ASN1_STRING_length.pod 3.9 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_type, ASN1_STRING_get0_data, ASN1_STRING_data,
  5. ASN1_STRING_to_UTF8 - ASN1_STRING utility functions
  6. =head1 SYNOPSIS
  7. #include <openssl/asn1.h>
  8. int ASN1_STRING_length(ASN1_STRING *x);
  9. const unsigned char * ASN1_STRING_get0_data(const ASN1_STRING *x);
  10. unsigned char * ASN1_STRING_data(ASN1_STRING *x);
  11. ASN1_STRING * ASN1_STRING_dup(ASN1_STRING *a);
  12. int ASN1_STRING_cmp(ASN1_STRING *a, ASN1_STRING *b);
  13. int ASN1_STRING_set(ASN1_STRING *str, const void *data, int len);
  14. int ASN1_STRING_type(const ASN1_STRING *x);
  15. int ASN1_STRING_to_UTF8(unsigned char **out, const ASN1_STRING *in);
  16. =head1 DESCRIPTION
  17. These functions allow an B<ASN1_STRING> structure to be manipulated.
  18. ASN1_STRING_length() returns the length of the content of B<x>.
  19. ASN1_STRING_get0_data() returns an internal pointer to the data of B<x>.
  20. Since this is an internal pointer it should B<not> be freed or
  21. modified in any way.
  22. ASN1_STRING_data() is similar to ASN1_STRING_get0_data() except the
  23. returned value is not constant. This function is deprecated:
  24. applications should use ASN1_STRING_get0_data() instead.
  25. ASN1_STRING_dup() returns a copy of the structure B<a>.
  26. ASN1_STRING_cmp() compares B<a> and B<b> returning 0 if the two
  27. are identical. The string types and content are compared.
  28. ASN1_STRING_set() sets the data of string B<str> to the buffer
  29. B<data> or length B<len>. The supplied data is copied. If B<len>
  30. is -1 then the length is determined by strlen(data).
  31. ASN1_STRING_type() returns the type of B<x>, using standard constants
  32. such as B<V_ASN1_OCTET_STRING>.
  33. ASN1_STRING_to_UTF8() converts the string B<in> to UTF8 format, the
  34. converted data is allocated in a buffer in B<*out>. The length of
  35. B<out> is returned or a negative error code. The buffer B<*out>
  36. should be freed using OPENSSL_free().
  37. =head1 NOTES
  38. Almost all ASN1 types in OpenSSL are represented as an B<ASN1_STRING>
  39. structure. Other types such as B<ASN1_OCTET_STRING> are simply typedef'ed
  40. to B<ASN1_STRING> and the functions call the B<ASN1_STRING> equivalents.
  41. B<ASN1_STRING> is also used for some B<CHOICE> types which consist
  42. entirely of primitive string types such as B<DirectoryString> and
  43. B<Time>.
  44. These functions should B<not> be used to examine or modify B<ASN1_INTEGER>
  45. or B<ASN1_ENUMERATED> types: the relevant B<INTEGER> or B<ENUMERATED>
  46. utility functions should be used instead.
  47. In general it cannot be assumed that the data returned by ASN1_STRING_data()
  48. is null terminated or does not contain embedded nulls. The actual format
  49. of the data will depend on the actual string type itself: for example
  50. for an IA5String the data will be ASCII, for a BMPString two bytes per
  51. character in big endian format, and for an UTF8String it will be in UTF8 format.
  52. Similar care should be take to ensure the data is in the correct format
  53. when calling ASN1_STRING_set().
  54. =head1 RETURN VALUES
  55. ASN1_STRING_length() returns the length of the content of B<x>.
  56. ASN1_STRING_get0_data() and ASN1_STRING_data() return an internal pointer to
  57. the data of B<x>.
  58. ASN1_STRING_dup() returns a valid B<ASN1_STRING> structure or B<NULL> if an
  59. error occurred.
  60. ASN1_STRING_cmp() returns an integer greater than, equal to, or less than 0,
  61. according to whether B<a> is greater than, equal to, or less than B<b>.
  62. ASN1_STRING_set() returns 1 on success or 0 on error.
  63. ASN1_STRING_type() returns the type of B<x>.
  64. ASN1_STRING_to_UTF8() returns the number of bytes in output string B<out> or a
  65. negative value if an error occurred.
  66. =head1 SEE ALSO
  67. L<ERR_get_error(3)>
  68. =head1 COPYRIGHT
  69. Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved.
  70. Licensed under the OpenSSL license (the "License"). You may not use
  71. this file except in compliance with the License. You can obtain a copy
  72. in the file LICENSE in the source distribution or at
  73. L<https://www.openssl.org/source/license.html>.
  74. =cut