Function : Basic Encoding Rules

ber_printf - Used to encode a BerElement

#include <lber.h>
int LNVARARGS ber_printf(

    BerElement *ber,
    const char *fmt,
    <Any 'C' type>  optional_var1, ...);

Description :

This routine is used to encode a BerElement in much the same way that sprintf() works. One important difference, though, is that state information is kept in the ber argument so that multiple calls can be made to ber_printf() to append to the end of the BER element. Ber_printf() writes to ber, a pointer to a BerElement. It interprets and formats its arguments according to the format string fmt. As with sprintf(), each character in fmt refers to an argument to ber_printf().The format string can contain the following characters:

't' Tag.
The next argument is a ber_tag_t specifying the tag to override the next element to be written to the ber. This works across calls. The integer tag value should contain the tag class, constructed bit, and tag value. For example, a tag of "[3]" for a constructed type is 0xA3U. All implementations MUST support tags that fit in a single octet (i.e., where the tag value is less than 32) and they MAY support larger tags.

'b' Boolean.
The next argument is an ber_int_t, containing either 0 for FALSE or 0xff for TRUE. A boolean element is output. If this format character is not preceded by the 't' format modifier, the tag 0x01U is used for the element.

'e' Enumerated.
The next argument is a ber_int_t, containing the enumerated value in the host's byte order. An enumerated element is output. If this format character is not preceded by the 't' format modifier, the tag 0x0AU is used for the element.

'i' Integer.
The next argument is a ber_int_t, containing the integer in the host's byte order. An integer element is output. If this format character is not preceded by the 't' format modifier, the tag 0x02U is used for the element.

'B' Bitstring.
The next two arguments are a char * pointer to the start of the bitstring, followed by a ber_len_t containing the number of bits in the bitstring. A bitstring element is output, in primitive form. If this format character is not preceded by the 't' format modifier, the tag 0x03U is used for the element.

'X' Reserved and not to be used.

'n' Null.
No argument is needed. An ASN.1 NULL element is output. If this format character is not preceded by the 't' format modifier, the tag 0x05U is used for the element.

'o' Octet string.
The next two arguments are a char *, followed by a ber_len_t with the length of the string. The string may contain null bytes and are do not have to be zero-terminated. An octet string element is output, in primitive form. If this format character is not preceded by the 't' format modifier, the tag 0x04U is used for the element.

's' Octet string.
The next argument is a char * pointing to a zero-terminated string. An octet string element in primitive form is output, which does not include the trailing '\0' (null) byte. If this format character is not preceded by the 't' format modifier, the tag 0x04U is used for the element.

'v' Several octet strings.
The next argument is a char **, an array of char * pointers to zero-terminated strings. The last element in the array must be a NULL pointer. The octet strings do not include the trailing '\0' (null) byte. Note that a construct like '{v}' is used to get an actual sequence of octet strings. The 't' format modifier cannot be used with this format character.

'V' Several octet strings.
A NULL-terminated array of struct berval *'s is supplied. Note that a construct like '{V}' is used to get an actual sequence of octet strings. The 't' format modifier cannot be used with this format character.

'{' Begin sequence.
No argument is needed. If this format character is not preceded by the 't' format modifier, the tag 0x30U is used.

'}' End sequence.
No argument is needed. The 't' format modifier cannot be used with this format character.

'[' Begin set.
No argument is needed. If this format character is not preceded by the 't' format modifier, the tag 0x31U is used.

']' End set.
No argument is needed. The 't' format modifier cannot be used with this format character.

Each use of a '{' format character should be matched by a '}' character, either later in the format string, or in the format string of a subsequent call to ber_printf() for that BerElement. The same applies to the '[' and ']' format characters.

Sequences and sets nest, and implementations of this API must maintain internal state to be able to properly calculate the lengths.

Implemented as a macro:

define ber_printf ND_ber_printf

Parameters : Input : ber - Must be a pointer to a BerElement returned by ber_alloc_t().

fmt - Routine interprets and formats its arguments according to this format string.

optional_var1, ... - Optional argument.

Output : (routine) - -1 if there is an error during encoding and a non-negative number if successful.