/*	$NetBSD: pkcs11eddsa_link.c,v 1.1.2.2 2024/02/24 13:07:00 martin Exp $	*/

/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0.  If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#if USE_PKCS11

#include <stdbool.h>

#include <isc/mem.h>
#include <isc/safe.h>
#include <isc/string.h>
#include <isc/util.h>

#include <pk11/constants.h>
#include <pk11/internal.h>
#include <pk11/pk11.h>
#include <pkcs11/pkcs11.h>

#include <dns/keyvalues.h>

#include <dst/result.h>

#include "dst_internal.h"
#include "dst_parse.h"
#include "dst_pkcs11.h"

/*
 * FIPS 186-3 EDDSA keys:
 *  mechanisms:
 *    CKM_EDDSA,
 *    CKM_EC_EDWARDS_KEY_PAIR_GEN
 *  domain parameters:
 *    CKA_EC_PARAMS (choice with OID namedCurve)
 *  public keys:
 *    object class CKO_PUBLIC_KEY
 *    key type CKK_EC_EDWARDS
 *    attribute CKA_EC_PARAMS (choice with OID namedCurve)
 *    attribute CKA_EC_POINT (big int A)
 *  private keys:
 *    object class CKO_PRIVATE_KEY
 *    key type CKK_EC_EDWARDS
 *    attribute CKA_EC_PARAMS (choice with OID namedCurve)
 *    attribute CKA_VALUE (big int k)
 *  point format: 0x04 (octet-string) <size> <A>
 */

#define TAG_OCTECT_STRING 0x04

#define DST_RET(a)        \
	{                 \
		ret = a;  \
		goto err; \
	}

static CK_BBOOL truevalue = TRUE;
static CK_BBOOL falsevalue = FALSE;

static void
pkcs11eddsa_destroy(dst_key_t *key);

static isc_result_t
pkcs11eddsa_createctx(dst_key_t *key, dst_context_t *dctx) {
	isc_buffer_t *buf = NULL;

	UNUSED(key);
	REQUIRE(dctx->key->key_alg == DST_ALG_ED25519 ||
		dctx->key->key_alg == DST_ALG_ED448);

	isc_buffer_allocate(dctx->mctx, &buf, 16);
	isc_buffer_setautorealloc(buf, true);
	dctx->ctxdata.generic = buf;

	return (ISC_R_SUCCESS);
}

static void
pkcs11eddsa_destroyctx(dst_context_t *dctx) {
	isc_buffer_t *buf = (isc_buffer_t *)dctx->ctxdata.generic;

	REQUIRE(dctx->key->key_alg == DST_ALG_ED25519 ||
		dctx->key->key_alg == DST_ALG_ED448);
	if (buf != NULL) {
		isc_buffer_free(&buf);
	}
	dctx->ctxdata.generic = NULL;
}

static isc_result_t
pkcs11eddsa_adddata(dst_context_t *dctx, const isc_region_t *data) {
	isc_buffer_t *buf = (isc_buffer_t *)dctx->ctxdata.generic;
	isc_result_t result;

	REQUIRE(dctx->key->key_alg == DST_ALG_ED25519 ||
		dctx->key->key_alg == DST_ALG_ED448);

	result = isc_buffer_copyregion(buf, data);
	INSIST(result == ISC_R_SUCCESS);

	return (result);
}

static isc_result_t
pkcs11eddsa_sign(dst_context_t *dctx, isc_buffer_t *sig) {
	isc_buffer_t *buf = (isc_buffer_t *)dctx->ctxdata.generic;
	CK_RV rv;
	CK_MECHANISM mech = { CKM_EDDSA, NULL, 0 };
	CK_OBJECT_HANDLE hKey = CK_INVALID_HANDLE;
	CK_OBJECT_CLASS keyClass = CKO_PRIVATE_KEY;
	CK_KEY_TYPE keyType = CKK_EC_EDWARDS;
	CK_ATTRIBUTE keyTemplate[] = {
		{ CKA_CLASS, &keyClass, (CK_ULONG)sizeof(keyClass) },
		{ CKA_KEY_TYPE, &keyType, (CK_ULONG)sizeof(keyType) },
		{ CKA_TOKEN, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_PRIVATE, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_SIGN, &truevalue, (CK_ULONG)sizeof(truevalue) },
		{ CKA_EC_PARAMS, NULL, 0 },
		{ CKA_VALUE, NULL, 0 }
	};
	CK_ATTRIBUTE *attr;
	CK_ULONG siglen;
	CK_SLOT_ID slotid;
	pk11_context_t *pk11_ctx;
	dst_key_t *key = dctx->key;
	pk11_object_t *ec = key->keydata.pkey;
	isc_region_t t;
	isc_region_t r;
	isc_result_t ret = ISC_R_SUCCESS;
	unsigned int i;

