前言:
趁热打铁,标记一下RSA的算法逆向...第二篇会有详解(本篇重在过程)
正文:
废话不说,直接分析步骤图:
到了这里,可以看到在登录的时候,需要验证码(本篇不教反验证码)
下面是正题--->逆他的pwd(密码)
总结:
问题:怎么确定一个密文数据是基于什么算法做出来的呢?
答: 1.看他是由什么组成的
- --如果光是由 '字母和数字'组成
- --由字母和数字组成的32位密文数据 ,MD5
- --由字母和数字组成的64位密文数据 ,SHA-256(生成256位长度的哈希值，这通常以64个十六进制字符呈现)
- --由字母和数字组成的256位密文数据,RSA
- ---以上是通常的例子
针对rsa,直接抠他代码会比较直接,但是比较繁琐; 当你过了一遍他的代码,没大问题,一样可以引用crypto库进行解密
全篇js代码:
var bitsPerDigit=16
function arrayCopy(src, srcStart, dest, destStart, n)
{
var m = Math.min(srcStart + n, src.length);
for (var i = srcStart, j = destStart; i < m; ++i, ++j) {
dest[j] = src[i];
}
}
var maxDigitVal = 65535
var biRadixBits =16
function biMultiplyDigit(x, y)
{
var n, c, uv;
result = new BigInt();
n = biHighIndex(x);
c = 0;
for (var j = 0; j <= n; ++j) {
uv = result.digits[j] + x.digits[j] * y + c;
result.digits[j] = uv & maxDigitVal;
c = uv >>> biRadixBits;
}
result.digits[1 + n] = c;
return result;
}
function biNumBits(x)
{
var n = biHighIndex(x);
var d = x.digits[n];
var m = (n + 1) * bitsPerDigit;
var result;
for (result = m; result > m - bitsPerDigit; --result) {
if ((d & 0x8000) != 0) break;
d <<= 1;
}
return result;
}
var highBitMasks = new Array(0x0000, 0x8000, 0xC000, 0xE000, 0xF000, 0xF800,
0xFC00, 0xFE00, 0xFF00, 0xFF80, 0xFFC0, 0xFFE0,
0xFFF0, 0xFFF8, 0xFFFC, 0xFFFE, 0xFFFF);
function biShiftLeft(x, n)
{
var maxDigitVal= 65535
var digitCount = Math.floor(n / bitsPerDigit);
var result = new BigInt();
arrayCopy(x.digits, 0, result.digits, digitCount,
result.digits.length - digitCount);
var bits = n % bitsPerDigit;
var rightBits = bitsPerDigit - bits;
for (var i = result.digits.length - 1, i1 = i - 1; i > 0; --i, --i1) {
result.digits[i] = ((result.digits[i] << bits) & maxDigitVal) |
((result.digits[i1] & highBitMasks[bits]) >>>
(rightBits));
}
result.digits[0] = ((result.digits[i] << bits) & maxDigitVal);
result.isNeg = x.isNeg;
return result;
}
function biMultiplyByRadixPower(x, n)
{
var result = new BigInt();
arrayCopy(x.digits, 0, result.digits, n, result.digits.length - n);
return result;
}
function biCompare(x, y)
{
if (x.isNeg != y.isNeg) {
return 1 - 2 * Number(x.isNeg);
}
for (var i = x.digits.length - 1; i >= 0; --i) {
if (x.digits[i] != y.digits[i]) {
if (x.isNeg) {
return 1 - 2 * Number(x.digits[i] > y.digits[i]);
} else {
return 1 - 2 * Number(x.digits[i] < y.digits[i]);
}
}
}
return 0;
}
function biSubtract(x, y)
{
var result;
if (x.isNeg != y.isNeg) {
y.isNeg = !y.isNeg;
result = biAdd(x, y);
y.isNeg = !y.isNeg;
} else {
result = new BigInt();
var n, c;
c = 0;
for (var i = 0; i < x.digits.length; ++i) {
n = x.digits[i] - y.digits[i] + c;
result.digits[i] = n & 0xffff;
// Stupid non-conforming modulus operation.
if (result.digits[i] < 0) result.digits[i] += biRadix;
c = 0 - Number(n < 0);
}
// Fix up the negative sign, if any.
if (c == -1) {
c = 0;
for (var i = 0; i < x.digits.length; ++i) {
n = 0 - result.digits[i] + c;
result.digits[i] = n & 0xffff;
// Stupid non-conforming modulus operation.
if (result.digits[i] < 0) result.digits[i] += biRadix;
c = 0 - Number(n < 0);
}
// Result is opposite sign of arguments.
