#include "f_md5.h"
#include <string.h>


unsigned char PADDING[]={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};  
  
void f_md5_init(MD5_CTX *context)  
{  
    context->count[0] = 0;  
    context->count[1] = 0;  
    context->state[0] = 0x67452301;  
    context->state[1] = 0xEFCDAB89;  
    context->state[2] = 0x98BADCFE;  
    context->state[3] = 0x10325476;  
}  
void f_md5_update(MD5_CTX *context,unsigned char *input,unsigned int inputlen)  
{  
    unsigned int i = 0,index = 0,partlen = 0;  
    index = (context->count[0] >> 3) & 0x3F;  
    partlen = 64 - index;  
    context->count[0] += inputlen << 3;  
    if(context->count[0] < (inputlen << 3))  
        context->count[1]++;  
    context->count[1] += inputlen >> 29;  
  
    if(inputlen >= partlen)  
    {  
        memcpy(&context->buffer[index],input,partlen);  
        f_md5_transform(context->state,context->buffer);  
        for(i = partlen;i+64 <= inputlen;i+=64)  
            f_md5_transform(context->state,&input[i]);  
        index = 0;          
    }    
    else  
    {  
        i = 0;  
    }  
    memcpy(&context->buffer[index],&input[i],inputlen-i);  
}  
void f_md5_final(MD5_CTX *context,unsigned char digest[16])  
{  
    unsigned int index = 0,padlen = 0;  
    unsigned char bits[8];  
    index = (context->count[0] >> 3) & 0x3F;  
    padlen = (index < 56)?(56-index):(120-index);  
    f_md5_encode(bits,context->count,8);  
    f_md5_update(context,PADDING,padlen);  
    f_md5_update(context,bits,8);  
    f_md5_encode(digest,context->state,16);  
}  
void f_md5_encode(unsigned char *output,unsigned int *input,unsigned int len)  
{  
    unsigned int i = 0,j = 0;  
    while(j < len)  
    {  
        output[j] = input[i] & 0xFF;    
        output[j+1] = (input[i] >> 8) & 0xFF;  
        output[j+2] = (input[i] >> 16) & 0xFF;  
        output[j+3] = (input[i] >> 24) & 0xFF;  
        i++;  
        j+=4;  
    }  
}  
void f_md5_decode(unsigned int *output,unsigned char *input,unsigned int len)  
{  
    unsigned int i = 0,j = 0;  
    while(j < len)  
    {  
        output[i] = (input[j]) |  
            (input[j+1] << 8) |  
            (input[j+2] << 16) |  
            (input[j+3] << 24);  
        i++;  
        j+=4;   
    }  
}  
void f_md5_transform(unsigned int state[4],unsigned char block[64])  
{  
    unsigned int a = state[0];  
    unsigned int b = state[1];  
    unsigned int c = state[2];  
    unsigned int d = state[3];  
    unsigned int x[64];  
    f_md5_decode(x,block,64);  
    FF(a, b, c, d, x[ 0], 7, 0xd76aa478);   
    FF(d, a, b, c, x[ 1], 12, 0xe8c7b756);   
    FF(c, d, a, b, x[ 2], 17, 0x242070db);   
    FF(b, c, d, a, x[ 3], 22, 0xc1bdceee);   
    FF(a, b, c, d, x[ 4], 7, 0xf57c0faf);   
    FF(d, a, b, c, x[ 5], 12, 0x4787c62a);   
    FF(c, d, a, b, x[ 6], 17, 0xa8304613);   
    FF(b, c, d, a, x[ 7], 22, 0xfd469501);   
    FF(a, b, c, d, x[ 8], 7, 0x698098d8);   
    FF(d, a, b, c, x[ 9], 12, 0x8b44f7af);   
    FF(c, d, a, b, x[10], 17, 0xffff5bb1);   
    FF(b, c, d, a, x[11], 22, 0x895cd7be);   
    FF(a, b, c, d, x[12], 7, 0x6b901122);   
    FF(d, a, b, c, x[13], 12, 0xfd987193);   
    FF(c, d, a, b, x[14], 17, 0xa679438e);   
    FF(b, c, d, a, x[15], 22, 0x49b40821);   
  