	REQUIRE(key->key_alg == DST_ALG_ED25519 ||
		key->key_alg == DST_ALG_ED448);
	REQUIRE(ec != NULL);

	switch (key->key_alg) {
	case DST_ALG_ED25519:
		siglen = DNS_SIG_ED25519SIZE;
		break;
	case DST_ALG_ED448:
		siglen = DNS_SIG_ED448SIZE;
		break;
	default:
		UNREACHABLE();
	}

	pk11_ctx = isc_mem_get(dctx->mctx, sizeof(*pk11_ctx));
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	if (ec->ontoken && (dctx->use == DO_SIGN)) {
		slotid = ec->slot;
	} else {
		slotid = pk11_get_best_token(OP_EDDSA);
	}
	ret = pk11_get_session(pk11_ctx, OP_EDDSA, true, false, ec->reqlogon,
			       NULL, slotid);
	if (ret != ISC_R_SUCCESS) {
		goto err;
	}

	isc_buffer_availableregion(sig, &r);
	if (r.length < siglen) {
		DST_RET(ISC_R_NOSPACE);
	}

	if (ec->ontoken && (ec->object != CK_INVALID_HANDLE)) {
		pk11_ctx->ontoken = ec->ontoken;
		pk11_ctx->object = ec->object;
		goto token_key;
	}

	for (attr = pk11_attribute_first(ec); attr != NULL;
	     attr = pk11_attribute_next(ec, attr))
	{
		switch (attr->type) {
		case CKA_EC_PARAMS:
			INSIST(keyTemplate[5].type == attr->type);
			keyTemplate[5].pValue = isc_mem_get(dctx->mctx,
							    attr->ulValueLen);
			memmove(keyTemplate[5].pValue, attr->pValue,
				attr->ulValueLen);
			keyTemplate[5].ulValueLen = attr->ulValueLen;
			break;
		case CKA_VALUE:
			INSIST(keyTemplate[6].type == attr->type);
			keyTemplate[6].pValue = isc_mem_get(dctx->mctx,
							    attr->ulValueLen);
			memmove(keyTemplate[6].pValue, attr->pValue,
				attr->ulValueLen);
			keyTemplate[6].ulValueLen = attr->ulValueLen;
			break;
		}
	}
	pk11_ctx->object = CK_INVALID_HANDLE;
	pk11_ctx->ontoken = false;
	PK11_RET(pkcs_C_CreateObject,
		 (pk11_ctx->session, keyTemplate, (CK_ULONG)7, &hKey),
		 ISC_R_FAILURE);

token_key:

	PK11_RET(pkcs_C_SignInit,
		 (pk11_ctx->session, &mech,
		  pk11_ctx->ontoken ? pk11_ctx->object : hKey),
		 ISC_R_FAILURE);

	isc_buffer_usedregion(buf, &t);

	PK11_RET(pkcs_C_Sign,
		 (pk11_ctx->session, (CK_BYTE_PTR)t.base, (CK_ULONG)t.length,
		  (CK_BYTE_PTR)r.base, &siglen),
		 DST_R_SIGNFAILURE);

	isc_buffer_add(sig, (unsigned int)siglen);

err:

	if (hKey != CK_INVALID_HANDLE) {
		(void)pkcs_C_DestroyObject(pk11_ctx->session, hKey);
	}
	for (i = 5; i <= 6; i++) {
		if (keyTemplate[i].pValue != NULL) {
			{
				memset(keyTemplate[i].pValue, 0,
				       keyTemplate[i].ulValueLen);
				isc_mem_put(dctx->mctx, keyTemplate[i].pValue,
					    keyTemplate[i].ulValueLen);
			}
		}
	}
	pk11_return_session(pk11_ctx);
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	isc_mem_put(dctx->mctx, pk11_ctx, sizeof(*pk11_ctx));
	isc_buffer_free(&buf);
	dctx->ctxdata.generic = NULL;

	return (ret);
}

static isc_result_t
pkcs11eddsa_verify(dst_context_t *dctx, const isc_region_t *sig) {
	isc_buffer_t *buf = (isc_buffer_t *)dctx->ctxdata.generic;
	CK_RV rv;
	CK_MECHANISM mech = { CKM_EDDSA, NULL, 0 };
	CK_OBJECT_HANDLE hKey = CK_INVALID_HANDLE;
	CK_OBJECT_CLASS keyClass = CKO_PUBLIC_KEY;
	CK_KEY_TYPE keyType = CKK_EC_EDWARDS;
	CK_ATTRIBUTE keyTemplate[] = {
		{ CKA_CLASS, &keyClass, (CK_ULONG)sizeof(keyClass) },
		{ CKA_KEY_TYPE, &keyType, (CK_ULONG)sizeof(keyType) },
		{ CKA_TOKEN, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_PRIVATE, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_VERIFY, &truevalue, (CK_ULONG)sizeof(truevalue) },
		{ CKA_EC_PARAMS, NULL, 0 },
		{ CKA_EC_POINT, NULL, 0 }
	};
	CK_ATTRIBUTE *attr;
	CK_SLOT_ID slotid;
	pk11_context_t *pk11_ctx;
	dst_key_t *key = dctx->key;
	pk11_object_t *ec = key->keydata.pkey;
	isc_region_t t;
	isc_result_t ret = ISC_R_SUCCESS;
	unsigned int i;

	REQUIRE(key->key_alg == DST_ALG_ED25519 ||
		key->key_alg == DST_ALG_ED448);
	REQUIRE(ec != NULL);

	pk11_ctx = isc_mem_get(dctx->mctx, sizeof(*pk11_ctx));
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	if (ec->ontoken && (dctx->use == DO_SIGN)) {
		slotid = ec->slot;
	} else {
		slotid = pk11_get_best_token(OP_EDDSA);
	}
	ret = pk11_get_session(pk11_ctx, OP_EDDSA, true, false, ec->reqlogon,
			       NULL, slotid);
	if (ret != ISC_R_SUCCESS) {
		goto err;
	}

