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MD5 & SHA

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安全
算法结构

MD5

什么是破解？

已知A，通过MD5计算后得出AB, 那么破解的过程就是能够找到一种方法使得通过AB能够得到原始的A。比如说有没有可能找到MD5的逆过程，通过这个MD5逆过程反向找到原始的A？

那么MD5能破解吗？

不能的， MD5是单向的，根本就没有这样一个可逆的过程！

所谓MD5破解

目前网上充斥着各种所谓的MD5破解方法，那根本就不是什么破解，整理出来基本都是个“猜”。这里整理了下网上所谓的MD5破解大发：

1、猜

2、暴力破解

3、查字典，彩虹表

4、这里不想将山大王小云教授这种方式列在此处

王小云教授的这种方法也是一种可能的方式，但也并没有破解出MD5。附件中留有相关论文。

除此之外好像听说某视频网站公司声称真的破解了MD5，如果不是瞎扯蛋，能把具体破解算法公布出来吗？这不应该是什么机密吧。

MD5

MD5中的几个变换函数

初始化MD Buffer

// state of this object
private int[] state;

state = new int[4];

void implReset() {
	// Load magic initialization constants.
	state[0] = 0x67452301;
	state[1] = 0xefcdab89;
	state[2] = 0x98badcfe;
	state[3] = 0x10325476;
}

private static int A = 0x67452301;
private static int B = 0xefcdab89;
private static int C = 0x98badcfe;
private static int D = 0x10325476;

四个辅助函数：

F(X,Y,Z) = XY v not(X) Z

G(X,Y,Z) = XZ v Y not(Z)

H(X,Y,Z) = X xor Y xor Z

I(X,Y,Z) = Y xor (X v not(Z))

// F(X,Y,Z) = XY v not(X) Z
// #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
private static int F(int x, int y, int z) {
	return (((x) & (y)) | ((~x) & (z)));
}

// G(X,Y,Z) = XZ v Y not(Z)
// #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
private static int G(int x, int y, int z) {
	return (((x) & (z)) | ((y) & (~z)));
}

// H(X,Y,Z) = X xor Y xor Z
// #define H(x, y, z) ((x) ^ (y) ^ (z))
private static int H(int x, int y, int z) {
	return ((x) ^ (y) ^ (z));
}

// I(X,Y,Z) = Y xor (X v not(Z))
// #define I(x, y, z) ((y) ^ ((x) | (~z)))
private static int I(int x, int y, int z) {
	return ((y) ^ ((x) | (~z)));
}

// #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
private static int rotateLeft(int x, int n) {
	return (((x) << (n)) | ((x) >> (32-(n))));
}

// #define FF(a, b, c, d, x, s, ac) { \
//  (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
//  (a) = ROTATE_LEFT ((a), (s)); \
//  (a) += (b); \
//   }
private static int FF(int a, int b, int c, int d, int x, int s, int ac) {
	a += F(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a += b;
	return a;
}

// #define GG(a, b, c, d, x, s, ac) { \
//	(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
//	(a) = ROTATE_LEFT ((a), (s)); \
//	(a) += (b); \
//	 }
private static int GG(int a, int b, int c, int d, int x, int s, int ac) {
	a += G(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a += b;
	return a;
}

// #define HH(a, b, c, d, x, s, ac) { \
//  (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
//  (a) = ROTATE_LEFT ((a), (s)); \
//  (a) += (b); \
//   }
private static int HH(int a, int b, int c, int d, int x, int s, int ac) {
	a += H(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a += b;
	return a;
}

// #define II(a, b, c, d, x, s, ac) { \
//  (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
//  (a) = ROTATE_LEFT ((a), (s)); \
//  (a) += (b); \
//   }
private static int II(int a, int b, int c, int d, int x, int s, int ac) {
	a += I(b, c, d) + x + ac;
	a = rotateLeft(a, s);
	a += b;
	return a;
}

Java中MD5的实现代码在sun.security.provider.MD5中。

Provider: sun.security.provider.Sun

但里边的方法都不对外开放，不能直接访问。

private static final char[] HEX_CHAR = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};;

