/*
Copyright (c) 2019 DERO Foundation. All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.

3. Neither the name of the copyright holder nor the names of its contributors
may be used to endorse or promote products derived from this software without
specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

package randomx

import "fmt"
import "math/bits"
import "encoding/binary"

var tmp_______ = fmt.Sprintf("dd")

var AES_HASH_1R_STATE0 = ARRAY_TO_BIGENDIAN([4]uint32{0xd7983aad, 0xcc82db47, 0x9fa856de, 0x92b52c0d})
var AES_HASH_1R_STATE1 = ARRAY_TO_BIGENDIAN([4]uint32{0xace78057, 0xf59e125a, 0x15c7b798, 0x338d996e})
var AES_HASH_1R_STATE2 = ARRAY_TO_BIGENDIAN([4]uint32{0xe8a07ce4, 0x5079506b, 0xae62c7d0, 0x6a770017})
var AES_HASH_1R_STATE3 = ARRAY_TO_BIGENDIAN([4]uint32{0x7e994948, 0x79a10005, 0x07ad828d, 0x630a240c})

var AES_HASH_1R_XKEY0 = ARRAY_TO_BIGENDIAN([4]uint32{0x06890201, 0x90dc56bf, 0x8b24949f, 0xf6fa8389})
var AES_HASH_1R_XKEY1 = ARRAY_TO_BIGENDIAN([4]uint32{0xed18f99b, 0xee1043c6, 0x51f4e03c, 0x61b263d1})

// used for final hash calculation
func hashAes1Rx4(input []byte, output []byte) {

	var states [4][4]uint32
	for i := range states {
		states[0][i] = AES_HASH_1R_STATE0[i]
		states[1][i] = AES_HASH_1R_STATE1[i]
		states[2][i] = AES_HASH_1R_STATE2[i]
		states[3][i] = AES_HASH_1R_STATE3[i]
	}

	var in [4][4]uint32
	for input_ptr := 0; input_ptr < len(input); input_ptr += 64 {
		for i := 0; i < 63; i += 4 { // load 64 bytes
			in[i/16][(i%16)/4] = binary.LittleEndian.Uint32(input[input_ptr+i:])
		}

		AES_ENC_ROUND(states[0][:], in[0][:])
		AES_DEC_ROUND(states[1][:], in[1][:])
		AES_ENC_ROUND(states[2][:], in[2][:])
		AES_DEC_ROUND(states[3][:], in[3][:])

	}

	AES_ENC_ROUND(states[0][:], AES_HASH_1R_XKEY0[:])
	AES_DEC_ROUND(states[1][:], AES_HASH_1R_XKEY0[:])
	AES_ENC_ROUND(states[2][:], AES_HASH_1R_XKEY0[:])
	AES_DEC_ROUND(states[3][:], AES_HASH_1R_XKEY0[:])

	AES_ENC_ROUND(states[0][:], AES_HASH_1R_XKEY1[:])
	AES_DEC_ROUND(states[1][:], AES_HASH_1R_XKEY1[:])
	AES_ENC_ROUND(states[2][:], AES_HASH_1R_XKEY1[:])
	AES_DEC_ROUND(states[3][:], AES_HASH_1R_XKEY1[:])

	// write back to state
	for i := 0; i < 63; i += 4 {
		binary.BigEndian.PutUint32(output[i:], states[i/16][(i%16)/4])
	}

	//fmt.Printf("aes hash %x\n", output)

}

// these keys are used to generate scratchpad
var AES_GEN_1R_KEY0 = ARRAY_TO_BIGENDIAN([4]uint32{0xb4f44917, 0xdbb5552b, 0x62716609, 0x6daca553})
var AES_GEN_1R_KEY1 = ARRAY_TO_BIGENDIAN([4]uint32{0x0da1dc4e, 0x1725d378, 0x846a710d, 0x6d7caf07})
var AES_GEN_1R_KEY2 = ARRAY_TO_BIGENDIAN([4]uint32{0x3e20e345, 0xf4c0794f, 0x9f947ec6, 0x3f1262f1})
var AES_GEN_1R_KEY3 = ARRAY_TO_BIGENDIAN([4]uint32{0x49169154, 0x16314c88, 0xb1ba317c, 0x6aef8135})

// reverses order of elements and also reverse byte order
func ARRAY_TO_BIGENDIAN(input [4]uint32) (output [4]uint32) {
	for i := range input {
		output[i] = bits.ReverseBytes32(input[i])
	}
	output[0], output[3] = output[3], output[0]
	output[1], output[2] = output[2], output[1]
	return
}

func fillAes1Rx4(state_start []byte, output []byte) {

	var states [4][4]uint32
	for i := 0; i < 63; i += 4 {
		states[i/16][(i%16)/4] = binary.BigEndian.Uint32(state_start[i:])
	}

	outptr := 0
	for ; outptr < len(output); outptr += 64 {
		AES_DEC_ROUND(states[0][:], AES_GEN_1R_KEY0[:])
		AES_ENC_ROUND(states[1][:], AES_GEN_1R_KEY1[:])
		AES_DEC_ROUND(states[2][:], AES_GEN_1R_KEY2[:])
		AES_ENC_ROUND(states[3][:], AES_GEN_1R_KEY3[:])

		for i := 0; i < 63; i += 4 {
			binary.LittleEndian.PutUint32(output[outptr+i:], states[i/16][(i%16)/4])
		}