	for (attr = pk11_attribute_first(ec); attr != NULL;
	     attr = pk11_attribute_next(ec, attr))
	{
		switch (attr->type) {
		case CKA_EC_PARAMS:
			INSIST(keyTemplate[5].type == attr->type);
			keyTemplate[5].pValue = isc_mem_get(dctx->mctx,
							    attr->ulValueLen);
			memmove(keyTemplate[5].pValue, attr->pValue,
				attr->ulValueLen);
			keyTemplate[5].ulValueLen = attr->ulValueLen;
			break;
		case CKA_EC_POINT:
			INSIST(keyTemplate[6].type == attr->type);
			keyTemplate[6].pValue = isc_mem_get(dctx->mctx,
							    attr->ulValueLen);
			memmove(keyTemplate[6].pValue, attr->pValue,
				attr->ulValueLen);
			keyTemplate[6].ulValueLen = attr->ulValueLen;
			break;
		}
	}
	pk11_ctx->object = CK_INVALID_HANDLE;
	pk11_ctx->ontoken = false;
	PK11_RET(pkcs_C_CreateObject,
		 (pk11_ctx->session, keyTemplate, (CK_ULONG)7, &hKey),
		 ISC_R_FAILURE);

	PK11_RET(pkcs_C_VerifyInit, (pk11_ctx->session, &mech, hKey),
		 ISC_R_FAILURE);

	isc_buffer_usedregion(buf, &t);

	PK11_RET(pkcs_C_Verify,
		 (pk11_ctx->session, (CK_BYTE_PTR)t.base, (CK_ULONG)t.length,
		  (CK_BYTE_PTR)sig->base, (CK_ULONG)sig->length),
		 DST_R_VERIFYFAILURE);

err:

	if (hKey != CK_INVALID_HANDLE) {
		(void)pkcs_C_DestroyObject(pk11_ctx->session, hKey);
	}
	for (i = 5; i <= 6; i++) {
		if (keyTemplate[i].pValue != NULL) {
			{
				memset(keyTemplate[i].pValue, 0,
				       keyTemplate[i].ulValueLen);
				isc_mem_put(dctx->mctx, keyTemplate[i].pValue,
					    keyTemplate[i].ulValueLen);
			}
		}
	}
	pk11_return_session(pk11_ctx);
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	isc_mem_put(dctx->mctx, pk11_ctx, sizeof(*pk11_ctx));
	isc_buffer_free(&buf);
	dctx->ctxdata.generic = NULL;

	return (ret);
}

static bool
pkcs11eddsa_compare(const dst_key_t *key1, const dst_key_t *key2) {
	pk11_object_t *ec1, *ec2;
	CK_ATTRIBUTE *attr1, *attr2;

	ec1 = key1->keydata.pkey;
	ec2 = key2->keydata.pkey;

	if ((ec1 == NULL) && (ec2 == NULL)) {
		return (true);
	} else if ((ec1 == NULL) || (ec2 == NULL)) {
		return (false);
	}

	attr1 = pk11_attribute_bytype(ec1, CKA_EC_PARAMS);
	attr2 = pk11_attribute_bytype(ec2, CKA_EC_PARAMS);
	if ((attr1 == NULL) && (attr2 == NULL)) {
		return (true);
	} else if ((attr1 == NULL) || (attr2 == NULL) ||
		   (attr1->ulValueLen != attr2->ulValueLen) ||
		   !isc_safe_memequal(attr1->pValue, attr2->pValue,
				      attr1->ulValueLen))
	{
		return (false);
	}

	attr1 = pk11_attribute_bytype(ec1, CKA_EC_POINT);
	attr2 = pk11_attribute_bytype(ec2, CKA_EC_POINT);
	if ((attr1 == NULL) && (attr2 == NULL)) {
		return (true);
	} else if ((attr1 == NULL) || (attr2 == NULL) ||
		   (attr1->ulValueLen != attr2->ulValueLen) ||
		   !isc_safe_memequal(attr1->pValue, attr2->pValue,
				      attr1->ulValueLen))
	{
		return (false);
	}

	attr1 = pk11_attribute_bytype(ec1, CKA_VALUE);
	attr2 = pk11_attribute_bytype(ec2, CKA_VALUE);
	if (((attr1 != NULL) || (attr2 != NULL)) &&
	    ((attr1 == NULL) || (attr2 == NULL) ||
	     (attr1->ulValueLen != attr2->ulValueLen) ||
	     !isc_safe_memequal(attr1->pValue, attr2->pValue,
				attr1->ulValueLen)))
	{
		return (false);
	}

	if (!ec1->ontoken && !ec2->ontoken) {
		return (true);
	} else if (ec1->ontoken || ec2->ontoken || (ec1->object != ec2->object))
	{
		return (false);
	}

	return (true);
}

#define SETCURVE()                                                             \
	switch (key->key_alg) {                                                \
	case DST_ALG_ED25519:                                                  \
		attr->pValue = isc_mem_get(key->mctx,                          \
					   sizeof(PK11_ECX_ED25519));          \
		memmove(attr->pValue, PK11_ECX_ED25519,                        \
			sizeof(PK11_ECX_ED25519));                             \
		attr->ulValueLen = sizeof(PK11_ECX_ED25519);                   \
		break;                                                         \
	case DST_ALG_ED448:                                                    \
		attr->pValue = isc_mem_get(key->mctx, sizeof(PK11_ECX_ED448)); \
		memmove(attr->pValue, PK11_ECX_ED448, sizeof(PK11_ECX_ED448)); \
		attr->ulValueLen = sizeof(PK11_ECX_ED448);                     \
		break;                                                         \
	default:                                                               \
		UNREACHABLE();                                                 \
	}

