1=pod 2 3=head1 NAME 4 5ASN1_tag2str, ASN1_STRING_print_ex, ASN1_STRING_print_ex_fp, ASN1_STRING_print 6- ASN1_STRING output routines 7 8=head1 SYNOPSIS 9 10 #include <openssl/asn1.h> 11 12 int ASN1_STRING_print_ex(BIO *out, const ASN1_STRING *str, unsigned long flags); 13 int ASN1_STRING_print_ex_fp(FILE *fp, const ASN1_STRING *str, unsigned long flags); 14 int ASN1_STRING_print(BIO *out, const ASN1_STRING *str); 15 16 const char *ASN1_tag2str(int tag); 17 18=head1 DESCRIPTION 19 20These functions output an B<ASN1_STRING> structure. B<ASN1_STRING> is used to 21represent all the ASN1 string types. 22 23ASN1_STRING_print_ex() outputs B<str> to B<out>, the format is determined by 24the options B<flags>. ASN1_STRING_print_ex_fp() is identical except it outputs 25to B<fp> instead. 26 27ASN1_STRING_print() prints B<str> to B<out> but using a different format to 28ASN1_STRING_print_ex(). It replaces unprintable characters (other than CR, LF) 29with '.'. 30 31ASN1_tag2str() returns a human-readable name of the specified ASN.1 B<tag>. 32 33=head1 NOTES 34 35ASN1_STRING_print() is a deprecated function which should be avoided; use 36ASN1_STRING_print_ex() instead. 37 38Although there are a large number of options frequently B<ASN1_STRFLGS_RFC2253> is 39suitable, or on UTF8 terminals B<ASN1_STRFLGS_RFC2253 & ~ASN1_STRFLGS_ESC_MSB>. 40 41The complete set of supported options for B<flags> is listed below. 42 43Various characters can be escaped. If B<ASN1_STRFLGS_ESC_2253> is set the characters 44determined by RFC2253 are escaped. If B<ASN1_STRFLGS_ESC_CTRL> is set control 45characters are escaped. If B<ASN1_STRFLGS_ESC_MSB> is set characters with the 46MSB set are escaped: this option should B<not> be used if the terminal correctly 47interprets UTF8 sequences. 48 49Escaping takes several forms. 50 51If the character being escaped is a 16 bit character then the form "\UXXXX" is used 52using exactly four characters for the hex representation. If it is 32 bits then 53"\WXXXXXXXX" is used using eight characters of its hex representation. These forms 54will only be used if UTF8 conversion is not set (see below). 55 56Printable characters are normally escaped using the backslash '\' character. If 57B<ASN1_STRFLGS_ESC_QUOTE> is set then the whole string is instead surrounded by 58double quote characters: this is arguably more readable than the backslash 59notation. Other characters use the "\XX" using exactly two characters of the hex 60representation. 61 62If B<ASN1_STRFLGS_UTF8_CONVERT> is set then characters are converted to UTF8 63format first. If the terminal supports the display of UTF8 sequences then this 64option will correctly display multi byte characters. 65 66If B<ASN1_STRFLGS_IGNORE_TYPE> is set then the string type is not interpreted at 67all: everything is assumed to be one byte per character. This is primarily for 68debugging purposes and can result in confusing output in multi character strings. 69 70If B<ASN1_STRFLGS_SHOW_TYPE> is set then the string type itself is printed out 71before its value (for example "BMPSTRING"), this actually uses ASN1_tag2str(). 72 73The content of a string instead of being interpreted can be "dumped": this just 74outputs the value of the string using the form #XXXX using hex format for each 75octet. 76 77If B<ASN1_STRFLGS_DUMP_ALL> is set then any type is dumped. 78 79Normally non character string types (such as OCTET STRING) are assumed to be 80one byte per character, if B<ASN1_STRFLGS_DUMP_UNKNOWN> is set then they will 81be dumped instead. 82 83When a type is dumped normally just the content octets are printed, if 84B<ASN1_STRFLGS_DUMP_DER> is set then the complete encoding is dumped 85instead (including tag and length octets). 86 87B<ASN1_STRFLGS_RFC2253> includes all the flags required by RFC2253. It is 88equivalent to: 89 ASN1_STRFLGS_ESC_2253 | ASN1_STRFLGS_ESC_CTRL | ASN1_STRFLGS_ESC_MSB | 90 ASN1_STRFLGS_UTF8_CONVERT | ASN1_STRFLGS_DUMP_UNKNOWN ASN1_STRFLGS_DUMP_DER 91 92=head1 RETURN VALUES 93 94ASN1_STRING_print_ex() and ASN1_STRING_print_ex_fp() return the number of 95characters written or -1 if an error occurred. 96 97ASN1_STRING_print() returns 1 on success or 0 on error. 98 99ASN1_tag2str() returns a human-readable name of the specified ASN.1 B<tag>. 100 101=head1 SEE ALSO 102 103L<X509_NAME_print_ex(3)>, 104L<ASN1_tag2str(3)> 105 106=head1 COPYRIGHT 107 108Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved. 109 110Licensed under the OpenSSL license (the "License"). You may not use 111this file except in compliance with the License. You can obtain a copy 112in the file LICENSE in the source distribution or at 113L<https://www.openssl.org/source/license.html>. 114 115=cut 116