Generic ASN.1 parsing. More...

Data Structures
struct	mbedtls_asn1_buf
	Type-length-value structure that allows for ASN1 using DER. More...
struct	mbedtls_asn1_bitstring
	Container for ASN1 bit strings. More...
struct	mbedtls_asn1_sequence
	Container for a sequence of ASN.1 items. More...
struct	mbedtls_asn1_named_data
	Container for a sequence or list of 'named' ASN.1 data items. More...
Functions to parse ASN.1 data structures
typedef struct mbedtls_asn1_buf	mbedtls_asn1_buf
	Type-length-value structure that allows for ASN1 using DER.
typedef struct mbedtls_asn1_bitstring	mbedtls_asn1_bitstring
	Container for ASN1 bit strings.
typedef struct mbedtls_asn1_sequence	mbedtls_asn1_sequence
	Container for a sequence of ASN.1 items.
typedef struct mbedtls_asn1_named_data	mbedtls_asn1_named_data
	Container for a sequence or list of 'named' ASN.1 data items.
int	mbedtls_asn1_get_len (unsigned char *p, const unsigned char end, size_t *len)
	Get the length of an ASN.1 element.
int	mbedtls_asn1_get_tag (unsigned char *p, const unsigned char end, size_t *len, int tag)
	Get the tag and length of the element.
int	mbedtls_asn1_get_bool (unsigned char *p, const unsigned char end, int *val)
	Retrieve a boolean ASN.1 tag and its value.
int	mbedtls_asn1_get_int (unsigned char *p, const unsigned char end, int *val)
	Retrieve an integer ASN.1 tag and its value.
int	mbedtls_asn1_get_bitstring (unsigned char *p, const unsigned char end, mbedtls_asn1_bitstring *bs)
	Retrieve a bitstring ASN.1 tag and its value.
int	mbedtls_asn1_get_bitstring_null (unsigned char *p, const unsigned char end, size_t *len)
	Retrieve a bitstring ASN.1 tag without unused bits and its value.
int	mbedtls_asn1_get_sequence_of (unsigned char *p, const unsigned char end, mbedtls_asn1_sequence *cur, int tag)
	Parses and splits an ASN.1 "SEQUENCE OF <tag>".
int	mbedtls_asn1_get_mpi (unsigned char *p, const unsigned char end, mbedtls_mpi *X)
	Retrieve an integer ASN.1 tag and its value.
int	mbedtls_asn1_get_alg (unsigned char *p, const unsigned char end, mbedtls_asn1_buf alg, mbedtls_asn1_buf params)
	Retrieve an AlgorithmIdentifier ASN.1 sequence.
int	mbedtls_asn1_get_alg_null (unsigned char *p, const unsigned char end, mbedtls_asn1_buf *alg)
	Retrieve an AlgorithmIdentifier ASN.1 sequence with NULL or no params.
mbedtls_asn1_named_data *	mbedtls_asn1_find_named_data (mbedtls_asn1_named_data list, const char oid, size_t len)
	Find a specific named_data entry in a sequence or list based on the OID.
void	mbedtls_asn1_free_named_data (mbedtls_asn1_named_data *entry)
	Free a mbedtls_asn1_named_data entry.
void	mbedtls_asn1_free_named_data_list (mbedtls_asn1_named_data **head)
	Free all entries in a mbedtls_asn1_named_data list.

Detailed Description

Generic ASN.1 parsing.

Definition in file asn1.h.

Typedef Documentation

typedef struct mbedtls_asn1_bitstring mbedtls_asn1_bitstring

Container for ASN1 bit strings.

typedef struct mbedtls_asn1_buf mbedtls_asn1_buf

Type-length-value structure that allows for ASN1 using DER.

typedef struct mbedtls_asn1_named_data mbedtls_asn1_named_data

Container for a sequence or list of 'named' ASN.1 data items.

typedef struct mbedtls_asn1_sequence mbedtls_asn1_sequence

Container for a sequence of ASN.1 items.

Function Documentation

mbedtls_asn1_named_data* mbedtls_asn1_find_named_data	(	mbedtls_asn1_named_data *	list,
		const char *	oid,
		size_t	len
	)

Find a specific named_data entry in a sequence or list based on the OID.

Parameters:

list	The list to seek through
oid	The OID to look for
len	Size of the OID

Returns:: NULL if not found, or a pointer to the existing entry.

Definition at line 394 of file asn1parse.c.

void mbedtls_asn1_free_named_data ( mbedtls_asn1_named_data * entry )

Free a mbedtls_asn1_named_data entry.

