ictscのhash.go

hash.go

package main

import (
	"fmt"
)

func Uint64ToBytes(v uint64) []byte {
	var result []byte
	for i := 64 - 8; i >= 0; i -= 8 {
		result = append(result, byte((v>>uint64(i))&0xff))
	}
	return result
}

func BytesToUint32(b []byte) []uint32 {
	var result []uint32
	for i := 0; i < len(b)-3; i += 4 {
		result = append(result, uint32((uint32(b[i])<<24)|(uint32(b[i+1])<<16)|(uint32(b[i+2])<<8)|(uint32(b[i+3]))))
	}
	return result
}

func ROTL(n uint, x uint32) uint32 {
	return (x << n) | (x >> (32 - n))
}

func ROTR(n uint, x uint32) uint32 {
	return (x >> n) | (x << (32 - n))
}

func SHR(n uint, x uint32) uint32 {
	return (x >> n)
}

func Ch(x, y, z uint32) uint32 {
	return (x & y) ^ (^x & z)
}

func Maj(x, y, z uint32) uint32 {
	return (x & y) ^ (x & z) ^ (y & z)
}

func BigSigma0(x uint32) uint32 {
	return (ROTR(2, x) ^ ROTR(13, x) ^ ROTR(22, x))
}

func BigSigma1(x uint32) uint32 {
	return (ROTR(6, x) ^ ROTR(11, x) ^ ROTR(25, x))
}

func SmallSigma0(x uint32) uint32 {
	return (ROTR(7, x) ^ ROTR(18, x) ^ SHR(3, x))
}

func SmallSigma1(x uint32) uint32 {
	return (ROTR(17, x) ^ ROTR(19, x) ^ SHR(10, x))
}

func Padding(M []byte) []byte {
	// 1 byte = 8 bit
	var k int
	switch d := len(M) % 64; {
	case d == 55:
		k = 0
	case d < 55:
		k = 55 - d
	case 55 < d:
		k = 64 + 55 - d
	}

	return append(append(append(M[:], 0x80), make([]byte, k)...), Uint64ToBytes(uint64(len(M)*8))...)
}

func main() {
	K := []uint32{0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2}

	H := []uint32{0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19}

	var input string
	fmt.Printf("data: ")
	fmt.Scan(&input)

	binputs := []byte(input)
	padded := Padding(binputs)
	words := BytesToUint32(padded)

	for i := 0; i < len(words)/16; i++ {
		W := make([]uint32, 64)
		for t, _ := range W {
			if 0 <= t && t <= 15 {
				W[t] = words[(i*16)+t]
				// fmt.Printf("%08x\n", W[t])
			} else if 16 <= t && t <= 63 {
				W[t] = SmallSigma1(W[t-2]) + W[t-7] + SmallSigma0(W[t-15]) + W[t-16]
				// fmt.Printf("%02d  %08x  %08x  %08x  %08x  %08x\n", t, W[t], W[t-2], W[t-7], W[t-15], W[t-16])
			}
		}

		var a, b, c, d, e, f, g, h = H[0], H[1], H[2], H[3], H[4], H[5], H[6], H[7]

		for t := 0; t < 64; t++ {
			T1 := h + BigSigma1(e) + Ch(e, f, g) + K[t] + W[t]
			T2 := BigSigma0(a) + Maj(a, b, c)
			h = g
			g = f
			f = e
			e = d + T1
			d = c
			c = b
			b = a
			a = T1 + T2
			// fmt.Printf("%02d:%08x  %08x  %08x  %08x  %08x  %08x  %08x  %08x\n", t, a, b, c, d, e, f, g, h)
		}

		H[0] += a
		H[1] += b
		H[2] += c
		H[3] += d
		H[4] += e
		H[5] += f
		H[6] += g
		H[7] += h
	}

	fmt.Printf("SHA256: %08x%08x%08x%08x%08x%08x%08x%08x\n", H[0], H[1], H[2], H[3], H[4], H[5], H[6], H[7])

}