compiler directives have been added.

New API functions

The ossPartialDecode() and ossTestPD() API functions have been added.

The following API utility functions that support BCD and TBCD encodings have been added to the ASN.1/C runtime libraries. The functions print octet-aligned data as BCD or TBCD strings and convert octet strings to or from BCD or TBCD strings.

  • ossPrintOctetAsBCDString()
  • ossPrintOctetAsTBCDString()
  • ossConvertOctetToBCDString()
  • ossConvertOctetToTBCDString()
  • ossConvertBCDStringToOctet()
  • ossConvertTBCDStringToOctet()
New Samples

You can find the partial_decode and s1ap_pd_r12 samples that illustrate the partial decoding feature usage in the samples/advanced.

The provided set of samples has been updated:

  • The new standards/tap3_bin2xml sample demonstrates conversion from binary (BER) encoding to XML (XER) encoding. It uses the ASN.1 specification from the standards/tap3 sample.
  • The new standards/cam_denm sample shows you how to handle CAM and DENM messages specified by the ETSI EN 302 637-2, ETSI EN 302 637-3, and ETSI TS 102 894-2 standards.
  • The LTE samples for 3GPP Release 12 (RRC, S1AP, X2AP, M2AP M3AP, SbcAP) have been added.

Improvements

The ossCreateUnencodedValueOfPDU() and ossCreateUnencodedValueOfType() IAAPI functions now create unencoded values for PDU types that have a CONTAINING clause inside ASN.1 types with ContentsConstraint.


What's New in ASN.1/C 10.1

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.1.

New Features

Enhanced OER Support

The ASN.1/C compiler and the TOED, SOED, and LED runtimes have all been augmented to support OER as defined in "Rec. ITU-T X.696 | ISO/IEC 8825-7", rather than only the subset of ASN.1 types as defined in the "NTCIP 1102:2004 Octet Encoding Rules (OER) Base Protocol" document.

The Canonical Octet Encoding Rules (COER) as defined in "Rec. ITU-T X.696 | ISO/IEC 8825-7" are now supported by the ASN.1/C compiler and the TOED, SOED, and LED runtimes.

Support for non-breaking spaces in the input ASN.1 syntax as UTF-8 format Unicode characters. Other Unicode characters that are treated as spaces are supported in UTF-8 format as well.

New command-line options

The new -useQualifiedNames compiler option instructs the ASN.1 compiler to add a prefix, depending on the type name, to:

  • enumerators generated for an ENUMERATED ASN.1 type
  • constants generated for named numbers of an INTEGER type
  • constants generated for named bits of a BIT STRING type

Improvements

The ASN.1/C compiler now generates huge values of base 2 REAL types without losing precision.

Choice alternatives containing an untagged choice are now canonically ordered correctly by the compiler.

The ASN.1/C compiler is changed so as to now accept GeneralizedTime values where the minutes and seconds components are omitted and a time difference component is present.

The compiler now accepts comments within compiler command files. The "--" characters specify the beginning of a comment and can be placed anywhere on the line. The comment continues until either a subsequent "--" is reached or the line ends.


What's New in ASN.1/C 10.0

This section provides a summary of the new and enhanced features in the OSS ASN.1 Tools for C 10.0.

New Features

Octet Encoding Rules (OER) Support

Support for the Octet Encoding Rules (OER), as specified by the NTCIP 1102:2004 Octet Encoding Rules (OER) Base Protocol document, has been implemented in the ASN.1/C compiler, the SOED, TOED, and IAAPI runtime libraries, ASN.1 Studio, and CAGL.

OER messages can generally be encoded/decoded significantly faster compared to BER and PER messages, while being only slightly less compact than PER messages. Support for OER in ASN.1/C LED will be provided in the next release.

New utility API functions

Two new utility API functions are provided:

  • ossPrintPDUToBuffer() serializes the content of the compiler-generated structures (before encoding or after decoding) into standard ASN.1 value notation format and then writes it into the output buffer; this function is similar to ossPrintPDU(), which writes to the standard output.
  • ossDeterminePDUBufferLength() is used to determine the length of the output buffer (in bytes) required by ossPrintPDUToBuffer().
New samples

The set of samples provided includes new samples illustrating the use of protocols based on the SAE J2735 Intelligent Transportation standard, as well as the RRC, S1AP, and X2AP LTE protocols based on 3GPP Release 10.

Improvements

You can now decode open types with table (component relation) constraints, without setting the AUTOMATIC_ENCDEC runtime flag.

The compiler will now generate TOED decoding functions so that even when the AUTOMATIC_ENCDEC runtime flag is not set, the decoder resolves component relation constraints and sets the pduNum field of the OpenType structure accordingly. The field is set to zero when neither the -autoencdec nor the -constr compiler options are specified, or when the NOCONSTRAIN runtime flag is set.

The SOED decoders will now fill in an OpenType pduNum field unless the NOCONSTRAIN runtime flag is set. Previously, the decoders did not fill in the pduNum field for new (union based) OpenTypes when the AUTOMATIC_ENCDEC flag was not set.

The compiler will now implicitly turn on the -debug option while generating TOED functions even when the -lean option is specified. Previously, the -lean option suppressed the implicit -debug option. As a result, the TOED printing functions were not generated unless -debug was specified explicitly.

Some OSS API functions (ossDecode(), ossEncode(), ossSkipPadBytes(), ossBinary2XML(), ossXML2Binary(), etc.) will now return new error codes and messages when file/socket memory manager errors occur. Previously, most such errors produced the common FATAL_ERROR (18) error code and an error message such as "x0087S: Undefined memory-management error #N.". To check for a specific error you had to parse the message and extract the #N value.


This documentation applies to the OSS® ASN.1 Tools for C release 10.7 and later.

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