整理的一点MD5资料(第一部分)

MD5加密算法研究

MD5简介:

MD5
的全称是Message-Digest Algorithm 5,在90年代初由MIT的计算机科学实验室和RSA Data Security Inc发明,经MD2MD3MD4发展而来。

Message-Digest
泛指字节串(Message)Hash变换,就是把一个任意长度的字节串变换成一定长的大整数。请注意我使用了字节串而不是字符串这个词,是因为这种变换只与字节的值有关,与字符集或编码方式无关。

MD5
将任意长度的字节串变换成一个128bit的大整数,并且它是一个不可逆的字符串变换算法,换句话说就是,即使你看到源程序和算法描述,也无法将一个MD5的值变换回原始的字符串,从数学原理上说,是因为原始的字符串有无穷多个,这有点象不存在反函数的数学函数。

MD5
的典型应用是对一段Message(字节串)产生fingerprint(指纹),以防止被篡改。举个例子,你将一段话写在一个叫readme.txt文件中,并对这个readme.txt产生一个MD5的值并记录在案,然后你可以传播这个文件给别人,别人如果修改了文件中的任何内容,你对这个文件重新计算MD5时就会发现。如果再有一个第三方的认证机构,用MD5还可以防止文件作者的抵赖,这就是所谓的数字签名应用。

MD5
还广泛用于加密和解密技术上,在很多操作系统中,用户的密码是以MD5值(或类似的其它算法)的方式保存的, 用户Login的时候,系统是把用户输入的密码计算成MD5值,然后再去和系统中保存的MD5值进行比较,而系统并不知道用户的密码是什么。

一些黑客破获这种密码的方法是一种被称为跑字典的方法。有两种方法得到字典,一种是日常搜集的用做密码的字符串表,另一种是用排列组合方法生成的,先用MD5程序计算出这些字典项的MD5值,然后再用目标的MD5值在这个字典中检索。

即使假设密码的最大长度为8,同时密码只能是字母和数字,共26+26+10=62个字符,排列组合出的字典的项数则是P(62,1)+P(62,2)….+P(62,8),那也已经是一个很天文的数字了,存储这个字典就需要TB级的磁盘组,而且这种方法还有一个前提,就是能获得目标账户的密码MD5值的情况下才可以。

在软件的加密保护中 很多软件采用MD5保护  但是由于MD5算法为不可逆算法 所以所有的软件都是使用MD5算法作为一个加密的中间步骤,比如对用户名做一个MD5变换,结果再进行一个可逆的加密变换,做注册机时也只要先用MD5变换,然后再用一个逆算法。所以对于破解者来说只要能看出是MD5就很容易了。

MD5
代码的特点明显,跟踪时很容易发现,如果软件采用MD5算法,在数据初始化的时候必然用到以下的四个常数
0x67452301;
0xefcdab89;
0x98badcfe;
0x10325476;
若常数不等 则可能是变形的MD5算法 或者根本就不是这个算法。在内存了也就是
01 23 45 67 89 ab cd ef fe dc ......32 10    16
个字节
————————————————————————————————————————————

MD5
算法:

第一步:增加填充
增加padding使得数据长度(bit为单位)模512448。如果数据长度正好是模512448,增加512个填充bit,也就是说填充的个数为1-512。第一个bit1,其余全部为0
第二步:补足长度
将数据长度转换为64bit的数值,如果长度超过64bit所能表示的数据长度的范围,值保留最后64bit,增加到前面填充的数据后面,使得最后的数据为512bit的整数倍。也就是32bit16倍的整数倍。在RFC1321中,32bit称为一个word
第三步:初始化变量:
用到4个变量,分别为ABCD,均为32bit长。初始化为:
A: 01 23 45 67
B: 89 ab cd ef
C: fe dc ba 98
D: 76 54 32 10
第四步:数据处理:
首先定义4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))
其中:XY表示按位与,X v Y表示按位或,not(X)表示按位取反。xor表示按位异或。
函数中的XYZ均为32bit