#define FREECURVE()                                                     \
	if (attr->pValue != NULL) {                                     \
		memset(attr->pValue, 0, attr->ulValueLen);              \
		isc_mem_put(key->mctx, attr->pValue, attr->ulValueLen); \
		attr->pValue = NULL;                                    \
	}

static isc_result_t
pkcs11eddsa_generate(dst_key_t *key, int unused, void (*callback)(int)) {
	CK_RV rv;
	CK_MECHANISM mech = { CKM_EC_EDWARDS_KEY_PAIR_GEN, NULL, 0 };
	CK_OBJECT_HANDLE pub = CK_INVALID_HANDLE;
	CK_OBJECT_CLASS pubClass = CKO_PUBLIC_KEY;
	CK_KEY_TYPE keyType = CKK_EC_EDWARDS;
	CK_ATTRIBUTE pubTemplate[] = {
		{ CKA_CLASS, &pubClass, (CK_ULONG)sizeof(pubClass) },
		{ CKA_KEY_TYPE, &keyType, (CK_ULONG)sizeof(keyType) },
		{ CKA_TOKEN, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_PRIVATE, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_VERIFY, &truevalue, (CK_ULONG)sizeof(truevalue) },
		{ CKA_EC_PARAMS, NULL, 0 }
	};
	CK_OBJECT_HANDLE priv = CK_INVALID_HANDLE;
	CK_OBJECT_HANDLE privClass = CKO_PRIVATE_KEY;
	CK_ATTRIBUTE privTemplate[] = {
		{ CKA_CLASS, &privClass, (CK_ULONG)sizeof(privClass) },
		{ CKA_KEY_TYPE, &keyType, (CK_ULONG)sizeof(keyType) },
		{ CKA_TOKEN, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_PRIVATE, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_SENSITIVE, &falsevalue, (CK_ULONG)sizeof(falsevalue) },
		{ CKA_EXTRACTABLE, &truevalue, (CK_ULONG)sizeof(truevalue) },
		{ CKA_SIGN, &truevalue, (CK_ULONG)sizeof(truevalue) }
	};
	CK_ATTRIBUTE *attr;
	pk11_object_t *ec;
	pk11_context_t *pk11_ctx;
	isc_result_t ret;

	REQUIRE(key->key_alg == DST_ALG_ED25519 ||
		key->key_alg == DST_ALG_ED448);
	UNUSED(unused);
	UNUSED(callback);

	pk11_ctx = isc_mem_get(key->mctx, sizeof(*pk11_ctx));
	ret = pk11_get_session(pk11_ctx, OP_EDDSA, true, false, false, NULL,
			       pk11_get_best_token(OP_EDDSA));
	if (ret != ISC_R_SUCCESS) {
		goto err;
	}

	ec = isc_mem_get(key->mctx, sizeof(*ec));
	memset(ec, 0, sizeof(*ec));
	key->keydata.pkey = ec;
	ec->repr = isc_mem_get(key->mctx, sizeof(*attr) * 3);
	memset(ec->repr, 0, sizeof(*attr) * 3);
	ec->attrcnt = 3;

	attr = ec->repr;
	attr[0].type = CKA_EC_PARAMS;
	attr[1].type = CKA_EC_POINT;
	attr[2].type = CKA_VALUE;

	attr = &pubTemplate[5];
	SETCURVE();

	PK11_RET(pkcs_C_GenerateKeyPair,
		 (pk11_ctx->session, &mech, pubTemplate, (CK_ULONG)6,
		  privTemplate, (CK_ULONG)7, &pub, &priv),
		 DST_R_CRYPTOFAILURE);

	attr = &pubTemplate[5];
	FREECURVE();

	attr = ec->repr;
	SETCURVE();

	attr++;
	PK11_RET(pkcs_C_GetAttributeValue, (pk11_ctx->session, pub, attr, 1),
		 DST_R_CRYPTOFAILURE);
	attr->pValue = isc_mem_get(key->mctx, attr->ulValueLen);
	memset(attr->pValue, 0, attr->ulValueLen);
	PK11_RET(pkcs_C_GetAttributeValue, (pk11_ctx->session, pub, attr, 1),
		 DST_R_CRYPTOFAILURE);

	attr++;
	PK11_RET(pkcs_C_GetAttributeValue, (pk11_ctx->session, priv, attr, 1),
		 DST_R_CRYPTOFAILURE);
	attr->pValue = isc_mem_get(key->mctx, attr->ulValueLen);
	memset(attr->pValue, 0, attr->ulValueLen);
	PK11_RET(pkcs_C_GetAttributeValue, (pk11_ctx->session, priv, attr, 1),
		 DST_R_CRYPTOFAILURE);

	(void)pkcs_C_DestroyObject(pk11_ctx->session, priv);
	(void)pkcs_C_DestroyObject(pk11_ctx->session, pub);
	pk11_return_session(pk11_ctx);
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	isc_mem_put(key->mctx, pk11_ctx, sizeof(*pk11_ctx));

	switch (key->key_alg) {
	case DST_ALG_ED25519:
		key->key_size = DNS_KEY_ED25519SIZE * 8;
		break;
	case DST_ALG_ED448:
		key->key_size = DNS_KEY_ED448SIZE * 8;
		break;
	default:
		UNREACHABLE();
	}

	return (ISC_R_SUCCESS);

