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ASN1_PUT_OBJECT(3)     FreeBSD Library Functions Manual	    ASN1_PUT_OBJECT(3)

NAME
     ASN1_put_object, ASN1_put_eoc -- start and	end the	BER encoding of	an ar-
     bitrary ASN.1 data	element

SYNOPSIS
     #include <openssl/asn1.h>

     void
     ASN1_put_object(unsigned char **ber_out, int constructed, int length,
	 int tag, int class);

     int
     ASN1_put_eoc(unsigned char	**ber_out);

DESCRIPTION
     ASN1_put_object() begins writing the BER encoding of an arbitrary ASN.1
     data element to the buffer	*ber_out by writing the	identifier and the
     length bytes.  Making sure	that there is sufficient space in the buffer
     is	the responsibility of the caller.  This	function does not write	any
     content bytes nor any end-of-content bytes.

     The tag class can be V_ASN1_UNIVERSAL, V_ASN1_APPLICATION,
     V_ASN1_CONTEXT_SPECIFIC, or V_ASN1_PRIVATE	and is written to the two most
     significant bits of the first byte	written.

     The constructed argument can have the following values:
       0  Start	a primitive value by setting the third most significant	bit of
	  the first byte written to 0.	Always use the definite	form.
       1  Start	a constructed value by setting the third most significant bit
	  of the first byte written to 1, and use the definite form.
       2  Start	a constructed value and	use the	indefinite form,

     If	the tag	is less	than 0x1f, it is written to the	five least significant
     bits of the only identifier byte written.	Otherwise, these five bits are
     all set to	1, and the tag is encoded in one or more following identifier
     bytes as needed.

     After completing the identifier byte(s), when using the definite form,
     the given length is encoded in one	or more	bytes as needed.  Otherwise,
     the special byte 0x80 is written instead and the length argument is ig-
     nored.

     At	the end, *ber_out is set to the	byte following the last	byte written.
     The calling code can then start writing content bytes.

     If	the indefinite form was	selected, the calling code is also responsible
     for calling ASN1_put_eoc()	which writes an	end-of-content marker to
     *ber_out, consisting of two NUL bytes, and	advances *ber_out by two
     bytes.

RETURN VALUES
     ASN1_put_eoc() returns the	number of bytes	written, which is always 2.

SEE ALSO
     ASN1_item_i2d(3), ASN1_TYPE_get(3), i2d_ASN1_NULL(3), i2d_ASN1_OBJECT(3),
     i2d_ASN1_OCTET_STRING(3), i2d_ASN1_SEQUENCE_ANY(3)

HISTORY
     ASN1_put_object() first appeared in SSLeay	0.5.1 and has been available
     since OpenBSD 2.4.

     ASN1_put_eoc() first appeared in OpenSSL 0.9.8 and	has been available
     since OpenBSD 4.5.

CAVEATS
     Neither ASN1_put_object() nor ASN1_put_eoc() do any sanity	checking.
     When called in inconsistent ways, invalid content may result in *ber_out,
     for example
     -	 a tag number less than	0x1f with a non-universal class
     -	 a tag number equal to 0x00 or 0x1f
     -	 a BOOLEAN, INTEGER, NULL etc. with the	constructed bit	set
     -	 a SEQUENCE or SET etc.	without	the constructed	bit set
     -	 a length that makes no	sense for the given tag
     -	 a length that disagrees with the following data
     -	 a BOOLEAN, INTEGER, NULL etc. in indefinite form
     -	 an end-of-content marker even though no indefinite form was started
     -	 ...

     If	the calling code wants to find out how many bytes were written,	it
     needs to save a copy of the pointer *ber_out before calling
     ASN1_put_object().

FreeBSD	13.0			August 26, 2019			  FreeBSD 13.0

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | HISTORY | CAVEATS

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