定义一个需要用到的数组:T(i),i取值1-64,T(i)等于abs(sin(i))4294967296倍的整数部分,i为弧度。
假设前三步处理后的数据长度为32*16*Nbit

第五步:输出:
最后得到的ABCD为输出结果,共128bitA为低位,D为高位。





MD5
在编程中的实现


下面来看看如何在C语言和VB中实现MD5算法
————————————————————————————————————————————

*/
#ifndef PROTOTYPES
#define PROTOTYPES 0
#endif
typedef unsigned char *POINTER;
typedef unsigned short int UINT2;
typedef unsigned long int UINT4;
#if PROTOTYPES
#define PROTO_LIST(list) list
#else
#define PROTO_LIST(list) ()
#endif

—————————— MD5.h————————————————————————————

typedef struct {
  UINT4 state[4];       
  UINT4 count[2];     
  unsigned char buffer[64];                     
} MD5_CTX;

void MD5Init PROTO_LIST ((MD5_CTX *));
void MD5Update PROTO_LIST
  ((MD5_CTX *, unsigned char *, unsigned int));
void MD5Final PROTO_LIST ((unsigned char [16], MD5_CTX *));

※※※※※※※※※MD5C.C※※※※※※※※※※※※※※※※※※※※※※※※
i nclude "global.h"
i nclude "md5.h"
#define S11 7
#define S12 12
#define S13 17
#define S14 22
#define S21 5
#define S22 9
#define S23 14
#define S24 20
#define S31 4
#define S32 11
#define S33 16
#define S34 23
#define S41 6
#define S42 10
#define S43 15
#define S44 21

static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
static void Encode PROTO_LIST
  ((unsigned char *, UINT4 *, unsigned int));
static void Decode PROTO_LIST
  ((UINT4 *, unsigned char *, unsigned int));
static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));

static unsigned char PADDING[64] = {
  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/*
定义F G H I 为四个基数

#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
#define H(x, y, z) ((x) ^ (y) ^ (z))
#define I(x, y, z) ((y) ^ ((x) | (~z)))
#define ROTATE_LEFT(x, n) (((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); \
  }
#define GG(a, b, c, d, x, s, ac) { \
(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
  }
#define HH(a, b, c, d, x, s, ac) { \
(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
  }
#define II(a, b, c, d, x, s, ac) { \
(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
(a) = ROTATE_LEFT ((a), (s)); \
(a) += (b); \
  }

/*
开始进行MD5计算
void MD5Init (context)
MD5_CTX *context;                             
{
  context->count[0] = context->count[1] = 0;
  /*
在这里定义四个常数,也就是我们刚才讲到的四个特征数.

  context->state[0] = 0x67452301;
  context->state[1] = 0xefcdab89;
  context->state[2] = 0x98badcfe;
  context->state[3] = 0x10325476;
}

void MD5Update (context, input, inputLen)
MD5_CTX *context;                               
unsigned char *input;                           
unsigned int inputLen;                 
{
  unsigned int i, index, partLen;

  index = (unsigned int)((context->count[0] >> 3) & 0x3F);

  if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
context->count[1]++;
  context->count[1] += ((UINT4)inputLen >> 29);

  partLen = 64 - index;

  if (inputLen >= partLen) {
MD5_memcpy
  ((POINTER)&context->buffer[index], (POINTER)input, partLen);
MD5Transform (context->state, context->buffer);

for (i = partLen; i + 63 < inputLen; i += 64)
  MD5Transform (context->state, &input[i]);

index = 0;
  }
  else
i = 0;

  MD5_memcpy
((POINTER)&context->buffer[index], (POINTER)&input[i],
  inputLen-i);
}

void MD5Final (digest, context)
unsigned char digest[16];                 
MD5_CTX *context;                             
{
  unsigned char bits[8];
  unsigned int index, padLen;

