我想问几个关于MD5加密的问题

skice · 发表于 2004-11-15 20:13:00

实在看不懂标准上那串长长的C程序，所以只能在这里问了

1、两个DWORD相加的话，如果超过DWORD的最大值0xFFFF FFFF，要做什么处理么？RFC上好象就是简单的用+表示，是不是只要按C/C++默认的就行了？
2、关于补位之后最后加一个64位的“长度”信息，单位是字节还是字？
3、将最后a，b，c，d输出是什么顺序？就像这样 printf("%x%x%x%x", a, b, c, d)还是要做高低位的对调？

郁闷了好久了，就是得不到标准的答案！

binfen20 · 发表于 2004-11-15 21:57:00

你把源码贴上来，再看看

Civilian · 发表于 2004-11-15 22:49:00

大家试试idea 据说还没有被破解过
下载pgp的代码，里面有

skice · 发表于 2004-11-19 17:35:00

//函数定义
#define df(x, y, z) (((x)&(y))|((~(x))&(z)))
#define dg(x, y, z) (((x)&(z))|((y)&(~(z))))
#define dh(x, y, z) ((x)^(y)^(z))
#define di(x, y, z) ((y)^((x)|(~(z))))

DWORD RotateLeft(DWORD x, CHAR o)
{
return ((x << o) | (x >> (32 - o)));
}

void ff(DWORD &a, DWORD b, DWORD c, DWORD d, DWORD m, CHAR o, DWORD t)
{
a += df(b, c, d) + m + t;
a = RotateLeft(a, o);
a += b;
}

void gg(DWORD &a, DWORD b, DWORD c, DWORD d, DWORD m, CHAR o, DWORD t)
{
a += dg(b, c, d) + m + t;
a = RotateLeft(a, o);
a += b;
}

void hh(DWORD &a, DWORD b, DWORD c, DWORD d, DWORD m, CHAR o, DWORD t)
{
a += dh(b, c, d) + m + t;
a = RotateLeft(a, o);
a += b;
}

void ii(DWORD &a, DWORD b, DWORD c, DWORD d, DWORD m, CHAR o, DWORD t)
{
a += di(b, c, d) + m + t;
a = RotateLeft(a, o);
a += b;
}

//主程序
DWORD i, j;
BYTE *Data;
DWORD oLen, nLen;
DWORD m[16];

UpdateData();
oLen = m_Source.GetLength();
nLen = ((oLen + 8) / 64 + 1) * 64;

Data = new BYTE[nLen];
LPTSTR s = m_Source.GetBuffer(oLen);
memcpy(Data, s, oLen);
s = NULL;
m_Source.ReleaseBuffer();
for (i = oLen; i < nLen - 8; i++)
Data = 0;
if (oLen != nLen - 8)
Data[oLen] = 128;
ULONGLONG l = oLen;
Data[nLen - 1] = (BYTE)(l & 0xFF);
Data[nLen - 2] = (BYTE)((l >> 8) & 0xFF);
Data[nLen - 3] = (BYTE)((l >> 16) & 0xFF);
Data[nLen - 4] = (BYTE)((l >> 24) & 0xFF);
Data[nLen - 5] = (BYTE)((l >> 32) & 0xFF);
Data[nLen - 6] = (BYTE)((l >> 40) & 0xFF);
Data[nLen - 7] = (BYTE)((l >> 48) & 0xFF);
Data[nLen - 8] = (BYTE)((l >> 56) & 0xFF);

DWORD bA = 0x67452301;
DWORD bB = 0xefcdab89;
DWORD bC = 0x98badcfe;
DWORD bD = 0x10325476;
DWORD a, b, c, d;

for (i = 0; i < nLen / 64; i++)
{
a = bA; b = bB; c = bC; d = bD;
for (j = 0; j < 16; j++)
{
m[j] = (Data[i * 64 + j * 4] << 24) + (Data[i * 64 + j * 4 + 1] << 16)
+ (Data[i * 64 + j * 4 + 2] << 8) + Data[i * 64 + j * 4 + 3];
}

