ASN1_STRING_length.pod 2.7 KB

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  1. =pod
  2. =head1 NAME
  3. ASN1_STRING_dup, ASN1_STRING_cmp, ASN1_STRING_set, ASN1_STRING_length,
  4. ASN1_STRING_length_set, ASN1_STRING_type, ASN1_STRING_data, ASN1_STRING_to_UTF8 -
  5. ASN1_STRING utility functions
  6. =head1 SYNOPSIS
  7. #include <openssl/asn1.h>
  8. int ASN1_STRING_length(ASN1_STRING *x);
  9. unsigned char * ASN1_STRING_data(ASN1_STRING *x);
  10. ASN1_STRING * ASN1_STRING_dup(ASN1_STRING *a);
  11. int ASN1_STRING_cmp(ASN1_STRING *a, ASN1_STRING *b);
  12. int ASN1_STRING_set(ASN1_STRING *str, const void *data, int len);
  13. int ASN1_STRING_type(ASN1_STRING *x);
  14. int ASN1_STRING_to_UTF8(unsigned char **out, ASN1_STRING *in);
  15. =head1 DESCRIPTION
  16. These functions allow an B<ASN1_STRING> structure to be manipulated.
  17. ASN1_STRING_length() returns the length of the content of B<x>.
  18. ASN1_STRING_data() returns an internal pointer to the data of B<x>.
  19. Since this is an internal pointer it should B<not> be freed or
  20. modified in any way.
  21. ASN1_STRING_dup() returns a copy of the structure B<a>.
  22. ASN1_STRING_cmp() compares B<a> and B<b> returning 0 if the two
  23. are identical. The string types and content are compared.
  24. ASN1_STRING_set() sets the data of string B<str> to the buffer
  25. B<data> or length B<len>. The supplied data is copied. If B<len>
  26. is -1 then the length is determined by strlen(data).
  27. ASN1_STRING_type() returns the type of B<x>, using standard constants
  28. such as B<V_ASN1_OCTET_STRING>.
  29. ASN1_STRING_to_UTF8() converts the string B<in> to UTF8 format, the
  30. converted data is allocated in a buffer in B<*out>. The length of
  31. B<out> is returned or a negative error code. The buffer B<*out>
  32. should be free using OPENSSL_free().
  33. =head1 NOTES
  34. Almost all ASN1 types in OpenSSL are represented as an B<ASN1_STRING>
  35. structure. Other types such as B<ASN1_OCTET_STRING> are simply typedefed
  36. to B<ASN1_STRING> and the functions call the B<ASN1_STRING> equivalents.
  37. B<ASN1_STRING> is also used for some B<CHOICE> types which consist
  38. entirely of primitive string types such as B<DirectoryString> and
  39. B<Time>.
  40. These functions should B<not> be used to examine or modify B<ASN1_INTEGER>
  41. or B<ASN1_ENUMERATED> types: the relevant B<INTEGER> or B<ENUMERATED>
  42. utility functions should be used instead.
  43. In general it cannot be assumed that the data returned by ASN1_STRING_data()
  44. is null terminated or does not contain embedded nulls. The actual format
  45. of the data will depend on the actual string type itself: for example
  46. for and IA5String the data will be ASCII, for a BMPString two bytes per
  47. character in big endian format, UTF8String will be in UTF8 format.
  48. Similar care should be take to ensure the data is in the correct format
  49. when calling ASN1_STRING_set().
  50. =head1 RETURN VALUES
  51. =head1 SEE ALSO
  52. L<ERR_get_error(3)|ERR_get_error(3)>
  53. =head1 HISTORY
  54. =cut