Home | History | Annotate | Line # | Download | only in man3 
      1 =pod
      2 
      3 =head1 NAME
      4 
      5 ASN1_STRING_dup, ASN1_STRING_cmp, ASN1_STRING_set, ASN1_STRING_length,
      6 ASN1_STRING_type, ASN1_STRING_get0_data, ASN1_STRING_data,
      7 ASN1_STRING_to_UTF8 - ASN1_STRING utility functions
      8 
      9 =head1 SYNOPSIS
     10 
     11  #include <openssl/asn1.h>
     12 
     13  int ASN1_STRING_length(ASN1_STRING *x);
     14  const unsigned char *ASN1_STRING_get0_data(const ASN1_STRING *x);
     15  unsigned char *ASN1_STRING_data(ASN1_STRING *x);
     16 
     17  ASN1_STRING *ASN1_STRING_dup(const ASN1_STRING *a);
     18 
     19  int ASN1_STRING_cmp(ASN1_STRING *a, ASN1_STRING *b);
     20 
     21  int ASN1_STRING_set(ASN1_STRING *str, const void *data, int len);
     22 
     23  int ASN1_STRING_type(const ASN1_STRING *x);
     24 
     25  int ASN1_STRING_to_UTF8(unsigned char **out, const ASN1_STRING *in);
     26 
     27 =head1 DESCRIPTION
     28 
     29 These functions allow an B<ASN1_STRING> structure to be manipulated.
     30 
     31 ASN1_STRING_length() returns the length of the content of I<x>. I<x> B<MUST NOT> be NULL.
     32 
     33 ASN1_STRING_get0_data() returns an internal pointer to the data of I<x>.
     34 Since this is an internal pointer it should B<not> be freed or
     35 modified in any way. I<x> B<MUST NOT> be NULL.
     36 
     37 ASN1_STRING_data() is similar to ASN1_STRING_get0_data() except the
     38 returned value is not constant. This function is deprecated:
     39 applications should use ASN1_STRING_get0_data() instead.
     40 
     41 ASN1_STRING_dup() returns a copy of the structure I<a>.
     42 
     43 ASN1_STRING_cmp() compares I<a> and I<b> returning 0 if the two
     44 are identical. The string types and content are compared.
     45 
     46 ASN1_STRING_set() sets the data of string I<str> to the buffer
     47 I<data> or length I<len>. The supplied data is copied. If I<len>
     48 is -1 then the length is determined by strlen(data).
     49 
     50 ASN1_STRING_type() returns the type of I<x>, using standard constants
     51 such as B<V_ASN1_OCTET_STRING>.
     52 
     53 ASN1_STRING_to_UTF8() converts the string I<in> to UTF8 format, the
     54 converted data is allocated in a buffer in I<*out>. The length of
     55 I<out> is returned or a negative error code. The buffer I<*out>
     56 should be freed using OPENSSL_free().
     57 
     58 =head1 NOTES
     59 
     60 Almost all ASN1 types in OpenSSL are represented as an B<ASN1_STRING>
     61 structure. Other types such as B<ASN1_OCTET_STRING> are simply typedef'ed
     62 to B<ASN1_STRING> and the functions call the B<ASN1_STRING> equivalents.
     63 B<ASN1_STRING> is also used for some B<CHOICE> types which consist
     64 entirely of primitive string types such as B<DirectoryString> and
     65 B<Time>.
     66 
     67 These functions should B<not> be used to examine or modify B<ASN1_INTEGER>
     68 or B<ASN1_ENUMERATED> types: the relevant B<INTEGER> or B<ENUMERATED>
     69 utility functions should be used instead.
     70 
     71 In general it cannot be assumed that the data returned by ASN1_STRING_data()
     72 is null terminated or does not contain embedded nulls. The actual format
     73 of the data will depend on the actual string type itself: for example
     74 for an IA5String the data will be ASCII, for a BMPString two bytes per
     75 character in big endian format, and for a UTF8String it will be in UTF8 format.
     76 
     77 Similar care should be take to ensure the data is in the correct format
     78 when calling ASN1_STRING_set().
     79 
     80 =head1 RETURN VALUES
     81 
     82 ASN1_STRING_length() returns the length of the content of I<x>.
     83 
     84 ASN1_STRING_get0_data() and ASN1_STRING_data() return an internal pointer to
     85 the data of I<x>.
     86 
     87 ASN1_STRING_dup() returns a valid B<ASN1_STRING> structure or NULL if an
     88 error occurred.
     89 
     90 ASN1_STRING_cmp() returns an integer greater than, equal to, or less than 0,
     91 according to whether I<a> is greater than, equal to, or less than I<b>.
     92 
     93 ASN1_STRING_set() returns 1 on success or 0 on error.
     94 
     95 ASN1_STRING_type() returns the type of I<x>.
     96 
     97 ASN1_STRING_to_UTF8() returns the number of bytes in output string I<out> or a
     98 negative value if an error occurred.
     99 
    100 =head1 SEE ALSO
    101 
    102 L<ERR_get_error(3)>
    103 
    104 =head1 COPYRIGHT
    105 
    106 Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved.
    107 
    108 Licensed under the Apache License 2.0 (the "License").  You may not use
    109 this file except in compliance with the License.  You can obtain a copy
    110 in the file LICENSE in the source distribution or at
    111 L<https://www.openssl.org/source/license.html>.
    112 
    113 =cut
    114