ff(a, b, c, d, m[ 0],  7, 0xd76aa478);
ff(d, a, b, c, m[ 1], 12, 0xe8c7b756);
ff(c, d, a, b, m[ 2], 17, 0x242070db);
ff(b, c, d, a, m[ 3], 22, 0xc1bdceee);
ff(a, b, c, d, m[ 4],  7, 0xf57c0faf);
ff(d, a, b, c, m[ 5], 12, 0x4787c62a);
ff(c, d, a, b, m[ 6], 17, 0xa8304613);
ff(b, c, d, a, m[ 7], 22, 0xfd469501);
ff(a, b, c, d, m[ 8],  7, 0x698098d8);
ff(d, a, b, c, m[ 9], 12, 0x8b44f7af);
ff(c, d, a, b, m[10], 17, 0xffff5bb1);
ff(b, c, d, a, m[11], 22, 0x895cd7be);
ff(a, b, c, d, m[12],  7, 0x6b901122);
ff(d, a, b, c, m[13], 12, 0xfd987193);
ff(c, d, a, b, m[14], 17, 0xa679438e);
ff(b, c, d, a, m[15], 22, 0x49b40821);

gg(a, b, c, d, m[ 1],  5, 0xf61e2562);
gg(d, a, b, c, m[ 6],  9, 0xc040b340);
gg(c, d, a, b, m[11], 14, 0x265e5a51);
gg(b, c, d, a, m[ 0], 20, 0xe9b6c7aa);
gg(a, b, c, d, m[ 5],  5, 0xd62f105d);
gg(d, a, b, c, m[10],  9, 0x02441453);
gg(c, d, a, b, m[15], 14, 0xd8a1e681);
gg(b, c, d, a, m[ 4], 20, 0xe7d3fbc8);
gg(a, b, c, d, m[ 9],  5, 0x21e1cde6);
gg(d, a, b, c, m[14],  9, 0xc33707d6);
gg(c, d, a, b, m[ 3], 14, 0xf4d50d87);
gg(b, c, d, a, m[ 8], 20, 0x455a14ed);
gg(a, b, c, d, m[13],  5, 0xa9e3e905);
gg(d, a, b, c, m[ 2],  9, 0xfcefa3f8);
gg(c, d, a, b, m[ 7], 14, 0x676f02d9);
gg(b, c, d, a, m[12], 20, 0x8d2a4c8a);

hh(a, b, c, d, m[ 5],  4, 0xfffa3942);
hh(d, a, b, c, m[ 8], 11, 0x8771f681);
hh(c, d, a, b, m[11], 16, 0x6d9d6122);
hh(b, c, d, a, m[14], 23, 0xfde5380c);
hh(a, b, c, d, m[ 1],  4, 0xa4beea44);
hh(d, a, b, c, m[ 4], 11, 0x4bdecfa9);
hh(c, d, a, b, m[ 7], 16, 0xf6bb4b60);
hh(b, c, d, a, m[10], 23, 0xbebfbc70);
hh(a, b, c, d, m[13],  4, 0x289b7ec6);
hh(d, a, b, c, m[ 0], 11, 0xeaa127fa);
hh(c, d, a, b, m[ 3], 16, 0xd4ef3085);
hh(b, c, d, a, m[ 6], 23, 0x04881d05);
hh(a, b, c, d, m[ 9],  4, 0xd9d4d039);
hh(d, a, b, c, m[12], 11, 0xe6db99e5);
hh(c, d, a, b, m[15], 16, 0x1fa27cf8);
hh(b, c, d, a, m[ 2], 23, 0xc4ac5665);

ii(a, b, c, d, m[ 0],  6, 0xf4292244);
ii(d, a, b, c, m[ 7], 10, 0x432aff97);
ii(c, d, a, b, m[14], 15, 0xab9423a7);
ii(b, c, d, a, m[ 5], 21, 0xfc93a039);
ii(a, b, c, d, m[12],  6, 0x655b59c3);
ii(d, a, b, c, m[ 3], 10, 0x8f0ccc92);
ii(c, d, a, b, m[10], 15, 0xffeff47d);
ii(b, c, d, a, m[ 1], 21, 0x85845dd1);
ii(a, b, c, d, m[ 8],  6, 0x6fa87e4f);
ii(d, a, b, c, m[15], 10, 0xfe2ce6e0);
ii(c, d, a, b, m[ 6], 15, 0xa3014314);
ii(b, c, d, a, m[13], 21, 0x4e0811a1);
ii(a, b, c, d, m[ 4],  6, 0xf7537e82);
ii(d, a, b, c, m[11], 10, 0xbd3af235);
ii(c, d, a, b, m[ 2], 15, 0x2ad7d2bb);
ii(b, c, d, a, m[ 9], 21, 0xeb86d391);

bA += a; bB += b; bC += c; bD += d;
}

delete [] Data;

m_Dest.Format("%x%x%x%x", bA, bB, bC, bD);
UpdateData(FALSE);

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我想问几个关于MD5加密的问题

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Re:我想问几个关于MD5加密的问题

Re:我想问几个关于MD5加密的问题