err:
	pkcs11eddsa_destroy(key);
	if (priv != CK_INVALID_HANDLE) {
		(void)pkcs_C_DestroyObject(pk11_ctx->session, priv);
	}
	if (pub != CK_INVALID_HANDLE) {
		(void)pkcs_C_DestroyObject(pk11_ctx->session, pub);
	}
	pk11_return_session(pk11_ctx);
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	isc_mem_put(key->mctx, pk11_ctx, sizeof(*pk11_ctx));

	return (ret);
}

static bool
pkcs11eddsa_isprivate(const dst_key_t *key) {
	pk11_object_t *ec = key->keydata.pkey;
	CK_ATTRIBUTE *attr;

	if (ec == NULL) {
		return (false);
	}
	attr = pk11_attribute_bytype(ec, CKA_VALUE);
	return (attr != NULL || ec->ontoken);
}

static void
pkcs11eddsa_destroy(dst_key_t *key) {
	pk11_object_t *ec = key->keydata.pkey;
	CK_ATTRIBUTE *attr;

	if (ec == NULL) {
		return;
	}

	INSIST((ec->object == CK_INVALID_HANDLE) || ec->ontoken);

	for (attr = pk11_attribute_first(ec); attr != NULL;
	     attr = pk11_attribute_next(ec, attr))
	{
		switch (attr->type) {
		case CKA_LABEL:
		case CKA_ID:
		case CKA_EC_PARAMS:
		case CKA_EC_POINT:
		case CKA_VALUE:
			FREECURVE();
			break;
		}
	}
	if (ec->repr != NULL) {
		memset(ec->repr, 0, ec->attrcnt * sizeof(*attr));
		isc_mem_put(key->mctx, ec->repr, ec->attrcnt * sizeof(*attr));
	}
	memset(ec, 0, sizeof(*ec));
	isc_mem_put(key->mctx, ec, sizeof(*ec));
	key->keydata.pkey = NULL;
}

static isc_result_t
pkcs11eddsa_todns(const dst_key_t *key, isc_buffer_t *data) {
	pk11_object_t *ec;
	isc_region_t r;
	unsigned int len;
	CK_ATTRIBUTE *attr;

	REQUIRE(key->keydata.pkey != NULL);

	switch (key->key_alg) {
	case DST_ALG_ED25519:
		len = DNS_KEY_ED25519SIZE;
		break;
	case DST_ALG_ED448:
		len = DNS_KEY_ED448SIZE;
		break;
	default:
		UNREACHABLE();
	}

	ec = key->keydata.pkey;
	attr = pk11_attribute_bytype(ec, CKA_EC_POINT);
	if ((attr == NULL) || (attr->ulValueLen != len + 2) ||
	    (((CK_BYTE_PTR)attr->pValue)[0] != TAG_OCTECT_STRING) ||
	    (((CK_BYTE_PTR)attr->pValue)[1] != len))
	{
		return (ISC_R_FAILURE);
	}

	isc_buffer_availableregion(data, &r);
	if (r.length < len) {
		return (ISC_R_NOSPACE);
	}
	memmove(r.base, (CK_BYTE_PTR)attr->pValue + 2, len);
	isc_buffer_add(data, len);

	return (ISC_R_SUCCESS);
}

static isc_result_t
pkcs11eddsa_fromdns(dst_key_t *key, isc_buffer_t *data) {
	pk11_object_t *ec;
	isc_region_t r;
	unsigned int len;
	CK_ATTRIBUTE *attr;

	REQUIRE(key->key_alg == DST_ALG_ED25519 ||
		key->key_alg == DST_ALG_ED448);

	switch (key->key_alg) {
	case DST_ALG_ED25519:
		len = DNS_KEY_ED25519SIZE;
		break;
	case DST_ALG_ED448:
		len = DNS_KEY_ED448SIZE;
		break;
	default:
		UNREACHABLE();
	}

	isc_buffer_remainingregion(data, &r);
	if (r.length == 0) {
		return (ISC_R_SUCCESS);
	}
	if (r.length != len) {
		return (DST_R_INVALIDPUBLICKEY);
	}

	ec = isc_mem_get(key->mctx, sizeof(*ec));
	memset(ec, 0, sizeof(*ec));
	ec->repr = isc_mem_get(key->mctx, sizeof(*attr) * 2);
	ec->attrcnt = 2;

	attr = ec->repr;
	attr->type = CKA_EC_PARAMS;
	SETCURVE();

	attr++;
	attr->type = CKA_EC_POINT;
	attr->pValue = isc_mem_get(key->mctx, len + 2);
	((CK_BYTE_PTR)attr->pValue)[0] = TAG_OCTECT_STRING;
	((CK_BYTE_PTR)attr->pValue)[1] = len;
	memmove((CK_BYTE_PTR)attr->pValue + 2, r.base, len);
	attr->ulValueLen = len + 2;

	isc_buffer_forward(data, len);
	key->keydata.pkey = ec;
	key->key_size = len * 8;

	return (ISC_R_SUCCESS);
}

static isc_result_t
pkcs11eddsa_tofile(const dst_key_t *key, const char *directory) {
	isc_result_t ret;
	pk11_object_t *ec;
	dst_private_t priv;
	unsigned char *buf = NULL;
	unsigned int i = 0;
	CK_ATTRIBUTE *attr;

	if (key->keydata.pkey == NULL) {
		return (DST_R_NULLKEY);
	}

	if (key->external) {
		priv.nelements = 0;
		return (dst__privstruct_writefile(key, &priv, directory));
	}

