void asn1_length_der (unsigned long int len, unsigned char * der, int * der_len) ¶len: value to convert.
der: buffer to hold the returned encoding (may be NULL ).
der_len: number of meaningful bytes of ANS (der[0]..der[der_len-1]).
Creates the DER encoding of the provided length value.
The der buffer must have enough room for the output. The maximum
length this function will encode is ASN1_MAX_LENGTH_SIZE .
To know the size of the DER encoding use a NULL value for der .
void asn1_octet_der (const unsigned char * str, int str_len, unsigned char * der, int * der_len) ¶str: the input data.
str_len: STR length (str[0]..str[*str_len-1]).
der: encoded string returned.
der_len: number of meaningful bytes of DER (der[0]..der[der_len-1]).
Creates a length-value DER encoding for the input data.
The DER encoding of the input data will be placed in the der variable.
Note that the OCTET STRING tag is not included in the output.
This function does not return any value because it is expected
that der_len will contain enough bytes to store the string
plus the DER encoding. The DER encoding size can be obtained using
asn1_length_der() .
int asn1_encode_simple_der (unsigned int etype, const unsigned char * str, unsigned int str_len, unsigned char * tl, unsigned int * tl_len) ¶etype: The type of the string to be encoded (ASN1_ETYPE_)
str: the string data.
str_len: the string length
tl: the encoded tag and length
tl_len: the bytes of the tl field
Creates the DER encoding for various simple ASN.1 types like strings etc.
It stores the tag and length in tl , which should have space for at least
ASN1_MAX_TL_SIZE bytes. Initially tl_len should contain the size of tl .
The complete DER encoding should consist of the value in tl appended
with the provided str .
Returns: ASN1_SUCCESS if successful or an error value.
int asn1_object_id_der (const char * str, unsigned char * der, int * der_len, unsigned flags) ¶str: An object identifier in numeric, dot format.
der: buffer to hold the returned encoding (may be NULL ).
der_len: initially the size of der ; will hold the final size.
flags: must be zero
Creates the DER encoding of the provided object identifier.
Returns: ASN1_SUCCESS if DER encoding was OK, ASN1_VALUE_NOT_VALID
if str is not a valid OID, ASN1_MEM_ERROR if the der vector isn’t big enough and in this case der_len will contain the
length needed.
void asn1_bit_der (const unsigned char * str, int bit_len, unsigned char * der, int * der_len) ¶str: BIT string.
bit_len: number of meaningful bits in STR.
der: string returned.
der_len: number of meaningful bytes of DER (der[0]..der[ans_len-1]).
Creates a length-value DER encoding for the input data
as it would have been for a BIT STRING.
The DER encoded data will be copied in der .
Note that the BIT STRING tag is not included in the output.
This function does not return any value because it is expected
that der_len will contain enough bytes to store the string
plus the DER encoding. The DER encoding size can be obtained using
asn1_length_der() .
int asn1_der_coding (asn1_node_const element, const char * name, void * ider, int * len, char * ErrorDescription) ¶element: pointer to an ASN1 element
name: the name of the structure you want to encode (it must be inside *POINTER).
ider: vector that will contain the DER encoding. DER must be a pointer to memory cells already allocated.
len: number of bytes of * ider : ider [0].. ider [len-1], Initially
holds the sizeof of der vector.
ErrorDescription: return the error description or an empty string if success.
Creates the DER encoding for the NAME structure (inside *POINTER structure).
Returns: ASN1_SUCCESS if DER encoding OK, ASN1_ELEMENT_NOT_FOUND
if name is not a valid element, ASN1_VALUE_NOT_FOUND if there
is an element without a value, ASN1_MEM_ERROR if the ider vector isn’t big enough and in this case len will contain the
length needed.
long asn1_get_length_der (const unsigned char * der, int der_len, int * len) ¶der: DER data to decode.
der_len: Length of DER data to decode.
len: Output variable containing the length of the DER length field.
Extract a length field from DER data.
Returns: Return the decoded length value, or -1 on indefinite
length, or -2 when the value was too big to fit in a int, or -4
when the decoded length value plus len would exceed der_len .
int asn1_get_tag_der (const unsigned char * der, int der_len, unsigned char * cls, int * len, unsigned long * tag) ¶der: DER data to decode.
der_len: Length of DER data to decode.
cls: Output variable containing decoded class.
len: Output variable containing the length of the DER TAG data.
tag: Output variable containing the decoded tag (may be NULL ).
Decode the class and TAG from DER code.