Parameters:

entry The named data entry to free. This function calls mbedtls_free() on `entry->oid.p` and `entry->val.p`.

Definition at line 371 of file asn1parse.c.

void mbedtls_asn1_free_named_data_list ( mbedtls_asn1_named_data ** head )

Free all entries in a mbedtls_asn1_named_data list.

Parameters:

head	Pointer to the head of the list of named data entries to free. This function calls mbedtls_asn1_free_named_data() and mbedtls_free() on each list element and sets `*head` to `NULL`.

Definition at line 382 of file asn1parse.c.

int mbedtls_asn1_get_alg	(	unsigned char **	p,
		const unsigned char *	end,
		mbedtls_asn1_buf *	alg,
		mbedtls_asn1_buf *	params
	)

Retrieve an AlgorithmIdentifier ASN.1 sequence.

Updates the pointer to immediately behind the full AlgorithmIdentifier.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` points to the first byte beyond the AlgorithmIdentifier element. On error, the value of `*p` is undefined.
end	End of data.
alg	The buffer to receive the OID.
params	The buffer to receive the parameters. This is zeroized if there are no parameters.

Returns:: 0 if successful or a specific ASN.1 or MPI error code.

Definition at line 309 of file asn1parse.c.

int mbedtls_asn1_get_alg_null	(	unsigned char **	p,
		const unsigned char *	end,
		mbedtls_asn1_buf *	alg
	)

Retrieve an AlgorithmIdentifier ASN.1 sequence with NULL or no params.

Updates the pointer to immediately behind the full AlgorithmIdentifier.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` points to the first byte beyond the AlgorithmIdentifier element. On error, the value of `*p` is undefined.
end	End of data.
alg	The buffer to receive the OID.

Returns:: 0 if successful or a specific ASN.1 or MPI error code.

Definition at line 353 of file asn1parse.c.

int mbedtls_asn1_get_bitstring	(	unsigned char **	p,
		const unsigned char *	end,
		mbedtls_asn1_bitstring *	bs
	)

Retrieve a bitstring ASN.1 tag and its value.

Updates the pointer to immediately behind the full tag.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` is equal to `end`. On error, the value of `*p` is undefined.
end	End of data.
bs	On success, mbedtls_asn1_bitstring information about the parsed value.

Returns:: 0 if successful.; MBEDTLS_ERR_ASN1_LENGTH_MISMATCH if the input contains extra data after a valid BIT STRING.; An ASN.1 error code if the input does not start with a valid ASN.1 BIT STRING.

Definition at line 202 of file asn1parse.c.

int mbedtls_asn1_get_bitstring_null	(	unsigned char **	p,
		const unsigned char *	end,
		size_t *	len
	)

Retrieve a bitstring ASN.1 tag without unused bits and its value.

Updates the pointer to the beginning of the bit/octet string.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` points to the first byte of the content of the BIT STRING. On error, the value of `*p` is undefined.
end	End of data.
len	On success, `*len` is the length of the content in bytes.

Returns:: 0 if successful.; MBEDTLS_ERR_ASN1_INVALID_DATA if the input starts with a valid BIT STRING with a nonzero number of unused bits.; An ASN.1 error code if the input does not start with a valid ASN.1 BIT STRING.

Definition at line 235 of file asn1parse.c.

int mbedtls_asn1_get_bool	(	unsigned char **	p,
		const unsigned char *	end,
		int *	val
	)

Retrieve a boolean ASN.1 tag and its value.

Updates the pointer to immediately behind the full tag.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` points to the first byte beyond the ASN.1 element. On error, the value of `*p` is undefined.
end	End of data.
val	On success, the parsed value (`0` or `1`).

Returns:: 0 if successful.; An ASN.1 error code if the input does not start with a valid ASN.1 BOOLEAN.

Definition at line 123 of file asn1parse.c.

int mbedtls_asn1_get_int	(	unsigned char **	p,
		const unsigned char *	end,
		int *	val
	)

Retrieve an integer ASN.1 tag and its value.

Updates the pointer to immediately behind the full tag.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` points to the first byte beyond the ASN.1 element. On error, the value of `*p` is undefined.
end	End of data.
val	On success, the parsed value.

Returns:: 0 if successful.; An ASN.1 error code if the input does not start with a valid ASN.1 INTEGER.; MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does not fit in an int.; An ASN.1 error code if the input does not start with a valid ASN.1 INTEGER.

Definition at line 142 of file asn1parse.c.

int mbedtls_asn1_get_len	(	unsigned char **	p,
		const unsigned char *	end,
		size_t *	len
	)

Get the length of an ASN.1 element.

Updates the pointer to immediately behind the length.

