Reading ASN.1 Data

Functions for reasing ASN.1 data back into C structs. More...

Collaboration diagram for Reading ASN.1 Data:

Functions
int16_t	asn_read_short (const uint8_t *asn_buffer, int32_t idx) SECTION_ASN
	Read short object in asn_buffer.
int16_t	asn_read_int (uint8_t *int_buffer, uint8_t buffer_sz, uint8_t flags, const uint8_t *asn_buffer, int32_t idx) SECTION_ASN
	Read int object in asn_buffer into buffer.
int16_t	asn_read_string (char *str_buffer, int16_t str_buffer_sz, const uint8_t *asn_buffer, int32_t idx) SECTION_ASN
	Read string object in asn_buffer into str_buffer.
int16_t	asn_read_meta_ptr (const uint8_t *buffer, int32_t idx, uint8_t *type_out, int32_t *sz_out) SECTION_ASN
	Get metadata for the object at idx in buffer.

Detailed Description

Functions for reasing ASN.1 data back into C structs.

These functions generally take a locked MEMORY_PTR to the ASN.1 data. This may seem inconsistent with Writing ASN.1 Data, but since the ASN.1 buffer is finalized and won't change size, locking the buffer once and passing it around is faster and simpler.

Function Documentation

asn_read_int()

int16_t asn_read_int	(	uint8_t *	int_buffer,
		uint8_t	buffer_sz,
		uint8_t	flags,
		const uint8_t *	asn_buffer,
		int32_t	idx
	)

Read int object in asn_buffer into buffer.

Parameters

int_buffer	Buffer in which to place parsed integer.
buffer_sz	Size of output integer buffer in bytes.
flags	ASN.1 Function Flags to alter function behavior.
asn_buffer	Buffer containing ASN data to parse.
idx	Index of integer object (starting at type byte) in asn_buffer.

Returns

Count of bytes parsed in asn_buffer or ASN.1 Error Codes.

asn_read_meta_ptr()

int16_t asn_read_meta_ptr	(	const uint8_t *	buffer,
		int32_t	idx,
		uint8_t *	type_out,
		int32_t *	sz_out
	)

Get metadata for the object at idx in buffer.

Parameters

buffer
idx
type_out
sz_out

Returns

asn_read_short()

int16_t asn_read_short	(	const uint8_t *	asn_buffer,
		int32_t	idx
	)

Read short object in asn_buffer.

Parameters

int_buffer	Buffer in which to place parsed integer.
asn_buffer	Buffer containing ASN data to parse.
idx	Index of integer object (starting at type byte) in asn_buffer.

Returns

Count of bytes parsed in asn_buffer or ASN.1 Error Codes.

Deprecated:

Should be worked into asn_read_int using flags at some point.

asn_read_string()

int16_t asn_read_string	(	char *	str_buffer,
		int16_t	str_buffer_sz,
		const uint8_t *	asn_buffer,
		int32_t	idx
	)

Read string object in asn_buffer into str_buffer.

Parameters

str_buffer	Buffer in which to place parsed string.
str_buffer_sz	Size of output string buffer in bytes.
asn_buffer	Buffer containing ASN data to parse.
idx	Index of string object (starting at type byte) in asn_buffer.

Returns

Count of bytes parsed in asn_buffer or ASN.1 Error Codes.