  Encode (bits, context->count, 8);

  index = (unsigned int)((context->count[0] >> 3) & 0x3f);
  padLen = (index < 56) ? (56 - index) : (120 - index);
  MD5Update (context, PADDING, padLen);
  MD5Update (context, bits, 8);

  Encode (digest, context->state, 16);
  MD5_memset ((POINTER)context, 0, sizeof (*context));
}

static void MD5Transform (state, block)
UINT4 state[4];
unsigned char block[64];
{
  UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];

  Decode (x, block, 64);

  /*
第一轮循环 */
  FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
  FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
  FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
  FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
  FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
  FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
  FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
  FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
  FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
  FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
  FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
  FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
  FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
  FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
  FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
  FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */

/*
第二轮循环 */
  GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
  GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
  GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
  GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
  GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
  GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
  GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
  GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
  GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
  GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
  GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
  GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
  GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
  GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
  GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
  GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */

  /*
第三轮循环 */
  HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
  HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
  HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
  HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
  HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
  HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
  HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
  HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
  HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
  HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
  HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
  HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
  HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
  HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
  HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
  HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */

  /*
第四轮循环 */
  II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
  II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
  II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
  II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
  II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
  II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
  II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
  II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
  II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
  II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
  II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
  II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
  II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
  II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
  II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
  II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */

  state[0] += a;
  state[1] += b;
  state[2] += c;
  state[3] += d;

  MD5_memset ((POINTER)x, 0, sizeof (x));

}
static void Encode (output, input, len)
unsigned char *output;
UINT4 *input;
unsigned int len;
{
  unsigned int i, j;

  for (i = 0, j = 0; j < len; i++, j += 4) {
output[j] = (unsigned char)(input[i] & 0xff);
output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
  }
}

static void Decode (output, input, len)
UINT4 *output;
unsigned char *input;
unsigned int len;
{
  unsigned int i, j;

  for (i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
  (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
}

static void MD5_memcpy (output, input, len)
POINTER output;
POINTER input;
unsigned int len;
{
  unsigned int i;

  for (i = 0; i < len; i++) output[i] = input[i];
}

static void MD5_memset (output, value, len)
POINTER output;
int value;
unsigned int len;
{
  unsigned int i;

  for (i = 0; i < len; i++)
((char *)output)[i] = (char)value;
}
————————————————C
代码结束——————————


VB中实现MD5算法
——————————————————————————————————————————
Option Explicit

Dim w1 As String, w2 As String, w3 As String, w4 As String

Function MD5F(ByVal tempstr As String, ByVal w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
MD5F = BigMod32Add(RotLeft(BigMod32Add(BigMod32Add(w, tempstr), BigMod32Add(Xin, qdata)), rots), X)
End Function

Sub MD5F1(w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
Dim tempstr As String

    tempstr = BigXOR(z, BigAND(X, BigXOR(y, z)))
    w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Sub MD5F2(w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
Dim tempstr As String

    tempstr = BigXOR(y, BigAND(z, BigXOR(X, y)))
    w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Sub MD5F3(w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
Dim tempstr As String

    tempstr = BigXOR(X, BigXOR(y, z))
    w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Sub MD5F4(w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
Dim tempstr As String

    tempstr = BigXOR(y, BigOR(X, BigNOT(z)))
    w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Function MD5_Calc(ByVal hashthis As String) As String
ReDim buf(0 To 3) As String
ReDim Xin(0 To 15) As String
Dim tempnum As Integer, tempnum2 As Integer, loopit As Integer, loopouter As Integer, loopinner As Integer
Dim a As String, b As String, c As String, d As String

    tempnum = 8 * Len(hashthis)
    hashthis = hashthis + Chr$(128) 'Add binary 10000000
    tempnum2 = 56 - Len(hashthis) Mod 64

