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

 /** \file SignerInfo.c
 * Contains implementation of the functions related to HCOSE_SIGNER handle objects.
 */

 #include <stdlib.h>
 #ifndef __MBED__
 #include <memory.h>
 #endif

 #include "cose/cose.h"
 #include "cose_int.h"
 #include "cose/cose_configure.h"
 #include "crypto.h"

 #if INCLUDE_SIGN

 extern bool IsValidSignHandle(HCOSE_SIGN h);

 COSE * SignerRoot = NULL;

 bool IsValidSignerHandle(HCOSE_SIGNER h)
 {
 	COSE_SignerInfo * p = (COSE_SignerInfo *)h;
 	return _COSE_IsInList(SignerRoot, (COSE *) p);
 }


 bool _COSE_SignerInfo_Free(COSE_SignerInfo * pSigner)
 {
 	//  Check ref counting
 	if (pSigner->m_message.m_refCount > 1) {
 		pSigner->m_message.m_refCount--;
 		return true;
 	}

 	_COSE_Release(&pSigner->m_message);

 	return true;
 }

 bool COSE_Signer_Free(HCOSE_SIGNER hSigner)
 {
 	COSE_SignerInfo * pSigner = (COSE_SignerInfo *)hSigner;
 	bool fRet = false;

 	if (!IsValidSignerHandle(hSigner)) goto errorReturn;

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

 	_COSE_SignerInfo_Free(pSigner);

 	_COSE_RemoveFromList(&SignerRoot, &pSigner->m_message);

 	COSE_FREE(pSigner, &pSigner->m_message.m_allocContext);

 	fRet = true;
 errorReturn:
 	return fRet;
 }


 HCOSE_SIGNER COSE_Signer_Init(CBOR_CONTEXT_COMMA cose_errback * perror)
 {
 	COSE_SignerInfo * pobj = (COSE_SignerInfo *)COSE_CALLOC(1, sizeof(COSE_SignerInfo), context);
 	if (pobj == NULL) {
 		if (perror != NULL) perror->err = COSE_ERR_OUT_OF_MEMORY;
 		return NULL;
 	}

 	if (!_COSE_SignerInfo_Init(COSE_INIT_FLAGS_NO_CBOR_TAG, pobj, COSE_recipient_object, CBOR_CONTEXT_PARAM_COMMA perror)) {
 		_COSE_SignerInfo_Free(pobj);
 		COSE_FREE(pobj, context);
 		return NULL;
 	}

 	_COSE_InsertInList(&SignerRoot, &pobj->m_message);
 	return (HCOSE_SIGNER)pobj;
 }

 bool _COSE_SignerInfo_Init(COSE_INIT_FLAGS flags, COSE_SignerInfo * pobj, int msgType, CBOR_CONTEXT_COMMA cose_errback * errp)
 {
 	return _COSE_Init(flags, &pobj->m_message, msgType, CBOR_CONTEXT_PARAM_COMMA errp);
 }


 COSE_SignerInfo * _COSE_SignerInfo_Init_From_Object(cn_cbor * cbor, COSE_SignerInfo * pIn, CBOR_CONTEXT_COMMA cose_errback * perr)
 {
 	COSE_SignerInfo * pSigner = pIn;

 	if (pSigner == NULL) {
 		pSigner = (COSE_SignerInfo *)COSE_CALLOC(1, sizeof(COSE_SignerInfo), context);
 		CHECK_CONDITION(pSigner != NULL, COSE_ERR_OUT_OF_MEMORY);
 	}

 	CHECK_CONDITION(cbor->type == CN_CBOR_ARRAY, COSE_ERR_INVALID_PARAMETER);

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

 	_COSE_InsertInList(&SignerRoot, &pSigner->m_message);
 	return pSigner;

 errorReturn:
 	if (pSigner != NULL) {
 		_COSE_SignerInfo_Free(pSigner);
 		if (pIn == NULL) COSE_FREE(pSigner, context);
 	}
 	return NULL;
 }

 bool BuildToBeSigned(byte ** ppbToSign, size_t * pcbToSign, const cn_cbor * pcborBody, const cn_cbor * pcborProtected, const cn_cbor * pcborProtectedSign, const byte * pbExternal, size_t cbExternal, CBOR_CONTEXT_COMMA cose_errback * perr)
 {
 	cn_cbor * pArray = NULL;
 	cn_cbor_errback cbor_error;
 	size_t cbToSign;
 	byte * pbToSign = NULL;
 	bool f = false;
 	cn_cbor * cn = NULL;