      
    GG(a, b, c, d, x[ 1], 5, 0xf61e2562);   
    GG(d, a, b, c, x[ 6], 9, 0xc040b340);   
    GG(c, d, a, b, x[11], 14, 0x265e5a51);   
    GG(b, c, d, a, x[ 0], 20, 0xe9b6c7aa);   
    GG(a, b, c, d, x[ 5], 5, 0xd62f105d);   
    GG(d, a, b, c, x[10], 9,  0x2441453);   
    GG(c, d, a, b, x[15], 14, 0xd8a1e681);   
    GG(b, c, d, a, x[ 4], 20, 0xe7d3fbc8);   
    GG(a, b, c, d, x[ 9], 5, 0x21e1cde6);   
    GG(d, a, b, c, x[14], 9, 0xc33707d6);   
    GG(c, d, a, b, x[ 3], 14, 0xf4d50d87);   
    GG(b, c, d, a, x[ 8], 20, 0x455a14ed);   
    GG(a, b, c, d, x[13], 5, 0xa9e3e905);   
    GG(d, a, b, c, x[ 2], 9, 0xfcefa3f8);   
    GG(c, d, a, b, x[ 7], 14, 0x676f02d9);   
    GG(b, c, d, a, x[12], 20, 0x8d2a4c8a);   
  
      
    HH(a, b, c, d, x[ 5], 4, 0xfffa3942);   
    HH(d, a, b, c, x[ 8], 11, 0x8771f681);   
    HH(c, d, a, b, x[11], 16, 0x6d9d6122);   
    HH(b, c, d, a, x[14], 23, 0xfde5380c);   
    HH(a, b, c, d, x[ 1], 4, 0xa4beea44);   
    HH(d, a, b, c, x[ 4], 11, 0x4bdecfa9);   
    HH(c, d, a, b, x[ 7], 16, 0xf6bb4b60);   
    HH(b, c, d, a, x[10], 23, 0xbebfbc70);   
    HH(a, b, c, d, x[13], 4, 0x289b7ec6);   
    HH(d, a, b, c, x[ 0], 11, 0xeaa127fa);   
    HH(c, d, a, b, x[ 3], 16, 0xd4ef3085);   
    HH(b, c, d, a, x[ 6], 23,  0x4881d05);   
    HH(a, b, c, d, x[ 9], 4, 0xd9d4d039);   
    HH(d, a, b, c, x[12], 11, 0xe6db99e5);   
    HH(c, d, a, b, x[15], 16, 0x1fa27cf8);   
    HH(b, c, d, a, x[ 2], 23, 0xc4ac5665);   
  
      
    II(a, b, c, d, x[ 0], 6, 0xf4292244);   
    II(d, a, b, c, x[ 7], 10, 0x432aff97);   
    II(c, d, a, b, x[14], 15, 0xab9423a7);   
    II(b, c, d, a, x[ 5], 21, 0xfc93a039);   
    II(a, b, c, d, x[12], 6, 0x655b59c3);   
    II(d, a, b, c, x[ 3], 10, 0x8f0ccc92);   
    II(c, d, a, b, x[10], 15, 0xffeff47d);   
    II(b, c, d, a, x[ 1], 21, 0x85845dd1);   
    II(a, b, c, d, x[ 8], 6, 0x6fa87e4f);   
    II(d, a, b, c, x[15], 10, 0xfe2ce6e0);   
    II(c, d, a, b, x[ 6], 15, 0xa3014314);   
    II(b, c, d, a, x[13], 21, 0x4e0811a1);   
    II(a, b, c, d, x[ 4], 6, 0xf7537e82);   
    II(d, a, b, c, x[11], 10, 0xbd3af235);   
    II(c, d, a, b, x[ 2], 15, 0x2ad7d2bb);   
    II(b, c, d, a, x[ 9], 21, 0xeb86d391);   
    state[0] += a;  
    state[1] += b;  
    state[2] += c;  
    state[3] += d;  
}