/*
 * Copyright (c)2019 ZeroTier, Inc.
 *
 * Use of this software is governed by the Business Source License included
 * in the LICENSE.TXT file in the project's root directory.
 *
 * Change Date: 2023-01-01
 *
 * On the date above, in accordance with the Business Source License, use
 * of this software will be governed by version 2.0 of the Apache License.
 */
/****/

#ifndef ZT_SHA512_HPP
#define ZT_SHA512_HPP

#include "Constants.hpp"

#ifdef __APPLE__
#include <CommonCrypto/CommonDigest.h>
#endif

#ifdef ZT_USE_LIBCRYPTO
#include <openssl/sha.h>
#endif

#define ZT_SHA512_DIGEST_LEN 64
#define ZT_SHA384_DIGEST_LEN 48

#define ZT_SHA512_BLOCK_SIZE 128
#define ZT_SHA384_BLOCK_SIZE 128

#define ZT_HMACSHA384_LEN 48

namespace ZeroTier {

#ifdef __APPLE__
#define ZT_HAVE_NATIVE_SHA512 1
static inline void SHA512(void *digest,const void *data,unsigned int len)
{
	CC_SHA512_CTX ctx;
	CC_SHA512_Init(&ctx);
	CC_SHA512_Update(&ctx,data,len);
	CC_SHA512_Final(reinterpret_cast<unsigned char *>(digest),&ctx);
}
static inline void SHA384(void *digest,const void *data,unsigned int len)
{
	CC_SHA512_CTX ctx;
	CC_SHA384_Init(&ctx);
	CC_SHA384_Update(&ctx,data,len);
	CC_SHA384_Final(reinterpret_cast<unsigned char *>(digest),&ctx);
}
static inline void SHA384(void *digest,const void *data0,unsigned int len0,const void *data1,unsigned int len1)
{
	CC_SHA512_CTX ctx;
	CC_SHA384_Init(&ctx);
	CC_SHA384_Update(&ctx,data0,len0);
	CC_SHA384_Update(&ctx,data1,len1);
	CC_SHA384_Final(reinterpret_cast<unsigned char *>(digest),&ctx);
}
#endif

#ifdef ZT_USE_LIBCRYPTO
#define ZT_HAVE_NATIVE_SHA512 1
static inline void SHA512(void *digest,const void *data,unsigned int len)
{
	SHA512_CTX ctx;
	SHA512_Init(&ctx);
	SHA512_Update(&ctx,data,len);
	SHA512_Final(reinterpret_cast<unsigned char *>(digest),&ctx);
}
static inline void SHA384(void *digest,const void *data,unsigned int len)
{
	SHA512_CTX ctx;
	SHA384_Init(&ctx);
	SHA384_Update(&ctx,data,len);
	SHA384_Final(reinterpret_cast<unsigned char *>(digest),&ctx);
}
static inline void SHA384(void *digest,const void *data0,unsigned int len0,const void *data1,unsigned int len1)
{
	SHA512_CTX ctx;
	SHA384_Init(&ctx);
	SHA384_Update(&ctx,data0,len0);
	SHA384_Update(&ctx,data1,len1);
	SHA384_Final(reinterpret_cast<unsigned char *>(digest),&ctx);
}
#endif

#ifndef ZT_HAVE_NATIVE_SHA512
void SHA512(void *digest,const void *data,unsigned int len);
void SHA384(void *digest,const void *data,unsigned int len);
void SHA384(void *digest,const void *data0,unsigned int len0,const void *data1,unsigned int len1);
#endif

static inline void HMACSHA384(const uint8_t key[32],const void *msg,const unsigned int msglen,uint8_t mac[48])
{
	uint64_t kInPadded[16];
	uint64_t outer[22]; // output padded key | H(input padded key | msg)

#ifdef ZT_NO_TYPE_PUNNING
	for(int i=0;i<32;++i) ((uint8_t *)kInPadded)[i] = key[i] ^ 0x36;
	for(int i=4;i<16;++i) kInPadded[i] = 0x3636363636363636ULL;
	for(int i=0;i<32;++i) ((uint8_t *)outer)[i] = key[i] ^ 0x5c;
	for(int i=4;i<16;++i) outer[i] = 0x5c5c5c5c5c5c5c5cULL;
#else
	{
		const uint64_t k0 = ((const uint64_t *)key)[0];
		const uint64_t k1 = ((const uint64_t *)key)[1];
		const uint64_t k2 = ((const uint64_t *)key)[2];
		const uint64_t k3 = ((const uint64_t *)key)[3];
		kInPadded[0] = k0 ^ 0x3636363636363636ULL;
		kInPadded[0] = k1 ^ 0x3636363636363636ULL;
		kInPadded[0] = k2 ^ 0x3636363636363636ULL;
		kInPadded[0] = k3 ^ 0x3636363636363636ULL;
		for(int i=4;i<16;++i) kInPadded[i] = 0x3636363636363636ULL;
		outer[0] = k0 ^ 0x5c5c5c5c5c5c5c5cULL;
		outer[1] = k1 ^ 0x5c5c5c5c5c5c5c5cULL;
		outer[2] = k2 ^ 0x5c5c5c5c5c5c5c5cULL;
		outer[3] = k3 ^ 0x5c5c5c5c5c5c5c5cULL;
		for(int i=4;i<16;++i) outer[i] = 0x5c5c5c5c5c5c5c5cULL;
	}
#endif

	SHA384(((uint8_t *)outer) + 128,kInPadded,128,msg,msglen); // H(input padded key | msg)
	SHA384(mac,outer,176); // H(output padded key | H(input padded key | msg))
}

} // namespace ZeroTier

#endif