src/MacMessage0.c - third_party/github/cose-wg/COSE-C - Git at Google

 /** \file MacMessage0.c
 * Contains implementation of the functions related to HCOSE_MAC0 handle objects.
 */

 #include <stdlib.h>
 #include <memory.h>
 #include <stdio.h>
 #include <assert.h>
 #include <string.h>

 #include "cose.h"
 #include "cose_int.h"
 #include "configure.h"
 #include "crypto.h"

 COSE * Mac0Root = NULL;

 /*! \private
 * @brief Test if a HCOSE_MAC0 handle is valid
 *
 *  Internal function to test if a MAC0 message handle is valid.
 *  This will start returning invalid results and cause the code to
 *  crash if handles are not released before the memory that underlies them
 *  is deallocated.  This is an issue of a block allocator is used since
 *  in that case it is common to allocate memory but never to de-allocate it
 *  and just do that in a single big block.
 *
 *  @param h handle to be validated
 *  @returns result of check
 */

 bool IsValidMac0Handle(HCOSE_MAC0 h)
 {
 	COSE_Mac0Message * p = (COSE_Mac0Message *)h;
 	return _COSE_IsInList(Mac0Root, (COSE *) p);
 }

 HCOSE_MAC0 COSE_Mac0_Init(COSE_INIT_FLAGS flags, CBOR_CONTEXT_COMMA cose_errback * perr)
 {
 	COSE_Mac0Message * pobj = NULL;

 	CHECK_CONDITION(flags == COSE_INIT_FLAGS_NONE, COSE_ERR_INVALID_PARAMETER);

 	pobj = (COSE_Mac0Message *)COSE_CALLOC(1, sizeof(COSE_Mac0Message), context);
 	CHECK_CONDITION(pobj != NULL, COSE_ERR_OUT_OF_MEMORY);

 	if (!_COSE_Init(flags, &pobj->m_message, COSE_mac0_object, CBOR_CONTEXT_PARAM_COMMA perr)) {
 		goto errorReturn;
 	}

 	_COSE_InsertInList(&Mac0Root, &pobj->m_message);

 	return (HCOSE_MAC0)pobj;

 errorReturn:
 	if (pobj != NULL) {
 		_COSE_Mac0_Release(pobj);
 		COSE_FREE(pobj, context);
 	}
 	return NULL;
 }

 HCOSE_MAC0 _COSE_Mac0_Init_From_Object(cn_cbor * cbor, COSE_Mac0Message * pIn, CBOR_CONTEXT_COMMA cose_errback * perr)
 {
 	COSE_Mac0Message * pobj = pIn;
 	cn_cbor * pRecipients = NULL;
 	// cn_cbor * tmp;
 	cose_errback error = { COSE_ERR_NONE };
 	if (perr == NULL) perr = &error;

 	if (pobj == NULL) pobj = (COSE_Mac0Message *)COSE_CALLOC(1, sizeof(COSE_Mac0Message), context);
 	if (pobj == NULL) {
 		perr->err = COSE_ERR_OUT_OF_MEMORY;
 	errorReturn:
 		if (pobj != NULL) {
 			_COSE_Mac0_Release(pobj);
 			if (pIn == NULL) {
 				COSE_FREE(pobj, context);
 			}
 		}
 		return NULL;
 	}

 	if (!_COSE_Init_From_Object(&pobj->m_message, cbor, CBOR_CONTEXT_PARAM_COMMA perr)) {
 		goto errorReturn;
 	}

 	pRecipients = _COSE_arrayget_int(&pobj->m_message, INDEX_MAC_RECIPIENTS);
 	CHECK_CONDITION(pRecipients == NULL, COSE_ERR_INVALID_PARAMETER);

 	_COSE_InsertInList(&Mac0Root, &pobj->m_message);

 	return(HCOSE_MAC0)pobj;
 }

 bool COSE_Mac0_Free(HCOSE_MAC0 h)
 {
 #ifdef USE_CBOR_CONTEXT
 	cn_cbor_context context;
 #endif
 	COSE_Mac0Message * p = (COSE_Mac0Message *)h;

 	if (!IsValidMac0Handle(h)) return false;

 	if (p->m_message.m_refCount > 1) {
 		p->m_message.m_refCount--;
 		return true;
 	}

