# asn1rt

### MODULE

asn1rt

### MODULE SUMMARY

ASN.1 runtime support functions

### DESCRIPTION

This module is the interface module for the ASN.1 runtime support functions. To encode and decode ASN.1 types in runtime the functions in this module should be used.

### EXPORTS

`encode(Module,Type,Value)-> {ok,BinOrList} | {error,Reason}`

Types:

`Module = Type = atom()`
`Value = term()`
`BinOrList = Bytes | binary()`
`Bytes = [Int|binary|Bytes] when integer(Int), Int >= 0, Int =< 255`
`Reason = term()`

Encodes `Value` of `Type` defined in the ASN.1 module `Module`. Returns a possibly nested list of bytes and or binaries if successful. If `Module` was compiled with the options `per_bin` and `optimize` the result is a binary. To get as fast execution as possible the encode function only performs rudimentary tests that the input `Value` is a correct instance of `Type`. The length of strings is for example not always checked.

`decode(Module,Type,Bytes) -> {ok,Value}|{error,Reason}`

Types:

`Module = Type = atom()`
`Value = Reason = term()`
`Bytes = binary | [Int] when integer(Int), Int >= 0, Int =< 255 | binary`

Decodes `Type` from `Module` from the list of bytes or binary `Bytes`. If the module is compiled with `ber_bin` or `per_bin` option `Bytes` must be a binary. Returns `{ok,Value}` if successful.

`validate(Module,Type,Value) -> ok | {error,Reason}`

Types:

`Module = Type = atom()`
`Value = term()`

Validates that `Value` conforms to `Type` from `Module`. Not implemented in this version of the ASN.1 application.

`load_driver() -> ok | {error,Reason}`

Types:

`Reason = term()`

This function loads the linked-in driver before the first call to encode. If this function is not called the driver will be loaded automatically at the first call to encode. If one doesn't want the performance cost of a driver load when the application is running, this function makes it possible to load the driver in an initialization.

The driver is only used when encoding/decoding ASN.1 files that were compiled with the options `per_bin` and `optimize`.

`unload_driver() -> ok | {error,Reason}`

Types:

`Reason = term()`

This function unloads the linked-in driver. When the driver has been loaded it remains in the environment until it is unloaded. Normally the driver should remain loaded, it is crucial for the performance of ASN.1 encoding.

The driver is only used when ASN.1 modules have been compiled with the flags `per_bin` and `optimize`.

`info(Module) -> {ok,Info} | {error,Reason}`

Types:

`Module = atom()`
`Info = list()`
`Reason = term()`

`info/1` returns the version of the asn1 compiler that was used to comile the module. It also returns the compiler options that was used.

`utf8_binary_to_list(UTF8Binary) -> {ok,UnicodeList} | {error,Reason}`

Types:

`UTF8Binary = binary()`
`UnicodeList = [integer()]`
`Reason = term()`

`utf8_binary_to_list/1` Transforms a UTF8 encoded binary to a list of integers, where each integer represents one character as its unicode value. The function fails if the binary is not a properly encoded UTF8 string.

`utf8_list_to_binary(UnicodeList) -> {ok,UTF8Binary} | {error,Reason}`

Types:

`UnicodeList = [integer()]`
`UTF8Binary = binary()`
`Reason = term()`

`utf8_list_to_binary/1` Transforms a list of integers, where each integer represents one character as its unicode value, to a UTF8 encoded binary.

### AUTHORS

Kenneth Lundin - support@erlang.ericsson.se
Bertil Karlsson - support@erlang.ericsson.se

asn1 1.4.4.12
Copyright © 1991-2007 Ericsson AB