/** 
 * XML Security Library (http://www.aleksey.com/xmlsec).
 *
 * Memory buffer transform
 *
 * This is free software; see Copyright file in the source
 * distribution for preciese wording.
 * 
 * Copyright (C) 2002-2003 Aleksey Sanin <aleksey@aleksey.com>
 * Portion Copyright © 2009 Nokia Corporation and/or its subsidiary(-ies). All rights reserved. 
 */
#include "xmlsec_globals.h"

#include <stdlib.h>
#include <string.h>
 
#include <libxml2_tree.h>

#include "xmlsec_xmlsec.h"
#include "xmlsec_buffer.h"
#include "xmlsec_keys.h"
#include "xmlsec_transforms.h"
#include "xmlsec_keys.h"
#include "xmlsec_base64.h"
#include "xmlsec_membuf.h"
#include "xmlsec_errors.h"

/*****************************************************************************
 *
 * Memory Buffer Transform
 * 
 * xmlSecBuffer is located after xmlSecTransform
 * 
 ****************************************************************************/
#define xmlSecTransformMemBufSize \
	(sizeof(xmlSecTransform) + sizeof(xmlSecBuffer))
#define xmlSecTransformMemBufGetBuf(transform) \
    ((xmlSecTransformCheckSize((transform), xmlSecTransformMemBufSize)) ? \
	(xmlSecBufferPtr)(((xmlSecByte*)(transform)) + sizeof(xmlSecTransform)) : \
	(xmlSecBufferPtr)NULL)

static int		xmlSecTransformMemBufInitialize		(xmlSecTransformPtr transform);
static void		xmlSecTransformMemBufFinalize		(xmlSecTransformPtr transform);
static int  		xmlSecTransformMemBufExecute		(xmlSecTransformPtr transform, 
								 int last,
								 xmlSecTransformCtxPtr transformCtx);
static xmlSecTransformKlass xmlSecTransformMemBufKlass = {
    /* klass/object sizes */
    sizeof(xmlSecTransformKlass),		/* xmlSecSize klassSize */
    xmlSecTransformMemBufSize,			/* xmlSecSize objSize */

    xmlSecNameMemBuf,				/* const xmlChar* name; */
    NULL,					/* const xmlChar* href; */
    0,						/* xmlSecAlgorithmUsage usage; */

    xmlSecTransformMemBufInitialize, 		/* xmlSecTransformInitializeMethod initialize; */
    xmlSecTransformMemBufFinalize,		/* xmlSecTransformFianlizeMethod finalize; */
    NULL,					/* xmlSecTransformNodeReadMethod readNode; */
    NULL,					/* xmlSecTransformNodeWriteMethod writeNode; */
    NULL,					/* xmlSecTransformSetKeyReqMethod setKeyReq; */
    NULL,					/* xmlSecTransformSetKeyMethod setKey; */
    NULL,					/* xmlSecTransformValidateMethod validate; */
    xmlSecTransformDefaultGetDataType,		/* xmlSecTransformGetDataTypeMethod getDataType; */
    xmlSecTransformDefaultPushBin,		/* xmlSecTransformPushBinMethod pushBin; */
    xmlSecTransformDefaultPopBin,		/* xmlSecTransformPopBinMethod popBin; */
    NULL,					/* xmlSecTransformPushXmlMethod pushXml; */
    NULL,					/* xmlSecTransformPopXmlMethod popXml; */
    xmlSecTransformMemBufExecute,		/* xmlSecTransformExecuteMethod execute; */

    NULL,					/* void* reserved0; */
    NULL,					/* void* reserved1; */
};

/**
 * xmlSecTransformMemBufGetKlass:
 * 
 * The memory buffer transorm (used to store the data that go through it).
 *
 * Returns memory buffer transform klass.
 */
EXPORT_C
xmlSecTransformId 
xmlSecTransformMemBufGetKlass(void) {
    return(&xmlSecTransformMemBufKlass);
}