 	_COSE_RemoveFromList(&Mac0Root, &p->m_message);

 #ifdef USE_CBOR_CONTEXT
 	context = p->m_message.m_allocContext;
 #endif

 	_COSE_Mac0_Release(p);

 	COSE_FREE(p, &context);

 	return true;
 }

 bool _COSE_Mac0_Release(COSE_Mac0Message * p)
 {
 	_COSE_Release(&p->m_message);

 	return true;
 }

 bool COSE_Mac0_SetContent(HCOSE_MAC0 cose, const byte * rgbContent, size_t cbContent, cose_errback * perr)
 {
 	COSE_Mac0Message * p = (COSE_Mac0Message *)cose;
 #ifdef USE_CBOR_CONTEXT
 	cn_cbor_context * context = &p->m_message.m_allocContext;
 #endif
 	cn_cbor * ptmp = NULL;
 	cn_cbor_errback cbor_error;

 	CHECK_CONDITION(IsValidMac0Handle(cose), COSE_ERR_INVALID_PARAMETER);

 	ptmp = cn_cbor_data_create(rgbContent, (int) cbContent, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	CHECK_CONDITION_CBOR(ptmp != NULL, cbor_error);

 	CHECK_CONDITION_CBOR(_COSE_array_replace(&p->m_message, ptmp, INDEX_BODY, CBOR_CONTEXT_PARAM_COMMA &cbor_error),  cbor_error);
 	ptmp = NULL;

 	return true;

 errorReturn:
 	if (ptmp != NULL) CN_CBOR_FREE(ptmp, context);
 	return false;
 }

 /*!
 * @brief Set the application external data for authentication
 *
 * MAC data objects support the authentication of external application
 * supplied data.  This function is provided to supply that data to the library.
 *
 * The external data is not copied, nor will be it freed when the handle is released.
 *
 * @param hcose  Handle for the COSE MAC data object
 * @param pbEternalData  point to the external data
 * @param cbExternalData size of the external data
 * @param perr  location to return errors
 * @return result of the operation.
 */

 bool COSE_Mac0_SetExternal(HCOSE_MAC0 hcose, const byte * pbExternalData, size_t cbExternalData, cose_errback * perr)
 {
 	if (!IsValidMac0Handle(hcose)) {
 		if (perr != NULL) perr->err = COSE_ERR_INVALID_PARAMETER;
 		return false;
 	}

 	return _COSE_SetExternal(&((COSE_Mac0Message *)hcose)->m_message, pbExternalData, cbExternalData, perr);
 }

 cn_cbor * COSE_Mac0_map_get_int(HCOSE_MAC0 h, int key, int flags, cose_errback * perror)
 {
 	if (!IsValidMac0Handle(h)) {
 		if (perror != NULL) perror->err = COSE_ERR_INVALID_PARAMETER;
 		return NULL;
 	}

 	return _COSE_map_get_int(&((COSE_Mac0Message *)h)->m_message, key, flags, perror);
 }


 bool COSE_Mac0_map_put_int(HCOSE_MAC0 h, int key, cn_cbor * value, int flags, cose_errback * perror)
 {
 	if (!IsValidMac0Handle(h) || (value == NULL)) {
 		if (perror != NULL) perror->err = COSE_ERR_INVALID_PARAMETER;
 		return false;
 	}

 	return _COSE_map_put(&((COSE_Mac0Message *)h)->m_message, key, value, flags, perror);
 }


 bool COSE_Mac0_encrypt(HCOSE_MAC0 h, const byte * pbKey, size_t cbKey, cose_errback * perr)
 {
 	int alg;
 	const cn_cbor * cn_Alg = NULL;
 	byte * pbAuthData = NULL;
 	size_t cbitKey;
 #ifdef USE_CBOR_CONTEXT
 	cn_cbor_context * context = NULL;
 #endif
 	COSE_Mac0Message * pcose = (COSE_Mac0Message *)h;
 	bool fRet = false;
 	size_t cbAuthData;

 	CHECK_CONDITION(IsValidMac0Handle(h), COSE_ERR_INVALID_PARAMETER);

