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<head><title>dkim_sig_getcanonlen()</title></head>
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<h1>dkim_sig_getcanonlen()</h1>
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<!---------- Synopsis ----------->
<tr><th valign="top" align=left width=150>SYNOPSIS</th><td>
<pre>
#include <dkim.h>
<a href="dkim_stat.html"><tt>DKIM_STAT</tt></a> dkim_sig_getcanonlen(
<a href="dkim.html"><tt>DKIM</tt></a> *dkim,
<a href="dkim_siginfo.html"><tt>DKIM_SIGINFO</tt></a> *sig,
ssize_t *msglen,
ssize_t *canonlen,
ssize_t *signlen
);
</pre>
Retrieve the number of bytes of message body presented for signing
or verifying, and/or the number of bytes actually signed or verified.
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<!----------- Description ---------->
<tr><th valign="top" align=left>DESCRIPTION</th><td>
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<th width="80">Called When</th>
<td><tt>dkim_sig_getcanonlen()</tt> is called after
<a href="dkim_eom.html"><tt>dkim_eom()</tt></a> to get the number of
bytes of message body presented for signing or verifying, and/or
the number of bytes actually signed or verified. This is used to
allow a verifier to insist on minimum signing volumes or
percentages (e.g., a verifier may decide not to trust a message which
was only partially signed). </td>
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<!----------- Arguments ---------->
<tr><th valign="top" align=left>ARGUMENTS</th><td>
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<tr bgcolor="#dddddd"><th>Argument</th><th>Description</th></tr>
<tr valign="top"><td>dkim</td>
<td>Message-specific handle, returned by
<a href="dkim_sign.html"><tt>dkim_sign()</tt></a> or
<a href="dkim_verify.html"><tt>dkim_verify</tt></a>.
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<tr valign="top"><td>sig</td>
<td>The <tt>DKIM_SIGINFO</tt> handle representing the signature
being evaluated.
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<tr valign="top"><td>msglen</td>
<td>A pointer to an <tt>ssize_t</tt> which will receive a count of
the number of bytes in the <i>canonicalized</i> form of the message.
This should always be the number of bytes in the message body
plus or minus whatever was required to canonicalize it (so for
"simple" canonicalization it should be roughly the exact byte count,
while for "relaxed" canonicalization it should be somewhat less).
Can be NULL if this information is not needed by the caller.
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<tr valign="top"><td>canonlen</td>
<td>A pointer to an <tt>ssize_t</tt> which will receive a count of
the number of bytes in the <i>canonicalized</i> form of the message
that were included in the signed data. If <tt>msglen</tt> and
<tt>canonlen</tt> are the same, then the entire message was signed.
If it is less, then the signer didn't sign the entire message.
A verifier can compare this value with that of <tt>msglen</tt>
to see what portion of the total message was signed by the signer.
Note that <tt>msglen</tt> and <tt>canonlen</tt> can differ even if
no signature length limit was set if, for example, there were
trailing blank lines on the message as these are always stripped.
Can be NULL if this information is not needed by the caller.
</td></tr>
<tr valign="top"><td>signlen</td>
<td>A pointer to an <tt>ssize_t</tt> which will receive the signature
length limit for this signature (i.e. the value of the "l=" tag
if one was present on the signature). If no limit was set by
the signer, a value of -1 is returned.
Can be NULL if this information is not needed by the caller.
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<!----------- Notes ---------->
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<th valign="top" align=left>NOTES</th>
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<li>None.
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Copyright (c) 2005-2007 Sendmail, Inc. and its suppliers.
All rights reserved.
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Copyright (c) 2009-2011, The OpenDKIM Project. All rights reserved.
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By using this file, you agree to the terms and conditions set
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