sm-crypto
Version:
212 lines (190 loc) • 4.69 kB
JavaScript
/**
* 循环左移
*/
function rotl(x, n) {
const result = []
const a = ~~(n / 8) // 偏移 a 字节
const b = n % 8 // 偏移 b 位
for (let i = 0, len = x.length; i < len; i++) {
// current << b + (current + 1) >>> (8 - b)
result[i] = ((x[(i + a) % len] << b) & 0xff) + ((x[(i + a + 1) % len] >>> (8 - b)) & 0xff)
}
return result
}
/**
* 二进制异或运算
*/
function xor(x, y) {
const result = []
for (let i = x.length - 1; i >= 0; i--) result[i] = (x[i] ^ y[i]) & 0xff
return result
}
/**
* 二进制与运算
*/
function and(x, y) {
const result = []
for (let i = x.length - 1; i >= 0; i--) result[i] = (x[i] & y[i]) & 0xff
return result
}
/**
* 二进制或运算
*/
function or(x, y) {
const result = []
for (let i = x.length - 1; i >= 0; i--) result[i] = (x[i] | y[i]) & 0xff
return result
}
/**
* 二进制与运算
*/
function add(x, y) {
const result = []
let temp = 0
for (let i = x.length - 1; i >= 0; i--) {
const sum = x[i] + y[i] + temp
if (sum > 0xff) {
temp = 1
result[i] = sum & 0xff
} else {
temp = 0
result[i] = sum & 0xff
}
}
return result
}
/**
* 二进制非运算
*/
function not(x) {
const result = []
for (let i = x.length - 1; i >= 0; i--) result[i] = (~x[i]) & 0xff
return result
}
/**
* 压缩函数中的置换函数 P1(X) = X xor (X <<< 9) xor (X <<< 17)
*/
function P0(X) {
return xor(xor(X, rotl(X, 9)), rotl(X, 17))
}
/**
* 消息扩展中的置换函数 P1(X) = X xor (X <<< 15) xor (X <<< 23)
*/
function P1(X) {
return xor(xor(X, rotl(X, 15)), rotl(X, 23))
}
/**
* 布尔函数 FF
*/
function FF(X, Y, Z, j) {
return j >= 0 && j <= 15 ? xor(xor(X, Y), Z) : or(or(and(X, Y), and(X, Z)), and(Y, Z))
}
/**
* 布尔函数 GG
*/
function GG(X, Y, Z, j) {
return j >= 0 && j <= 15 ? xor(xor(X, Y), Z) : or(and(X, Y), and(not(X), Z))
}
/**
* 压缩函数
*/
function CF(V, Bi) {
// 消息扩展
const W = []
const M = [] // W'
// 将消息分组B划分为 16 个字 W0， W1，……，W15
for (let i = 0; i < 16; i++) {
const start = i * 4
W.push(Bi.slice(start, start + 4))
}
// W16 ～ W67：W[j] <- P1(W[j−16] xor W[j−9] xor (W[j−3] <<< 15)) xor (W[j−13] <<< 7) xor W[j−6]
for (let j = 16; j < 68; j++) {
W.push(xor(
xor(
P1(
xor(
xor(W[j - 16], W[j - 9]),
rotl(W[j - 3], 15)
)
),
rotl(W[j - 13], 7)
),
W[j - 6]
))
}
// W′0 ～ W′63：W′[j] = W[j] xor W[j+4]
for (let j = 0; j < 64; j++) {
M.push(xor(W[j], W[j + 4]))
}
// 压缩
const T1 = [0x79, 0xcc, 0x45, 0x19]
const T2 = [0x7a, 0x87, 0x9d, 0x8a]
// 字寄存器
let A = V.slice(0, 4)
let B = V.slice(4, 8)
let C = V.slice(8, 12)
let D = V.slice(12, 16)
let E = V.slice(16, 20)
let F = V.slice(20, 24)
let G = V.slice(24, 28)
let H = V.slice(28, 32)
// 中间变量
let SS1
let SS2
let TT1
let TT2
for (let j = 0; j < 64; j++) {
const T = j >= 0 && j <= 15 ? T1 : T2
SS1 = rotl(add(
add(rotl(A, 12), E),
rotl(T, j)
), 7)
SS2 = xor(SS1, rotl(A, 12))
TT1 = add(add(add(FF(A, B, C, j), D), SS2), M[j])
TT2 = add(add(add(GG(E, F, G, j), H), SS1), W[j])
D = C
C = rotl(B, 9)
B = A
A = TT1
H = G
G = rotl(F, 19)
F = E
E = P0(TT2)
}
return xor([].concat(A, B, C, D, E, F, G, H), V)
}
module.exports = function (array) {
// 填充
let len = array.length * 8
// k 是满足 len + 1 + k = 448mod512 的最小的非负整数
let k = len % 512
// 如果 448 <= (512 % len) < 512，需要多补充 (len % 448) 比特'0'以满足总比特长度为512的倍数
k = k >= 448 ? 512 - (k % 448) - 1 : 448 - k - 1
// 填充
const kArr = new Array((k - 7) / 8)
for (let i = 0, len = kArr.length; i < len; i++) kArr[i] = 0
const lenArr = []
len = len.toString(2)
for (let i = 7; i >= 0; i--) {
if (len.length > 8) {
const start = len.length - 8
lenArr[i] = parseInt(len.substr(start), 2)
len = len.substr(0, start)
} else if (len.length > 0) {
lenArr[i] = parseInt(len, 2)
len = ''
} else {
lenArr[i] = 0
}
}
const m = [].concat(array, [0x80], kArr, lenArr)
// 迭代压缩
const n = m.length / 64
let V = [0x73, 0x80, 0x16, 0x6f, 0x49, 0x14, 0xb2, 0xb9, 0x17, 0x24, 0x42, 0xd7, 0xda, 0x8a, 0x06, 0x00, 0xa9, 0x6f, 0x30, 0xbc, 0x16, 0x31, 0x38, 0xaa, 0xe3, 0x8d, 0xee, 0x4d, 0xb0, 0xfb, 0x0e, 0x4e]
for (let i = 0; i < n; i++) {
const start = 64 * i
const B = m.slice(start, start + 64)
V = CF(V, B)
}
return V
}