 #ifdef USE_CBOR_CONTEXT
 	context = &pcose->m_message.m_allocContext;
 #endif // USE_CBOR_CONTEXT

 	cn_Alg = _COSE_map_get_int(&pcose->m_message, COSE_Header_Algorithm, COSE_BOTH, perr);
 	if (cn_Alg == NULL) goto errorReturn;
 	CHECK_CONDITION(cn_Alg->type != CN_CBOR_TEXT, COSE_ERR_UNKNOWN_ALGORITHM);
 	CHECK_CONDITION(((cn_Alg->type == CN_CBOR_UINT || cn_Alg->type == CN_CBOR_INT)), COSE_ERR_INVALID_PARAMETER);

 	alg = (int) cn_Alg->v.uint;

 	//  Get the key size

 	switch (alg) {
 	case COSE_Algorithm_CBC_MAC_128_64:
 	case COSE_Algorithm_CBC_MAC_128_128:
 		cbitKey = 128;
 		break;

 	case COSE_Algorithm_CBC_MAC_256_64:
 	case COSE_Algorithm_CBC_MAC_256_128:
 	case COSE_Algorithm_HMAC_256_64:
 	case COSE_Algorithm_HMAC_256_256:
 		cbitKey = 256;
 		break;

 	case COSE_Algorithm_HMAC_384_384:
 		cbitKey = 384;
 		break;

 	case COSE_Algorithm_HMAC_512_512:
 		cbitKey = 512;
 		break;

 	default:
 		FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
 	}

 	//  Build protected headers

 	const cn_cbor * cbProtected = _COSE_encode_protected(&pcose->m_message, perr);
 	if (cbProtected == NULL) goto errorReturn;

 	//  Build authenticated data
 	if (!_COSE_Mac_Build_AAD(&pcose->m_message, "MAC0", &pbAuthData, &cbAuthData, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

 	switch (alg) {
 	case COSE_Algorithm_CBC_MAC_128_64:
 	case COSE_Algorithm_CBC_MAC_256_64:
 		if (!AES_CBC_MAC_Create((COSE_MacMessage *)pcose, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_CBC_MAC_128_128:
 	case COSE_Algorithm_CBC_MAC_256_128:
 		if (!AES_CBC_MAC_Create((COSE_MacMessage *)pcose, 128, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_HMAC_256_64:
 		if (!HMAC_Create((COSE_MacMessage *)pcose, 256, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_HMAC_256_256:
 		if (!HMAC_Create((COSE_MacMessage *)pcose, 256, 256, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_HMAC_384_384:
 		if (!HMAC_Create((COSE_MacMessage *)pcose, 384, 384, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_HMAC_512_512:
 		if (!HMAC_Create((COSE_MacMessage *)pcose, 512, 512, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	default:
 		FAIL_CONDITION(COSE_ERR_INVALID_PARAMETER);
 	}

 	//  Figure out the clean up

 	fRet = true;

 errorReturn:
 	if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);
 	return fRet;
 }

 bool COSE_Mac0_validate(HCOSE_MAC0 h, const byte * pbKey, size_t cbKey, cose_errback * perr)
 {
 	COSE_Mac0Message * pcose = (COSE_Mac0Message *)h;
 	byte * pbAuthData = NULL;
 	int cbitKey = 0;
 	bool fRet = false;
 	int alg;
 	const cn_cbor * cn = NULL;

 #ifdef USE_CBOR_CONTEXT
 	cn_cbor_context * context = NULL;
 #endif
 	size_t cbAuthData;

 	CHECK_CONDITION(IsValidMac0Handle(h), COSE_ERR_INVALID_PARAMETER);