result.isNeg = !x.isNeg;
} else {
// Result is same sign.
result.isNeg = x.isNeg;
}
}
return result;
}
var lowBitMasks = new Array(0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F,
0x003F, 0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF,
0x0FFF, 0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF);
function biShiftRight(x, n)
{
var digitCount = Math.floor(n / bitsPerDigit);
var result = new BigInt();
arrayCopy(x.digits, digitCount, result.digits, 0,
x.digits.length - digitCount);
var bits = n % bitsPerDigit;
var leftBits = bitsPerDigit - bits;
for (var i = 0, i1 = i + 1; i < result.digits.length - 1; ++i, ++i1) {
result.digits[i] = (result.digits[i] >>> bits) |
((result.digits[i1] & lowBitMasks[bits]) << leftBits);
}
result.digits[result.digits.length - 1] >>>= bits;
result.isNeg = x.isNeg;
return result;
}
function biDivideModulo(x, y)
{
var nb = biNumBits(x);
var tb = biNumBits(y);
var origYIsNeg = y.isNeg;
var q, r;
if (nb < tb) {
// |x| < |y|
if (x.isNeg) {
q = biCopy(bigOne);
q.isNeg = !y.isNeg;
x.isNeg = false;
y.isNeg = false;
r = biSubtract(y, x);
// Restore signs, 'cause they're references.
x.isNeg = true;
y.isNeg = origYIsNeg;
} else {
q = new BigInt();
r = biCopy(x);
}
return new Array(q, r);
}
q = new BigInt();
r = x;
var bitsPerDigit =16
// Normalize Y.
var t = Math.ceil(tb / bitsPerDigit) - 1;
var lambda = 0;
var biHalfRadix= 32768
while (y.digits[t] < biHalfRadix) {
y = biShiftLeft(y, 1);
++lambda;
++tb;
t = Math.ceil(tb / bitsPerDigit) - 1;
}
// Shift r over to keep the quotient constant. We'll shift the
// remainder back at the end.
r = biShiftLeft(r, lambda);
nb += lambda; // Update the bit count for x.
var n = Math.ceil(nb / bitsPerDigit) - 1;
var b = biMultiplyByRadixPower(y, n - t);
while (biCompare(r, b) != -1) {
++q.digits[n - t];
r = biSubtract(r, b);
}
for (var i = n; i > t; --i) {
var ri = (i >= r.digits.length) ? 0 : r.digits[i];
var ri1 = (i - 1 >= r.digits.length) ? 0 : r.digits[i - 1];
var ri2 = (i - 2 >= r.digits.length) ? 0 : r.digits[i - 2];
var yt = (t >= y.digits.length) ? 0 : y.digits[t];
var biRadix = 65536
var yt1 = (t - 1 >= y.digits.length) ? 0 : y.digits[t - 1];
if (ri == yt) {
q.digits[i - t - 1] = maxDigitVal;
} else {
q.digits[i - t - 1] = Math.floor((ri * biRadix + ri1) / yt);
}
var biRadixSquared =4294967296
var c1 = q.digits[i - t - 1] * ((yt * biRadix) + yt1);
var c2 = (ri * biRadixSquared) + ((ri1 * biRadix) + ri2);
while (c1 > c2) {
--q.digits[i - t - 1];
c1 = q.digits[i - t - 1] * ((yt * biRadix) | yt1);
c2 = (ri * biRadix * biRadix) + ((ri1 * biRadix) + ri2);
}
b = biMultiplyByRadixPower(y, i - t - 1);
r = biSubtract(r, biMultiplyDigit(b, q.digits[i - t - 1]));
if (r.isNeg) {
r = biAdd(r, b);
--q.digits[i - t - 1];
}
}
r = biShiftRight(r, lambda);
// Fiddle with the signs and stuff to make sure that 0 <= r < y.
q.isNeg = x.isNeg != origYIsNeg;
if (x.isNeg) {
if (origYIsNeg) {
q = biAdd(q, bigOne);
} else {
q = biSubtract(q, bigOne);
}
y = biShiftRight(y, lambda);
r = biSubtract(y, r);
}
// Check for the unbelievably stupid degenerate case of r == -0.