 	pArray = cn_cbor_array_create(CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	CHECK_CONDITION_CBOR(pArray != NULL, cbor_error);

 	cn = cn_cbor_string_create("Signature", CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
 	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
 	cn = NULL;

 	if (pcborProtected->length == 1 && (pcborProtected->v.bytes[0] == 0xa0)) cn = cn_cbor_data_create(NULL, 0, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	else cn = cn_cbor_data_create(pcborProtected->v.bytes, (int)pcborProtected->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
 	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
 	cn = NULL;

 	if ((pcborProtectedSign->length == 1) && (pcborProtectedSign->v.bytes[0] == 0xa0)) cn = cn_cbor_data_create(NULL, 0, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	else cn = cn_cbor_data_create(pcborProtectedSign->v.bytes, (int)pcborProtectedSign->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
 	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
 	cn = NULL;

 	cn = cn_cbor_data_create(pbExternal, (int) cbExternal, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
 	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
 	cn = NULL;

 	cn = cn_cbor_data_create(pcborBody->v.bytes, (int)pcborBody->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
 	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
 	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
 	cn = NULL;

 	cbToSign = cn_cbor_encode_size(pArray);
 	CHECK_CONDITION(cbToSign > 0, COSE_ERR_CBOR);
 	pbToSign = (byte *)COSE_CALLOC(cbToSign, 1, context);
 	CHECK_CONDITION(pbToSign != NULL, COSE_ERR_OUT_OF_MEMORY);
 	CHECK_CONDITION(cn_cbor_encoder_write(pbToSign, 0, cbToSign, pArray) == cbToSign, COSE_ERR_CBOR);

 	*ppbToSign = pbToSign;
 	*pcbToSign = cbToSign;
 	pbToSign = NULL;
 	f = true;

 errorReturn:
 	if (cn != NULL) CN_CBOR_FREE(cn, context);
 	if (pArray != NULL) CN_CBOR_FREE(pArray, context);
 	if (pbToSign != NULL) COSE_FREE(pbToSign, context);
 	return f;

 }


 bool _COSE_Signer_sign(COSE_SignerInfo * pSigner, const cn_cbor * pcborBody, const cn_cbor * pcborProtected, cose_errback * perr)
 {
 #ifdef USE_CBOR_CONTEXT
 	cn_cbor_context * context = &pSigner->m_message.m_allocContext;
 #endif
 	cn_cbor * pcborProtectedSign = NULL;
 	cn_cbor * pArray = NULL;
 	cn_cbor * cnAlgorithm = NULL;
 	size_t cbToSign;
 	byte * pbToSign = NULL;
 	int alg;
 	bool fRet = false;

 	pArray = cn_cbor_array_create(CBOR_CONTEXT_PARAM_COMMA NULL);
 	CHECK_CONDITION(pArray != NULL, COSE_ERR_OUT_OF_MEMORY);

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

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

 		alg = (int)cnAlgorithm->v.sint;
 	}

 	pcborProtectedSign = _COSE_encode_protected(&pSigner->m_message, perr);
 	if (pcborProtectedSign == NULL) goto errorReturn;

 	if (!BuildToBeSigned(&pbToSign, &cbToSign, pcborBody, pcborProtected, pcborProtectedSign, pSigner->m_message.m_pbExternal, pSigner->m_message.m_cbExternal, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

 	switch (alg) {
 #ifdef USE_ECDSA_SHA_256
 	case COSE_Algorithm_ECDSA_SHA_256:
 		if (!ECDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 256, pbToSign, cbToSign, perr)) goto errorReturn;
 		break;
 #endif

 #ifdef USE_ECDSA_SHA_384
 	case COSE_Algorithm_ECDSA_SHA_384:
 		if (!ECDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 384, pbToSign, cbToSign, perr)) goto errorReturn;
 		break;
 #endif

 #ifdef USE_ECDSA_SHA_512
 	case COSE_Algorithm_ECDSA_SHA_512:
 		if (!ECDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 512, pbToSign, cbToSign, perr)) goto errorReturn;
 		break;
 #endif

 #ifdef USE_EDDSA
 	case COSE_Algorithm_EdDSA:
 		if (!EdDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, pbToSign, cbToSign, perr)) goto errorReturn;
 		break;
 #endif

 	default:
 		FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
 	}

 	fRet = true;

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

 bool COSE_Signer_SetKey(HCOSE_SIGNER h, const cn_cbor * pKey, cose_errback * perr)
 {
 	COSE_SignerInfo * p;
 	bool fRet = false;

 	CHECK_CONDITION(IsValidSignerHandle(h), COSE_ERR_INVALID_HANDLE);
 	CHECK_CONDITION(pKey != NULL, COSE_ERR_INVALID_PARAMETER);

 	p = (COSE_SignerInfo *)h;
 	p->m_pkey = pKey;

 	fRet = true;
 errorReturn:
 	return fRet;
 }

 /*!
 * @brief Set the application external data for authentication
 *
 * Signer 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_Signer_SetExternal(HCOSE_SIGNER hcose, const byte * pbExternalData, size_t cbExternalData, cose_errback * perr)
 {
 	if (!IsValidSignerHandle(hcose)) {
 		if (perr != NULL) perr->err = COSE_ERR_INVALID_HANDLE;
 		return false;
 	}

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


 bool _COSE_Signer_validate(COSE_SignMessage * pSign, COSE_SignerInfo * pSigner, const cn_cbor * pcborBody, const cn_cbor * pcborProtected, cose_errback * perr)
 {
 	byte * pbToBeSigned = NULL;
 	int alg;
 	const cn_cbor * cn = NULL;
 #ifdef USE_CBOR_CONTEXT
 	cn_cbor_context * context = NULL;
 #endif
 	size_t cbToBeSigned;
 	bool fRet = false;

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

 	cn = _COSE_map_get_int(&pSigner->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.sint;
 	}

 	//  Build protected headers


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

 	//  Build authenticated data
 	if (!BuildToBeSigned(&pbToBeSigned, &cbToBeSigned, pcborBody, pcborProtected, cnProtected, pSigner->m_message.m_pbExternal, pSigner->m_message.m_cbExternal, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

 	cn_cbor * cnSignature = _COSE_arrayget_int(&pSigner->m_message, INDEX_SIGNATURE);
 	CHECK_CONDITION((cnSignature != NULL) && (cnSignature->type == CN_CBOR_BYTES), COSE_ERR_INVALID_PARAMETER);

 	switch (alg) {
 #ifdef USE_ECDSA_SHA_256
 	case COSE_Algorithm_ECDSA_SHA_256:
 		if (!ECDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 256, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
 		break;
 #endif

 #ifdef USE_ECDSA_SHA_384
 	case COSE_Algorithm_ECDSA_SHA_384:
 		if (!ECDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 384, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
 		break;
 #endif

 #ifdef USE_ECDSA_SHA_512
 	case COSE_Algorithm_ECDSA_SHA_512:
 		if (!ECDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 512, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
 		break;
 #endif

 #ifdef USE_EDDSA
 	case COSE_Algorithm_EdDSA:
 		if (!EdDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
 		break;
 #endif

 	default:
 		FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
 		break;
 	}

 	fRet = true;

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

 	return fRet;
 }

 cn_cbor * COSE_Signer_map_get_int(HCOSE_SIGNER h, int key, int flags, cose_errback * perr)
 {
 	if (!IsValidSignerHandle(h)) {
 		if (perr != NULL) perr->err = COSE_ERR_INVALID_HANDLE;
 		return NULL;
 	}

 	return _COSE_map_get_int((COSE *)h, key, flags, perr);
 }

 bool COSE_Signer_map_put_int(HCOSE_SIGNER h, int key, cn_cbor * value, int flags, cose_errback * perr)
 {
 	bool fRet = false;

 	CHECK_CONDITION(IsValidSignerHandle(h), COSE_ERR_INVALID_HANDLE);
 	CHECK_CONDITION(value != NULL, COSE_ERR_INVALID_PARAMETER);

 	return _COSE_map_put(&((COSE_SignerInfo *)h)->m_message, key, value, flags, perr);

 errorReturn:
 	return fRet;
 }

 #endif
	/** \file SignerInfo.c
	* Contains implementation of the functions related to HCOSE_SIGNER handle objects.
	*/

	#include <stdlib.h>
	#ifndef __MBED__
	#include <memory.h>
	#endif

	#include "cose/cose.h"
	#include "cose_int.h"
	#include "cose/cose_configure.h"
	#include "crypto.h"

	#if INCLUDE_SIGN

	extern bool IsValidSignHandle(HCOSE_SIGN h);

	COSE * SignerRoot = NULL;

	bool IsValidSignerHandle(HCOSE_SIGNER h)
	{
	COSE_SignerInfo * p = (COSE_SignerInfo *)h;
	return _COSE_IsInList(SignerRoot, (COSE *) p);
	}


	bool _COSE_SignerInfo_Free(COSE_SignerInfo * pSigner)
	{
	// Check ref counting
	if (pSigner->m_message.m_refCount > 1) {
	pSigner->m_message.m_refCount--;
	return true;
	}

	_COSE_Release(&pSigner->m_message);

	return true;
	}

	bool COSE_Signer_Free(HCOSE_SIGNER hSigner)
	{
	COSE_SignerInfo * pSigner = (COSE_SignerInfo *)hSigner;
	bool fRet = false;

	if (!IsValidSignerHandle(hSigner)) goto errorReturn;

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

	_COSE_SignerInfo_Free(pSigner);

	_COSE_RemoveFromList(&SignerRoot, &pSigner->m_message);

	COSE_FREE(pSigner, &pSigner->m_message.m_allocContext);

	fRet = true;
	errorReturn:
	return fRet;
	}


	HCOSE_SIGNER COSE_Signer_Init(CBOR_CONTEXT_COMMA cose_errback * perror)
	{
	COSE_SignerInfo * pobj = (COSE_SignerInfo *)COSE_CALLOC(1, sizeof(COSE_SignerInfo), context);
	if (pobj == NULL) {
	if (perror != NULL) perror->err = COSE_ERR_OUT_OF_MEMORY;
	return NULL;
	}

	if (!_COSE_SignerInfo_Init(COSE_INIT_FLAGS_NO_CBOR_TAG, pobj, COSE_recipient_object, CBOR_CONTEXT_PARAM_COMMA perror)) {
	_COSE_SignerInfo_Free(pobj);
	COSE_FREE(pobj, context);
	return NULL;
	}

	_COSE_InsertInList(&SignerRoot, &pobj->m_message);
	return (HCOSE_SIGNER)pobj;
	}

	bool _COSE_SignerInfo_Init(COSE_INIT_FLAGS flags, COSE_SignerInfo * pobj, int msgType, CBOR_CONTEXT_COMMA cose_errback * errp)
	{
	return _COSE_Init(flags, &pobj->m_message, msgType, CBOR_CONTEXT_PARAM_COMMA errp);
	}


	COSE_SignerInfo * _COSE_SignerInfo_Init_From_Object(cn_cbor * cbor, COSE_SignerInfo * pIn, CBOR_CONTEXT_COMMA cose_errback * perr)
	{
	COSE_SignerInfo * pSigner = pIn;

	if (pSigner == NULL) {
	pSigner = (COSE_SignerInfo *)COSE_CALLOC(1, sizeof(COSE_SignerInfo), context);
	CHECK_CONDITION(pSigner != NULL, COSE_ERR_OUT_OF_MEMORY);
	}

	CHECK_CONDITION(cbor->type == CN_CBOR_ARRAY, COSE_ERR_INVALID_PARAMETER);

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

	_COSE_InsertInList(&SignerRoot, &pSigner->m_message);
	return pSigner;

	errorReturn:
	if (pSigner != NULL) {
	_COSE_SignerInfo_Free(pSigner);
	if (pIn == NULL) COSE_FREE(pSigner, context);
	}
	return NULL;
	}

	bool BuildToBeSigned(byte ** ppbToSign, size_t * pcbToSign, const cn_cbor * pcborBody, const cn_cbor * pcborProtected, const cn_cbor * pcborProtectedSign, const byte * pbExternal, size_t cbExternal, CBOR_CONTEXT_COMMA cose_errback * perr)
	{
	cn_cbor * pArray = NULL;
	cn_cbor_errback cbor_error;
	size_t cbToSign;
	byte * pbToSign = NULL;
	bool f = false;
	cn_cbor * cn = NULL;