 #ifdef USE_CBOR_CONTEXT
 	context = &pcose->m_message.m_allocContext;
 #endif

 	cn = _COSE_map_get_int(&pcose->m_message, COSE_Header_Algorithm, COSE_BOTH, perr);
 	if (cn == NULL) goto errorReturn;

 	if (cn->type == CN_CBOR_TEXT) {
 			FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
 	}
 	else {
 		CHECK_CONDITION((cn->type == CN_CBOR_UINT || cn->type == CN_CBOR_INT), COSE_ERR_INVALID_PARAMETER);

 		alg = (int)cn->v.uint;

 		switch (alg) {
 		case COSE_Algorithm_CBC_MAC_128_64:
 		case COSE_Algorithm_CBC_MAC_128_128:
 			cbitKey = 128;
 			break;

 		case COSE_Algorithm_CBC_MAC_256_64:
 		case COSE_Algorithm_CBC_MAC_256_128:
 		case COSE_Algorithm_HMAC_256_64:
 		case COSE_Algorithm_HMAC_256_256:
 			cbitKey = 256;
 			break;

 		case COSE_Algorithm_HMAC_384_384:
 			cbitKey = 384;
 			break;

 		case COSE_Algorithm_HMAC_512_512:
 			cbitKey = 512;
 			break;

 		default:
 			FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
 			break;
 		}
 	}

 	//  Build protected headers

 	cn_cbor * cnProtected = _COSE_arrayget_int(&pcose->m_message, INDEX_PROTECTED);
 	CHECK_CONDITION((cnProtected != NULL) && (cnProtected->type == CN_CBOR_BYTES), COSE_ERR_INVALID_PARAMETER);

 	//  Build authenticated data
 	if (!_COSE_Mac_Build_AAD(&pcose->m_message, "MAC0", &pbAuthData, &cbAuthData, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

 	switch (alg) {
 	case COSE_Algorithm_HMAC_256_256:
 		if (!HMAC_Validate((COSE_MacMessage *)pcose, 256, 256, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_HMAC_256_64:
 		if (!HMAC_Validate((COSE_MacMessage *)pcose, 256, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_HMAC_384_384:
 		if (!HMAC_Validate((COSE_MacMessage *)pcose, 384, 384, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_HMAC_512_512:
 		if (!HMAC_Validate((COSE_MacMessage *)pcose, 512, 512, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_CBC_MAC_128_64:
 	case COSE_Algorithm_CBC_MAC_256_64:
 		if (!AES_CBC_MAC_Validate((COSE_MacMessage *)pcose, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	case COSE_Algorithm_CBC_MAC_128_128:
 	case COSE_Algorithm_CBC_MAC_256_128:
 		if (!AES_CBC_MAC_Validate((COSE_MacMessage *)pcose, 128, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
 		break;

 	default:
 		FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
 		break;
 	}

 	fRet = true;

 errorReturn:
 	if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);

 	return fRet;
 }
	/** \file MacMessage0.c
	* Contains implementation of the functions related to HCOSE_MAC0 handle objects.
	*/

	#include <stdlib.h>
	#include <memory.h>
	#include <stdio.h>
	#include <assert.h>
	#include <string.h>

	#include "cose.h"
	#include "cose_int.h"
	#include "configure.h"
	#include "crypto.h"

	COSE * Mac0Root = NULL;

	/*! \private
	* @brief Test if a HCOSE_MAC0 handle is valid
	*
	* Internal function to test if a MAC0 message handle is valid.
	* This will start returning invalid results and cause the code to
	* crash if handles are not released before the memory that underlies them
	* is deallocated. This is an issue of a block allocator is used since
	* in that case it is common to allocate memory but never to de-allocate it
	* and just do that in a single big block.
	*
	* @param h handle to be validated
	* @returns result of check
	*/

	bool IsValidMac0Handle(HCOSE_MAC0 h)
	{
	COSE_Mac0Message * p = (COSE_Mac0Message *)h;
	return _COSE_IsInList(Mac0Root, (COSE *) p);
	}

	HCOSE_MAC0 COSE_Mac0_Init(COSE_INIT_FLAGS flags, CBOR_CONTEXT_COMMA cose_errback * perr)
	{
	COSE_Mac0Message * pobj = NULL;

	CHECK_CONDITION(flags == COSE_INIT_FLAGS_NONE, COSE_ERR_INVALID_PARAMETER);

	pobj = (COSE_Mac0Message *)COSE_CALLOC(1, sizeof(COSE_Mac0Message), context);
	CHECK_CONDITION(pobj != NULL, COSE_ERR_OUT_OF_MEMORY);

	if (!_COSE_Init(flags, &pobj->m_message, COSE_mac0_object, CBOR_CONTEXT_PARAM_COMMA perr)) {
	goto errorReturn;
	}