@Test
public void md5() {
    String message = "13120084002";
    MessageDigest md5 = null;
    try {
        md5 = MessageDigest.getInstance("MD5");
    } catch (NoSuchAlgorithmException e) {
        Assert.fail(e.getMessage());
    }
    byte[] digest = md5.digest(message.getBytes());
    Assert.assertNotNull(digest);
    Assert.assertEquals(16, digest.length); // length of digest must be 16: 128bits
StringBuilder sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        byte j = digest[i];
        int h = j >> 4 & 0x0f;
        int l = j & 0x0f;
        sb.append(Integer.toHexString(h));
        sb.append(Integer.toHexString(l));
    }
    String result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        sb.append(String.format("%02x", new Integer(digest[i] & 0xff)));
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        int j = digest[i];
        if(digest[i] < 0) {
            j = 256 + digest[i];
        }
        sb.append(HEX_CHAR[j / 16]);
        sb.append(HEX_CHAR[j % 16]);
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    result = Base64.byteArrayToBase64(digest);
    System.out.println(message + "(base64:" + result + ")");
}

13120084002(hex:4dccd5cf34d388df98643f66866366b1)
13120084002(hex:4dccd5cf34d388df98643f66866366b1)
13120084002(hex:4dccd5cf34d388df98643f66866366b1)
13120084002(base64:TczVzzTTiN+YZD9mhmNmsQ==)

The MD5 Message-Digest Algorithm, https://tools.ietf.org/html/rfc1321

The MD4 Message-Digest Algorithm, https://tools.ietf.org/html/rfc1320

The MD4 Message Digest Algorithm, https://tools.ietf.org/html/rfc1186

The MD2 Message-Digest Algorithm, https://tools.ietf.org/html/rfc1319

SHA

Java中US Secure Hash Algorithm 1 (SHA1)实现：

sun.security.provider.SHA

Java中没提供SHA-224实现。

Java中Secure Hash Algorithm SHA-256实现：

sun.security.provider.SHA2

Java中Secure Hash Algorithm SHA-384 and SHA-512实现：

sun.security.provider.SHA5

其中SHA-384实现sun.security.provider.SHA5.SHA384，SHA-512实现sun.security.provider.SHA5.SHA512

SHA1

f(t;B,C,D) = (B AND C) OR ((NOT B) AND D) ( 0 <= t <= 19)

f(t;B,C,D) = B XOR C XOR D (20 <= t <= 39)

f(t;B,C,D) = (B AND C) OR (B AND D) OR (C AND D) (40 <= t <= 59)

f(t;B,C,D) = B XOR C XOR D (60 <= t <= 79)

SHA-224 and SHA-256

CH( x, y, z) = (x AND y) XOR ( (NOT x) AND z)

MAJ( x, y, z) = (x AND y) XOR (x AND z) XOR (y AND z)

BSIG0(x) = ROTR^2(x) XOR ROTR^13(x) XOR ROTR^22(x)

BSIG1(x) = ROTR^6(x) XOR ROTR^11(x) XOR ROTR^25(x)

SSIG0(x) = ROTR^7(x) XOR ROTR^18(x) XOR SHR^3(x)

SSIG1(x) = ROTR^17(x) XOR ROTR^19(x) XOR SHR^10(x)

SHA-384 and SHA-512

CH( x, y, z) = (x AND y) XOR ( (NOT x) AND z)

MAJ( x, y, z) = (x AND y) XOR (x AND z) XOR (y AND z)

BSIG0(x) = ROTR^28(x) XOR ROTR^34(x) XOR ROTR^39(x)

BSIG1(x) = ROTR^14(x) XOR ROTR^18(x) XOR ROTR^41(x)

SSIG0(x) = ROTR^1(x) XOR ROTR^8(x) XOR SHR^7(x)

SSIG1(x) = ROTR^19(x) XOR ROTR^61(x) XOR SHR^6(x)

Java中US Secure Hash Algorithm 1 (SHA1)实例：

@Test
public void sha1() {
    String message = "13120084002";
    MessageDigest sha1 = null;
    try {
        sha1 = MessageDigest.getInstance("SHA1");
    } catch (NoSuchAlgorithmException e) {
        Assert.fail(e.getMessage());
    }
    byte[] digest = sha1.digest(message.getBytes());
    Assert.assertNotNull(digest);
    Assert.assertEquals(20, digest.length); // length of digest must be 20: 160bits

    StringBuilder sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        byte j = digest[i];
        int h = j >> 4 & 0x0f;
        int l = j & 0x0f;
        sb.append(Integer.toHexString(h));
        sb.append(Integer.toHexString(l));
    }
    String result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        sb.append(String.format("%02x", new Integer(digest[i] & 0xff)));
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        int j = digest[i];
        if(digest[i] < 0) {
            j = 256 + digest[i];
        }
        sb.append(HEX_CHAR[j / 16]);
        sb.append(HEX_CHAR[j % 16]);
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    result = Base64.byteArrayToBase64(digest);
    System.out.println(message + "(base64:" + result + ")");
}