if (r.digits[0] == 0 && biHighIndex(r) == 0) r.isNeg = false;
return new Array(q, r);
}
function biDivide(x, y)
{
return biDivideModulo(x, y)[0];
}
function biCopy(bi)
{
var result = new BigInt(true);
result.digits = bi.digits.slice(0);
result.isNeg = bi.isNeg;
return result;
}
function biDivideByRadixPower(x, n)
{
var result = new BigInt();
arrayCopy(x.digits, n, result.digits, 0, result.digits.length - n);
return result;
}
function biModuloByRadixPower(x, n)
{
var result = new BigInt();
arrayCopy(x.digits, 0, result.digits, 0, n);
return result;
}
function BarrettMu_modulo(x)
{
var q1 = biDivideByRadixPower(x, this.k - 1);
var q2 = biMultiply(q1, this.mu);
var q3 = biDivideByRadixPower(q2, this.k + 1);
var r1 = biModuloByRadixPower(x, this.k + 1);
var r2term = biMultiply(q3, this.modulus);
var r2 = biModuloByRadixPower(r2term, this.k + 1);
var r = biSubtract(r1, r2);
if (r.isNeg) {
r = biAdd(r, this.bkplus1);
}
var rgtem = biCompare(r, this.modulus) >= 0;
while (rgtem) {
r = biSubtract(r, this.modulus);
rgtem = biCompare(r, this.modulus) >= 0;
}
return r;
}
function biMultiply(x, y)
{
var result = new BigInt();
var c;
var n = biHighIndex(x);
var t = biHighIndex(y);
var u, uv, k;
for (var i = 0; i <= t; ++i) {
c = 0;
k = i;
for (j = 0; j <= n; ++j, ++k) {
uv = result.digits[k] + x.digits[j] * y.digits[i] + c;
result.digits[k] = uv & maxDigitVal;
c = uv >>> biRadixBits;
}
result.digits[i + n + 1] = c;
}
// Someone give me a logical xor, please.
result.isNeg = x.isNeg != y.isNeg;
return result;
}
function BarrettMu_multiplyMod(x, y)
{
/*
x = this.modulo(x);
y = this.modulo(y);
*/
var xy = biMultiply(x, y);
return this.modulo(xy);
}
function BarrettMu_powMod(x, y)
{
var result = new BigInt();
result.digits[0] = 1;
var a = x;
var k = y;
while (true) {
if ((k.digits[0] & 1) != 0) result = this.multiplyMod(result, a);
k = biShiftRight(k, 1);
if (k.digits[0] == 0 && biHighIndex(k) == 0) break;
a = this.multiplyMod(a, a);
}
return result;
}
function BarrettMu(m)
{
this.modulus = biCopy(m);
this.k = biHighIndex(this.modulus) + 1;
var b2k = new BigInt();
b2k.digits[2 * this.k] = 1; // b2k = b^(2k)
this.mu = biDivide(b2k, this.modulus);
this.bkplus1 = new BigInt();
this.bkplus1.digits[this.k + 1] = 1; // bkplus1 = b^(k+1)
this.modulo = BarrettMu_modulo;
this.multiplyMod = BarrettMu_multiplyMod;
this.powMod = BarrettMu_powMod;
}
function charToHex(c)
{
var ZERO = 48;
var NINE = ZERO + 9;
var littleA = 97;
var littleZ = littleA + 25;
var bigA = 65;
var bigZ = 65 + 25;
var result;
if (c >= ZERO && c <= NINE) {
result = c - ZERO;
} else if (c >= bigA && c <= bigZ) {
result = 10 + c - bigA;
} else if (c >= littleA && c <= littleZ) {
result = 10 + c - littleA;
} else {
result = 0;
}
return result;
}
function hexToDigit(s)
{
var result = 0;
var sl = Math.min(s.length, 4);
for (var i = 0; i < sl; ++i) {
result <<= 4;
result |= charToHex(s.charCodeAt(i))
}
return result;
}
function biHighIndex(x)
{
var result = x.digits.length - 1;
while (result > 0 && x.digits[result] == 0) --result;
return result;
}
function biFromHex(s)
{
var result = new BigInt();
var sl = s.length;
for (var i = sl, j = 0; i > 0; i -= 4, ++j) {
result.digits[j] = hexToDigit(s.substr(Math.max(i - 4, 0), Math.min(i, 4)));
}
return result;
}
function RSAKeyPair(encryptionExponent, decryptionExponent, modulus, keylen)
{
this.e = biFromHex(encryptionExponent);
this.d = biFromHex(decryptionExponent);
this.m = biFromHex(modulus);
if (typeof(keylen) != 'number') { this.chunkSize = 2 * biHighIndex(this.m); }
else { this.chunkSize = keylen / 8; }
this.radix = 16;
this.barrett = new BarrettMu(this.m);
