BitTorrent种子文件的解析+（2）

//sha1.c   info_hash#include <string.h>#include "sha1.h"#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))/* blk0() and blk() perform the initial expand. *//* I got the idea of expanding during the round function from SSLeay */#if (defined(BYTE_ORDER) && BYTE_ORDER==LITTLE_ENDIAN) || (!defined(BYTE_ORDER) && defined(LITTLE_ENDIAN))#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \    |(rol(block->l[i],8)&0x00FF00FF))#else#define blk0(i) block->l[i]#endif#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \    ^block->l[(i+2)&15]^block->l[i&15],1))/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);/* Hash a single 512-bit block. This is the core of the algorithm. */void SHA1Transform(unsigned long state[5], unsigned char buffer[64]){unsigned long a, b, c, d, e;typedef union {    unsigned char c[64];    unsigned long l[16];} CHAR64LONG16;CHAR64LONG16* block;#ifdef SHA1HANDSOFFstatic unsigned char workspace[64];    block = (CHAR64LONG16*)workspace;    memcpy(block, buffer, 64);#else    block = (CHAR64LONG16*)buffer;#endif    /* Copy context->state[] to working vars */    a = state[0];    b = state[1];    c = state[2];    d = state[3];    e = state[4];    /* 4 rounds of 20 operations each. Loop unrolled. */    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);    /* Add the working vars back into context.state[] */    state[0] += a;    state[1] += b;    state[2] += c;    state[3] += d;    state[4] += e;    /* Wipe variables */    a = b = c = d = e = 0;}/* SHA1Init - Initialize new context */void SHA1Init(SHA1_CTX* context){    /* SHA1 initialization constants */    context->state[0] = 0x67452301;    context->state[1] = 0xEFCDAB89;    context->state[2] = 0x98BADCFE;    context->state[3] = 0x10325476;    context->state[4] = 0xC3D2E1F0;    context->count[0] = context->count[1] = 0;}/* Run your data through this. */void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int len){unsigned int i, j;    j = (context->count[0] >> 3) & 63;    if ((context->count[0] += len << 3) < (len << 3)) context->count[1]++;    context->count[1] += (len >> 29);    if ((j + len) > 63) {        memcpy(&context->buffer[j], data, (i = 64-j));        SHA1Transform(context->state, context->buffer);        for ( ; i + 63 < len; i += 64) {            SHA1Transform(context->state, &data[i]);        }        j = 0;    }    else i = 0;    memcpy(&context->buffer[j], &data[i], len - i);}/* Add padding and return the message digest. */void SHA1Final(unsigned char digest[20], SHA1_CTX* context){unsigned long i, j;unsigned char finalcount[8];    for (i = 0; i < 8; i++) {        finalcount[i] = (unsigned char)((context->count[(i >= 4 ? 0 : 1)]         >> ((3-(i & 3)) * 8) ) & 255); /* Endian independent */    }    SHA1Update(context, (unsigned char *)"\200", 1);    while ((context->count[0] & 504) != 448) {        SHA1Update(context, (unsigned char *)"\0", 1);    }    SHA1Update(context, finalcount, 8); /* Should cause a SHA1Transform() */    for (i = 0; i < 20; i++) {        digest[i] = (unsigned char)         ((context->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);    }    /* Wipe variables */    i = j = 0;    memset(context->buffer, 0, 64);    memset(context->state, 0, 20);    memset(context->count, 0, 8);    memset(&finalcount, 0, 8);#ifdef SHA1HANDSOFF /* make SHA1Transform overwrite it's own static vars */    SHA1Transform(context->state, context->buffer);#endif}// sha1.h #ifndef SHA1_H#define SHA1_H/* *    ±ŸÎÄŒþÖеĺ¯ÊýÓÃÓÚ¶ÔÒ»¶ÎÎıŸÊ¹ÓÃsha1Ëã·šŒÆËãÆäHASHÖµ * ±ŸÎÄŒþΪ×ÔÓɵĿª·ÅÔŽŽúÂë,¿ÉÒÔÈÎÒâʹÓÃ,ʵÏÖÏžœÚ²»±ØÀí»á,Ö»ÐèʹÓÃŒŽ¿É */ /*SHA-1 in C   By Steve Reid <[e-mail]>   100% Public DomainTest Vectors (from FIPS PUB 180-1)"abc"A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq"84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1A million repetitions of "a"34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F*/#include <sys/types.h>#define SHA1HANDSOFF#ifdef __cplusplusextern "C" {#endiftypedef struct {    unsigned long state[5];    unsigned long count[2];    unsigned char buffer[64];} SHA1_CTX;void SHA1Transform(unsigned long state[5], unsigned char buffer[64]);void SHA1Init(SHA1_CTX* context);void SHA1Update(SHA1_CTX* context, unsigned char* data, unsigned int len);void SHA1Final(unsigned char digest[20], SHA1_CTX* context);#ifdef __cplusplus}#endif#endif

 






//MAKEFILE 文件
parse_metafile: parse_metafile.o sha1.o
    gcc parse_metafile.o sha1.o -o parse_metafile
parse_metafile.o: parse_metafile.c parse_metafile.h sha1.c sha1.h
sha1.o: sha1.c sha1.h



dtdlut@dtdlut:~/linux_c_language/chapter13/bittorrent$ make
cc    -c -o parse_metafile.o parse_metafile.c
gcc parse_metafile.o sha1.o -o parse_metafile
dtdlut@dtdlut:~/linux_c_language/chapter13/bittorrent$ ./parse_metafile
metafile size is: 493166
http://bt.sdo.com:80/announce
piece length: 262144
get_pieces ok
file_name:AION_setup_0_9_5_0
file_length: 6459043405
info_hash:44 3d 5b 42 65 ef 55 06 5d 0e 58 09 12 d2 39 b7 e8 0f 9e 8a
peer_id -TT1000- 2122544637



结束！
这两天就学了这么点东东，浪费了我一个周六中午才调好，还没睡觉。真崩溃！
万里长征走完了第一步， 往后的路还很长，而且会比现在更加艰难，但我会义无反顾的走下去。
加油吧！A ZA A ZA Fighting!（虽然对韩国人带着一种偏见，讨厌，不过，人家的长处还是要学习的，哈哈，盗用这句话吧！）