Parameters:

p	On entry, `p` points to the first byte of the length, i.e. immediately after the tag. On successful completion, `p` points to the first byte after the length, i.e. the first byte of the content. On error, the value of `*p` is undefined.
end	End of data.
len	On successful completion, `*len` contains the length read from the ASN.1 input.

Returns:: 0 if successful.; MBEDTLS_ERR_ASN1_OUT_OF_DATA if the ASN.1 element would end beyond end.; MBEDTLS_ERR_ASN1_INVALID_LENGTH if the length is unparseable.

Definition at line 50 of file asn1parse.c.

int mbedtls_asn1_get_mpi	(	unsigned char **	p,
		const unsigned char *	end,
		mbedtls_mpi *	X
	)

Retrieve an integer ASN.1 tag and its value.

Updates the pointer to immediately behind the full tag.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` points to the first byte beyond the ASN.1 element. On error, the value of `*p` is undefined.
end	End of data.
X	On success, the parsed value.

Returns:: 0 if successful.; An ASN.1 error code if the input does not start with a valid ASN.1 INTEGER.; MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does not fit in an int.; An MPI error code if the parsed value is too large.; An ASN.1 error code if the input does not start with a valid ASN.1 INTEGER.

Definition at line 184 of file asn1parse.c.

int mbedtls_asn1_get_sequence_of	(	unsigned char **	p,
		const unsigned char *	end,
		mbedtls_asn1_sequence *	cur,
		int	tag
	)

Parses and splits an ASN.1 "SEQUENCE OF <tag>".

Updates the pointer to immediately behind the full sequence tag.

Note:: On error, this function may return a partial list in cur. You must set `cur->next = NULL` before calling this function! Otherwise it is impossible to distinguish a previously non-null pointer from a pointer to an object allocated by this function.; If the sequence is empty, this function does not modify *cur. If the sequence is valid and non-empty, this function sets `cur->buf.tag` to tag. This allows callers to distinguish between an empty sequence and a one-element sequence.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` is equal to `end`. On error, the value of `*p` is undefined.
end	End of data.
cur	A mbedtls_asn1_sequence which this function fills. When this function returns, `cur` is the head of a linked list. Each node in this list is allocated with mbedtls_calloc() apart from `cur` itself, and should therefore be freed with mbedtls_free(). The list describes the content of the sequence. The head of the list (i.e. `cur` itself) describes the first element, `*cur->next` describes the second element, etc. For each element, `buf.tag == tag`, `buf.len` is the length of the content of the content of the element, and `buf.p` points to the first byte of the content (i.e. immediately past the length of the element). Note that list elements may be allocated even on error.
tag	Each element of the sequence must have this tag.

Returns:: 0 if successful.; MBEDTLS_ERR_ASN1_LENGTH_MISMATCH if the input contains extra data after a valid SEQUENCE OF tag.; MBEDTLS_ERR_ASN1_ALLOC_FAILED if a memory allocation failed.; An ASN.1 error code if the input does not start with a valid ASN.1 BIT STRING.

Definition at line 259 of file asn1parse.c.

int mbedtls_asn1_get_tag	(	unsigned char **	p,
		const unsigned char *	end,
		size_t *	len,
		int	tag
	)

Get the tag and length of the element.

Check for the requested tag. Updates the pointer to immediately behind the tag and length.

Parameters:

p	On entry, `p` points to the start of the ASN.1 element. On successful completion, `p` points to the first byte after the length, i.e. the first byte of the content. On error, the value of `*p` is undefined.
end	End of data.
len	On successful completion, `*len` contains the length read from the ASN.1 input.
tag	The expected tag.

Returns:: 0 if successful.; MBEDTLS_ERR_ASN1_UNEXPECTED_TAG if the data does not start with the requested tag.; MBEDTLS_ERR_ASN1_OUT_OF_DATA if the ASN.1 element would end beyond end.; MBEDTLS_ERR_ASN1_INVALID_LENGTH if the length is unparseable.

Definition at line 108 of file asn1parse.c.

Type:	Library
Created:	17 Dec 2019
Imports:	79
Forks:	0
Commits:	2
Dependents:	2
Dependencies:	0
Followers:	1

Important changes to repositories hosted on mbed.com

asn1.h File Reference

Data Structures

Functions to parse ASN.1 data structures

Detailed Description

Typedef Documentation

Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

Important changes to repositories hosted on mbed.com

asn1.h File Reference

Data Structures

Functions to parse ASN.1 data structures

Detailed Description

Typedef Documentation

Function Documentation

Repository toolbox

Repository details

Important Information for this Arm website

Access Warning