md5.h

纯c md5实现 至少20字 还没到 这回肯定到了

/*
* 带密钥的md5算法库md5lib.h共有下列函数：
* 
* char* MDString (char *); 
* 输入任意一个字符串，经过md5运算后，返回32个字符长的字符串
*
* char* MDFile (char *); 
* 输入任意一个文件名，文件内容经过md5运算后，返回32个字符长的字符串
*
* char* hmac_md5(char* text, char* key); 
* 输入任意一个字符串text,和一个用做密钥的字符串key,
* 经过hmac_md5算法处理，返回处理结果：一个定长字符串（32个字符）
*/

/* MD5lib.h - md5 library
*
* Copyright (C) 1990-2, RSA Data Security, Inc. Created 1990. All 
* rights reserved.

* RSA Data Security, Inc. makes no representations concerning either 
* the merchantability of this software or the suitability of this 
* software for any particular purpose. It is provided "as is" 
* without express or implied warranty of any kind.

* These notices must be retained in any copies of any part of this 
* documentation and/or software.

* The following makes MD default to MD5 if it has not already been 
* defined with C compiler flags. 
*/
#include <stdio.h>
#include <time.h>
#include <string.h>

#define MD 5

/* GLOBAL.H - RSAREF types and constants

* PROTOTYPES should be set to one if and only if the compiler supports
* function argument prototyping.
* The following makes PROTOTYPES default to 0 if it has not already
* been defined with C compiler flags. 
*/

#ifndef PROTOTYPES
#define PROTOTYPES 1
#endif

typedef unsigned char *POINTER; /* POINTER defines a generic pointer type */
typedef unsigned short int UINT2; /* UINT2 defines a two byte word */
typedef unsigned long int UINT4; /* UINT4 defines a four byte word */

/* PROTO_LIST is defined depending on how PROTOTYPES is defined above.
If using PROTOTYPES, then PROTO_LIST returns the list, otherwise it returns an empty list. */

#if PROTOTYPES
#define PROTO_LIST(list) list
#else
#define PROTO_LIST(list) ()
#endif

/* Length of test block, number of test blocks. */
#define TEST_BLOCK_LEN 1000
#define TEST_BLOCK_COUNT 1000

/* Constants for MD5Transform routine. */
#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

char* MDString PROTO_LIST ((char *));
char* MDFile PROTO_LIST ((char *));
char* hmac_md5(char* text, char* key);

typedef struct {
UINT4 state[4];    /* state (ABCD) */
UINT4 count[2];        /* number of bits, modulo 2^64 (lsb first) */
unsigned char buffer[64]; /* input buffer */
} MD5_CTX;

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
};

/* F, G, H and I are basic MD5 functions. */
#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)))

/* ROTATE_LEFT rotates x left n bits. */
#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
Rotation is separate from addition to prevent recomputation. */
#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); \
}

void MD5Init (MD5_CTX *context);
void MD5Update(MD5_CTX *context, unsigned char *input,unsigned int inputLen);

void MD5Final (unsigned char digest[16], MD5_CTX *context);
static void MD5Transform (UINT4 [4], unsigned char [64]) ;
static void Encode(unsigned char *, UINT4 *, unsigned int);
static void Decode (UINT4 *, unsigned char *, unsigned int);
static void MD5_memcpy(POINTER, POINTER, unsigned int);
static void MD5_memset(POINTER, int, unsigned int);

/* MD5 initialization. Begins an MD5 operation, writing a new context. */
void MD5Init (MD5_CTX *context) /* context */
{
context->count[0] = context->count[1] = 0;
/* Load magic initialization constants. */
context->state[0] = 0x67452301;
context->state[1] = 0xefcdab89;
context->state[2] = 0x98badcfe;
context->state[3] = 0x10325476;
}

/* MD5 block update operation. Continues an MD5 message-digest
operation, processing another message block, and updating the context. */
void MD5Update (MD5_CTX *context, unsigned char *input, unsigned int inputLen)
     /* context */ /* input block */ /* length of input block */
{
unsigned int i, index, partLen;

/* Compute number of bytes mod 64 */
index = (unsigned int)((context->count[0] >> 3) & 0x3F);

/* Update number of bits */
if ((context->count[0] += ((UINT4)inputLen << 3)) < ((UINT4)inputLen << 3))
   context->count[1]++;
context->count[1] += ((UINT4)inputLen >> 29);

partLen = 64 - index;

/* Transform as many times as possible. */
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;

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

/* MD5 finalization. Ends an MD5 message-digest operation, writing the
the message digest and zeroizing the context. */
void MD5Final (unsigned char digest[16], MD5_CTX *context)
     /* message digest */ /* context */
{
unsigned char bits[8];
unsigned int index, padLen;

/* Save number of bits */
Encode (bits, context->count, 8);

/* Pad out to 56 mod 64.*/
index = (unsigned int)((context->count[0] >> 3) & 0x3f);
padLen = (index < 56) ? (56 - index) : (120 - index);
MD5Update (context,(unsigned char*) PADDING, padLen);

/* Append length (before padding) */
MD5Update (context, bits, 8);
/* Store state in digest */
Encode (digest, context->state, 16);

/* Zeroize sensitive information.*/
MD5_memset ((POINTER)context, 0, sizeof (*context));
}

/* MD5 basic transformation. Transforms state based on block. */
static void MD5Transform (UINT4 state[4], unsigned char block[64])
{
int i=0;
UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
Decode (x, block, 64);

/* Round 1 */
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 */

/* Round 2 */
GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */