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 "cose_crypto.h"

 #if INCLUDE_SIGN || INCLUDE_COUNTERSIGNATURE

 #if INCLUDE_SIGN
 COSE *SignerRoot = NULL;

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

 bool _COSE_SignerInfo_Release(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);
 	CN_CBOR_FREE(pSigner->m_pkey, &pSigner->m_message.m_allocContext);

 	return true;
 }

 #if INCLUDE_SIGN
 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_Release(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_Release(pobj);
 		COSE_FREE(pobj, context);
 		return NULL;
 	}

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

 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;
 	}

 #if INCLUDE_SIGN
 	if (pIn == NULL) {
 		_COSE_InsertInList(&SignerRoot, &pSigner->m_message);
 	}
 #endif
 	return pSigner;

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

 static 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,
 	const char *const contextString,
 	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(
 		contextString, 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);
 	const ssize_t writtenBits =
 		cn_cbor_encoder_write(pbToSign, 0, cbToSign, pArray);
 	CHECK_CONDITION(writtenBits >= 0, COSE_ERR_CBOR);
 	CHECK_CONDITION((size_t)writtenBits == 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,
 	const char *const contextString,
 	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, contextString,
 			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);
 	}

 #if INCLUDE_COUNTERSIGNATURE
 	if (pSigner->m_message.m_counterSigners != NULL) {
 		if (!_COSE_CounterSign_Sign(
 				&pSigner->m_message, CBOR_CONTEXT_PARAM_COMMA perr)) {
 			goto errorReturn;
 		}
 	}
 #endif

 	fRet = true;

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

 #if INCLUDE_SIGN
 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);
 }
 #endif

 bool _COSE_Signer_validate(COSE_SignerInfo *pSigner,
 	const cn_cbor *pcborBody,
 	const cn_cbor *pcborProtected,
 	const char *const contextString,
 	cose_errback *perr)
 {
 	byte *pbToBeSigned = NULL;
 	int alg = 0;
 #ifdef USE_CBOR_CONTEXT
 	cn_cbor_context *context = &pSigner->m_message.m_allocContext;
 #endif
 	size_t cbToBeSigned;
 	bool fRet = false;

 	const cn_cbor *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, contextString,
 			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;
 }

 #if INCLUDE_SIGN
 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)
 {
 	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 false;
 }
 #endif
 #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 "cose_crypto.h"

	#if INCLUDE_SIGN \|\| INCLUDE_COUNTERSIGNATURE

	#if INCLUDE_SIGN
	COSE *SignerRoot = NULL;

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

	bool _COSE_SignerInfo_Release(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);
	CN_CBOR_FREE(pSigner->m_pkey, &pSigner->m_message.m_allocContext);

	return true;
	}

	#if INCLUDE_SIGN
	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_Release(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_Release(pobj);
	COSE_FREE(pobj, context);
	return NULL;
	}

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

	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;
	}

	#if INCLUDE_SIGN
	if (pIn == NULL) {
	_COSE_InsertInList(&SignerRoot, &pSigner->m_message);
	}
	#endif
	return pSigner;

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

	static 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,
	const char *const contextString,
	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(
	contextString, 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);
	const ssize_t writtenBits =
	cn_cbor_encoder_write(pbToSign, 0, cbToSign, pArray);
	CHECK_CONDITION(writtenBits >= 0, COSE_ERR_CBOR);
	CHECK_CONDITION((size_t)writtenBits == 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,
	const char *const contextString,
	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, contextString,
	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);
	}

	#if INCLUDE_COUNTERSIGNATURE
	if (pSigner->m_message.m_counterSigners != NULL) {
	if (!_COSE_CounterSign_Sign(
	&pSigner->m_message, CBOR_CONTEXT_PARAM_COMMA perr)) {
	goto errorReturn;
	}
	}
	#endif

	fRet = true;

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

	#if INCLUDE_SIGN
	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);
	}
	#endif

	bool _COSE_Signer_validate(COSE_SignerInfo *pSigner,
	const cn_cbor *pcborBody,
	const cn_cbor *pcborProtected,
	const char *const contextString,
	cose_errback *perr)
	{
	byte *pbToBeSigned = NULL;
	int alg = 0;
	#ifdef USE_CBOR_CONTEXT
	cn_cbor_context *context = &pSigner->m_message.m_allocContext;
	#endif
	size_t cbToBeSigned;
	bool fRet = false;

	const cn_cbor *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, contextString,
	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;
	}

	#if INCLUDE_SIGN
	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)
	{
	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 false;
	}
	#endif
	#endif