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