Returns: Returns ASN1_SUCCESS on success, or an error.
long asn1_get_length_ber (const unsigned char * ber, int ber_len, int * len) ¶ber: BER data to decode.
ber_len: Length of BER data to decode.
len: Output variable containing the length of the BER length field.
Extract a length field from BER data. The difference to
asn1_get_length_der() is that this function will return a length
even if the value has indefinite encoding.
Returns: Return the decoded length value, or negative value when the value was too big.
Since: 2.0
int asn1_get_octet_der (const unsigned char * der, int der_len, int * ret_len, unsigned char * str, int str_size, int * str_len) ¶der: DER data to decode containing the OCTET SEQUENCE.
der_len: The length of the der data to decode.
ret_len: Output variable containing the encoded length of the DER data.
str: Pre-allocated output buffer to put decoded OCTET SEQUENCE in.
str_size: Length of pre-allocated output buffer.
str_len: Output variable containing the length of the contents of the OCTET SEQUENCE.
Extract an OCTET SEQUENCE from DER data. Note that this function expects the DER data past the tag field, i.e., the length and content octets.
Returns: Returns ASN1_SUCCESS on success, or an error.
int asn1_get_object_id_der (const unsigned char * der, int der_len, int * ret_len, char * str, int str_size) ¶der: DER data to decode containing the OBJECT IDENTIFIER
der_len: Length of DER data to decode.
ret_len: Output variable containing the length of the DER data.
str: Pre-allocated output buffer to put the textual object id in.
str_size: Length of pre-allocated output buffer.
Converts a DER encoded object identifier to its textual form. This function expects the DER object identifier without the tag.
Returns: ASN1_SUCCESS on success, or an error.
int asn1_get_bit_der (const unsigned char * der, int der_len, int * ret_len, unsigned char * str, int str_size, int * bit_len) ¶der: DER data to decode containing the BIT SEQUENCE.
der_len: Length of DER data to decode.
ret_len: Output variable containing the length of the DER data.
str: Pre-allocated output buffer to put decoded BIT SEQUENCE in.
str_size: Length of pre-allocated output buffer.
bit_len: Output variable containing the size of the BIT SEQUENCE.
Extract a BIT SEQUENCE from DER data.
Returns: ASN1_SUCCESS on success, or an error.
int asn1_der_decoding2 (asn1_node * element, const void * ider, int * max_ider_len, unsigned int flags, char * errorDescription) ¶element: pointer to an ASN1 structure.
ider: vector that contains the DER encoding.
max_ider_len: pointer to an integer giving the information about the
maximal number of bytes occupied by * ider . The real size of the DER
encoding is returned through this pointer.
flags: flags controlling the behaviour of the function.
errorDescription: null-terminated string contains details when an error occurred.
Fill the structure * element with values of a DER encoding string. The
structure must just be created with function asn1_create_element() .
If ASN1_DECODE_FLAG_ALLOW_PADDING flag is set then the function will ignore
padding after the decoded DER data. Upon a successful return the value of
* max_ider_len will be set to the number of bytes decoded.
If ASN1_DECODE_FLAG_STRICT_DER flag is set then the function will
not decode any BER-encoded elements.
Returns: ASN1_SUCCESS if DER encoding OK, ASN1_ELEMENT_NOT_FOUND
if ELEMENT is NULL , and ASN1_TAG_ERROR or
ASN1_DER_ERROR if the der encoding doesn’t match the structure
name (* ELEMENT deleted).
int asn1_der_decoding (asn1_node * element, const void * ider, int ider_len, char * errorDescription) ¶element: pointer to an ASN1 structure.
ider: vector that contains the DER encoding.
ider_len: number of bytes of * ider : ider [0].. ider [len-1].
errorDescription: null-terminated string contains details when an error occurred.
Fill the structure * element with values of a DER encoding
string. The structure must just be created with function
asn1_create_element() .
Note that the * element variable is provided as a pointer for
historical reasons.
Returns: ASN1_SUCCESS if DER encoding OK, ASN1_ELEMENT_NOT_FOUND
if ELEMENT is NULL , and ASN1_TAG_ERROR or
ASN1_DER_ERROR if the der encoding doesn’t match the structure
name (* ELEMENT deleted).
int asn1_der_decoding_element (asn1_node * structure, const char * elementName, const void * ider, int len, char * errorDescription) ¶structure: pointer to an ASN1 structure
elementName: name of the element to fill
ider: vector that contains the DER encoding of the whole structure.
len: number of bytes of *der: der[0]..der[len-1]
errorDescription: null-terminated string contains details when an error occurred.