Java中Secure Hash Algorithm SHA-256实例：

@Test
public void sha256() {
    String message = "13120084002";
    MessageDigest sha256 = null;
    try {
        sha256 = MessageDigest.getInstance("SHA-256");
    } catch (NoSuchAlgorithmException e) {
        Assert.fail(e.getMessage());
    }
    byte[] digest = sha256.digest(message.getBytes());
    Assert.assertNotNull(digest);
    Assert.assertEquals(32, digest.length); // length of digest must be 32: 256bits

    StringBuilder sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        byte j = digest[i];
        int h = j >> 4 & 0x0f;
        int l = j & 0x0f;
        sb.append(Integer.toHexString(h));
        sb.append(Integer.toHexString(l));
    }
    String result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        sb.append(String.format("%02x", new Integer(digest[i] & 0xff)));
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        int j = digest[i];
        if(digest[i] < 0) {
            j = 256 + digest[i];
        }
        sb.append(HEX_CHAR[j / 16]);
        sb.append(HEX_CHAR[j % 16]);
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    result = Base64.byteArrayToBase64(digest);
    System.out.println(message + "(base64:" + result + ")");
}

Java中Secure Hash Algorithm SHA-384实例：

@Test
public void sha384() {
    String message = "13120084002";
    MessageDigest sha384 = null;
    try {
        sha384 = MessageDigest.getInstance("SHA-384");
    } catch (NoSuchAlgorithmException e) {
        Assert.fail(e.getMessage());
    }
    byte[] digest = sha384.digest(message.getBytes());
    Assert.assertNotNull(digest);
    Assert.assertEquals(48, digest.length); // length of digest must be 48: 384bits

    StringBuilder sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        byte j = digest[i];
        int h = j >> 4 & 0x0f;
        int l = j & 0x0f;
        sb.append(Integer.toHexString(h));
        sb.append(Integer.toHexString(l));
    }
    String result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        sb.append(String.format("%02x", new Integer(digest[i] & 0xff)));
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        int j = digest[i];
        if(digest[i] < 0) {
            j = 256 + digest[i];
        }
        sb.append(HEX_CHAR[j / 16]);
        sb.append(HEX_CHAR[j % 16]);
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    result = Base64.byteArrayToBase64(digest);
    System.out.println(message + "(base64:" + result + ")");
}

Java中Secure Hash Algorithm SHA-512实例：

@Test
public void sha512() {
    String message = "13120084002";
    MessageDigest sha512 = null;
    try {
        sha512 = MessageDigest.getInstance("SHA-512");
    } catch (NoSuchAlgorithmException e) {
        Assert.fail(e.getMessage());
    }
    byte[] digest = sha512.digest(message.getBytes());
    Assert.assertNotNull(digest);
    Assert.assertEquals(64, digest.length); // length of digest must be 64: 512bits

    StringBuilder sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        byte j = digest[i];
        int h = j >> 4 & 0x0f;
        int l = j & 0x0f;
        sb.append(Integer.toHexString(h));
        sb.append(Integer.toHexString(l));
    }
    String result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        sb.append(String.format("%02x", new Integer(digest[i] & 0xff)));
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    sb = new StringBuilder(32);
    for (int i = 0; i < digest.length; i++) {
        int j = digest[i];
        if(digest[i] < 0) {
            j = 256 + digest[i];
        }
        sb.append(HEX_CHAR[j / 16]);
        sb.append(HEX_CHAR[j % 16]);
    }
    result = sb.toString();
    System.out.println(message + "(hex:" + result + ")");

    result = Base64.byteArrayToBase64(digest);
    System.out.println(message + "(base64:" + result + ")");
}

Using HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-512 with IPsec, https://tools.ietf.org/html/rfc4868

A 224-bit One-way Hash Function: SHA-224, https://tools.ietf.org/html/rfc3874

US Secure Hash Algorithms (SHA and SHA-based HMAC and HKDF), https://tools.ietf.org/html/rfc6234

US Secure Hash Algorithms (SHA and HMAC-SHA), https://tools.ietf.org/html/rfc4634

US Secure Hash Algorithm 1 (SHA1), https://tools.ietf.org/html/rfc3174

Collision_Search_Attacks_on_SHA1.pdf (48.1 KB)
下载次数: 6

Collisions_for_Hash_Functions_MD4__MD5__HAVAL-128_and_RIPEMD__.pdf (56.2 KB)
下载次数: 6

Finding_Collisions_in_the_Full_SHA-1.pdf (212.3 KB)
下载次数: 4

How_to_Break_MD5_and_Other_Hash_Functions.pdf (184.9 KB)
下载次数: 5

collision.zip (30.7 KB)
下载次数: 6

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storm | 线程安全

2016-09-06 17:07
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