NAME
ASN1_STRING_dup, ASN1_STRING_cmp, ASN1_STRING_set, ASN1_STRING_length, ASN1_STRING_length_set, ASN1_STRING_type, ASN1_STRING_data — ASN1_STRING utility functions
Synopsis
int ASN1_STRING_length(ASN1_STRING *x);
unsigned
char * ASN1_STRING_data(ASN1_STRING *x);
ASN1_STRING *
ASN1_STRING_dup(ASN1_STRING *a);
int ASN1_STRING_cmp(ASN1_STRING
*a, ASN1_STRING *b);
int ASN1_STRING_set(ASN1_STRING *str,
const void *data, int len);
int ASN1_STRING_type(ASN1_STRING
*x);
int ASN1_STRING_to_UTF8(unsigned char **out, ASN1_STRING
*in);
DESCRIPTION
These functions allow an ASN1_STRING structure
to be manipulated.
ASN1_STRING_length() returns the length of the content of x.
ASN1_STRING_data() returns an internal pointer to the data
of x. Since this is an internal pointer it
should not be freed or modified in any way.
ASN1_STRING_dup() returns a copy of the structure a.
ASN1_STRING_cmp() compares a and b returning
0 if the two are identical. The string types and content are compared.
ASN1_STRING_set() sets the data of string str to
the buffer data or length len.
The supplied data is copied. If len is -1 then
the length is determined by strlen(data).
ASN1_STRING_type() returns the type of x,
using standard constants such as V_ASN1_OCTET_STRING.
ASN1_STRING_to_UTF8() converts the string in to
UTF8 format, the converted data is allocated in a buffer in *out.
The length of out is returned or a negative
error code. The buffer *out should be free
using OPENSSL_free().
NOTES
Almost all ASN1 types in OpenSSL are represented as an ASN1_STRING structure.
Other types such as ASN1_OCTET_STRING are simply
typedefed to ASN1_STRING and the functions
call the ASN1_STRING equivalents. ASN1_STRING is
also used for some CHOICE types which consist
entirely of primitive string types such as DirectoryString and Time.
These functions should not be used to
examine or modify ASN1_INTEGER or ASN1_ENUMERATED types: the
relevant INTEGER or ENUMERATED utility
functions should be used instead.
In general it cannot be assumed that the data returned by
ASN1_STRING_data() is null terminated or does not contain embedded
nulls. The actual format of the data will depend on the actual string
type itself: for example for and IA5String the data will be ASCII,
for a BMPString two bytes per character in big endian format, UTF8String
will be in UTF8 format.
Similar care should be take to ensure the data is in the correct
format when calling ASN1_STRING_set().