	ec = key->keydata.pkey;
	attr = pk11_attribute_bytype(ec, CKA_VALUE);
	if (attr != NULL) {
		buf = isc_mem_get(key->mctx, attr->ulValueLen);
		priv.elements[i].tag = TAG_EDDSA_PRIVATEKEY;
		priv.elements[i].length = (unsigned short)attr->ulValueLen;
		memmove(buf, attr->pValue, attr->ulValueLen);
		priv.elements[i].data = buf;
		i++;
	}

	if (key->engine != NULL) {
		priv.elements[i].tag = TAG_EDDSA_ENGINE;
		priv.elements[i].length = strlen(key->engine) + 1;
		priv.elements[i].data = (unsigned char *)key->engine;
		i++;
	}

	if (key->label != NULL) {
		priv.elements[i].tag = TAG_EDDSA_LABEL;
		priv.elements[i].length = strlen(key->label) + 1;
		priv.elements[i].data = (unsigned char *)key->label;
		i++;
	}

	priv.nelements = i;
	ret = dst__privstruct_writefile(key, &priv, directory);

	if (buf != NULL) {
		memset(buf, 0, attr->ulValueLen);
		isc_mem_put(key->mctx, buf, attr->ulValueLen);
	}
	return (ret);
}

static isc_result_t
pkcs11eddsa_fetch(dst_key_t *key, const char *engine, const char *label,
		  dst_key_t *pub) {
	CK_RV rv;
	CK_OBJECT_CLASS keyClass = CKO_PRIVATE_KEY;
	CK_KEY_TYPE keyType = CKK_EC_EDWARDS;
	CK_ATTRIBUTE searchTemplate[] = {
		{ CKA_CLASS, &keyClass, (CK_ULONG)sizeof(keyClass) },
		{ CKA_KEY_TYPE, &keyType, (CK_ULONG)sizeof(keyType) },
		{ CKA_TOKEN, &truevalue, (CK_ULONG)sizeof(truevalue) },
		{ CKA_LABEL, NULL, 0 }
	};
	CK_ULONG cnt;
	CK_ATTRIBUTE *attr;
	CK_ATTRIBUTE *pubattr;
	pk11_object_t *ec;
	pk11_object_t *pubec;
	pk11_context_t *pk11_ctx = NULL;
	isc_result_t ret;

	if (label == NULL) {
		return (DST_R_NOENGINE);
	}

	ec = key->keydata.pkey;
	pubec = pub->keydata.pkey;

	ec->object = CK_INVALID_HANDLE;
	ec->ontoken = true;
	ec->reqlogon = true;
	ec->repr = isc_mem_get(key->mctx, sizeof(*attr) * 2);
	memset(ec->repr, 0, sizeof(*attr) * 2);
	ec->attrcnt = 2;
	attr = ec->repr;

	attr->type = CKA_EC_PARAMS;
	pubattr = pk11_attribute_bytype(pubec, CKA_EC_PARAMS);
	INSIST(pubattr != NULL);
	attr->pValue = isc_mem_get(key->mctx, pubattr->ulValueLen);
	memmove(attr->pValue, pubattr->pValue, pubattr->ulValueLen);
	attr->ulValueLen = pubattr->ulValueLen;
	attr++;

	attr->type = CKA_EC_POINT;
	pubattr = pk11_attribute_bytype(pubec, CKA_EC_POINT);
	INSIST(pubattr != NULL);
	attr->pValue = isc_mem_get(key->mctx, pubattr->ulValueLen);
	memmove(attr->pValue, pubattr->pValue, pubattr->ulValueLen);
	attr->ulValueLen = pubattr->ulValueLen;

	ret = pk11_parse_uri(ec, label, key->mctx, OP_EDDSA);
	if (ret != ISC_R_SUCCESS) {
		goto err;
	}

	pk11_ctx = isc_mem_get(key->mctx, sizeof(*pk11_ctx));
	ret = pk11_get_session(pk11_ctx, OP_EDDSA, true, false, ec->reqlogon,
			       NULL, ec->slot);
	if (ret != ISC_R_SUCCESS) {
		goto err;
	}

	attr = pk11_attribute_bytype(ec, CKA_LABEL);
	if (attr == NULL) {
		attr = pk11_attribute_bytype(ec, CKA_ID);
		INSIST(attr != NULL);
		searchTemplate[3].type = CKA_ID;
	}
	searchTemplate[3].pValue = attr->pValue;
	searchTemplate[3].ulValueLen = attr->ulValueLen;

	PK11_RET(pkcs_C_FindObjectsInit,
		 (pk11_ctx->session, searchTemplate, (CK_ULONG)4),
		 DST_R_CRYPTOFAILURE);
	PK11_RET(pkcs_C_FindObjects,
		 (pk11_ctx->session, &ec->object, (CK_ULONG)1, &cnt),
		 DST_R_CRYPTOFAILURE);
	(void)pkcs_C_FindObjectsFinal(pk11_ctx->session);
	if (cnt == 0) {
		DST_RET(ISC_R_NOTFOUND);
	}
	if (cnt > 1) {
		DST_RET(ISC_R_EXISTS);
	}

	if (engine != NULL) {
		key->engine = isc_mem_strdup(key->mctx, engine);
	}

	key->label = isc_mem_strdup(key->mctx, label);

	pk11_return_session(pk11_ctx);
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	isc_mem_put(key->mctx, pk11_ctx, sizeof(*pk11_ctx));
	return (ISC_R_SUCCESS);

err:
	if (pk11_ctx != NULL) {
		pk11_return_session(pk11_ctx);
		memset(pk11_ctx, 0, sizeof(*pk11_ctx));
		isc_mem_put(key->mctx, pk11_ctx, sizeof(*pk11_ctx));
	}
	return (ret);
}

static isc_result_t
pkcs11eddsa_parse(dst_key_t *key, isc_lex_t *lexer, dst_key_t *pub) {
	dst_private_t priv;
	isc_result_t ret;
	pk11_object_t *ec = NULL;
	CK_ATTRIBUTE *attr, *pattr;
	isc_mem_t *mctx = key->mctx;
	unsigned int i;
	const char *engine = NULL, *label = NULL;