    If tempnum2 < 0 Then
        tempnum2 = 64 + tempnum2
    End If

    hashthis = hashthis + String$(tempnum2, Chr$(0))

    For loopit = 1 To 8
        hashthis = hashthis + Chr$(tempnum Mod 256)
        tempnum = tempnum - tempnum Mod 256
        tempnum = tempnum / 256
    Next loopit

   
    buf(0) = "67452301"
    buf(1) = "efcdab89"
    buf(2) = "98badcfe"
    buf(3) = "10325476"

   
For loopouter = 0 To Len(hashthis) / 64 - 1
        a = buf(0)
        b = buf(1)
        c = buf(2)
        d = buf(3)

        ' Get the 512 bits
        For loopit = 0 To 15
            Xin(loopit) = ""
            For loopinner = 1 To 4
                Xin(loopit) = Hex$(Asc(Mid$(hashthis, 64 * loopouter + 4 * loopit + loopinner, 1))) + Xin(loopit)
                If Len(Xin(loopit)) Mod 2 Then Xin(loopit) = "0" + Xin(loopit)
            Next loopinner
        Next loopit

       

' 第一轮循环
        MD5F1 a, b, c, d, Xin(0), "d76aa478", 7
        MD5F1 d, a, b, c, Xin(1), "e8c7b756", 12
        MD5F1 c, d, a, b, Xin(2), "242070db", 17
        MD5F1 b, c, d, a, Xin(3), "c1bdceee", 22
        MD5F1 a, b, c, d, Xin(4), "f57c0faf", 7
        MD5F1 d, a, b, c, Xin(5), "4787c62a", 12
        MD5F1 c, d, a, b, Xin(6), "a8304613", 17
        MD5F1 b, c, d, a, Xin(7), "fd469501", 22
        MD5F1 a, b, c, d, Xin(8), "698098d8", 7
        MD5F1 d, a, b, c, Xin(9), "8b44f7af", 12
        MD5F1 c, d, a, b, Xin(10), "ffff5bb1", 17
        MD5F1 b, c, d, a, Xin(11), "895cd7be", 22
        MD5F1 a, b, c, d, Xin(12), "6b901122", 7
        MD5F1 d, a, b, c, Xin(13), "fd987193", 12
        MD5F1 c, d, a, b, Xin(14), "a679438e", 17
        MD5F1 b, c, d, a, Xin(15), "49b40821", 22

        '
第二轮循环
        MD5F2 a, b, c, d, Xin(1), "f61e2562", 5
        MD5F2 d, a, b, c, Xin(6), "c040b340", 9
        MD5F2 c, d, a, b, Xin(11), "265e5a51", 14
        MD5F2 b, c, d, a, Xin(0), "e9b6c7aa", 20
        MD5F2 a, b, c, d, Xin(5), "d62f105d", 5
        MD5F2 d, a, b, c, Xin(10), "02441453", 9
        MD5F2 c, d, a, b, Xin(15), "d8a1e681", 14
        MD5F2 b, c, d, a, Xin(4), "e7d3fbc8", 20
        MD5F2 a, b, c, d, Xin(9), "21e1cde6", 5
        MD5F2 d, a, b, c, Xin(14), "c33707d6", 9
        MD5F2 c, d, a, b, Xin(3), "f4d50d87", 14
        MD5F2 b, c, d, a, Xin(8), "455a14ed", 20
        MD5F2 a, b, c, d, Xin(13), "a9e3e905", 5
        MD5F2 d, a, b, c, Xin(2), "fcefa3f8", 9
        MD5F2 c, d, a, b, Xin(7), "676f02d9", 14
        MD5F2 b, c, d, a, Xin(12), "8d2a4c8a", 20

