ASN.1/C Web Compiler

Features	Full Codec with Validation	Compact Codec
ASN.1 Features Support	Complete	Few Restrictions i No support for CHARACTER STRING, EMBEDDED-PDV, EXTERNAL, INSTANCE OF, and the TIME type and its subtypes.
Binary Encoding Rules	all	all
Text Encoding Rules	JER (JSON)	✗
CHOICE type with untagged alternatives	✓	✗
SEQUENCE/SET with a complex DEFAULT	✓	✗ i Such DEFAULTs are not ignored, the user must take responsibility to ensure that no values matching the defaults will be presented to the Encode function of the canonical encoding rules, otherwise this may result in non-canonical encodings.
Recursive type definition in schemas	✓	✓
Automatic encoding/decoding of OCTET STRING and BIT STRING with a contents constraint	✓	✓
Automatic decoding constrained open types	✓	✓ i Limited to only one referenced component of the same SEQUENCE or SET type and the reference is INTEGER or OBJECT IDENTIFIER.
Validation of an ASN.1 value	✓	✗
Copying, comparison of ASN.1 values	✓	✗
Get PDU id by type name	✓	✗
Detailed errors	✓ i Multiple errors, including the position of the field. E.g. Error 80002: The end of the encoding was encountered inside the content; check the content (INTEGER type 'I') of field 'cc' (OCTET STRING type 'OI') of PDU (SEQUENCE type 'CC-INT')	✗ i Single error with an error code and a short description. E.g. Error 401: The input value is invalid and cannot be encoded
Support for standard malloc/free	✓	✓
Support for custom malloc/free	✓	✓
Support for the 'Black Hole' allocator i The 'Black Hole' allocator extracts contiguous memory blocks from a preallocated buffer and never re-uses those blocks.	✓	✓

General options

Codec choice: ⓘ

Allow encoding of complex DEFAULTs Ignore complex DEFAULTs (for types other than NULL, BOOLEAN, ENUMERATED, INTEGER and BIT STRING) during encoding. Warning: for canonical ER, it might produce non-conformant encodings, as complex DEFAULT values will still be encoded.

Always decode the Open Types Decode Open Types even when their IDs are nested at a different level. Otherwise Open Types can be decoded in a separate step.

Encoding rule:

Include JER (useful for debugging)

Text and binary formats, where OER is faster, PER is smaller, JER is human readable, etc.

Code generation

Codec name: The name is incorporated in public generated names.

Generate sample

Type or Value name for the sample:

Generate functions:

Generate codec for PDU(s): List of space-delimited type names (TypeName or ModuleName.TypeName or *.TypeName), to be included in the generated code, along with all their dependencies. By default, all the types defined in the schema are included.

Namespace prefix: Useful to distinguish multiple compilations for different schemas and/or encoding rules.

Data binding

BigIntegers Generates a BigInteger to accommodate unconstrained integers (instead of 64-bit values).

BigReals Generates a BigReal for REAL (instead of "double").

BigOIDs Generates unconstrained OID arcs (instead of 64-bit values).

Platform options

Platform: Inquire about ARM, MIPS, PowerPC, and other bare or embedded platforms. Email us your platform specs at asn1io@oss.com

Memory management

BlackHole All memory allocations are made out of a single buffer provided by the user MallocFree All memory allocations are made by calling the malloc/free functions defined in the standard C library Custom MallocFree All memory allocations by generating malloc/free style function calls (see below). The functions to be called must be defined in the user application and declared in a header file named "custom.h"

Malloc function name:

Free function name:

Type names

Built in / Keywords No use of type names for 64-bit integer types; use the built-in types “long long” and “unsigned long long” as such
Standard The type names to be used are those defined in the standard header file stdint.h (normally "int64_t" and "uint64_t").
Custom Alternative type names to refer to the built-in 64-bit integer types instead of using keywords such as "long long" (see below). The type names to be used must be declared in a header file named "custom.h"

SignedInt64TypeName:

UnsignedInt64TypeName:

Advanced options

Shorten public identifiers Ensures that the names of all types, fields, and functions in the API are no longer than 31 characters.

Code footprint reduction

Exclude types: List of space-delimited type names (TypeName or ModuleName.TypeName or *.TypeName) for optional components of a SEQUENCE or alternatives of a CHOICE that are not expected to be present in a message and can be excluded from the generated code.