/**
 * xmlSecTransformMemBufGetBuffer:
 * @transform: 		the pointer to memory buffer transform.
 * 
 * Gets the pointer to memory buffer transform buffer. 
 *
 * Returns pointer to the transform's #xmlSecBuffer. 
 */
EXPORT_C
xmlSecBufferPtr
xmlSecTransformMemBufGetBuffer(xmlSecTransformPtr transform) {
    xmlSecBufferPtr buffer;

    xmlSecAssert2(xmlSecTransformCheckId(transform, xmlSecTransformMemBufId), NULL);
    
    buffer = xmlSecTransformMemBufGetBuf(transform);
    xmlSecAssert2(buffer != NULL, NULL);
    
    return(buffer);
}

static int
xmlSecTransformMemBufInitialize(xmlSecTransformPtr transform) {
    xmlSecBufferPtr buffer;
    int ret;
    
    xmlSecAssert2(xmlSecTransformCheckId(transform, xmlSecTransformMemBufId), -1);

    buffer = xmlSecTransformMemBufGetBuf(transform);
    xmlSecAssert2(buffer != NULL, -1);

    ret = xmlSecBufferInitialize(buffer, 0);
    if(ret < 0) {
	xmlSecError(XMLSEC_ERRORS_HERE,
		    xmlSecErrorsSafeString(xmlSecTransformGetName(transform)),
		    "xmlSecBufferInitialize",
		    XMLSEC_ERRORS_R_XMLSEC_FAILED,
		    XMLSEC_ERRORS_NO_MESSAGE);
	return(-1);
    }
    return(0);    
}

static void
xmlSecTransformMemBufFinalize(xmlSecTransformPtr transform) {
    xmlSecBufferPtr buffer;

    xmlSecAssert(xmlSecTransformCheckId(transform, xmlSecTransformMemBufId));

    buffer = xmlSecTransformMemBufGetBuf(transform);
    xmlSecAssert(buffer != NULL);
    
    xmlSecBufferFinalize(xmlSecTransformMemBufGetBuf(transform)); 
}

static int 
xmlSecTransformMemBufExecute(xmlSecTransformPtr transform, int last, xmlSecTransformCtxPtr transformCtx) {
    xmlSecBufferPtr buffer;
    xmlSecBufferPtr in, out;
    xmlSecSize inSize;
    int ret;

    xmlSecAssert2(xmlSecTransformCheckId(transform, xmlSecTransformMemBufId), -1);
    xmlSecAssert2(transformCtx != NULL, -1);

    buffer = xmlSecTransformMemBufGetBuf(transform);
    xmlSecAssert2(buffer != NULL, -1);
    
    in = &(transform->inBuf);
    out = &(transform->outBuf);    
    inSize = xmlSecBufferGetSize(in);

    if(transform->status == xmlSecTransformStatusNone) {
	transform->status = xmlSecTransformStatusWorking;
    }
    
    if(transform->status == xmlSecTransformStatusWorking) {	
	/* just copy everything from in to our buffer and out */
	ret = xmlSecBufferAppend(buffer, xmlSecBufferGetData(in), inSize);
	if(ret < 0) {
	    xmlSecError(XMLSEC_ERRORS_HERE, 
			xmlSecErrorsSafeString(xmlSecTransformGetName(transform)),
			"xmlSecBufferAppend",
			XMLSEC_ERRORS_R_XMLSEC_FAILED,
			"size=%d", inSize);
	    return(-1);
	}
	
	ret = xmlSecBufferAppend(out, xmlSecBufferGetData(in), inSize);
	if(ret < 0) {
	    xmlSecError(XMLSEC_ERRORS_HERE, 
			xmlSecErrorsSafeString(xmlSecTransformGetName(transform)),
			"xmlSecBufferAppend",
			XMLSEC_ERRORS_R_XMLSEC_FAILED,
			"size=%d", inSize);
	    return(-1);
	}
	
	ret = xmlSecBufferRemoveHead(in, inSize);
	if(ret < 0) {
	    xmlSecError(XMLSEC_ERRORS_HERE, 
			xmlSecErrorsSafeString(xmlSecTransformGetName(transform)),
			"xmlSecBufferRemoveHead",
			XMLSEC_ERRORS_R_XMLSEC_FAILED,
			"size=%d", inSize);
	    return(-1);
	}
	    
	if(last != 0) {
	    transform->status = xmlSecTransformStatusFinished;
	}
    } else if(transform->status == xmlSecTransformStatusFinished) {
	/* the only way we can get here is if there is no input */
	xmlSecAssert2(inSize == 0, -1);
    } else {
	xmlSecError(XMLSEC_ERRORS_HERE, 
		    xmlSecErrorsSafeString(xmlSecTransformGetName(transform)),
		    NULL,
		    XMLSEC_ERRORS_R_INVALID_STATUS,
		    "status=%d", transform->status);
	return(-1);
    }
    return(0);
}