| SYNOPSIS | 
#include <dkim.h>
DKIM_STAT dkim_getsighdr_d(
	DKIM *dkim,
        size_t initial,
        unsigned char **buf,
        size_t *len
);
Compute and retrieve the signature header for a message.  This is similar
to dkim_getsighdr() except that
memory will be allocated for an arbitrarily long signature header, and
a pointer to that memory will be returned as well as the length of the string
at that location.
The memory thus allocated will be deallocated by the library when the
dkim handle is closed.  
 | 
|---|
| DESCRIPTION | 
| Called When | dkim_getsig() is called after
    dkim_eom() when dkim is a
    signing handle, i.e. one returned by an earlier call to
    dkim_sign(). |  | 
|---|
| ARGUMENTS | 
    | Argument | Description | 
|---|
 | dkim | Message-specific handle, returned by 
        dkim_sign(). |  | initial | Line length already consumed on the first line.  Used to
            leave space when wrapping headers for the name of the header
            itself. |  | buf | The address of a pointer that will be updated to reference
	    a buffer into which the generated signature header was
	    placed.  The buffer is NUL-terminated. |  | len | The address of an integer that will be updated to contain the
	    length of the generated signature header.  The length does not
	    include the NUL byte at the end. |  | 
|---|
| NOTES | 
It is an error to call this function with a handle that was created
    using dkim_verify().
If for example, you want to have your headers wrapped at 75 bytes
    and the header to be added will be called "DKIM-Signature", the
    initial value should be 16 (length of the header's name plus
    room for a colon and a space).  The default margin is 75; see
    dkim_set_margin().
When signing and "simple" canonicalization is in use, the header added to
    the message must be identical to the internal version used to generate the
    signature, or the message will not verify.  In that case, the value of
    initial should be 16 (or more portably,
    strlen(DKIM_SIGNHEADER) + 2). 
 |