	pArray = cn_cbor_array_create(CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	CHECK_CONDITION_CBOR(pArray != NULL, cbor_error);

	cn = cn_cbor_string_create("Signature", CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
	cn = NULL;

	if (pcborProtected->length == 1 && (pcborProtected->v.bytes[0] == 0xa0)) cn = cn_cbor_data_create(NULL, 0, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	else cn = cn_cbor_data_create(pcborProtected->v.bytes, (int)pcborProtected->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
	cn = NULL;

	if ((pcborProtectedSign->length == 1) && (pcborProtectedSign->v.bytes[0] == 0xa0)) cn = cn_cbor_data_create(NULL, 0, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	else cn = cn_cbor_data_create(pcborProtectedSign->v.bytes, (int)pcborProtectedSign->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
	cn = NULL;

	cn = cn_cbor_data_create(pbExternal, (int) cbExternal, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
	cn = NULL;

	cn = cn_cbor_data_create(pcborBody->v.bytes, (int)pcborBody->length, CBOR_CONTEXT_PARAM_COMMA &cbor_error);
	CHECK_CONDITION_CBOR(cn != NULL, cbor_error);
	CHECK_CONDITION_CBOR(cn_cbor_array_append(pArray, cn, &cbor_error), cbor_error);
	cn = NULL;

	cbToSign = cn_cbor_encode_size(pArray);
	CHECK_CONDITION(cbToSign > 0, COSE_ERR_CBOR);
	pbToSign = (byte *)COSE_CALLOC(cbToSign, 1, context);
	CHECK_CONDITION(pbToSign != NULL, COSE_ERR_OUT_OF_MEMORY);
	CHECK_CONDITION(cn_cbor_encoder_write(pbToSign, 0, cbToSign, pArray) == cbToSign, COSE_ERR_CBOR);

	*ppbToSign = pbToSign;
	*pcbToSign = cbToSign;
	pbToSign = NULL;
	f = true;

	errorReturn:
	if (cn != NULL) CN_CBOR_FREE(cn, context);
	if (pArray != NULL) CN_CBOR_FREE(pArray, context);
	if (pbToSign != NULL) COSE_FREE(pbToSign, context);
	return f;

	}


	bool _COSE_Signer_sign(COSE_SignerInfo * pSigner, const cn_cbor * pcborBody, const cn_cbor * pcborProtected, cose_errback * perr)
	{
	#ifdef USE_CBOR_CONTEXT
	cn_cbor_context * context = &pSigner->m_message.m_allocContext;
	#endif
	cn_cbor * pcborProtectedSign = NULL;
	cn_cbor * pArray = NULL;
	cn_cbor * cnAlgorithm = NULL;
	size_t cbToSign;
	byte * pbToSign = NULL;
	int alg;
	bool fRet = false;

	pArray = cn_cbor_array_create(CBOR_CONTEXT_PARAM_COMMA NULL);
	CHECK_CONDITION(pArray != NULL, COSE_ERR_OUT_OF_MEMORY);

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

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

	alg = (int)cnAlgorithm->v.sint;
	}

	pcborProtectedSign = _COSE_encode_protected(&pSigner->m_message, perr);
	if (pcborProtectedSign == NULL) goto errorReturn;

	if (!BuildToBeSigned(&pbToSign, &cbToSign, pcborBody, pcborProtected, pcborProtectedSign, pSigner->m_message.m_pbExternal, pSigner->m_message.m_cbExternal, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

	switch (alg) {
	#ifdef USE_ECDSA_SHA_256
	case COSE_Algorithm_ECDSA_SHA_256:
	if (!ECDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 256, pbToSign, cbToSign, perr)) goto errorReturn;
	break;
	#endif

	#ifdef USE_ECDSA_SHA_384
	case COSE_Algorithm_ECDSA_SHA_384:
	if (!ECDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 384, pbToSign, cbToSign, perr)) goto errorReturn;
	break;
	#endif

	#ifdef USE_ECDSA_SHA_512
	case COSE_Algorithm_ECDSA_SHA_512:
	if (!ECDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 512, pbToSign, cbToSign, perr)) goto errorReturn;
	break;
	#endif