	_COSE_InsertInList(&Mac0Root, &pobj->m_message);

	return (HCOSE_MAC0)pobj;

	errorReturn:
	if (pobj != NULL) {
	_COSE_Mac0_Release(pobj);
	COSE_FREE(pobj, context);
	}
	return NULL;
	}

	HCOSE_MAC0 _COSE_Mac0_Init_From_Object(cn_cbor * cbor, COSE_Mac0Message * pIn, CBOR_CONTEXT_COMMA cose_errback * perr)
	{
	COSE_Mac0Message * pobj = pIn;
	cn_cbor * pRecipients = NULL;
	// cn_cbor * tmp;
	cose_errback error = { COSE_ERR_NONE };
	if (perr == NULL) perr = &error;

	if (pobj == NULL) pobj = (COSE_Mac0Message *)COSE_CALLOC(1, sizeof(COSE_Mac0Message), context);
	if (pobj == NULL) {
	perr->err = COSE_ERR_OUT_OF_MEMORY;
	errorReturn:
	if (pobj != NULL) {
	_COSE_Mac0_Release(pobj);
	if (pIn == NULL) {
	COSE_FREE(pobj, context);
	}
	}
	return NULL;
	}

	if (!_COSE_Init_From_Object(&pobj->m_message, cbor, CBOR_CONTEXT_PARAM_COMMA perr)) {
	goto errorReturn;
	}

	pRecipients = _COSE_arrayget_int(&pobj->m_message, INDEX_MAC_RECIPIENTS);
	CHECK_CONDITION(pRecipients == NULL, COSE_ERR_INVALID_PARAMETER);

	_COSE_InsertInList(&Mac0Root, &pobj->m_message);

	return(HCOSE_MAC0)pobj;
	}

	bool COSE_Mac0_Free(HCOSE_MAC0 h)
	{
	#ifdef USE_CBOR_CONTEXT
	cn_cbor_context context;
	#endif
	COSE_Mac0Message * p = (COSE_Mac0Message *)h;

	if (!IsValidMac0Handle(h)) return false;

	if (p->m_message.m_refCount > 1) {
	p->m_message.m_refCount--;
	return true;
	}

	_COSE_RemoveFromList(&Mac0Root, &p->m_message);

	#ifdef USE_CBOR_CONTEXT
	context = p->m_message.m_allocContext;
	#endif

	_COSE_Mac0_Release(p);

	COSE_FREE(p, &context);

	return true;
	}

	bool _COSE_Mac0_Release(COSE_Mac0Message * p)
	{
	_COSE_Release(&p->m_message);

	return true;
	}

	bool COSE_Mac0_SetContent(HCOSE_MAC0 cose, const byte * rgbContent, size_t cbContent, cose_errback * perr)
	{
	COSE_Mac0Message * p = (COSE_Mac0Message *)cose;
	#ifdef USE_CBOR_CONTEXT
	cn_cbor_context * context = &p->m_message.m_allocContext;
	#endif
	cn_cbor * ptmp = NULL;
	cn_cbor_errback cbor_error;

	CHECK_CONDITION(IsValidMac0Handle(cose), COSE_ERR_INVALID_PARAMETER);

	ptmp = cn_cbor_data_create(rgbContent, (int) cbContent, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	CHECK_CONDITION_CBOR(ptmp != NULL, cbor_error);

	CHECK_CONDITION_CBOR(_COSE_array_replace(&p->m_message, ptmp, INDEX_BODY, CBOR_CONTEXT_PARAM_COMMA &cbor_error), cbor_error);
	ptmp = NULL;

	return true;

	errorReturn:
	if (ptmp != NULL) CN_CBOR_FREE(ptmp, context);
	return false;
	}

	/*!
	* @brief Set the application external data for authentication
	*
	* MAC data objects support the authentication of external application
	* supplied data. This function is provided to supply that data to the library.
	*
	* The external data is not copied, nor will be it freed when the handle is released.
	*
	* @param hcose Handle for the COSE MAC data object
	* @param pbEternalData point to the external data
	* @param cbExternalData size of the external data
	* @param perr location to return errors
	* @return result of the operation.
	*/