}
function BigInt(flag)
{
if (typeof flag == "boolean" && flag == true) {
this.digits = null;
}
else {
this.digits = ZERO_ARRAY.slice(0);
}
this.isNeg = false;
}
function setMaxDigits(value)
{
maxDigits = value;
ZERO_ARRAY = new Array(maxDigits);
for (var iza = 0; iza < ZERO_ARRAY.length; iza++) ZERO_ARRAY[iza] = 0;
bigZero = new BigInt();
bigOne = new BigInt();
bigOne.digits[0] = 1;
}
var hexToChar = new Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f');
function reverseStr(s)
{
var result = "";
for (var i = s.length - 1; i > -1; --i) {
result += s.charAt(i);
}
return result;
}
function digitToHex(n)
{
var mask = 0xf;
var result = "";
for (i = 0; i < 4; ++i) {
result += hexToChar[n & mask];
n >>>= 4;
}
return reverseStr(result);
}
function biToHex(x)
{
var result = "";
var n = biHighIndex(x);
for (var i = biHighIndex(x); i > -1; --i) {
result += digitToHex(x.digits[i]);
}
return result;
}
function encryptedString(key, s, pad, encoding) {
var a = new Array(); // The usual Alice and Bob stuff
var sl = s.length; // Plaintext string length
var i, j, k; // The usual Fortran index stuff
var padtype; // Type of padding to do
var encodingtype; // Type of output encoding
var rpad; // Random pad
var al; // Array length
var result = ""; // Cypthertext result
var block; // Big integer block to encrypt
var crypt; // Big integer result
var text; // Text result
/*
* Figure out the padding type.
*/
if (typeof (pad) == 'string') {
if (pad == RSAAPP.NoPadding) {
padtype = 1;
} else if (pad == RSAAPP.PKCS1Padding) {
padtype = 2;
} else {
padtype = 0;
}
} else {
padtype = 0;
}
/*
* Determine encoding type.
*/
if (typeof (encoding) == 'string' && encoding == RSAAPP.RawEncoding) {
encodingtype = 1;
} else {
encodingtype = 0;
}
if (padtype == 1) {
if (sl > key.chunkSize) {
sl = key.chunkSize;
}
} else if (padtype == 2) {
if (sl > (key.chunkSize - 11)) {
sl = key.chunkSize - 11;
}
}
i = 0;
if (padtype == 2) {
j = sl - 1;
} else {
j = key.chunkSize - 1;
}
while (i < sl) {
if (padtype) {
a[j] = s.charCodeAt(i);
} else {
a[i] = s.charCodeAt(i);
}
i++;
j--;
}
if (padtype == 1) {
i = 0;
}
j = key.chunkSize - (sl % key.chunkSize);
while (j > 0) {
if (padtype == 2) {
rpad = Math.floor(Math.random() * 256);
while (!rpad) {
rpad = Math.floor(Math.random() * 256);
}
a[i] = rpad;
} else {
a[i] = 0;
}
i++;
j--;
}
if (padtype == 2) {
a[sl] = 0;
a[key.chunkSize - 2] = 2;
a[key.chunkSize - 1] = 0;
}
/*
* Carve up the plaintext and encrypt each of the resultant blocks.
*/
al = a.length;
for (i = 0; i < al; i += key.chunkSize) {
/*
* Get a block.
*/
block = new BigInt();
j = 0;
for (k = i; k < (i + key.chunkSize); ++j) {
block.digits[j] = a[k++];
block.digits[j] += a[k++] << 8;
}
/*
* Encrypt it, convert it to text, and append it to the result.
*/
crypt = key.barrett.powMod(block, key.e);
if (encodingtype == 1) {
text = biToBytes(crypt);
} else {
text = (key.radix == 16) ? biToHex(crypt) : biToString(crypt, key.radix);
}
result += text;
}
/*
* Return the result, removing the last space.
*/
//result = (result.substring(0, result.length - 1));
return result;
}
function rsa(arg) {
setMaxDigits(130);
var PublicExponent = "10001";
var modulus = "be44aec4d73408f6b60e6fe9e3dc55d0e1dc53a1e171e071b547e2e8e0b7da01c56e8c9bcf0521568eb111adccef4e40124b76e33e7ad75607c227af8f8e0b759c30ef283be8ab17a84b19a051df5f94c07e6e7be5f77866376322aac944f45f3ab532bb6efc70c1efa524d821d16cafb580c5a901f0defddea3692a4e68e6cd";
var key = new RSAKeyPair(PublicExponent, "", modulus);
// console.log(key, arg) 验证看一下 -->自己出错了没?
return encryptedString(key, arg);
};
console.log(rsa("输入你的密码"))
(预告---下篇,详解本章的代码)