	REQUIRE(key->key_alg == DST_ALG_ED25519 ||
		key->key_alg == DST_ALG_ED448);

	if ((pub == NULL) || (pub->keydata.pkey == NULL)) {
		DST_RET(DST_R_INVALIDPRIVATEKEY);
	}

	/* read private key file */
	ret = dst__privstruct_parse(key, DST_ALG_ED25519, lexer, mctx, &priv);
	if (ret != ISC_R_SUCCESS) {
		return (ret);
	}

	if (key->external) {
		if (priv.nelements != 0) {
			DST_RET(DST_R_INVALIDPRIVATEKEY);
		}

		key->keydata.pkey = pub->keydata.pkey;
		pub->keydata.pkey = NULL;
		key->key_size = pub->key_size;

		dst__privstruct_free(&priv, mctx);
		memset(&priv, 0, sizeof(priv));

		return (ISC_R_SUCCESS);
	}

	for (i = 0; i < priv.nelements; i++) {
		switch (priv.elements[i].tag) {
		case TAG_EDDSA_ENGINE:
			engine = (char *)priv.elements[i].data;
			break;
		case TAG_EDDSA_LABEL:
			label = (char *)priv.elements[i].data;
			break;
		default:
			break;
		}
	}
	ec = isc_mem_get(key->mctx, sizeof(*ec));
	memset(ec, 0, sizeof(*ec));
	key->keydata.pkey = ec;

	/* Is this key is stored in a HSM? See if we can fetch it. */
	if ((label != NULL) || (engine != NULL)) {
		ret = pkcs11eddsa_fetch(key, engine, label, pub);
		if (ret != ISC_R_SUCCESS) {
			goto err;
		}
		dst__privstruct_free(&priv, mctx);
		memset(&priv, 0, sizeof(priv));
		return (ret);
	}

	ec->repr = isc_mem_get(key->mctx, sizeof(*attr) * 3);
	memset(ec->repr, 0, sizeof(*attr) * 3);
	ec->attrcnt = 3;

	attr = ec->repr;
	attr->type = CKA_EC_PARAMS;
	pattr = pk11_attribute_bytype(pub->keydata.pkey, CKA_EC_PARAMS);
	INSIST(pattr != NULL);
	attr->pValue = isc_mem_get(key->mctx, pattr->ulValueLen);
	memmove(attr->pValue, pattr->pValue, pattr->ulValueLen);
	attr->ulValueLen = pattr->ulValueLen;

	attr++;
	attr->type = CKA_EC_POINT;
	pattr = pk11_attribute_bytype(pub->keydata.pkey, CKA_EC_POINT);
	INSIST(pattr != NULL);
	attr->pValue = isc_mem_get(key->mctx, pattr->ulValueLen);
	memmove(attr->pValue, pattr->pValue, pattr->ulValueLen);
	attr->ulValueLen = pattr->ulValueLen;

	attr++;
	attr->type = CKA_VALUE;
	attr->pValue = isc_mem_get(key->mctx, priv.elements[0].length);
	memmove(attr->pValue, priv.elements[0].data, priv.elements[0].length);
	attr->ulValueLen = priv.elements[0].length;

	dst__privstruct_free(&priv, mctx);
	memset(&priv, 0, sizeof(priv));
	switch (key->key_alg) {
	case DST_ALG_ED25519:
		key->key_size = DNS_KEY_ED25519SIZE * 8;
		break;
	case DST_ALG_ED448:
		key->key_size = DNS_KEY_ED448SIZE * 8;
		break;
	default:
		UNREACHABLE();
	}

	return (ISC_R_SUCCESS);

err:
	pkcs11eddsa_destroy(key);
	dst__privstruct_free(&priv, mctx);
	memset(&priv, 0, sizeof(priv));
	return (ret);
}

static isc_result_t
pkcs11eddsa_fromlabel(dst_key_t *key, const char *engine, const char *label,
		      const char *pin) {
	CK_RV rv;
	CK_OBJECT_HANDLE hKey = CK_INVALID_HANDLE;
	CK_OBJECT_CLASS keyClass = CKO_PUBLIC_KEY;
	CK_KEY_TYPE keyType = CKK_EC_EDWARDS;
	CK_ATTRIBUTE searchTemplate[] = {
		{ CKA_CLASS, &keyClass, (CK_ULONG)sizeof(keyClass) },
		{ CKA_KEY_TYPE, &keyType, (CK_ULONG)sizeof(keyType) },
		{ CKA_TOKEN, &truevalue, (CK_ULONG)sizeof(truevalue) },
		{ CKA_LABEL, NULL, 0 }
	};
	CK_ULONG cnt;
	CK_ATTRIBUTE *attr;
	pk11_object_t *ec;
	pk11_context_t *pk11_ctx = NULL;
	isc_result_t ret;
	unsigned int i;

