#include <openssl/x509.h> int X509_NAME_print_ex(BIO *out, X509_NAME *nm, int indent, unsigned long flags); int X509_NAME_print_ex_fp(FILE *fp, X509_NAME *nm, int indent, unsigned long flags); char * X509_NAME_oneline(X509_NAME *a,char *buf,int size); int X509_NAME_print(BIO *bp, X509_NAME *name, int obase);
X509_NAME_print_ex_fp() is identical to X509_NAME_print_ex() except the output is written to FILE pointer fp.
X509_NAME_oneline() prints an ASCII version of a to buf. At most size bytes will be written. If buf is NULL then a buffer is dynamically allocated and returned, otherwise buf is returned.
X509_NAME_print() prints out name to bp indenting each line by obase characters. Multiple lines are used if the output (including indent) exceeds 80 characters.
Although there are a large number of possible flags for most purposes XN_FLAG_ONELINE, XN_FLAG_MULTILINE or XN_FLAG_RFC2253 will suffice. As noted on the ASN1_STRING_print_ex(3) manual page for UTF8 terminals the ASN1_STRFLGS_ESC_MSB should be unset: so for example XN_FLAG_ONELINE & ~ASN1_STRFLGS_ESC_MSB would be used.
The complete set of the flags supported by X509_NAME_print_ex() is listed below.
Several options can be ored together.
The options XN_FLAG_SEP_COMMA_PLUS, XN_FLAG_SEP_CPLUS_SPC, XN_FLAG_SEP_SPLUS_SPC and XN_FLAG_SEP_MULTILINE determine the field separators to use. Two distinct separators are used between distinct RelativeDistinguishedName components and separate values in the same RDN for a multi-valued RDN. Multi-valued RDNs are currently very rare so the second separator will hardly ever be used.
XN_FLAG_SEP_COMMA_PLUS uses comma and plus as separators. XN_FLAG_SEP_CPLUS_SPC uses comma and plus with spaces: this is more readable that plain comma and plus. XN_FLAG_SEP_SPLUS_SPC uses spaced semicolon and plus. XN_FLAG_SEP_MULTILINE uses spaced newline and plus respectively.
If XN_FLAG_DN_REV is set the whole DN is printed in reversed order.
The fields XN_FLAG_FN_SN, XN_FLAG_FN_LN, XN_FLAG_FN_OID, XN_FLAG_FN_NONE determine how a field name is displayed. It will use the short name (e.g. CN) the long name (e.g. commonName) always use OID numerical form (normally OIDs are only used if the field name is not recognised) and no field name respectively.
If XN_FLAG_SPC_EQ is set then spaces will be placed around the '=' character separating field names and values.
If XN_FLAG_DUMP_UNKNOWN_FIELDS is set then the encoding of unknown fields is printed instead of the values.
If XN_FLAG_FN_ALIGN is set then field names are padded to 20 characters: this is only of use for multiline format.
Additionally all the options supported by ASN1_STRING_print_ex() can be used to control how each field value is displayed.
In addition a number options can be set for commonly used formats.
XN_FLAG_RFC2253 sets options which produce an output compatible with RFC2253 it
is equivalent to:
ASN1_STRFLGS_RFC2253 | XN_FLAG_SEP_COMMA_PLUS | XN_FLAG_DN_REV | XN_FLAG_FN_SN | XN_FLAG_DUMP_UNKNOWN_FIELDS
XN_FLAG_ONELINE is a more readable one line format which is the same as:
ASN1_STRFLGS_RFC2253 | ASN1_STRFLGS_ESC_QUOTE | XN_FLAG_SEP_CPLUS_SPC | XN_FLAG_SPC_EQ | XN_FLAG_FN_SN
XN_FLAG_MULTILINE is a multiline format which is the same as:
ASN1_STRFLGS_ESC_CTRL | ASN1_STRFLGS_ESC_MSB | XN_FLAG_SEP_MULTILINE | XN_FLAG_SPC_EQ | XN_FLAG_FN_LN | XN_FLAG_FN_ALIGN
XN_FLAG_COMPAT uses a format identical to X509_NAME_print(): in fact it calls X509_NAME_print() internally.