	bool COSE_Mac0_SetExternal(HCOSE_MAC0 hcose, const byte * pbExternalData, size_t cbExternalData, cose_errback * perr)
	{
	if (!IsValidMac0Handle(hcose)) {
	if (perr != NULL) perr->err = COSE_ERR_INVALID_PARAMETER;
	return false;
	}

	return _COSE_SetExternal(&((COSE_Mac0Message *)hcose)->m_message, pbExternalData, cbExternalData, perr);
	}

	cn_cbor * COSE_Mac0_map_get_int(HCOSE_MAC0 h, int key, int flags, cose_errback * perror)
	{
	if (!IsValidMac0Handle(h)) {
	if (perror != NULL) perror->err = COSE_ERR_INVALID_PARAMETER;
	return NULL;
	}

	return _COSE_map_get_int(&((COSE_Mac0Message *)h)->m_message, key, flags, perror);
	}


	bool COSE_Mac0_map_put_int(HCOSE_MAC0 h, int key, cn_cbor * value, int flags, cose_errback * perror)
	{
	if (!IsValidMac0Handle(h) \|\| (value == NULL)) {
	if (perror != NULL) perror->err = COSE_ERR_INVALID_PARAMETER;
	return false;
	}

	return _COSE_map_put(&((COSE_Mac0Message *)h)->m_message, key, value, flags, perror);
	}


	bool COSE_Mac0_encrypt(HCOSE_MAC0 h, const byte * pbKey, size_t cbKey, cose_errback * perr)
	{
	int alg;
	const cn_cbor * cn_Alg = NULL;
	byte * pbAuthData = NULL;
	size_t cbitKey;
	#ifdef USE_CBOR_CONTEXT
	cn_cbor_context * context = NULL;
	#endif
	COSE_Mac0Message * pcose = (COSE_Mac0Message *)h;
	bool fRet = false;
	size_t cbAuthData;

	CHECK_CONDITION(IsValidMac0Handle(h), COSE_ERR_INVALID_PARAMETER);

	#ifdef USE_CBOR_CONTEXT
	context = &pcose->m_message.m_allocContext;
	#endif // USE_CBOR_CONTEXT

	cn_Alg = _COSE_map_get_int(&pcose->m_message, COSE_Header_Algorithm, COSE_BOTH, perr);
	if (cn_Alg == NULL) goto errorReturn;
	CHECK_CONDITION(cn_Alg->type != CN_CBOR_TEXT, COSE_ERR_UNKNOWN_ALGORITHM);
	CHECK_CONDITION(((cn_Alg->type == CN_CBOR_UINT \|\| cn_Alg->type == CN_CBOR_INT)), COSE_ERR_INVALID_PARAMETER);

	alg = (int) cn_Alg->v.uint;

	// Get the key size

	switch (alg) {
	case COSE_Algorithm_CBC_MAC_128_64:
	case COSE_Algorithm_CBC_MAC_128_128:
	cbitKey = 128;
	break;

	case COSE_Algorithm_CBC_MAC_256_64:
	case COSE_Algorithm_CBC_MAC_256_128:
	case COSE_Algorithm_HMAC_256_64:
	case COSE_Algorithm_HMAC_256_256:
	cbitKey = 256;
	break;

	case COSE_Algorithm_HMAC_384_384:
	cbitKey = 384;
	break;

	case COSE_Algorithm_HMAC_512_512:
	cbitKey = 512;
	break;

	default:
	FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
	}

	// Build protected headers

	const cn_cbor * cbProtected = _COSE_encode_protected(&pcose->m_message, perr);
	if (cbProtected == NULL) goto errorReturn;

	// Build authenticated data
	if (!_COSE_Mac_Build_AAD(&pcose->m_message, "MAC0", &pbAuthData, &cbAuthData, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

	switch (alg) {
	case COSE_Algorithm_CBC_MAC_128_64:
	case COSE_Algorithm_CBC_MAC_256_64:
	if (!AES_CBC_MAC_Create((COSE_MacMessage *)pcose, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_CBC_MAC_128_128:
	case COSE_Algorithm_CBC_MAC_256_128:
	if (!AES_CBC_MAC_Create((COSE_MacMessage *)pcose, 128, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_HMAC_256_64:
	if (!HMAC_Create((COSE_MacMessage *)pcose, 256, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_HMAC_256_256:
	if (!HMAC_Create((COSE_MacMessage *)pcose, 256, 256, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_HMAC_384_384:
	if (!HMAC_Create((COSE_MacMessage *)pcose, 384, 384, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_HMAC_512_512:
	if (!HMAC_Create((COSE_MacMessage *)pcose, 512, 512, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	default:
	FAIL_CONDITION(COSE_ERR_INVALID_PARAMETER);
	}