Fill the element named ELEMENTNAME with values of a DER encoding
string. The structure must just be created with function
asn1_create_element() . The DER vector must contain the encoding
string of the whole STRUCTURE . If an error occurs during the
decoding procedure, the * STRUCTURE is deleted and set equal to
NULL .
This function is deprecated and may just be an alias to asn1_der_decoding
in future versions. Use asn1_der_decoding() instead.
Returns: ASN1_SUCCESS if DER encoding OK, ASN1_ELEMENT_NOT_FOUND
if ELEMENT is NULL or elementName == NULL, and
ASN1_TAG_ERROR or ASN1_DER_ERROR if the der encoding doesn’t
match the structure structure (*ELEMENT deleted).
int asn1_der_decoding_startEnd (asn1_node element, const void * ider, int ider_len, const char * name_element, int * start, int * end) ¶element: pointer to an ASN1 element
ider: vector that contains the DER encoding.
ider_len: number of bytes of * ider : ider [0].. ider [len-1]
name_element: an element of NAME structure.
start: the position of the first byte of NAME_ELEMENT decoding
( ider [*start])
end: the position of the last byte of NAME_ELEMENT decoding
( ider [*end])
Find the start and end point of an element in a DER encoding
string. I mean that if you have a der encoding and you have already
used the function asn1_der_decoding() to fill a structure, it may
happen that you want to find the piece of string concerning an
element of the structure.
One example is the sequence "tbsCertificate" inside an X509 certificate.
Note that since libtasn1 3.7 the ider and ider_len parameters
can be omitted, if the element is already decoded using asn1_der_decoding() .
Returns: ASN1_SUCCESS if DER encoding OK, ASN1_ELEMENT_NOT_FOUND
if ELEMENT is asn1_node EMPTY or name_element is not a valid
element, ASN1_TAG_ERROR or ASN1_DER_ERROR if the der encoding
doesn’t match the structure ELEMENT.
int asn1_expand_any_defined_by (asn1_node_const definitions, asn1_node * element) ¶definitions: ASN1 definitions
element: pointer to an ASN1 structure
Expands every "ANY DEFINED BY" element of a structure created from a DER decoding process (asn1_der_decoding function). The element ANY must be defined by an OBJECT IDENTIFIER. The type used to expand the element ANY is the first one following the definition of the actual value of the OBJECT IDENTIFIER.
Returns: ASN1_SUCCESS if Substitution OK, ASN1_ERROR_TYPE_ANY if
some "ANY DEFINED BY" element couldn’t be expanded due to a
problem in OBJECT_ID -> TYPE association, or other error codes
depending on DER decoding.
int asn1_expand_octet_string (asn1_node_const definitions, asn1_node * element, const char * octetName, const char * objectName) ¶definitions: ASN1 definitions
element: pointer to an ASN1 structure
octetName: name of the OCTET STRING field to expand.
objectName: name of the OBJECT IDENTIFIER field to use to define the type for expansion.
Expands an "OCTET STRING" element of a structure created from a DER
decoding process (the asn1_der_decoding() function). The type used
for expansion is the first one following the definition of the
actual value of the OBJECT IDENTIFIER indicated by OBJECTNAME.
Returns: ASN1_SUCCESS if substitution OK, ASN1_ELEMENT_NOT_FOUND
if objectName or octetName are not correct,
ASN1_VALUE_NOT_VALID if it wasn’t possible to find the type to
use for expansion, or other errors depending on DER decoding.
int asn1_decode_simple_der (unsigned int etype, const unsigned char * der, unsigned int _der_len, const unsigned char ** str, unsigned int * str_len) ¶etype: The type of the string to be encoded (ASN1_ETYPE_)
der: the encoded string
_der_len: the bytes of the encoded string
str: a pointer to the data
str_len: the length of the data
Decodes a simple DER encoded type (e.g. a string, which is not constructed).
The output is a pointer inside the der .
Returns: ASN1_SUCCESS if successful or an error value.
int asn1_decode_simple_ber (unsigned int etype, const unsigned char * der, unsigned int _der_len, unsigned char ** str, unsigned int * str_len, unsigned int * ber_len) ¶etype: The type of the string to be encoded (ASN1_ETYPE_)
der: the encoded string
_der_len: the bytes of the encoded string
str: a pointer to the data
str_len: the length of the data
ber_len: the total length occupied by BER (may be NULL )
Decodes a BER encoded type. The output is an allocated value of the data. This decodes BER STRINGS only. Other types are decoded as DER.
Returns: ASN1_SUCCESS if successful or an error value.