	UNUSED(pin);

	ec = isc_mem_get(key->mctx, sizeof(*ec));
	memset(ec, 0, sizeof(*ec));
	ec->object = CK_INVALID_HANDLE;
	ec->ontoken = true;
	ec->reqlogon = true;
	key->keydata.pkey = ec;

	ec->repr = isc_mem_get(key->mctx, sizeof(*attr) * 2);
	memset(ec->repr, 0, sizeof(*attr) * 2);
	ec->attrcnt = 2;
	attr = ec->repr;
	attr[0].type = CKA_EC_PARAMS;
	attr[1].type = CKA_EC_POINT;

	ret = pk11_parse_uri(ec, label, key->mctx, OP_EDDSA);
	if (ret != ISC_R_SUCCESS) {
		goto err;
	}

	pk11_ctx = isc_mem_get(key->mctx, sizeof(*pk11_ctx));
	ret = pk11_get_session(pk11_ctx, OP_EDDSA, true, false, ec->reqlogon,
			       NULL, ec->slot);
	if (ret != ISC_R_SUCCESS) {
		goto err;
	}

	attr = pk11_attribute_bytype(ec, CKA_LABEL);
	if (attr == NULL) {
		attr = pk11_attribute_bytype(ec, CKA_ID);
		INSIST(attr != NULL);
		searchTemplate[3].type = CKA_ID;
	}
	searchTemplate[3].pValue = attr->pValue;
	searchTemplate[3].ulValueLen = attr->ulValueLen;

	PK11_RET(pkcs_C_FindObjectsInit,
		 (pk11_ctx->session, searchTemplate, (CK_ULONG)4),
		 DST_R_CRYPTOFAILURE);
	PK11_RET(pkcs_C_FindObjects,
		 (pk11_ctx->session, &hKey, (CK_ULONG)1, &cnt),
		 DST_R_CRYPTOFAILURE);
	(void)pkcs_C_FindObjectsFinal(pk11_ctx->session);
	if (cnt == 0) {
		DST_RET(ISC_R_NOTFOUND);
	}
	if (cnt > 1) {
		DST_RET(ISC_R_EXISTS);
	}

	attr = ec->repr;
	PK11_RET(pkcs_C_GetAttributeValue, (pk11_ctx->session, hKey, attr, 2),
		 DST_R_CRYPTOFAILURE);
	for (i = 0; i <= 1; i++) {
		attr[i].pValue = isc_mem_get(key->mctx, attr[i].ulValueLen);
		memset(attr[i].pValue, 0, attr[i].ulValueLen);
	}
	PK11_RET(pkcs_C_GetAttributeValue, (pk11_ctx->session, hKey, attr, 2),
		 DST_R_CRYPTOFAILURE);

	keyClass = CKO_PRIVATE_KEY;
	PK11_RET(pkcs_C_FindObjectsInit,
		 (pk11_ctx->session, searchTemplate, (CK_ULONG)4),
		 DST_R_CRYPTOFAILURE);
	PK11_RET(pkcs_C_FindObjects,
		 (pk11_ctx->session, &ec->object, (CK_ULONG)1, &cnt),
		 DST_R_CRYPTOFAILURE);
	(void)pkcs_C_FindObjectsFinal(pk11_ctx->session);
	if (cnt == 0) {
		DST_RET(ISC_R_NOTFOUND);
	}
	if (cnt > 1) {
		DST_RET(ISC_R_EXISTS);
	}

	if (engine != NULL) {
		key->engine = isc_mem_strdup(key->mctx, engine);
	}

	key->label = isc_mem_strdup(key->mctx, label);
	switch (key->key_alg) {
	case DST_ALG_ED25519:
		key->key_size = DNS_KEY_ED25519SIZE * 8;
		break;
	case DST_ALG_ED448:
		key->key_size = DNS_KEY_ED448SIZE * 8;
		break;
	default:
		UNREACHABLE();
	}

	pk11_return_session(pk11_ctx);
	memset(pk11_ctx, 0, sizeof(*pk11_ctx));
	isc_mem_put(key->mctx, pk11_ctx, sizeof(*pk11_ctx));
	return (ISC_R_SUCCESS);

err:
	pkcs11eddsa_destroy(key);
	if (pk11_ctx != NULL) {
		pk11_return_session(pk11_ctx);
		memset(pk11_ctx, 0, sizeof(*pk11_ctx));
		isc_mem_put(key->mctx, pk11_ctx, sizeof(*pk11_ctx));
	}
	return (ret);
}

static dst_func_t pkcs11eddsa_functions = {
	pkcs11eddsa_createctx,
	NULL, /*%< createctx2 */
	pkcs11eddsa_destroyctx,
	pkcs11eddsa_adddata,
	pkcs11eddsa_sign,
	pkcs11eddsa_verify,
	NULL, /*%< verify2 */
	NULL, /*%< computesecret */
	pkcs11eddsa_compare,
	NULL, /*%< paramcompare */
	pkcs11eddsa_generate,
	pkcs11eddsa_isprivate,
	pkcs11eddsa_destroy,
	pkcs11eddsa_todns,
	pkcs11eddsa_fromdns,
	pkcs11eddsa_tofile,
	pkcs11eddsa_parse,
	NULL, /*%< cleanup */
	pkcs11eddsa_fromlabel,
	NULL, /*%< dump */
	NULL, /*%< restore */
};

isc_result_t
dst__pkcs11eddsa_init(dst_func_t **funcp) {
	REQUIRE(funcp != NULL);
	if (*funcp == NULL) {
		*funcp = &pkcs11eddsa_functions;
	}
	return (ISC_R_SUCCESS);
}

#endif /* USE_PKCS11 */