[SOLVED] How to provide an initialization vector with XML Encryption Syntax

How to provide an initialization vector with XML Encryption Syntax

I encrypt my data with AES with a key and a random IV. This key I encrypt with RSA and include it in my EncryptedData as seen below. I need to include the IV too but how do I include it with XML Encryption Syntax as the KeyInfo element is already occupied by the EncryptedKey element?

<?xml version='1.0' encoding='UTF-8'?>
<EncryptedData Type="http://www.w3.org/2001/04/xmlenc#Element"
    xmlns="http://www.w3.org/2001/04/xmlenc#">
    <EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#aes256-cbf" />
    <KeyInfo xmlns="http://www.w3.org/2000/09/xmldsig#">
        <EncryptedKey xmlns="http://www.w3.org/2001/04/xmlenc#">
            <EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#rsa-oaep-mgf1p">
                <KeySize>256</KeySize>
                <OAEPparams>AA==</OAEPparams>
                <DigestMethod xmlns="http://www.w3.org/2000/09/xmldsig#"
                    Algorithm="http://www.w3.org/2000/09/xmldsig#sha1" />
            </EncryptionMethod>
            <KeyInfo xmlns="http://www.w3.org/2000/09/xmldsig#">
                <KeyName>client provided public key</KeyName>
            </KeyInfo>
            <CipherData>
                <CipherValue>...</CipherValue>
            </CipherData>
        </EncryptedKey>
    </KeyInfo>
    <CipherData>
        <CipherValue>...</CipherValue>
    </CipherData>
</EncryptedData>

Solution

As per XMLEnc (see 5.2.2) the IV is placed in front of the encrypted data and is not included as a part of the key. Neither XMLEnc specification says anything about including the IV with the key during KeyTransport or KeyWrap procedure.