        '
第三轮循环
        MD5F3 a, b, c, d, Xin(5), "fffa3942", 4
        MD5F3 d, a, b, c, Xin(8), "8771f681", 11
        MD5F3 c, d, a, b, Xin(11), "6d9d6122", 16
        MD5F3 b, c, d, a, Xin(14), "fde5380c", 23
        MD5F3 a, b, c, d, Xin(1), "a4beea44", 4
        MD5F3 d, a, b, c, Xin(4), "4bdecfa9", 11
        MD5F3 c, d, a, b, Xin(7), "f6bb4b60", 16
        MD5F3 b, c, d, a, Xin(10), "bebfbc70", 23
        MD5F3 a, b, c, d, Xin(13), "289b7ec6", 4
        MD5F3 d, a, b, c, Xin(0), "e27fa", 11
        MD5F3 c, d, a, b, Xin(3), "d4ef3085", 16
        MD5F3 b, c, d, a, Xin(6), "04881d05", 23
        MD5F3 a, b, c, d, Xin(9), "d9d4d039", 4
        MD5F3 d, a, b, c, Xin(12), "e6db99e5", 11
        MD5F3 c, d, a, b, Xin(15), "1fa27cf8", 16
        MD5F3 b, c, d, a, Xin(2), "c4ac5665", 23

        '
第四轮循环
        MD5F4 a, b, c, d, Xin(0), "f4292244", 6
        MD5F4 d, a, b, c, Xin(7), "432aff97", 10
        MD5F4 c, d, a, b, Xin(14), "ab9423a7", 15
        MD5F4 b, c, d, a, Xin(5), "fc93a039", 21
        MD5F4 a, b, c, d, Xin(12), "655b59c3", 6
        MD5F4 d, a, b, c, Xin(3), "8f0ccc92", 10
        MD5F4 c, d, a, b, Xin(10), "ffeff47d", 15
        MD5F4 b, c, d, a, Xin(1), "85845dd1", 21
        MD5F4 a, b, c, d, Xin(8), "6fa87e4f", 6
        MD5F4 d, a, b, c, Xin(15), "fe2ce6e0", 10
        MD5F4 c, d, a, b, Xin(6), "a3014314", 15
        MD5F4 b, c, d, a, Xin(13), "4e0811a1", 21
        MD5F4 a, b, c, d, Xin(4), "f7537e82", 6
        MD5F4 d, a, b, c, Xin(11), "bd3af235", 10
        MD5F4 c, d, a, b, Xin(2), "2ad7d2bb", 15
        MD5F4 b, c, d, a, Xin(9), "eb86d391", 21

        buf(0) = BigAdd(buf(0), a)
        buf(1) = BigAdd(buf(1), b)
        buf(2) = BigAdd(buf(2), c)
        buf(3) = BigAdd(buf(3), d)
    Next loopouter

    hashthis = ""
    For loopit = 0 To 3
        For loopinner = 3 To 0 Step -1
            hashthis = hashthis + Chr(Val("&H" + Mid$(buf(loopit), 1 + 2 * loopinner, 2)))
        Next loopinner
    Next loopit

MD5_Calc = hashthis
End Function

Function BigMod32Add(ByVal value1 As String, ByVal value2 As String) As String
    BigMod32Add = Right$(BigAdd(value1, value2), 8)
End Function

Public Function BigAdd(ByVal value1 As String, ByVal value2 As String) As String
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

    tempnum = Len(value1) - Len(value2)
    If tempnum < 0 Then
        value1 = Space$(Abs(tempnum)) + value1
    ElseIf tempnum > 0 Then
        value2 = Space$(Abs(tempnum)) + value2
    End If

    tempnum = 0
    For loopit = Len(value1) To 1 Step -1
        tempnum = tempnum + Val("&H" + Mid$(value1, loopit, 1)) + Val("&H" + Mid$(value2, loopit, 1))
        valueans = Hex$(tempnum Mod 16) + valueans
        tempnum = Int(tempnum / 16)
    Next loopit