	}
	// write back to state
	for i := 0; i < 63; i += 4 {

		binary.BigEndian.PutUint32(state_start[i:], states[i/16][(i%16)/4])
	}

}

func AES_ENC_ROUND(state []uint32, key []uint32) {

	s0 := state[0]
	s1 := state[1]
	s2 := state[2]
	s3 := state[3]
	state[0] = key[0] ^ te0[uint8(s0>>24)] ^ te1[uint8(s1>>16)] ^ te2[uint8(s2>>8)] ^ te3[uint8(s3)]
	state[1] = key[1] ^ te0[uint8(s1>>24)] ^ te1[uint8(s2>>16)] ^ te2[uint8(s3>>8)] ^ te3[uint8(s0)]
	state[2] = key[2] ^ te0[uint8(s2>>24)] ^ te1[uint8(s3>>16)] ^ te2[uint8(s0>>8)] ^ te3[uint8(s1)]
	state[3] = key[3] ^ te0[uint8(s3>>24)] ^ te1[uint8(s0>>16)] ^ te2[uint8(s1>>8)] ^ te3[uint8(s2)]
}

func AES_DEC_ROUND(state []uint32, key []uint32) {

	s0 := state[0]
	s1 := state[1]
	s2 := state[2]
	s3 := state[3]

	state[0] = key[0] ^ td0[uint8(s0>>24)] ^ td1[uint8(s3>>16)] ^ td2[uint8(s2>>8)] ^ td3[uint8(s1)]
	state[1] = key[1] ^ td0[uint8(s1>>24)] ^ td1[uint8(s0>>16)] ^ td2[uint8(s3>>8)] ^ td3[uint8(s2)]
	state[2] = key[2] ^ td0[uint8(s2>>24)] ^ td1[uint8(s1>>16)] ^ td2[uint8(s0>>8)] ^ td3[uint8(s3)]
	state[3] = key[3] ^ td0[uint8(s3>>24)] ^ td1[uint8(s2>>16)] ^ td2[uint8(s1>>8)] ^ td3[uint8(s0)]

}

// these keys are used to  used as per RandomX spec
var AES_GEN_4R_KEY0 = ARRAY_TO_BIGENDIAN([4]uint32{0x99e5d23f, 0x2f546d2b, 0xd1833ddb, 0x6421aadd})
var AES_GEN_4R_KEY1 = ARRAY_TO_BIGENDIAN([4]uint32{0xa5dfcde5, 0x06f79d53, 0xb6913f55, 0xb20e3450})
var AES_GEN_4R_KEY2 = ARRAY_TO_BIGENDIAN([4]uint32{0x171c02bf, 0x0aa4679f, 0x515e7baf, 0x5c3ed904})
var AES_GEN_4R_KEY3 = ARRAY_TO_BIGENDIAN([4]uint32{0xd8ded291, 0xcd673785, 0xe78f5d08, 0x85623763})
var AES_GEN_4R_KEY4 = ARRAY_TO_BIGENDIAN([4]uint32{0x229effb4, 0x3d518b6d, 0xe3d6a7a6, 0xb5826f73})
var AES_GEN_4R_KEY5 = ARRAY_TO_BIGENDIAN([4]uint32{0xb272b7d2, 0xe9024d4e, 0x9c10b3d9, 0xc7566bf3})
var AES_GEN_4R_KEY6 = ARRAY_TO_BIGENDIAN([4]uint32{0xf63befa7, 0x2ba9660a, 0xf765a38b, 0xf273c9e7})
var AES_GEN_4R_KEY7 = ARRAY_TO_BIGENDIAN([4]uint32{0xc0b0762d, 0x0c06d1fd, 0x915839de, 0x7a7cd609})

// used to generate final program
func fillAes4Rx4(state_start []byte, output []byte) {

	var states [4][4]uint32
	for i := 0; i < 63; i += 4 {
		states[i/16][(i%16)/4] = binary.BigEndian.Uint32(state_start[i:])
	}

	outptr := 0
	for ; outptr < len(output); outptr += 64 {
		AES_DEC_ROUND(states[0][:], AES_GEN_4R_KEY0[:])
		AES_ENC_ROUND(states[1][:], AES_GEN_4R_KEY0[:])
		AES_DEC_ROUND(states[2][:], AES_GEN_4R_KEY4[:])
		AES_ENC_ROUND(states[3][:], AES_GEN_4R_KEY4[:])

		AES_DEC_ROUND(states[0][:], AES_GEN_4R_KEY1[:])
		AES_ENC_ROUND(states[1][:], AES_GEN_4R_KEY1[:])
		AES_DEC_ROUND(states[2][:], AES_GEN_4R_KEY5[:])
		AES_ENC_ROUND(states[3][:], AES_GEN_4R_KEY5[:])

		AES_DEC_ROUND(states[0][:], AES_GEN_4R_KEY2[:])
		AES_ENC_ROUND(states[1][:], AES_GEN_4R_KEY2[:])
		AES_DEC_ROUND(states[2][:], AES_GEN_4R_KEY6[:])
		AES_ENC_ROUND(states[3][:], AES_GEN_4R_KEY6[:])

		AES_DEC_ROUND(states[0][:], AES_GEN_4R_KEY3[:])
		AES_ENC_ROUND(states[1][:], AES_GEN_4R_KEY3[:])
		AES_DEC_ROUND(states[2][:], AES_GEN_4R_KEY7[:])
		AES_ENC_ROUND(states[3][:], AES_GEN_4R_KEY7[:])

		// store bytes to output buffer
		for i := 0; i < 63; i += 4 {
			binary.BigEndian.PutUint32(output[outptr+i:], states[i/16][(i%16)/4])
		}

	}

}