	// Figure out the clean up

	fRet = true;

	errorReturn:
	if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);
	return fRet;
	}

	bool COSE_Mac0_validate(HCOSE_MAC0 h, const byte * pbKey, size_t cbKey, cose_errback * perr)
	{
	COSE_Mac0Message * pcose = (COSE_Mac0Message *)h;
	byte * pbAuthData = NULL;
	int cbitKey = 0;
	bool fRet = false;
	int alg;
	const cn_cbor * cn = NULL;

	#ifdef USE_CBOR_CONTEXT
	cn_cbor_context * context = NULL;
	#endif
	size_t cbAuthData;

	CHECK_CONDITION(IsValidMac0Handle(h), COSE_ERR_INVALID_PARAMETER);

	#ifdef USE_CBOR_CONTEXT
	context = &pcose->m_message.m_allocContext;
	#endif

	cn = _COSE_map_get_int(&pcose->m_message, COSE_Header_Algorithm, COSE_BOTH, perr);
	if (cn == NULL) goto errorReturn;

	if (cn->type == CN_CBOR_TEXT) {
	FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
	}
	else {
	CHECK_CONDITION((cn->type == CN_CBOR_UINT \|\| cn->type == CN_CBOR_INT), COSE_ERR_INVALID_PARAMETER);

	alg = (int)cn->v.uint;

	switch (alg) {
	case COSE_Algorithm_CBC_MAC_128_64:
	case COSE_Algorithm_CBC_MAC_128_128:
	cbitKey = 128;
	break;

	case COSE_Algorithm_CBC_MAC_256_64:
	case COSE_Algorithm_CBC_MAC_256_128:
	case COSE_Algorithm_HMAC_256_64:
	case COSE_Algorithm_HMAC_256_256:
	cbitKey = 256;
	break;

	case COSE_Algorithm_HMAC_384_384:
	cbitKey = 384;
	break;

	case COSE_Algorithm_HMAC_512_512:
	cbitKey = 512;
	break;

	default:
	FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
	break;
	}
	}

	// Build protected headers

	cn_cbor * cnProtected = _COSE_arrayget_int(&pcose->m_message, INDEX_PROTECTED);
	CHECK_CONDITION((cnProtected != NULL) && (cnProtected->type == CN_CBOR_BYTES), COSE_ERR_INVALID_PARAMETER);

	// Build authenticated data
	if (!_COSE_Mac_Build_AAD(&pcose->m_message, "MAC0", &pbAuthData, &cbAuthData, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

	switch (alg) {
	case COSE_Algorithm_HMAC_256_256:
	if (!HMAC_Validate((COSE_MacMessage *)pcose, 256, 256, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_HMAC_256_64:
	if (!HMAC_Validate((COSE_MacMessage *)pcose, 256, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_HMAC_384_384:
	if (!HMAC_Validate((COSE_MacMessage *)pcose, 384, 384, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_HMAC_512_512:
	if (!HMAC_Validate((COSE_MacMessage *)pcose, 512, 512, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_CBC_MAC_128_64:
	case COSE_Algorithm_CBC_MAC_256_64:
	if (!AES_CBC_MAC_Validate((COSE_MacMessage *)pcose, 64, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	case COSE_Algorithm_CBC_MAC_128_128:
	case COSE_Algorithm_CBC_MAC_256_128:
	if (!AES_CBC_MAC_Validate((COSE_MacMessage *)pcose, 128, pbKey, cbKey, pbAuthData, cbAuthData, perr)) goto errorReturn;
	break;

	default:
	FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
	break;
	}

	fRet = true;

	errorReturn:
	if (pbAuthData != NULL) COSE_FREE(pbAuthData, context);

	return fRet;
	}