    If tempnum <> 0 Then
        valueans = Hex$(tempnum) + valueans
    End If

    BigAdd = Right(valueans, 8)
End Function

Public Function RotLeft(ByVal value1 As String, ByVal rots As Integer) As String
Dim tempstr As String
Dim loopit As Integer, loopinner As Integer
Dim tempnum As Integer

    rots = rots Mod 32
   
    If rots = 0 Then
        RotLeft = value1
        Exit Function
    End If

    value1 = Right$(value1, 8)
    tempstr = String$(8 - Len(value1), "0") + value1
    value1 = ""

    '
转换成二进制形式
    For loopit = 1 To 8
        tempnum = Val("&H" + Mid$(tempstr, loopit, 1))
        For loopinner = 3 To 0 Step -1
            If tempnum And 2 ^ loopinner Then
                value1 = value1 + "1"
            Else
                value1 = value1 + "0"
            End If
        Next loopinner
    Next loopit
    tempstr = Mid$(value1, rots + 1) + Left$(value1, rots)

    '
转换为十六进制
    value1 = ""
    For loopit = 0 To 7
        tempnum = 0
        For loopinner = 0 To 3
            If Val(Mid$(tempstr, 4 * loopit + loopinner + 1, 1)) Then

                tempnum = tempnum + 2 ^ (3 - loopinner)
            End If
        Next loopinner
        value1 = value1 + Hex$(tempnum)
    Next loopit

    RotLeft = Right(value1, 8)
End Function

Function BigAND(ByVal value1 As String, ByVal value2 As String) As String
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

    tempnum = Len(value1) - Len(value2)
    If tempnum < 0 Then
        value2 = Mid$(value2, Abs(tempnum) + 1)
    ElseIf tempnum > 0 Then
        value1 = Mid$(value1, tempnum + 1)
    End If

    For loopit = 1 To Len(value1)
        valueans = valueans + Hex$(Val("&H" + Mid$(value1, loopit, 1)) And Val("&H" + Mid$(value2, loopit, 1)))
    Next loopit

    BigAND = valueans
End Function

Function BigNOT(ByVal value1 As String) As String
Dim valueans As String
Dim loopit As Integer

    value1 = Right$(value1, 8)
    value1 = String$(8 - Len(value1), "0") + value1
    For loopit = 1 To 8
        valueans = valueans + Hex$(15 Xor Val("&H" + Mid$(value1, loopit, 1)))
    Next loopit

    BigNOT = valueans
End Function

Function BigOR(ByVal value1 As String, ByVal value2 As String) As String
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

    tempnum = Len(value1) - Len(value2)
    If tempnum < 0 Then
        valueans = Left$(value2, Abs(tempnum))
        value2 = Mid$(value2, Abs(tempnum) + 1)
    ElseIf tempnum > 0 Then
        valueans = Left$(value1, Abs(tempnum))
        value1 = Mid$(value1, tempnum + 1)
    End If

    For loopit = 1 To Len(value1)
        valueans = valueans + Hex$(Val("&H" + Mid$(value1, loopit, 1)) Or Val("&H" + Mid$(value2, loopit, 1)))
    Next loopit

    BigOR = valueans
End Function

Function BigXOR(ByVal value1 As String, ByVal value2 As String) As String
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

    tempnum = Len(value1) - Len(value2)
    If tempnum < 0 Then
        valueans = Left$(value2, Abs(tempnum))
        value2 = Mid$(value2, Abs(tempnum) + 1)
    ElseIf tempnum > 0 Then
        valueans = Left$(value1, Abs(tempnum))
        value1 = Mid$(value1, tempnum + 1)
    End If

    For loopit = 1 To Len(value1)
        valueans = valueans + Hex$(Val("&H" + Mid$(value1, loopit, 1)) Xor Val("&H" + Mid$(value2, loopit, 1)))
    Next loopit

    BigXOR = Right(valueans, 8)
End Function

 

posted on 2007-07-07 16:06  J.D Huang  阅读(295)  评论(0编辑  收藏

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