	#ifdef USE_EDDSA
	case COSE_Algorithm_EdDSA:
	if (!EdDSA_Sign(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, pbToSign, cbToSign, perr)) goto errorReturn;
	break;
	#endif

	default:
	FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
	}

	fRet = true;

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

	bool COSE_Signer_SetKey(HCOSE_SIGNER h, const cn_cbor * pKey, cose_errback * perr)
	{
	COSE_SignerInfo * p;
	bool fRet = false;

	CHECK_CONDITION(IsValidSignerHandle(h), COSE_ERR_INVALID_HANDLE);
	CHECK_CONDITION(pKey != NULL, COSE_ERR_INVALID_PARAMETER);

	p = (COSE_SignerInfo *)h;
	p->m_pkey = pKey;

	fRet = true;
	errorReturn:
	return fRet;
	}

	/*!
	* @brief Set the application external data for authentication
	*
	* Signer 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_Signer_SetExternal(HCOSE_SIGNER hcose, const byte * pbExternalData, size_t cbExternalData, cose_errback * perr)
	{
	if (!IsValidSignerHandle(hcose)) {
	if (perr != NULL) perr->err = COSE_ERR_INVALID_HANDLE;
	return false;
	}

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


	bool _COSE_Signer_validate(COSE_SignMessage * pSign, COSE_SignerInfo * pSigner, const cn_cbor * pcborBody, const cn_cbor * pcborProtected, cose_errback * perr)
	{
	byte * pbToBeSigned = NULL;
	int alg;
	const cn_cbor * cn = NULL;
	#ifdef USE_CBOR_CONTEXT
	cn_cbor_context * context = NULL;
	#endif
	size_t cbToBeSigned;
	bool fRet = false;

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

	cn = _COSE_map_get_int(&pSigner->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.sint;
	}

	// Build protected headers


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

	// Build authenticated data
	if (!BuildToBeSigned(&pbToBeSigned, &cbToBeSigned, pcborBody, pcborProtected, cnProtected, pSigner->m_message.m_pbExternal, pSigner->m_message.m_cbExternal, CBOR_CONTEXT_PARAM_COMMA perr)) goto errorReturn;

	cn_cbor * cnSignature = _COSE_arrayget_int(&pSigner->m_message, INDEX_SIGNATURE);
	CHECK_CONDITION((cnSignature != NULL) && (cnSignature->type == CN_CBOR_BYTES), COSE_ERR_INVALID_PARAMETER);

	switch (alg) {
	#ifdef USE_ECDSA_SHA_256
	case COSE_Algorithm_ECDSA_SHA_256:
	if (!ECDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 256, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
	break;
	#endif

	#ifdef USE_ECDSA_SHA_384
	case COSE_Algorithm_ECDSA_SHA_384:
	if (!ECDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 384, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
	break;
	#endif

	#ifdef USE_ECDSA_SHA_512
	case COSE_Algorithm_ECDSA_SHA_512:
	if (!ECDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, 512, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
	break;
	#endif

	#ifdef USE_EDDSA
	case COSE_Algorithm_EdDSA:
	if (!EdDSA_Verify(&pSigner->m_message, INDEX_SIGNATURE, pSigner->m_pkey, pbToBeSigned, cbToBeSigned, perr)) goto errorReturn;
	break;
	#endif

	default:
	FAIL_CONDITION(COSE_ERR_UNKNOWN_ALGORITHM);
	break;
	}

	fRet = true;

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

	return fRet;
	}

	cn_cbor * COSE_Signer_map_get_int(HCOSE_SIGNER h, int key, int flags, cose_errback * perr)
	{
	if (!IsValidSignerHandle(h)) {
	if (perr != NULL) perr->err = COSE_ERR_INVALID_HANDLE;
	return NULL;
	}

	return _COSE_map_get_int((COSE *)h, key, flags, perr);
	}

	bool COSE_Signer_map_put_int(HCOSE_SIGNER h, int key, cn_cbor * value, int flags, cose_errback * perr)
	{
	bool fRet = false;

	CHECK_CONDITION(IsValidSignerHandle(h), COSE_ERR_INVALID_HANDLE);
	CHECK_CONDITION(value != NULL, COSE_ERR_INVALID_PARAMETER);

	return _COSE_map_put(&((COSE_SignerInfo *)h)->m_message, key, value, flags, perr);

	errorReturn:
	return fRet;
	}

	#endif