NAME
ASN1_STRING_print_ex, ASN1_STRING_print_ex_fp, ASN1_STRING_print - ASN1_STRING
output routines.
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
#include <openssl/asn1.h>
int ASN1_STRING_print_ex(BIO *out, ASN1_STRING *str, unsigned long flags);
int ASN1_STRING_print_ex_fp(FILE *fp, ASN1_STRING *str, unsigned long flags);
int ASN1_STRING_print(BIO *out, ASN1_STRING *str);
DESCRIPTION
These functions output an
ASN1_STRING structure.
ASN1_STRING is
used to represent all the ASN1 string types.
ASN1_STRING_print_ex() outputs
str to
out, the format is
determined by the options
flags.
ASN1_STRING_print_ex_fp() is
identical except it outputs to
fp instead.
ASN1_STRING_print() prints
str to
out but using a different
format to
ASN1_STRING_print_ex(). It replaces unprintable characters
(other than CR, LF) with '.'.
NOTES
ASN1_STRING_print() is a legacy function which should be avoided in new
applications.
Although there are a large number of options frequently
ASN1_STRFLGS_RFC2253 is suitable, or on UTF8 terminals
ASN1_STRFLGS_RFC2253 & ~ASN1_STRFLGS_ESC_MSB.
The complete set of supported options for
flags is listed below.
Various characters can be escaped. If
ASN1_STRFLGS_ESC_2253 is set the
characters determined by RFC2253 are escaped. If
ASN1_STRFLGS_ESC_CTRL
is set control characters are escaped. If
ASN1_STRFLGS_ESC_MSB is set
characters with the MSB set are escaped: this option should
not be used
if the terminal correctly interprets UTF8 sequences.
Escaping takes several forms.
If the character being escaped is a 16 bit character then the form
"\UXXXX" is used using exactly four characters for the hex
representation. If it is 32 bits then "\WXXXXXXXX" is used using
eight characters of its hex representation. These forms will only be used if
UTF8 conversion is not set (see below).
Printable characters are normally escaped using the backslash '\' character. If
ASN1_STRFLGS_ESC_QUOTE is set then the whole string is instead
surrounded by double quote characters: this is arguably more readable than the
backslash notation. Other characters use the "\XX" using exactly two
characters of the hex representation.
If
ASN1_STRFLGS_UTF8_CONVERT is set then characters are converted to UTF8
format first. If the terminal supports the display of UTF8 sequences then this
option will correctly display multi byte characters.
If
ASN1_STRFLGS_IGNORE_TYPE is set then the string type is not
interpreted at all: everything is assumed to be one byte per character. This
is primarily for debugging purposes and can result in confusing output in
multi character strings.
If
ASN1_STRFLGS_SHOW_TYPE is set then the string type itself is printed
out before its value (for example "BMPSTRING"), this actually uses
ASN1_tag2str().
The content of a string instead of being interpreted can be "dumped":
this just outputs the value of the string using the form #XXXX using hex
format for each octet.
If
ASN1_STRFLGS_DUMP_ALL is set then any type is dumped.
Normally non character string types (such as OCTET STRING) are assumed to be one
byte per character, if
ASN1_STRFLGS_DUMP_UNKNOWN is set then they will
be dumped instead.
When a type is dumped normally just the content octets are printed, if
ASN1_STRFLGS_DUMP_DER is set then the complete encoding is dumped
instead (including tag and length octets).
ASN1_STRFLGS_RFC2253 includes all the flags required by RFC2253. It is
equivalent to:
ASN1_STRFLGS_ESC_2253 | ASN1_STRFLGS_ESC_CTRL | ASN1_STRFLGS_ESC_MSB |
ASN1_STRFLGS_UTF8_CONVERT | ASN1_STRFLGS_DUMP_UNKNOWN ASN1_STRFLGS_DUMP_DER
SEE ALSO
X509_NAME_print_ex(3),
ASN1_tag2str(3)
HISTORY
TBA